1
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Wang D, Ferrell N. Transglutaminase-mediated stiffening of the glomerular basement membrane mitigates pressure-induced reductions in molecular sieving coefficient by reducing compression. Matrix Biol 2024; 130:47-55. [PMID: 38723871 DOI: 10.1016/j.matbio.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 04/30/2024] [Accepted: 05/06/2024] [Indexed: 06/03/2024]
Abstract
Proteinuria, the presence of high molecular weight proteins in the urine, is a primary indicator of chronic kidney disease. Proteinuria results from increased molecular permeability of the glomerular filtration barrier combined with saturation or defects in tubular protein reabsorption. Any solute that passes into the glomerular filtrate traverses the glomerular endothelium, the glomerular basement membrane, and the podocyte slit diaphragm. Damage to any layer of the filter has reciprocal effects on other layers to increase glomerular permeability. The GBM is thought to act as a compressible ultrafilter that has increased molecular selectivity with increased pressure due to compression that reduced the porosity of the GBM with increased pressure. In multiple forms of chronic kidney disease, crosslinking enzymes are upregulated and may act to increase GBM stiffness. Here we show that enzymatically crosslinking porcine GBM with transglutaminase increases the stiffness of the GBM and mitigates pressure-dependent reductions in molecular sieving coefficient. This was modeled mathematically using a modified membrane transport model accounting for GBM compression. Changes in the mechanical properties of the GBM may contribute to proteinuria through pressure-dependent effects on GBM porosity.
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Affiliation(s)
- Dan Wang
- Department of Internal Medicine, Division of Nephrology, The Ohio State University Wexner Medical Center, 1664 Neil Ave. 4th Floor, Suite 4100, Columbus, OH 43201, United States
| | - Nicholas Ferrell
- Department of Internal Medicine, Division of Nephrology, The Ohio State University Wexner Medical Center, 1664 Neil Ave. 4th Floor, Suite 4100, Columbus, OH 43201, United States.
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2
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Wang D, Ferrell N. In Vitro Models to Evaluate Molecular Permeability of the Kidney Filtration Barrier. Methods Mol Biol 2023; 2664:41-53. [PMID: 37423981 DOI: 10.1007/978-1-0716-3179-9_4] [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
The glomerular basement membrane (GBM) is an important component of the kidney filtration barrier. The ability to evaluate the molecular transport properties of the GBM and determining how changes in the structure, composition, and mechanical properties of the GBM regulate its size selective transport properties may provide additional insight into glomerular function. This chapter details a method for making in vitro models of the glomerular filtration barrier using animal-derived decellularized glomeruli. FITC-labelled Ficoll is used as a filtration probe to evaluate the molecular transport properties during passive diffusion and under applied pressure. These systems can serve as a platform to evaluate the molecular permeability of basement membrane systems using conditions that simulate normal or pathophysiological conditions.
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Affiliation(s)
- Dan Wang
- Department of Internal Medicine, Division of Nephrology, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Nicholas Ferrell
- Department of Internal Medicine, Division of Nephrology, Ohio State University Wexner Medical Center, Columbus, OH, USA.
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3
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Wang D, Sant S, Lawless C, Ferrell N. A kidney proximal tubule model to evaluate effects of basement membrane stiffening on renal tubular epithelial cells. Integr Biol (Camb) 2022; 14:171-183. [PMID: 36573280 DOI: 10.1093/intbio/zyac016] [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: 01/20/2022] [Revised: 09/21/2022] [Accepted: 11/06/2022] [Indexed: 12/28/2022]
Abstract
The kidney tubule consists of a single layer of epithelial cells supported by the tubular basement membrane (TBM), a thin layer of specialized extracellular matrix (ECM). The mechanical properties of the ECM are important for regulating a wide range of cell functions including proliferation, differentiation and cell survival. Increased ECM stiffness plays a role in promoting multiple pathological conditions including cancer, fibrosis and heart disease. How changes in TBM mechanics regulate tubular epithelial cell behavior is not fully understood. Here we introduce a cell culture system that utilizes in vivo-derived TBM to investigate cell-matrix interactions in kidney proximal tubule cells. Basement membrane mechanics was controlled using genipin, a biocompatibility crosslinker. Genipin modification resulted in a dose-dependent increase in matrix stiffness. Crosslinking had a marginal but statistically significant impact on the diffusive molecular transport properties of the TBM, likely due to a reduction in pore size. Both native and genipin-modified TBM substrates supported tubular epithelial cell growth. Cells were able to attach and proliferate to form confluent monolayers. Tubular epithelial cells polarized and assembled organized cell-cell junctions. Genipin modification had minimal impact on cell viability and proliferation. Genipin stiffened TBM increased gene expression of pro-fibrotic cytokines and altered gene expression for N-cadherin, a proximal tubular epithelial specific cell-cell junction marker. This work introduces a new cell culture model for cell-basement membrane mechanobiology studies that utilizes in vivo-derived basement membrane. We also demonstrate that TBM stiffening affects tubular epithelial cell function through altered gene expression of cell-specific differentiation markers and induced increased expression of pro-fibrotic growth factors.
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Affiliation(s)
- Dan Wang
- Department of Internal Medicine, Division of Nephrology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Snehal Sant
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Craig Lawless
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Nicholas Ferrell
- Department of Internal Medicine, Division of Nephrology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
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4
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Nonlinear elasticity of biological basement membrane revealed by rapid inflation and deflation. Proc Natl Acad Sci U S A 2021; 118:2022422118. [PMID: 33836598 PMCID: PMC7980462 DOI: 10.1073/pnas.2022422118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Basement membrane (BM) is a thin layer of extracellular matrix that surrounds most animal tissues, serving as a physical barrier while allowing nutrient exchange. Although they have important roles in tissue structural integrity, physical properties of BMs remain largely uncharacterized, which limits our understanding of their mechanical functions. Here, we perform pressure-controlled inflation and deflation to directly measure the nonlinear mechanics of BMs in situ. We show that the BMs behave as a permeable, hyperelastic material whose mechanical properties and permeability can be measured in a model-independent manner. Furthermore, we find that BMs exhibit a remarkable nonlinear stiffening behavior, in contrast to the reconstituted Matrigel. This nonlinear stiffening behavior helps the BMs to avoid the snap-through instability (or structural softening) widely observed during the inflation of most elastomeric balloons and thus maintain sufficient confining stress to the enclosed tissues during their growth.
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5
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Wang D, Sant S, Ferrell N. A Biomimetic In Vitro Model of the Kidney Filtration Barrier Using Tissue-Derived Glomerular Basement Membrane. Adv Healthc Mater 2021; 10:e2002275. [PMID: 34218528 DOI: 10.1002/adhm.202002275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 05/24/2021] [Indexed: 01/28/2023]
Abstract
The glomerular filtration barrier (GFB) filters the blood to remove toxins while retaining high molecular weight proteins in the circulation. The glomerular basement membrane (GBM) and podocytes, highly specialized epithelial cells, are critical components of the filtration barrier. The GBM serves as a physical barrier to passage of molecules into the filtrate. Podocytes adhere to the filtrate side of the GBM and further restrict passage of high molecular weight molecules into the filtrate. Here, a 3D cell culture model of the glomerular filtration barrier to evaluate the role of the GBM and podocytes in mediating molecular diffusion is developed. GBM is isolated from mammalian kidneys to recapitulate the composition and mechanics of the in vivo basement membrane. The GFB model exhibits molecular selectivity that is comparable to the in vivo filtration barrier. The GBM alone provides a stringent barrier to passage of albumin and Ficoll. Podocytes further restrict molecular diffusion. Damage to the GBM that is typical of diabetic kidney disease is simulated using hypochlorous acid and results in increased molecular diffusion. This system can serve as a platform to evaluate the effects of GBM damage, podocyte injury, and reciprocal effects of altered podocyte-GBM interactions on kidney microvascular permeability.
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Affiliation(s)
- Dan Wang
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, 1161 21st Ave. South, Nashville, TN, 37232, USA
| | - Snehal Sant
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, 1161 21st Ave. South, Nashville, TN, 37232, USA
| | - Nicholas Ferrell
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, 1161 21st Ave. South, Nashville, TN, 37232, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37235, USA
- Vanderbilt Center for Kidney Disease, S3223 Medical Center North, Nashville, TN, 37232, USA
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6
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Moeller MJ, Chia-Gil A. A step forward in understanding glomerular filtration. Nat Rev Nephrol 2020; 16:431-432. [PMID: 32601383 DOI: 10.1038/s41581-020-0313-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marcus J Moeller
- Department of Nephrology and Clinical Immunology, RWTH Aachen University Clinic, Aachen, Germany.
| | - Arnaldo Chia-Gil
- Department of Nephrology and Clinical Immunology, RWTH Aachen University Clinic, Aachen, Germany
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7
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Sueiras VM, Devaux F, Smith B, Lai J, Batchelor W, Likht NY, Moy VT, Ziebarth NM. Age-dependency of molecular diffusion in the human anterior lens capsule assessed using fluorescence recovery after photobleaching. Mol Vis 2019; 25:593-xxx. [PMID: 31741652 PMCID: PMC6828993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/12/2019] [Indexed: 11/03/2022] Open
Abstract
Purpose To quantify the partition coefficient and the diffusion coefficient of metal-carrier proteins in the human lens capsule as a function of age. Methods Whole lenses from human donors were incubated overnight in a solution of fluorescently labeled transferrin, albumin, or ceruloplasmin. In the central plane of the capsule thickness, fluorescence recovery after photobleaching (FRAP) experiments were conducted to measure the diffusion of the protein within the lens capsule. The anterior portion of the lens was recorded before the FRAP experiments to locate the boundaries of the anterior lens capsule and to measure the partition coefficient of the labeled proteins. The partition coefficient (P), the time to half maximum recovery of the fluorescent intensity (τ1/2), and the diffusion coefficient (D) for each protein were analyzed as a function of donor age. Results There was no statistically significant relationship between the half maximum recovery time or the diffusion coefficient and age for transferrin (molecular weight [MW]=79.5 kDa, τ1/2=17.26±4.840 s, D=0.17±0.05 μm2/s), serum albumin (MW=66.5 kDa, τ1/2=18.45±6.110 s, D=0.17±0.06 μm2/s), or ceruloplasmin (MW=120 kDa, τ1/2=36.57±5.660 s, D=0.08±0.01 μm2/s). As expected, the larger protein (ceruloplasmin) took longer to recover fluorescent intensity due to its slower movement within the lens capsule. The partition coefficient statistically significantly increased with age for each protein (Palbumin: 0.09-0.71, Pceruloplasmin: 0.42-0.95, Ptransferrin: 0.19-1.17). Conclusions The diffusion of heavy-metal protein carriers within the anterior lens capsule is not dependent on age, but it is dependent on the size of the protein. The permeability of the lens capsule to these heavy-metal protein carriers increases with age, suggesting that there will be a higher concentration of heavy metals in the older lens. This behavior may favor the formation of cataract, because heavy metals enhance protein oxidation through the Fenton reaction.
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Affiliation(s)
- Vivian M. Sueiras
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL
| | - Floriane Devaux
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL
| | - Benjamin Smith
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL
| | - James Lai
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL
| | - Wyndham Batchelor
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL
| | - Nikita Y. Likht
- Florida Lions Eye Bank, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL
| | - Vincent T. Moy
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL
| | - Noël M. Ziebarth
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL,Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL
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8
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Kuppe C, Rohlfs W, Grepl M, Schulte K, Veron D, Elger M, Sanden SK, Saritas T, Andrae J, Betsholtz C, Trautwein C, Hausmann R, Quaggin S, Bachmann S, Kriz W, Tufro A, Floege J, Moeller MJ. Inverse correlation between vascular endothelial growth factor back-filtration and capillary filtration pressures. Nephrol Dial Transplant 2019; 33:1514-1525. [PMID: 29635428 DOI: 10.1093/ndt/gfy057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 02/08/2018] [Indexed: 12/17/2022] Open
Abstract
Background Vascular endothelial growth factor A (VEGF) is an essential growth factor during glomerular development and postnatal homeostasis. VEGF is secreted in high amounts by podocytes into the primary urine, back-filtered across the glomerular capillary wall to act on endothelial cells. So far it has been assumed that VEGF back-filtration is driven at a constant rate exclusively by diffusion. Methods In the present work, glomerular VEGF back-filtration was investigated in vivo using a novel extended model based on endothelial fenestrations as surrogate marker for local VEGF concentrations. Single nephron glomerular filtration rate (SNGFR) and/or local filtration flux were manipulated by partial renal mass ablation, tubular ablation, and in transgenic mouse models of systemic or podocytic VEGF overexpression or reduction. Results Our study shows positive correlations between VEGF back-filtration and SNGFR as well as effective filtration rate under physiological conditions along individual glomerular capillaries in rodents and humans. Conclusion Our results suggest that an additional force drives VEGF back-filtration, potentially regulated by SNGFR.
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Affiliation(s)
- Christoph Kuppe
- Division of Nephrology and Immunology, RWTH Aachen University, Aachen, Germany
| | - Wilko Rohlfs
- Institute of Heat and Mass Transfer, RWTH Aachen University, Aachen, Germany
| | - Martin Grepl
- Numerical Mathematics, Faculty for Mathematics, Informatics and Natural Sciences, RWTH Aachen University, Aachen, Germany
| | - Kevin Schulte
- Division of Nephrology and Immunology, RWTH Aachen University, Aachen, Germany.,Department of Nephrology, University of Kiel, Kiel, Germany
| | - Delma Veron
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Marlies Elger
- Department of Anatomy and Developmental Biology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | | | - Turgay Saritas
- Division of Nephrology and Immunology, RWTH Aachen University, Aachen, Germany
| | - Johanna Andrae
- Department of Immunology, Genetics and Pathology, Uppsala University, Rudbeck Laboratory, Uppsala, Sweden
| | - Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Uppsala University, Rudbeck Laboratory, Uppsala, Sweden
| | - Christian Trautwein
- Division of Gastroenterology and Endocrinology, RWTH Aachen University Hospital, Aachen, Germany
| | - Ralf Hausmann
- Institute of Molecular Pharmacology, RWTH Aachen University Hospital, Aachen, Germany
| | - Susan Quaggin
- Division of Medicine-Nephrology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | | | - Wilhelm Kriz
- Department of Anatomy and Developmental Biology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Alda Tufro
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Jürgen Floege
- Division of Nephrology and Immunology, RWTH Aachen University, Aachen, Germany
| | - Marcus J Moeller
- Division of Nephrology and Immunology, RWTH Aachen University, Aachen, Germany.,Interdisciplinary Centre for Clinical Research (IZKF Aachen), RWTH Aachen University Hospital, Aachen, Germany.,Heisenberg Chair for Preventive and Translational Nephrology, Division of Nephrology, RWTH Aachen University, Aachen, Germany
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9
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Pletinck A, Van Biesen W, Dequidt C, Eloot S. Transport of neutral IgG2 versus anionic IgG4 in PD: implications on the electrokinetic model. BMC Nephrol 2018; 19:299. [PMID: 30373553 PMCID: PMC6206679 DOI: 10.1186/s12882-018-1104-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 10/17/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND It is debated whether transperitoneal membrane transport of larger (charged) molecules in peritoneal dialysis can be partially governed by the electrokinetic model. In this model, it is postulated that streaming potentials are generated across the capillary wall by forced filtration of an ionic solution, for example transcapillary ultrafiltration induced by osmotic forces as in peritoneal dialysis. We investigated the presence of streaming potentials in the process of transperitoneal transport in Peritoneal Dialysis (PD) patients by measuring ratios of dialysate concentrations of IgG2 (neutral) and IgG4 (negative), both 150kD, under different conditions of transcapillary ultrafiltration. METHODS Adult PD patients randomly got two consecutive dwells of 120 min each, with either 2 L Physioneal 1.36% or 3.86% glucose dialysis fluid (Baxter, USA) as their first dwell. A blood sample was taken at the test start, and dialysate samples were taken at 5, 15, 30, 60 and 120 min. IgG2 and IgG4 concentrations were measured (ELISA) and ratios calculated. RESULTS In 10 patients (65 ± 17 years, 20 ± 17 months on dialysis), drained volume after 120 min was different between the 1.36% (1950 [1910; 2020] mL) and 3.86% (2540 [2380; 2800] mL) glucose dwells (P = 0.007). At none of the time points and irrespective of glucose concentration, a significant difference was found between the IgG2/IgG4 ratios at any time point. CONCLUSION Our data failed to demonstrate a difference in the transport ratios of two macromolecules with same molecular weight but different charge, as would be expected by the electrokinetic model, and this despite sufficient differences in transcapillary ultrafiltration. CLINICAL TRIAL REGISTRY Belgian Registration Number B670201523397 (20/1/2015); prospective randomized trial.
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Affiliation(s)
- Anneleen Pletinck
- Nephrology Division, Ghent University Hospital, C. Heymanslaan 10, 9000, Ghent, Belgium
| | - Wim Van Biesen
- Nephrology Division, Ghent University Hospital, C. Heymanslaan 10, 9000, Ghent, Belgium.
| | - Clement Dequidt
- Nephrology Division, Ghent University Hospital, C. Heymanslaan 10, 9000, Ghent, Belgium
| | - Sunny Eloot
- Nephrology Division, Ghent University Hospital, C. Heymanslaan 10, 9000, Ghent, Belgium
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10
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Yaribeygi H, Atkin SL, Katsiki N, Sahebkar A. Narrative review of the effects of antidiabetic drugs on albuminuria. J Cell Physiol 2018; 234:5786-5797. [PMID: 30367464 DOI: 10.1002/jcp.27503] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 09/10/2018] [Indexed: 12/12/2022]
Abstract
Diabetes mellitus is the most prevalent metabolic disorder worldwide. Glycemic control is the main focus of antidiabetic therapy. However, there are data suggesting that some antidiabetic drugs may have intrinsic beneficial renal effects and protect against the development and progression of albuminuria, thus minimizing the risk of diabetic nephropathy. These pharmacological agents can suppress upstream molecular pathways involved in the pathophysiology of diabetes-induced renal dysfunction such as oxidative stress, inflammatory responses, and apoptosis. In this narrative review, the pathophysiology of albuminuria in patients with diabetic nephropathy is discussed. Furthermore, the renoprotective effects of antidiabetic drugs, focusing on albuminuria, are reviewed.
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Affiliation(s)
- Habib Yaribeygi
- Chronic Kidney Disease Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Niki Katsiki
- Second Propedeutic Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, Hippokration Hospital, Thessaloniki, Greece
| | - Amirhossein Sahebkar
- Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.,School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
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11
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Progress and controversies in unraveling the glomerular filtration mechanism. Curr Opin Nephrol Hypertens 2016; 24:208-16. [PMID: 25887902 DOI: 10.1097/mnh.0000000000000116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE OF REVIEW At first sight, the glomerular filter appears like a problem that should be easily solved. The majority of researchers view the filter like an impermeable wall perforated by specialized and size-selective pores (pore model). However, the fact that this model is in conflict with many of the experimental findings suggests that it may not yet be complete. RECENT FINDINGS In the more recent electrokinetic model, we have proposed including electrical effects (streaming potentials). The present review investigates how this can provide a relatively simple mechanistic explanation for the great majority of the so far unexplained characteristics of the filter, for example why the filter never clogs. SUMMARY Understanding how the glomerular filter functions is a prerequisite to investigate the pathogenesis of proteinuric glomerular diseases and the link between glomerular proteinuria and cardiovascular disease.
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12
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Gaiko-Shcherbak A, Fabris G, Dreissen G, Merkel R, Hoffmann B, Noetzel E. The Acinar Cage: Basement Membranes Determine Molecule Exchange and Mechanical Stability of Human Breast Cell Acini. PLoS One 2015; 10:e0145174. [PMID: 26674091 PMCID: PMC4684506 DOI: 10.1371/journal.pone.0145174] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/30/2015] [Indexed: 11/19/2022] Open
Abstract
The biophysical properties of the basement membrane that surrounds human breast glands are poorly understood, but are thought to be decisive for normal organ function and malignancy. Here, we characterize the breast gland basement membrane with a focus on molecule permeation and mechanical stability, both crucial for organ function. We used well-established and nature-mimicking MCF10A acini as 3D cell model for human breast glands, with ether low- or highly-developed basement membrane scaffolds. Semi-quantitative dextran tracer (3 to 40 kDa) experiments allowed us to investigate the basement membrane scaffold as a molecule diffusion barrier in human breast acini in vitro. We demonstrated that molecule permeation correlated positively with macromolecule size and intriguingly also with basement membrane development state, revealing a pore size of at least 9 nm. Notably, an intact collagen IV mesh proved to be essential for this permeation function. Furthermore, we performed ultra-sensitive atomic force microscopy to quantify the response of native breast acini and of decellularized basement membrane shells against mechanical indentation. We found a clear correlation between increasing acinar force resistance and basement membrane formation stage. Most important native acini with highly-developed basement membranes as well as cell-free basement membrane shells could both withstand physiologically relevant loads (≤ 20 nN) without loss of structural integrity. In contrast, low-developed basement membranes were significantly softer and more fragile. In conclusion, our study emphasizes the key role of the basement membrane as conductor of acinar molecule influx and mechanical stability of human breast glands, which are fundamental for normal organ function.
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Affiliation(s)
- Aljona Gaiko-Shcherbak
- Institute of Complex Systems ICS7: Biomechanics, Forschungszentrum Jülich, Jülich, Germany
| | - Gloria Fabris
- Institute of Complex Systems ICS7: Biomechanics, Forschungszentrum Jülich, Jülich, Germany
| | - Georg Dreissen
- Institute of Complex Systems ICS7: Biomechanics, Forschungszentrum Jülich, Jülich, Germany
| | - Rudolf Merkel
- Institute of Complex Systems ICS7: Biomechanics, Forschungszentrum Jülich, Jülich, Germany
| | - Bernd Hoffmann
- Institute of Complex Systems ICS7: Biomechanics, Forschungszentrum Jülich, Jülich, Germany
| | - Erik Noetzel
- Institute of Complex Systems ICS7: Biomechanics, Forschungszentrum Jülich, Jülich, Germany
- * E-mail:
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13
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Moeller MJ, Kuppe C. Point: Proposing the electrokinetic model. Perit Dial Int 2015; 35:5-8. [PMID: 25700457 PMCID: PMC4335921 DOI: 10.3747/pdi.2014.00189] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 07/16/2014] [Indexed: 12/13/2022] Open
Abstract
It is still not fully resolved how the glomerular filter works and why it never clogs. Several models have been proposed. In this review, we will compare the most widely used "pore model" to the more recent and refined "electrokinetic model" of glomerular filtration. The pore model assumes the existence of highly ordered regular pores, but it cannot provide a mechanistic explanation for several of the inherent characteristics of the glomerular filter. The electrokinetic model assumes that streaming potentials generate an electrical field along the filter surface which repels the negatively charged plasma proteins, preventing them from passing across the filter. The electrokinetic model can provide elegant mechanistic solutions for most of the unresolved riddles about the glomerular filter.
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Affiliation(s)
- Marcus J Moeller
- Division of Nephrology and Clinical Immunology, RWTH Aachen University Hospital, Aachen, Germany
| | - Christoph Kuppe
- Division of Nephrology and Clinical Immunology, RWTH Aachen University Hospital, Aachen, Germany
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14
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Affiliation(s)
- Bengt Rippe
- Department of Nephrology, Lund University, Lund, Sweden
| | - Carl M Öberg
- Department of Nephrology, Lund University, Lund, Sweden
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15
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Rumyantseva YV, Ryabchikova EI, Fursova AZ, Kolosova NG. Ameliorative effects of SkQ1 eye drops on cataractogenesis in senescence-accelerated OXYS rats. Graefes Arch Clin Exp Ophthalmol 2014; 253:237-48. [PMID: 25267419 DOI: 10.1007/s00417-014-2806-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 08/06/2014] [Accepted: 09/15/2014] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Antioxidant supplements have been suggested as a strategy to decrease the risk of age-related cataract, but there is no evidence that antioxidants can reduce the signs of the disease. Recently, we showed that the mitochondrial antioxidant SkQ1 can partially reverse cataract signs in senescence-accelerated OXYS rats. The aim of the present study was the histomorphological examination of the influence of SkQ1 eye drops on the cataract development in OXYS rats. METHODS OXYS rats received SkQ1 eye drops (250 nM) from 9 to 12 months of age. Ophthalmoscopic examination was carried out before and after treatment. Light and electron microscopy were used for histomorphological examination. Expression of the Cryaa and Cryab genes was determined using real-time PCR. αB-crystallin expression was detected using Western blotting. RESULTS SkQ1 completely prevented the cataract development in OXYS rats, and in some of the animals diminished the signs of the disease. Light and electron microscopy showed that SkQ1 attenuated the (typical for cataract) alterations in the lens capsule and epithelial cells, ameliorated disturbances of the hexagonal packing geometry of lens fibers, and improved ultrastructure of the epithelial cells. The levels of mRNA of α-crystallins genes which encode small heat shock proteins αA- and αB-crystallin that play a central role in maintaining lens transparency were significantly lower in the OXYS rats' lenses than in Wistar rats (control). SkQ1 normalized the level of mRNA of Cryaa, and significantly increased the level of Cryab mRNA as well as αB-crystallin protein in the lens of OXYS rats to the level of the control Wistar rats. CONCLUSION SkQ1 eye drops hold promise as a treatment of cataract.
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Affiliation(s)
- Yuliya V Rumyantseva
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630090, Acad. Lavrentjev 10, Novosibirsk, Russia,
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Moeller MJ. Streaming potentials as novel driving force for capillary permeability. Biophys J 2013; 104:1395-6. [PMID: 23561513 PMCID: PMC3617412 DOI: 10.1016/j.bpj.2013.02.045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 02/15/2013] [Indexed: 11/21/2022] Open
Affiliation(s)
- Marcus Johannes Moeller
- Department of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule University Hospital Aachen, Aachen, Germany.
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Abstract
Human kidneys produce more than 4 million litres of virtually protein-free primary urine in a lifetime. In healthy individuals, the sieving process is accomplished by the glomerular filter without the smallest sign of clogging, even in old age. How nature accomplishes this extraordinary task is a mystery, but unravelling the functioning of the glomerular filter is important. The basic principles that govern glomerular filtration are probably also true for peripheral filtering by fenestrated capillaries. In addition, understanding the sieving process is a prerequisite to understanding the pathogenesis of proteinuria (that is, the leakage of plasma proteins into the urine). Proteinuria is the hallmark of glomerular disease and a major risk factor for systemic cardiovascular complications, a fact that emphasizes the relationship between the glomerular and peripheral filtering capillaries. In this Review, we briefly summarize the major models that have been proposed for the mechanisms of glomerular filtration and discuss their strengths and limitations. A special emphasis is placed on the 'electrokinetic model' that we have proposed, a model that could potentially resolve many of the seemingly strange characteristics of the glomerular filtration barrier.
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