1
|
Vishy CE, Thomas C, Vincent T, Crawford DK, Goddeeris MM, Freedman BS. Genetics of cystogenesis in base-edited human organoids reveal therapeutic strategies for polycystic kidney disease. Cell Stem Cell 2024; 31:537-553.e5. [PMID: 38579684 DOI: 10.1016/j.stem.2024.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 12/19/2023] [Accepted: 03/08/2024] [Indexed: 04/07/2024]
Abstract
In polycystic kidney disease (PKD), microscopic tubules expand into macroscopic cysts. Among the world's most common genetic disorders, PKD is inherited via heterozygous loss-of-function mutations but is theorized to require additional loss of function. To test this, we establish human pluripotent stem cells in allelic series representing four common nonsense mutations, using CRISPR base editing. When differentiated into kidney organoids, homozygous mutants spontaneously form cysts, whereas heterozygous mutants (original or base corrected) express no phenotype. Using these, we identify eukaryotic ribosomal selective glycosides (ERSGs) as PKD therapeutics enabling ribosomal readthrough of these same nonsense mutations. Two different ERSGs not only prevent cyst initiation but also limit growth of pre-formed cysts by partially restoring polycystin expression. Furthermore, glycosides accumulate in cyst epithelia in organoids and mice. Our findings define the human polycystin threshold as a surmountable drug target for pharmacological or gene therapy interventions, with relevance for understanding disease mechanisms and future clinical trials.
Collapse
Affiliation(s)
- Courtney E Vishy
- Division of Nephrology, Department of Medicine, Institute for Stem Cell and Regenerative Medicine, and Kidney Research Institute, University of Washington, Seattle, WA 98109, USA
| | - Chardai Thomas
- Division of Nephrology, Department of Medicine, Institute for Stem Cell and Regenerative Medicine, and Kidney Research Institute, University of Washington, Seattle, WA 98109, USA
| | - Thomas Vincent
- Division of Nephrology, Department of Medicine, Institute for Stem Cell and Regenerative Medicine, and Kidney Research Institute, University of Washington, Seattle, WA 98109, USA
| | - Daniel K Crawford
- Eloxx Pharmaceuticals, Inc., 950 Winter Street, Waltham, MA 02451, USA
| | | | - Benjamin S Freedman
- Division of Nephrology, Department of Medicine, Institute for Stem Cell and Regenerative Medicine, and Kidney Research Institute, University of Washington, Seattle, WA 98109, USA; Plurexa, 1209 6th Ave. N., Seattle, WA 98109, USA.
| |
Collapse
|
2
|
Haykir B, Moser SO, Pastor-Arroyo EM, Schnitzbauer U, Radvanyi Z, Prucker I, Qiu D, Fiedler D, Saiardi A, Jessen HJ, Hernando N, Wagner CA. The Ip6k1 and Ip6k2 Kinases Are Critical for Normal Renal Tubular Function. J Am Soc Nephrol 2024; 35:441-455. [PMID: 38317282 PMCID: PMC11000740 DOI: 10.1681/asn.0000000000000303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 12/24/2023] [Indexed: 02/07/2024] Open
Abstract
SIGNIFICANCE STATEMENT Kidneys are gatekeepers of systemic inorganic phosphate balance because they control urinary phosphate excretion. In yeast and plants, inositol hexakisphosphate kinases (IP6Ks) are central to regulate phosphate metabolism, whereas their role in mammalian phosphate homeostasis is mostly unknown. We demonstrate in a renal cell line and in mice that Ip6k1 and Ip6k2 are critical for normal expression and function of the major renal Na + /Pi transporters NaPi-IIa and NaPi-IIc. Moreover, Ip6k1/2-/- mice also show symptoms of more generalized kidney dysfunction. Thus, our results suggest that IP6Ks are essential for phosphate metabolism and proper kidney function in mammals. BACKGROUND Inorganic phosphate is an essential mineral, and its plasma levels are tightly regulated. In mammals, kidneys are critical for maintaining phosphate homeostasis through mechanisms that ultimately regulate the expression of the Na + /Pi cotransporters NaPi-IIa and NaPi-IIc in proximal tubules. Inositol pyrophosphate 5-IP 7 , generated by IP6Ks, is a main regulator of phosphate metabolism in yeast and plants. IP6Ks are conserved in mammals, but their role in phosphate metabolism in vivo remains unexplored. METHODS We used in vitro (opossum kidney cells) and in vivo (renal tubular-specific Ip6k1/2-/- mice) models to analyze the role of IP6K1/2 in phosphate homeostasis in mammals. RESULTS In both systems, Ip6k1 and Ip6k2 are responsible for synthesis of 5-IP 7 . Depletion of Ip6k1/2 in vitro reduced phosphate transport and mRNA expression of Na + /Pi cotransporters, and it blunts phosphate transport adaptation to changes in ambient phosphate. Renal ablation of both kinases in mice also downregulates the expression of NaPi-IIa and NaPi-IIc and lowered the uptake of phosphate into proximal renal brush border membranes. In addition, the absence of Ip6k1 and Ip6k2 reduced the plasma concentration of fibroblast growth factor 23 and increased bone resorption, despite of which homozygous males develop hypophosphatemia. Ip6k1/2-/- mice also show increased diuresis, albuminuria, and hypercalciuria, although the morphology of glomeruli and proximal brush border membrane seemed unaffected. CONCLUSIONS Depletion of renal Ip6k1/2 in mice not only altered phosphate homeostasis but also dysregulated other kidney functions.
Collapse
Affiliation(s)
- Betül Haykir
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Seraina Olivia Moser
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Eva Maria Pastor-Arroyo
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Udo Schnitzbauer
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Zsuzsa Radvanyi
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Isabel Prucker
- The Center for Integrative Biological Signalling Studies, Institute of Organic Chemistry and CIBSS, University of Freiburg, Freiburg, Germany
| | - Danye Qiu
- The Center for Integrative Biological Signalling Studies, Institute of Organic Chemistry and CIBSS, University of Freiburg, Freiburg, Germany
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Henning J. Jessen
- The Center for Integrative Biological Signalling Studies, Institute of Organic Chemistry and CIBSS, University of Freiburg, Freiburg, Germany
| | - Nati Hernando
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Carsten A. Wagner
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| |
Collapse
|
3
|
Pfeffer T, Krug SM, Kracke T, Schürfeld R, Colbatzky F, Kirschner P, Medert R, Freichel M, Schumacher D, Bartosova M, Zarogiannis SG, Muckenthaler MU, Altamura S, Pezer S, Volk N, Schwab C, Duensing S, Fleming T, Heidenreich E, Zschocke J, Hell R, Poschet G, Schmitt CP, Peters V. Knock-out of dipeptidase CN2 in human proximal tubular cells disrupts dipeptide and amino acid homeostasis and para- and transcellular solute transport. Acta Physiol (Oxf) 2024; 240:e14126. [PMID: 38517248 DOI: 10.1111/apha.14126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 02/15/2024] [Accepted: 02/21/2024] [Indexed: 03/23/2024]
Abstract
AIM Although of potential biomedical relevance, dipeptide metabolism has hardly been studied. We found the dipeptidase carnosinase-2 (CN2) to be abundant in human proximal tubules, which regulate water and solute homeostasis. We therefore hypothesized, that CN2 has a key metabolic role, impacting proximal tubular transport function. METHODS A knockout of the CN2 gene (CNDP2-KO) was generated in human proximal tubule cells and characterized by metabolomics, RNA-seq analysis, paracellular permeability analysis and ion transport. RESULTS CNDP2-KO in human proximal tubule cells resulted in the accumulation of cellular dipeptides, reduction of amino acids and imbalance of related metabolic pathways, and of energy supply. RNA-seq analyses indicated altered protein metabolism and ion transport. Detailed functional studies demonstrated lower CNDP2-KO cell viability and proliferation, and altered ion and macromolecule transport via trans- and paracellular pathways. Regulatory and transport protein abundance was disturbed, either as a consequence of the metabolic imbalance or the resulting functional disequilibrium. CONCLUSION CN2 function has a major impact on intracellular amino acid and dipeptide metabolism and is essential for key metabolic and regulatory functions of proximal tubular cells. These findings deserve in vivo analysis of the relevance of CN2 for nephron function and regulation of body homeostasis.
Collapse
Affiliation(s)
- Tilman Pfeffer
- Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
- Tissue Bank of the German Center for Infection Research (DZIF), Partner Site Heidelberg, Institute of Pathology, Heidelberg University Hospital, Heidelberg, Germany
| | - Susanne M Krug
- Clinical Physiology/Nutritional Medicine, Charité-Universitätsmedizin Berlin, CBF, Berlin, Germany
| | - Tamara Kracke
- Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Robin Schürfeld
- Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Florian Colbatzky
- Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Philip Kirschner
- Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Rebekka Medert
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Dagmar Schumacher
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Maria Bartosova
- Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Sotiris G Zarogiannis
- Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Martina U Muckenthaler
- Department of Pediatric Oncology, Hematology and Immunology and Hopp Children Cancer Center (KiTZ), University Hospital Heidelberg, Heidelberg, Germany
- Molecular Medicine Partnership Unit (MMPU), EMBL and University of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Sandro Altamura
- Department of Pediatric Oncology, Hematology and Immunology and Hopp Children Cancer Center (KiTZ), University Hospital Heidelberg, Heidelberg, Germany
- Molecular Medicine Partnership Unit (MMPU), EMBL and University of Heidelberg, Heidelberg, Germany
| | - Silvia Pezer
- Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Nadine Volk
- Tissue Bank of the National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | - Constantin Schwab
- Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany
| | - Stefan Duensing
- Department of Urology, University Hospital Heidelberg and National Center for Tumor Diseases (NCT) Heidelberg, Heidelberg, Germany
| | - Thomas Fleming
- Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
| | - Elena Heidenreich
- Centre for Organismal Studies (COS), University of Heidelberg, Heidelberg, Germany
| | - Johannes Zschocke
- Institute of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Rüdiger Hell
- Centre for Organismal Studies (COS), University of Heidelberg, Heidelberg, Germany
| | - Gernot Poschet
- Centre for Organismal Studies (COS), University of Heidelberg, Heidelberg, Germany
| | - Claus P Schmitt
- Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Verena Peters
- Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| |
Collapse
|
4
|
Vallon V. How can inhibition of glucose and sodium transport in the early proximal tubule protect the cardiorenal system? Nephrol Dial Transplant 2024:gfae060. [PMID: 38439675 DOI: 10.1093/ndt/gfae060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024] Open
Abstract
What mechanisms can link the inhibition of SGLT2-mediated Na+-coupled glucose reabsorption in early proximal tubules to kidney and heart protection in patients with and without type 2 diabetes? Due to physical and functional coupling of SGLT2 to other sodium and metabolite transporters in the early proximal tubule (including NHE3, URAT1), inhibitors of SGLT2 (SGLT2i) reduce reabsorption not only of glucose, inducing osmotic diuresis, but of other metabolites plus of a larger amount of sodium than expected based on SGLT2 inhibition alone, thereby reducing volume retention, hypertension, and hyperuricemia. Metabolic adaptations to SGLT2i include a fasting-like response, with enhanced lipolysis and formation of ketone bodies that serve as additional fuel for kidneys and heart. Making use of the physiology of tubulo-glomerular communication, SGLT2i functionally lower glomerular capillary pressure and filtration rate, thereby reducing physical stress on the glomerular filtration barrier, tubular exposure to albumin and nephrotoxic compounds, and the oxygen demand for reabsorbing the filtered load. Together with reduced gluco-toxicity in the early proximal tubule and better distribution of transport work along the nephron, SGLT2i can preserve tubular integrity and transport function and, thereby, GFR in the long-term. By shifting transport downstream, SGLT2 inhibitors may simulate systemic hypoxia at the oxygen sensors in the deep cortex/outer medulla, which stimulates erythropoiesis and, together with osmotic diuresis, enhances hematocrit and thereby improves oxygen delivery to all organs. The described SGLT2-dependent effects may be complemented by off-target effects of SGLT2i on the heart itself and on the microbiome formation of cardiovascular-effective uremic toxins.
Collapse
Affiliation(s)
- Volker Vallon
- Division of Nephrology and Hypertension, Department of Medicine, University of California San Diego, La Jolla, CA, USA
- Department of Pharmacology, University of California San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, San Diego, CA, USA
| |
Collapse
|
5
|
Sugahara S, Brooks CR. Adenine Nucleotide Translocators Control Kidney Metabolism and Lipid Handling. J Am Soc Nephrol 2024; 35:257-258. [PMID: 38356156 PMCID: PMC10962857 DOI: 10.1681/asn.0000000000000314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024] Open
Affiliation(s)
- Sho Sugahara
- Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Craig R. Brooks
- Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
| |
Collapse
|
6
|
DiKun KM, Tang XH, Fu L, Choi ME, Lu C, Gudas LJ. Retinoic acid receptor α activity in proximal tubules prevents kidney injury and fibrosis. Proc Natl Acad Sci U S A 2024; 121:e2311803121. [PMID: 38330015 PMCID: PMC10873609 DOI: 10.1073/pnas.2311803121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 12/18/2023] [Indexed: 02/10/2024] Open
Abstract
Chronic kidney disease (CKD) is characterized by a gradual loss of kidney function and affects ~13.4% of the global population. Progressive tubulointerstitial fibrosis, driven in part by proximal tubule (PT) damage, is a hallmark of late stages of CKD and contributes to the development of kidney failure, for which there are limited treatment options. Normal kidney development requires signaling by vitamin A (retinol), which is metabolized to retinoic acid (RA), an endogenous agonist for the RA receptors (RARα, β, γ). RARα levels are decreased in a mouse model of diabetic nephropathy and restored with RA administration; additionally, RA treatment reduced fibrosis. We developed a mouse model in which a spatiotemporal (tamoxifen-inducible) deletion of RARα in kidney PT cells of adult mice causes mitochondrial dysfunction, massive PT injury, and apoptosis without the use of additional nephrotoxic substances. Long-term effects (3 to 4.5 mo) of RARα deletion include increased PT secretion of transforming growth factor β1, inflammation, interstitial fibrosis, and decreased kidney function, all of which are major features of human CKD. Therefore, RARα's actions in PTs are crucial for PT homeostasis, and loss of RARα causes injury and a key CKD phenotype.
Collapse
Affiliation(s)
- Krysta M. DiKun
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, New York, NY10065
- Weill Cornell Graduate School of Medical Sciences, New York, NY10065
| | - Xiao-Han Tang
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, New York, NY10065
| | - Leiping Fu
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, New York, NY10065
| | - Mary E. Choi
- New York Presbyterian Hospital, New York, NY10065
- Division of Nephrology and Hypertension, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, NY10065
| | | | - Lorraine J. Gudas
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, New York, NY10065
- Weill Cornell Graduate School of Medical Sciences, New York, NY10065
- Department of Urology, New York, NY10065
| |
Collapse
|
7
|
Hurtado KA, Schnellmann RG. Mitophagy regulates mitochondrial number following pharmacological induction of mitochondrial biogenesis in renal proximal tubule cells. Front Pharmacol 2024; 15:1344075. [PMID: 38375036 PMCID: PMC10875001 DOI: 10.3389/fphar.2024.1344075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 01/08/2024] [Indexed: 02/21/2024] Open
Abstract
Background: Mitochondrial biogenesis (MB) induction through the activation of the 5-Hydroxytriptamine (5-HT) 1F receptor (HTR1F) is a promising mechanism for the treatment of diseases characterized by mitochondrial dysfunction, such as acute kidney injury (AKI). While several studies report pharmacological activation of MB in the proximal tubule, it is unclear how the proximal tubule regulates itself once the pharmacological activation is removed. Mitophagy is the process of selective mitochondria degradation. We hypothesize that mitophagy decreases mitochondrial number after pharmacological stimulation and restore mitochondrial homeostasis. Methods: Renal proximal tubules were treated at time 0hr with LY344864 or vehicle for 24 h and then removed. LY344864, a selective HTR1F agonist, induces MB in renal proximal tubules as previously reported (Gibbs et al., Am J Physiol Renal Physiol, 2018, 314(2), F260-F268). Vehicle and pharmacological reagents were added at the 24 h time point. Electron microscopy was used to assess mitochondrial morphology, number, and autolysosomes. Seahorse Bioscience XF-96 extracellular flux analyzer was used to measure maximal mitochondrial oxygen consumption rates (FCCP-OCR), a functional marker of MB. Results: LY344864 treatment increased FCCP-OCR, phosphorylation of protein kinase B (AKT), peroxisome proliferator-activated receptor γ coactivator-1alpha (PGC-1α), and mitochondrial number after 24 h. These endpoints decreased to baseline 24 h after LY344864 removal. Treatment with ROC-325, an autophagy inhibitor, increased Sequestosome-1 (SQSTM1/P62) and microtubule-associated protein-1 light chain 3 (LC3B) after 24 h of treatment. Also, ROC-325 treatment sustained the elevated mitochondrial number after LY344864 pre-treatment and removal. Conclusion: These data revealed that inhibition of autophagy extends elevated mitochondrial number and function by preventing the lysosomal degradation of mitochondria after the removal of LY344864.
Collapse
Affiliation(s)
- Kevin A. Hurtado
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ, United States
| | - Rick G. Schnellmann
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ, United States
- Southern Arizona VA Health Care System, Tucson, AZ, United States
- Southwest Environmental Health Science Center, University of Arizona, Tucson, AZ, United States
| |
Collapse
|
8
|
Oe Y, Kim YC, Sidorenko VS, Zhang H, Kanoo S, Lopez N, Goodluck HA, Crespo-Masip M, Vallon V. SGLT2 inhibitor dapagliflozin protects the kidney in a murine model of Balkan nephropathy. Am J Physiol Renal Physiol 2024; 326:F227-F240. [PMID: 38031729 DOI: 10.1152/ajprenal.00228.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 11/06/2023] [Accepted: 11/27/2023] [Indexed: 12/01/2023] Open
Abstract
Proximal tubular uptake of aristolochic acid (AA) forms aristolactam (AL)-DNA adducts, which cause a p53/p21-mediated DNA damage response and acute tubular injury. Recurrent AA exposure causes kidney function loss and fibrosis in humans (Balkan endemic nephropathy) and mice and is a model of (acute kidney injury) AKI to chronic kidney disease (CKD) transition. Inhibitors of the proximal tubule sodium-glucose transporter SGLT2 can protect against CKD progression, but their effect on AA-induced kidney injury remains unknown. C57BL/6J mice (15-wk-old) were administered vehicle or AA every 3 days for 3 wk (10 and 3 mg/kg ip in females and males, respectively). Dapagliflozin (dapa, 0.01 g/kg diet) or vehicle was initiated 7 days prior to AA injections. All dapa effects were sex independent, including a robust glycosuria. Dapa lowered urinary kidney-injury molecule 1 (KIM-1) and albumin (both normalized to creatinine) after the last AA injection and kidney mRNA expression of early DNA damage response markers (p53 and p21) 3 wk later at the study end. Dapa also attenuated AA-induced increases in plasma creatinine as well as AA-induced up-regulation of renal pro-senescence, pro-inflammatory and pro-fibrotic genes, and kidney collagen staining. When assessed 1 day after a single AA injection, dapa pretreatment attenuated AL-DNA adduct formation by 10 and 20% in kidney and liver, respectively, associated with reduced p21 expression. Initiating dapa application after the last AA injection also improved kidney outcome but in a less robust manner. In conclusion, the first evidence is presented that pretreatment with an SGLT2 inhibitor can attenuate the AA-induced DNA damage response and subsequent nephropathy.NEW & NOTEWORTHY Recurrent exposure to aristolochic acid (AA) causes kidney function loss and fibrosis in mice and in humans, e.g., in the form of the endemic Balkan nephropathy. Inhibitors of the proximal tubule sodium-glucose transporter SGLT2 can protect against CKD progression, but their effect on AA-induced kidney injury remains unknown. Here we provide the first evidence in a murine model that pretreatment with an SGLT2 inhibitor can attenuate the AA-induced DNA damage response and subsequent nephropathy.
Collapse
Affiliation(s)
- Yuji Oe
- Department of Medicine, University of California-San Diego, La Jolla, California, United States
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| | - Young Chul Kim
- Department of Medicine, University of California-San Diego, La Jolla, California, United States
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| | - Viktoriya S Sidorenko
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, United States
| | - Haiyan Zhang
- Department of Pathology, University of California-San Diego, San Diego, California, United States
| | - Sadhana Kanoo
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| | - Natalia Lopez
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| | - Helen A Goodluck
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| | - Maria Crespo-Masip
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| | - Volker Vallon
- Department of Medicine, University of California-San Diego, La Jolla, California, United States
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| |
Collapse
|
9
|
Houillier P. Sweet phosphate in the proximal tubule. Kidney Int 2024; 105:235-237. [PMID: 38245211 DOI: 10.1016/j.kint.2023.07.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 07/24/2023] [Indexed: 01/22/2024]
Affiliation(s)
- Pascal Houillier
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université Paris Cité, Paris, France; CNRS ERL 8228-Laboratoire de Physiologie Rénale et Tubulopathies, Paris, France; Service de Physiologie, Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Paris, France; Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Paris, France; Centre de Référence des Maladies Rares du Calcium et du Phosphate, Paris, France.
| |
Collapse
|
10
|
Beamish JA, Telang AC, McElliott MC, Al-Suraimi A, Chowdhury M, Ference-Salo JT, Otto EA, Menon R, Soofi A, Weinberg JM, Patel SR, Dressler GR. Pax protein depletion in proximal tubules triggers conserved mechanisms of resistance to acute ischemic kidney injury preventing transition to chronic kidney disease. Kidney Int 2024; 105:312-327. [PMID: 37977366 PMCID: PMC10958455 DOI: 10.1016/j.kint.2023.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 09/18/2023] [Accepted: 10/25/2023] [Indexed: 11/19/2023]
Abstract
Acute kidney injury (AKI) is a common condition that lacks effective treatments. In part, this shortcoming is due to an incomplete understanding of the genetic mechanisms that control pathogenesis and recovery. Identifying the molecular and genetic regulators unique to nephron segments that dictate vulnerability to injury and regenerative potential could lead to new therapeutic targets to treat ischemic kidney injury. Pax2 and Pax8 are homologous transcription factors with overlapping functions that are critical for kidney development and are re-activated in AKI. Here, we examined the role of Pax2 and Pax8 in recovery from ischemic AKI and found them upregulated after severe AKI and correlated with chronic injury. Surprisingly, proximal-tubule-selective deletion of Pax2 and Pax8 resulted in a less severe chronic injury phenotype. This effect was mediated by protection against the acute insult, similar to pre-conditioning. Prior to injury, Pax2 and Pax8 mutant mice develop a unique subpopulation of proximal tubule cells in the S3 segment that displayed features usually seen only in acute or chronic injury. The expression signature of these cells was strongly enriched with genes associated with other mechanisms of protection against ischemic AKI including caloric restriction, hypoxic pre-conditioning, and female sex. Thus, our results identified a novel role for Pax2 and Pax8 in mature proximal tubules that regulates critical genes and pathways involved in both the injury response and protection from ischemic AKI.
Collapse
Affiliation(s)
- Jeffrey A Beamish
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA.
| | - Asha C Telang
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Madison C McElliott
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Anas Al-Suraimi
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Mahboob Chowdhury
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Jenna T Ference-Salo
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Edgar A Otto
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Rajasree Menon
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Abdul Soofi
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
| | - Joel M Weinberg
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Sanjeevkumar R Patel
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Gregory R Dressler
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA
| |
Collapse
|
11
|
Shaughnessey EM, Kann SH, Charest JL, Vedula EM. Human Kidney Proximal Tubule-Microvascular Model Facilitates High-Throughput Analyses of Structural and Functional Effects of Ischemia-Reperfusion Injury. Adv Biol (Weinh) 2024; 8:e2300127. [PMID: 37786311 DOI: 10.1002/adbi.202300127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 08/27/2023] [Indexed: 10/04/2023]
Abstract
Kidney ischemia reperfusion injury (IRI) poses a major global healthcare burden, but effective treatments remain elusive. IRI involves a complex interplay of tissue-level structural and functional changes caused by interruptions in blood and filtrate flow and reduced oxygenation. Existing in vitro models poorly replicate the in vivo injury environment and lack means of monitoring tissue function during the injury process. Here, a high-throughput human primary kidney proximal tubule (PT)-microvascular model is described, which facilitates in-depth structural and rapid functional characterization of IRI-induced changes in the tissue barrier. The PREDICT96 (P96) microfluidic platform's user-controlled fluid flow can mimic the conditions of IR to induce pronounced changes in cell structure that resemble clinical and in vivo phenotypes. High-throughput trans-epi/endo-thelial electrical resistance (TEER) sensing is applied to non-invasively track functional changes in the PT-microvascular barrier during the two-stage injury process and over repeated episodes of injury. Notably, ischemia causes an initial increase in tissue TEER followed by a sudden increase in permeability upon reperfusion, and this biphasic response occurs only with the loss of both fluid flow and oxygenation. This study demonstrates the potential of the P96 kidney IRI model to enhance understanding of IRI and fuel therapeutic development.
Collapse
Affiliation(s)
- Erin M Shaughnessey
- Draper Scholar, The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Samuel H Kann
- Draper Scholar, The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
- Department of Mechanical Engineering, Boston University, 110 Cummington Mall, Boston, MA, 02215, USA
| | - Joseph L Charest
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
| | - Else M Vedula
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
| |
Collapse
|
12
|
Keller S, Luciani A, Devuyst O. The structure of megalin: shedding new light on receptor-mediated endocytosis. Kidney Int 2024; 105:11-14. [PMID: 37380129 DOI: 10.1016/j.kint.2023.05.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/22/2023] [Indexed: 06/30/2023]
Affiliation(s)
- Svenja Keller
- Institute of Physiology, Zurich Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Alessandro Luciani
- Institute of Physiology, Zurich Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Olivier Devuyst
- Institute of Physiology, Zurich Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland; Institute for Rare Diseases, Cliniques universitaires Saint-Luc, UCLouvain, Brussels, Belgium.
| |
Collapse
|
13
|
Rana R, Manoharan J, Elwakiel A, Zimmermann S, Lindquist JA, Gupta D, Al-Dabet MM, Gadi I, Fallmann J, Singh K, Gupta A, Biemann R, Brandt S, Alo B, Kluge P, Garde R, Lamers C, Shahzad K, Künze G, Kohli S, Mertens PR, Isermann B. Glomerular-tubular crosstalk via cold shock Y-box binding protein-1 in the kidney. Kidney Int 2024; 105:65-83. [PMID: 37774921 DOI: 10.1016/j.kint.2023.09.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 08/02/2023] [Accepted: 09/01/2023] [Indexed: 10/01/2023]
Abstract
Glomerular-tubular crosstalk within the kidney has been proposed, but the paracrine signals enabling this remain largely unknown. The cold-shock protein Y-box binding protein 1 (YBX1) is known to regulate inflammation and kidney diseases but its role in podocytes remains undetermined. Therefore, we analyzed mice with podocyte specific Ybx1 deletion (Ybx1ΔPod). Albuminuria was increased in unchallenged Ybx1ΔPod mice, which surprisingly was associated with reduced glomerular, but enhanced tubular damage. Tubular toll-like receptor 4 (TLR4) expression, node-like receptor protein 3 (NLRP3) inflammasome activation and kidney inflammatory cell infiltrates were all increased in Ybx1ΔPod mice. In vitro, extracellular YBX1 inhibited NLRP3 inflammasome activation in tubular cells. Co-immunoprecipitation, immunohistochemical analyses, microscale cell-free thermophoresis assays, and blunting of the YBX1-mediated TLR4-inhibition by a unique YBX1-derived decapeptide suggests a direct interaction of YBX1 and TLR4. Since YBX1 can be secreted upon post-translational acetylation, we hypothesized that YBX1 secreted from podocytes can inhibit TLR4 signaling in tubular cells. Indeed, mice expressing a non-secreted YBX1 variant specifically in podocytes (Ybx1PodK2A mice) phenocopied Ybx1ΔPod mice, demonstrating a tubular-protective effect of YBX1 secreted from podocytes. Lipopolysaccharide-induced tubular injury was aggravated in Ybx1ΔPod and Ybx1PodK2A mice, indicating a pathophysiological relevance of this glomerular-tubular crosstalk. Thus, our data show that YBX1 is physiologically secreted from podocytes, thereby negatively modulating sterile inflammation in the tubular compartment, apparently by binding to and inhibiting tubular TLR4 signaling. Hence, we have uncovered an YBX1-dependent molecular mechanism of glomerular-tubular crosstalk.
Collapse
Affiliation(s)
- Rajiv Rana
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Jayakumar Manoharan
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Ahmed Elwakiel
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Silke Zimmermann
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Jonathan A Lindquist
- Clinic of Nephrology and Hypertension, Diabetes and Endocrinology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Dheerendra Gupta
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Moh'd Mohanad Al-Dabet
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany; Department of Medical Laboratories, Faculty of Health Sciences, American University of Madaba, Amman, Jordan
| | - Ihsan Gadi
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Jörg Fallmann
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Centre for Bioinformatics, Leipzig University, Leipzig, Germany
| | - Kunal Singh
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Anubhuti Gupta
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Ronald Biemann
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Sabine Brandt
- Clinic of Nephrology and Hypertension, Diabetes and Endocrinology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Bekas Alo
- Institute for Drug Discovery, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Paul Kluge
- Institute for Drug Discovery, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Ravindra Garde
- Institute for Drug Discovery, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Christina Lamers
- Institute for Drug Discovery, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Khurrum Shahzad
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Georg Künze
- Institute for Drug Discovery, Faculty of Medicine, Leipzig University, Leipzig, Germany; Center for Scalable Data Analytics and Artificial Intelligence, Leipzig University, Leipzig, Germany
| | - Shrey Kohli
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Peter R Mertens
- Clinic of Nephrology and Hypertension, Diabetes and Endocrinology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Berend Isermann
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany.
| |
Collapse
|
14
|
Denic A, Fnu A, Mahesh K, Rule AD. Authors' Reply: Morphometric Approach to Different Nephron Segments. J Am Soc Nephrol 2023; 34:2054-2056. [PMID: 38039092 PMCID: PMC10881185 DOI: 10.1681/asn.0000000000000234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2023] Open
Affiliation(s)
- Aleksandar Denic
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Aperna Fnu
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Kumar Mahesh
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Andrew D. Rule
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
- Division of Epidemiology, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
15
|
Yamamoto T, Isaka Y. Dietary Omega-3 Polyunsaturated Fatty Acids and Amelioration of CKD: Possible Cellular Mechanisms. Kidney360 2023; 4:1661-1662. [PMID: 38153790 PMCID: PMC10758506 DOI: 10.34067/kid.0000000000000252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 08/21/2023] [Indexed: 12/30/2023]
Affiliation(s)
- Takeshi Yamamoto
- Department of Nephrology, Osaka University Graduate School of Medicine, Osaka, Japan
| | | |
Collapse
|
16
|
Xiong L, Liu J, Han SY, Koppitch K, Guo JJ, Rommelfanger M, Miao Z, Gao F, Hallgrimsdottir IB, Pachter L, Kim J, MacLean AL, McMahon AP. Direct androgen receptor control of sexually dimorphic gene expression in the mammalian kidney. Dev Cell 2023; 58:2338-2358.e5. [PMID: 37673062 PMCID: PMC10873092 DOI: 10.1016/j.devcel.2023.08.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/20/2023] [Accepted: 08/04/2023] [Indexed: 09/08/2023]
Abstract
Mammalian organs exhibit distinct physiology, disease susceptibility, and injury responses between the sexes. In the mouse kidney, sexually dimorphic gene activity maps predominantly to proximal tubule (PT) segments. Bulk RNA sequencing (RNA-seq) data demonstrated that sex differences were established from 4 and 8 weeks after birth under gonadal control. Hormone injection studies and genetic removal of androgen and estrogen receptors demonstrated androgen receptor (AR)-mediated regulation of gene activity in PT cells as the regulatory mechanism. Interestingly, caloric restriction feminizes the male kidney. Single-nuclear multiomic analysis identified putative cis-regulatory regions and cooperating factors mediating PT responses to AR activity in the mouse kidney. In the human kidney, a limited set of genes showed conserved sex-linked regulation, whereas analysis of the mouse liver underscored organ-specific differences in the regulation of sexually dimorphic gene expression. These findings raise interesting questions on the evolution, physiological significance, disease, and metabolic linkage of sexually dimorphic gene activity.
Collapse
Affiliation(s)
- Lingyun Xiong
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA; Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Jing Liu
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Seung Yub Han
- Graduate Program in Genomics and Computational Biology, Biomedical Graduate Studies, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kari Koppitch
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Jin-Jin Guo
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Megan Rommelfanger
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Zhen Miao
- Graduate Program in Genomics and Computational Biology, Biomedical Graduate Studies, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Fan Gao
- Caltech Bioinformatics Resource Center at Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA
| | - Ingileif B Hallgrimsdottir
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Lior Pachter
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Department of Computing and Mathematical Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Junhyong Kim
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Adam L MacLean
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Andrew P McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA.
| |
Collapse
|
17
|
Barata R, Fila M, Dalla-Vale F, Bogarin R, Nunes P, Ramalho J, Rueff J, Calado J. Performance of the ACMG-AMP criteria in a large familial renal glucosuria cohort with identified SLC5A2 sequence variants. Clin Genet 2023; 104:582-586. [PMID: 37349938 DOI: 10.1111/cge.14395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 06/06/2023] [Accepted: 06/10/2023] [Indexed: 06/24/2023]
Abstract
Familial Renal Glucosuria (FRG) is a co-dominantly inherited trait characterized by orthoglycaemic glucosuria. From 2003 to 2015 we have reported several cohorts validating SLC5A2 (16p11.2), encoding SGLT2 (Na+/glucose cotransporter family member 2), as the gene responsible for FRG. The aim of this work was to validate the variants identified in our extended FRG cohort of published, as well more recent unreported cases, according to the ACMG-AMP 2015 criteria. Forty-six variants were evaluated, including 16 novel alleles first described in this study. All are rare, ultra-rare or absent from population databases and most are missense changes. According to the ACMG-AMP standards, only 74% of the variants were classified as P/LP. The lack of descriptions of unrelated patients with similar variants or failing to test additional affected family members, averted a conclusion for pathogenicity in the alleles that scored VUS, highlighting the importance of both family testing and variant reporting. Finally, the cryo-EM structure of the hSGLT2-MAP17 complex in the empagliflozin-bound state improved the ACMG-AMP pathogenicity score by identifying critical/functional protein domains.
Collapse
Affiliation(s)
- Rui Barata
- Department of Nephrology, Centro Hospitalar Lisboa Central, Lisbon, Portugal
| | - Marc Fila
- IGF UMR5203 CNRS INSERM U1191, Montpellier, France
- Department of Pediatric Nephrology, Centre Hospitalier Universitaire de Montpellier, Montpellier, France
| | - Fabienne Dalla-Vale
- Department of Pediatric Nephrology, Centre Hospitalier Universitaire de Montpellier, Montpellier, France
| | - Roberto Bogarin
- Department of Pediatrics, Hospital Nacional de Ninos, San José, Costa Rica
| | - Paula Nunes
- Department of Pediatrics, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal
| | - José Ramalho
- iNOVA4Health, NOVA Medical School, Universidade Nova de Lisboa, Lisbon, Portugal
| | - José Rueff
- ToxOmics, NOVA Medical School, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Joaquim Calado
- Department of Nephrology, Centro Hospitalar Lisboa Central, Lisbon, Portugal
- ToxOmics, NOVA Medical School, Universidade Nova de Lisboa, Lisbon, Portugal
| |
Collapse
|
18
|
Zhu M, He J, Xu Y, Zuo Y, Zhou W, Yue Z, Shao X, Cheng J, Wang T, Mou S. AMPK activation coupling SENP1-Sirt3 axis protects against acute kidney injury. Mol Ther 2023; 31:3052-3066. [PMID: 37608549 PMCID: PMC10556228 DOI: 10.1016/j.ymthe.2023.08.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 07/24/2023] [Accepted: 08/18/2023] [Indexed: 08/24/2023] Open
Abstract
Acute kidney injury (AKI) is a critical clinical condition that causes kidney fibrosis, and it currently lacks specific treatment options. In this research, we investigate the role of the SENP1-Sirt3 signaling pathway and its correlation with mitochondrial dysfunction in proximal tubular epithelial cells (PTECs) using folic acid (FA) and ischemia-reperfusion-induced (IRI) AKI models. Our findings reveal that Sirt3 SUMOylation site mutation (Sirt3 KR) or pharmacological stimulation (metformin) protected mice against AKI and subsequent kidney inflammation and fibrosis by decreasing the acetylation level of mitochondrial SOD2, reducing mitochondrial reactive oxygen species (mtROS), and subsequently restoring mitochondrial ATP level, reversing mitochondrial morphology and alleviating cell apoptosis. In addition, AKI in mice was similarly alleviated by reducing mtROS levels using N-acetyl-L-cysteine (NAC) or MitoQ. Metabolomics analysis further demonstrated an increase in antioxidants and metabolic shifts in Sirt3 KR mice during AKI, compared with Sirt3 wild-type (WT) mice. Activation of the AMPK pathway using metformin promoted the SENP1-Sirt3 axis and protected PTECs from apoptosis. Hence, the augmented deSUMOylation of Sirt3 in mitochondria, activated through the metabolism-related AMPK pathway, protects against AKI and subsequently mitigated renal inflammation and fibrosis through Sirt3-SOD2-mtROS, which represents a potential therapeutic target for AKI.
Collapse
Affiliation(s)
- Minyan Zhu
- Department of Nephrology, Molecular Cell Lab for Kidney Disease, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 201207, China
| | - Jianli He
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yao Xu
- Department of Nephrology, Molecular Cell Lab for Kidney Disease, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 201207, China
| | - Yong Zuo
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Wenyan Zhou
- Department of Nephrology, Molecular Cell Lab for Kidney Disease, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 201207, China
| | - Zhiying Yue
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xinghua Shao
- Department of Nephrology, Molecular Cell Lab for Kidney Disease, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 201207, China
| | - Jinke Cheng
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Tianshi Wang
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
| | - Shan Mou
- Department of Nephrology, Molecular Cell Lab for Kidney Disease, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 201207, China.
| |
Collapse
|
19
|
Yoshikawa T, Oguchi A, Toriu N, Sato Y, Kobayashi T, Ogawa O, Haga H, Sakurai S, Yamamoto T, Murakawa Y, Yanagita M. Tertiary Lymphoid Tissues Are Microenvironments with Intensive Interactions between Immune Cells and Proinflammatory Parenchymal Cells in Aged Kidneys. J Am Soc Nephrol 2023; 34:1687-1708. [PMID: 37548710 PMCID: PMC10561819 DOI: 10.1681/asn.0000000000000202] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 07/10/2023] [Indexed: 08/08/2023] Open
Abstract
SIGNIFICANCE STATEMENT Ectopic lymphoid structures called tertiary lymphoid tissues (TLTs) develop in several kidney diseases and are associated with poor renal prognosis. However, the mechanisms underlying TLT expansion and their effect on renal regeneration remain unclear. The authors report that single-nucleus RNA sequencing and validation experiments demonstrate that TLTs potentially amplify inflammation in aged injured kidneys. Lymphocytes within TLTs promote proinflammatory phenotypes of the surrounding proximal tubules and fibroblasts within the TLTs via proinflammatory cytokine production. These proinflammatory parenchymal cells then interact with immune cells by chemokine or cytokine production. Such cell-cell interactions potentially increase inflammation, expand TLTs, and exacerbate kidney injury. These findings help illuminate renal TLT pathology and suggest potential therapeutic targets. BACKGROUND Ectopic lymphoid structures called tertiary lymphoid tissues (TLTs) develop in several kidney diseases and are associated with poor renal prognosis. However, the mechanisms that expand TLTs and underlie exacerbation of kidney injury remain unclear. METHODS We performed single-nucleus RNA sequencing (snRNA-seq) on aged mouse kidneys with TLTs after ischemia-reperfusion injury. The results were validated using immunostaining, in situ hybridization of murine and human kidneys, and in vitro experiments. RESULTS Using snRNA-seq, we identified proinflammatory and profibrotic Vcam1+ injured proximal tubules (PTs) with NF κ B and IFN-inducible transcription factor activation. VCAM1 + PTs were preferentially localized around TLTs and drove inflammation and fibrosis via the production of multiple chemokines or cytokines. Lymphocytes within TLTs expressed Tnf and Ifng at high levels, which synergistically upregulated VCAM1 and chemokine expression in cultured PT cells. In addition, snRNA-seq also identified proinflammatory and profibrotic fibroblasts, which resided within and outside TLTs, respectively. Proinflammatory fibroblasts exhibited STAT1 activation and various chemokine or cytokine production, including CXCL9/CXCL10 and B cell-activating factor, contributing to lymphocyte recruitment and survival. IFN γ upregulated the expression of these molecules in cultured fibroblasts in a STAT1-dependent manner, indicating potential bidirectional interactions between IFN γ -producing CXCR3 + T cells and proinflammatory fibroblasts within TLTs. The cellular and molecular components described in this study were confirmed in human kidneys with TLTs. CONCLUSIONS These findings suggest that TLTs potentially amplify inflammation by providing a microenvironment that allows intense interactions between renal parenchymal and immune cells. These interactions may serve as novel therapeutic targets in kidney diseases involving TLT formation.
Collapse
Affiliation(s)
- Takahisa Yoshikawa
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akiko Oguchi
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan
- Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto, Japan
| | - Naoya Toriu
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto, Japan
| | - Yuki Sato
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takashi Kobayashi
- Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Osamu Ogawa
- Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hironori Haga
- Department of Diagnostic Pathology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Satoko Sakurai
- Department of Life Science Frontiers, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Takuya Yamamoto
- Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto, Japan
- Department of Life Science Frontiers, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
- Medical-risk Avoidance based on iPS Cells Team, RIKEN Center for Advanced Intelligence Project (AIP), Kyoto, Japan
| | - Yasuhiro Murakawa
- RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa, Japan
- Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto, Japan
- IFOM-ETS, Milan, Italy
| | - Motoko Yanagita
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto, Japan
| |
Collapse
|
20
|
Skeby CK, Hummelgaard S, Gustafsen C, Petrillo F, Frederiksen KP, Olsen D, Kristensen T, Ivarsen P, Madsen P, Christensen EI, Nielsen R, Birn H, Glerup S, Weyer K. Proprotein convertase subtilisin/kexin type 9 targets megalin in the kidney proximal tubule and aggravates proteinuria in nephrotic syndrome. Kidney Int 2023; 104:754-768. [PMID: 37406929 DOI: 10.1016/j.kint.2023.06.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 06/04/2023] [Accepted: 06/09/2023] [Indexed: 07/07/2023]
Abstract
Proteinuria is a prominent feature of chronic kidney disease. Interventions that reduce proteinuria slow the progression of chronic kidney disease and the associated risk of cardiovascular disease. Here, we propose a mechanistic coupling between proteinuria and proprotein convertase subtilisin/kexin type 9 (PCSK9), a regulator of cholesterol and a therapeutic target in cardiovascular disease. PCSK9 undergoes glomerular filtration and is captured by megalin, the receptor responsible for driving protein reabsorption in the proximal tubule. Accordingly, megalin-deficient mice and patients carrying megalin pathogenic variants (Donnai Barrow syndrome) were characterized by elevated urinary PCSK9 excretion. Interestingly, PCSK9 knockout mice displayed increased kidney megalin while PCSK9 overexpression resulted in its reduction. Furthermore, PCSK9 promoted trafficking of megalin to lysosomes in cultured proximal tubule cells, suggesting that PCSK9 is a negative regulator of megalin. This effect can be accelerated under disease conditions since either genetic destruction of the glomerular filtration barrier in podocin knockout mice or minimal change disease (a common cause of nephrotic syndrome) in patients resulted in enhanced tubular PCSK9 uptake and urinary PCSK9 excretion. Pharmacological PCSK9 inhibition increased kidney megalin while reducing urinary albumin excretion in nephrotic mice. Thus, glomerular damage increases filtration of PCSK9 and concomitantly megalin degradation, resulting in escalated proteinuria.
Collapse
Affiliation(s)
- Cecilie K Skeby
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Camilla Gustafsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Draupnir Bio, INCUBA Skejby, Aarhus, Denmark
| | | | | | - Ditte Olsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Draupnir Bio, INCUBA Skejby, Aarhus, Denmark
| | - Tilde Kristensen
- Department of Internal Medicine, Renal Unit, Regional Hospital Viborg, Viborg, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Per Ivarsen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Peder Madsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Draupnir Bio, INCUBA Skejby, Aarhus, Denmark
| | | | - Rikke Nielsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Henrik Birn
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Simon Glerup
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Draupnir Bio, INCUBA Skejby, Aarhus, Denmark
| | - Kathrin Weyer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
| |
Collapse
|
21
|
Yoshimura Y, Muto Y, Omachi K, Miner JH, Humphreys BD. Elucidating the Proximal Tubule HNF4A Gene Regulatory Network in Human Kidney Organoids. J Am Soc Nephrol 2023; 34:1672-1686. [PMID: 37488681 PMCID: PMC10561821 DOI: 10.1681/asn.0000000000000197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 07/08/2023] [Indexed: 07/26/2023] Open
Abstract
SIGNIFICANCE STATEMENT HNF4 genes promote proximal tubule differentiation in mice, but their function in human nephrogenesis is not fully defined. This study uses human pluripotent stem cell (PSC)-derived kidney organoids as a model to investigate HNF4A and HNF4G functions. The loss of HNF4A , but not HNF4G , impaired reabsorption-related molecule expression and microvilli formation in human proximal tubules. Cleavage under targets and release using nuclease (CUT&RUN) sequencing and CRISPR-mediated transcriptional activation (CRISPRa) further confirm that HNF4A directly regulates its target genes. Human kidney organoids provide a good model for studying transcriptional regulation in human kidney development. BACKGROUND The proximal tubule plays a major role in electrolyte homeostasis. Previous studies have shown that HNF4A regulates reabsorption-related genes and promotes proximal tubule differentiation during murine kidney development. However, the functions and gene regulatory mechanisms of HNF4 family genes in human nephrogenesis have not yet been investigated. METHODS We generated HNF4A -knock out (KO), HNF4G -KO, and HNF4A/4G -double KO human pluripotent stem cell lines, differentiated each into kidney organoids, and used immunofluorescence analysis, electron microscopy, and RNA-seq to analyze them. We probed HNF4A-binding sites genome-wide by cleavage under targets and release using nuclease sequencing in both human adult kidneys and kidney organoid-derived proximal tubular cells. Clustered Regularly Interspaced Short Palindromic Repeats-mediated transcriptional activation validated HNF4A and HNF4G function in proximal tubules during kidney organoid differentiation. RESULTS Organoids lacking HNF4A , but not HNF4G , showed reduced expression of transport-related, endocytosis-related, and brush border-related genes, as well as disorganized brush border structure in the apical lumen of the organoid proximal tubule. Cleavage under targets and release using nuclease revealed that HNF4A primarily bound promoters and enhancers of genes that were downregulated in HNF4A -KO, suggesting direct regulation. Induced expression of HNF4A or HNF4G by CRISPR-mediated transcriptional activation drove increased expression of selected target genes during kidney organoid differentiation. CONCLUSIONS This study reveals regulatory mechanisms of HNF4A and HNF4G during human proximal tubule differentiation. The experimental strategy can be applied more broadly to investigate transcriptional regulation in human kidney development.
Collapse
Affiliation(s)
- Yasuhiro Yoshimura
- Division of Nephrology, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Yoshiharu Muto
- Division of Nephrology, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Kohei Omachi
- Division of Nephrology, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Jeffrey H. Miner
- Division of Nephrology, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Benjamin D. Humphreys
- Division of Nephrology, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| |
Collapse
|
22
|
Long KR, Rbaibi Y, Kashlan OB, Weisz OA. Receptor-associated protein impairs ligand binding to megalin and megalin-dependent endocytic flux in proximal tubule cells. Am J Physiol Renal Physiol 2023; 325:F457-F464. [PMID: 37534387 DOI: 10.1152/ajprenal.00165.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/11/2023] [Accepted: 07/31/2023] [Indexed: 08/04/2023] Open
Abstract
Proximal tubule (PT) cells retrieve albumin and a broad array of other ligands from the glomerular ultrafiltrate. Efficient uptake of albumin requires PT expression of both megalin and cubilin receptors. Although most proteins engage cubilin selectively, megalin is required to maintain robust flux through the apical endocytic pathway. Receptor-associated protein (RAP) is a chaperone that directs megalin to the cell surface, and recombinant RAP dramatically inhibits the uptake of numerous megalin and cubilin ligands. The mechanism by which this occurs has been suggested to involve competitive inhibition of ligand binding and/or conformational changes in megalin that prevent interaction with ligands and/or with cubilin. To discriminate between these possibilities, we determined the effect of RAP on endocytosis of albumin, which binds to cubilin and megalin receptors with high and low affinity, respectively. Uptake was quantified in opossum kidney (OK) cells and in megalin or cubilin (Cubn) knockout (KO) clones. Surprisingly, RAP inhibited fluid-phase uptake in addition to receptor-mediated uptake in OK cells and Cubn KO cells but had no effect on endocytosis when megalin was absent. The apparent Ki for RAP inhibition of albumin uptake was 10-fold higher in Cubn KO cells compared with parental OK cells. We conclude that in addition to its predicted high-affinity competition for ligand binding to megalin, the primary effect of RAP on PT cell endocytosis is to globally dampen megalin-dependent endocytic flux. Our data explain the complex effects of RAP on binding and uptake of filtered proteins and reveal a novel role in modulating endocytosis in PT cells.NEW & NOTEWORTHY Receptor-associated protein inhibits binding and uptake of all known endogenous ligands by megalin and cubilin receptors via unknown mechanism(s). Here, we took advantage of recently generated knockout cell lines to dissect the effect of this protein on megalin- and cubilin-mediated endocytosis. Our study reveals a novel role for receptor-associated protein in blocking megalin-stimulated endocytic uptake of fluid-phase markers and receptor-bound ligands in proximal tubule cells in addition to its direct effect on ligand binding to megalin receptors.
Collapse
Affiliation(s)
- Kimberly R Long
- Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Youssef Rbaibi
- Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Ossama B Kashlan
- Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Ora A Weisz
- Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| |
Collapse
|
23
|
Molitoris BA, Wagner MC. Is Albumin Toxic to the Kidney?: It Depends. Clin J Am Soc Nephrol 2023; 18:1222-1224. [PMID: 36942999 PMCID: PMC10564333 DOI: 10.2215/cjn.0000000000000153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 03/16/2023] [Indexed: 03/23/2023]
Affiliation(s)
- Bruce A Molitoris
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana
| | | |
Collapse
|
24
|
McDonough AA, Layton AT. Sex differences in renal electrolyte transport. Curr Opin Nephrol Hypertens 2023; 32:467-475. [PMID: 37382185 PMCID: PMC10526720 DOI: 10.1097/mnh.0000000000000909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023]
Abstract
PURPOSE OF REVIEW Women experience unique life events, for example, pregnancy and lactation, that challenge renal regulation of electrolyte homeostasis. Recent analyses of nephron organization in female vs. male rodent kidneys, revealed distinct sexual dimorphisms in electrolyte transporter expression, abundance, and activity. This review aims to provide an overview of electrolyte transporters' organization and operation in female compared with the commonly studied male kidney, and the (patho)physiologic consequences of the differences. RECENT FINDINGS When electrolyte transporters are assessed in kidney protein homogenates from both sexes, relative transporter abundance ratios in females/males are less than one along proximal tubule and greater than one post macula densa, which is indicative of a 'downstream shift' in fractional reabsorption of electrolytes in females. This arrangement improves the excretion of a sodium load, challenges potassium homeostasis, and is consistent with the lower blood pressure and greater pressure natriuresis observed in premenopausal women. SUMMARY We summarize recently reported new knowledge about sex differences in renal transporters: abundance and expression along nephron, implications for regulation by Na + , K + and angiotensin II, and mathematical models of female nephron function.
Collapse
Affiliation(s)
- Alicia A. McDonough
- Department of Physiology and Neuroscience, Keck School of Medicine of the University of Southern California, Los Angeles, CA
| | - Anita T. Layton
- Departments of Applied Mathematics and Biology, University of Waterloo, Waterloo, Ontario, Canada; Cheriton School of Computer Science, University of Waterloo, Waterloo, Ontario, Canada; School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada
| |
Collapse
|
25
|
Denic A, Gaddam M, Moustafa A, Mullan AF, Luehrs AC, Sharma V, Thompson RH, Smith ML, Alexander MP, Lerman LO, Barisoni L, Rule AD. Tubular and Glomerular Size by Cortex Depth as Predictor of Progressive CKD after Radical Nephrectomy for Tumor. J Am Soc Nephrol 2023; 34:1535-1545. [PMID: 37430426 PMCID: PMC10482069 DOI: 10.1681/asn.0000000000000180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/08/2023] [Indexed: 07/12/2023] Open
Abstract
SIGNIFICANCE STATEMENT Glomerular size differs by cortex depth. Larger nephrons are prognostic of progressive kidney disease, but it is unknown whether this risk differs by cortex depth or by glomeruli versus proximal or distal tubule size. We studied the average minor axis diameter in oval proximal and distal tubules separately and by cortex depth in patients who had radical nephrectomy to remove a tumor from 2019 to 2020. In adjusted analyses, larger glomerular volume in the middle and deep cortex predicted progressive kidney disease. Wider proximal tubular diameter did not predict progressive kidney disease independent of glomerular volume. Wider distal tubular diameter showed a gradient of strength of prediction of progressive kidney disease in the more superficial cortex than in the deep cortex. BACKGROUND Larger nephrons are prognostic of progressive kidney disease, but whether this risk differs by nephron segments or by depth in the cortex is unclear. METHODS We studied patients who underwent radical nephrectomy for a tumor between 2000 and 2019. Large wedge kidney sections were scanned into digital images. We estimated the diameters of proximal and distal tubules by the minor axis of oval tubular profiles and estimated glomerular volume with the Weibel-Gomez stereological model. Analyses were performed separately in the superficial, middle, and deep cortex. Cox proportional hazard models assessed the risk of progressive CKD (dialysis, kidney transplantation, sustained eGFR <10 ml/min per 1.73 m 2 , or a sustained 40% decline from the postnephrectomy baseline eGFR) with glomerular volume or tubule diameters. At each cortical depth, models were unadjusted, adjusted for glomerular volume or tubular diameter, and further adjusted for clinical characteristics (age, sex, body mass index, hypertension, diabetes, postnephrectomy baseline eGFR, and proteinuria). RESULTS Among 1367 patients were 62 progressive CKD events during a median follow-up of 4.5 years. Glomerular volume predicted CKD outcomes at all depths, but only in the middle and deep cortex after adjusted analyses. Proximal tubular diameter also predicted progressive CKD at any depth but not after adjusted analyses. Distal tubular diameter showed a gradient of more strongly predicting progressive CKD in the superficial than deep cortex, even in adjusted analysis. CONCLUSIONS Larger glomeruli are independent predictors of progressive CKD in the deeper cortex, whereas in the superficial cortex, wider distal tubular diameters are an independent predictor of progressive CKD.
Collapse
Affiliation(s)
- Aleksandar Denic
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Mrunanjali Gaddam
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Amr Moustafa
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Aidan F. Mullan
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
| | - Anthony C. Luehrs
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
| | - Vidit Sharma
- Department of Urology, Mayo Clinic, Rochester, Minnesota
| | | | - Maxwell L. Smith
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, Arizona
| | - Mariam P. Alexander
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Lilach O. Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Laura Barisoni
- Department of Pathology and Medicine, Duke University, Durham, North Carolina
| | - Andrew D. Rule
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
- Division of Epidemiology, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
26
|
Lea WA, Winklhofer T, Zelenchuk L, Sharma M, Rossol-Allison J, Fields TA, Reif G, Calvet JP, Bakeberg JL, Wallace DP, Ward CJ. Polycystin-1 Interacting Protein-1 (CU062) Interacts with the Ectodomain of Polycystin-1 (PC1). Cells 2023; 12:2166. [PMID: 37681898 PMCID: PMC10487028 DOI: 10.3390/cells12172166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/07/2023] [Accepted: 08/14/2023] [Indexed: 09/09/2023] Open
Abstract
The PKD1 gene, encoding protein polycystin-1 (PC1), is responsible for 85% of cases of autosomal dominant polycystic kidney disease (ADPKD). PC1 has been shown to be present in urinary exosome-like vesicles (PKD-ELVs) and lowered in individuals with germline PKD1 mutations. A label-free mass spectrometry comparison of urinary PKD-ELVs from normal individuals and those with PKD1 mutations showed that several proteins were reduced to a degree that matched the decrease observed in PC1 levels. Some of these proteins, such as polycystin-2 (PC2), may be present in a higher-order multi-protein assembly with PC1-the polycystin complex (PCC). CU062 (Q9NYP8) is decreased in ADPKD PKD-ELVs and, thus, is a candidate PCC component. CU062 is a small glycoprotein with a signal peptide but no transmembrane domain and can oligomerize with itself and interact with PC1. We investigated the localization of CU062 together with PC1 and PC2 using immunofluorescence (IF). In nonconfluent cells, all three proteins were localized in close proximity to focal adhesions (FAs), retraction fibers (RFs), and RF-associated extracellular vesicles (migrasomes). In confluent cells, primary cilia had PC1/PC2/CU062 + extracellular vesicles adherent to their plasma membrane. In cells exposed to mitochondrion-decoupling agents, we detected the development of novel PC1/CU062 + ring-like structures that entrained swollen mitochondria. In contact-inhibited cells under mitochondrial stress, PC1, PC2, and CU062 were observed on large, apically budding extracellular vesicles, where the proteins formed a reticular network on the membrane. CU062 interacts with PC1 and may have a role in the identification of senescent mitochondria and their extrusion in extracellular vesicles.
Collapse
Affiliation(s)
- Wendy A. Lea
- Department of Nephrology and Hypertension, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, 3901 Rainbow Blvd., Mail Stop 3018, KS 66160, USA (D.P.W.)
| | - Thomas Winklhofer
- Department of Nephrology and Hypertension, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, 3901 Rainbow Blvd., Mail Stop 3018, KS 66160, USA (D.P.W.)
| | - Lesya Zelenchuk
- Department of Nephrology and Hypertension, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, 3901 Rainbow Blvd., Mail Stop 3018, KS 66160, USA (D.P.W.)
| | - Madhulika Sharma
- Department of Nephrology and Hypertension, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, 3901 Rainbow Blvd., Mail Stop 3018, KS 66160, USA (D.P.W.)
| | | | - Timothy A. Fields
- Department of Pathology & Laboratory Medicine, University of Kansas Medical Center, 3901 Rainbow Blvd., Mail Stop 3062, Kansas City, KS 66160, USA
| | - Gail Reif
- Department of Nephrology and Hypertension, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, 3901 Rainbow Blvd., Mail Stop 3018, KS 66160, USA (D.P.W.)
| | - James P. Calvet
- Department of Nephrology and Hypertension, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, 3901 Rainbow Blvd., Mail Stop 3018, KS 66160, USA (D.P.W.)
| | - Jason L. Bakeberg
- Department of Nephrology and Hypertension, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, 3901 Rainbow Blvd., Mail Stop 3018, KS 66160, USA (D.P.W.)
| | - Darren P. Wallace
- Department of Nephrology and Hypertension, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, 3901 Rainbow Blvd., Mail Stop 3018, KS 66160, USA (D.P.W.)
| | - Christopher J. Ward
- Department of Nephrology and Hypertension, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, 3901 Rainbow Blvd., Mail Stop 3018, KS 66160, USA (D.P.W.)
| |
Collapse
|
27
|
Liu H, Sun Q, Ding Z, Shi W, Wang WH, Zhang C. Adenosine stimulates the basolateral 50 pS K + channel in renal proximal tubule via adenosine-A1 receptor. Front Physiol 2023; 14:1242975. [PMID: 37700760 PMCID: PMC10493268 DOI: 10.3389/fphys.2023.1242975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/14/2023] [Indexed: 09/14/2023] Open
Abstract
Background: The basolateral potassium channels play an important role in maintaining the membrane transport in the renal proximal tubules (PT) and adenosine receptors have been shown to regulate the trans-epithelial Na+ absorption in the PT. The aim of the present study is to explore whether adenosine also regulates the basolateral K+ channel of the PT and to determine the adenosine receptor type and the signaling pathway which mediates the effect of adenosine on the K+ channel. Methods: We have used the single channel recording to examine the basolateral K+ channel activity in the proximal tubules of the mouse kidney. All experiments were performed in cell-attached patches. Results: Single channel recording has detected a 50 pS inwardly-rectifying K+ channel with high channel open probability and this 50 pS K+ channel is a predominant type K+ channel in the basolateral membrane of the mouse PT. Adding adenosine increased 50 pS K+ channel activity in cell-attached patches, defined by NPo (a product of channel Numbers and Open Probability). The adenosine-induced stimulation of the 50 pS K+ channel was absent in the PT pretreated with DPCPX, a selective inhibitor of adenosine A1 receptor. In contrast, adenosine was still able to stimulate the 50 pS K+ channel in the PT pretreated with CP-66713, a selective adenosine A2 receptor antagonist. This suggests that the stimulatory effect of adenosine on the 50 pS K+ channel of the PT was mediated by adenosine-A1 receptor. Moreover, the effect of adenosine on the 50 pS K+ channel was blocked in the PT pretreated with U-73122 or Calphostin C, suggesting that adenosine-induced stimulation of the 50 pS K+ channels of the PT was due to the activation of phospholipase C (PLC) and protein kinase C (PKC) pathway. In contrast, the inhibition of phospholipase A2 (PLA2) with AACOCF3 or inhibition of protein kinase A (PKA) with H8 failed to block the adenosine-induced stimulation of the 50 pS K+ channel of the PT. Conclusion: We conclude that adenosine activates the 50 pS K+ channels in the basolateral membrane of PT via adenosine-A1 receptor. Furthermore, the effect of adenosine on the 50 pS K+ channel is mediated by PLC-PKC signaling pathway.
Collapse
Affiliation(s)
- Hao Liu
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | - Qi Sun
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | - Zheng Ding
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | - Wensen Shi
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, NY, United States
| | - Chengbiao Zhang
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| |
Collapse
|
28
|
Al-Marsoummi S, Mehus AA, Shrestha S, Rice R, Rossow B, Somji S, Garrett SH, Sens DA. Proteasomes Are Critical for Maintenance of CD133+CD24+ Kidney Progenitor Cells. Int J Mol Sci 2023; 24:13303. [PMID: 37686107 PMCID: PMC10487892 DOI: 10.3390/ijms241713303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/19/2023] [Accepted: 08/25/2023] [Indexed: 09/10/2023] Open
Abstract
Kidney progenitor cells, although rare and dispersed, play a key role in the repair of renal tubules after acute kidney damage. However, understanding these cells has been challenging due to the limited access to primary renal tissues and the absence of immortalized cells to model kidney progenitors. Previously, our laboratory utilized the renal proximal tubular epithelial cell line, RPTEC/TERT1, and the flow cytometry technique to sort and establish a kidney progenitor cell model called Human Renal Tubular Precursor TERT (HRTPT) which expresses CD133 and CD24 and exhibits the characteristics of kidney progenitors, such as self-renewal capacity and multi-potential differentiation. In addition, a separate cell line was established, named Human Renal Epithelial Cell 24 TERT (HREC24T), which lacks CD133 expression and shows no progenitor features. To further characterize HRTPT CD133+CD24+ progenitor cells, we performed proteomic profiling which showed high proteasomal expression in HRTPT kidney progenitor cells. RT-qPCR, Western blot, and flow cytometry analysis showed that HRTPT cells possess higher proteasomal expression and activity compared to HREC24T non-progenitor cells. Importantly, inhibition of the proteasomes with bortezomib reduced the expression of progenitor markers and obliterated the potential for self-renewal and differentiation of HRTPT progenitor cells. In conclusion, proteasomes are critical in preserving progenitor markers expression and self-renewal capacity in HRTPT kidney progenitors.
Collapse
Affiliation(s)
- Sarmad Al-Marsoummi
- Department of Pathology, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Li Y, Gu W, Hepokoski M, Pham H, Tham R, Kim YC, Simonson TS, Singh P. Energy Metabolism Dysregulation in Chronic Kidney Disease. Kidney360 2023; 4:1080-1094. [PMID: 37222594 PMCID: PMC10476685 DOI: 10.34067/kid.0000000000000153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 05/08/2023] [Indexed: 05/25/2023]
Abstract
Key Points There is significant enrichment in metabolic pathways in early stages in the subtotal nephrectomy model of CKD. Proximal tubular mitochondrial respiration is suppressed likely from mitochondrial dysfunction in substrate utilization and ATP synthesis. There is significant suppression of pyruvate dehydrogenase and increased glycolysis in proximal tubules. Background CKD is a significant contributor to morbidity and mortality. A better understanding of mechanisms underlying CKD progression is indispensable for developing effective therapies. Toward this goal, we addressed specific gaps in knowledge regarding tubular metabolism in the pathogenesis of CKD using the subtotal nephrectomy (STN) model in mice. Methods Weight- and age‐matched male 129X1/SvJ mice underwent sham or STN surgeries. We conducted serial GFR and hemodynamic measurements up to 16 weeks after sham and STN surgery and established the 4-week time point for subsequent studies. Results For a comprehensive assessment of renal metabolism, we conducted transcriptomic analyses, which showed significant enrichment of pathways involved in fatty acid metabolism, gluconeogenesis, glycolysis, and mitochondrial metabolism in STN kidneys. Expression of rate-limiting fatty acid oxidation and glycolytic enzymes was increased in STN kidneys, and proximal tubules in STN kidneys exhibited increased functional glycolysis but decreased mitochondrial respiration, despite an increase in mitochondrial biogenesis. Assessment of the pyruvate dehydrogenase complex pathway showed significant suppression of pyruvate dehydrogenase, suggesting decreased provision of acetyl CoA from pyruvate for the citric acid cycle to fuel mitochondrial respiration. Conclusion Metabolic pathways are significantly altered in response to kidney injury and may play an important role in the disease progression.
Collapse
Affiliation(s)
- Ying Li
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
- VA San Diego Healthcare System, San Diego, California
| | - Wanjun Gu
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
| | - Mark Hepokoski
- VA San Diego Healthcare System, San Diego, California
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
| | - Hai Pham
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
- VA San Diego Healthcare System, San Diego, California
| | - Rick Tham
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
- VA San Diego Healthcare System, San Diego, California
| | - Young Chul Kim
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
- VA San Diego Healthcare System, San Diego, California
| | - Tatum S. Simonson
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
| | - Prabhleen Singh
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
- VA San Diego Healthcare System, San Diego, California
| |
Collapse
|
30
|
Namazian Jam N, Gottlöber F, Hempel M, Dzekhtsiarova Y, Behrens S, Sonntag F, Sradnick J, Hugo C, Schmieder F. Microphysiological Conditions Do Not Affect MDR1-Mediated Transport of Rhodamine 123 above an Artificial Proximal Tubule. Biomedicines 2023; 11:2045. [PMID: 37509683 PMCID: PMC10376999 DOI: 10.3390/biomedicines11072045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/15/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
Despite disadvantages, such as high cost and their poor predictive value, animal experiments are still the state of the art for pharmaceutical substance testing. One reason for this problem is the inability of standard cell culture methods to emulate the physiological environment necessary to recapitulate in vivo processes. Microphysiological systems offer the opportunity to close this gap. In this study, we utilize a previously employed microphysiological system to examine the impact of pressure and flow on the transportation of substances mediated by multidrug resistance protein 1 (MDR1) across an artificial cell-based tubular barrier. By using a miniaturized fluorescence measurement device, we could continuously track the MDR1-mediated transport of rhodamine 123 above the artificial barrier over 48 h. We proved that applying pressure and flow affects both active and passive transport of rhodamine 123. Using experimental results and curve fittings, the kinetics of MDR1-mediated transport as well as passive transport were investigated; thus, a kinetic model that explains this transport above an artificial tubular barrier was identified. This kinetic model demonstrates that the simple Michaelis-Menten model is not an appropriate model to explain the MDR1-mediated transport; instead, Hill kinetics, with Hill slope of n = 2, is a better fit. The kinetic values, Km, Vmax, and apparent permeability (Papp), obtained in this study are comparable with other in vivo and in vitro studies. Finally, the presented proximal tubule-on-a-chip can be used for pharmaceutical substance testing and to investigate pharmacokinetics of the renal transporter MDR1.
Collapse
Affiliation(s)
- Negin Namazian Jam
- Fraunhofer Institute for Material and Beam Technology IWS, 01277 Dresden, Germany
| | - Felix Gottlöber
- Fraunhofer Institute for Material and Beam Technology IWS, 01277 Dresden, Germany
| | - Melanie Hempel
- Fraunhofer Institute for Material and Beam Technology IWS, 01277 Dresden, Germany
| | - Yuliya Dzekhtsiarova
- Fraunhofer Institute for Material and Beam Technology IWS, 01277 Dresden, Germany
| | - Stephan Behrens
- Fraunhofer Institute for Material and Beam Technology IWS, 01277 Dresden, Germany
| | - Frank Sonntag
- Fraunhofer Institute for Material and Beam Technology IWS, 01277 Dresden, Germany
| | - Jan Sradnick
- Department of Internal Medicine III, University Hospital Carl Gustav Carus, 01307 Dresden, Germany
| | - Christian Hugo
- Department of Internal Medicine III, University Hospital Carl Gustav Carus, 01307 Dresden, Germany
| | - Florian Schmieder
- Fraunhofer Institute for Material and Beam Technology IWS, 01277 Dresden, Germany
| |
Collapse
|
31
|
Peres RAS, Peruchetti DB, Silva-Aguiar RP, Teixeira DE, Gomes CP, Takiya CM, Pinheiro AAS, Caruso-Neves C. Rapamycin treatment induces tubular proteinuria: role of megalin-mediated protein reabsorption. Front Pharmacol 2023; 14:1194816. [PMID: 37484026 PMCID: PMC10359992 DOI: 10.3389/fphar.2023.1194816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/27/2023] [Indexed: 07/25/2023] Open
Abstract
Introduction: Rapamycin is an immunosuppressor that acts by inhibiting the serine/threonine kinase mechanistic target of rapamycin complex 1. Therapeutic use of rapamycin is limited by its adverse effects. Proteinuria is an important marker of kidney damage and a risk factor for kidney diseases progression and has been reported in patients and animal models treated with rapamycin. However, the mechanism underlying proteinuria induced by rapamycin is still an open matter. In this work, we investigated the effects of rapamycin on parameters of renal function and structure and on protein handling by proximal tubule epithelial cells (PTECs). Methods: Healthy BALB/c mice were treated with 1.5 mg/kg rapamycin by oral gavage for 1, 3, or 7 days. At the end of each treatment, the animals were kept in metabolic cages and renal function and structural parameters were analyzed. LLC-PK1 cell line was used as a model of PTECs to test specific effect of rapamycin. Results: Rapamycin treatment did not change parameters of glomerular structure and function. Conversely, there was a transient increase in 24-h proteinuria, urinary protein to creatinine ratio (UPCr), and albuminuria in the groups treated with rapamycin. In accordance with these findings, rapamycin treatment decreased albumin-fluorescein isothiocyanate uptake in the renal cortex. This effect was associated with reduced brush border expression and impaired subcellular distribution of megalin in PTECs. The effect of rapamycin seems to be specific for albumin endocytosis machinery because it did not modify renal sodium handling or (Na++K+)ATPase activity in BALB/c mice and in the LLC-PK1 cell line. A positive Pearson correlation was found between megalin expression and albumin uptake while an inverse correlation was shown between albumin uptake and UPCr or 24-h proteinuria. Despite its effect on albumin handling in PTECs, rapamycin treatment did not induce tubular injury measured by interstitial space and collagen deposition. Conclusion: These findings suggest that proteinuria induced by rapamycin could have a tubular rather than a glomerular origin. This effect involves a specific change in protein endocytosis machinery. Our results open new perspectives on understanding the undesired effect of proteinuria generated by rapamycin.
Collapse
Affiliation(s)
- Rodrigo A. S. Peres
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Diogo B. Peruchetti
- Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Rodrigo P. Silva-Aguiar
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Douglas E. Teixeira
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carlos P. Gomes
- Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- School of Medicine and Surgery, Federal University of the State of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Christina M. Takiya
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ana Acacia S. Pinheiro
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Rio de Janeiro Innovation Network in Nanosystems for Health-NanoSAÚDE/FAPERJ, Rio de Janeiro, Brazil
| | - Celso Caruso-Neves
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Rio de Janeiro Innovation Network in Nanosystems for Health-NanoSAÚDE/FAPERJ, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Regenerative Medicine, Rio de Janeiro, Brazil
| |
Collapse
|
32
|
Baer PC, Neuhoff AK, Schubert R. microRNA Expression of Renal Proximal Tubular Epithelial Cells and Their Extracellular Vesicles in an Inflammatory Microenvironment In Vitro. Int J Mol Sci 2023; 24:11069. [PMID: 37446246 DOI: 10.3390/ijms241311069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 06/29/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Renal proximal tubular epithelial cells (PTCs) are central players during renal inflammation. In response to inflammatory signals, PTCs not only self-express altered mRNAs, microRNAs (miRNAs), proteins, and lipids, but also release altered extracellular vesicles (EVs). These EVs also carry inflammation-specific cargo molecules and are key players in cell-cell-communication. Understanding the precise molecular and cellular mechanisms that lead to inflammation in the kidney is the most important way to identify early targets for the prevention or treatment of acute kidney injury. Therefore, highly purified human PTCs were used as an in vitro model to study the cellular response to an inflammatory microenvironment. A cytokine-induced inflammatory system was established to analyze different miRNA expression in cells and their EVs. In detail, we characterized the altered miR expression of PTCs and their released EVs during induced inflammation and showed that 12 miRNAs were significantly regulated in PTCs (6 upregulated and 6 downregulated) and 9 miRNAs in EVs (8 upregulated and 1 downregulated). We also showed that only three of the miRNAs were found to overlap between cells and EVs. As shown by the KEGG pathway analysis, these three miRNAs (miR-146a-5p, miR-147b, and miR-155-5p) are functionally involved in the regulation of the Toll-like receptor signaling pathway and significantly correlated with the inflammatory mediators IL6 and ICAM1 released by stimulated PTCs. Especially with regard to a possible clinical use of miRs as new biomarkers, an accurate characterization of the miR expression altered during inflammatory processes is of enormous importance.
Collapse
Affiliation(s)
- Patrick C Baer
- Department of Internal Medicine 4, Nephrology, University Hospital, Goethe-University, 60596 Frankfurt/M., Germany
| | - Ann-Kathrin Neuhoff
- Division of Allergology, Pneumology and Cystic Fibrosis, Department for Children and Adolescents, University Hospital, Goethe-University, 60596 Frankfurt/M., Germany
| | - Ralf Schubert
- Division of Allergology, Pneumology and Cystic Fibrosis, Department for Children and Adolescents, University Hospital, Goethe-University, 60596 Frankfurt/M., Germany
| |
Collapse
|
33
|
Inagi R, Yoshioka K. Stray tubules: the varied and dynamic fate of tubular cells. Kidney Int 2023; 104:19-21. [PMID: 36804410 DOI: 10.1016/j.kint.2023.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 02/09/2023] [Indexed: 02/19/2023]
Affiliation(s)
- Reiko Inagi
- Division of CKD Pathophysiology, The University of Tokyo, Graduate School of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan.
| | - Kentaro Yoshioka
- Division of CKD Pathophysiology, The University of Tokyo, Graduate School of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan
| |
Collapse
|
34
|
Cippà PE, McMahon AP. Proximal tubule responses to injury: interrogation by single-cell transcriptomics. Curr Opin Nephrol Hypertens 2023; 32:352-358. [PMID: 37074682 PMCID: PMC10330172 DOI: 10.1097/mnh.0000000000000893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
PURPOSE OF REVIEW Acute kidney injury (AKI) occurs in approximately 10-15% of patients admitted to hospital and is associated with adverse clinical outcomes. Despite recent advances, management of patients with AKI is still mainly supportive, including the avoidance of nephrotoxins, volume and haemodynamic management and renal replacement therapy. A better understanding of the renal response to injury is the prerequisite to overcome current limitations in AKI diagnostics and therapy. RECENT FINDINGS Single-cell technologies provided new opportunities to study the complexity of the kidney and have been instrumental for rapid advancements in the understanding of the cellular and molecular mechanisms of AKI. SUMMARY We provide an update on single-cell technologies and we summarize the recent discoveries on the cellular response to injury in proximal tubule cells from the early response in AKI, to the mechanisms of tubule repair and the relevance of maladaptive tubule repair in the transition to chronic kidney disease.
Collapse
Affiliation(s)
- Pietro E Cippà
- Division of Nephrology, Ente Ospedaliero Cantonale, Lugano, Switzerland
- Faculity of Biomedical Sciences, Università della Svizzera Italiana, Lugano Switzerland
| | - Andrew P McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
| |
Collapse
|
35
|
Petrica L, Vlad A, Gadalean F, Muntean DM, Vlad D, Dumitrascu V, Bob F, Milas O, Suteanu-Simulescu A, Glavan M, Jianu DC, Ursoniu S, Balint L, Mogos-Stefan M, Ienciu S, Cretu OM, Popescu R. Mitochondrial DNA Changes in Blood and Urine Display a Specific Signature in Relation to Inflammation in Normoalbuminuric Diabetic Kidney Disease in Type 2 Diabetes Mellitus Patients. Int J Mol Sci 2023; 24:9803. [PMID: 37372951 DOI: 10.3390/ijms24129803] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/05/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Mitochondrial dysfunction is an important mechanism contributing to the development and progression of diabetic kidney disease (DKD). Mitochondrial DNA (mtDNA) levels in blood and urine were evaluated in relation to podocyte injury and proximal tubule (PT) dysfunction, as well as to a specific inflammatory response in normoalbuminuric DKD. A total of 150 type 2 diabetes mellitus (DM) patients (52 normoalbuminuric, 48 microalbuminuric, and 50 macroalbuminuric ones, respectively) and 30 healthy controls were assessed concerning the urinary albumin/creatinine ratio (UACR), biomarkers of podocyte damage (synaptopodin and podocalyxin), PT dysfunction (kidney injury molecule-1 (KIM-1) and N-acetyl-β-(D)-glucosaminidase (NAG)), and inflammation (serum and urinary interleukins (IL-17A, IL-18, and IL-10)). MtDNA-CN and nuclear DNA (nDNA) were quantified in peripheral blood and urine via qRT-PCR. MtDNA-CN was defined as the ratio of the number of mtDNA/nDNA copies via analysis of the CYTB/B2M and ND2/B2M ratio. Multivariable regression analysis provided models in which serum mtDNA directly correlated with IL-10 and indirectly correlated with UACR, IL-17A, and KIM-1 (R2 = 0.626; p < 0.0001). Urinary mtDNA directly correlated with UACR, podocalyxin, IL-18, and NAG, and negatively correlated with eGFR and IL-10 (R2 = 0.631; p < 0.0001). Mitochondrial DNA changes in serum and urine display a specific signature in relation to inflammation both at the podocyte and tubular levels in normoalbuminuric type 2 DM patients.
Collapse
Affiliation(s)
- Ligia Petrica
- Department of Internal Medicine II, Division of Nephrology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Cognitive Research in Neuropsychiatric Pathology (Neuropsy-Cog), Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Center for Translational Research and Systems Medicine, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
| | - Adrian Vlad
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
- Department of Internal Medicine II, Division of Diabetes and Metabolic Diseases, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
| | - Florica Gadalean
- Department of Internal Medicine II, Division of Nephrology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
| | - Danina Mirela Muntean
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Center for Translational Research and Systems Medicine, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Department of Functional Sciences III, Division of Pathophysiology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
| | - Daliborca Vlad
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
- Department of Biochemistry and Pharmacology IV, Division of Pharmacology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
| | - Victor Dumitrascu
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
- Department of Biochemistry and Pharmacology IV, Division of Pharmacology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
| | - Flaviu Bob
- Department of Internal Medicine II, Division of Nephrology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
| | - Oana Milas
- Department of Internal Medicine II, Division of Nephrology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
| | - Anca Suteanu-Simulescu
- Department of Internal Medicine II, Division of Nephrology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
| | - Mihaela Glavan
- Department of Internal Medicine II, Division of Nephrology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
| | - Dragos Catalin Jianu
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Cognitive Research in Neuropsychiatric Pathology (Neuropsy-Cog), Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
- Department of Neurosciences VIII, Division of Neurology I, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
| | - Sorin Ursoniu
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Cognitive Research in Neuropsychiatric Pathology (Neuropsy-Cog), Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Center for Translational Research and Systems Medicine, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
- Department of Functional Sciences III, Division of Public Health and Health and History of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
| | - Lavinia Balint
- Department of Internal Medicine II, Division of Nephrology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
| | - Maria Mogos-Stefan
- Department of Internal Medicine II, Division of Nephrology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
| | - Silvia Ienciu
- Department of Internal Medicine II, Division of Nephrology, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
| | - Octavian Marius Cretu
- Department of Surgery I, Division of Surgical Semiology I, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- Emergency Clinical Municipal Hospital Timisoara, 300041 Timisoara, Romania
| | - Roxana Popescu
- Centre for Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
- County Emergency Hospital Timisoara, 300723 Timisoara, Romania
- Department of Microscopic Morphology II, Division of Cell and Molecular Biology II, "Victor Babes" University of Medicine and Pharmacy, No. 2, Eftimie Murgu Sq., 300041 Timisoara, Romania
| |
Collapse
|
36
|
Li X, Zhuo J. Intracellular Angiotensin II Stimulation of Sodium Transporter Expression in Proximal Tubule Cells via AT 1 (AT 1a) Receptor-Mediated, MAP Kinases ERK1/2- and NF-кB-Dependent Signaling Pathways. Cells 2023; 12:1492. [PMID: 37296613 PMCID: PMC10252550 DOI: 10.3390/cells12111492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/23/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
The current prevailing paradigm in the renin-angiotensin system dictates that most, if not all, biological, physiological, and pathological responses to its most potent peptide, angiotensin II (Ang II), are mediated by extracellular Ang II activating its cell surface receptors. Whether intracellular (or intracrine) Ang II and its receptors are involved remains incompletely understood. The present study tested the hypothesis that extracellular Ang II is taken up by the proximal tubules of the kidney by an AT1 (AT1a) receptor-dependent mechanism and that overexpression of an intracellular Ang II fusion protein (ECFP/Ang II) in mouse proximal tubule cells (mPTC) stimulates the expression of Na+/H+ exchanger 3 (NHE3), Na+/HCO3- cotransporter, and sodium and glucose cotransporter 2 (Sglt2) by AT1a/MAPK/ERK1/2/NF-kB signaling pathways. mPCT cells derived from male wild-type and type 1a Ang II receptor-deficient mice (Agtr1a-/-) were transfected with an intracellular enhanced cyan fluorescent protein-tagged Ang II fusion protein, ECFP/Ang II, and treated without or with AT1 receptor blocker losartan, AT2 receptor blocker PD123319, MEK1/MEK2 inhibitor U0126, NF-кB inhibitor RO 106-9920, or p38 MAP kinase inhibitor SB202196, respectively. In wild-type mPCT cells, the expression of ECFP/Ang II significantly increased NHE3, Na+/HCO3-, and Sglt2 expression (p < 0.01). These responses were accompanied by >3-fold increases in the expression of phospho-ERK1/2 and the p65 subunit of NF-кB (p < 0.01). Losartan, U0126, or RO 106-9920 all significantly attenuated ECFP/Ang II-induced NHE3 and Na+/HCO3- expression (p < 0.01). Deletion of AT1 (AT1a) receptors in mPCT cells attenuated ECFP/Ang II-induced NHE3 and Na+/HCO3- expression (p < 0.01). Interestingly, the AT2 receptor blocker PD123319 also attenuated ECFP/Ang II-induced NHE3 and Na+/HCO3- expression (p < 0.01). These results suggest that, similar to extracellular Ang II, intracellular Ang II may also play an important role in Ang II receptor-mediated proximal tubule NHE3, Na+/HCO3-, and Sglt2 expression by activation of AT1a/MAPK/ERK1/2/NF-kB signaling pathways.
Collapse
Affiliation(s)
- Xiaochun Li
- Tulane Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, LA 70112-2699, USA;
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA 70112-2699, USA
| | - Jialong Zhuo
- Tulane Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, LA 70112-2699, USA;
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA 70112-2699, USA
| |
Collapse
|
37
|
Xiong L, Liu J, Han SY, Koppitch K, Guo JJ, Rommelfanger M, Gao F, Hallgrimsdottir IB, Pachter L, Kim J, MacLean AL, McMahon AP. Direct androgen receptor regulation of sexually dimorphic gene expression in the mammalian kidney. bioRxiv 2023:2023.05.06.539585. [PMID: 37205355 PMCID: PMC10187285 DOI: 10.1101/2023.05.06.539585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Mammalian organs exhibit distinct physiology, disease susceptibility and injury responses between the sexes. In the mouse kidney, sexually dimorphic gene activity maps predominantly to proximal tubule (PT) segments. Bulk RNA-seq data demonstrated sex differences were established from 4 and 8 weeks after birth under gonadal control. Hormone injection studies and genetic removal of androgen and estrogen receptors demonstrated androgen receptor (AR) mediated regulation of gene activity in PT cells as the regulatory mechanism. Interestingly, caloric restriction feminizes the male kidney. Single-nuclear multiomic analysis identified putative cis-regulatory regions and cooperating factors mediating PT responses to AR activity in the mouse kidney. In the human kidney, a limited set of genes showed conserved sex-linked regulation while analysis of the mouse liver underscored organ-specific differences in the regulation of sexually dimorphic gene expression. These findings raise interesting questions on the evolution, physiological significance, and disease and metabolic linkage, of sexually dimorphic gene activity.
Collapse
Affiliation(s)
- Lingyun Xiong
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Jing Liu
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Seung Yub Han
- Graduate Program in Genomics and Computational Biology, Biomedical Graduate Studies, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kari Koppitch
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Jin-Jin Guo
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
| | - Megan Rommelfanger
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Fan Gao
- Caltech Bioinformatics Resource Center at Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA
| | | | - Lior Pachter
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
- Department of Computing and Mathematical Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Junhyong Kim
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Adam L. MacLean
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Andrew P. McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089, USA
- Lead Contact
| |
Collapse
|
38
|
Wagner MC, Sandoval RM, Yadav SPS, Campos SB, Rhodes GJ, Phillips CL, Molitoris BA. Lrpap1 (RAP) Inhibits Proximal Tubule Clathrin Mediated and Clathrin Independent Endocytosis, Ameliorating Renal Aminoglycoside Nephrotoxicity. Kidney360 2023; 4:591-605. [PMID: 36848531 PMCID: PMC10278819 DOI: 10.34067/kid.0000000000000094] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 01/31/2023] [Indexed: 03/01/2023]
Abstract
Key Points Proximal tubule endocytosis of toxins often leads to nephrotoxicity. Inhibition of endocytosis with receptor-associated protein may serve as a clinical approach to reduce or eliminate kidney damage from a potential nephrotoxin. Background Proximal tubules (PTs) are exposed to many exogenous and endogenous nephrotoxins that pass through the glomerular filter. This includes many small molecules, such as aminoglycoside and myeloma light chains. These filtered molecules are rapidly endocytosed by the PTs and lead to nephrotoxicity. Methods To investigate whether inhibition of PT uptake of filtered toxins can reduce toxicity, we evaluated the ability of Lrpap1 or receptor-associated protein (RAP) to prevent PT endocytosis. Munich Wistar Frömter rats were used since both glomerular filtration and PT uptake can be visualized and quantified. The injury model chosen was the well-established gentamicin-induced toxicity, which leads to significant reductions in GFR and serum creatinine increases. CKD was induced with a right uninephrectomy and left 40-minute pedicle clamp. Rats had 8 weeks to recover and to stabilize GFR and proteinuria. Multiphoton microscopy was used to evaluate endocytosis in vivo and serum creatinine, and 24-hour creatinine clearances were used to evaluate kidney functional changes. Results Studies showed that preadministration of RAP significantly inhibited both albumin and dextran endocytosis in outer cortical PTs. Importantly, this inhibition was found to be rapidly reversible with time. RAP was also found to be an excellent inhibitor of PT gentamicin endocytosis. Finally, gentamicin administration for 6 days resulted in significant elevation of serum creatinine in vehicle-treated rats, but not in those receiving daily infusion of RAP before gentamicin. Conclusions This study provides a model for the potential use of RAP to prevent, in a reversible manner, PT endocytosis of potential nephrotoxins, thus protecting the kidney from damage.
Collapse
Affiliation(s)
- Mark C Wagner
- Indiana Center for Biological Microscopy, Indiana University School of Medicine, Indianapolis, Indiana
| | | | | | | | | | | | | |
Collapse
|
39
|
Chen L, Chou CL, Yang CR, Knepper MA. Multiomics Analyses Reveal Sex Differences in Mouse Renal Proximal Subsegments. J Am Soc Nephrol 2023; 34:829-845. [PMID: 36758122 PMCID: PMC10125651 DOI: 10.1681/asn.0000000000000089] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/04/2023] [Indexed: 02/11/2023] Open
Abstract
SIGNIFICANCE STATEMENT Sex-dependent differences in kidney function are recognized but the underlying molecular mechanisms are largely unexplored. Advances in genomics and proteomic technologies now allow extensive characterization of differences between the same cell types of males and females. Multiomics integrating RNA-seq, ATAC-seq, and proteomics data to investigate differences in gene expression, chromatin accessibility, and protein expression in proximal tubules of male and female mice identified many sex-biased genes and proteins associated with kidney functions, including metabolic and transport processes. Sex differences may also arise from variations of the interaction between transcription factors and accessible chromatin regions. A comprehensive web resource is provided to advance understanding of sex differences in cells of the proximal tubule. BACKGROUND Sex differences have been increasingly recognized as important in kidney physiology and pathophysiology, but limited resources are available for comprehensive interrogation of sex differences. METHODS RNA-seq and ATAC-seq of microdissected mouse proximal tubules and protein mass spectrometry of homogenized perfused mouse kidneys reveal differences in proximal tubule cells of males and females. RESULTS The transcriptomic data indicated that the major differences in the proximal tubules between the sexes were in the S2/S3 segments, and most of the sex-biased transcripts mapped to autosomes rather than to the sex chromosomes. Many of the transcripts exhibiting sex-biased expression are involved in monocarboxylic acid metabolic processes, organic anion transport, and organic acid transport. The ATAC-seq method on microdissected tubules captured chromatin accessibility. Many of the more than 7000 differentially accessible DNA regions identified were in distal regions. Motif analyses revealed a lack of direct involvement of estrogen receptors or the androgen receptor (absence of canonical hormone response elements), suggesting an indirect regulatory role of sex hormones. Instead, analyses identified several transcription factors (TFs) ( Tead1 , Nfia/b , and Pou3f3 ) whose interplay with proximal tubule-specific TFs ( e.g. , Hnf1b , Hnf4a ) may contribute to sex differences. Finally, the whole-kidney proteome was correlated with the transcriptome, and many sex-biased proteins ( e.g. , Cyp2e1, Acsm2/3) were identified. CONCLUSIONS Sex-dependent cis-regulatory elements interact with TFs in ways that lead to sex-biased gene expression in proximal tubule cells. These data are provided as a user-friendly web page at https://esbl.nhlbi.nih.gov/MRECA/PT/ .
Collapse
Affiliation(s)
- Lihe Chen
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | | | | | | |
Collapse
|
40
|
Mukherji ST, Brambilla L, Stuart KB, Mayes I, Kutz LC, Chen Y, Barbosa LA, Elmadbouh I, McDermott JP, Haller ST, Romero MF, Soleimani M, Liu J, Shapiro JI, Blanco GV, Xie Z, Pierre SV. Na/K-ATPase signaling tonically inhibits sodium reabsorption in the renal proximal tubule. FASEB J 2023; 37:e22835. [PMID: 36856735 PMCID: PMC10028530 DOI: 10.1096/fj.202200785rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 03/02/2023]
Abstract
Through its classic ATP-dependent ion-pumping function, basolateral Na/K-ATPase (NKA) generates the Na+ gradient that drives apical Na+ reabsorption in the renal proximal tubule (RPT), primarily through the Na+ /H+ exchanger (NHE3). Accordingly, activation of NKA-mediated ion transport decreases natriuresis through activation of basolateral (NKA) and apical (NHE3) Na+ reabsorption. In contrast, activation of the more recently discovered NKA signaling function triggers cellular redistribution of RPT NKA and NHE3 and decreases Na+ reabsorption. We used gene targeting to test the respective contributions of NKA signaling and ion pumping to the overall regulation of RPT Na+ reabsorption. Knockdown of RPT NKA in cells and mice increased membrane NHE3 and Na+ /HCO3 - cotransporter (NBCe1A). Urine output and absolute Na+ excretion decreased by 65%, driven by increased RPT Na+ reabsorption (as indicated by decreased lithium clearance and unchanged glomerular filtration rate), and accompanied by elevated blood pressure. This hyper reabsorptive phenotype was rescued upon crossing with RPT NHE3-/- mice, confirming the importance of NKA/NHE3 coupling. Hence, NKA signaling exerts a tonic inhibition on Na+ reabsorption by regulating key apical and basolateral Na+ transporters. This action, lifted upon NKA genetic suppression, tonically counteracts NKA's ATP-driven function of basolateral Na+ reabsorption. Strikingly, NKA signaling is not only physiologically relevant but it also appears to be functionally dominant over NKA ion pumping in the control of RPT reabsorption.
Collapse
Affiliation(s)
- Shreya T. Mukherji
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
| | - Luca Brambilla
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
| | - Kailey B. Stuart
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
| | - Isabella Mayes
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
| | - Laura C. Kutz
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
| | - Yiliang Chen
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
- Blood Research Institute, Versiti, WI
| | - Leandro A Barbosa
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
- Universidade Federal de São João del-Rei, Campus Centro-Oeste Dona Lindu, Divinópolis, MG, Brazil
| | - Ibrahim Elmadbouh
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
| | - Jeff P. McDermott
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS
| | - Steven T. Haller
- Department of Medicine, University of Toledo College of Medicine and Life Sciences, Toledo, OH
| | - Michael F. Romero
- Physiology & Biomedical Engineering and Nephrology & Hypertension, Mayo Clinic College of Medicine & Science, Rochester, MN
| | - Manoocher Soleimani
- Department of Medicine, The University of New Mexico Health Sciences Center, Albuquerque, NM
| | - Jiang Liu
- Joan C. Edwards School of Medicine, Marshall University, Huntington, WV
| | - Joseph I. Shapiro
- Joan C. Edwards School of Medicine, Marshall University, Huntington, WV
| | - Gustavo V. Blanco
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS
| | - Zijian Xie
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
| | - Sandrine V. Pierre
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
| |
Collapse
|
41
|
Shipman KE, Baty CJ, Long KR, Rbaibi Y, Cowan IA, Gerges M, Marciszyn AL, Kashlan OB, Tan RJ, Edwards A, Weisz OA. Impaired Endosome Maturation Mediates Tubular Proteinuria in Dent Disease Cell Culture and Mouse Models. J Am Soc Nephrol 2023; 34:619-640. [PMID: 36758125 PMCID: PMC10103310 DOI: 10.1681/asn.0000000000000084] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 01/03/2023] [Indexed: 02/11/2023] Open
Abstract
SIGNIFICANCE STATEMENT Loss of function of the 2Cl - /H + antiporter ClC-5 in Dent disease causes an unknown impairment in endocytic traffic, leading to tubular proteinuria. The authors integrated data from biochemical and quantitative imaging studies in proximal tubule cells into a mathematical model to determine that loss of ClC-5 impairs endosome acidification and delays early endosome maturation in proximal tubule cells, resulting in reduced megalin recycling, surface expression, and half-life. Studies in a Dent mouse model also revealed subsegment-specific differences in the effects of ClC-5 knockout on proximal tubule subsegments. The approach provides a template to dissect the effects of mutations or perturbations that alter tubular recovery of filtered proteins from the level of individual cells to the entire proximal tubule axis. BACKGROUND Loss of function of the 2Cl - /H + antiporter ClC-5 in Dent disease impairs the uptake of filtered proteins by the kidney proximal tubule, resulting in tubular proteinuria. Reduced posttranslational stability of megalin and cubilin, the receptors that bind to and recover filtered proteins, is believed to underlie the tubular defect. How loss of ClC-5 leads to reduced receptor expression remains unknown. METHODS We used biochemical and quantitative imaging data to adapt a mathematical model of megalin traffic in ClC-5 knockout and control cells. Studies in ClC-5 knockout mice were performed to describe the effect of ClC-5 knockout on megalin traffic in the S1 segment and along the proximal tubule axis. RESULTS The model predicts that ClC-5 knockout cells have reduced rates of exit from early endosomes, resulting in decreased megalin recycling, surface expression, and half-life. Early endosomes had lower [Cl - ] and higher pH. We observed more profound effects in ClC-5 knockout cells expressing the pathogenic ClC-5 E211G mutant. Alterations in the cellular distribution of megalin in ClC-5 knockout mice were consistent with delayed endosome maturation and reduced recycling. Greater reductions in megalin expression were observed in the proximal tubule S2 cells compared with S1, with consequences to the profile of protein retrieval along the proximal tubule axis. CONCLUSIONS Delayed early endosome maturation due to impaired acidification and reduced [Cl - ] accumulation is the primary mediator of reduced proximal tubule receptor expression and tubular proteinuria in Dent disease. Rapid endosome maturation in proximal tubule cells is critical for the efficient recovery of filtered proteins.
Collapse
Affiliation(s)
- Katherine E. Shipman
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Catherine J. Baty
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Kimberly R. Long
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Youssef Rbaibi
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Isabella A. Cowan
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Mona Gerges
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Allison L. Marciszyn
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Ossama B. Kashlan
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Roderick J. Tan
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Aurélie Edwards
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Ora A. Weisz
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| |
Collapse
|
42
|
Bingham MA, Neijman K, Yang CR, Aponte A, Mak A, Kikuchi H, Jung HJ, Poll BG, Raghuram V, Park E, Chou CL, Chen L, Leipziger J, Knepper MA, Dona M. Circadian gene expression in mouse renal proximal tubule. Am J Physiol Renal Physiol 2023; 324:F301-F314. [PMID: 36727945 PMCID: PMC9988533 DOI: 10.1152/ajprenal.00231.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 01/18/2023] [Accepted: 01/26/2023] [Indexed: 02/03/2023] Open
Abstract
Circadian variability in kidney function is well recognized but is often ignored as a potential confounding variable in physiological experiments. Here, we have created a data resource consisting of expression levels for mRNA transcripts in microdissected proximal tubule segments from mice as a function of the time of day. Small-sample RNA sequencing was applied to microdissected S1 proximal convoluted tubules and S2 proximal straight tubules. After stringent filtering, the data were analyzed using JTK-Cycle to detect periodicity. The data set is provided as a user-friendly webpage at https://esbl.nhlbi.nih.gov/Databases/Circadian-Prox2/. In proximal convoluted tubules, 234 transcripts varied in a circadian manner (4.0% of the total). In proximal straight tubules, 334 transcripts varied in a circadian manner (5.3%). Transcripts previously known to be associated with corticosteroid action and with increased flow were found to be overrepresented among circadian transcripts peaking during the "dark" portion of the day [zeitgeber time (ZT)14-22], corresponding to peak levels of corticosterone and glomerular filtration rate in mice. To ask whether there is a time-of-day dependence of protein abundances in the kidney, we carried out LC-MS/MS-based proteomics in whole mouse kidneys at ZT12 and ZT0. The full data set (n = 6,546 proteins) is available at https://esbl.nhlbi.nih.gov/Databases/Circadian-Proteome/. Overall, 293 proteins were differentially expressed between ZT12 and ZT0 (197 proteins greater at ZT12 and 96 proteins greater at ZT0). Among the regulated proteins, only nine proteins were found to be periodic in the RNA-sequencing analysis, suggesting a high level of posttranscriptional regulation of protein abundances.NEW & NOTEWORTHY Circadian variation in gene expression can be an important determinant in the regulation of kidney function. The authors used RNA-sequencing transcriptomics and LC-MS/MS-based proteomics to identify gene products expressed in a periodic manner. The data were used to construct user-friendly web resources.
Collapse
Affiliation(s)
- Molly A Bingham
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Kim Neijman
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chin-Rang Yang
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Angel Aponte
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Angela Mak
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Hiroaki Kikuchi
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Hyun Jun Jung
- Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Brian G Poll
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Viswanathan Raghuram
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Euijung Park
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Chung-Lin Chou
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Lihe Chen
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Jens Leipziger
- Department of Biomedicine, Physiology, Aarhus University, Aarhus, Denmark
| | - Mark A Knepper
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Margo Dona
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
43
|
Just A, Mallmann RT, Grossmann S, Sleman F, Klugbauer N. Two-pore channel protein TPC1 is a determining factor for the adaptation of proximal tubular phosphate handling. Acta Physiol (Oxf) 2023; 237:e13914. [PMID: 36599408 DOI: 10.1111/apha.13914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 10/27/2022] [Accepted: 01/02/2023] [Indexed: 01/06/2023]
Abstract
AIM Two-pore channels (TPCs) constitute a small family of cation channels expressed in endo-lysosomal compartments. TPCs have been characterized as critical elements controlling Ca2+ -mediated vesicular membrane fusion and thereby regulating endo-lysosomal vesicle trafficking. Exo- and endocytotic trafficking and lysosomal degradation are major mechanisms of adaption of epithelial transport. A prime example of highly regulated epithelial transport is the tubular system of the kidney. We therefore studied the localization of TPC protein 1 (TPC1) in the kidney and its functional role in the dynamic regulation of tubular transport. METHODS Immunohistochemistry in combination with tubular markers were used to investigate TPC1 expression in proximal and distal tubules. The excretion of phosphate and ammonium, as well as urine volume and pH were studied in vivo, in response to dynamic challenges induced by bolus injection of parathyroid hormone or acid-base transitions via consecutive infusion of NaCl, Na2 CO3 , and NH4 Cl. RESULTS In TPC1-deficient mice, the PTH-induced rise in phosphate excretion was prolonged and exaggerated, and its recovery delayed in comparison with wildtype littermates. In the acid-base transition experiment, TPC1-deficient mice showed an identical rise in phosphate excretion in response to Na2 CO3 compared with wildtypes, but a delayed NH4Cl-induced recovery. Ammonium-excretion decreased with Na2 CO3 , and increased with NH4 Cl, but without differences between genotypes. CONCLUSIONS We conclude that TPC1 is expressed subapically in the proximal but not distal tubule and plays an important role in the dynamic adaptation of proximal tubular phosphate reabsorption towards enhanced, but not reduced absorption.
Collapse
Affiliation(s)
- Armin Just
- Institut für Physiologie I, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Robert T Mallmann
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Sonja Grossmann
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Faten Sleman
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Norbert Klugbauer
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| |
Collapse
|
44
|
Shin S, Boadi EA, Bandyopadhyay BC. Ablation of TRPC3 compromises bicarbonate and phosphate transporter activity in mice proximal tubular cells. Clin Exp Pharmacol Physiol 2023; 50:247-255. [PMID: 36433745 PMCID: PMC10258833 DOI: 10.1111/1440-1681.13741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 11/19/2022] [Accepted: 11/21/2022] [Indexed: 11/28/2022]
Abstract
Proximal tubular (PT) cells reabsorb most calcium (Ca2+ ), phosphate (PO4 3- ), bicarbonate (HCO3 - ), and oxalate (C2 O4 2- ) ions. We have shown that mice lacking Transient Receptor Potential Canonical 3 (TRPC3-/- ) channel are moderately hypercalciuric with presentation of luminal calcium phosphate (CaP) crystals at the loop of Henle (LOH). However, other predisposing factors for such crystal deposition are unknown. Thus, we examined the distinctions in functional status of HCO3 - , PO4 3- , and C2 O4 2- transporters in PT cells of wild type (WT) and TRPC3-/- mice by whole-cell patch clamp techniques to assess their contribution in the development of LOH CaP crystals. Here we show the development of concentration dependent HCO3 - -induced currents in all PT cells, which was confirmed by using specific HCO3 - channel inhibitor, S0859. Interestingly, such activities were diminished in PT cells from TRPC3-/- mice, suggesting reduced HCO3 - transport in absence of TRPC3. While PO4 3- -induced currents were also concentration dependent in all PT cells (confirmed by PO4 3- channel inhibitor, PF-06869206), those activities were reduced in absence of TRPC3, suggesting lower PO4 3- reabsorption that can leave excess luminal PO4 3- . Next, we applied thiosulfate (O3 S2 2 - ) as a competitive inhibitor of the SLC26a6 transporter upon C2 O4 2- current activation and observed a reduced C2 O4 2- -induced conductance which was greater in TRPC3-/- PT cells. Together, these results suggest that the reduced activities of HCO3 - , PO4 3- , and C2 O4 2- transporters in moderately hypercalciuric (TRPC3-/- ) PT cells can create a predisposing condition for CaP and CaP tubular crystallization, enabling CaP crystal formation in LOH of TRPC3-/- mice.
Collapse
Affiliation(s)
- Samuel Shin
- Calcium Signaling Laboratory, Research Service, Veterans Affairs Medical Center, Washington, Columbia, USA
| | - Eugenia Awuah Boadi
- Calcium Signaling Laboratory, Research Service, Veterans Affairs Medical Center, Washington, Columbia, USA
| | - Bidhan C. Bandyopadhyay
- Calcium Signaling Laboratory, Research Service, Veterans Affairs Medical Center, Washington, Columbia, USA
- Division of Renal Diseases & Hypertension, Department of Medicine, The George Washington University, Washington, Columbia, USA
| |
Collapse
|
45
|
Biancalana E, Rossi C, Raggi F, Distaso M, Tricò D, Baldi S, Ferrannini E, Solini A. Empagliflozin and renal sodium-hydrogen exchange in healthy subjects. J Clin Endocrinol Metab 2023:7041118. [PMID: 36794422 DOI: 10.1210/clinem/dgad088] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/25/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023]
Abstract
CONTEXT Sodium glucose co-transporter-2 inhibitors (SGLT2i) exert clinically relevant cardiorenal protection. Among several mechanisms, inhibition of the sodium-hydrogen exchanger-3 (NHE3) in proximal renal tubules has been proposed in rodents. Demonstration of this mechanism with the associated electrolyte and metabolic changes in humans is lacking. OBJECTIVE The present proof-of-concept study was designed to explore the involvement of NHE3 in modulating the response to SGLT2i in humans. METHODS Twenty healthy male volunteers received two tablets of empagliflozin 25 mg during a standardized hydration scheme; freshly voided urines and blood samples were collected at timed intervals for 8 hours. Protein expression of relevant transporters was examined in exfoliated tubular cells. RESULTS Urine pH increased after empagliflozin (from 5.81 ± 0.5 to 6.16 ± 0.6 at 6 hours, p = 0.008) as did urinary output (from 1.7 [0.6; 2.5] to 2.5 [1.7; 3.5] mL.min-1, p = 0.008) and glucose (from 0.03 [0.02; 0.04] to 34.8 [31.6; 40.2] %, p < 0.0001) and sodium fractional excretion rates (from 0.48 [0.34; 0.65] to 0.71 [0.55; 0.85] %, p = 0.0001), while plasma glucose and insulin concentrations decreased and plasma and urinary ketones increased. Non-significant changes in NHE3, pNHE3 and MAP17 protein expression were detected in urinary exfoliated tubular cells. In a time-control study in 6 participants, neither urine pH nor plasma and urinary parameters changed. CONCLUSIONS In healthy young volunteers, empagliflozin acutely increases urinary pH while inducing a substrate shift towards lipid utilization and ketogenesis, without significant changes in renal NHE3 protein expression.
Collapse
Affiliation(s)
- Edoardo Biancalana
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - Chiara Rossi
- Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Italy
| | - Francesco Raggi
- Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Italy
| | - Mariarosaria Distaso
- Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Italy
| | - Domenico Tricò
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - Simona Baldi
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - Ele Ferrannini
- Consiglio Nazionale delle Ricerche (CNR) Institute of Clinical Physiology, Pisa, Italy
| | - Anna Solini
- Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Italy
| |
Collapse
|
46
|
Eymael J, van den Broek M, Miesen L, Monge VV, van den Berge BT, Mooren F, Velez VL, Dijkstra J, Hermsen M, Bándi P, Vermeulen M, de Wildt S, Willemsen B, Florquin S, Wetzels R, Steenbergen E, Kramann R, Moeller M, Schreuder MF, Wetzels JF, van der Vlag J, Jansen J, Smeets B. Human scattered tubular cells represent a heterogeneous population of glycolytic dedifferentiated proximal tubule cells. J Pathol 2023; 259:149-162. [PMID: 36373978 PMCID: PMC10107692 DOI: 10.1002/path.6029] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/22/2022] [Accepted: 10/31/2022] [Indexed: 11/16/2022]
Abstract
Scattered tubular cells (STCs) are a phenotypically distinct cell population in the proximal tubule that increase in number after acute kidney injury. We aimed to characterize the human STC population. Three-dimensional human tissue analysis revealed that STCs are preferentially located within inner bends of the tubule and are barely present in young kidney tissue (<2 years), and their number increases with age. Increased STC numbers were associated with acute tubular injury (kidney injury molecule 1) and interstitial fibrosis (alpha smooth muscle actin). Isolated CD13+ CD24- CD133- proximal tubule epithelial cells (PTECs) and CD13+ CD24+ and CD13+ CD133+ STCs were analyzed using RNA sequencing. Transcriptome analysis revealed an upregulation of nuclear factor κB, tumor necrosis factor alpha, and inflammatory pathways in STCs, whereas metabolism, especially the tricarboxylic acid cycle and oxidative phosphorylation, was downregulated, without showing signs of cellular senescence. Using immunostaining and a publicly available single-cell sequencing database of human kidneys, we demonstrate that STCs represent a heterogeneous population in a transient state. In conclusion, STCs are dedifferentiated PTECs showing a metabolic shift toward glycolysis, which could facilitate cellular survival after kidney injury. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
Collapse
Affiliation(s)
- Jennifer Eymael
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Martijn van den Broek
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Laura Miesen
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Valerie Villacorta Monge
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bartholomeus T van den Berge
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Fieke Mooren
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Vicky Luna Velez
- Department of Molecular Biology, Radboud Institute for Molecular Life Science, Nijmegen, The Netherlands
| | - Jelmer Dijkstra
- Department of Molecular Biology, Radboud Institute for Molecular Life Science, Nijmegen, The Netherlands
| | - Meyke Hermsen
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Péter Bándi
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Michiel Vermeulen
- Department of Molecular Biology, Radboud Institute for Molecular Life Science, Nijmegen, The Netherlands
| | - Saskia de Wildt
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Science, Nijmegen, The Netherlands
| | - Brigith Willemsen
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Sandrine Florquin
- Department of Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Amsterdam Institute for Infection and Immunology, Amsterdam, The Netherlands
| | - Roy Wetzels
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Eric Steenbergen
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rafael Kramann
- Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany.,Institute of Experimental Medicine and Systems Biology, RWTH Aachen University, Aachen, Germany.,Department of Internal Medicine, Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Marcus Moeller
- Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany
| | - Michiel F Schreuder
- Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Jack Fm Wetzels
- Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Nephrology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Johan van der Vlag
- Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jitske Jansen
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Amalia Children's Hospital, Nijmegen, The Netherlands.,Institute of Experimental Medicine and Systems Biology, RWTH Aachen University, Aachen, Germany
| | - Bart Smeets
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
47
|
Koch B, Fuhrmann DC, Schubert R, Geiger H, Speer T, Baer PC. Gliflozins Have an Anti-Inflammatory Effect on Renal Proximal Tubular Epithelial Cells in a Diabetic and Inflammatory Microenvironment In Vitro. Int J Mol Sci 2023; 24. [PMID: 36768138 DOI: 10.3390/ijms24031811] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/04/2023] [Accepted: 01/14/2023] [Indexed: 01/18/2023] Open
Abstract
Inflammation is intimately involved in the pathogenesis of diabetic kidney disease. Inhibition of SGLT-2 by a specific class of drugs, gliflozins, has been shown to reduce inflammation and attenuate the progression of diabetic nephropathy, in addition to its main effect of inhibiting renal glucose reabsorption. We used highly purified human renal proximal tubular epithelial cells (PTCs) as an in vitro model to study the cellular response to a diabetic (high glucose) and inflammatory (cytokines) microenvironment and the effect of gliflozins. In this context, we investigated the influence of SGLT-2 inhibition by empa- and dapagliflozin (500 nM) on the expression of pro-inflammatory factors (IL-1β, IL-6, TNF-α, MCP-1, and ICAM-1). The results clearly indicate an anti-inflammatory effect of both gliflozins. Although induced expression of the four cytokines was only slightly attenuated, there was a clear effect on the expression of the adhesion molecule ICAM-1, a master regulator of cellular responses in inflammation and injury resolution. The induced expression of ICAM-1 mRNA was significantly reduced by approximately 13.5% by empagliflozin and also showed an inhibitory trend with dapagliflozin. However, induced ICAM-1 protein expression was significantly inhibited from 24.71 ± 1.0 ng/mL to 18.81 ± 3.9 (empagliflozin) and 19.62 ± 2.1 ng/mL (dapagliflozin). In conclusion, an additional anti-inflammatory effect of empa- and dapagliflozin in therapeutically observed concentrations was demonstrated in primary human PTCs in vitro.
Collapse
|
48
|
Lee SK, Occhipinti R, Moss FJ, Parker MD, Grichtchenko II, Boron WF. Distinguishing among HCO 3- , CO 3= , and H + as Substrates of Proteins That Appear To Be "Bicarbonate" Transporters. J Am Soc Nephrol 2023; 34:40-54. [PMID: 36288904 PMCID: PMC10103014 DOI: 10.1681/asn.2022030289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 07/23/2022] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Differentiating among HCO 3- , CO 3= , and H + movements across membranes has long seemed impossible. We now seek to discriminate unambiguously among three alternate mechanisms: the inward flux of 2 HCO 3- (mechanism 1), the inward flux of 1 CO 3= (mechanism 2), and the CO 2 /HCO 3- -stimulated outward flux of 2 H + (mechanism 3). METHODS As a test case, we use electrophysiology and heterologous expression in Xenopus oocytes to examine SLC4 family members that appear to transport "bicarbonate" ("HCO 3- "). RESULTS First, we note that cell-surface carbonic anhydrase should catalyze the forward reaction CO 2 +OH - →HCO 3- if HCO 3- is the substrate; if it is not, the reverse reaction should occur. Monitoring changes in cell-surface pH ( Δ pH S ) with or without cell-surface carbonic anhydrase, we find that the presumed Cl-"HCO 3 " exchanger AE1 (SLC4A1) does indeed transport HCO 3- (mechanism 1) as long supposed, whereas the electrogenic Na/"HCO 3 " cotransporter NBCe1 (SLC4A4) and the electroneutral Na + -driven Cl-"HCO 3 " exchanger NDCBE (SLC4A8) do not. Second, we use mathematical simulations to show that each of the three mechanisms generates unique quantities of H + at the cell surface (measured as Δ pH S ) per charge transported (measured as change in membrane current, ΔIm ). Calibrating ΔpH S /Δ Im in oocytes expressing the H + channel H V 1, we find that our NBCe1 data align closely with predictions of CO 3= transport (mechanism 2), while ruling out HCO 3- (mechanism 1) and CO 2 /HCO 3- -stimulated H + transport (mechanism 3). CONCLUSIONS Our surface chemistry approach makes it possible for the first time to distinguish among HCO 3- , CO 3= , and H + fluxes, thereby providing insight into molecular actions of clinically relevant acid-base transporters and carbonic-anhydrase inhibitors.
Collapse
Affiliation(s)
- Seong-Ki Lee
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Rossana Occhipinti
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Fraser J. Moss
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Mark D. Parker
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio
- Department of Physiology and Biophysics, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York
| | | | - Walter F. Boron
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio
| |
Collapse
|
49
|
Verlander JW, Lee HW, Wall SM, Harris AN, Weiner ID. The proximal tubule through an NBCe1-dependent mechanism regulates collecting duct phenotypic and remodeling responses to acidosis. Am J Physiol Renal Physiol 2023; 324:F12-F29. [PMID: 36264886 PMCID: PMC9762982 DOI: 10.1152/ajprenal.00175.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 02/04/2023] Open
Abstract
The renal response to acid-base disturbances involves phenotypic and remodeling changes in the collecting duct. This study examines whether the proximal tubule controls these responses. We examined mice with genetic deletion of proteins present only in the proximal tubule, either the A variant or both A and B variants of isoform 1 of the electrogenic Na+-bicarbonate cotransporter (NBCe1). Both knockout (KO) mice have spontaneous metabolic acidosis. We then determined the collecting duct phenotypic responses to this acidosis and the remodeling responses to exogenous acid loading. Despite the spontaneous acidosis in NBCe1-A KO mice, type A intercalated cells in the inner stripe of the outer medullary collecting duct (OMCDis) exhibited decreased height and reduced expression of H+-ATPase, anion exchanger 1, Rhesus B glycoprotein, and Rhesus C glycoprotein. Combined kidney-specific NBCe1-A/B deletion induced similar changes. Ultrastructural imaging showed decreased apical plasma membrane and increased vesicular H+-ATPase in OMCDis type A intercalated cell in NBCe1-A KO mice. Next, we examined the collecting duct remodeling response to acidosis. In wild-type mice, acid loading increased the proportion of type A intercalated cells in the connecting tubule (CNT) and OMCDis, and it decreased the proportion of non-A, non-B intercalated cells in the connecting tubule, and type B intercalated cells in the cortical collecting duct (CCD). These changes were absent in NBCe1-A KO mice. We conclude that the collecting duct phenotypic and remodeling responses depend on proximal tubule-dependent signaling mechanisms blocked by constitutive deletion of proximal tubule NBCe1 proteins.NEW & NOTEWORTHY This study shows that the proximal tubule regulates collecting duct phenotypic and remodeling responses to acidosis.
Collapse
Affiliation(s)
- Jill W Verlander
- Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Hyun-Wook Lee
- Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Susan M Wall
- Renal Division, Emory University, Atlanta, Georgia
| | - Autumn N Harris
- Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
- Deparment of Small Animal Clinical Science, University of Florida College of Veterinary Medicine, Gainesville, Florida
| | - I David Weiner
- Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
- Nephrology and Hypertension Section, Gainesville Veterans Administration Medical Center, Gainesville, Florida
| |
Collapse
|
50
|
Chu PL, Gigliotti JC, Cechova S, Bodonyi-Kovacs G, Wang YT, Chen L, Wassertheil-Smoller S, Cai J, Isakson BE, Franceschini N, Le TH. Collectrin ( Tmem27) deficiency in proximal tubules causes hypertension in mice and a TMEM27 variant associates with blood pressure in males in a Latino cohort. Am J Physiol Renal Physiol 2023; 324:F30-F42. [PMID: 36264884 PMCID: PMC9762972 DOI: 10.1152/ajprenal.00176.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/07/2022] [Accepted: 09/23/2022] [Indexed: 02/04/2023] Open
Abstract
Collectrin (Tmem27), an angiotensin-converting enzyme 2 homologue, is a chaperone of amino acid transporters in the kidney and endothelium. Global collectrin knockout (KO) mice have hypertension, endothelial dysfunction, exaggerated salt sensitivity, and diminished renal blood flow. This phenotype is associated with altered nitric oxide and superoxide balance and increased proximal tubule (PT) Na+/H+ exchanger isoform 3 (NHE3) expression. Collectrin is located on the X chromosome where genome-wide association population studies have largely been excluded. In the present study, we generated PT-specific collectrin KO (PT KO) mice to determine the precise contribution of PT collectrin in blood pressure homeostasis. We also examined the association of human TMEM27 single-nucleotide polymorphisms with blood pressure traits in 11,926 Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Hispanic/Latino participants. PT KO mice exhibited hypertension, and this was associated with increased baseline NHE3 expression and diminished lithium excretion. However, PT KO mice did not display exaggerated salt sensitivity or a reduction in renal blood flow compared with control mice. Furthermore, PT KO mice exhibited enhanced endothelium-mediated dilation, suggesting a compensatory response to systemic hypertension induced by deficiency of collectrin in the PT. In HCHS/SOL participants, we observed sex-specific single-nucleotide polymorphism associations with diastolic blood pressure. In conclusion, loss of collectrin in the PT is sufficient to induce hypertension, at least in part, through activation of NHE3. Importantly, our model supports the notion that altered renal blood flow may be a determining factor for salt sensitivity. Further studies are needed to investigate the role of the TMEM27 locus on blood pressure and salt sensitivity in humans.NEW & NOTEWORTHY The findings of our study are significant in several ways: 1) loss of an amino acid chaperone in the proximal tubule is sufficient to cause hypertension, 2) the results in global and proximal tubule-specific collectrin knockout mice support the notion that vascular dysfunction is required for salt sensitivity or that impaired renal tubule function causes hypertension but is not sufficient to cause salt sensitivity, and 3) our study is the first to implicate a role of collectrin in human hypertension.
Collapse
Affiliation(s)
- Pei-Lun Chu
- Division of Nephrology, Fu Jen Catholic University Hospital, and School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Joseph C Gigliotti
- Department of Integrated Physiology and Pharmacology, Liberty University College of Osteopathic Medicine, Lynchburg, Virginia
| | - Sylvia Cechova
- Division of Nephrology, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia
| | - Gabor Bodonyi-Kovacs
- Division of Nephrology, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia
| | - Yves T Wang
- Division of Nephrology, Department of Medicine, University of Rochester Medical Center Rochester, Rochester, New York
| | - Luojing Chen
- Division of Nephrology, Department of Medicine, University of Rochester Medical Center Rochester, Rochester, New York
| | - Sylvia Wassertheil-Smoller
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York
| | - Jianwen Cai
- Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Center and Department of Molecular Physiology and Biophysics, University of Virginia Health System, Charlottesville, Virginia
| | - Nora Franceschini
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina
| | - Thu H Le
- Division of Nephrology, Department of Medicine, University of Rochester Medical Center Rochester, Rochester, New York
| |
Collapse
|