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Liu X, Fang H, Liang D, Lei Q, Wang J, Xu F, Liang S, Liang D, Yang F, Li H, Chen J, Ni Y, Xie G, Zeng C. Advancing the application of the analytical renal pathology system in allograft IgA nephropathy patients. Ren Fail 2024; 46:2322043. [PMID: 38425049 PMCID: PMC10911252 DOI: 10.1080/0886022x.2024.2322043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 02/16/2024] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND The analytical renal pathology system (ARPS) based on convolutional neural networks has been used successfully in native IgA nephropathy (IgAN) patients. Considering the similarity of pathologic features, we aim to evaluate the performance of the ARPS in allograft IgAN patients and broaden its implementation. METHODS Biopsy-proven allograft IgAN patients from two different centers were enrolled for internal and external validation. We implemented the ARPS to identify glomerular lesions and intrinsic glomerular cells, and then evaluated its performance. Consistency between the ARPS and pathologists was assessed using intraclass correlation coefficients. The association of digital pathological features with clinical and pathological data was measured. Kaplan-Meier survival curve and cox proportional hazards model were applied to investigate prognosis prediction. RESULTS A total of 56 biopsy-proven allograft IgAN patients from the internal center and 17 biopsy-proven allograft IgAN patients from the external center were enrolled in this study. The ARPS was successfully applied to identify the glomerular lesions (F1-score, 0.696-0.959) and quantify intrinsic glomerular cells (F1-score, 0.888-0.968) in allograft IgAN patients rapidly and precisely. Furthermore, the mesangial hypercellularity score was positively correlated with all mesangial metrics provided by ARPS [Spearman's correlation coefficient (r), 0.439-0.472, and all p values < 0.001]. Besides, a higher allograft survival was noticed among patients in the high-level groups of the maximum and ratio of endothelial cells, as well as the maximum and density of podocytes. CONCLUSION We propose that the ARPS could be implemented in future clinical practice with outstanding capability.
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Affiliation(s)
- Xumeng Liu
- National Clinical Research Center for Kidney Diseases, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Huiwen Fang
- National Clinical Research Center for Kidney Diseases, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Dongmei Liang
- National Clinical Research Center for Kidney Diseases, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Qunjuan Lei
- National Clinical Research Center for Kidney Diseases, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | | | - Feng Xu
- National Clinical Research Center for Kidney Diseases, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Shaoshan Liang
- National Clinical Research Center for Kidney Diseases, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Dandan Liang
- National Clinical Research Center for Kidney Diseases, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Fan Yang
- National Clinical Research Center for Kidney Diseases, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Heng Li
- Kidney Disease Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Zhejiang, China
| | - Jianghua Chen
- Kidney Disease Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Zhejiang, China
| | - Yuan Ni
- Ping An Healthcare Technology, Shanghai, China
| | - Guotong Xie
- Ping An Healthcare Technology, Shanghai, China
| | - Caihong Zeng
- National Clinical Research Center for Kidney Diseases, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
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Lei Q, Hou X, Liu X, Liang D, Fan Y, Xu F, Liang S, Liang D, Yang J, Xie G, Liu Z, Zeng C. Artificial intelligence assists identification and pathologic classification of glomerular lesions in patients with diabetic nephropathy. J Transl Med 2024; 22:397. [PMID: 38684996 PMCID: PMC11059590 DOI: 10.1186/s12967-024-05221-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Accepted: 04/19/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Glomerular lesions are the main injuries of diabetic nephropathy (DN) and are used as a crucial index for pathologic classification. Manual quantification of these morphologic features currently used is semi-quantitative and time-consuming. Automatically quantifying glomerular morphologic features is urgently needed. METHODS A series of convolutional neural networks (CNN) were designed to identify and classify glomerular morphologic features in DN patients. Associations of these digital features with pathologic classification and prognosis were further analyzed. RESULTS Our CNN-based model achieved a 0.928 F1-score for global glomerulosclerosis and 0.953 F1-score for Kimmelstiel-Wilson lesion, further obtained a dice of 0.870 for the mesangial area and F1-score beyond 0.839 for three glomerular intrinsic cells. As the pathologic classes increased, mesangial cell numbers and mesangial area increased, and podocyte numbers decreased (p for all < 0.001), while endothelial cell numbers remained stable (p = 0.431). Glomeruli with Kimmelstiel-Wilson lesion showed more severe podocyte deletion compared to those without (p < 0.001). Furthermore, CNN-based classifications showed moderate agreement with pathologists-based classification, the kappa value between the CNN model 3 and pathologists reached 0.624 (ranging from 0.529 to 0.688, p < 0.001). Notably, CNN-based classifications obtained equivalent performance to pathologists-based classifications on predicting baseline and long-term renal function. CONCLUSION Our CNN-based model is promising in assisting the identification and pathologic classification of glomerular lesions in DN patients.
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Affiliation(s)
- Qunjuan Lei
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, 210009, China
| | - Xiaoshuai Hou
- Ping An Healthcare Technology, 206 Kaibin Road, Shanghai, 200030, China
| | - Xumeng Liu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, 210009, China
| | - Dongmei Liang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, 210009, China
| | - Yun Fan
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, 210009, China
| | - Feng Xu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, 210009, China
| | - Shaoshan Liang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, 210009, China
| | - Dandan Liang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, 210009, China
| | - Jing Yang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, 210009, China
| | - Guotong Xie
- Ping An Healthcare Technology, 206 Kaibin Road, Shanghai, 200030, China.
- Ping An Healthcare and Technology Company Limited, Shanghai, China.
- Ping An International Smart City Technology Co., Shanghai, China.
| | - Zhihong Liu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, 210009, China.
| | - Caihong Zeng
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, Nanjing, 210009, China.
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McKinzie SR, Kaverina N, Schweickart RA, Chaney CP, Eng DG, Pereira BMV, Kestenbaum B, Pippin JW, Wessely O, Shankland SJ. Podocytes from hypertensive and obese mice acquire an inflammatory, senescent, and aged phenotype. Am J Physiol Renal Physiol 2024; 326:F644-F660. [PMID: 38420674 DOI: 10.1152/ajprenal.00417.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/20/2024] [Accepted: 02/20/2024] [Indexed: 03/02/2024] Open
Abstract
Patients with hypertension or obesity can develop glomerular dysfunction characterized by injury and depletion of podocytes. To better understand the molecular processes involved, young mice were treated with either deoxycorticosterone acetate (DOCA) or fed a high-fat diet (HFD) to induce hypertension or obesity, respectively. The transcriptional changes associated with these phenotypes were measured by unbiased bulk mRNA sequencing of isolated podocytes from experimental models and their respective controls. Key findings were validated by immunostaining. In addition to a decrease in canonical proteins and reduced podocyte number, podocytes from both hypertensive and obese mice exhibited a sterile inflammatory phenotype characterized by increases in NLR family pyrin domain containing 3 (NLRP3) inflammasome, protein cell death-1, and Toll-like receptor pathways. Finally, although the mice were young, podocytes in both models exhibited increased expression of senescence and aging genes, including genes consistent with a senescence-associated secretory phenotype. However, there were differences between the hypertension- and obesity-associated senescence phenotypes. Both show stress-induced podocyte senescence characterized by increased p21 and p53. Moreover, in hypertensive mice, this is superimposed upon age-associated podocyte senescence characterized by increased p16 and p19. These results suggest that senescence, aging, and inflammation are critical aspects of the podocyte phenotype in experimental hypertension and obesity in mice.NEW & NOTEWORTHY Hypertension and obesity can lead to glomerular dysfunction in patients, causing podocyte injury and depletion. Here, young mice given deoxycorticosterone acetate or a high-fat diet to induce hypertension or obesity, respectively. mRNA sequencing of isolated podocytes showed transcriptional changes consistent with senescence, a senescent-associated secretory phenotype, and aging, which was confirmed by immunostaining. Ongoing studies are determining the mechanistic roles of the accelerated aging podocyte phenotype in experimental hypertension and obesity.
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Affiliation(s)
- Sierra R McKinzie
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington, United States
| | - Natalya Kaverina
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington, United States
| | | | - Christopher P Chaney
- Department of Medicine, University of Texas Southwestern, Dallas, Texas, United States
| | - Diana G Eng
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington, United States
| | | | - Bryan Kestenbaum
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington, United States
| | - Jeffrey W Pippin
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington, United States
| | - Oliver Wessely
- Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States
| | - Stuart J Shankland
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington, United States
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de Zoysa N, Haruhara K, Nikolic-Paterson DJ, Kerr PG, Ling J, Gazzard SE, Puelles VG, Bertram JF, Cullen-McEwen LA. Podocyte number and glomerulosclerosis indices are associated with the response to therapy for primary focal segmental glomerulosclerosis. Front Med (Lausanne) 2024; 11:1343161. [PMID: 38510448 PMCID: PMC10951056 DOI: 10.3389/fmed.2024.1343161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/19/2024] [Indexed: 03/22/2024] Open
Abstract
Corticosteroid therapy, often in combination with inhibition of the renin-angiotensin system, is first-line therapy for primary focal and segmental glomerulosclerosis (FSGS) with nephrotic-range proteinuria. However, the response to treatment is variable, and therefore new approaches to indicate the response to therapy are required. Podocyte depletion is a hallmark of early FSGS, and here we investigated whether podocyte number, density and/or size in diagnostic biopsies and/or the degree of glomerulosclerosis could indicate the clinical response to first-line therapy. In this retrospective single center cohort study, 19 participants (13 responders, 6 non-responders) were included. Biopsies obtained at diagnosis were prepared for analysis of podocyte number, density and size using design-based stereology. Renal function and proteinuria were assessed 6 months after therapy commenced. Responders and non-responders had similar levels of proteinuria at the time of biopsy and similar kidney function. Patients who did not respond to treatment at 6 months had a significantly higher percentage of glomeruli with global sclerosis than responders (p < 0.05) and glomerulosclerotic index (p < 0.05). Podocyte number per glomerulus in responders was 279 (203-507; median, IQR), 50% greater than that of non-responders (186, 118-310; p < 0.05). These findings suggest that primary FSGS patients with higher podocyte number per glomerulus and less advanced glomerulosclerosis are more likely to respond to first-line therapy at 6 months. A podocyte number less than approximately 216 per glomerulus, a GSI greater than 1 and percentage global sclerosis greater than approximately 20% are associated with a lack of response to therapy. Larger, prospective studies are warranted to confirm whether these parameters may help inform therapeutic decision making at the time of diagnosis of primary FSGS.
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Affiliation(s)
- Natasha de Zoysa
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
| | - Kotaro Haruhara
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
- Division of Nephrology and Hypertension, Jikei University School of Medicine, Tokyo, Japan
| | - David J. Nikolic-Paterson
- Department of Nephrology, Monash Medical Centre, Clayton, VIC, Australia
- Monash University Department of Medicine, Monash Medical Centre, Clayton, VIC, Australia
| | - Peter G. Kerr
- Department of Nephrology, Monash Medical Centre, Clayton, VIC, Australia
- Monash University Department of Medicine, Monash Medical Centre, Clayton, VIC, Australia
| | - Jonathan Ling
- Department of Nephrology, Monash Medical Centre, Clayton, VIC, Australia
- Monash University Department of Medicine, Monash Medical Centre, Clayton, VIC, Australia
| | - Sarah E. Gazzard
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
| | - Victor G. Puelles
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - John F. Bertram
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
- ARC Training Centre for Cell and Tissue Engineering Technologies, Melbourne, VIC, Australia
- ARC Training Centre for Cell and Tissue Engineering Technologies, Brisbane, QLD, Australia
| | - Luise A. Cullen-McEwen
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
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5
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van der Pluijm LA, Koudijs A, Stam W, Roelofs JJ, Danser AJ, Rotmans JI, Gross KW, Pieper MP, van Zonneveld AJ, Bijkerk R. SGLT2 inhibition promotes glomerular repopulation by cells of renin lineage in experimental kidney disease. Acta Physiol (Oxf) 2024; 240:e14108. [PMID: 38314444 PMCID: PMC10923162 DOI: 10.1111/apha.14108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 01/21/2024] [Accepted: 01/23/2024] [Indexed: 02/06/2024]
Abstract
AIM Sodium glucose co-transporter-2 (SGLT2) inhibitors stimulate renal excretion of sodium and glucose and exert renal protective effects in patients with (non-)diabetic chronic kidney disease (CKD) and may as well protect against acute kidney injury (AKI). The mechanism behind this kidney protective effect remains unclear. Juxtaglomerular cells of renin lineage (CoRL) have been demonstrated to function as progenitors for multiple adult glomerular cell types in kidney disease. This study assesses the impact of SGLT2 inhibition on the repopulation of glomerular cells by CoRL and examines their phenotypic commitment. METHODS Experiments were performed in Ren1cre-tdTomato lineage-trace mice. Either 5/6 nephrectomy (5/6NX) modeling CKD or bilateral ischaemia reperfusion injury (bIRI) mimicking AKI was applied, while the SGLT2 inhibitor empagliflozin (10 mg/kg) was administered daily via oral gavage for 14 days. RESULTS Both 5/6NX and bIRI-induced kidney injury increased the number of glomerular CoRL-derived cells. SGLT2 inhibition improved kidney function after 5/6NX, indicated by decreased blood creatinine and urea levels, but not after bIRI. In line with this, empagliflozin in 5/6NX animals resulted in less glomerulosclerosis, while it did not affect histopathological features in bIRI. Treatment with empagliflozin resulted in an increase in the number of CoRL-derived glomerular cells in both 5/6NX and bIRI conditions. Interestingly, SGLT2 inhibition led to more CoRL-derived podocytes in 5/6NX animals, whereas empagliflozin-treated bIRI mice presented with increased levels of parietal epithelial and mesangial cells derived from CoRL. CONCLUSION We conclude that SGLT2 inhibition by empagliflozin promotes CoRL-mediated glomerular repopulation with selective CoRL-derived cell types depending on the type of experimental kidney injury. These findings suggest a previously unidentified mechanism that could contribute to the renoprotective effect of SGLT2 inhibitors.
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Affiliation(s)
- Loïs A.K. van der Pluijm
- Department of Internal Medicine (Nephrology) and the Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Centre, Leiden, the Netherlands
| | - Angela Koudijs
- Department of Internal Medicine (Nephrology) and the Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Centre, Leiden, the Netherlands
| | - Wendy Stam
- Department of Internal Medicine (Nephrology) and the Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Centre, Leiden, the Netherlands
| | - Joris J.T.H. Roelofs
- Department of Pathology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - A.H. Jan Danser
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Joris I. Rotmans
- Department of Internal Medicine (Nephrology) and the Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Centre, Leiden, the Netherlands
| | - Kenneth W. Gross
- Department of Molecular and Cellular Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
| | - Michael P. Pieper
- CardioMetabolic Diseases Research, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach an der Riss, Germany
| | - Anton Jan van Zonneveld
- Department of Internal Medicine (Nephrology) and the Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Centre, Leiden, the Netherlands
| | - Roel Bijkerk
- Department of Internal Medicine (Nephrology) and the Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Centre, Leiden, the Netherlands
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6
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Veloso Pereira BM, Zeng Y, Maggiore JC, Schweickart RA, Eng DG, Kaverina N, McKinzie SR, Chang A, Loretz CJ, Thieme K, Hukriede NA, Pippin JW, Wessely O, Shankland SJ. Podocyte injury at young age causes premature senescence and worsens glomerular aging. Am J Physiol Renal Physiol 2024; 326:F120-F134. [PMID: 37855038 DOI: 10.1152/ajprenal.00261.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/10/2023] [Accepted: 10/10/2023] [Indexed: 10/20/2023] Open
Abstract
As life expectancy continues to rise, age-related diseases are becoming more prevalent. For example, proteinuric glomerular diseases typified by podocyte injury have worse outcomes in the elderly compared with young patients. However, the reasons are not well understood. We hypothesized that injury to nonaged podocytes induces senescence, which in turn augments their aging processes. In primary cultured human podocytes, injury induced by a cytopathic antipodocyte antibody, adriamycin, or puromycin aminonucleoside increased the senescence-related genes CDKN2A (p16INK4a/p14ARF), CDKN2D (p19INK4d), and CDKN1A (p21). Podocyte injury in human kidney organoids was accompanied by increased expression of CDKN2A, CDKN2D, and CDKN1A. In young mice, experimental focal segmental glomerulosclerosis (FSGS) induced by adriamycin and antipodocyte antibody increased the glomerular expression of p16, p21, and senescence-associated β-galactosidase (SA-β-gal). To assess the long-term effects of early podocyte injury-induced senescence, we temporally followed young mice with experimental FSGS through adulthood (12 m of age) and middle age (18 m of age). p16 and Sudan black staining were higher at middle age in mice with earlier FSGS compared with age-matched mice that did not get FSGS when young. This was accompanied by lower podocyte density, reduced canonical podocyte protein expression, and increased glomerular scarring. These results are consistent with injury-induced senescence in young podocytes, leading to increased senescence of podocytes by middle age accompanied by lower podocyte lifespan and health span.NEW & NOTEWORTHY Glomerular function is decreased by aging. However, little is known about the molecular mechanisms involved in age-related glomerular changes and which factors could contribute to a worse glomerular aging process. Here, we reported that podocyte injury in young mice and culture podocytes induced senescence, a marker of aging, and accelerates glomerular aging when compared with healthy aging mice.
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Affiliation(s)
- Beatriz Maria Veloso Pereira
- Division of Nephrology, University of Washington, Seattle, Washington, United States
- Department of Physiology and Biophysics, University of São Paulo, São Paulo, Brazil
| | - Yuting Zeng
- Department of Chemistry, University of Washington, Seattle, Washington, United States
| | - Joseph C Maggiore
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | | | - Diana G Eng
- Division of Nephrology, University of Washington, Seattle, Washington, United States
| | - Natalya Kaverina
- Division of Nephrology, University of Washington, Seattle, Washington, United States
| | - Sierra R McKinzie
- Division of Nephrology, University of Washington, Seattle, Washington, United States
| | - Anthony Chang
- Department of Pathology, University of Chicago, Chicago, Illinois, United States
| | - Carol J Loretz
- Division of Nephrology, University of Washington, Seattle, Washington, United States
| | - Karina Thieme
- Department of Physiology and Biophysics, University of São Paulo, São Paulo, Brazil
| | - Neil A Hukriede
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Jeffrey W Pippin
- Division of Nephrology, University of Washington, Seattle, Washington, United States
| | - Oliver Wessely
- Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States
| | - Stuart J Shankland
- Division of Nephrology, University of Washington, Seattle, Washington, United States
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, United States
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7
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Tian X, Pedigo CE, Li K, Ma X, Bunda P, Pell J, Lek A, Gu J, Zhang Y, Medina Rangel PX, Li W, Schwartze E, Nagata S, Lerner G, Perincheri S, Priyadarshini A, Zhao H, Lek M, Menon MC, Fu R, Ishibe S. Profilin1 is required for prevention of mitotic catastrophe in murine and human glomerular diseases. J Clin Invest 2023; 133:e171237. [PMID: 37847555 PMCID: PMC10721156 DOI: 10.1172/jci171237] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 10/12/2023] [Indexed: 10/18/2023] Open
Abstract
The progression of proteinuric kidney diseases is associated with podocyte loss, but the mechanisms underlying this process remain unclear. Podocytes reenter the cell cycle to repair double-stranded DNA breaks. However, unsuccessful repair can result in podocytes crossing the G1/S checkpoint and undergoing abortive cytokinesis. In this study, we identified Pfn1 as indispensable in maintaining glomerular integrity - its tissue-specific loss in mouse podocytes resulted in severe proteinuria and kidney failure. Our results suggest that this phenotype is due to podocyte mitotic catastrophe (MC), characterized histologically and ultrastructurally by abundant multinucleated cells, irregular nuclei, and mitotic spindles. Podocyte cell cycle reentry was identified using FUCCI2aR mice, and we observed altered expression of cell-cycle associated proteins, such as p21, p53, cyclin B1, and cyclin D1. Podocyte-specific translating ribosome affinity purification and RNA-Seq revealed the downregulation of ribosomal RNA-processing 8 (Rrp8). Overexpression of Rrp8 in Pfn1-KO podocytes partially rescued the phenotype in vitro. Clinical and ultrastructural tomographic analysis of patients with diverse proteinuric kidney diseases further validated the presence of MC podocytes and reduction in podocyte PFN1 expression within kidney tissues. These results suggest that profilin1 is essential in regulating the podocyte cell cycle and its disruption leads to MC and subsequent podocyte loss.
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Affiliation(s)
- Xuefei Tian
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Christopher E. Pedigo
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Ke Li
- Department of Nephrology, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Xiaotao Ma
- Department of Nephrology, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Patricia Bunda
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - John Pell
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | | | - Jianlei Gu
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, USA
| | - Yan Zhang
- Bioinformation Department, Suzhou SITRI Institute of Immunology Co. Ltd., Suzhou, Jiangsu, China
| | - Paulina X. Medina Rangel
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Wei Li
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Eike Schwartze
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Soichiro Nagata
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Gabriel Lerner
- Departments of Surgical Pathology and Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Sudhir Perincheri
- Departments of Surgical Pathology and Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Anupama Priyadarshini
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Hongyu Zhao
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, USA
| | | | - Madhav C. Menon
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Rongguo Fu
- Department of Nephrology, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Shuta Ishibe
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
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8
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Campbell MD, Samuelson AT, Chiao YA, Sweetwyne MT, Ladiges WC, Rabinovitch PS, Marcinek DJ. Intermittent treatment with elamipretide preserves exercise tolerance in aged female mice. GeroScience 2023; 45:2245-2255. [PMID: 36840897 PMCID: PMC10651577 DOI: 10.1007/s11357-023-00754-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 02/09/2023] [Indexed: 02/26/2023] Open
Abstract
The pathology of aging impacts multiple organ systems, including the kidney and skeletal and cardiac muscles. Long-term treatment with the mitochondrial-targeted peptide elamipretide has previously been shown to improve in vivo mitochondrial function in aged mice, which is associated with increased fatigue resistance and treadmill performance, improved cardiovascular diastolic function, and glomerular architecture of the kidney. However, elamipretide is a short tetrameric peptide that is not orally bioavailable, limiting its routes of administration. This study tested whether twice weekly intermittent injections of elamipretide could recapitulate the same functional improvements as continuous long-term infusion. We found that intermittent treatment with elamipretide for 8 months preserved exercise tolerance and left ventricular mass in mice with modest protection of diastolic function and skeletal muscle force production but did not affect kidney function as previously reported using continuous treatment.
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Affiliation(s)
- Matthew D Campbell
- Department of Radiology, University of Washington, Seattle, WA, 98109, USA
| | - Ashton T Samuelson
- Department of Radiology, University of Washington, Seattle, WA, 98109, USA
- Oregon Health Sciences Surgical Residency Program, Portland, OR, 97239, USA
| | - Ying Ann Chiao
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- Aging & Metabolism Research Program MS21, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Mariya T Sweetwyne
- Department of Laboratory Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Warren C Ladiges
- Department of Comparative Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Peter S Rabinovitch
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - David J Marcinek
- Department of Radiology, University of Washington, Seattle, WA, 98109, USA.
- South Lake Union Campus, 850 Republican St., Brotman D142, Box 358050, Seattle, WA, 98109, USA.
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9
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Yoshida T, Latt KZ, Santo BA, Shrivastav S, Zhao Y, Fenaroli P, Chung JY, Hewitt SM, Tutino VM, Sarder P, Rosenberg AZ, Winkler CA, Kopp JB. APOL1 kidney risk variants in glomerular diseases modeled in transgenic mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.27.534273. [PMID: 37090576 PMCID: PMC10120684 DOI: 10.1101/2023.03.27.534273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
APOL1 high-risk variants partially explain the high kidney disease prevalence among African ancestry individuals. Many mechanisms have been reported in cell culture models, but few have been demonstrated in mouse models. Here we characterize two models: (1) HIV-associated nephropathy (HIVAN) Tg26 mice crossed with bacterial artificial chromosome (BAC)/APOL1 transgenic mice and (2) interferon-γ administered to BAC/APOL1 mice. Both models showed exacerbated glomerular disease in APOL1-G1 compared to APOL1-G0 mice. HIVAN model glomerular bulk RNA-seq identified synergistic podocyte-damaging pathways activated by the APOL1-G1 allele and by HIV transgenes. Single-nuclear RNA-seq revealed podocyte-specific patterns of differentially-expressed genes as a function of APOL1 alleles. Eukaryotic Initiation factor-2 pathway was the most activated pathway in the interferon-γ model and the most deactivated pathway in the HIVAN model. HIVAN mouse model podocyte single-nuclear RNA-seq data showed similarity to human focal segmental glomerulosclerosis (FSGS) glomerular bulk RNA-seq data. Furthermore, single-nuclear RNA-seq data from interferon-γ mouse model podocytes (in vivo) showed similarity to human FSGS single-cell RNA-seq data from urine podocytes (ex vivo) and from human podocyte cell lines (in vitro) using bulk RNA-seq. These data highlight differences in the transcriptional effects of the APOL1-G1 risk variant in a model specific manner. Shared differentially expressed genes in podocytes in both mouse models suggest possible novel glomerular damage markers in APOL1 variant-induced diseases. Transcription factor Zbtb16 was downregulated in podocytes and endothelial cells in both models, possibly contributing to glucocorticoid-resistance. In summary, these findings in two mouse models suggest both shared and distinct therapeutic opportunities for APOL1 glomerulopathies.
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Affiliation(s)
- Teruhiko Yoshida
- Kidney Disease Section, Kidney Diseases Branch, NIDDK, NIH, Bethesda, MD
| | - Khun Zaw Latt
- Kidney Disease Section, Kidney Diseases Branch, NIDDK, NIH, Bethesda, MD
| | - Briana A. Santo
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, NY
| | - Shashi Shrivastav
- Kidney Disease Section, Kidney Diseases Branch, NIDDK, NIH, Bethesda, MD
| | - Yongmei Zhao
- Frederick National Laboratory for Cancer Research, NCI, NIH, Frederick, MD
| | - Paride Fenaroli
- Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD
- S.C. Nefrologia e Dialisi, AUSL-IRCCS, Reggio Emilia, Italy
| | | | | | - Vincent M. Tutino
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, NY
| | - Pinaki Sarder
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, NY
- College of Medicine, University of Florida, Gainesville, FL
| | - Avi Z. Rosenberg
- Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD
| | - Cheryl A. Winkler
- Frederick National Laboratory for Cancer Research, NCI, NIH, Frederick, MD
| | - Jeffrey B. Kopp
- Kidney Disease Section, Kidney Diseases Branch, NIDDK, NIH, Bethesda, MD
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10
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Medina Rangel PX, Cross E, Liu C, Pedigo CE, Tian X, Gutiérrez-Calabrés E, Nagata S, Priyadarshini A, Lerner G, Bunda P, Perincheri S, Gu J, Zhao H, Wang Y, Inoue K, Ishibe S. Cell Cycle and Senescence Regulation by Podocyte Histone Deacetylase 1 and 2. J Am Soc Nephrol 2023; 34:433-450. [PMID: 36414418 PMCID: PMC10103311 DOI: 10.1681/asn.2022050598] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 10/17/2022] [Accepted: 11/06/2022] [Indexed: 11/24/2022] Open
Abstract
SIGNIFICANCE STATEMENT The loss of integrity of the glomerular filtration barrier results in proteinuria that is often attributed to podocyte loss. Yet how damaged podocytes are lost remains unknown. Germline loss of murine podocyte-associated Hdac1 and Hdac2 ( Hdac1/2 ) results in proteinuria and collapsing glomerulopathy due to sustained double-stranded DNA damage. Hdac1/2 deletion induces loss of podocyte quiescence, cell cycle entry, arrest in G1, and podocyte senescence, observed both in vivo and in vitro . Through the senescence secretory associated phenotype, podocytes secrete proteins that contribute to their detachment. These results solidify the role of HDACs in cell cycle regulation and senescence, providing important clues in our understanding of how podocytes are lost following injury. BACKGROUND Intact expression of podocyte histone deacetylases (HDAC) during development is essential for maintaining a normal glomerular filtration barrier because of its role in modulating DNA damage and preventing premature senescence. METHODS Germline podocyte-specific Hdac1 and 2 ( Hdac1 / 2 ) double-knockout mice were generated to examine the importance of these enzymes during development. RESULTS Podocyte-specific loss of Hdac1 / 2 in mice resulted in severe proteinuria, kidney failure, and collapsing glomerulopathy. Hdac1 / 2 -deprived podocytes exhibited classic characteristics of senescence, such as senescence-associated β-galactosidase activity and lipofuscin aggregates. In addition, DNA damage, likely caused by epigenetic alterations such as open chromatin conformation, not only resulted in podocyte cell-cycle entry as shown in vivo by Ki67 expression and by FUCCI-2aR mice, but also in p21-mediated cell-cycle arrest. Through the senescence secretory associated phenotype, the damaged podocytes secreted proinflammatory cytokines, growth factors, and matrix metalloproteinases, resulting in subsequent podocyte detachment and loss, evidenced by senescent podocytes in urine. CONCLUSIONS Hdac1 / 2 plays an essential role during development. Loss of these genes in double knockout mice leads to sustained DNA damage and podocyte senescence and loss.
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Affiliation(s)
| | - Elizabeth Cross
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Chang Liu
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Christopher E. Pedigo
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Xuefei Tian
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | | | - Soichiro Nagata
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Anupama Priyadarshini
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Gabriel Lerner
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut
| | - Patricia Bunda
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Sudhir Perincheri
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut
| | - Jianlei Gu
- Department of Biostatistics, Yale University School of Public Health, New Haven, Connecticut
| | - Hongyu Zhao
- Department of Biostatistics, Yale University School of Public Health, New Haven, Connecticut
| | - Ying Wang
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Kazunori Inoue
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Shuta Ishibe
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
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11
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Yang JH, Hayano M, Griffin PT, Amorim JA, Bonkowski MS, Apostolides JK, Salfati EL, Blanchette M, Munding EM, Bhakta M, Chew YC, Guo W, Yang X, Maybury-Lewis S, Tian X, Ross JM, Coppotelli G, Meer MV, Rogers-Hammond R, Vera DL, Lu YR, Pippin JW, Creswell ML, Dou Z, Xu C, Mitchell SJ, Das A, O'Connell BL, Thakur S, Kane AE, Su Q, Mohri Y, Nishimura EK, Schaevitz L, Garg N, Balta AM, Rego MA, Gregory-Ksander M, Jakobs TC, Zhong L, Wakimoto H, El Andari J, Grimm D, Mostoslavsky R, Wagers AJ, Tsubota K, Bonasera SJ, Palmeira CM, Seidman JG, Seidman CE, Wolf NS, Kreiling JA, Sedivy JM, Murphy GF, Green RE, Garcia BA, Berger SL, Oberdoerffer P, Shankland SJ, Gladyshev VN, Ksander BR, Pfenning AR, Rajman LA, Sinclair DA. Loss of epigenetic information as a cause of mammalian aging. Cell 2023; 186:305-326.e27. [PMID: 36638792 PMCID: PMC10166133 DOI: 10.1016/j.cell.2022.12.027] [Citation(s) in RCA: 173] [Impact Index Per Article: 173.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 08/09/2022] [Accepted: 12/15/2022] [Indexed: 01/13/2023]
Abstract
All living things experience an increase in entropy, manifested as a loss of genetic and epigenetic information. In yeast, epigenetic information is lost over time due to the relocalization of chromatin-modifying proteins to DNA breaks, causing cells to lose their identity, a hallmark of yeast aging. Using a system called "ICE" (inducible changes to the epigenome), we find that the act of faithful DNA repair advances aging at physiological, cognitive, and molecular levels, including erosion of the epigenetic landscape, cellular exdifferentiation, senescence, and advancement of the DNA methylation clock, which can be reversed by OSK-mediated rejuvenation. These data are consistent with the information theory of aging, which states that a loss of epigenetic information is a reversible cause of aging.
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Affiliation(s)
- Jae-Hyun Yang
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA.
| | - Motoshi Hayano
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA; Department of Ophthalmology, Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Patrick T Griffin
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - João A Amorim
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA; IIIUC-Institute of Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Michael S Bonkowski
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - John K Apostolides
- Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Elias L Salfati
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | | | | | - Mital Bhakta
- Cantata/Dovetail Genomics, Scotts Valley, CA, USA
| | | | - Wei Guo
- Zymo Research Corporation, Irvine, CA, USA
| | | | - Sun Maybury-Lewis
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Xiao Tian
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Jaime M Ross
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Giuseppe Coppotelli
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Margarita V Meer
- Department of Medicine, Brigham and Women's Hospital, HMS, Boston, MA, USA
| | - Ryan Rogers-Hammond
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Daniel L Vera
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Yuancheng Ryan Lu
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Jeffrey W Pippin
- Division of Nephrology, University of Washington, Seattle, WA, USA
| | - Michael L Creswell
- Division of Nephrology, University of Washington, Seattle, WA, USA; Georgetown University School of Medicine, Washington, DC, USA
| | - Zhixun Dou
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Caiyue Xu
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Abhirup Das
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA; Department of Pharmacology, UNSW, Sydney, NSW, Australia
| | | | - Sachin Thakur
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Alice E Kane
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Qiao Su
- Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Yasuaki Mohri
- Department of Stem Cell Biology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Emi K Nishimura
- Department of Stem Cell Biology, Tokyo Medical and Dental University, Tokyo, Japan
| | | | - Neha Garg
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Ana-Maria Balta
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - Meghan A Rego
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | | | - Tatjana C Jakobs
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, HMS, Boston, MA, USA
| | - Lei Zhong
- The Massachusetts General Hospital Cancer Center, HMS, Boston, MA, USA
| | | | - Jihad El Andari
- Department of Infectious Diseases/Virology, Section Viral Vector Technologies, Medical Faculty, University of Heidelberg, BioQuant, Heidelberg, Germany
| | - Dirk Grimm
- Department of Infectious Diseases/Virology, Section Viral Vector Technologies, Medical Faculty, University of Heidelberg, BioQuant, Heidelberg, Germany
| | - Raul Mostoslavsky
- The Massachusetts General Hospital Cancer Center, HMS, Boston, MA, USA
| | - Amy J Wagers
- Paul F. Glenn Center for Biology of Aging Research, Harvard Stem Cell Institute, Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA; Joslin Diabetes Center, Boston, MA, USA
| | - Kazuo Tsubota
- Department of Ophthalmology, Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Stephen J Bonasera
- Division of Geriatrics, University of Nebraska Medical Center, Durham Research Center II, Omaha, NE, USA
| | - Carlos M Palmeira
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
| | | | | | - Norman S Wolf
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Jill A Kreiling
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - John M Sedivy
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - George F Murphy
- Department of Pathology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Richard E Green
- Department of Biomolecular Engineering, UCSC, Santa Cruz, CA, USA
| | - Benjamin A Garcia
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Shelley L Berger
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | | | | | - Vadim N Gladyshev
- Department of Medicine, Brigham and Women's Hospital, HMS, Boston, MA, USA
| | - Bruce R Ksander
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, HMS, Boston, MA, USA
| | - Andreas R Pfenning
- Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Luis A Rajman
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA
| | - David A Sinclair
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School (HMS), Boston, MA, USA.
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12
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Zhang L, Chen Z, Gao Q, Liu G, Zheng J, Ding F. Preterm birth leads to a decreased number of differentiated podocytes and accelerated podocyte differentiation. Front Cell Dev Biol 2023; 11:1142929. [PMID: 36936687 PMCID: PMC10018169 DOI: 10.3389/fcell.2023.1142929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/20/2023] [Indexed: 03/06/2023] Open
Abstract
Preterm birth was previously identified as a high-risk factor for the long-term development of chronic kidney disease. However, the detailed pattern of podocyte (PD) changes caused by preterm birth and the potential mechanism underlying this process have not been well clarified. In present study, a rat model of preterm birth was established by delivery of pups 2 days early and podometric methods were applied to identify the changes in PDs number caused by preterm birth. In addition, single-cell RNA sequencing (scRNA-seq) and subsequent bioinformatic analysis were performed in the preterm rat kidney to explore the possible mechanism caused by preterm birth. As results, when the kidney completely finished nephrogenesis at the age of 3 weeks, a reduction in the total number of differentiated PDs in kidney sections was detected. In addition, 20 distinct clusters and 12 different cell types were identified after scRNA-seq in preterm rats (postnatal day 2) and full-term rats (postnatal day 0). The numbers of PDs and most types of inherent kidney cells were decreased in the preterm birth model. In addition, 177 genes were upregulated while 82 genes were downregulated in the PDs of full-term rats compared with those of preterm rats. Further functional GO analysis revealed that ribosome-related genes were enriched in PDs from full-term rats, and kidney development-related genes were enriched in PDs from preterm rats. Moreover, known PD-specific and PD precursor genes were highly expressed in PDs from preterm rats, and pseudotemporal analysis showed that PDs were present earlier in preterm rats than in full-term rats. In conclusion, the present study showed that preterm birth could cause a reduction in the number of differentiated PDs and accelerate the differentiation of PDs.
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Affiliation(s)
- Lulu Zhang
- Department of Neonatology, Tianjin Central Hospital of Obstetrics and Gynecology, Tianjin, China
- Tianjin Key Laboratory of Human Development and Reproductive Regulation, Tianjin, China
- Department of Neonatology, Nankai University Maternity Hospital, Tianjin, China
| | - Zhihui Chen
- Department of Neonatology, Tianjin Central Hospital of Obstetrics and Gynecology, Tianjin, China
- Tianjin Key Laboratory of Human Development and Reproductive Regulation, Tianjin, China
- Department of Neonatology, Nankai University Maternity Hospital, Tianjin, China
| | - Qi Gao
- Department of Neonatology, Tianjin Central Hospital of Obstetrics and Gynecology, Tianjin, China
- Tianjin Key Laboratory of Human Development and Reproductive Regulation, Tianjin, China
- Department of Neonatology, Nankai University Maternity Hospital, Tianjin, China
| | - Ge Liu
- Department of Neonatology, Tianjin Central Hospital of Obstetrics and Gynecology, Tianjin, China
- Tianjin Key Laboratory of Human Development and Reproductive Regulation, Tianjin, China
- Department of Neonatology, Nankai University Maternity Hospital, Tianjin, China
| | - Jun Zheng
- Department of Neonatology, Tianjin Central Hospital of Obstetrics and Gynecology, Tianjin, China
- Tianjin Key Laboratory of Human Development and Reproductive Regulation, Tianjin, China
- Department of Neonatology, Nankai University Maternity Hospital, Tianjin, China
- *Correspondence: Jun Zheng, (JZ); Fangrui Ding, (FD)
| | - Fangrui Ding
- Department of Neonatology, Tianjin Central Hospital of Obstetrics and Gynecology, Tianjin, China
- Tianjin Key Laboratory of Human Development and Reproductive Regulation, Tianjin, China
- Department of Neonatology, Nankai University Maternity Hospital, Tianjin, China
- *Correspondence: Jun Zheng, (JZ); Fangrui Ding, (FD)
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13
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Martins ALMDS, Bernardes AB, Ferreira VA, Wanderley DC, Araújo SDA, do Carmo Neto JR, da Silva CA, Lira RCP, Araújo LS, Dos Reis MA, Machado JR. In situ assessment of Mindin as a biomarker of podocyte lesions in diabetic nephropathy. PLoS One 2023; 18:e0284789. [PMID: 37130106 PMCID: PMC10153717 DOI: 10.1371/journal.pone.0284789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 04/07/2023] [Indexed: 05/03/2023] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of chronic kidney disease and end-stage renal failure worldwide. Several mechanisms are involved in the pathogenesis of this disease, which culminate in morphological changes such as podocyte injury. Despite the complex diagnosis and pathogenesis, limited attempts have been made to establish new biomarkers for DN. The higher concentration of Mindin protein in the urine of patients with type 2 diabetes mellitus suggests that it plays a role in DN. Therefore, this study investigated whether in situ protein expression of Mindin can be considered a potential DN biomarker. Fifty renal biopsies from patients diagnosed with DN, 57 with nondiabetic glomerular diseases, including 17 with focal segmental glomerulosclerosis (FSGS), 14 with minimal lesion disease (MLD) and 27 with immunoglobulin A nephropathy (IgAN), and 23 adult kidney samples from autopsies (control group) were evaluated for Mindin expression by immunohistochemistry. Podocyte density was inferred by Wilms' tumor 1 (WT1) immunostaining, while foot process effacement was assessed by transmission electron microscopy. Receiver operative characteristic (ROC) analysis was performed to determine the biomarker sensitivity/specificity. Low podocyte density and increased Mindin expression were observed in all cases of DN, regardless of their class. In the DN group, Mindin expression was significantly higher than that in the FSGS, MCD, IgAN and control groups. Higher Mindin expression was significantly positively correlated with foot process effacement only in class III DN cases. Furthermore, Mindin protein presented high specificity in the biopsies of patients with DN (p < 0.0001). Our data suggest that Mindin may play a role in DN pathogenesis and is a promising biomarker of podocyte lesions.
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Affiliation(s)
- Ana Luisa Monteiro Dos Santos Martins
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Alexia Borges Bernardes
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Verônica Aparecida Ferreira
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - David Campos Wanderley
- Institute of Nephropathology, Center for Electron Microscopy, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Stanley de Almeida Araújo
- Institute of Nephropathology, Center for Electron Microscopy, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - José Rodrigues do Carmo Neto
- Department of Bioscience and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiania, Goiás, Brazil
| | - Crislaine Aparecida da Silva
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Régia Caroline Peixoto Lira
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Liliane Silvano Araújo
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Marlene Antônia Dos Reis
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Juliana Reis Machado
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences of Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
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14
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Haruhara K, Kanzaki G, Tsuboi N. Nephrons, podocytes and chronic kidney disease: Strategic antihypertensive therapy for renoprotection. Hypertens Res 2023; 46:299-310. [PMID: 36224286 PMCID: PMC9899692 DOI: 10.1038/s41440-022-01061-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/06/2022] [Accepted: 09/05/2022] [Indexed: 02/07/2023]
Abstract
Chronic kidney disease (CKD) is one of the strongest risk factors for hypertension, and hypertension can exacerbate the progression of CKD. Thus, the management of CKD and antihypertensive therapy are inextricably linked. Research over the past decades has shown that the human kidney is more diverse than initially thought. Subjects with low nephron endowment are at increased risk of developing CKD and hypertension, which is consistent with the theory of the developmental origins of health and disease. Combined with other lifetime risks of CKD, hypertension may lead to a vicious cycle consisting of podocyte injury, glomerulosclerosis and further loss of nephrons. Of note, recent studies have shown that the number of nephrons correlates well with the number of podocytes, suggesting that these two components are intrinsically linked and may influence each other. Both nephrons and podocytes have no or very limited regenerative capacity and are destined to decrease throughout life. Therefore, one of the best strategies to slow the progression of CKD is to maintain the "numbers" of these essential components necessary to preserve renal function. To this end, both the achievement of an optimal blood pressure and a maximum reduction in urinary protein excretion are essential. Lifestyle modifications and antihypertensive drug therapy must be carefully individualized to address the potential diversity of the kidneys.
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Affiliation(s)
- Kotaro Haruhara
- grid.411898.d0000 0001 0661 2073Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Go Kanzaki
- grid.411898.d0000 0001 0661 2073Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Nobuo Tsuboi
- grid.411898.d0000 0001 0661 2073Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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15
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Sobh MM, El Kannishy G, Moustafa F, Eid R, Hamdy N, Tharwat S. Role of detached podocytes in differentiating between minimal change disease and early focal segmental glomerulosclerosis, can we rely on routine light microscopy? J Nephrol 2022; 35:2313-2324. [PMID: 36350562 PMCID: PMC9700609 DOI: 10.1007/s40620-022-01456-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 08/28/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND Detachment of podocytes represents a turning point in the development of glomerular sclerosis and consequently, of CKD progression. Furthermore, detachment may differentiate minimal change disease (MCD) cases-which have only podocyte effacement-from early focal segmental glomerulosclerosis (FSGS) in which effacement and detachment are observed by electron microscopy. Noteworthy, it is not uncommon for early FSGS to present with clinical presentation and light microscopy (LM) pictures identical to MCD. In our routine practice, we often find cells that lie freely in Bowman's space by LM. In this study, we try to determine whether these cells are detached podocytes that are worth reporting or just an artifact that can be ignored. METHODS To the best of our knowledge, no study has discussed the accuracy of LM in detecting detached podocytes by the routinely used stains. We retrospectively selected 118 cases that were diagnosed as MCD by LM, and searched for detached cells in Bowman's space in their archived, routinely stained LM slides. After that, we tried to find any correlation between the clinical course, detached cells in LM picture and the EM reports. RESULTS LM can significantly detect detached podocytes with a positive predictive value of 93%, specificity of 85%, and sensitivity of 46%. Significant correlations were found between detached cells and degree of proteinuria and late steroid resistance. CONCLUSION Detecting detached podocytes by LM is a specific finding that must be reported whenever detected, as it predicts response to steroids and may be able to differentiate MCD from early FSGS by identifying patients who could have podocytopenia.
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Affiliation(s)
- Mahmoud M Sobh
- Mansoura Nephrology and Dialysis Unit (MNDU), Faculty of Medicine, Mansoura University, Mansoura, Egypt.
| | - Ghada El Kannishy
- Mansoura Nephrology and Dialysis Unit (MNDU), Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Fatma Moustafa
- Department of Pathology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Riham Eid
- Nephrology Unit, Mansoura University Children's Hospital, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Nashwa Hamdy
- Nephrology Unit, Mansoura University Children's Hospital, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Samar Tharwat
- Rheumatology and Immunology Unit, Internal Medicine Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
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16
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Shankland SJ, Wessely O. Zoning in on podocytes. Kidney Int 2022; 102:966-968. [PMID: 36272754 DOI: 10.1016/j.kint.2022.08.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 08/25/2022] [Indexed: 12/14/2022]
Abstract
Podocytes undergo defined morphologic changes during development, homeostasis, and aging, and on injury. Quantitative podometric assessments of podocyte endowment provide a powerful tool to interrogate glomerular health. Expanding this approach to a regional assessment demonstrates that the podocytes from cortical, subcortical, and juxtamedullary glomeruli are not only morphologically heterogeneous per se, but respond differently to stressors, such as age and hypertension. This suggests that zonal glomerular changes harbor critical information to understand glomerulopathies.
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Affiliation(s)
- Stuart J Shankland
- Division of Nephrology, University of Washington, Seattle, Washington, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA.
| | - Oliver Wessely
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA.
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17
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Andrews M, Yoshida T, Henderson CM, Pflaum H, McGregor A, Lieberman JA, de Boer IH, Vaisar T, Himmelfarb J, Kestenbaum B, Chung JY, Hewitt SM, Santo BA, Ginley B, Sarder P, Rosenberg AZ, Murakami T, Kopp JB, Kuklenyik Z, Hoofnagle AN. Variant APOL1 protein in plasma associates with larger particles in humans and mouse models of kidney injury. PLoS One 2022; 17:e0276649. [PMID: 36279295 PMCID: PMC9591058 DOI: 10.1371/journal.pone.0276649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/11/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Genetic variants in apolipoprotein L1 (APOL1), a protein that protects humans from infection with African trypanosomes, explain a substantial proportion of the excess risk of chronic kidney disease affecting individuals with sub-Saharan ancestry. The mechanisms by which risk variants damage kidney cells remain incompletely understood. In preclinical models, APOL1 expressed in podocytes can lead to significant kidney injury. In humans, studies in kidney transplant suggest that the effects of APOL1 variants are predominantly driven by donor genotype. Less attention has been paid to a possible role for circulating APOL1 in kidney injury. METHODS Using liquid chromatography-tandem mass spectrometry, the concentrations of APOL1 were measured in plasma and urine from participants in the Seattle Kidney Study. Asymmetric flow field-flow fractionation was used to evaluate the size of APOL1-containing lipoprotein particles in plasma. Transgenic mice that express wild-type or risk variant APOL1 from an albumin promoter were treated to cause kidney injury and evaluated for renal disease and pathology. RESULTS In human participants, urine concentrations of APOL1 were correlated with plasma concentrations and reduced kidney function. Risk variant APOL1 was enriched in larger particles. In mice, circulating risk variant APOL1-G1 promoted kidney damage and reduced podocyte density without renal expression of APOL1. CONCLUSIONS These results suggest that plasma APOL1 is dynamic and contributes to the progression of kidney disease in humans, which may have implications for treatment of APOL1-associated kidney disease and for kidney transplantation.
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Affiliation(s)
- Michael Andrews
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Teruhiko Yoshida
- Kidney Disease Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Clark M. Henderson
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Hannah Pflaum
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Ayako McGregor
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Joshua A. Lieberman
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Ian H. de Boer
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Kidney Research Institute, University of Washington, Seattle, Washington, United States of America
| | - Tomas Vaisar
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Jonathan Himmelfarb
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Kidney Research Institute, University of Washington, Seattle, Washington, United States of America
| | - Bryan Kestenbaum
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Kidney Research Institute, University of Washington, Seattle, Washington, United States of America
| | - Joon-Yong Chung
- Center for Cancer Research, NCI, NIH, Bethesda, Maryland, United States of America
| | - Stephen M. Hewitt
- Center for Cancer Research, NCI, NIH, Bethesda, Maryland, United States of America
| | - Briana A. Santo
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Brandon Ginley
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Pinaki Sarder
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Avi Z. Rosenberg
- Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, Maryland, United States of America
| | - Taichi Murakami
- Kidney Disease Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Nephrology, Ehime Prefectural Central Hospital, Ehime, Japan
| | - Jeffrey B. Kopp
- Kidney Disease Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Zsuzsanna Kuklenyik
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Andrew N. Hoofnagle
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Kidney Research Institute, University of Washington, Seattle, Washington, United States of America
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18
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Martin CE, Phippen NJ, Keyvani Chahi A, Tilak M, Banerjee SL, Lu P, New LA, Williamson CR, Platt MJ, Simpson JA, Krendel M, Bisson N, Gingras AC, Jones N. Complementary Nck1/2 Signaling in Podocytes Controls α Actinin-4-Mediated Actin Organization, Adhesion, and Basement Membrane Composition. J Am Soc Nephrol 2022; 33:1546-1567. [PMID: 35906089 PMCID: PMC9342632 DOI: 10.1681/asn.2021101343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 04/26/2022] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Maintenance of the kidney filtration barrier requires coordinated interactions between podocytes and the underlying glomerular basement membrane (GBM). GBM ligands bind podocyte integrins, which triggers actin-based signaling events critical for adhesion. Nck1/2 adaptors have emerged as essential regulators of podocyte cytoskeletal dynamics. However, the precise signaling mechanisms mediated by Nck1/2 adaptors in podocytes remain to be fully elucidated. METHODS We generated podocytes deficient in Nck1 and Nck2 and used transcriptomic approaches to profile expression differences. Proteomic techniques identified specific binding partners for Nck1 and Nck2 in podocytes. We used cultured podocytes and mice deficient in Nck1 and/or Nck2, along with podocyte injury models, to comprehensively verify our findings. RESULTS Compound loss of Nck1/2 altered expression of genes involved in actin binding, cell adhesion, and extracellular matrix composition. Accordingly, Nck1/2-deficient podocytes showed defects in actin organization and cell adhesion in vitro, with podocyte detachment and altered GBM morphology present in vivo. We identified distinct interactomes for Nck1 and Nck2 and uncovered a mechanism by which Nck1 and Nck2 cooperate to regulate actin bundling at focal adhesions via α actinin-4. Furthermore, loss of Nck1 or Nck2 resulted in increased matrix deposition in vivo, with more prominent defects in Nck2-deficient mice, consistent with enhanced susceptibility to podocyte injury. CONCLUSION These findings reveal distinct, yet complementary, roles for Nck proteins in regulating podocyte adhesion, controlling GBM composition, and sustaining filtration barrier integrity.
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Affiliation(s)
- Claire E Martin
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.,Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada
| | - Noah J Phippen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Ava Keyvani Chahi
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Manali Tilak
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Sara L Banerjee
- Division of Oncology, Centre de Recherche du Centre Hospitalier Universitaire de Quebec-Laval University, Quebec City, Quebec, Canada.,Centre de Recherche sur le Cancer de l'Université Laval, Quebec City, Quebec, Canada
| | - Peihua Lu
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Laura A New
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Casey R Williamson
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Mathew J Platt
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Jeremy A Simpson
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Mira Krendel
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York
| | - Nicolas Bisson
- Division of Oncology, Centre de Recherche du Centre Hospitalier Universitaire de Quebec-Laval University, Quebec City, Quebec, Canada.,Centre de Recherche sur le Cancer de l'Université Laval, Quebec City, Quebec, Canada.,PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Quebec City, Quebec, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Nina Jones
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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19
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Santo BA, Govind D, Daneshpajouhnejad P, Yang X, Wang XX, Myakala K, Jones BA, Levi M, Kopp JB, Yoshida T, Niedernhofer LJ, Manthey D, Moon KC, Han SS, Zee J, Rosenberg AZ, Sarder P. PodoCount: A Robust, Fully Automated, Whole-Slide Podocyte Quantification Tool. Kidney Int Rep 2022; 7:1377-1392. [PMID: 35694561 PMCID: PMC9174049 DOI: 10.1016/j.ekir.2022.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 02/25/2022] [Accepted: 03/04/2022] [Indexed: 12/13/2022] Open
Abstract
Introduction Podocyte depletion is a histomorphologic indicator of glomerular injury and predicts clinical outcomes. Podocyte estimation methods or podometrics are semiquantitative, technically involved, and laborious. Implementation of high-throughput podometrics in experimental and clinical workflows necessitates an automated podometrics pipeline. Recognizing that computational image analysis offers a robust approach to study cell and tissue structure, we developed and validated PodoCount (a computational tool for automated podocyte quantification in immunohistochemically labeled tissues) using a diverse data set. Methods Whole-slide images (WSIs) of tissues immunostained with a podocyte nuclear marker and periodic acid–Schiff counterstain were acquired. The data set consisted of murine whole kidney sections (n = 135) from 6 disease models and human kidney biopsy specimens from patients with diabetic nephropathy (DN) (n = 45). Within segmented glomeruli, podocytes were extracted and image analysis was applied to compute measures of podocyte depletion and nuclear morphometry. Computational performance evaluation and statistical testing were performed to validate podometric and associated image features. PodoCount was disbursed as an open-source, cloud-based computational tool. Results PodoCount produced highly accurate podocyte quantification when benchmarked against existing methods. Podocyte nuclear profiles were identified with 0.98 accuracy and segmented with 0.85 sensitivity and 0.99 specificity. Errors in podocyte count were bounded by 1 podocyte per glomerulus. Podocyte-specific image features were found to be significant predictors of disease state, proteinuria, and clinical outcome. Conclusion PodoCount offers high-performance podocyte quantitation in diverse murine disease models and in human kidney biopsy specimens. Resultant features offer significant correlation with associated metadata and outcome. Our cloud-based tool will provide end users with a standardized approach for automated podometrics from gigapixel-sized WSIs.
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Affiliation(s)
- Briana A. Santo
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Darshana Govind
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York, USA
| | | | - Xiaoping Yang
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Xiaoxin X. Wang
- Department of Biochemistry, Molecular & Cellular Biology, Georgetown University, Washington, District of Columbia, USA
| | - Komuraiah Myakala
- Department of Biochemistry, Molecular & Cellular Biology, Georgetown University, Washington, District of Columbia, USA
| | - Bryce A. Jones
- Department of Pharmacology and Physiology, Georgetown University, Washington, District of Columbia, USA
| | - Moshe Levi
- Department of Biochemistry, Molecular & Cellular Biology, Georgetown University, Washington, District of Columbia, USA
| | - Jeffrey B. Kopp
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Teruhiko Yoshida
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Laura J. Niedernhofer
- Institute on the Biology of Aging and Metabolism, Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | | | - Kyung Chul Moon
- Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Seung Seok Han
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jarcy Zee
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Avi Z. Rosenberg
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Correspondence: Avi Z. Rosenberg, Department of Pathology, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Building, Room 632D, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205, USA.
| | - Pinaki Sarder
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York, USA
- Pinaki Sarder, Department of Pathology and Anatomical Sciences, University at Buffalo, 955 Main Street, Room 4204, Buffalo, New York 14203, USA.
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20
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Zeitler EM, Jennette JC, Flythe JE, Falk RJ, Poulton JS. High-calorie diet results in reversible obesity-related glomerulopathy in adult zebrafish regardless of dietary fat. Am J Physiol Renal Physiol 2022; 322:F527-F539. [PMID: 35224994 PMCID: PMC8977181 DOI: 10.1152/ajprenal.00018.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/10/2022] [Accepted: 02/22/2022] [Indexed: 11/22/2022] Open
Abstract
Obesity is a risk factor for the development of kidney disease. The role of diet in this association remains undetermined, in part due to practical limitations in studying nutrition in humans. In particular, the relative importance of calorie excess versus dietary macronutrient content is poorly understood. For example, it is unknown if calorie restriction modulates obesity-related kidney pathology. To study the effects of diet-induced obesity in a novel animal model, we treated zebrafish for 8 wk with diets varied in both calorie and fat content. Kidneys were evaluated by light and electron microscopy. We evaluated glomerular filtration barrier function using a dextran permeability assay. We assessed the effect of diet on podocyte sensitivity to injury using an inducible podocyte injury model. We then tested the effect of calorie restriction on the defects caused by diet-induced obesity. Fish fed a high-calorie diet developed glomerulomegaly (mean: 1,211 vs. 1,010 µm2 in controls, P = 0.007), lower podocyte density, foot process effacement, glomerular basement membrane thickening, tubular enlargement (mean: 1,038 vs. 717 µm2 in controls, P < 0.0001), and ectopic lipid deposition. Glomerular filtration barrier dysfunction and increased susceptibility to podocyte injury were observed with high-calorie feeding regardless of dietary fat content. These pathological changes resolved with 4 wk of calorie restriction. Our findings suggest that calorie excess rather than dietary fat drives obesity-related kidney dysfunction and that inadequate podocyte proliferation in response to glomerular enlargement may cause podocyte dysfunction. We also demonstrate the value of zebrafish as a novel model for studying diet in obesity-related kidney disease.NEW & NOTEWORTHY Obesity is a risk factor for kidney disease. The role of diet in this association is difficult to study in humans. In this study, zebrafish fed a high-calorie diet, regardless of fat macronutrient composition, developed glomerulomegaly, foot process effacement, and filtration barrier dysfunction, recapitulating the changes seen in humans with obesity. Calorie restriction reversed the changes. This work suggests that macronutrient composition may be less important than total calories in the development of obesity-related kidney disease.
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Affiliation(s)
- Evan M Zeitler
- Division of Nephrology and Hypertension, Department of Medicine, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - J Charles Jennette
- Division of Nephrology and Hypertension, Department of Medicine, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Nephropathology Division, Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jennifer E Flythe
- Division of Nephrology and Hypertension, Department of Medicine, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Ronald J Falk
- Division of Nephrology and Hypertension, Department of Medicine, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - John S Poulton
- Division of Nephrology and Hypertension, Department of Medicine, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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21
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Rogg M, Maier JI, Van Wymersch C, Helmstädter M, Sammarco A, Lindenmeyer M, Zareba P, Montanez E, Walz G, Werner M, Endlich N, Benzing T, Huber TB, Schell C. α-Parvin Defines a Specific Integrin Adhesome to Maintain the Glomerular Filtration Barrier. J Am Soc Nephrol 2022; 33:786-808. [PMID: 35260418 PMCID: PMC8970443 DOI: 10.1681/asn.2021101319] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/17/2022] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The cell-matrix adhesion between podocytes and the glomerular basement membrane is essential for the integrity of the kidney's filtration barrier. Despite increasing knowledge about the complexity of integrin adhesion complexes, an understanding of the regulation of these protein complexes in glomerular disease remains elusive. METHODS We mapped the in vivo composition of the podocyte integrin adhesome. In addition, we analyzed conditional knockout mice targeting a gene (Parva) that encodes an actin-binding protein (α-parvin), and murine disease models. To evaluate podocytes in vivo, we used super-resolution microscopy, electron microscopy, multiplex immunofluorescence microscopy, and RNA sequencing. We performed functional analysis of CRISPR/Cas9-generated PARVA single knockout podocytes and PARVA and PARVB double knockout podocytes in three- and two-dimensional cultures using specific extracellular matrix ligands and micropatterns. RESULTS We found that PARVA is essential to prevent podocyte foot process effacement, detachment from the glomerular basement membrane, and the development of FSGS. Through the use of in vitro and in vivo models, we identified an inherent PARVB-dependent compensatory module at podocyte integrin adhesion complexes, sustaining efficient mechanical linkage at the filtration barrier. Sequential genetic deletion of PARVA and PARVB induces a switch in structure and composition of integrin adhesion complexes. This redistribution of these complexes translates into a loss of the ventral actin cytoskeleton, decreased adhesion capacity, impaired mechanical resistance, and dysfunctional extracellular matrix assembly. CONCLUSIONS The findings reveal adaptive mechanisms of podocyte integrin adhesion complexes, providing a conceptual framework for therapeutic strategies to prevent podocyte detachment in glomerular disease.
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Affiliation(s)
- Manuel Rogg
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Jasmin I Maier
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Clara Van Wymersch
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Alena Sammarco
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Maja Lindenmeyer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Paulina Zareba
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Eloi Montanez
- Department of Physiological Sciences, Faculty of Medicine, University of Barcelona and Health Sciences and Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Gerd Walz
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Martin Werner
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Schell
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany .,Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Freiburg, Germany
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22
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Schaub JA, O'Connor CL, Shi J, Wiggins RC, Shedden K, Hodgin JB, Bitzer M. Quantitative morphometrics reveals glomerular changes in patients with infrequent segmentally sclerosed glomeruli. J Clin Pathol 2022; 75:121-127. [PMID: 33431484 PMCID: PMC9295693 DOI: 10.1136/jclinpath-2020-207149] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 02/03/2023]
Abstract
AIMS Detection of one segmentally sclerosed glomerulus (SSG) identifies patients with focal segmental glomerulosclerosis (FSGS) but rare SSGs may be missed in kidney biopsies. It is unknown whether alterations of unaffected glomeruli in patients with infrequent SSG can be detected by quantitative morphometrics. METHODS We determined SSG frequency and obtained quantitative morphometrics in glomeruli without a pathologic phenotype in large kidney sections of non-involved kidney tissue from 137 patients undergoing total nephrectomy. We used multivariate modelling to identify morphometrics independently associated with increasing frequency of SSG and Receiver Operator Curve (ROC) analysis to determine the ability of quantitative morphometrics to identify patients with FSGS. We used the geometric distribution to estimate the sensitivity and specificity of a needle biopsy to identify patients with FSGS. RESULTS In seventy-one patients (51.8%), at least one SSG was observed, and of those, 39 (54.9%) had an SSG lesion in less than 2% of all glomeruli (mean of 249 glomeruli per specimen). Increasing percent of SSG was independently associated with decreasing podocyte density and increasing mesangial index in multivariate modelling. For infrequent SSG lesions (<1% of glomeruli), kidney biopsy could miss FSGS diagnosis more than 74% of the time, and podocyte density had an area under the curve (AUC) of 0.77, and mesangial index, an AUC of 0.79 to identify patients with FSGS. CONCLUSIONS More than half of patients had FSGS, although 30% had infrequent SSG. Quantitative morphometrics in glomeruli without pathology, such as podocyte density and mesangial index, identified patients with infrequent SSG and may serve as clinical markers to identify patients with FSGS.
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Affiliation(s)
- Jennifer A Schaub
- Internal Medicine, University of Michigan Michigan Medicine, Ann Arbor, Michigan, USA
| | | | - Jian Shi
- Internal Medicine, University of Michigan Michigan Medicine, Ann Arbor, Michigan, USA
| | - Roger C Wiggins
- Internal Medicine, University of Michigan Michigan Medicine, Ann Arbor, Michigan, USA
| | - Kerby Shedden
- Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA
| | - Jeffrey B Hodgin
- Pathology, University of Michigan Michigan Medicine, Ann Arbor, Michigan, USA
| | - Markus Bitzer
- Internal Medicine, University of Michigan Michigan Medicine, Ann Arbor, Michigan, USA
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23
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Inoue K. Urinary Podocyte Biomarkers and Glomerular Histologic Change. KIDNEY360 2022; 3:407-409. [PMID: 35582191 PMCID: PMC9034819 DOI: 10.34067/kid.0008212021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 01/20/2022] [Indexed: 01/10/2023]
Affiliation(s)
- Kazunori Inoue
- Department of Nephrology, Osaka University Graduate School of Medicine, Osaka, Japan
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24
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Hudkins KL, Li X, Holland AL, Swaminathan S, Alpers CE. Regression of diabetic nephropathy by treatment with empagliflozin in BTBR ob/ob mice. Nephrol Dial Transplant 2021; 37:847-859. [PMID: 34865099 DOI: 10.1093/ndt/gfab330] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The SGLT2 inhibitor empagliflozin lowers blood glucose via reduced tubular reabsorption of filtered glucose and is an important new therapy for diabetic nephropathy (DN). This study tested whether treatment with empagliflozin would ameliorate proteinuria and the pathologic alterations of DN including podocyte number and integrity in the leptin deficient BTBR ob/ob mouse model of DN. METHODS Study cohorts included wild type BTBR mice, untreated diabetic BTBR ob/ob mice, and mice treated with empagliflozin for six weeks after development of established DN at 18 weeks of age. RESULTS Hyperglycemia, proteinuria, serum creatinine, accumulation of mesangial matrix and the extent of mesangiolysis were reversed with empagliflozin treatment. Treatment with empagliflozin resulted in increased podocyte number and podocyte density, improvement in the degree of podocyte foot process effacement and parietal epithelial cell activation. SGLT2 inhibition reduced renal oxidative stress, measured by urinary excretion of markers of RNA/DNA damage and in situ demonstration of decreased carbonyl oxidation. There was no discernable difference in accumulations of advanced glycation endproducts by immunohistochemistry. CONCLUSION The structural improvements seen in BTBR ob/ob mice treated with empagliflozin provide insight into potential long term benefits for humans with DN, for whom there is no comparable biopsy information to identify structural changes effected by SGLT2 inhibition. The findings suggest SGLT2 inhibition may ameliorate diabetic nephropathy through glucose lowering-dependent and -independent mechanisms that lead to podocyte restoration and delay or reversal of the disease progress.
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Affiliation(s)
- Kelly L Hudkins
- Department of Pathology, University of Washington, Seattle WA, USA
| | - Xianwu Li
- Department of Pathology, University of Washington, Seattle WA, USA
| | | | | | - Charles E Alpers
- Department of Pathology, University of Washington, Seattle WA, USA
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25
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Govind D, Becker JU, Miecznikowski J, Rosenberg AZ, Dang J, Tharaux PL, Yacoub R, Thaiss F, Hoyer PF, Manthey D, Lutnick B, Worral AM, Mohammad I, Walavalkar V, Tomaszewski JE, Jen KY, Sarder P. PodoSighter: A Cloud-Based Tool for Label-Free Podocyte Detection in Kidney Whole-Slide Images. J Am Soc Nephrol 2021; 32:2795-2813. [PMID: 34479966 PMCID: PMC8806084 DOI: 10.1681/asn.2021050630] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 08/08/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Podocyte depletion precedes progressive glomerular damage in several kidney diseases. However, the current standard of visual detection and quantification of podocyte nuclei from brightfield microscopy images is laborious and imprecise. METHODS We have developed PodoSighter, an online cloud-based tool, to automatically identify and quantify podocyte nuclei from giga-pixel brightfield whole-slide images (WSIs) using deep learning. Ground-truth to train the tool used immunohistochemically or immunofluorescence-labeled images from a multi-institutional cohort of 122 histologic sections from mouse, rat, and human kidneys. To demonstrate the generalizability of our tool in investigating podocyte loss in clinically relevant samples, we tested it in rodent models of glomerular diseases, including diabetic kidney disease, crescentic GN, and dose-dependent direct podocyte toxicity and depletion, and in human biopsies from steroid-resistant nephrotic syndrome and from human autopsy tissues. RESULTS The optimal model yielded high sensitivity/specificity of 0.80/0.80, 0.81/0.86, and 0.80/0.91, in mouse, rat, and human images, respectively, from periodic acid-Schiff-stained WSIs. Furthermore, the podocyte nuclear morphometrics extracted using PodoSighter were informative in identifying diseased glomeruli. We have made PodoSighter freely available to the general public as turnkey plugins in a cloud-based web application for end users. CONCLUSIONS Our study demonstrates an automated computational approach to detect and quantify podocyte nuclei in standard histologically stained WSIs, facilitating podocyte research, and enabling possible future clinical applications.
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Affiliation(s)
- Darshana Govind
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York
| | - Jan U. Becker
- Institute of Pathology, University Hospital of Cologne, Cologne, Germany
| | | | - Avi Z. Rosenberg
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | | | - Rabi Yacoub
- Department of Internal Medicine, University at Buffalo, Buffalo, New York
| | - Friedrich Thaiss
- Third Medical Department of Clinical Medicine, University Hospital Hamburg Eppendorf, Hamburg, Germany
| | - Peter F. Hoyer
- Pediatric Nephrology, University Hospital Essen, Essen, Germany
| | | | - Brendon Lutnick
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York
| | - Amber M. Worral
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York
| | - Imtiaz Mohammad
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York
| | - Vighnesh Walavalkar
- Department of Pathology, University of California San Francisco, San Francisco, California
| | - John E. Tomaszewski
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York
| | - Kuang-Yu Jen
- Department of Pathology and Laboratory Medicine, University of California, Sacramento, California
| | - Pinaki Sarder
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, New York
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26
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Abstract
The kidney is one of the target organs that may show health disorders as a result of obesity. Obesity-related glomerulopathy (ORG) is a kidney disease category based on a biopsy diagnosis that may occur secondary to obesity. Detailed clinicopathologic observations of ORG have provided significant knowledge regarding obesity-associated renal complications. Glomerulomegaly with focal segmental glomerulosclerosis of perihilar locations is a typical renal histopathologic finding in ORG, which has long been considered to represent a state of single-nephron glomerular hyperfiltration. This hypothesis was recently confirmed in ORG patients by estimating single-nephron glomerular filtration rate using a combined image analysis and biopsy-based stereology. Overshooting in glomerulotubular and tubuloglomerular interactions may lead to glomerular hyperfiltration/hypertension, podocyte failure, tubular protein-traffic overload, and tubulointerstitial scarring, constituting a vicious cycle of a common pathway to the further loss of functioning nephrons and the progression of kidney functional impairment.
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Affiliation(s)
- Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan.
| | - Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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27
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Increasing urinary podocyte mRNA excretion and progressive podocyte loss in kidney contribute to the high risk of long-term renal disease caused by preterm birth. Sci Rep 2021; 11:20650. [PMID: 34667204 PMCID: PMC8526835 DOI: 10.1038/s41598-021-00130-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 10/07/2021] [Indexed: 12/15/2022] Open
Abstract
Podocyte abnormalities are common mechanism driving the progression of glomerular diseases, which account for most chronic kidney diseases (CKDs). However, the role of podocyte in the mechanism of high-risk long-term CKD caused by prematurity has not been well clarified. In present study, urine samples of 86 preterm infants and 32 full-term infants were collected, and podocyte-specific podocin mRNA levels in urine pellet were applied to indicate urinary podocyte mRNA excretion. In addition, in a preterm animal rat model, preterm rats were identified by delivery 2 days early. From the age of 3 weeks-12 months, urine samples were collected to examine podocyte mRNA excretion by measuring podocyte-specific podocin mRNA levels. Kidney samples at the age of 3 weeks, 2 months, and 12 months were collected from 8, 5 and 6 preterm rats and 9, 6 and 8 full-term rats, respectively, to examine podocyte density and podocyte area by measuring the podocyte specific nuclear marker WT-1 and the podocyte specific marker synaptopodin. As results, a more than threefold increase of urinary podocyte-specific podocin mRNA excretion rate was found in preterm infants compared with full-term infants. In addition, there was negative correlation between gestational age at birth and urinary podocin mRNA excretion. In preterm rats, a reduction in the total number of differentiated podocytes in glomeruli and an increased podocyte podocin mRNA excretion rate in urine were detected at the end of kidney differentiation. Moreover, long-term follow-up data in preterm rats showed there was an increased the risk of renal disease indicated by persistent podocyte mRNA loss, proteinuria, and enlarged glomeruli. In conclusion, increasing podocyte mRNA excretion in urine and podocyte loss in kidney led by prematurity drive the progression of long-term abnormal kidney function and could potentially explain the high risk of long-term CKD in preterm infants.
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28
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Urinary podocyte markers in kidney diseases. Clin Chim Acta 2021; 523:315-324. [PMID: 34666027 DOI: 10.1016/j.cca.2021.10.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/17/2021] [Accepted: 10/13/2021] [Indexed: 01/19/2023]
Abstract
Podocytes play an important role in the maintenance of kidney function, and they are the primary focus of many kidney diseases. Podocyte injury results in the shedding of podocyte-derived cellular fragments and podocyte-specific molecular targets into the urine, which may serve as biomarkers of kidney diseases. Intact podocytes, either viable or dead, and podocyte-derived microvesicles could be quantified in the urine by various centrifugation, visualization and culture methods. Podocyte-specific protein targets from the nucleus, cytoplasm, slit-diaphragm, glomerular capillary basement membrane, and cytoskeleton, as well as their corresponding messenger RNA (mRNA), in the urine could be quantified by western blotting, ELISA, or quantitative polymerase chain reaction. Although some of these techniques may be expensive or labor-intensive at present, they may become widely available in the future because of the improvement in technology and automation. The application of urinary podocyte markers for the diagnosis and monitoring of various kidney diseases have been explored but the published data in this area are not sufficiently systematic and lack external validation. Further research should focus on standardizing, comparing, and automizing laboratory methods, as well as defining their added value to the routine clinical tests.
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29
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Naik AS, Wang SQ, Chowdhury M, Aqeel J, O'Connor CL, Wiggins JE, Bitzer M, Wiggins RC. Critical timing of ACEi initiation prevents compensatory glomerular hypertrophy in the remaining single kidney. Sci Rep 2021; 11:19605. [PMID: 34599260 PMCID: PMC8486841 DOI: 10.1038/s41598-021-99124-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/20/2021] [Indexed: 01/05/2023] Open
Abstract
Increasing evidence suggests that single in kidney states (e.g., kidney transplantation and living donation) progressive glomerulosclerosis limits kidney lifespan. Modeling shows that post-nephrectomy compensatory glomerular volume (GV) increase drives podocyte depletion and hypertrophic stress resulting in proteinuria and glomerulosclerosis, implying that GV increase could serve as a therapeutic target to prevent progression. In this report we examine how Angiotensin Converting Enzyme inhibition (ACEi), started before uninephrectomy can reduce compensatory GV increase in wild-type Fischer344 rats. An unbiased computer-assisted method was used for morphometric analysis. Urine Insulin-like growth factor-1 (IGF-1), the major diver of body and kidney growth, was used as a readout. In long-term (40-week) studies of uni-nephrectomized versus sham-nephrectomized rats a 2.2-fold increase in GV was associated with reduced podocyte density, increased proteinuria and glomerulosclerosis. Compensatory GV increase was largely prevented by ACEi started a week before but not after uni-nephrectomy with no measurable impact on long-term eGFR. Similarly, in short-term (14-day) studies, ACEi started a week before uni-nephrectomy reduced both GV increase and urine IGF-1 excretion. Thus, timing of ACEi in relation to uni-nephrectomy had significant impact on post-nephrectomy "compensatory" glomerular growth and outcomes that could potentially be used to improve kidney transplantation and live kidney donation outcomes.
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Affiliation(s)
- Abhijit S Naik
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.
- , F6676 UHS, 1500 E Medical Center Dr, Ann Arbor, MI, 48109-5676, USA.
| | - Su Q Wang
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Mahboob Chowdhury
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Jawad Aqeel
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | | | - Jocelyn E Wiggins
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Markus Bitzer
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Roger C Wiggins
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.
- , 1570B MSRB2, 1150 W Medical Center Dr, Ann Arbor, MI, 48109-5676, USA.
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30
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Haley KE, Elshani M, Um IH, Bell C, Caie PD, Harrison DJ, Reynolds PA. YAP Translocation Precedes Cytoskeletal Rearrangement in Podocyte Stress Response: A Podometric Investigation of Diabetic Nephropathy. Front Physiol 2021; 12:625762. [PMID: 34335284 PMCID: PMC8320019 DOI: 10.3389/fphys.2021.625762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 05/21/2021] [Indexed: 11/13/2022] Open
Abstract
Podocyte loss plays a pivotal role in the pathogenesis of glomerular disease. However, the mechanisms underlying podocyte damage and loss remain poorly understood. Although detachment of viable cells has been documented in experimental Diabetic Nephropathy, correlations between reduced podocyte density and disease severity have not yet been established. YAP, a mechanosensing protein, has recently been shown to correlate with glomerular disease progression, however, the underlying mechanism has yet to be fully elucidated. In this study, we sought to document podocyte density in Diabetic Nephropathy using an amended podometric methodology, and to investigate the interplay between YAP and cytoskeletal integrity during podocyte injury. Podocyte density was quantified using TLE4 and GLEPP1 multiplexed immunofluorescence. Fourteen Diabetic Nephropathy cases were analyzed for both podocyte density and cytoplasmic translocation of YAP via automated image analysis. We demonstrate a significant decrease in podocyte density in Grade III/IV cases (124.5 per 106 μm3) relative to Grade I/II cases (226 per 106 μm3) (Student's t-test, p < 0.001), and further show that YAP translocation precedes cytoskeletal rearrangement following injury. Based on these findings we hypothesize that a significant decrease in podocyte density in late grade Diabetic Nephropathy may be explained by early cytoplasmic translocation of YAP.
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Affiliation(s)
- Kathryn E Haley
- School of Medicine, University of St Andrews, St Andrews, United Kingdom.,Biomedical Sciences Research Complex (BSRC), University of St Andrews, St Andrews, United Kingdom
| | - Mustafa Elshani
- School of Medicine, University of St Andrews, St Andrews, United Kingdom.,Directorate of Laboratory Medicine, Lothian University Hospitals Trust, Royal Infirmary, Edinburgh, United Kingdom
| | - In Hwa Um
- School of Medicine, University of St Andrews, St Andrews, United Kingdom
| | - Cameron Bell
- School of Medicine, University of St Andrews, St Andrews, United Kingdom.,Acute Internal Medicine, Queen Elizabeth University Hospital, Glasgow, United Kingdom
| | - Peter D Caie
- School of Medicine, University of St Andrews, St Andrews, United Kingdom
| | - David J Harrison
- School of Medicine, University of St Andrews, St Andrews, United Kingdom.,Directorate of Laboratory Medicine, Lothian University Hospitals Trust, Royal Infirmary, Edinburgh, United Kingdom
| | - Paul A Reynolds
- School of Medicine, University of St Andrews, St Andrews, United Kingdom.,Biomedical Sciences Research Complex (BSRC), University of St Andrews, St Andrews, United Kingdom
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31
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Attie AD, Schueler KM, Keller MP, Mitok KA, Simonett SP, Hudkins KL, Mehrotra K, Graham MJ, Lee RG, Alpers CE. Reversal of hypertriglyceridemia in diabetic BTBR ob/ob mice does not prevent nephropathy. J Transl Med 2021; 101:935-941. [PMID: 33911188 PMCID: PMC9093019 DOI: 10.1038/s41374-021-00592-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 01/11/2023] Open
Abstract
The etiology of diabetic nephropathy in type 2 diabetes is multifactorial. Sustained hyperglycemia is a major contributor, but additional contributions come from the hypertension, obesity, and hyperlipidemia that are also commonly present in patients with type 2 diabetes and nephropathy. The leptin deficient BTBR ob/ob mouse is a model of type 2 diabetic nephropathy in which hyperglycemia, obesity, and hyperlipidemia, but not hypertension, are present. We have shown that reversal of the constellation of these metabolic abnormalities with leptin replacement can reverse the morphologic and functional manifestations of diabetic nephropathy. Here we tested the hypothesis that reversal specifically of the hypertriglyceridemia, using an antisense oligonucleotide directed against ApoC-III, an apolipoprotein that regulates the interactions of VLDL (very low density lipoproteins) with the LDL receptor, is sufficient to ameliorate the nephropathy of Type 2 diabetes. Antisense treatment resulted in reduction of circulating ApoC-III protein levels and resulted in substantial lowering of triglycerides to near-normal levels in diabetic mice versus controls. Antisense treatment did not ameliorate proteinuria or pathologic manifestations of diabetic nephropathy, including podocyte loss. These studies indicate that pathologic manifestations of diabetic nephropathy are unlikely to be reduced by lipid-lowering therapeutics alone, but does not preclude a role for such interventions to be used in conjunction with other therapeutics commonly employed in the treatment of diabetes and its complications.
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Affiliation(s)
- Alan D Attie
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Kathryn M Schueler
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Mark P Keller
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Kelly A Mitok
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Shane P Simonett
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Kelly L Hudkins
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Kunaal Mehrotra
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | | | | | - Charles E Alpers
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA.
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32
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Yang J, Zhang D, Motojima M, Kume T, Hou Q, Pan Y, Duan A, Zhang M, Jiang S, Hou J, Shi J, Qin Z, Liu Z. Super-Enhancer-Associated Transcription Factors Maintain Transcriptional Regulation in Mature Podocytes. J Am Soc Nephrol 2021; 32:1323-1337. [PMID: 33771836 PMCID: PMC8259645 DOI: 10.1681/asn.2020081177] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 01/30/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Transcriptional programs control cell fate, and identifying their components is critical for understanding diseases caused by cell lesion, such as podocytopathy. Although many transcription factors (TFs) are necessary for cell-state maintenance in glomeruli, their roles in transcriptional regulation are not well understood. METHODS The distribution of H3K27ac histones in human glomerulus cells was analyzed to identify superenhancer-associated TFs, and ChIP-seq and transcriptomics were performed to elucidate the regulatory roles of the TFs. Transgenic animal models of disease were further investigated to confirm the roles of specific TFs in podocyte maintenance. RESULTS Superenhancer distribution revealed a group of potential TFs in core regulatory circuits in human glomerulus cells, including FOXC1/2, WT1, and LMX1B. Integration of transcriptome and cistrome data of FOXC1/2 in mice resolved transcriptional regulation in podocyte maintenance. FOXC1/2 regulated differentiation-associated transcription in mature podocytes. In both humans and animal models, mature podocyte injury was accompanied by deregulation of FOXC1/2 expression, and FOXC1/2 overexpression could protect podocytes in zebrafish. CONCLUSIONS FOXC1/2 maintain podocyte differentiation through transcriptional stabilization. The genome-wide chromatin resources support further investigation of TFs' regulatory roles in glomeruli transcription programs.
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Affiliation(s)
- Jingping Yang
- Medical School of Nanjing University, Nanjing, China,National Clinical Research Center of Kidney Diseases, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Difei Zhang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Masaru Motojima
- Department of Clinical Pharmacology, Tokai University School of Medicine, Isehara, Japan
| | - Tsutomu Kume
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Qing Hou
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Yu Pan
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Aiping Duan
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Mingchao Zhang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Song Jiang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Jinhua Hou
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Jingsong Shi
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Zhaohui Qin
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Zhihong Liu
- Medical School of Nanjing University, Nanjing, China,National Clinical Research Center of Kidney Diseases, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
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33
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Assessment of nephron number and single-nephron glomerular filtration rate in a clinical setting. Hypertens Res 2021; 44:605-617. [PMID: 33526913 DOI: 10.1038/s41440-020-00612-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 01/31/2023]
Abstract
Total nephron counts vary widely between individuals and may affect susceptibility to certain diseases, including hypertension and chronic kidney disease. Detailed analyses of whole kidneys collected from autopsy patients remain the only method for accurately counting nephrons in humans, with no equivalent option in living subjects. Current technological advances have enabled estimations of nephron numbers in vivo, particularly the use of total nephron number and whole-kidney glomerular filtration rate to estimate the mean single-nephron glomerular filtration rate. The use of this method would allow physicians to detect dynamic changes in filtration function at the single-nephron level rather than to simply count the number of nephrons that appear to be functioning. Currently available methods for estimating total nephron number in clinical practice have the potential to overcome limitations associated with autopsy analyses and may therefore pave the way for new therapeutic interventions and improved clinical outcomes.
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34
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Haruhara K, Sasaki T, de Zoysa N, Okabayashi Y, Kanzaki G, Yamamoto I, Harper IS, Puelles VG, Shimizu A, Cullen-McEwen LA, Tsuboi N, Yokoo T, Bertram JF. Podometrics in Japanese Living Donor Kidneys: Associations with Nephron Number, Age, and Hypertension. J Am Soc Nephrol 2021; 32:1187-1199. [PMID: 33627345 PMCID: PMC8259686 DOI: 10.1681/asn.2020101486] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/11/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Podocyte depletion, low nephron number, aging, and hypertension are associated with glomerulosclerosis and CKD. However, the relationship between podometrics and nephron number has not previously been examined. METHODS To investigate podometrics and nephron number in healthy Japanese individuals, a population characterized by a relatively low nephron number, we immunostained single paraffin sections from 30 Japanese living-kidney donors (median age, 57 years) with podocyte-specific markers and analyzed images obtained with confocal microscopy. We used model-based stereology to estimate podometrics, and a combined enhanced-computed tomography/biopsy-specimen stereology method to estimate nephron number. RESULTS The median number of nonsclerotic nephrons per kidney was 659,000 (interquartile range [IQR], 564,000-825,000). The median podocyte number and podocyte density were 518 (IQR, 428-601) per tuft and 219 (IQR, 180-253) per 106μm3, respectively; these values are similar to those previously reported for other races. Total podocyte number per kidney (obtained by multiplying the individual number of nonsclerotic glomeruli by podocyte number per glomerulus) was 376 million (IQR, 259-449 million) and ranged 7.4-fold between donors. On average, these healthy kidneys lost 5.63 million podocytes per kidney per year, with most of this loss associated with glomerular loss resulting from global glomerulosclerosis, rather than podocyte loss from healthy glomeruli. Hypertension was associated with lower podocyte density and larger podocyte volume, independent of age. CONCLUSIONS Estimation of the number of nephrons, podocytes, and other podometric parameters in individual kidneys provides new insights into the relationships between these parameters, age, and hypertension in the kidney. This approach might be of considerable value in evaluating the kidney in health and disease.
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Affiliation(s)
- Kotaro Haruhara
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia,Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takaya Sasaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Natasha de Zoysa
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Go Kanzaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Izumi Yamamoto
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Ian S. Harper
- Monash Micro Imaging, Monash University, Clayton, Australia
| | - Victor G. Puelles
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia,III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Akira Shimizu
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo, Japan
| | - Luise A. Cullen-McEwen
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - John F. Bertram
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia
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35
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Chen DP, Zaky ZS, Schold JD, Herlitz LC, El-Rifai R, Drawz PE, Bruggeman LA, Barisoni L, Hogan SL, Hu Y, O'Toole JF, Poggio ED, Sedor JR. Podocyte density is reduced in kidney allografts with high-risk APOL1 genotypes at transplantation. Clin Transplant 2021; 35:e14234. [PMID: 33511679 DOI: 10.1111/ctr.14234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 11/25/2020] [Accepted: 01/20/2021] [Indexed: 01/23/2023]
Abstract
Variants in apolipoprotein L1 (APOL1) gene are associated with nondiabetic kidney diseases in black subjects and reduced kidney transplant graft survival. Living and deceased black kidney donors (n = 107) were genotyped for APOL1 variants. To determine whether allografts from high-risk APOL1 donors have reduced podocyte densities contributing to allograft failure, we morphometrically estimated podocyte number, glomerular volume, and podocyte density. We compared allograft loss and eGFR trajectories stratified by APOL1 high-risk and low-risk genotypes. Demographic characteristics were similar in high-risk (n = 16) and low-risk (n = 91) donors. Podocyte density was significantly lower in high-risk than low-risk donors (108 ± 26 vs 127 ± 40 podocytes/106 um3 , P = .03). Kaplan-Meier graft survival (high-risk 61% vs. low-risk 91%, p-value = 0.049) and multivariable Cox models (hazard ratio = 2.6; 95% CI, 0.9-7.8) revealed higher graft loss in recipients of APOL1 high-risk allografts over 48 months. More rapid eGFR decline was seen in recipients of high-risk APOL1 allografts (P < .001). At 60 months, eGFR was 27 vs. 51 mL/min/1.73 min2 in recipients of APOL1 high-risk vs low-risk kidney allografts, respectively. Kidneys from high-risk APOL1 donors had worse outcomes versus low-risk APOL1 genotypes. Lower podocyte density in kidneys from high-risk APOL1 donors may increase susceptibility to CKD from subsequent stresses in both the recipients and donors.
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Affiliation(s)
- Dhruti P Chen
- Division of Nephrology, UNC Kidney Center, University of North Carolina, Chapel Hill, NC, USA
| | - Ziad S Zaky
- Glickman Urology and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Jesse D Schold
- Glickman Urology and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA.,Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, USA
| | - Leal C Herlitz
- Pathology and Lab Medicine Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Rasha El-Rifai
- Division of Renal Diseases and Hypertension, University of Minnesota, Minneapolis, MN, USA
| | - Paul E Drawz
- Division of Renal Diseases and Hypertension, University of Minnesota, Minneapolis, MN, USA
| | - Leslie A Bruggeman
- Glickman Urology and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA.,Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Laura Barisoni
- Departments of Pathology and Medicine, Division of Nephrology, Duke University School of Medicine, Durham, NC, USA
| | - Susan L Hogan
- Division of Nephrology, UNC Kidney Center, University of North Carolina, Chapel Hill, NC, USA
| | - Yichun Hu
- Division of Nephrology, UNC Kidney Center, University of North Carolina, Chapel Hill, NC, USA
| | - John F O'Toole
- Glickman Urology and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA.,Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Emilio D Poggio
- Glickman Urology and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA.,Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - John R Sedor
- Glickman Urology and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA.,Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
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36
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Lepa C, Hoppe S, Stöber A, Skryabin BV, Sievers LK, Heitplatz B, Ciarimboli G, Neugebauer U, Lindenmeyer MT, Cohen CD, Drexler HC, Boor P, Weide T, Pavenstädt H, George B. TrkC Is Essential for Nephron Function and Trans-Activates Igf1R Signaling. J Am Soc Nephrol 2021; 32:357-374. [PMID: 33380522 PMCID: PMC8054883 DOI: 10.1681/asn.2020040424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 11/03/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Injury to kidney podocytes often results in chronic glomerular disease and consecutive nephron malfunction. For most glomerular diseases, targeted therapies are lacking. Thus, it is important to identify novel signaling pathways contributing to glomerular disease. Neurotrophic tyrosine kinase receptor 3 (TrkC) is expressed in podocytes and the protein transmits signals to the podocyte actin cytoskeleton. METHODS Nephron-specific TrkC knockout (TrkC-KO) and nephron-specific TrkC-overexpressing (TrkC-OE) mice were generated to dissect the role of TrkC in nephron development and maintenance. RESULTS Both TrkC-KO and TrkC-OE mice exhibited enlarged glomeruli, mesangial proliferation, basement membrane thickening, albuminuria, podocyte loss, and aspects of FSGS during aging. Igf1 receptor (Igf1R)-associated gene expression was dysregulated in TrkC-KO mouse glomeruli. Phosphoproteins associated with insulin, erb-b2 receptor tyrosine kinase (Erbb), and Toll-like receptor signaling were enriched in lysates of podocytes treated with the TrkC ligand neurotrophin-3 (Nt-3). Activation of TrkC by Nt-3 resulted in phosphorylation of the Igf1R on activating tyrosine residues in podocytes. Igf1R phosphorylation was increased in TrkC-OE mouse kidneys while it was decreased in TrkC-KO kidneys. Furthermore, TrkC expression was elevated in glomerular tissue of patients with diabetic kidney disease compared with control glomerular tissue. CONCLUSIONS Our results show that TrkC is essential for maintaining glomerular integrity. Furthermore, TrkC modulates Igf-related signaling in podocytes.
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Affiliation(s)
- Carolin Lepa
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Sascha Hoppe
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Antje Stöber
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Boris V. Skryabin
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), Westfälische-Wilhelms-University, Münster, Germany
| | | | - Barbara Heitplatz
- Gerhard-Domagk Institute for Pathology, University Hospital Münster, Münster, Germany
| | | | - Ute Neugebauer
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Maja T. Lindenmeyer
- III. Medizinische Klinik und Poliklinik, University Hospital Hamburg-Eppendorf, Germany
| | - Clemens D. Cohen
- Klinik für Nieren-, Hochdruck- und Rheumaerkrankungen, München Klinik Harlaching, Germany
| | - Hannes C.A. Drexler
- Mass Spectrometry Unit, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Peter Boor
- Institute of Pathology and Department of Nephrology, University Hospital Aachen, Rheinisch-Westfälische Technische Hochschule Aachen, Aachen, Germany
| | - Thomas Weide
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | | | - Britta George
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
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37
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Tian X, Inoue K, Zhang Y, Wang Y, Sperati CJ, Pedigo CE, Zhao T, Yan M, Groener M, Moledina DG, Ebenezer K, Li W, Zhang Z, Liebermann DA, Greene L, Greer P, Parikh CR, Ishibe S. Inhibiting calpain 1 and 2 in cyclin G associated kinase-knockout mice mitigates podocyte injury. JCI Insight 2020; 5:142740. [PMID: 33208557 PMCID: PMC7710277 DOI: 10.1172/jci.insight.142740] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/08/2020] [Indexed: 12/27/2022] Open
Abstract
Evidence for reduced expression of cyclin G associated kinase (GAK) in glomeruli of patients with chronic kidney disease was observed in the Nephroseq human database, and GAK was found to be associated with the decline in kidney function. To examine the role of GAK, a protein that functions to uncoat clathrin during endocytosis, we generated podocyte-specific Gak-knockout mice (Gak-KO), which developed progressive proteinuria and kidney failure with global glomerulosclerosis. We isolated glomeruli from the mice carrying the mutation to perform messenger RNA profiling and unearthed evidence for dysregulated podocyte calpain protease activity as an important contributor to progressive podocyte damage. Treatment with calpain inhibitor III specifically inhibited calpain-1/-2 activities, mitigated the degree of proteinuria and glomerulosclerosis, and led to a striking increase in survival in the Gak-KO mice. Podocyte-specific deletion of Capns1, essential for calpain-1 and calpain-2 activities, also improved proteinuria and glomerulosclerosis in Gak-KO mice. Increased podocyte calpain activity-mediated proteolysis of IκBα resulted in increased NF-κB p65-induced expression of growth arrest and DNA-damage-inducible 45 beta in the Gak-KO mice. Our results suggest that loss of podocyte-associated Gak induces glomerular injury secondary to calcium dysregulation and aberrant calpain activation, which when inhibited, can provide a protective role.
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MESH Headings
- Animals
- Calpain/antagonists & inhibitors
- Diabetic Nephropathies/etiology
- Diabetic Nephropathies/metabolism
- Diabetic Nephropathies/pathology
- Diabetic Nephropathies/therapy
- Female
- Glomerulosclerosis, Focal Segmental/etiology
- Glomerulosclerosis, Focal Segmental/metabolism
- Glomerulosclerosis, Focal Segmental/pathology
- Glomerulosclerosis, Focal Segmental/therapy
- Humans
- Intracellular Signaling Peptides and Proteins/genetics
- Intracellular Signaling Peptides and Proteins/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Podocytes/metabolism
- Podocytes/pathology
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Protein Serine-Threonine Kinases/physiology
- Renal Insufficiency, Chronic/etiology
- Renal Insufficiency, Chronic/metabolism
- Renal Insufficiency, Chronic/pathology
- Renal Insufficiency, Chronic/therapy
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Affiliation(s)
- Xuefei Tian
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Kazunori Inoue
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yan Zhang
- State Key Laboratory of Organ Failure Research, Southern Medical University, Nanfang Hospital, Guangzhou, China
- Center for Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Ying Wang
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - C. John Sperati
- Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christopher E. Pedigo
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Tingting Zhao
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Meihua Yan
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Marwin Groener
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Dennis G. Moledina
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Karen Ebenezer
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Wei Li
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Zhenhai Zhang
- State Key Laboratory of Organ Failure Research, Southern Medical University, Nanfang Hospital, Guangzhou, China
- Center for Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Dan A. Liebermann
- Fels Institute of Cancer Research and Molecular Biology and Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania USA
| | - Lois Greene
- Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | - Peter Greer
- Queen’s Cancer Research Institute, Kingston, Ontario, Canada
| | - Chirag R. Parikh
- Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Shuta Ishibe
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
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38
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da Silva CA, Monteiro MLGDR, Araújo LS, Urzedo MG, Rocha LB, dos Reis MA, Machado JR. In situ evaluation of podocytes in patients with focal segmental glomerulosclerosis and minimal change disease. PLoS One 2020; 15:e0241745. [PMID: 33147279 PMCID: PMC7641434 DOI: 10.1371/journal.pone.0241745] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 10/21/2020] [Indexed: 12/18/2022] Open
Abstract
Podocyte injury in focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) results from the imbalance between adaptive responses that maintain homeostasis and cellular dysfunction that can culminate in cell death. Therefore, an in situ analysis was performed to detect morphological changes related to cell death and autophagy in renal biopsies from adult patients with podocytopathies. Forty-nine renal biopsies from patients with FSGS (n = 22) and MCD (n = 27) were selected. In situ expression of Wilms Tumor 1 protein (WT1), light chain microtubule 1-associated protein (LC3) and caspase-3 protein were evaluated by immunohistochemistry. The foot process effacement and morphological alterations related to podocyte cell death and autophagy were analyzed with transmission electronic microscopy. Reduction in the density of WT1-labeled podocytes was observed for FSGS and MCD cases as compared to controls. Foot process width (FPW) in control group was lower than in cases of podocytopathies. In FSGS group, FPW was significantly higher than in MCD group and correlated with proteinuria. A density of LC3-labeled podocytes and the number of autophagosomes in podocytes/ pedicels were higher in the MCD group than in the FSGS group. The number of autophagosomes correlated positively with the estimated glomerular filtration rate in cases of MCD. The density of caspase-3-labeled podocytes in FSGS and MCD was higher than control group, and a higher number of podocytes with an evidence of necrosis was detected in FSGS cases than in MCD and control cases. Podocytes from patients diagnosed with FSGS showed more morphological and functional alterations resulting from a larger number of lesions and reduced cell adaptation.
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Affiliation(s)
- Crislaine Aparecida da Silva
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Maria Luíza Gonçalves dos Reis Monteiro
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Liliane Silvano Araújo
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Monise Gini Urzedo
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Lenaldo Branco Rocha
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Marlene Antônia dos Reis
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Juliana Reis Machado
- Department of Pathology, Genetics and Evolution, Discipline of General Pathology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
- * E-mail:
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39
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Barisoni L, Lafata KJ, Hewitt SM, Madabhushi A, Balis UGJ. Digital pathology and computational image analysis in nephropathology. Nat Rev Nephrol 2020; 16:669-685. [PMID: 32848206 PMCID: PMC7447970 DOI: 10.1038/s41581-020-0321-6] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2020] [Indexed: 12/17/2022]
Abstract
The emergence of digital pathology - an image-based environment for the acquisition, management and interpretation of pathology information supported by computational techniques for data extraction and analysis - is changing the pathology ecosystem. In particular, by virtue of our new-found ability to generate and curate digital libraries, the field of machine vision can now be effectively applied to histopathological subject matter by individuals who do not have deep expertise in machine vision techniques. Although these novel approaches have already advanced the detection, classification, and prognostication of diseases in the fields of radiology and oncology, renal pathology is just entering the digital era, with the establishment of consortia and digital pathology repositories for the collection, analysis and integration of pathology data with other domains. The development of machine-learning approaches for the extraction of information from image data, allows for tissue interrogation in a way that was not previously possible. The application of these novel tools are placing pathology centre stage in the process of defining new, integrated, biologically and clinically homogeneous disease categories, to identify patients at risk of progression, and shifting current paradigms for the treatment and prevention of kidney diseases.
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Affiliation(s)
- Laura Barisoni
- Department of Pathology, Duke University, Durham, NC, USA.
- Department of Medicine, Division of Nephrology, Duke University, Durham, NC, USA.
| | - Kyle J Lafata
- Department of Radiology, Duke University, Durham, NC, USA
- Department of Radiation Oncology, Duke University, Durham, NC, USA
| | - Stephen M Hewitt
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Anant Madabhushi
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Louis Stokes Veterans Administration Medical Center, Cleveland, OH, USA
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40
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Kaverina NV, Eng DG, Miner JH, Pippin JW, Shankland SJ. Parietal epithelial cell differentiation to a podocyte fate in the aged mouse kidney. Aging (Albany NY) 2020; 12:17601-17624. [PMID: 32858527 PMCID: PMC7521511 DOI: 10.18632/aging.103788] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/29/2020] [Indexed: 01/24/2023]
Abstract
Healthy aging is typified by a progressive and absolute loss of podocytes over the lifespan of animals and humans. To test the hypothesis that a subset of glomerular parietal epithelial cell (PEC) progenitors transition to a podocyte fate with aging, dual reporter PEC-rtTA|LC1|tdTomato|Nphs1-FLPo|FRT-EGFP mice were generated. PECs were inducibly labeled with a tdTomato reporter, and podocytes were constitutively labeled with an EGFP reporter. With advancing age (14 and 24 months) glomeruli in the juxta-medullary cortex (JMC) were more severely injured than those in the outer cortex (OC). In aged mice (24m), injured glomeruli with lower podocyte number (41% decrease), showed more PEC migration and differentiation to a podocyte fate than mildly injured or healthy glomeruli. PECs differentiated to a podocyte fate had ultrastructural features of podocytes and co-expressed the podocyte markers podocin, nephrin, p57 and VEGF164, but not markers of mesangial (Perlecan) or endothelial (ERG) cells. PECs differentiated to a podocyte fate did not express CD44, a marker of PEC activation. Taken together, we demonstrate that a subpopulation of PECs differentiate to a podocyte fate predominantly in injured glomeruli in mice of advanced age.
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Affiliation(s)
| | - Diana G. Eng
- Division of Nephrology, University of Washington, Seattle, WA 98195, USA
| | - Jeffrey H. Miner
- Division of Nephrology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Jeffrey W. Pippin
- Division of Nephrology, University of Washington, Seattle, WA 98195, USA
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41
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Van den Berge BT, Maas RJ. Nephron Number as Predictor of Corticosteroid Response in Adult Minimal Change Disease. Kidney Med 2020; 2:520-522. [PMID: 33090125 PMCID: PMC7568060 DOI: 10.1016/j.xkme.2020.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Bartholomeus T Van den Berge
- Department of Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Pathology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rutger J Maas
- Department of Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands
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42
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Jayapandian CP, Chen Y, Janowczyk AR, Palmer MB, Cassol CA, Sekulic M, Hodgin JB, Zee J, Hewitt SM, O'Toole J, Toro P, Sedor JR, Barisoni L, Madabhushi A. Development and evaluation of deep learning-based segmentation of histologic structures in the kidney cortex with multiple histologic stains. Kidney Int 2020; 99:86-101. [PMID: 32835732 PMCID: PMC8414393 DOI: 10.1016/j.kint.2020.07.044] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 06/29/2020] [Accepted: 07/24/2020] [Indexed: 12/21/2022]
Abstract
The application of deep learning for automated segmentation (delineation of boundaries) of histologic primitives (structures) from whole slide images can facilitate the establishment of novel protocols for kidney biopsy assessment. Here, we developed and validated deep learning networks for the segmentation of histologic structures on kidney biopsies and nephrectomies. For development, we examined 125 biopsies for Minimal Change Disease collected across 29 NEPTUNE enrolling centers along with 459 whole slide images stained with Hematoxylin & Eosin (125), Periodic Acid Schiff (125), Silver (102), and Trichrome (107) divided into training, validation and testing sets (ratio 6:1:3). Histologic structures were manually segmented (30048 total annotations) by five nephropathologists. Twenty deep learning models were trained with optimal digital magnification across the structures and stains. Periodic Acid Schiff-stained whole slide images yielded the best concordance between pathologists and deep learning segmentation across all structures (F-scores: 0.93 for glomerular tufts, 0.94 for glomerular tuft plus Bowman’s capsule, 0.91 for proximal tubules, 0.93 for distal tubular segments, 0.81 for peritubular capillaries, and 0.85 for arteries and afferent arterioles). Optimal digital magnifications were 5X for glomerular tuft/tuft plus Bowman’s capsule, 10X for proximal/distal tubule, arteries and afferent arterioles, and 40X for peritubular capillaries. Silver stained whole slide images yielded the worst deep learning performance. Thus, this largest study to date adapted deep learning for the segmentation of kidney histologic structures across multiple stains and pathology laboratories. All data used for training and testing and a detailed online tutorial will be publicly available.
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Affiliation(s)
- Catherine P Jayapandian
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.
| | - Yijiang Chen
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Andrew R Janowczyk
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA; Precision Oncology Center, Lausanne University Hospital, Vaud, Switzerland
| | - Matthew B Palmer
- Department of Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Miroslav Sekulic
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA; Department of Pathology, University Hospitals of Cleveland, Cleveland, Ohio, USA
| | - Jeffrey B Hodgin
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jarcy Zee
- Department of Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stephen M Hewitt
- Laboratory of Pathology, National Institutes of Health, National Cancer Institute, Bethesda, Maryland, USA
| | - John O'Toole
- Lerner Research and Glickman Urology and Kidney Institutes, Cleveland Clinic, Cleveland, Ohio, USA
| | - Paula Toro
- Department of Pathology, Universidad Nacional de Colombia, Bogotá, Colombia
| | - John R Sedor
- Lerner Research and Glickman Urology and Kidney Institutes, Cleveland Clinic, Cleveland, Ohio, USA; Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Laura Barisoni
- Department of Pathology and Medicine, Division of Nephrology, Duke University, Durham, North Carolina, USA
| | - Anant Madabhushi
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA; Louis Stokes Cleveland Veterans Administration Medical Center, Cleveland, Ohio, USA
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43
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Motrapu M, Świderska MK, Mesas I, Marschner JA, Lei Y, Martinez Valenzuela L, Fu J, Lee K, Angelotti ML, Antonelli G, Romagnani P, Anders HJ, Anguiano L. Drug Testing for Residual Progression of Diabetic Kidney Disease in Mice Beyond Therapy with Metformin, Ramipril, and Empagliflozin. J Am Soc Nephrol 2020; 31:1729-1745. [PMID: 32576600 DOI: 10.1681/asn.2019070703] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 04/24/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Progression of CKD in type 2 diabetes, despite dual inhibition of sodium-glucose transporter-2 and the renin-angiotensin system, remains a concern. Bromoindirubin-3'-oxime (BIO), previously reported to promote podocyte survival and regeneration, is a candidate additional drug to elicit renoprotective effects beyond therapy with metformin, ramipril, and empagliflozin (MRE). Evaluating a drug with standard therapeutics more closely mimics the clinical setting than evaluating the drug alone. METHODS Uninephrectomized BKS-Lepr-/- (db/db) mice treated with or without MRE served as a model of progressive CKD in type 2 diabetes. Mice on or off MRE were randomized to only 4 weeks of add-on BIO or vehicle. The primary end point was slope of GFR (ΔGFR). RESULTS Four weeks of MRE treatment alone did not affect ΔGFR, but significantly attenuated hyperglycemia, albuminuria, and glomerulosclerosis and increased podocyte filtration slit density, as assessed by STED super-resolution microscopy upon tissue clearing. BIO alone improved albuminuria, podocyte density in superficial and juxtamedullary nephrons, and podocyte filtration slit density. MRE+BIO combination therapy had additive protective effects on ΔGFR, glomerulosclerosis, podocyte density in juxtamedullary nephrons, and filtration slit density. CONCLUSIONS Add-on treatment with BIO for only 4 weeks attenuates progression of CKD beyond MRE therapy in mice with type 2 diabetes. Additional drug combinations may help to further delay ESKD in type 2 diabetes.
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Affiliation(s)
- Manga Motrapu
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, Munich, Germany
| | - Monika Katarzyna Świderska
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, Munich, Germany
| | - Irene Mesas
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, Munich, Germany
| | - Julian Aurelio Marschner
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, Munich, Germany
| | - Yutian Lei
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, Munich, Germany
| | - Laura Martinez Valenzuela
- Nephrology Unit, Bellvitge University Hospital, Hospitalet de Llobregat, de Llobregat, Spain.,IDIBELL Biomedical Research Institute, Hospitalet de Llobregat, de Llobregat, Spain
| | - Jia Fu
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Kyung Lee
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Maria Lucia Angelotti
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Giulia Antonelli
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Paola Romagnani
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy.,Nephrology and Dialysis Unit, Meyer Children's University Hospital, Florence, Italy
| | - Hans-Joachim Anders
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, Munich, Germany
| | - Lidia Anguiano
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, Munich, Germany
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Okabayashi Y, Tsuboi N, Sasaki T, Haruhara K, Kanzaki G, Koike K, Shimizu A, D'Agati VD, Yokoo T. Single-Nephron GFR in Patients With Obesity-Related Glomerulopathy. Kidney Int Rep 2020; 5:1218-1227. [PMID: 32775821 PMCID: PMC7403629 DOI: 10.1016/j.ekir.2020.05.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 04/28/2020] [Accepted: 05/04/2020] [Indexed: 02/07/2023] Open
Abstract
Introduction Obesity-related glomerulopathy (ORG) is a slowly progressive kidney disease occurring in association with obesity. It is characterized histopathologically by glomerulomegaly, likely caused by single-nephron hyperfiltration that has not been demonstrated in humans because of technical difficulty in measuring single-nephron glomerular filtration rate (SNGFR) in the clinical setting. Methods Total glomerular number per kidney, with or without global glomerulosclerosis, was estimated by the combination of cortical volume assessment via unenhanced computed tomography and biopsy-based stereology. Mean glomerular volume was calculated from the measured area of glomerular tufts. Both SNGFR and single-nephron urinary protein excretion (SNUPE) were estimated by dividing values for estimated glomerular filtration rate and urinary protein excretion by the number of nonsclerotic glomeruli. Living kidney donors were used as healthy controls. Results A total of 48 ORG patients with average nonsclerotic glomerular numbers of 456,000 ± 235,000 per kidney were included. The values for SNGFR in ORG patients with chronic kidney disease (CKD) stages 1 and 2 were higher than for nonobese and obese controls (97 ± 43 vs. 59 ± 21 vs. 64 ± 21 nl/min, respectively, P = 0.001). Nonsclerotic glomerular number decreased with advancing stages of renal functional impairment. The presence of ORG with more advanced CKD stages was associated with lower SNGFR and marked elevation in SNUPE levels, with no difference in the mean glomerular volume between the stages. Conclusions These results provide functional evidence for single-nephron hyperfiltration in patients with ORG, and identify compensatory failure to maintain effective SNGFR as a feature of advanced-stage ORG.
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Affiliation(s)
- Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takaya Sasaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kotaro Haruhara
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Go Kanzaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kentaro Koike
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Akira Shimizu
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo, Japan
| | - Vivette D D'Agati
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York, USA
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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45
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Giralt-López A, Molina-Van den Bosch M, Vergara A, García-Carro C, Seron D, Jacobs-Cachá C, Soler MJ. Revisiting Experimental Models of Diabetic Nephropathy. Int J Mol Sci 2020; 21:ijms21103587. [PMID: 32438732 PMCID: PMC7278948 DOI: 10.3390/ijms21103587] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 12/12/2022] Open
Abstract
Diabetes prevalence is constantly increasing and, nowadays, it affects more than 350 million people worldwide. Therefore, the prevalence of diabetic nephropathy (DN) has also increased, becoming the main cause of end-stage renal disease (ESRD) in the developed world. DN is characterized by albuminuria, a decline in glomerular filtration rate (GFR), hypertension, mesangial matrix expansion, glomerular basement membrane thickening, and tubulointerstitial fibrosis. The therapeutic advances in the last years have been able to modify and delay the natural course of diabetic kidney disease (DKD). Nevertheless, there is still an urgent need to characterize the pathways that are involved in DN, identify risk biomarkers and prevent kidney failure in diabetic patients. Rodent models provide valuable information regarding how DN is set and its progression through time. Despite the utility of these models, kidney disease progression depends on the diabetes induction method and susceptibility to diabetes of each experimental strain. The classical DN murine models (Streptozotocin-induced, Akita, or obese type 2 models) do not develop all of the typical DN features. For this reason, many models have been crossed to a susceptible genetic background. Knockout and transgenic strains have also been created to generate more robust models. In this review, we will focus on the description of the new DN rodent models and, additionally, we will provide an overview of the available methods for renal phenotyping.
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Affiliation(s)
- Anna Giralt-López
- Nephrology Research Group, Vall d’Hebrón Institut de Recerca, 08035 Barcelona, Spain; (A.G.-L.); (M.M.-V.d.B.); (A.V.); (C.G.-C.); (D.S.)
| | - Mireia Molina-Van den Bosch
- Nephrology Research Group, Vall d’Hebrón Institut de Recerca, 08035 Barcelona, Spain; (A.G.-L.); (M.M.-V.d.B.); (A.V.); (C.G.-C.); (D.S.)
| | - Ander Vergara
- Nephrology Research Group, Vall d’Hebrón Institut de Recerca, 08035 Barcelona, Spain; (A.G.-L.); (M.M.-V.d.B.); (A.V.); (C.G.-C.); (D.S.)
- Nephrology Department, Vall d’Hebrón Hospital, 08035 Barcelona, Spain
| | - Clara García-Carro
- Nephrology Research Group, Vall d’Hebrón Institut de Recerca, 08035 Barcelona, Spain; (A.G.-L.); (M.M.-V.d.B.); (A.V.); (C.G.-C.); (D.S.)
- Nephrology Department, Vall d’Hebrón Hospital, 08035 Barcelona, Spain
| | - Daniel Seron
- Nephrology Research Group, Vall d’Hebrón Institut de Recerca, 08035 Barcelona, Spain; (A.G.-L.); (M.M.-V.d.B.); (A.V.); (C.G.-C.); (D.S.)
- Nephrology Department, Vall d’Hebrón Hospital, 08035 Barcelona, Spain
| | - Conxita Jacobs-Cachá
- Nephrology Research Group, Vall d’Hebrón Institut de Recerca, 08035 Barcelona, Spain; (A.G.-L.); (M.M.-V.d.B.); (A.V.); (C.G.-C.); (D.S.)
- Correspondence: (C.J.-C.); (M.J.S.)
| | - Maria José Soler
- Nephrology Research Group, Vall d’Hebrón Institut de Recerca, 08035 Barcelona, Spain; (A.G.-L.); (M.M.-V.d.B.); (A.V.); (C.G.-C.); (D.S.)
- Nephrology Department, Vall d’Hebrón Hospital, 08035 Barcelona, Spain
- Correspondence: (C.J.-C.); (M.J.S.)
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46
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Hudkins KL, Wietecha TA, Steegh F, Alpers CE. Beneficial effect on podocyte number in experimental diabetic nephropathy resulting from combined atrasentan and RAAS inhibition therapy. Am J Physiol Renal Physiol 2020; 318:F1295-F1305. [PMID: 32249614 DOI: 10.1152/ajprenal.00498.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Podocyte loss and proteinuria are both key features of human diabetic nephropathy (DN). The leptin-deficient BTBR mouse strain with the ob/ob mutation develops progressive weight gain, type 2 diabetes, and diabetic nephropathy that has many features of advanced human DN, including increased mesangial matrix, mesangiolysis, podocyte loss, and proteinuria. Selective antagonism of the endothelin-1 type A receptor (ETAR) by atrasentan treatment in combination with renin-angiotensin-aldosterone system inhibition with losartan has been shown to have the therapeutic benefit of lowering proteinuria in patients with DN, but the underlying mechanism for this benefit is not well understood. Using a similar therapeutic approach in diabetic BTBR ob/ob mice, this treatment regimen significantly increased glomerular podocyte number compared with diabetic BTBR ob/ob controls and suggested that parietal epithelial cells were a source for podocyte restoration. Atrasentan treatment alone also increased podocyte number but to a lesser degree. Mice treated with atrasentan demonstrated a reduction in proteinuria, matching the functional improvement reported in humans. This is a first demonstration that treatment with the highly selective ETAR antagonist atrasentan can lead to restoration of the diminished podocyte number characteristic of DN in humans and thereby underlies the reduction in proteinuria in patients with diabetes undergoing similar treatment. The benefit of ETAR antagonism in DN extended to a decrease in mesangial matrix as measured by a reduction in accumulations of collagen type IV in both the atrasentan and atrasentan + losartan-treated groups compared with untreated controls.
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Affiliation(s)
- Kelly L Hudkins
- Department of Pathology, University of Washington, Seattle, Washington
| | - Tomasz A Wietecha
- Department of Pathology, University of Washington, Seattle, Washington
| | - Floor Steegh
- Department of Pathology, University of Washington, Seattle, Washington
| | - Charles E Alpers
- Department of Pathology, University of Washington, Seattle, Washington
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Atchison DK, O'Connor CL, Menon R, Otto EA, Ganesh SK, Wiggins RC, Smrcka AV, Bitzer M. Hypertension induces glomerulosclerosis in phospholipase C-ε1 deficiency. Am J Physiol Renal Physiol 2020; 318:F1177-F1187. [PMID: 32223311 DOI: 10.1152/ajprenal.00541.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Loss-of-function mutations in phospholipase C-ε1 (PLCE1) have been detected in patients with nephrotic syndrome, but other family members with the same mutation were asymptomatic, suggesting additional stressor are required to cause the full phenotype. Consistent with these observations, we determined that global Plce1-deficient mice have histologically normal glomeruli and no albuminuria at baseline. Angiotensin II (ANG II) is known to induce glomerular damage in genetically susceptible individuals. Therefore, we tested whether ANG II enhances glomerular damage in Plce1-deficient mice. ANG II increased blood pressure equally in Plce1-deficient and wild-type littermates. Additionally, it led to 20-fold increased albuminuria and significantly more sclerotic glomeruli in Plce1-deficient mice compared with wild-type littermates. Furthermore, Plce1-deficient mice demonstrated diffuse mesangial expansion, podocyte loss, and focal podocyte foot process effacement. To determine whether these effects are mediated by hypertension and hyperfiltration, rather than directly through ANG II, we raised blood pressure to a similar level using DOCA + salt + uninephrectomy and norepinephrine. This caused a fivefold increase in albuminuria in Plce1-deficient mice and a significant increase in the number of sclerotic glomeruli. Consistent with previous findings in mice, we detected strong PLCE1 transcript expression in podocytes using single cell sequencing of human kidney tissue. In hemagglutinin-tagged Plce1 transgenic mice, Plce1 was detected in podocytes and also in glomerular arterioles using immunohistochemistry. Our data demonstrate that Plce1 deficiency in mice predisposes to glomerular damage secondary to hypertensive insults.
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Affiliation(s)
- Douglas K Atchison
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Christopher L O'Connor
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Rajasree Menon
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Edgar A Otto
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Santhi K Ganesh
- Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Roger C Wiggins
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Alan V Smrcka
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
| | - Markus Bitzer
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
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48
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Matsuda J, Maier M, Aoudjit L, Baldwin C, Takano T. ARHGEF7 ( β-PIX) Is Required for the Maintenance of Podocyte Architecture and Glomerular Function. J Am Soc Nephrol 2020; 31:996-1008. [PMID: 32188698 DOI: 10.1681/asn.2019090982] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 02/09/2020] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Previous studies showed that Cdc42, a member of the prototypical Rho family of small GTPases and a regulator of the actin cytoskeleton, is critical for the normal development and health of podocytes. However, upstream regulatory mechanisms for Cdc42 activity in podocytes are largely unknown. METHODS We used a proximity-based ligation assay, BioID, to identify guanine nucleotide exchange factors that activate Cdc42 in immortalized human podocytes. We generated podocyte-specific ARHGEF7 (commonly known as β-PIX) knockout mice by crossing β-PIX floxed mice with Podocin-Cre mice. Using shRNA, we established cultured mouse podocytes with β-PIX knockdown and their controls. RESULTS We identified β-PIX as a predominant guanine nucleotide exchange factor that interacts with Cdc42 in human podocytes. Podocyte-specific β-PIX knockout mice developed progressive proteinuria and kidney failure with global or segmental glomerulosclerosis in adulthood. Glomerular podocyte density gradually decreased in podocyte-specific β-PIX knockout mice, indicating podocyte loss. Compared with controls, glomeruli from podocyte-specific β-PIX knockout mice and cultured mouse podocytes with β-PIX knockdown exhibited significant reduction in Cdc42 activity. Loss of β-PIX promoted podocyte apoptosis, which was mediated by the reduced activity of the prosurvival transcriptional regulator Yes-associated protein. CONCLUSIONS These findings indicate that β-PIX is required for the maintenance of podocyte architecture and glomerular function via Cdc42 and its downstream Yes-associated protein activities. This appears to be the first evidence that a Rho-guanine nucleotide exchange factor plays a critical role in podocytes.
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Affiliation(s)
- Jun Matsuda
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Mirela Maier
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Lamine Aoudjit
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Cindy Baldwin
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Tomoko Takano
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada
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Sutherland MR, Vojisavljevic D, Black MJ. A practical guide to the stereological assessment of glomerular number, size, and cellular composition. Anat Rec (Hoboken) 2020; 303:2679-2692. [PMID: 31960613 DOI: 10.1002/ar.24361] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 11/15/2019] [Accepted: 11/22/2019] [Indexed: 12/13/2022]
Abstract
The evaluation of a range of measures in the kidneys, such as developmental stage, rate and success, injury, and disease processes, relies on obtaining information on the three-dimensional structure of the renal corpuscles, and in particular the glomerular capillary tufts. To do this in the most accurate, comprehensive, and unbiased manner depends on a knowledge of stereological methods. In this article, we provide a practical guide for researchers on how to quantitate a number of structures in the kidneys, including the estimation of total glomerular number, glomerular capillary length and filtration surface area, and the cellular composition of individual glomeruli. Guidance is also provided on how to apply these methods to kidneys at different sizes and levels of maturity.
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Affiliation(s)
- Megan R Sutherland
- Biomedicine Discovery Institute and the Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
| | - Danica Vojisavljevic
- Biomedicine Discovery Institute and the Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
| | - Mary Jane Black
- Biomedicine Discovery Institute and the Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
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50
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Minakawa A, Fukuda A, Sato Y, Kikuchi M, Kitamura K, Wiggins RC, Fujimoto S. Podocyte hypertrophic stress and detachment precedes hyperglycemia or albuminuria in a rat model of obesity and type2 diabetes-associated nephropathy. Sci Rep 2019; 9:18485. [PMID: 31811176 PMCID: PMC6898392 DOI: 10.1038/s41598-019-54692-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/16/2019] [Indexed: 02/06/2023] Open
Abstract
Type2 diabetes-associated nephropathy is the commonest cause of renal failure. Mechanisms responsible are controversial. Leptin-deficient hyperphagic Zucker (fa/fa) rats were modeled to test the hypothesis that glomerular enlargement drives podocyte hypertrophic stress leading to accelerated podocyte detachment, podocyte depletion, albuminuria and progression. By 6weeks, prior to development of either hyperglycemia or albuminuria, fa/fa rats were hyperinsulinemic with high urinary IGF1/2 excretion, gaining weight rapidly, and had 1.6-fold greater glomerular volume than controls (P < 0.01). At this time the podocyte number per glomerulus was not yet reduced although podocytes were already hypertrophically stressed as shown by high podocyte phosphor-ribosomal S6 (a marker of mTORC1 activation), high urinary pellet podocin:nephrin mRNA ratio and accelerated podocyte detachment (high urinary pellet podocin:aquaporin2 mRNA ratio). Subsequently, fa/fa rats became both hyperglycemic and albuminuric. 24 hr urine albumin excretion correlated highly with decreasing podocyte density (R2 = 0.86), as a consequence of both increasing glomerular volume (R2 = 0.70) and decreasing podocyte number (R2 = 0.63). Glomerular podocyte loss rate was quantitatively related to podocyte detachment rate measured by urine pellet mRNAs. Glomerulosclerosis occurred when podocyte density reached <50/106um3. Reducing food intake by 40% to slow growth reduced podocyte hypertrophic stress and "froze" all elements of the progression process in place, but had small effect on hyperglycemia. Glomerular enlargement caused by high growth factor milieu starting in pre-diabetic kidneys appears to be a primary driver of albuminuria in fa/fa rats and thereby an under-recognized target for progression prevention. Progression risk could be identified prior to onset of hyperglycemia or albuminuria, and monitored non-invasively by urinary pellet podocyte mRNA markers.
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Affiliation(s)
- Akihiro Minakawa
- Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
- First Department of Internal Medicine, University of Miyazaki, Miyazaki, Japan
| | - Akihiro Fukuda
- Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
- Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Yufu, Japan.
| | - Yuji Sato
- Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Masao Kikuchi
- Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
- First Department of Internal Medicine, University of Miyazaki, Miyazaki, Japan
| | - Kazuo Kitamura
- First Department of Internal Medicine, University of Miyazaki, Miyazaki, Japan
| | - Roger C Wiggins
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Shouichi Fujimoto
- Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
- Department of Hemovascular Medicine and Artificial Organs, University of Miyazaki, Miyazaki, Japan
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