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Cunanan J, Rajyam SS, Sharif B, Udwan K, Rana A, De Gregorio V, Ricardo S, Elia A, Brooks B, Weins A, Pollak M, John R, Barua M. Mice with a Pax2 missense variant display impaired glomerular repair. Am J Physiol Renal Physiol 2024; 326:F704-F726. [PMID: 38482556 DOI: 10.1152/ajprenal.00259.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 03/01/2024] [Accepted: 03/01/2024] [Indexed: 04/26/2024] Open
Abstract
PAX2 regulates kidney development, and its expression persists in parietal epithelial cells (PECs), potentially serving as a podocyte reserve. We hypothesized that mice with a Pax2 pathogenic missense variant (Pax2A220G/+) have impaired PEC-mediated podocyte regeneration. Embryonic wild-type mouse kidneys showed overlapping expression of PAX2/Wilms' tumor-1 (WT-1) until PEC and podocyte differentiation, reflecting a close lineage relationship. Embryonic and adult Pax2A220G/+ mice have reduced nephron number but demonstrated no glomerular disease under baseline conditions. Pax2A220G/+ mice compared with wild-type mice were more susceptible to glomerular disease after adriamycin (ADR)-induced podocyte injury, as demonstrated by worsened glomerular scarring, increased podocyte foot process effacement, and podocyte loss. There was a decrease in PAX2-expressing PECs in wild-type mice after adriamycin injury accompanied by the occurrence of PAX2/WT-1-coexpressing glomerular tuft cells. In contrast, Pax2A220G/+ mice showed no changes in the numbers of PAX2-expressing PECs after adriamycin injury, associated with fewer PAX2/WT-1-coexpressing glomerular tuft cells compared with injured wild-type mice. A subset of PAX2-expressing glomerular tuft cells after adriamycin injury was increased in Pax2A220G/+ mice, suggesting a pathological process given the worse outcomes observed in this group. Finally, Pax2A220G/+ mice have increased numbers of glomerular tuft cells expressing Ki-67 and cleaved caspase-3 compared with wild-type mice after adriamycin injury, consistent with maladaptive responses to podocyte loss. Collectively, our results suggest that decreased glomerular numbers in Pax2A220G/+ mice are likely compounded with the inability of their mutated PECs to regenerate podocyte loss, and together these two mechanisms drive the worsened focal segmental glomerular sclerosis phenotype in these mice.NEW & NOTEWORTHY Congenital anomalies of the kidney and urinary tract comprise some of the leading causes of kidney failure in children, but our previous study showed that one of its genetic causes, PAX2, is also associated with adult-onset focal segmental glomerular sclerosis. Using a clinically relevant model, our present study demonstrated that after podocyte injury, parietal epithelial cells expressing PAX2 are deployed into the glomerular tuft to assist in repair in wild-type mice, but this mechanism is impaired in Pax2A220G/+ mice.
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Affiliation(s)
- Joanna Cunanan
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada
- Advanced Diagnostics Department, Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Ontario, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Sarada Sriya Rajyam
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada
- Advanced Diagnostics Department, Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Ontario, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Bedra Sharif
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada
- Advanced Diagnostics Department, Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Ontario, Canada
| | - Khalil Udwan
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada
- Advanced Diagnostics Department, Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Ontario, Canada
- Department of Pathology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Akanchaya Rana
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada
- Advanced Diagnostics Department, Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Ontario, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Vanessa De Gregorio
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada
- Advanced Diagnostics Department, Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Ontario, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Samantha Ricardo
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada
- Advanced Diagnostics Department, Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Ontario, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Elia
- Department of Pathology, Princess Margaret Hospital, Toronto, Ontario, Canada
| | - Brian Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Astrid Weins
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States
| | - Martin Pollak
- Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States
| | - Rohan John
- Department of Pathology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Moumita Barua
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada
- Advanced Diagnostics Department, Toronto General Hospital Research Institute, Toronto General Hospital, Toronto, Ontario, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
- Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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Akalay S, Rayyan M, Fidlers T, van den Heuvel L, Levtchenko E, Arcolino FO. Impact of preterm birth on kidney health and development. Front Med (Lausanne) 2024; 11:1363097. [PMID: 38601116 PMCID: PMC11004308 DOI: 10.3389/fmed.2024.1363097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 03/14/2024] [Indexed: 04/12/2024] Open
Abstract
Preterm birth, defined as birth before the gestational age of 37 weeks, affects 11% of the newborns worldwide. While extensive research has focused on the immediate complications associated with prematurity, emerging evidence suggests a link between prematurity and the development of kidney disease later in life. It has been demonstrated that the normal course of kidney development is interrupted in infants born prematurely, causing an overall decrease in functional nephrons. Yet, the pathogenesis leading to the alterations in kidney development and the subsequent pathophysiological consequences causing kidney disease on the long-term are incompletely understood. In the present review, we discuss the current knowledge on nephrogenesis and how this process is affected in prematurity. We further discuss the epidemiological evidence and experimental data demonstrating the increased risk of kidney disease in these individuals and highlight important knowledge gaps. Importantly, understanding the intricate interplay between prematurity, abnormal kidney development, and the long-term risk of kidney disease is crucial for implementing effective preventive and therapeutic strategies.
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Affiliation(s)
- Sara Akalay
- Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium
- Department of Nephrology, Dialysis and Renal Transplantation, University Hospitals Leuven, Leuven, Belgium
| | - Maissa Rayyan
- Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
| | - Tom Fidlers
- Department of Gynecologic Oncology, Oscar Lambret Cancer Center, Lille, France
| | - Lambertus van den Heuvel
- Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium
- Department of Pediatric Nephrology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Elena Levtchenko
- Department of Pediatric Nephrology, Emma Children’s Hospital, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Fanny Oliveira Arcolino
- Department of Pediatric Nephrology, Emma Children’s Hospital, Amsterdam University Medical Centers, Amsterdam, Netherlands
- Emma Center for Personalized Medicine, Amsterdam University Medical Centers, Amsterdam, Netherlands
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3
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Wang T, Shen W, Li L, Wang H, Zhang M, Chen X. Comparison of preparation methods of rat kidney single-cell suspensions. Sci Rep 2024; 14:2785. [PMID: 38307992 PMCID: PMC10837120 DOI: 10.1038/s41598-024-53270-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 01/30/2024] [Indexed: 02/04/2024] Open
Abstract
Preparation of kidney tissue single-cell suspensions is the basis of single-cell sequencing, flow cytometry and primary cell culture, but it is difficult to prepare high quality whole kidney single-cell suspensions because of the complex structure of the kidney. We explored a technique called stepwise enzymatic digestion (StE) method for preparing a single-cell suspension of rat whole kidney tissue which contained three main steps. The first step is to cut the kidney into a homogenate. The second step is the digestion of renal tubules using Multi Tissue Dissociation Kit 2 and the last step is the digestion of glomeruli using type IV collagenase. We also compared it with two previous techniques, mechanical grinding method and simple enzymatic digestion method. The StE method had the advantages of high intrinsic glomerular cells and immune cells harvest rate, high singlets rate and high cell viability compared with the other two techniques. In conclusion, the StE method is feasible, highly efficient, and worthy of further research and development.
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Affiliation(s)
- Tiantian Wang
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, National Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Military Logistics Research Key Laboratory of Field Disease Treatment, Beijing Key Laboratory of Kidney Disease Research, Beijing, 100853, China
| | - Wanjun Shen
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, National Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Military Logistics Research Key Laboratory of Field Disease Treatment, Beijing Key Laboratory of Kidney Disease Research, Beijing, 100853, China
| | - Lin Li
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, National Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Military Logistics Research Key Laboratory of Field Disease Treatment, Beijing Key Laboratory of Kidney Disease Research, Beijing, 100853, China
| | - Haoran Wang
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, National Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Military Logistics Research Key Laboratory of Field Disease Treatment, Beijing Key Laboratory of Kidney Disease Research, Beijing, 100853, China
| | - Min Zhang
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, National Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Military Logistics Research Key Laboratory of Field Disease Treatment, Beijing Key Laboratory of Kidney Disease Research, Beijing, 100853, China.
| | - Xiangmei Chen
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, National Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Military Logistics Research Key Laboratory of Field Disease Treatment, Beijing Key Laboratory of Kidney Disease Research, Beijing, 100853, China.
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Bane O, Seeliger E, Cox E, Stabinska J, Bechler E, Lewis S, Hickson LJ, Francis S, Sigmund E, Niendorf T. Renal MRI: From Nephron to NMR Signal. J Magn Reson Imaging 2023; 58:1660-1679. [PMID: 37243378 PMCID: PMC11025392 DOI: 10.1002/jmri.28828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
Renal diseases pose a significant socio-economic burden on healthcare systems. The development of better diagnostics and prognostics is well-recognized as a key strategy to resolve these challenges. Central to these developments are MRI biomarkers, due to their potential for monitoring of early pathophysiological changes, renal disease progression or treatment effects. The surge in renal MRI involves major cross-domain initiatives, large clinical studies, and educational programs. In parallel with these translational efforts, the need for greater (patho)physiological specificity remains, to enable engagement with clinical nephrologists and increase the associated health impact. The ISMRM 2022 Member Initiated Symposium (MIS) on renal MRI spotlighted this issue with the goal of inspiring more solutions from the ISMRM community. This work is a summary of the MIS presentations devoted to: 1) educating imaging scientists and clinicians on renal (patho)physiology and demands from clinical nephrologists, 2) elucidating the connection of MRI parameters with renal physiology, 3) presenting the current state of leading MR surrogates in assessing renal structure and functions as well as their next generation of innovation, and 4) describing the potential of these imaging markers for providing clinically meaningful renal characterization to guide or supplement clinical decision making. We hope to continue momentum of recent years and introduce new entrants to the development process, connecting (patho)physiology with (bio)physics, and conceiving new clinical applications. We envision this process to benefit from cross-disciplinary collaboration and analogous efforts in other body organs, but also to maximally leverage the unique opportunities of renal physiology. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 2.
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Affiliation(s)
- Octavia Bane
- Department of Diagnostic, Molecular and Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York City, New York, USA
- Icahn School of Medicine at Mount Sinai, BioMedical Engineering and Imaging Institute, New York City, New York, USA
| | - Erdmann Seeliger
- Institute of Translational Physiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Eleanor Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Julia Stabinska
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Eric Bechler
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sara Lewis
- Department of Diagnostic, Molecular and Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York City, New York, USA
| | - LaTonya J Hickson
- Division of Nephrology and Hypertension, Mayo Clinic, Jacksonville, Florida, USA
| | - Sue Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Eric Sigmund
- Bernard and Irene Schwartz Center for Biomedical Imaging Center for Advanced Imaging Innovation and Research (CAI2R), New York University Langone Health, New York City, New York, USA
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
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5
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Han Y, Zhang Z, Li Y, Fan G, Liang M, Liu Z, Nie S, Ning K, Luo Q, Yuan J. FastCellpose: A Fast and Accurate Deep-Learning Framework for Segmentation of All Glomeruli in Mouse Whole-Kidney Microscopic Optical Images. Cells 2023; 12:2753. [PMID: 38067181 PMCID: PMC10706842 DOI: 10.3390/cells12232753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Automated evaluation of all glomeruli throughout the whole kidney is essential for the comprehensive study of kidney function as well as understanding the mechanisms of kidney disease and development. The emerging large-volume microscopic optical imaging techniques allow for the acquisition of mouse whole-kidney 3D datasets at a high resolution. However, fast and accurate analysis of massive imaging data remains a challenge. Here, we propose a deep learning-based segmentation method called FastCellpose to efficiently segment all glomeruli in whole mouse kidneys. Our framework is based on Cellpose, with comprehensive optimization in network architecture and the mask reconstruction process. By means of visual and quantitative analysis, we demonstrate that FastCellpose can achieve superior segmentation performance compared to other state-of-the-art cellular segmentation methods, and the processing speed was 12-fold higher than before. Based on this high-performance framework, we quantitatively analyzed the development changes of mouse glomeruli from birth to maturity, which is promising in terms of providing new insights for research on kidney development and function.
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Affiliation(s)
- Yutong Han
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (Y.H.); (Z.Z.); (Y.L.); (G.F.); (M.L.); (S.N.); (K.N.); (Q.L.)
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- HUST-Suzhou Institute for Brainsmatics, JITRI Institute for Brainsmatics, Suzhou 215123, China
| | - Zhan Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (Y.H.); (Z.Z.); (Y.L.); (G.F.); (M.L.); (S.N.); (K.N.); (Q.L.)
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yafeng Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (Y.H.); (Z.Z.); (Y.L.); (G.F.); (M.L.); (S.N.); (K.N.); (Q.L.)
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- HUST-Suzhou Institute for Brainsmatics, JITRI Institute for Brainsmatics, Suzhou 215123, China
| | - Guoqing Fan
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (Y.H.); (Z.Z.); (Y.L.); (G.F.); (M.L.); (S.N.); (K.N.); (Q.L.)
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- HUST-Suzhou Institute for Brainsmatics, JITRI Institute for Brainsmatics, Suzhou 215123, China
| | - Mengfei Liang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (Y.H.); (Z.Z.); (Y.L.); (G.F.); (M.L.); (S.N.); (K.N.); (Q.L.)
| | - Zhijie Liu
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China;
| | - Shuo Nie
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (Y.H.); (Z.Z.); (Y.L.); (G.F.); (M.L.); (S.N.); (K.N.); (Q.L.)
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Kefu Ning
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (Y.H.); (Z.Z.); (Y.L.); (G.F.); (M.L.); (S.N.); (K.N.); (Q.L.)
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- HUST-Suzhou Institute for Brainsmatics, JITRI Institute for Brainsmatics, Suzhou 215123, China
| | - Qingming Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (Y.H.); (Z.Z.); (Y.L.); (G.F.); (M.L.); (S.N.); (K.N.); (Q.L.)
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- School of Biomedical Engineering, Hainan University, Haikou 570228, China
| | - Jing Yuan
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China; (Y.H.); (Z.Z.); (Y.L.); (G.F.); (M.L.); (S.N.); (K.N.); (Q.L.)
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- HUST-Suzhou Institute for Brainsmatics, JITRI Institute for Brainsmatics, Suzhou 215123, China
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Charlton JR, Li T, Wu T, deRonde K, Xu Y, Baldelomar EJ, Bennett KM. Use of novel structural features to identify urinary biomarkers during acute kidney injury that predict progression to chronic kidney disease. BMC Nephrol 2023; 24:178. [PMID: 37331957 DOI: 10.1186/s12882-023-03196-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 05/09/2023] [Indexed: 06/20/2023] Open
Abstract
BACKGROUND A significant barrier to biomarker development in the field of acute kidney injury (AKI) is the use of kidney function to identify candidates. Progress in imaging technology makes it possible to detect early structural changes prior to a decline in kidney function. Early identification of those who will advance to chronic kidney disease (CKD) would allow for the initiation of interventions to halt progression. The goal of this study was to use a structural phenotype defined by magnetic resonance imaging and histology to advance biomarker discovery during the transition from AKI to CKD. METHODS Urine was collected and analyzed from adult C57Bl/6 male mice at four days and 12 weeks after folic acid-induced AKI. Mice were euthanized 12 weeks after AKI and structural metrics were obtained from cationic ferritin-enhanced-MRI (CFE-MRI) and histologic assessment. The fraction of proximal tubules, number of atubular glomeruli (ATG), and area of scarring were measured histologically. The correlation between the urinary biomarkers at the AKI or CKD and CFE-MRI derived features was determined, alone or in combination with the histologic features, using principal components. RESULTS Using principal components derived from structural features, twelve urinary proteins were identified at the time of AKI that predicted structural changes 12 weeks after injury. The raw and normalized urinary concentrations of IGFBP-3 and TNFRII strongly correlated to the structural findings from histology and CFE-MRI. Urinary fractalkine concentration at the time of CKD correlated with structural findings of CKD. CONCLUSIONS We have used structural features to identify several candidate urinary proteins that predict whole kidney pathologic features during the transition from AKI to CKD, including IGFBP-3, TNFRII, and fractalkine. In future work, these biomarkers must be corroborated in patient cohorts to determine their suitability to predict CKD after AKI.
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Affiliation(s)
- Jennifer R Charlton
- School of Medicine, Department of Pediatrics, Division Nephrology, University of Virginia, Box 800386, Charlottesville, VA, 22903, USA.
| | - Teng Li
- Department of Computer Science, School of Computing and Augmented Intelligence, Arizona State University, Tempe, AZ, USA
| | - Teresa Wu
- Department of Industrial Engineering, School of Computing and Augmented Intelligence, Arizona State University, Tempe, AZ, USA
| | - Kimberly deRonde
- School of Medicine, Department of Pediatrics, Division Nephrology, University of Virginia, Box 800386, Charlottesville, VA, 22903, USA
| | - Yanzhe Xu
- Department of Industrial Engineering, School of Computing and Augmented Intelligence, Arizona State University, Tempe, AZ, USA
| | - Edwin J Baldelomar
- Washington University in St. Louis, Mallinckrodt Institute of Radiology, St. Louis MO, USA
| | - Kevin M Bennett
- Washington University in St. Louis, Mallinckrodt Institute of Radiology, St. Louis MO, USA
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7
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Zhu J, Liu X, Xu J, Deng Y, Wang P, Liu Z, Yang Q, Li D, Yu T, Zhu D. A versatile vessel casting method for fine mapping of vascular networks using a hydrogel-based lipophilic dye solution. CELL REPORTS METHODS 2023; 3:100407. [PMID: 36936073 PMCID: PMC10014313 DOI: 10.1016/j.crmeth.2023.100407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 12/11/2022] [Accepted: 01/18/2023] [Indexed: 02/10/2023]
Abstract
Efficient labeling of the vasculature is important for understanding the organization of vascular networks. Here, we propose VALID, a vessel-labeling method that enables visualization of vascular networks with tissue clearing and light-sheet microscopy. VALID transforms traditional lipophilic dye solution into hydrogel by introducing gelatin and restrains the dye aggregation, resulting in complete and uniform vessel-labeling patterns with high signal-to-background ratios. VALID also enhances the compatibility of lipophilic dyes with solvent-based tissue-clearing protocols, which was hard to achieve previously. Using VALID, we combined lipophilic dyes with solvent-based tissue-clearing techniques to perform 3D reconstructions of vasculature within mouse brain and spinal cord. We also employed VALID for 3D visualization and quantification of microvascular damage in a middle cerebral artery occlusion mouse model. VALID should provide a simple, cost-effective vessel-labeling protocol that would significantly widen the applications of lipophilic dyes in research on cerebrovascular complications.
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Affiliation(s)
- Jingtan Zhu
- Britton Chance Center for Biomedical Photonics - MoE Key Laboratory for Biomedical Photonics, Advanced Biomedical Imaging Facility, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
| | - Xiaomei Liu
- Britton Chance Center for Biomedical Photonics - MoE Key Laboratory for Biomedical Photonics, Advanced Biomedical Imaging Facility, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
| | - Jianyi Xu
- Britton Chance Center for Biomedical Photonics - MoE Key Laboratory for Biomedical Photonics, Advanced Biomedical Imaging Facility, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
| | - Yating Deng
- Britton Chance Center for Biomedical Photonics - MoE Key Laboratory for Biomedical Photonics, Advanced Biomedical Imaging Facility, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
| | - Pingfu Wang
- Britton Chance Center for Biomedical Photonics - MoE Key Laboratory for Biomedical Photonics, Advanced Biomedical Imaging Facility, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
| | - Zhang Liu
- Britton Chance Center for Biomedical Photonics - MoE Key Laboratory for Biomedical Photonics, Advanced Biomedical Imaging Facility, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
| | - Qihang Yang
- Britton Chance Center for Biomedical Photonics - MoE Key Laboratory for Biomedical Photonics, Advanced Biomedical Imaging Facility, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
| | - Dongyu Li
- Britton Chance Center for Biomedical Photonics - MoE Key Laboratory for Biomedical Photonics, Advanced Biomedical Imaging Facility, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
| | - Tingting Yu
- Britton Chance Center for Biomedical Photonics - MoE Key Laboratory for Biomedical Photonics, Advanced Biomedical Imaging Facility, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
| | - Dan Zhu
- Britton Chance Center for Biomedical Photonics - MoE Key Laboratory for Biomedical Photonics, Advanced Biomedical Imaging Facility, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
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8
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Baldelomar EJ, Emoto KC, Jordan MVC, Charlton JR, Reichert DE, Parvin N, Yokono C, Hann BD, Bennett KM. Synthesis and Expression of a Targeted, Ferritin-Based Tracer for PET Imaging of Kidney Glomeruli. Methods Mol Biol 2023; 2664:201-213. [PMID: 37423992 DOI: 10.1007/978-1-0716-3179-9_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Cationic ferritin (CF) has been developed as a multimodal, targeted imaging tracer to directly detect and map nephrons in the kidney in vivo. Direct detection of functional nephrons provides a unique, sensitive biomarker to predict or monitor kidney disease progression. CF has been developed to map functional nephron number from magnetic resonance imaging (MRI) or positron emission tomography (PET). Previous preclinical imaging studies have used non-human-derived ferritin and commercial formulations that must still be developed for translation to clinical use. Here we describe the reproducible formulation of CF (either derived from horse or from human recombinant ferritin) optimized for intravenous injection and radiolabeling by PET. The human recombinant heteropolymer ferritin is spontaneously assembled in liquid culture (Escherichia coli, E. coli) and modified to form human recombinant cationic ferritin (HrCF) to mitigate potential immunologic reactions for use in humans.
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Affiliation(s)
- Edwin J Baldelomar
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Kasey C Emoto
- Department of Biology, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Maria Veronica Clavijo Jordan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, USA
| | - Jennifer R Charlton
- Department of Pediatrics, Division of Nephrology, University of Virginia, Charlottesville, VA, USA
| | - David E Reichert
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Neda Parvin
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Courtnie Yokono
- Department of Biology, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Bradley D Hann
- Department of Biology, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Kevin M Bennett
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA.
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9
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Baldelomar EJ, Charlton JR, Bennett KM. Mapping single-nephron filtration in the isolated, perfused rat kidney using magnetic resonance imaging. Am J Physiol Renal Physiol 2022; 323:F602-F611. [PMID: 36049066 PMCID: PMC9602809 DOI: 10.1152/ajprenal.00103.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 08/16/2022] [Accepted: 08/25/2022] [Indexed: 12/14/2022] Open
Abstract
The kidney has an extraordinary ability to maintain glomerular filtration despite natural fluctuations in blood pressure and nephron loss. This is partly due to local coordination between single-nephron filtration and vascular perfusion. An improved understanding of the three-dimensional (3-D) functional coordination between nephrons and the vasculature may provide a new perspective of the heterogeneity of kidney function and could inform targeted therapies and timed interventions to slow or prevent the progression of kidney disease. Here, we developed magnetic resonance imaging (MRI) tools to visualize single-nephron function in 3-D throughout the isolated perfused rat kidney. We used an intravenous slow perfusion of a glomerulus-targeted imaging tracer [cationized ferritin (CF)] to map macromolecular dynamics and to identify glomeruli in 3-D, followed by a bolus of a freely filtered tracer (gadolinium diethylenetriamine penta-acetic acid) to map filtration kinetics. There was a wide intrakidney distribution of CF binding rates and estimated single-nephron glomerular filtration rate (eSNGFR) between nephrons. eSNGFR and CF uptake rates did not vary significantly by distance from the kidney surface. eSNGFR varied from ∼10 to ∼100 nL/min throughout the kidney. Whole single-kidney GFR was similar across all kidneys, despite differences in the distributions eSNGFR of and glomerular number, indicating a robust adaptive regulation of individual nephrons to maintain constant single-kidney GFR in the presence of a natural variation in nephron number. This work provides a framework for future studies of single-nephron function in the whole isolated perfused kidney and experiments of single-nephron function in vivo using MRI.NEW & NOTEWORTHY We report MRI tools to measure and map single-nephron function in the isolated, perfused rat kidney. We used imaging tracers to identify nephrons throughout the kidney and to measure the delivery and filtration of the tracers at the location of the glomeruli. With this technique, we directly measured physiological parameters including estimated single-nephron glomerular filtration rate throughout the kidney. This work provides a foundation for new studies to simultaneously map the function of large numbers of nephrons.
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Affiliation(s)
- Edwin J Baldelomar
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Jennifer R Charlton
- Division of Nephrology, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Kevin M Bennett
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
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10
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GAN Training Acceleration Using Fréchet Descriptor-Based Coreset. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12157599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Generative Adversarial Networks (GANs) are a class of deep learning models being applied to image processing. GANs have demonstrated state-of-the-art performance in applications such as image generation and image-to-image translation, just to name a few. However, with this success comes the realization that the training of GANs takes a long time and is often limited by available computing resources. In this research, we propose to construct a Coreset using Fréchet Descriptor Distances (FDD-Coreset) to accelerate the training of GAN for blob identification. We first propose a Fréchet Descriptor Distance (FDD) to measure the difference between each pair of blob images based on the statistics derived from blob distribution. The Coreset is then employed using our proposed FDD metric to select samples from the entire dataset for GAN training. A 3D-simulated dataset of blobs and a 3D MRI dataset of human kidneys are studied. Using computation time and eight performance metrics, the GAN trained on the FDD-Coreset is compared against the model trained on the entire dataset and an Inception and Euclidean Distance-based Coreset (IED-Coreset). We conclude that the FDD-Coreset not only significantly reduces the training time, but also achieves higher denoising performance and maintains approximate performance of blob identification compared with training on the entire dataset.
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11
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Deng L, Chen J, Li Y, Han Y, Fan G, Yang J, Cao D, Lu B, Ning K, Nie S, Zhang Z, Shen D, Zhang Y, Fu W, Wang WE, Wan Y, Li S, Feng YQ, Luo Q, Yuan J. Cryo-Fluorescence Micro-Optical Sectioning Tomography for Volumetric Imaging of Various Whole Organs with Subcellular Resolution. iScience 2022; 25:104805. [PMID: 35992061 PMCID: PMC9389242 DOI: 10.1016/j.isci.2022.104805] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 06/17/2022] [Accepted: 07/15/2022] [Indexed: 11/20/2022] Open
Abstract
Optical visualization of complex microstructures in the entire organ is essential for biomedical research. However, the existing methods fail to accurately acquire the detailed microstructures of whole organs with good morphological and biochemical preservation. This study proposes a cryo-fluorescence micro-optical sectioning tomography (cryo-fMOST) to image whole organs in three dimensions (3D) with submicron resolution. The system comprises a line-illumination microscope module, cryo-microtome, three-stage refrigeration module, and heat insulation device. To demonstrate the imaging capacity and wide applicability of the system, we imaged and reconstructed various organs of mice in 3D, including the healthy tongue, kidney, and brain, as well as the infarcted heart. More importantly, imaged brain slices were performed sugar phosphates determination and fluorescence in situ hybridization imaging to verify the compatibility of multi-omics measurements. The results demonstrated that cryo-fMOST is capable of acquiring high-resolution morphological details of various whole organs and may be potentially useful for spatial multi-omics. Cryo-fluorescence micro-optical sectioning tomography (Cryo-fMOST) was achieved 3D imaging of whole mouse tongue, kidney, heart, and brain at submicron resolution Frozen state well preserves tissues’ original morphology and biochemical information Cryo-fMOST is compatible with sugar phosphates determination and FISH measurement
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Affiliation(s)
- Lei Deng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jianwei Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yafeng Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yutong Han
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Guoqing Fan
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jie Yang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Dongjian Cao
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Bolin Lu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Kefu Ning
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Shuo Nie
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zoutao Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Dan Shen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yunfei Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wenbin Fu
- Department of Cardiology, Daping Hospital, Army Medical University, Chongqing 400038, China
| | - Wei Eric Wang
- Department of Cardiology, Daping Hospital, Army Medical University, Chongqing 400038, China
| | - Ying Wan
- Biomedical Analysis Center, Army Medical University, Chongqing 400038, China
- Chongqing Key Laboratory of Cytomics, Chongqing 400038, China
| | - Sha Li
- Department of Chemistry, Wuhan University, Wuhan 430072, China
- School of Public Health, Wuhan University, Wuhan 430071, China
| | - Yu-Qi Feng
- Department of Chemistry, Wuhan University, Wuhan 430072, China
- School of Public Health, Wuhan University, Wuhan 430071, China
| | - Qingming Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- School of Biomedical Engineering, Hainan University, Haikou, 570228, China
- Corresponding author
| | - Jing Yuan
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Innovation Institute, Huazhong University of Science and Technology, Wuhan 430074, China
- HUST-Suzhou Institute for Brainsmatics, JITRI Institute for Brainsmatics, Suzhou, 215123, China
- Corresponding author
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12
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Pan X. Cholesterol Metabolism in Chronic Kidney Disease: Physiology, Pathologic Mechanisms, and Treatment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1372:119-143. [PMID: 35503178 PMCID: PMC11106795 DOI: 10.1007/978-981-19-0394-6_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
High plasma levels of lipids and/or lipoproteins are risk factors for atherosclerosis, nonalcoholic fatty liver disease (NAFLD), obesity, and diabetes. These four conditions have also been identified as risk factors leading to the development of chronic kidney disease (CKD). Although many pathways that generate high plasma levels of these factors have been identified, most clinical and physiologic dysfunction results from aberrant assembly and secretion of lipoproteins. The results of several published studies suggest that elevated levels of low-density lipoprotein (LDL)-cholesterol are a risk factor for atherosclerosis, myocardial infarction, coronary artery calcification associated with type 2 diabetes, and NAFLD. Cholesterol metabolism has also been identified as an important pathway contributing to the development of CKD; clinical treatments designed to alter various steps of the cholesterol synthesis and metabolism pathway are currently under study. Cholesterol synthesis and catabolism contribute to a multistep process with pathways that are regulated at the cellular level in renal tissue. Cholesterol metabolism may also be regulated by the balance between the influx and efflux of cholesterol molecules that are capable of crossing the membrane of renal proximal tubular epithelial cells and podocytes. Cellular accumulation of cholesterol can result in lipotoxicity and ultimately kidney dysfunction and failure. Thus, further research focused on cholesterol metabolism pathways will be necessary to improve our understanding of the impact of cholesterol restriction, which is currently a primary intervention recommended for patients with dyslipidemia.
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Affiliation(s)
- Xiaoyue Pan
- Department of Foundations of Medicine, New York University Long Island School of Medicine, Mineola, NY, USA.
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13
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Zhu J, Liu X, Deng Y, Li D, Yu T, Zhu D. Tissue optical clearing for 3D visualization of vascular networks: A review. Vascul Pharmacol 2021; 141:106905. [PMID: 34506969 DOI: 10.1016/j.vph.2021.106905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 12/01/2022]
Abstract
Reconstruction of the vasculature of intact tissues/organs down to the capillary level is essential for understanding the development and remodeling of vascular networks under physiological and pathological conditions. Optical imaging techniques can provide sufficient resolution to distinguish small vessels with several microns, but the imaging depth is somewhat limited due to the high light scattering of opaque tissue. Recently, various tissue optical clearing methods have been developed to overcome light attenuation and improve the imaging depth both for ex-vivo and in-vivo visualizations. Tissue clearing combined with vessel labeling techniques and advanced optical tomography enables successful mapping of the vasculature of different tissues/organs, as well as dynamically monitoring vessel function under normal and pathological conditions. Here, we briefly introduce the commonly-used labeling strategies for entire vascular networks, the current tissue optical clearing techniques available for various tissues, as well as the advanced optical imaging techniques for fast, high-resolution structural and functional imaging for blood vessels. We also discuss the applications of these techniques in the 3D visualization of vascular networks in normal tissues, and the vascular remodeling in several typical pathological models in clinical research. This review is expected to provide valuable insights for researchers to study the potential mechanisms of various vessel-associated diseases using tissue optical clearing pipeline.
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Affiliation(s)
- Jingtan Zhu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Xiaomei Liu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Yating Deng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Dongyu Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Tingting Yu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
| | - Dan Zhu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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14
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Xu Y, Wu T, Charlton JR, Gao F, Bennett KM. Small Blob Detector Using Bi-Threshold Constrained Adaptive Scales. IEEE Trans Biomed Eng 2021; 68:2654-2665. [PMID: 33347401 PMCID: PMC8461780 DOI: 10.1109/tbme.2020.3046252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Recent advances in medical imaging technology bring great promises for medicine practices. Imaging biomarkers are discovered to inform disease diagnosis, prognosis, and treatment assessment. Detecting and segmenting objects from images are often the first steps in quantitative measurement of these biomarkers. The challenges of detecting objects in images, particularly small objects known as blobs, include low image resolution, image noise and overlap among the blobs. This research proposes a Bi-Threshold Constrained Adaptive Scale (BTCAS) blob detector to uncover the relationship between the U-Net threshold and the Difference of Gaussian (DoG) scale to derive a multi-threshold, multi-scale small blob detector. With lower and upper bounds on the probability thresholds from U-Net, two binarized maps of the distance are rendered between blob centers. Each blob is transformed to a DoG space with an adaptively identified local optimum scale. A Hessian convexity map is rendered using the adaptive scale, and the under-segmentation typical of the U-Net is resolved. To validate the performance of the proposed BTCAS, a 3D simulated dataset (n = 20) of blobs, a 3D MRI dataset of human kidneys and a 3D MRI dataset of mouse kidneys, are studied. BTCAS is compared against four state-of-the-art methods: HDoG, U-Net with standard thresholding, U-Net with optimal thresholding, and UH-DoG using precision, recall, F-score, Dice and IoU. We conclude that BTCAS statistically outperforms the compared detectors.
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Affiliation(s)
- Yanzhe Xu
- School of Computing, Informatics and Decision Systems Engineering, and ASU-Mayo Center for Innovative Imaging, Arizona State University, Tempe, AZ, 85281, USA
| | - Teresa Wu
- School of Computing, Informatics and Decision Systems Engineering, and ASU-Mayo Center for Innovative Imaging, Arizona State University, Tempe, AZ, 85281, USA
| | - Jennifer R. Charlton
- Department of Pediatrics, Division Nephrology, University of Virginia, Charlottesville, 22908-0386, USA
| | - Fei Gao
- School of Computing, Informatics and Decision Systems Engineering, and ASU-Mayo Center for Innovative Imaging, Arizona State University, Tempe, AZ, 85281, USA
| | - Kevin M. Bennett
- Department of Radiology, Washington University, St. Louis, MO, 63130, USA
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15
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Korin B, Chung JJ, Avraham S, Shaw AS. Preparation of single-cell suspensions of mouse glomeruli for high-throughput analysis. Nat Protoc 2021; 16:4068-4083. [PMID: 34282333 DOI: 10.1038/s41596-021-00578-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 05/27/2021] [Indexed: 02/06/2023]
Abstract
The kidney glomerulus is essential for proper kidney function. Until recently, technical challenges associated with glomerular isolation and subsequent dissolution into single cells have limited the detailed characterization of cells in the glomerulus. Previous techniques of kidney dissociation result in low glomerular cell yield, which limits high-throughput analysis. The ability to efficiently purify glomeruli and digest the tissue into single cells is especially important for single-cell characterization methods. Here, we present a detailed and comprehensive technique for the extraction and preparation of mouse glomerular cells, with high yield and viability. The method includes direct renal perfusion of Dynabeads via the renal artery followed by kidney dissociation and isolation of glomeruli by magnet; these steps provide a high number and purity of isolated glomeruli, which are further dissociated into single cells. The balanced representation of podocytes, mesangial and endothelial cells in single-cell suspensions of mouse glomeruli, and the high cell viability observed, confirm the efficiency of our method. With some practice, the procedure can be done in <3 h (excluding equipment setup and data analysis). This protocol provides a valuable technique for advancing future single-cell-based studies of the glomerulus in health, injury and disease.
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Affiliation(s)
- Ben Korin
- Department of Research Biology, Genentech, South San Francisco, CA, USA
| | - Jun-Jae Chung
- Department of Research Biology, Genentech, South San Francisco, CA, USA
| | - Shimrit Avraham
- Department of Research Biology, Genentech, South San Francisco, CA, USA
| | - Andrey S Shaw
- Department of Research Biology, Genentech, South San Francisco, CA, USA.
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16
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Charlton JR, Xu Y, Parvin N, Wu T, Gao F, Baldelomar EJ, Morozov D, Beeman SC, Derakhshan J, Bennett KM. Image analysis techniques to map pyramids, pyramid structure, glomerular distribution, and pathology in the intact human kidney from 3-D MRI. Am J Physiol Renal Physiol 2021; 321:F293-F304. [PMID: 34282957 DOI: 10.1152/ajprenal.00130.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Kidney pathologies are often highly heterogeneous. To comprehensively understand kidney structure and pathology, it is critical to develop tools to map tissue microstructure in the context of the whole, intact organ. Magnetic resonance imaging (MRI) can provide a unique, three-dimensional view of the kidney and allows for measurements of multiple pathological features. Here, we developed a platform to systematically render and map gross and microstructural features of the human kidney based on three-dimensional MRI. These features include pyramid number and morphology as well as the associated medulla and cortex. In a subset of these kidneys, we also mapped individual glomeruli and glomerular volumes using cationic ferritin-enhanced MRI to report intrarenal heterogeneity in glomerular density and size. Finally, we rendered and measured regions of nephron loss due to pathology and individual glomerular volumes in each pyramidal unit. This work provides new tools to comprehensively evaluate the kidney across scales, with potential applications in anatomic and physiological research, transplant allograft evaluation, biomarker development, biopsy guidance, and therapeutic monitoring. These image rendering and analysis tools could eventually impact the field of transplantation medicine to improve longevity matching of donor allografts and recipients and reduce discard rates through the direct assessment of donor kidneys.NEW & NOTEWORTHY We report the application of cutting-edge image analysis approaches to characterize the pyramidal geometry, glomerular microstructure, and heterogeneity of the whole human kidney imaged using MRI. This work establishes a framework to improve the detection of microstructural pathology to potentially facilitate disease monitoring or transplant evaluation in the individual kidney.
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Affiliation(s)
- Jennifer R Charlton
- Department of Pediatrics, University of Virginia Children's Hospital, Charlottesville, Virginia
| | - Yanzhe Xu
- School of Computing, Informatics, Decision Systems Engineering, Arizona State University, Tempe, Arizona.,Mayo Center for Innovative Imaging, Arizona State University, Tempe, Arizona
| | - Neda Parvin
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Teresa Wu
- School of Computing, Informatics, Decision Systems Engineering, Arizona State University, Tempe, Arizona.,Mayo Center for Innovative Imaging, Arizona State University, Tempe, Arizona
| | - Fei Gao
- School of Computing, Informatics, Decision Systems Engineering, Arizona State University, Tempe, Arizona.,Mayo Center for Innovative Imaging, Arizona State University, Tempe, Arizona
| | - Edwin J Baldelomar
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Darya Morozov
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Scott C Beeman
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona
| | - Jamal Derakhshan
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Kevin M Bennett
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
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17
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Assessment of nephron number and single-nephron glomerular filtration rate in a clinical setting. Hypertens Res 2021; 44:605-617. [PMID: 33526913 DOI: 10.1038/s41440-020-00612-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 01/31/2023]
Abstract
Total nephron counts vary widely between individuals and may affect susceptibility to certain diseases, including hypertension and chronic kidney disease. Detailed analyses of whole kidneys collected from autopsy patients remain the only method for accurately counting nephrons in humans, with no equivalent option in living subjects. Current technological advances have enabled estimations of nephron numbers in vivo, particularly the use of total nephron number and whole-kidney glomerular filtration rate to estimate the mean single-nephron glomerular filtration rate. The use of this method would allow physicians to detect dynamic changes in filtration function at the single-nephron level rather than to simply count the number of nephrons that appear to be functioning. Currently available methods for estimating total nephron number in clinical practice have the potential to overcome limitations associated with autopsy analyses and may therefore pave the way for new therapeutic interventions and improved clinical outcomes.
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18
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Charlton JR, Baldelomar EJ, Hyatt DM, Bennett KM. Nephron number and its determinants: a 2020 update. Pediatr Nephrol 2021; 36:797-807. [PMID: 32350665 PMCID: PMC7606355 DOI: 10.1007/s00467-020-04534-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/29/2020] [Accepted: 03/05/2020] [Indexed: 12/30/2022]
Abstract
Studies of human nephron number have been conducted for well over a century and have uncovered a large variability in nephron number. However, the mechanisms influencing nephron endowment and loss, along with the etiology for the wide range among individuals are largely unknown. Advances in imaging technology have allowed investigators to revisit the principles of renal structure and physiology and their roles in the progression of kidney disease. Here, we will review the latest data on the influences impacting nephron number, innovations made over the last 6 years to understand and integrate renal structure and function, and new developments in the tools used to count nephrons in vivo.
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Affiliation(s)
- Jennifer R. Charlton
- University of Virginia School of Medicine, Department of Pediatrics, Division of Nephrology, Charlottesville, VA, USA
| | - Edwin J. Baldelomar
- Washington University in St. Louis, Department of Radiology, St. Louis, MO, USA
| | - Dylan M. Hyatt
- University of Virginia, School of Medicine, Charlottesville, VA, USA
| | - Kevin M. Bennett
- Washington University in St. Louis, Department of Radiology, St. Louis, MO, USA
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19
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Bennett KM, Baldelomar EJ, Morozov D, Chevalier RL, Charlton JR. New imaging tools to measure nephron number in vivo: opportunities for developmental nephrology. J Dev Orig Health Dis 2021; 12:179-183. [PMID: 31983353 PMCID: PMC8765346 DOI: 10.1017/s204017442000001x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The mammalian kidney is a complex organ, requiring the concerted function of up to millions of nephrons. The number of nephrons is constant after nephrogenesis during development, and nephron loss over a life span can lead to susceptibility to acute or chronic kidney disease. New technologies are under development to count individual nephrons in the kidney in vivo. This review outlines these technologies and highlights their relevance to studies of human renal development and disease.
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Affiliation(s)
- K M Bennett
- Department of Radiology, Washington University, Saint Louis, MO, USA
| | - E J Baldelomar
- Department of Radiology, Washington University, Saint Louis, MO, USA
| | - D Morozov
- Department of Radiology, Washington University, Saint Louis, MO, USA
| | - R L Chevalier
- Department of Pediatrics, University of Virginia, Charlottesville, VA, USA
| | - J R Charlton
- Department of Pediatrics, University of Virginia, Charlottesville, VA, USA
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20
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Walsh C, Tafforeau P, Wagner WL, Jafree DJ, Bellier A, Werlein C, Kühnel MP, Boller E, Walker-Samuel S, Robertus JL, Long DA, Jacob J, Marussi S, Brown E, Holroyd N, Jonigk DD, Ackermann M, Lee PD. Multiscale three-dimensional imaging of intact human organs down to the cellular scale using hierarchical phase-contrast tomography. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.02.03.429481. [PMID: 33564772 PMCID: PMC7872374 DOI: 10.1101/2021.02.03.429481] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Human organs are complex, three-dimensional and multiscale systems. Spatially mapping the human body down through its hierarchy, from entire organs to their individual functional units and specialised cells, is a major obstacle to fully understanding health and disease. To meet this challenge, we developed hierarchical phase-contrast tomography (HiP-CT), an X-ray phase propagation technique utilising the European Synchrotron Radiation Facility's Extremely Brilliant Source: the world's first high-energy 4 th generation X-ray source. HiP-CT enabled three-dimensional and non-destructive imaging at near-micron resolution in soft tissues at one hundred thousand times the voxel size whilst maintaining the organ's structure. We applied HiP-CT to image five intact human parenchymal organs: brain, lung, heart, kidney and spleen. These were hierarchically assessed with HiP-CT, providing a structural overview of the whole organ alongside detail of the organ's individual functional units and cells. The potential applications of HiP-CT were demonstrated through quantification and morphometry of glomeruli in an intact human kidney, and identification of regional changes to the architecture of the air-tissue interface and alveolar morphology in the lung of a deceased COVID-19 patient. Overall, we show that HiP-CT is a powerful tool which can provide a comprehensive picture of structural information for whole intact human organs, encompassing precise details on functional units and their constituent cells to better understand human health and disease.
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Affiliation(s)
- C Walsh
- Centre for Advanced Biomedical Imaging, University College London, U.K
| | - P Tafforeau
- European Synchrotron Radiation Facility, Grenoble, France
| | - Willi L Wagner
- Dept of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany Translational Lung Research Centre Heidelberg (TLRC), German Lung Research Centre (DZL), Heidelberg, Germany
| | - D J Jafree
- Developmental Biology and Cancer Programme, Great Ormond Street Institute of Child Health, University College London, UK
- UCL MB/PhD Programme, Faculty of Medical Sciences, University College London, UK
| | - A Bellier
- French Alps Laboratory of Anatomy (LADAF), Grenoble Alpes University, Grenoble, France
| | - C Werlein
- Institute of Pathology, Hannover Medical School, Hannover, Germany (Carl-Neuberg-Straße 1, 30625 Hannover)
| | - M P Kühnel
- Institute of Pathology, Hannover Medical School, Hannover, Germany (Carl-Neuberg-Straße 1, 30625 Hannover)
- Member of the German Center for Lung Research (DZL), Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH)
| | - E Boller
- European Synchrotron Radiation Facility, Grenoble, France
| | - S Walker-Samuel
- Centre for Advanced Biomedical Imaging, University College London, U.K
| | - J L Robertus
- Department of Histopathology, Royal Brompton and Harefield NHS Foundation Trust, London, UK
- National Heart & Lung Institute, Imperial College London, London, UK
| | - D A Long
- Developmental Biology and Cancer Programme, Great Ormond Street Institute of Child Health, University College London, UK
| | - J Jacob
- Centre for Medical Image Computing, University College London, London, UK
- Department of Radiology, University College London Hospitals NHS Foundation Trust, London, UK
| | - S Marussi
- Department of Mechanical Engineering University College London, U.K
| | - E Brown
- Centre for Advanced Biomedical Imaging, University College London, U.K
| | - N Holroyd
- Centre for Advanced Biomedical Imaging, University College London, U.K
| | - D D Jonigk
- Institute of Pathology, Hannover Medical School, Hannover, Germany (Carl-Neuberg-Straße 1, 30625 Hannover)
- Member of the German Center for Lung Research (DZL), Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH)
| | - M Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz
| | - P D Lee
- Department of Mechanical Engineering University College London, U.K
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21
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Baldelomar EJ, Reichert DE, Shoghi KI, Beeman SC, Charlton JR, Strong L, Fettig N, Klaas A, Bennett KM. Mapping nephron mass in vivo using positron emission tomography. Am J Physiol Renal Physiol 2021; 320:F183-F192. [PMID: 33283644 PMCID: PMC8091936 DOI: 10.1152/ajprenal.00418.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 01/19/2023] Open
Abstract
Nephron number varies widely in humans. A low nephron endowment at birth or a loss of functioning nephrons is strongly linked to increased susceptibility to chronic kidney disease. In this work, we developed a contrast agent, radiolabeled cationic ferritin (RadioCF), to map functioning glomeruli in vivo in the kidney using positron emission tomography (PET). PET radiotracers can be detected in trace doses (<30 nmol), making them useful for rapid clinical translation. RadioCF is formed from cationic ferritin (CF) and with a radioisotope, Cu-64, incorporated into the ferritin core. We showed that RadioCF binds specifically to kidney glomeruli after intravenous injection in mice, whereas radiolabeled noncationic ferritin (RadioNF) and free Cu-64 do not. We then showed that RadioCF-PET can distinguish kidneys in healthy wild-type (WT) mice from kidneys in mice with oligosyndactylism (Os/+), a model of congenital hypoplasia and low nephron mass. The average standardized uptake value (SUV) measured by PET 90 min after injection was 21% higher in WT mice than in Os/+ mice, consistent with the higher glomerular density in WT mice. The difference in peak SUV from SUV at 90 min correlated with glomerular density in male mice from both WT and Os/+ cohorts (R2 = 0.98). Finally, we used RadioCF-PET to map functioning glomeruli in a donated human kidney. SUV within the kidney correlated with glomerular number (R2= 0.78) measured by CF-enhanced magnetic resonance imaging in the same locations. This work suggests that RadioCF-PET appears to accurately detect nephron mass and has the potential for clinical translation.
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Affiliation(s)
- Edwin J Baldelomar
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - David E Reichert
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Kooresh I Shoghi
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Scott C Beeman
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona
| | | | - Lori Strong
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Nikki Fettig
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Amanda Klaas
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Kevin M Bennett
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
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22
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Charlton JR, Tan W, Daouk G, Teot L, Rosen S, Bennett KM, Cwiek A, Nam S, Emma F, Jouret F, Oliveira JP, Tranebjærg L, Frykholm C, Mane S, Hildebrandt F, Srivastava T, Storm T, Christensen EI, Nielsen R. Beyond the tubule: pathological variants of LRP2, encoding the megalin receptor, result in glomerular loss and early progressive chronic kidney disease. Am J Physiol Renal Physiol 2020; 319:F988-F999. [PMID: 33103447 DOI: 10.1152/ajprenal.00295.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Pathogenic variants in the LRP2 gene, encoding the multiligand receptor megalin, cause a rare autosomal recessive syndrome: Donnai-Barrow/Facio-Oculo-Acoustico-Renal (DB/FOAR) syndrome. Because of the rarity of the syndrome, the long-term consequences of the tubulopathy on human renal health have been difficult to ascertain, and the human clinical condition has hitherto been characterized as a benign tubular condition with asymptomatic low-molecular-weight proteinuria. We investigated renal function and morphology in a murine model of DB/FOAR syndrome and in patients with DB/FOAR. We analyzed glomerular filtration rate in mice by FITC-inulin clearance and clinically characterized six families, including nine patients with DB/FOAR and nine family members. Urine samples from patients were analyzed by Western blot analysis and biopsy materials were analyzed by histology. In the mouse model, we used histological methods to assess nephrogenesis and postnatal renal structure and contrast-enhanced magnetic resonance imaging to assess glomerular number. In megalin-deficient mice, we found a lower glomerular filtration rate and an increase in the abundance of injury markers, such as kidney injury molecule-1 and N-acetyl-β-d-glucosaminidase. Renal injury was validated in patients, who presented with increased urinary kidney injury molecule-1, classical markers of chronic kidney disease, and glomerular proteinuria early in life. Megalin-deficient mice had normal nephrogenesis, but they had 19% fewer nephrons in early adulthood and an increased fraction of nephrons with disconnected glomerulotubular junction. In conclusion, megalin dysfunction, as present in DB/FOAR syndrome, confers an increased risk of progression into chronic kidney disease.
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Affiliation(s)
- Jennifer R Charlton
- Division of Nephrology, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Weizhen Tan
- Division of Nephrology, Massachusetts General Hospital for Children, Boston, Massachusetts
| | - Ghaleb Daouk
- Division of Nephrology, Massachusetts General Hospital for Children, Boston, Massachusetts
| | - Lisa Teot
- Department of Pathology, Boston Children's Hospital, Boston, Massachusetts
| | - Seymour Rosen
- Department of Pathology, Boston Children's Hospital, Boston, Massachusetts.,Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Kevin M Bennett
- Department of Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Aleksandra Cwiek
- Division of Nephrology, Department of Pediatrics, University of Virginia, Charlottesville, Virginia
| | - Sejin Nam
- Department of Physics, University of Hawai'i at Manoa, Manoa, Hawai'i
| | - Francesco Emma
- Division of Nephrology, Department of Pediatric Subspecialties, Bambino Gesù Children's Hospital- Istituto di Ricovero e Cura a Carattere Scientifico, Rome, Italy
| | - François Jouret
- Groupe Interdisciplinaire de Génoprotéomique Appliquée, Unit of Cardiovascular Sciences, University of Liège, Liège, Belgium
| | - João Paulo Oliveira
- Service of Medical Genetics, São João University Hospital Centre and Faculty of Medicine, University of Porto and i3S-Institute for Health Research and Innovation, Porto, Portugal
| | - Lisbeth Tranebjærg
- Department of Clinical Genetics, Rigshospitalet/The Kennedy Centre, Copenhagen, Denmark.,Institute of Clinical Medicine, University of Copenhagen, The Panum Institute, Copenhagen, Denmark
| | - Carina Frykholm
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Shrikant Mane
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Friedhelm Hildebrandt
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Tina Storm
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Rikke Nielsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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23
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Parvin N, Charlton JR, Baldelomar EJ, Derakhshan JJ, Bennett KM. Mapping vascular and glomerular pathology in a rabbit model of neonatal acute kidney injury using MRI. Anat Rec (Hoboken) 2020; 303:2716-2728. [PMID: 32445514 PMCID: PMC7680718 DOI: 10.1002/ar.24419] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 01/30/2020] [Accepted: 03/03/2020] [Indexed: 12/27/2022]
Abstract
Acute kidney injury (AKI) in premature neonates is common due to the administration of life-saving therapies. The impact of AKI on renal morphology and susceptibility to further renal damage is poorly understood. Recent advances in radiological imaging have allowed integration of soft tissue morphology in the intact organ, facilitating a more complete understanding of changes in tissue microstructure associated with pathology. Here, we applied magnetic resonance imaging (MRI) to detect both glomerular and vascular changes in a rabbit model of neonatal AKI, induced by indomethacin and gentamicin. Using combined spin-echo MRI and cationic ferritin enhanced gradient-echo MRI (CFE-MRI), we observed (a) an increased cortical arterial diameter in the AKI cohort compared to healthy controls, and (b) focal loss of vascular density and glomerular loss in a circumferential band ~1 mm from the cortical surface. This combined use of vascular and glomerular imaging may give insight into the etiology of AKI and its impact on renal health later in life.
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Affiliation(s)
- Neda Parvin
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Jennifer R Charlton
- University of Virginia Children's Hospital, Department of Pediatrics, Charlottesville, Virginia, USA
| | - Edwin J Baldelomar
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Jamal J Derakhshan
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Kevin M Bennett
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA
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24
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Charlton JR, Xu Y, Wu T, deRonde KA, Hughes JL, Dutta S, Oxley GT, Cwiek A, Cathro HP, Charlton NP, Conaway MR, Baldelomar EJ, Parvin N, Bennett KM. Magnetic resonance imaging accurately tracks kidney pathology and heterogeneity in the transition from acute kidney injury to chronic kidney disease. Kidney Int 2020; 99:173-185. [PMID: 32916180 DOI: 10.1016/j.kint.2020.08.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 08/07/2020] [Accepted: 08/20/2020] [Indexed: 01/09/2023]
Abstract
Acute kidney injury (AKI) increases the risk for chronic kidney disease (CKD). However, there are few tools to detect microstructural changes after AKI. Here, cationic ferritin-enhanced magnetic resonance imaging (CFE-MRI) was applied to examine the heterogeneity of kidney pathology in the transition from AKI to CKD. Adult male mice received folic acid followed by cationic ferritin and were euthanized at four days (AKI), four weeks (CKD-4) or 12 weeks (CKD-12). Kidneys were examined by histologic methods and CFE-MRI. In the CKD-4 and CKD-12 groups, glomerular number was reduced and atubular cortical lesions were observed. Apparent glomerular volume was larger in the AKI, CKD-4 and CKD-12 groups compared to controls. Glomerular hypertrophy occurred with ageing. Interglomerular distance and glomerular density were combined with other MRI metrics to distinguish the AKI and CKD groups from controls. Despite significant heterogeneity, the noninvasive (MRI-based) metrics were as accurate as invasive (histological) metrics at distinguishing AKI and CKD from controls. To assess the toxicity of cationic ferritin in a CKD model, CKD-4 mice received cationic ferritin and were examined one week later. The CKD-4 groups with and without cationic ferritin were similar, except the iron content of the kidney, liver, and spleen was greater in the CKD-4 plus cationic ferritin group. Thus, our study demonstrates the accuracy and safety of CFE-MRI to detect whole kidney pathology allowing for the development of novel biomarkers of kidney disease and providing a foundation for future in vivo longitudinal studies in mouse models of AKI and CKD to track nephron fate.
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Affiliation(s)
- Jennifer R Charlton
- Department of Pediatrics, Division Nephrology, University of Virginia, Charlottesville, Virginia, USA.
| | - Yanzhe Xu
- ASU-Mayo Center for Innovative Imaging, School of Computing, Informatics, Decision Systems Engineering, Arizona State University, Tempe, Arizona, USA
| | - Teresa Wu
- ASU-Mayo Center for Innovative Imaging, School of Computing, Informatics, Decision Systems Engineering, Arizona State University, Tempe, Arizona, USA
| | - Kim A deRonde
- Department of Pediatrics, Division Nephrology, University of Virginia, Charlottesville, Virginia, USA
| | | | - Shourik Dutta
- School of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Gavin T Oxley
- University of Virginia, Charlottesville, Virginia, USA
| | | | - Helen P Cathro
- Department of Pathology University of Virginia, Charlottesville, Virginia, USA
| | - Nathan P Charlton
- Department of Toxicology, University of Virginia, Virginia, Charlottesville, USA
| | - Mark R Conaway
- Division of Translational Research and Applied Statistics Department of Public Health Sciences, University of Virginia, Charlottesville, Virginia, USA
| | - Edwin J Baldelomar
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Neda Parvin
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Kevin M Bennett
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA
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25
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Zhu J, Yu T, Li Y, Xu J, Qi Y, Yao Y, Ma Y, Wan P, Chen Z, Li X, Gong H, Luo Q, Zhu D. MACS: Rapid Aqueous Clearing System for 3D Mapping of Intact Organs. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1903185. [PMID: 32328422 PMCID: PMC7175264 DOI: 10.1002/advs.201903185] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/16/2020] [Indexed: 05/21/2023]
Abstract
Tissue optical clearing techniques have provided important tools for large-volume imaging. Aqueous-based clearing methods are known for good fluorescence preservation and scalable size maintenance, but are limited by long incubation time, insufficient clearing performance, or requirements for specialized devices. Additionally, few clearing methods are compatible with widely used lipophilic dyes while maintaining high clearing performance. Here, to address these issues, m-xylylenediamine (MXDA) is firstly introduced into tissue clearing and used to develop a rapid, highly efficient aqueous clearing method with robust lipophilic dyes compatibility, termed MXDA-based Aqueous Clearing System (MACS). MACS can render whole adult brains highly transparent within 2.5 days and is also applicable for other intact organs. Meanwhile, MACS possesses ideal compatibility with multiple probes, especially for lipophilic dyes. MACS achieves 3D imaging of the intact neural structures labeled by various techniques. Combining MACS with DiI labeling, MACS allows reconstruction of the detailed vascular structures of various organs and generates 3D pathology of glomeruli tufts in healthy and diabetic kidneys. Therefore, MACS provides a useful method for 3D mapping of intact tissues and is expected to facilitate morphological, physiological, and pathological studies of various organs.
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Affiliation(s)
- Jingtan Zhu
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Tingting Yu
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Yusha Li
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Jianyi Xu
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Yisong Qi
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Yingtao Yao
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Yilin Ma
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Peng Wan
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Zhilong Chen
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Xiangning Li
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Hui Gong
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Qingming Luo
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
| | - Dan Zhu
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China
- MoE Key Laboratory for Biomedical PhotonicsHuazhong University of Science and TechnologyWuhan430074China
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26
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Xu Y, Wu T, Gao F, Charlton JR, Bennett KM. Improved small blob detection in 3D images using jointly constrained deep learning and Hessian analysis. Sci Rep 2020; 10:326. [PMID: 31941994 PMCID: PMC6962386 DOI: 10.1038/s41598-019-57223-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Accepted: 12/20/2019] [Indexed: 12/23/2022] Open
Abstract
Imaging biomarkers are being rapidly developed for early diagnosis and staging of disease. The development of these biomarkers requires advances in both image acquisition and analysis. Detecting and segmenting objects from images are often the first steps in quantitative measurement of these biomarkers. The challenges of detecting objects in images, particularly small objects known as blobs, include low image resolution, image noise and overlap between the blobs. The Difference of Gaussian (DoG) detector has been used to overcome these challenges in blob detection. However, the DoG detector is susceptible to over-detection and must be refined for robust, reproducible detection in a wide range of medical images. In this research, we propose a joint constraint blob detector from U-Net, a deep learning model, and Hessian analysis, to overcome these problems and identify true blobs from noisy medical images. We evaluate this approach, UH-DoG, using a public 2D fluorescent dataset for cell nucleus detection and a 3D kidney magnetic resonance imaging dataset for glomerulus detection. We then compare this approach to methods in the literature. While comparable to the other four comparing methods on recall, the UH-DoG outperforms them on both precision and F-score.
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Affiliation(s)
- Yanzhe Xu
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, 699S Mill Ave, Tempe, AZ, 85281, USA
| | - Teresa Wu
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, 699S Mill Ave, Tempe, AZ, 85281, USA.
| | - Fei Gao
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, 699S Mill Ave, Tempe, AZ, 85281, USA
| | - Jennifer R Charlton
- Department of Pediatrics, Division Nephrology, University of Virginia, Charlottesville, VA, 22908, USA
| | - Kevin M Bennett
- Department of Radiology, Washington University, St. Louis, MO, 63130, USA
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27
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Baldelomar EJ, Charlton JR, deRonde KA, Bennett KM. In vivo measurements of kidney glomerular number and size in healthy and Os /+ mice using MRI. Am J Physiol Renal Physiol 2019; 317:F865-F873. [PMID: 31339774 DOI: 10.1152/ajprenal.00078.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The development of chronic kidney disease (CKD) is associated with the loss of functional nephrons. However, there are no methods to directly measure nephron number in living subjects. Thus, there are no methods to track the early stages of progressive CKD before changes in total renal function. In this work, we used cationic ferritin-enhanced magnetic resonance imaging (CFE-MRI) to enable measurements of glomerular number (Nglom) and apparent glomerular volume (aVglom) in vivo in healthy wild-type (WT) mice (n = 4) and mice with oligosyndactylism (Os/+; n = 4), a model of congenital renal hypoplasia leading to nephron reduction. We validated in vivo measurements of Nglom and aVglom by high-resolution ex vivo MRI. CFE-MRI measured a mean Nglom of 12,220 ± 2,028 and 6,848 ± 1,676 (means ± SD) for WT and Os/+ mouse kidneys in vivo, respectively. Nglom measured in all mice in vivo using CFE-MRI varied by an average 15% from Nglom measured ex vivo in the same kidney (α = 0.05, P = 0.67). To confirm that CFE-MRI can also be used to track nephron endowment longitudinally, a WT mouse was imaged three times by CFE-MRI over 2 wk. Values of Nglom measured in vivo in the same kidney varied within ~3%. Values of aVglom calculated from CFE-MRI in vivo were significantly different (~15% on average, P < 0.01) from those measured ex vivo, warranting further investigation. This is the first report of direct measurements of Nglom and aVglom in healthy and diseased mice in vivo.
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Affiliation(s)
- Edwin J Baldelomar
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri.,Department of Physics, University of Hawai'i at Mānoa, Honolulu, Hawaii
| | - Jennifer R Charlton
- University of Virginia Children's Hospital, Department of Pediatrics, Charlottesville, Virginia
| | - Kimberly A deRonde
- University of Virginia Children's Hospital, Department of Pediatrics, Charlottesville, Virginia
| | - Kevin M Bennett
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri.,Department of Biology, University of Hawai'i at Mānoa, Honolulu, Hawaii
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Zeng X, Ma S, Kruger JM, Wang R, Tan X, Qian C. High-resolution MRI of kidney microstructures at 7.05 T with an endo-colonic Wireless Amplified NMR detector. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 303:121-127. [PMID: 31051387 PMCID: PMC6590910 DOI: 10.1016/j.jmr.2019.04.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/19/2019] [Accepted: 04/21/2019] [Indexed: 05/06/2023]
Abstract
To map the hemodynamic responses of kidney microstructures at 7.05 T with improved sensitivity, a Wireless Amplified NMR Detector (WAND) with cylindrical symmetry was fabricated as an endoluminal detector that can convert externally provided wireless signal at 600.71 MHz into amplified MR signals at 300.33 MHz. When this detector was inserted inside colonic lumens to sensitively observe adjacent kidneys, it could clearly identify kidney microstructures in the renal cortex and renal medullary. Owing to the higher achievable spatial resolution, differential hemodynamic responses of kidney microstructures under different breathing conditions could be individually quantified to estimate the underlying correlation between oxygen bearing capability and local levels of oxygen unsaturation. The WAND's ability to map Blood Oxygen Level Dependent (BOLD) signal responses in heterogeneous microstructures will pave way for early-stage diagnosis of kidney diseases, without the use of contrast agents for reduced tissue retention and toxicity.
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Affiliation(s)
- Xianchun Zeng
- Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China; Department of Radiology, Michigan State University, East Lansing, MI, USA
| | - Shuangtao Ma
- Department of Medicine, Michigan State University, East Lansing, MI, USA
| | - John M Kruger
- Veterinary Medical Center, Michigan State University, East Lansing, MI, USA
| | - Rongpin Wang
- Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Xiaobo Tan
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, USA
| | - Chunqi Qian
- Department of Radiology, Michigan State University, East Lansing, MI, USA.
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Abstract
Kidney donors face a small but definite risk of end-stage renal disease 15 to 30 years postdonation. The development of proteinuria, hypertension with gradual decrease in kidney function in the donor after surgical resection of 1 kidney, has been attributed to hyperfiltration. Genetic variations, physiological adaptations, and comorbidities exacerbate the hyperfiltration-induced loss of kidney function in the years after donation. A focus on glomerular hemodynamics and capillary pressure has led to the development of drugs that target the renin-angiotensin-aldosterone system (RAAS), but these agents yield mixed results in transplant recipients and donors. Recent work on glomerular biomechanical forces highlights the differential effects of tensile stress and fluid flow shear stress (FFSS) from hyperfiltration. Capillary wall stretch due to glomerular capillary pressure increases tensile stress on podocyte foot processes that cover the capillary. In parallel, increased flow of the ultrafiltrate due to single-nephron glomerular filtration rate elevates FFSS on the podocyte cell body. Although tensile stress invokes the RAAS, FFSS predominantly activates the cyclooxygenase 2-prostaglandin E2-EP2 receptor axis. Distinguishing these 2 mechanisms is critical, as current therapeutic approaches focus on the RAAS system. A better understanding of the biomechanical forces can lead to novel therapeutic agents to target FFSS through the cyclooxygenase 2-prostaglandin E2-EP2 receptor axis in hyperfiltration-mediated injury. We present an overview of several aspects of the risk to transplant donors and discuss the relevance of FFSS in podocyte injury, loss of glomerular barrier function leading to albuminuria and gradual loss of renal function, and potential therapeutic strategies to mitigate hyperfiltration-mediated injury to the remaining kidney.
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30
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Effect of recipient-donor sex and weight mismatch on graft survival after deceased donor renal transplantation. PLoS One 2019; 14:e0214048. [PMID: 30925158 PMCID: PMC6440625 DOI: 10.1371/journal.pone.0214048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/06/2019] [Indexed: 12/05/2022] Open
Abstract
This study evaluated the combined effect of recipient-to-donor weight and sex mismatch after deceased-donor renal transplantation in a German transplant cohort and the evolution of recipient-to-donor weight difference over a 13-year observation period. The association of absolute weight and sex difference with graft failure was explored in an outpatient cohort of deceased-donor transplant recipients who underwent kidney transplantation between 2000 and 2012. Graft failure was defined as repeated need for dialysis or death with a functioning graft. Recipient and donor sex pairings were classified as sex concordant (MDMR/FDFR) or discordant (MDFR/FDMR). These classes were further stratified into four groups according to recipient-to-donor weight mismatch ≥10 kg (recipient > donor) or <10 kg (recipient < donor). Multivariable Cox proportional hazards models were applied to evaluate the time to graft loss adjusting for donor, immunologic, surgical, organizational, and recipient predictors. Sex-concordant transplant pairings <10 kg weight difference served as the reference group. Among 826 transplant recipients, 154 developed graft failure (18.6%). Median graft survival time was 3.9 years; first quartile (0.2–1.2), second quartile (1.2–2.9), third quartile (2.9–5.8), and fourth quartile (5.8–12.4). After multivariable adjustment, the highest relative hazard for graft failure was observed for sex-discordant transplant pairings with a ≥10 kg weight difference between recipient and donor (compared to the reference group MDMR/FDFR with weight difference <10 kg, MDMR/FDFR with weight difference ≥10 kg, hazard ratio 1.86, 95% confidence interval 1.07–3.32—p = 0.029; MDFR/FDMR with weight difference <10 kg, hazard ratio 1.14, 95% confidence interval 0.78–1.68—p = 0.507, and MDFR/FDMR with weight difference ≥10 kg, hazard ratio 2.00, 95% confidence interval 1.15–3.48—p = 0.014). A recipient-to-donor weight mismatch of ≥10 kg was associated with an increased risk of graft loss or recipient death with a functioning graft. Concurrent sex discordance seemed to enhance this effect as indicated by an increase in the hazard ratio. We detected no significant tendency for increasing recipient-to-donor weight differences from 2000 to 2012.
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31
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Huang J, Brenna C, Khan AUM, Daniele C, Rudolf R, Heuveline V, Gretz N. A cationic near infrared fluorescent agent and ethyl-cinnamate tissue clearing protocol for vascular staining and imaging. Sci Rep 2019; 9:521. [PMID: 30679514 PMCID: PMC6345820 DOI: 10.1038/s41598-018-36741-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 11/23/2018] [Indexed: 12/20/2022] Open
Abstract
Understanding vascular structures and dysfunction is a fundamental challenge. This task has been approached by using traditional methodologies such as microscopic computed tomography and magnetic resonance imaging. Both techniques are not only expensive but also time-consuming. Here, we present a new method for visualizing vascular structures in different organs in an efficient manner. A cationic near infrared (NIR) fluorescent dye was developed with attractive features to specifically stain blood vessels. Furthermore, we refined the process of organ staining and harvesting by retrograde perfusion and optimized the subsequent dehydration and clearing process by the use of an automatic tissue processor and a non-toxic substance, ethyl-cinnamate. Using this approach, the time interval between organ harvesting and microscopic analysis can be reduced from day(s) or weeks to 4 hours. Finally, we have demonstrated that the new NIR fluorescent agent in combination with confocal or light-sheet microscopy can be efficiently used for visualization of vascular structures, such as the blood vessels in different organs e.g. glomeruli in kidneys, with an extremely high resolution. Our approach facilitates the development of automatic image processing and the quantitative analysis to study vascular and kidney diseases.
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Affiliation(s)
- Jiaguo Huang
- Medical Research Center, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,Institute for Medical Technology, University of Heidelberg and University of Applied Sciences, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Cinzia Brenna
- Medical Research Center, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,Institute for Medical Technology, University of Heidelberg and University of Applied Sciences, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Arif Ul Maula Khan
- Medical Research Center, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,Institute for Medical Technology, University of Heidelberg and University of Applied Sciences, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Cristina Daniele
- Medical Research Center, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,Institute for Medical Technology, University of Heidelberg and University of Applied Sciences, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Rüdiger Rudolf
- Institute for Medical Technology, University of Heidelberg and University of Applied Sciences, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, 68163, Mannheim, Germany
| | - Vincent Heuveline
- Director of the Computing Centre, Heidelberg University, Im Neuenheimer Feld 293, 69120, Heidelberg, Germany
| | - Norbert Gretz
- Medical Research Center, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany. .,Institute for Medical Technology, University of Heidelberg and University of Applied Sciences, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
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32
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Romoli S, Angelotti ML, Antonelli G, Kumar Vr S, Mulay SR, Desai J, Anguiano Gomez L, Thomasova D, Eulberg D, Klussmann S, Melica ME, Conte C, Lombardi D, Lasagni L, Anders HJ, Romagnani P. CXCL12 blockade preferentially regenerates lost podocytes in cortical nephrons by targeting an intrinsic podocyte-progenitor feedback mechanism. Kidney Int 2018; 94:1111-1126. [PMID: 30385042 PMCID: PMC6251974 DOI: 10.1016/j.kint.2018.08.013] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 08/01/2018] [Accepted: 08/09/2018] [Indexed: 01/10/2023]
Abstract
Insufficient podocyte regeneration after injury is a central pathomechanism of glomerulosclerosis and chronic kidney disease. Podocytes constitutively secrete the chemokine CXCL12, which is known to regulate homing and activation of stem cells; hence we hypothesized a similar effect of CXCL12 on podocyte progenitors. CXCL12 blockade increased podocyte numbers and attenuated proteinuria in mice with Adriamycin-induced nephropathy. Similar studies in lineage-tracing mice revealed enhanced de novo podocyte formation from parietal epithelial cells in the setting of CXCL12 blockade. Super-resolution microscopy documented full integration of these progenitor-derived podocytes into the glomerular filtration barrier, interdigitating with tertiary foot processes of neighboring podocytes. Quantitative 3D analysis revealed that conventional 2D analysis underestimated the numbers of progenitor-derived podocytes. The 3D analysis also demonstrated differences between juxtamedullary and cortical nephrons in both progenitor endowment and Adriamycin-induced podocyte loss, with more robust podocyte regeneration in cortical nephrons with CXCL12 blockade. Finally, we found that delayed CXCL12 inhibition still had protective effects. In vitro studies found that CXCL12 inhibition uncoupled Notch signaling in podocyte progenitors. These data suggest that CXCL12-driven podocyte-progenitor feedback maintains progenitor quiescence during homeostasis, but also limits their intrinsic capacity to regenerate lost podocytes, especially in cortical nephrons. CXCL12 inhibition could be an innovative therapeutic strategy in glomerular disorders.
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Affiliation(s)
- Simone Romoli
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany
| | - Maria Lucia Angelotti
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Giulia Antonelli
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Santhosh Kumar Vr
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany
| | - Shrikant R Mulay
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany
| | - Jyaysi Desai
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany
| | | | - Dana Thomasova
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany
| | | | | | - Maria Elena Melica
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Carolina Conte
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Duccio Lombardi
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Laura Lasagni
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Hans-Joachim Anders
- Renal Division, Department of Medicine IV, University Hospital, Munich, Germany.
| | - Paola Romagnani
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy.
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33
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Xie L, Koukos G, Barck K, Foreman O, Lee WP, Brendza R, Eastham-Anderson J, McKenzie BS, Peterson A, Carano RAD. Micro-CT imaging and structural analysis of glomeruli in a model of Adriamycin-induced nephropathy. Am J Physiol Renal Physiol 2018; 316:F76-F89. [PMID: 30256127 DOI: 10.1152/ajprenal.00331.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glomeruli number and size are important for determining the pathogenesis of glomerular disease, chronic kidney disease, and hypertension. Moreover, renal injury can occur in specific cortical layers and alter glomerular spatial distribution. In this study, we present a comprehensive structural analysis of glomeruli in a model of Adriamycin (doxorubicin) nephropathy. Glomeruli are imaged (micro-CT at 10 × 10 × 10 μm3) in kidney specimens from C57Bl/6 mouse cohorts: control treated with saline ( n = 9) and Adriamycin treated with 20 mg/kg Adriamycin ( n = 7). Several indices were examined, including glomerular number, glomerular volume, glomerular volume heterogeneity, and spatial density at each glomerulus and in each cortical layer (superficial, midcortical, and juxtamedullary). In the Adriamycin-treated animals, glomerular number decreased significantly in the left kidney [control: 8,298 ± 221, Adriamycin: 6,781 ± 630 (mean ± SE)] and right kidney (control: 7,317 ± 367, Adriamycin: 5,522 ± 508), and glomerular volume heterogeneity increased significantly in the left kidney (control: 0.642 ± 0.015, Adriamycin: 0.786 ± 0.018) and right kidney (control: 0.739 ± 0.016, Adriamycin: 0.937 ± 0.023). Glomerular spatial density was not affected. Glomerular volume heterogeneity increased significantly in the superficial and midcortical layers of the Adriamycin cohort. Adriamycin did not affect glomerular volume or density metrics in the juxtamedullary region, suggesting a compensatory mechanism of juxtamedullary glomeruli to injury in the outer cortical layers. Left/right asymmetry was observed in kidney size and various glomeruli metrics. The methods presented here can be used to evaluate renal disease models with subtle changes in glomerular endowment locally or across the entire kidney, and they provide an imaging tool to investigate diverse interventions and therapeutic drugs.
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Affiliation(s)
- Luke Xie
- Biomedical Imaging, Genentech, South San Francisco, California
| | - Georgios Koukos
- Molecular Biology, Genentech, South San Francisco, California
| | - Kai Barck
- Biomedical Imaging, Genentech, South San Francisco, California
| | - Oded Foreman
- Pathology, Genentech, South San Francisco, California
| | - Wyne P Lee
- Translation Immunology, Genentech, South San Francisco, California
| | - Robert Brendza
- Neuroscience, Genentech, South San Francisco, California
| | | | - Brent S McKenzie
- Translation Immunology, Genentech, South San Francisco, California
| | - Andrew Peterson
- Molecular Biology, Genentech, South San Francisco, California
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Abstract
PURPOSE OF REVIEW For more than a century, kidney microscopic imaging was driven by the need for greater and greater resolution. This was in part provided by the analysis of thinner tissue sections. As a result, most kidney morphometry was performed in 'two' dimensions, largely ignoring the three-dimensionality of kidney tissue and cells. Although stereological techniques address this issue, they have generally been considered laborious and expensive and thereby unattractive for routine use. RECENT FINDINGS The past 2 decades have witnessed the development of optical clearing techniques, which enables visualization of thick slices of kidney tissue and even whole kidneys. This review describes the three main optical clearing strategies (solvent-based, aqueous-based and hydrogel embedding) with their respective advantages and disadvantages. We also describe how optical clearing provides new approaches to kidney morphometrics, including general kidney morphology (i.e. identification and quantitation of atubular glomeruli), glomerular numbers and volumes, numbers of specific glomerular cells (i.e. podocytes) and cell-specific stress-related changes (i.e. foot process effacement). SUMMARY The new clearing and morphometric approaches described in this review provide a new toolbox for imaging and quantification of kidney microanatomy. These approaches will make it easier to visualize the three-dimensional microanatomy of the kidney and decrease our reliance on biased two-dimensional morphometric techniques and time-consuming stereological approaches. They will also accelerate our research of structure-function relations in the healthy and diseased kidney.
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Abstract
Life with a solitary functioning kidney (SFK) may be different from that when born with two kidneys. Based on the hyperfiltration hypothesis, a SFK may lead to glomerular damage with hypertension, albuminuria and progression towards end-stage renal disease. As the prognosis of kidney donors was considered to be very good, having a SFK has been considered to be a benign condition. In contrast, our research group has demonstrated that being born with or acquiring a SFK in childhood results in renal injury before adulthood in over 50% of those affected. Most congenital cases will be detected during antenatal ultrasound screening, but up to 38% of cases of unilateral renal agenesis are missed. In about 25-50% of cases of antenatally detected SFK there will be signs of hypertrophy, which could indicate additional nephron formation and is associated with a somewhat reduced risk of renal injury. Additional renal and extrarenal anomalies are frequently detected and may denote a genetic cause for the SFK, even though for the majority of cases no explanation can (yet) be found. The ongoing glomerular hyperfiltration results in renal injury, for which early markers are lacking. Individuals with SFK should avoid obesity and excessive salt intake to limit additional hyperfiltration. As conditions like hypertension, albuminuria and a mildly reduced glomerular filtration rate generally do not result in specific complaints but may pose a threat to long-term health, screening for renal injury in any individual with a SFK would appear to be imperative, starting from infancy. With early treatment, secondary consequences may be diminished, thereby providing the optimal life for anyone born with a SFK.
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36
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Charlton JR, Chevalier RL. Developmental Origins of CKD: Big Problems From Small Packages. Am J Kidney Dis 2018; 71:3-5. [DOI: 10.1053/j.ajkd.2017.08.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 08/27/2017] [Indexed: 11/11/2022]
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37
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Baldelomar EJ, Charlton JR, Beeman SC, Bennett KM. Measuring rat kidney glomerular number and size in vivo with MRI. Am J Physiol Renal Physiol 2017; 314:F399-F406. [PMID: 29092847 DOI: 10.1152/ajprenal.00399.2017] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
number is highly variable in humans and is thought to play an important role in renal health. Chronic kidney disease (CKD) is the result of too few nephrons to maintain homeostasis. Currently, nephron number can only be determined invasively or as a terminal assessment. Due to a lack of tools to measure and track nephron number in the living, the early stages of CKD often go unrecognized, preventing early intervention that might halt the progression of CKD. In this work, we present a technique to directly measure glomerular number ( Nglom) and volume in vivo in the rat kidney ( n = 8) using MRI enhanced with the novel contrast agent cationized ferritin (CFE-MRI). Adult male rats were administered intravenous cationized ferritin (CF) and imaged in vivo with MRI. Glomerular number was measured and each glomerulus was spatially mapped in 3D in the image. Mean apparent glomerular volume (a Vglom) and intrarenal distribution of the individual glomerular volume (IGV), were also measured. These metrics were compared between images of the same kidneys scanned in vivo and ex vivo with CFE-MRI. In vivo Nglom and a Vglom correlated to ex vivo metrics within the same kidneys and were within 10% of Nglom and a Vglom previously validated by stereologic methods. This is the first report of direct in vivo measurements of Nglom and a Vglom, introducing an opportunity to investigate mechanisms of renal disease progression and therapeutic response over time.
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Affiliation(s)
| | - Jennifer R Charlton
- University of Virginia , Department of Pediatrics, Charlottesville, Virginia
| | - Scott C Beeman
- Washington University School of Medicine , Mallinckrodt Institute of Radiology, St. Louis, Missouri
| | - Kevin M Bennett
- University of Hawaii at Manoa, Department of Biology , Honolulu, Hawaii
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38
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Geraci S, Chacon-Caldera J, Cullen-McEwen L, Schad LR, Sticht C, Puelles VG, Bertram JF, Gretz N. Combining new tools to assess renal function and morphology: a holistic approach to study the effects of aging and a congenital nephron deficit. Am J Physiol Renal Physiol 2017; 313:F576-F584. [PMID: 28490528 DOI: 10.1152/ajprenal.00329.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 04/28/2017] [Accepted: 05/09/2017] [Indexed: 01/17/2023] Open
Abstract
Recently, new methods for assessing renal function in conscious mice (transcutaneous assessment) and for counting and sizing all glomeruli in whole kidneys (MRI) have been described. In the present study, these methods were used to assess renal structure and function in aging mice, and in mice born with a congenital low-nephron endowment. Age-related nephron loss was analyzed in adult C57BL/6 mice (10-50 wk of age), and congenital nephron deficit was assessed in glial cell line-derived neurotrophic factor heterozygous (GDNF HET)-null mutant mice. Renal function was measured through the transcutaneous quantitation of fluorescein isothiocyanate-sinistrin half-life (t1/2) in conscious mice. MRI was used to image, count, and size cationic-ferritin labeled glomeruli in whole kidneys ex vivo. Design-based stereology was used to validate the MRI measurements of glomerular number and mean volume. In adult C57BL/6 mice, older age was associated with fewer and larger glomeruli, and a rightward shift in the glomerular size distribution. These changes coincided with a decrease in renal function. GNDF HET mice had a congenital nephron deficit that was associated with glomerular hypertrophy and exacerbated by aging. These findings suggest that glomerular hypertrophy and hyperfiltration are compensatory processes that can occur in conjunction with both age-related nephron loss and congenital nephron deficiency. The combination of measurement of renal function in conscious animals and quantitation of glomerular number, volume, and volume distribution provides a powerful new tool for investigating aspects of renal aging and functional changes.
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Affiliation(s)
- Stefania Geraci
- Medical Research Centre, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Jorge Chacon-Caldera
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany; and
| | - Luise Cullen-McEwen
- Cardiovascular Program, Monash Biomedicine Discovery Institute, and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany; and
| | - Carsten Sticht
- Medical Research Centre, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Victor G Puelles
- Cardiovascular Program, Monash Biomedicine Discovery Institute, and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
| | - John F Bertram
- Cardiovascular Program, Monash Biomedicine Discovery Institute, and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
| | - Norbert Gretz
- Medical Research Centre, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany;
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39
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Chevalier RL. Evolutionary Nephrology. Kidney Int Rep 2017; 2:302-317. [PMID: 28845468 PMCID: PMC5568830 DOI: 10.1016/j.ekir.2017.01.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 01/11/2017] [Accepted: 01/25/2017] [Indexed: 01/05/2023] Open
Abstract
Progressive kidney disease follows nephron loss, hyperfiltration, and incomplete repair, a process described as "maladaptive." In the past 20 years, a new discipline has emerged that expands research horizons: evolutionary medicine. In contrast to physiologic (homeostatic) adaptation, evolutionary adaptation is the result of reproductive success that reflects natural selection. Evolutionary explanations for physiologically maladaptive responses can emerge from mismatch of the phenotype with environment or evolutionary tradeoffs. Evolutionary adaptation to a terrestrial environment resulted in a vulnerable energy-consuming renal tubule and a hypoxic, hyperosmolar microenvironment. Natural selection favors successful energy investment strategy: energy is allocated to maintenance of nephron integrity through reproductive years, but this declines with increasing senescence after ~40 years of age. Risk factors for chronic kidney disease include restricted fetal growth or preterm birth (life history tradeoff resulting in fewer nephrons), evolutionary selection for APOL1 mutations (that provide resistance to trypanosome infection, a tradeoff), and modern life experience (Western diet mismatch leading to diabetes and hypertension). Current advances in genomics, epigenetics, and developmental biology have revealed proximate causes of kidney disease, but attempts to slow kidney disease remain elusive. Evolutionary medicine provides a complementary approach by addressing ultimate causes of kidney disease. Marked variation in nephron number at birth, nephron heterogeneity, and changing susceptibility to kidney injury throughout life history are the result of evolutionary processes. Combined application of molecular genetics, evolutionary developmental biology (evo-devo), developmental programming and life history theory may yield new strategies for prevention and treatment of chronic kidney disease.
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Affiliation(s)
- Robert L. Chevalier
- Department of Pediatrics, The University of Virginia, Charlottesville, Virginia, USA
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40
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Affiliation(s)
- Jennifer R Charlton
- Department of Pediatrics, Division of Nephrology, University of Virginia School of Medicine, Charlottesville, Virginia; and
| | - Carolyn L Abitbol
- Department of Pediatrics, Division of Pediatric Nephrology, University of Miami Miller School of Medicine, Miami, Florida
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41
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Abstract
Hypertension and chronic kidney disease (CKD) have a significant impact on global morbidity and mortality. The Low Birth Weight and Nephron Number Working Group has prepared a consensus document aimed to address the relatively neglected issue for the developmental programming of hypertension and CKD. It emerged from a workshop held on April 2, 2016, including eminent internationally recognized experts in the field of obstetrics, neonatology, and nephrology. Through multidisciplinary engagement, the goal of the workshop was to highlight the association between fetal and childhood development and an increased risk of adult diseases, focusing on hypertension and CKD, and to suggest possible practical solutions for the future. The recommendations for action of the consensus workshop are the results of combined clinical experience, shared research expertise, and a review of the literature. They highlight the need to act early to prevent CKD and other related noncommunicable diseases later in life by reducing low birth weight, small for gestational age, prematurity, and low nephron numbers at birth through coordinated interventions. Meeting the current unmet needs would help to define the most cost-effective strategies and to optimize interventions to limit or interrupt the developmental programming cycle of CKD later in life, especially in the poorest part of the world.
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42
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Wang X, Garrett MR. Nephron number, hypertension, and CKD: physiological and genetic insight from humans and animal models. Physiol Genomics 2017; 49:180-192. [PMID: 28130427 DOI: 10.1152/physiolgenomics.00098.2016] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The kidneys play a vital role in the excretion of waste products and the regulation of electrolytes, maintenance of acid-base balance, regulation of blood pressure, and production of several hormones. Any alteration in the structure of the nephron (basic functional unit of the kidney) can have a major impact on the kidney's ability to work efficiently. Progressive decline in kidney function can lead to serious illness and ultimately death if not treated by dialysis or transplantation. While there have been numerous studies that implicate lower nephron numbers as being an important factor in influencing susceptibility to developing hypertension and chronic kidney disease, a direct association has been difficult to establish because of three main limitations: 1) the large variation in nephron number observed in the human population; 2) no established reliable noninvasive methods to determine nephron complement; and 3) to date, nephron measurements have been done after death, which doesn't adequately account for potential loss of nephrons with age or disease. In this review, we will provide an overview of kidney structure/function, discuss the current literature for both humans and other species linking nephron deficiency and cardio-renal complications, as well as describe the major molecular signaling factors involved in nephrogenesis that modulate variation in nephron number. As more detailed knowledge about the molecular determinants of nephron development and the role of nephron endowment in the cardio-renal system is obtained, it will hopefully provide clinicians the ability to accurately identify people at risk to develop CKD/hypertension and lead to a shift in patient care from disease treatment to prevention.
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Affiliation(s)
- Xuexiang Wang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - Michael R Garrett
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and .,Department of Medicine (Nephrology) and Pediatrics (Genetics), University of Mississippi Medical Center, Jackson, Mississippi
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43
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Abstract
New nephrons are induced by the interaction between mesenchymal progenitor cells and collecting duct tips, both of which are located at the outer edge of the kidney. This leading edge of active nephron induction is known as the nephrogenic zone. Cell populations found within this zone include collecting duct tips, cap mesenchyme cells, pretubular aggregates, nephrogenic zone interstitium, hemoendothelial progenitor cells, and macrophages. The close association of these dynamic progenitor cell compartments enables the intricate and synchronized patterning of the epithelial and the vascular components of the nephron. Understanding signaling interactions between the distinct progenitor cells of the nephrogenic zone are essential to determining the basis for new nephron formation, an important goal in regenerative medicine. A variety of technologies have been applied to define essential signaling pathways, including organ culture, mouse genetics, and primary cell culture. This chapter provides an overview of essential signaling pathways and discusses how these may be integrated.
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Afridi MJ, Ross A, Liu X, Bennewitz MF, Shuboni DD, Shapiro EM. Intelligent and automatic in vivo detection and quantification of transplanted cells in MRI. Magn Reson Med 2016; 78:1991-2002. [PMID: 28019017 DOI: 10.1002/mrm.26571] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 10/19/2016] [Accepted: 11/16/2016] [Indexed: 12/30/2022]
Abstract
PURPOSE Magnetic resonance imaging (MRI)-based cell tracking has emerged as a useful tool for identifying the location of transplanted cells, and even their migration. Magnetically labeled cells appear as dark contrast in T2*-weighted MRI, with sensitivities of individual cells. One key hurdle to the widespread use of MRI-based cell tracking is the inability to determine the number of transplanted cells based on this contrast feature. In the case of single cell detection, manual enumeration of spots in three-dimensional (3D) MRI in principle is possible; however, it is a tedious and time-consuming task that is prone to subjectivity and inaccuracy on a large scale. This research presents the first comprehensive study on how a computer-based intelligent, automatic, and accurate cell quantification approach can be designed for spot detection in MRI scans. METHODS Magnetically labeled mesenchymal stem cells (MSCs) were transplanted into rats using an intracardiac injection, accomplishing single cell seeding in the brain. T2*-weighted MRI of these rat brains were performed where labeled MSCs appeared as spots. Using machine learning and computer vision paradigms, approaches were designed to systematically explore the possibility of automatic detection of these spots in MRI. Experiments were validated against known in vitro scenarios. RESULTS Using the proposed deep convolutional neural network (CNN) architecture, an in vivo accuracy up to 97.3% and in vitro accuracy of up to 99.8% was achieved for automated spot detection in MRI data. CONCLUSION The proposed approach for automatic quantification of MRI-based cell tracking will facilitate the use of MRI in large-scale cell therapy studies. Magn Reson Med 78:1991-2002, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Muhammad Jamal Afridi
- Department of Computer Science and Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Arun Ross
- Department of Computer Science and Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Xiaoming Liu
- Department of Computer Science and Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Margaret F Bennewitz
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Dorela D Shuboni
- Department of Radiology, Michigan State University, East Lansing, Michigan, USA
| | - Erik M Shapiro
- Department of Radiology, Michigan State University, East Lansing, Michigan, USA
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45
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Assessment of kidney function in preterm infants: lifelong implications. Pediatr Nephrol 2016; 31:2213-2222. [PMID: 26846786 DOI: 10.1007/s00467-016-3320-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 12/20/2015] [Accepted: 12/31/2015] [Indexed: 01/18/2023]
Abstract
This educational review will highlight the historical and contemporary references that establish a basic understanding of measurements of kidney function in the neonate and its relevance for the life of an individual. Importantly, the differential renal function of preterm infants relative to term infants has become paramount with the increased viability of preterm infants and the realization that kidney function is associated with gestational age. Moreover, neonatal kidney function is primarily associated with absolute renal mass and hemodynamic stability. Neonatal kidney function and its early developmental progression predict lifelong cardiovascular and renal disease risks. Validation of estimation equations of kidney function in this population has provided important reference data for other investigations and a clinical basis for prospective and longitudinal follow-up. Future research should be directed towards a better understanding of surrogate markers of kidney function from infancy through adulthood. Pediatric nephrologists should be aware of the developmental aspects of kidney function including the importance of the congenital nephron endowment and the preservation of kidney function throughout a lifetime. • Nephrogenesis occurs in utero in concert with other organ systems by branching morphogenesis, including the lungs, pancreas, and vascular tree, with over 60 % of nephrons being formed during the last trimester. • Infants born preterm before 36 weeks' gestation are in active nephrogenesis and are at increased risk of having a decreased nephron endowment from prenatal and postnatal genetic and epigenetic hazards that will impact the patient for a lifetime. • Post-natal adaptation of kidney function is directly proportional to the number of perfused nephrons, estimated by total kidney volume (TKV), mean arterial pressure (MAP), and gestational age. • Accurate measurement of glomerular filtration rate (GFR) in infants is problematic due to the unavailability of the gold standard inulin. The traditional use of creatinine to estimate GFR is unreliable in preterm infants due to its tubular reabsorption by immature kidneys and its dependence on muscle mass as an endogenous marker. Alternative endogenous markers to estimate GFR are cystatin C and beta trace protein (BTP). • Long-term follow-up of renal function in those born preterm should be life long and should include assessment of GFR, total kidney volume (TKV) relative to body surface area (BSA), and cardiovascular risks including hypertension and vascular stiffness.
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46
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Xie L, Bennett KM, Liu C, Johnson GA, Zhang JL, Lee VS. MRI tools for assessment of microstructure and nephron function of the kidney. Am J Physiol Renal Physiol 2016; 311:F1109-F1124. [PMID: 27630064 DOI: 10.1152/ajprenal.00134.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 09/08/2016] [Indexed: 12/13/2022] Open
Abstract
MRI can provide excellent detail of renal structure and function. Recently, novel MR contrast mechanisms and imaging tools have been developed to evaluate microscopic kidney structures including the tubules and glomeruli. Quantitative MRI can assess local tubular function and is able to determine the concentrating mechanism of the kidney noninvasively in real time. Measuring single nephron function is now a near possibility. In parallel to advancing imaging techniques for kidney microstructure is a need to carefully understand the relationship between the local source of MRI contrast and the underlying physiological change. The development of these imaging markers can impact the accurate diagnosis and treatment of kidney disease. This study reviews the novel tools to examine kidney microstructure and local function and demonstrates the application of these methods in renal pathophysiology.
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Affiliation(s)
- Luke Xie
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, Utah;
| | - Kevin M Bennett
- Department of Biology, University of Hawaii at Manoa, Honolulu, Hawaii
| | - Chunlei Liu
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina; and.,Brain Imaging and Analysis Center, Duke University Medical Center, Durham, North Carolina
| | - G Allan Johnson
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina; and
| | - Jeff Lei Zhang
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, Utah
| | - Vivian S Lee
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, Utah
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47
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Klingberg A, Hasenberg A, Ludwig-Portugall I, Medyukhina A, Männ L, Brenzel A, Engel DR, Figge MT, Kurts C, Gunzer M. Fully Automated Evaluation of Total Glomerular Number and Capillary Tuft Size in Nephritic Kidneys Using Lightsheet Microscopy. J Am Soc Nephrol 2016; 28:452-459. [PMID: 27487796 DOI: 10.1681/asn.2016020232] [Citation(s) in RCA: 219] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 07/08/2016] [Indexed: 12/19/2022] Open
Abstract
The total number of glomeruli is a fundamental parameter of kidney function but very difficult to determine using standard methodology. Here, we counted all individual glomeruli in murine kidneys and sized the capillary tufts by combining in vivo fluorescence labeling of endothelial cells, a novel tissue-clearing technique, lightsheet microscopy, and automated registration by image analysis. Total hands-on time per organ was <1 hour, and automated counting/sizing was finished in <3 hours. We also investigated the novel use of ethyl-3-phenylprop-2-enoate (ethyl cinnamate) as a nontoxic solvent-based clearing reagent that can be handled without specific safety measures. Ethyl cinnamate rapidly cleared all tested organs, including calcified bone, but the fluorescence of proteins and immunohistochemical labels was maintained over weeks. Using ethyl cinnamate-cleared kidneys, we also quantified the average creatinine clearance rate per glomerulus. This parameter decreased in the first week of experimental nephrotoxic nephritis, whereas reduction in glomerular numbers occurred much later. Our approach delivers fundamental parameters of renal function, and because of its ease of use and speed, it is suitable for high-throughput analysis and could greatly facilitate studies of the effect of kidney diseases on whole-organ physiology.
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Affiliation(s)
- Anika Klingberg
- Institute for Experimental Immunology and Imaging, University Hospital, University Duisburg-Essen, Essen, Germany
| | - Anja Hasenberg
- Institute for Experimental Immunology and Imaging, University Hospital, University Duisburg-Essen, Essen, Germany
| | - Isis Ludwig-Portugall
- Institute for Experimental Immunology, Rheinische-Friedrichs-Wilhelms University of Bonn, Bonn, Germany
| | - Anna Medyukhina
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Leibniz-Association, Jena, Germany; and
| | - Linda Männ
- Institute for Experimental Immunology and Imaging, University Hospital, University Duisburg-Essen, Essen, Germany
| | - Alexandra Brenzel
- Institute for Experimental Immunology and Imaging, University Hospital, University Duisburg-Essen, Essen, Germany
| | - Daniel R Engel
- Institute for Experimental Immunology and Imaging, University Hospital, University Duisburg-Essen, Essen, Germany
| | - Marc Thilo Figge
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Leibniz-Association, Jena, Germany; and.,Friedrich Schiller University Jena, Jena, Germany
| | - Christian Kurts
- Institute for Experimental Immunology, Rheinische-Friedrichs-Wilhelms University of Bonn, Bonn, Germany
| | - Matthias Gunzer
- Institute for Experimental Immunology and Imaging, University Hospital, University Duisburg-Essen, Essen, Germany;
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48
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Zhang M, Wu T, Beeman SC, Cullen-McEwen L, Bertram JF, Charlton JR, Baldelomar E, Bennett KM. Efficient Small Blob Detection Based on Local Convexity, Intensity and Shape Information. IEEE TRANSACTIONS ON MEDICAL IMAGING 2016; 35:1127-1137. [PMID: 26685229 PMCID: PMC6991892 DOI: 10.1109/tmi.2015.2509463] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The identification of small structures (blobs) from medical images to quantify clinically relevant features, such as size and shape, is important in many medical applications. One particular application explored here is the automated detection of kidney glomeruli after targeted contrast enhancement and magnetic resonance imaging. We propose a computationally efficient algorithm, termed the Hessian-based Difference of Gaussians (HDoG), to segment small blobs (e.g., glomeruli from kidney) from 3D medical images based on local convexity, intensity and shape information. The image is first smoothed and pre-segmented into small blob candidate regions based on local convexity. Two novel 3D regional features (regional blobness and regional flatness) are then extracted from the candidate regions. Together with regional intensity, the three features are used in an unsupervised learning algorithm for auto post-pruning. HDoG is first validated in a 2D form and compared with other three blob detectors from literature, which are generally for 2D images only. To test the detectability of blobs from 3D images, 240 sets of simulated images are rendered for scenarios mimicking the renal nephron distribution observed in contrast-enhanced, 3D MRI. The results show a satisfactory performance of HDoG in detecting large numbers of small blobs. Two sets of real kidney 3D MR images (6 rats, 3 human) are then used to validate the applicability of HDoG for glomeruli detection. By comparing MRI to stereological measurements, we verify that HDoG is a robust and efficient unsupervised technique for 3D blobs segmentation.
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49
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Hann BD, Baldelomar EJ, Charlton JR, Bennett KM. Measuring the intrarenal distribution of glomerular volumes from histological sections. Am J Physiol Renal Physiol 2016; 310:F1328-36. [PMID: 26984953 DOI: 10.1152/ajprenal.00382.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 03/11/2016] [Indexed: 11/22/2022] Open
Abstract
Glomerular volume is an important metric reflecting glomerular filtration surface area within the kidney. Glomerular hypertrophy, or increased glomerular volume, may be an important marker for renal stress. Current stereological techniques report the average glomerular volume (AVglom) within the kidney. These techniques cannot assess the spatial or regional heterogeneity common in developing renal pathology. Here, we report a novel "unfolding" technique to measure the actual distribution of individual glomerular volumes in a kidney from the two-dimensional glomerulus profiles observed by optical microscopy. The unfolding technique was first developed and tested for accuracy with simulations and then applied to measure the number of glomeruli (Nglom), AVglom, and intrarenal distribution of individual glomerular volume (IVglom) in the oligosyndactyl (Os/(+)) mouse model compared with wild-type (WT) controls. The Os/(+) mice had fewer and larger glomeruli than WT mice: Nglom was 12,126 ± 1,658 (glomeruli/kidney) in the WT mice and 5,516 ± 899 in the Os/(+) mice; AVglom was 2.01 ± 0.28 × 10(-4) mm(3) for the WT mice and 3.47 ± 0.35 × 10(-4) mm(3) for the Os/(+) mice. Comparing the glomerular volume distributions in Os/(+) and WT kidneys, we observed that the Os/(+) distribution peaked at a higher value of IVglom than the WT distribution peak, and glomeruli with a radius greater than 55 μm were more prevalent in the Os/(+) mice (3.4 ± 1.6% of total glomeruli vs. 0.6 ± 1.2% in WT). Finally, the largest profiles were more commonly found in the juxtamedullary region. Unfolding is a novel stereological technique that provides a new quantitative view of glomerular volume distribution in the individual kidney.
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Affiliation(s)
- Bradley D Hann
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, Hawaii
| | | | - Jennifer R Charlton
- Department of Pediatrics, Division of Nephrology, University of Virginia, Charlottesville, Virginia; and
| | - Kevin M Bennett
- Department of Biology, University of Hawaii at Manoa, Honolulu, Hawaii
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