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Yurchenco PD, Kulczyk AW. Polymerizing laminins in development, health, and disease. J Biol Chem 2024; 300:107429. [PMID: 38825010 DOI: 10.1016/j.jbc.2024.107429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 05/12/2024] [Accepted: 05/26/2024] [Indexed: 06/04/2024] Open
Abstract
Polymerizing laminins are multi-domain basement membrane (BM) glycoproteins that self-assemble into cell-anchored planar lattices to establish the initial BM scaffold. Nidogens, collagen-IV and proteoglycans then bind to the scaffold at different domain loci to create a mature BM. The LN domains of adjacent laminins bind to each other to form a polymer node, while the LG domains attach to cytoskeletal-anchoring integrins and dystroglycan, as well as to sulfatides and heparan sulfates. The polymer node, the repeating unit of the polymer scaffold, is organized into a near-symmetrical triskelion. The structure, recently solved by cryo-electron microscopy in combination with AlphaFold2 modeling and biochemical studies, reveals how the LN surface residues interact with each other and how mutations cause failures of self-assembly in an emerging group of diseases, the LN-lamininopathies, that include LAMA2-related dystrophy and Pierson syndrome.
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Affiliation(s)
- Peter D Yurchenco
- Department of Pathology & Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA.
| | - Arkadiusz W Kulczyk
- Department of Biochemistry and Microbiology, Institute for Quantitative Biomedicine, Rutgers University, Piscataway, New Jersey, USA
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2
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Chen D, Zhou X, Gan C, Yang Q, Chen W, Feng X, Zhang T, Zhang L, Dai L, Chen Y, Yang H, Wang M, Jiang W, Li Q. Characterization of glomerular basement membrane components within pediatric glomerular diseases. Clin Kidney J 2024; 17:sfae037. [PMID: 38455522 PMCID: PMC10919337 DOI: 10.1093/ckj/sfae037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Indexed: 03/09/2024] Open
Abstract
Background Disruptions in gene expression associated with the glomerular basement membrane (GBM) could precipitate glomerular dysfunction. Nevertheless, a comprehensive understanding of the characterization of GBM components within pediatric glomerular diseases and their potential association with glomerular function necessitates further systematic investigation. Methods We conducted a systematic analysis focusing on the pathological transformations and molecular attributes of key constituents within the GBM, specifically Collagen IV α3α4α5, Laminin α5β2γ1, and Integrin α3β1, across prevalent pediatric glomerular diseases. Results We observed upregulation of linear expression levels of COL4A3/4/5 and Laminin 5α proteins, along with a partial reduction in the linear structural expression of Podocin in idiopathic nephrotic syndrome (INS), encompassing minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS), but showing a reduction in IgA nephropathy (IgAN), IgA vasculitis nephritis (IgAVN) and lupus nephritis (LN). Furthermore, our study revealed reductions in Laminin β2γ1 and Integrin α3β1 in both primary and secondary childhood glomerular diseases. Conclusion In INS, notably MCD and FSGS, there is a notable increase in the linear expression levels of COL4A3/4/5 and Laminin 5α proteins. In contrast, in IgAN, IgAVN, and LN, there is a consistent reduction in the expression of these markers. Furthermore, the persistent reduction of Laminin β2γ1 and Integrin α3β1 in both primary and secondary childhood glomerular diseases suggests a shared characteristic of structural alterations within the GBM across these conditions.
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Affiliation(s)
- Dan Chen
- Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, P.R. China
| | - Xindi Zhou
- Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, P.R. China
| | - Chun Gan
- Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, P.R. China
| | - Qing Yang
- Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, P.R. China
| | - Wanbing Chen
- Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, P.R. China
| | - Xiaoqian Feng
- Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, P.R. China
- Chongqing University Three Gorges Hospital, School of Medicine of Chongqing University, Chongqing, P.R. China
| | - Tao Zhang
- Pediatric Renal Immunology Specialist Section, The Affiliated Hospital of Guizhou Medical University, Guizhou Provincial Children's Medical Center, Guiyang, Guizhou, P.R. China
| | - Li Zhang
- Pediatric Renal Immunology Specialist Section, The Affiliated Hospital of Guizhou Medical University, Guizhou Provincial Children's Medical Center, Guiyang, Guizhou, P.R. China
| | - Lujun Dai
- Department of Pathology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, P.R. China
| | - Yaxi Chen
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, P.R. China
| | - Haiping Yang
- Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, P.R. China
| | - Mo Wang
- Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, P.R. China
| | - Wei Jiang
- Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, P.R. China
| | - Qiu Li
- Department of Nephrology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatric Metabolism and Inflammatory Diseases, Chongqing, P.R. China
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Leventoğlu E, Dönmez E, Uzun Kenan B, Yazıcıoğlu B, Büyükkaragöz B, Fidan K, Bakkaloğlu SA, Söylemezoğlu O. LAMB2 gene: broad clinical spectrum in Pierson syndrome. CEN Case Rep 2023:10.1007/s13730-023-00838-y. [PMID: 38038886 DOI: 10.1007/s13730-023-00838-y] [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: 08/12/2023] [Accepted: 11/06/2023] [Indexed: 12/02/2023] Open
Abstract
Pierson syndrome (PS) is a rare autosomal recessive disease, characterized by congenital nephrotic syndrome (CNS), and ocular and neurologic abnormalities. In affected cases, there is abnormal b-2 laminin which is compound of the several basement membranes caused by inherited mutations in the LAMB2 gene. Although patients have mutations in the same gene, the phenotype is highly variable. In this case series, the relationship between genotype and phenotype is emphasized, and information about the clinical follow-up of the patients is presented. Hereby, we report four pediatric cases with PS as a result of mutation in the LAMB2 gene. Clinical spectrum of LAMB2-associated disorders varies from mild-to-severe ocular, kidney, and neurologic involvement. Since genotype-phenotype correlation in PS has not been clearly demonstrated, we recommend that all patients with ophthalmic anomalies and glomerular proteinuria should be tested for LAMB2 mutations.
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Affiliation(s)
- Emre Leventoğlu
- Department of Pediatric Nephrology, Faculty of Medicine, Gazi University, Ankara, Turkey.
| | - Emine Dönmez
- Department of Pediatrics, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Bahriye Uzun Kenan
- Department of Pediatric Nephrology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Burcu Yazıcıoğlu
- Department of Pediatric Nephrology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Bahar Büyükkaragöz
- Department of Pediatric Nephrology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Kibriya Fidan
- Department of Pediatric Nephrology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Sevcan A Bakkaloğlu
- Department of Pediatric Nephrology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Oğuz Söylemezoğlu
- Department of Pediatric Nephrology, Faculty of Medicine, Gazi University, Ankara, Turkey
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4
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Boyer O, Mollet G, Dorval G. [Neurological disorders and hereditary podocytopathies: Some fascinating pathophysiological overlaps]. Med Sci (Paris) 2023; 39:246-252. [PMID: 36943121 DOI: 10.1051/medsci/2023029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Abstract
Genetic studies of hereditary steroid resistant nephrotic syndrome (SRNS) have identified more than 60 genes involved in the development of single-gene, isolated or syndromic forms of hereditary podocytoapthies. Sometimes, syndromic SRNS is associated with neurological disorders. Over the past decades, various studies have established links between the podocyte, an epithelial glomerular cell involved in the renal filtration barrier, and neuronal cells, both morphologically (slit diaphragm and synapse) and functionally (signaling platforms). Variants of genes encoding proteins expressed in different compartments of the podocyte and neurons are responsible for phenotypes associating renal lesions with proteinuria to central and/or peripheral neurological disorders. In this review, we aim to focus on genetic syndromes associating proteinuria and neurological disease and to present the latest advances in the description of these neuro-renal disorders.
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Affiliation(s)
- Olivia Boyer
- Service de néphrologie pédiatrique, AP-HP, Centre de référence de maladies rénales rares de l'enfant et de l'adulte (MARHEA), hôpital Necker - Enfants Malades, Paris, France - Université Paris Cité, institut Imagine, laboratoire des maladies rénales héréditaires, Inserm UMR1163, Paris, France
| | - Géraldine Mollet
- Université Paris Cité, institut Imagine, laboratoire des maladies rénales héréditaires, Inserm UMR1163, Paris, France
| | - Guillaume Dorval
- Université Paris Cité, institut Imagine, laboratoire des maladies rénales héréditaires, Inserm UMR1163, Paris, France - Service de génétique moléculaire, AP-HP, hôpital Necker-Enfants Malades, Paris, France
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5
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Abdollahzadeh F, Khoshdel-Rad N, Moghadasali R. Kidney development and function: ECM cannot be ignored. Differentiation 2022; 124:28-42. [DOI: 10.1016/j.diff.2022.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 01/29/2022] [Accepted: 02/04/2022] [Indexed: 11/03/2022]
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6
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Tajima K, Yagi H, Morisaku T, Nishi K, Kushige H, Kojima H, Higashi H, Kuroda K, Kitago M, Adachi S, Natsume T, Nishimura K, Oya M, Kitagawa Y. An organ-derived extracellular matrix triggers in situ kidney regeneration in a preclinical model. NPJ Regen Med 2022; 7:18. [PMID: 35228532 PMCID: PMC8885654 DOI: 10.1038/s41536-022-00213-y] [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: 09/29/2021] [Accepted: 02/07/2022] [Indexed: 01/20/2023] Open
Abstract
It has not been considered that nephrons regenerate in adult mammals. We present that an organ-derived extracellular matrix in situ induces nephron regeneration in a preclinical model. A porcine kidney-derived extracellular matrix was sutured onto the surface of partial nephrectomy (PN)-treated kidney. Twenty-eight days after implantation, glomeruli, vessels, and renal tubules, characteristic of nephrons, were histologically observed within the matrix. No fibrillogenesis was observed in the matrix nor the matrix-sutured kidney, although this occurred in a PN kidney without the matrix, indicating the structures were newly induced by the matrix. The expression of renal progenitor markers, including Sall1, Six2, and WT-1, within the matrix supported the induction of nephron regeneration by the matrix. Furthermore, active blood flow was observed inside the matrix using computed tomography. The matrix provides structural and functional foundations for the development of cell-free scaffolds with a remarkably low risk of immune rejection and cancerization.
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7
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Boyer O, Mollet G, Dorval G. Neurological involvement in monogenic podocytopathies. Pediatr Nephrol 2021; 36:3571-3583. [PMID: 33791874 DOI: 10.1007/s00467-020-04903-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/27/2020] [Accepted: 12/11/2020] [Indexed: 01/22/2023]
Abstract
Genetic studies of hereditary nephrotic syndrome (NS) have identified more than 50 genes that, if mutated, are responsible for monogenic forms of steroid-resistant NS (SRNS), either isolated or syndromic. Most of these genes encode proteins expressed in the podocyte with various functions such as transcription factors, mitochondrial proteins, or enzymes, but mainly structural proteins of the slit diaphragm (SD) as well as cytoskeletal binding and regulator proteins. Syndromic NS is sometimes associated with neurological features. Over recent decades, various studies have established links between the physiology of podocytes and neurons, both morphologically (slit diaphragm and synapse) and functionally (signaling platforms). Variants in genes expressed in different compartments of the podocyte and neurons are responsible for phenotypes associating kidney lesions with proteinuria (mainly Focal and Segmental Glomerulosclerosis (FSGS) or Diffuse Mesangial Sclerosis (DMS)) and central and/or peripheral neurological disorders. The Galloway-Mowat syndrome (GAMOS, OMIM#251300) associates neurological defects, microcephaly, and proteinuria and is caused by variants in genes encoding proteins of various functions (microtubule cytoskeleton regulation (WDR73), regulation of protein synthesis via transfer RNAs (KEOPS and WDR4 complexes)). Pierson syndrome (OMIM#609049) associating congenital nephrotic syndrome and central neurological and ophthalmological anomalies is secondary to variants in LAMB2, involved in glomerular and ocular basement membranes. Finally, Charcot-Marie-Tooth-FSGS (OMIM#614455) combines peripheral sensory-motor neuropathy and proteinuria and arises from INF2 variants, resulting in cytoskeletal polymerization defects. This review focuses on genetic syndromes associating nephrotic range proteinuria and neurological involvement and provides the latest advances in the description of these neuro-renal disorders.
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Affiliation(s)
- Olivia Boyer
- Service de Néphrologie Pédiatrique, AP-HP, Centre de Référence de maladies rénales rares de l'enfant et de l'adulte (MARHEA), Hôpital Necker - Enfants Malades, 149 Rue de Sèvres, 75015, Paris, France.
- Institut Imagine, Laboratoire des maladies rénales héréditaires, INSERM UMR 1163, Université de Paris, Paris, France.
| | - Géraldine Mollet
- Institut Imagine, Laboratoire des maladies rénales héréditaires, INSERM UMR 1163, Université de Paris, Paris, France
| | - Guillaume Dorval
- Institut Imagine, Laboratoire des maladies rénales héréditaires, INSERM UMR 1163, Université de Paris, Paris, France
- Service de Génétique Moléculaire, AP-HP, Hôpital Necker-Enfants Malades, Paris, France
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8
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Tonti OR, Larson H, Lipp SN, Luetkemeyer CM, Makam M, Vargas D, Wilcox SM, Calve S. Tissue-specific parameters for the design of ECM-mimetic biomaterials. Acta Biomater 2021; 132:83-102. [PMID: 33878474 PMCID: PMC8434955 DOI: 10.1016/j.actbio.2021.04.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 03/18/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023]
Abstract
The extracellular matrix (ECM) is a complex network of biomolecules that mechanically and biochemically directs cell behavior and is crucial for maintaining tissue function and health. The heterogeneous organization and composition of the ECM varies within and between tissue types, directing mechanics, aiding in cell-cell communication, and facilitating tissue assembly and reassembly during development, injury and disease. As technologies like 3D printing rapidly advance, researchers are better able to recapitulate in vivo tissue properties in vitro; however, tissue-specific variations in ECM composition and organization are not given enough consideration. This is in part due to a lack of information regarding how the ECM of many tissues varies in both homeostatic and diseased states. To address this gap, we describe the components and organization of the ECM, and provide examples for different tissues at various states of disease. While many aspects of ECM biology remain unknown, our goal is to highlight the complexity of various tissues and inspire engineers to incorporate unique components of the native ECM into in vitro platform design and fabrication. Ultimately, we anticipate that the use of biomaterials that incorporate key tissue-specific ECM will lead to in vitro models that better emulate human pathologies. STATEMENT OF SIGNIFICANCE: Biomaterial development primarily emphasizes the engineering of new materials and therapies at the expense of identifying key parameters of the tissue that is being emulated. This can be partially attributed to the difficulty in defining the 3D composition, organization, and mechanics of the ECM within different tissues and how these material properties vary as a function of homeostasis and disease. In this review, we highlight a range of tissues throughout the body and describe how ECM content, cell diversity, and mechanical properties change in diseased tissues and influence cellular behavior. Accurately mimicking the tissue of interest in vitro by using ECM specific to the appropriate state of homeostasis or pathology in vivo will yield results more translatable to humans.
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Affiliation(s)
- Olivia R Tonti
- Paul M. Rady Department of Mechanical Engineering, University of Colorado - Boulder, 1111 Engineering Center, 427 UCB, Boulder, CO 80309, United States
| | - Hannah Larson
- Paul M. Rady Department of Mechanical Engineering, University of Colorado - Boulder, 1111 Engineering Center, 427 UCB, Boulder, CO 80309, United States
| | - Sarah N Lipp
- Paul M. Rady Department of Mechanical Engineering, University of Colorado - Boulder, 1111 Engineering Center, 427 UCB, Boulder, CO 80309, United States
| | - Callan M Luetkemeyer
- Paul M. Rady Department of Mechanical Engineering, University of Colorado - Boulder, 1111 Engineering Center, 427 UCB, Boulder, CO 80309, United States
| | - Megan Makam
- Paul M. Rady Department of Mechanical Engineering, University of Colorado - Boulder, 1111 Engineering Center, 427 UCB, Boulder, CO 80309, United States
| | - Diego Vargas
- Paul M. Rady Department of Mechanical Engineering, University of Colorado - Boulder, 1111 Engineering Center, 427 UCB, Boulder, CO 80309, United States
| | - Sean M Wilcox
- Paul M. Rady Department of Mechanical Engineering, University of Colorado - Boulder, 1111 Engineering Center, 427 UCB, Boulder, CO 80309, United States
| | - Sarah Calve
- Paul M. Rady Department of Mechanical Engineering, University of Colorado - Boulder, 1111 Engineering Center, 427 UCB, Boulder, CO 80309, United States.
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9
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Kikkawa Y, Hashimoto T, Takizawa K, Urae S, Masuda H, Matsunuma M, Yamada Y, Hamada K, Nomizu M, Liapis H, Hisano M, Akioka Y, Miura K, Hattori M, Miner JH, Harita Y. Laminin β2 variants associated with isolated nephropathy that impact matrix regulation. JCI Insight 2021; 6:145908. [PMID: 33749661 PMCID: PMC8026196 DOI: 10.1172/jci.insight.145908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/10/2021] [Indexed: 11/17/2022] Open
Abstract
Mutations in LAMB2, encoding laminin β2, cause Pierson syndrome and occasionally milder nephropathy without extrarenal abnormalities. The most deleterious missense mutations that have been identified affect primarily the N-terminus of laminin β2. On the other hand, those associated with isolated nephropathy are distributed across the entire molecule, and variants in the β2 LEa-LF-LEb domains are exclusively found in cases with isolated nephropathy. Here we report the clinical features of mild isolated nephropathy associated with 3 LAMB2 variants in the LEa-LF-LEb domains (p.R469Q, p.G699R, and p.R1078C) and their biochemical characterization. Although Pierson syndrome missense mutations often inhibit laminin β2 secretion, the 3 recombinant variants were secreted as efficiently as WT. However, the β2 variants lost pH dependency for heparin binding, resulting in aberrant binding under physiologic conditions. This suggests that the binding of laminin β2 to negatively charged molecules is involved in glomerular basement membrane (GBM) permselectivity. Moreover, the excessive binding of the β2 variants to other laminins appears to lead to their increased deposition in the GBM. Laminin β2 also serves as a potentially novel cell-adhesive ligand for integrin α4β1. Our findings define biochemical functions of laminin β2 variants influencing glomerular filtration that may underlie the pathogenesis of isolated nephropathy caused by LAMB2 abnormalities.
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Affiliation(s)
- Yamato Kikkawa
- Department of Clinical Biochemistry, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Taeko Hashimoto
- Department of Pediatrics, Yamagata University School of Medicine, Yamagata, Japan.,Department of Pediatric Nephrology, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan
| | - Keiichi Takizawa
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Seiya Urae
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Haruka Masuda
- Department of Clinical Biochemistry, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Masumi Matsunuma
- Department of Clinical Biochemistry, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Yuji Yamada
- Department of Clinical Biochemistry, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Keisuke Hamada
- Department of Clinical Biochemistry, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Motoyoshi Nomizu
- Department of Clinical Biochemistry, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Helen Liapis
- Department of Pathology and Immunology and Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Masataka Hisano
- Department of Nephrology, Chiba Children's Hospital, Chiba, Japan
| | - Yuko Akioka
- Department of Pediatric Nephrology, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan.,Department of Pediatrics, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Kenichiro Miura
- Department of Pediatric Nephrology, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan
| | - Motoshi Hattori
- Department of Pediatric Nephrology, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, and Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Yutaka Harita
- Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Abstract
The glomerular basement membrane (GBM) is a key component of the glomerular capillary wall and is essential for kidney filtration. The major components of the GBM include laminins, type IV collagen, nidogens and heparan sulfate proteoglycans. In addition, the GBM harbours a number of other structural and regulatory components and provides a reservoir for growth factors. New technologies have improved our ability to study the composition and assembly of basement membranes. We now know that the GBM is a complex macromolecular structure that undergoes key transitions during glomerular development. Defects in GBM components are associated with a range of hereditary human diseases such as Alport syndrome, which is caused by defects in the genes COL4A3, COL4A4 and COL4A5, and Pierson syndrome, which is caused by variants in LAMB2. In addition, the GBM is affected by acquired autoimmune disorders and metabolic diseases such as diabetes mellitus. Current treatments for diseases associated with GBM involvement aim to reduce intraglomerular pressure and to treat the underlying cause where possible. As our understanding about the maintenance and turnover of the GBM improves, therapies to replace GBM components or to stimulate GBM repair could translate into new therapies for patients with GBM-associated disease.
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11
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Funk SD, Bayer RH, McKee KK, Okada K, Nishimune H, Yurchenco PD, Miner JH. A deletion in the N-terminal polymerizing domain of laminin β2 is a new mouse model of chronic nephrotic syndrome. Kidney Int 2020; 98:133-146. [PMID: 32456966 DOI: 10.1016/j.kint.2020.01.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 01/14/2020] [Accepted: 01/21/2020] [Indexed: 10/25/2022]
Abstract
The importance of the glomerular basement membrane (GBM) in glomerular filtration is underscored by the manifestations of Alport and Pierson syndromes, caused by defects in type IV collagen α3α4α5 and the laminin β2 chain, respectively. Lamb2 null mice, which model the most severe form of Pierson syndrome, exhibit proteinuria prior to podocyte foot process effacement and are therefore useful for studying GBM permselectivity. We hypothesize that some LAMB2 missense mutations that cause mild forms of Pierson syndrome induce GBM destabilization with delayed effects on podocytes. While generating a CRISPR/Cas9-mediated analogue of a human LAMB2 missense mutation in mice, we identified a 44-amino acid deletion (LAMB2-Del44) within the laminin N-terminal domain, a domain mediating laminin polymerization. Laminin heterotrimers containing LAMB2-Del44 exhibited a 90% reduction in polymerization in vitro that was partially rescued by type IV collagen and nidogen. Del44 mice showed albuminuria at 1.8-6.0 g/g creatinine (ACR) at one to two months, plateauing at an average 200 g/g ACR at 3.7 months, when GBM thickening and hallmarks of nephrotic syndrome were first observed. Despite the massive albuminuria, some Del44 mice survived for up to 15 months. Blood urea nitrogen was modestly elevated at seven-nine months. Eight to nine-month-old Del44 mice exhibited glomerulosclerosis and interstitial fibrosis. Similar to Lamb2-/- mice, proteinuria preceded foot process effacement. Foot processes were widened but not effaced at one-two months despite the high ACRs. At three months some individual foot processes were still observed amid widespread effacement. Thus, our chronic model of nephrotic syndrome may prove useful to study filtration mechanisms, long-term proteinuria with preserved kidney function, and to test therapeutics.
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Affiliation(s)
- Steven D Funk
- Department of Internal Medicine, Division of Nephrology, Washington University, St. Louis, Missouri, USA
| | - Raymond H Bayer
- Department of Internal Medicine, Division of Nephrology, Washington University, St. Louis, Missouri, USA
| | - Karen K McKee
- Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Kazushi Okada
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, USA
| | - Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, USA
| | - Peter D Yurchenco
- Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Jeffrey H Miner
- Department of Internal Medicine, Division of Nephrology, Washington University, St. Louis, Missouri, USA.
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Kim K, Araujo P, Hebbar N, Zhou Z, Zheng X, Zheng F, Rangnekar VM, Zhan CG. Development of a novel prostate apoptosis response-4 (Par-4) protein entity with an extended duration of action for therapeutic treatment of cancer. Protein Eng Des Sel 2019; 32:159-166. [PMID: 31711233 DOI: 10.1093/protein/gzz034] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 07/28/2019] [Accepted: 07/31/2019] [Indexed: 01/20/2023] Open
Abstract
Prostate apoptosis response-4 (Par-4) is a tumor suppressor which protects against neoplastic transformation. Remarkably, Par-4 is capable of inducing apoptosis selectively in cancer cells without affecting the normal cells. In this study, we found that recombinant Par-4 protein had limited serum persistence in mice that may diminish its anti-tumor activity in vivo. To improve the in vivo performance of the short-lived Par-4 protein, we aimed to develop a novel, long-lasting form of Par-4 with extended sequence, denoted as Par-4Ex, without affecting the desirable molecular function of the natural Par-4. We demonstrate that the Par-4Ex protein entity, produced by using the Escherichia coli expression system suitable for large-scale production, fully retains the desirable pro-apoptotic activity of Par-4 protein, but with ~7-fold improved biological half-life. Further in vivo tests confirmed that, due to the prolonged biological half-life, the Par-4Ex protein is indeed more potent in suppressing metastatic tumor growth in mice.
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Affiliation(s)
- Kyungbo Kim
- Molecular Modeling and Biopharmaceutical Center, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
| | - Pereira Araujo
- Graduate Center for Toxicology and Cancer Biology, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA
| | - Nikhil Hebbar
- Graduate Center for Toxicology and Cancer Biology, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA
| | - Ziyuan Zhou
- Molecular Modeling and Biopharmaceutical Center, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
| | - Xirong Zheng
- Molecular Modeling and Biopharmaceutical Center, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
| | - Fang Zheng
- Molecular Modeling and Biopharmaceutical Center, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
| | - Vivek M Rangnekar
- Graduate Center for Toxicology and Cancer Biology, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA.,Department of Radiation Medicine, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA.,Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA.,Lucille Parker Markey Cancer Center, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical Center, University of Kentucky, 789 South Limestone Street, Lexington, KY 40356, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA
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13
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Zhu HT, Maimaiti M, Cao C, Luo YF, Julaiti D, Liang L, Abudureheman A. A Novel Homozygous Truncating Mutation in LAMB2 Gene in a Chinese Uyghur Patient With Severe Phenotype Pierson Syndrome. Front Med (Lausanne) 2019; 6:12. [PMID: 30778388 PMCID: PMC6369156 DOI: 10.3389/fmed.2019.00012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 01/16/2019] [Indexed: 11/13/2022] Open
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14
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Korolj A, Laschinger C, James C, Hu E, Velikonja C, Smith N, Gu I, Ahadian S, Willette R, Radisic M, Zhang B. Curvature facilitates podocyte culture in a biomimetic platform. LAB ON A CHIP 2018; 18:3112-3128. [PMID: 30264844 DOI: 10.1039/c8lc00495a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Most kidney diseases begin with abnormalities in glomerular podocytes, motivating the need for podocyte models to study pathophysiological mechanisms and new treatment options. However, podocytes cultured in vitro face a limited ability to maintain appreciable extents of differentiation hallmarks, raising concerns over the relevance of study results. Many key properties such as nephrin expression and morphology reach plateaus that are far from the in vivo levels. Here, we demonstrate that a biomimetic topography, consisting of microhemispheres arrayed over the cell culture substrate, promotes podocyte differentiation in vitro. We define new methods for fabricating microscale curvature on various substrates, including a thin porous membrane. By growing podocytes on our topographic substrates, we found that these biophysical cues augmented nephrin gene expression, supported full-size nephrin protein expression, encouraged structural arrangement of F-actin and nephrin within the cell, and promoted process formation and even interdigitation compared to the flat substrates. Furthermore, the topography facilitated nephrin localization on curved structures while nuclei lay in the valleys between them. The improved differentiation was also evidenced by tracking barrier function to albumin over time using our custom topomembranes. Overall, our work presents accessible methods for incorporating microcurvature on various common substrates, and demonstrates the importance of biophysical stimulation in supporting higher-fidelity podocyte cultivation in vitro.
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Affiliation(s)
- Anastasia Korolj
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Canada.
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15
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Funk SD, Lin MH, Miner JH. Alport syndrome and Pierson syndrome: Diseases of the glomerular basement membrane. Matrix Biol 2018; 71-72:250-261. [PMID: 29673759 PMCID: PMC6146048 DOI: 10.1016/j.matbio.2018.04.008] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 04/13/2018] [Accepted: 04/13/2018] [Indexed: 12/17/2022]
Abstract
The glomerular basement membrane (GBM) is an important component of the kidney's glomerular filtration barrier. Like all basement membranes, the GBM contains type IV collagen, laminin, nidogen, and heparan sulfate proteoglycan. It is flanked by the podocytes and glomerular endothelial cells that both synthesize it and adhere to it. Mutations that affect the GBM's collagen α3α4α5(IV) components cause Alport syndrome (kidney disease with variable ear and eye defects) and its variants, including thin basement membrane nephropathy. Mutations in LAMB2 that impact the synthesis or function of laminin α5β2γ1 (LM-521) cause Pierson syndrome (congenital nephrotic syndrome with eye and neurological defects) and its less severe variants, including isolated congenital nephrotic syndrome. The very different types of kidney diseases that result from mutations in collagen IV vs. laminin are likely due to very different pathogenic mechanisms. A better understanding of these mechanisms should lead to targeted therapeutic approaches that can help people with these rare but important diseases.
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Affiliation(s)
- Steven D Funk
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Meei-Hua Lin
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
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16
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Nyström A, Bruckner-Tuderman L. Matrix molecules and skin biology. Semin Cell Dev Biol 2018; 89:136-146. [PMID: 30076963 DOI: 10.1016/j.semcdb.2018.07.025] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 06/26/2018] [Accepted: 07/31/2018] [Indexed: 01/02/2023]
Abstract
An extracellular matrix (ECM) is a prerequisite for multicellular life. It is adapted to tissues and constantly undergoes changes to preserve microenvironmental homeostasis. The ECM acts as a structural scaffold that establishes tissue architecture and provides tensile strength. It has cell-instructive functions by serving as a reservoir and presenter of soluble agents, being directly signaling, integrating transmission of mechanical and biological cues, or serving as a co-factor potentiating signaling. The skin contains a highly developed, mechanically tough, but yet flexible ECM. The tissue-specific features of this ECM are largely attributed by minor ECM components. A large number of genetic and acquired ECM diseases with skin manifestations, provide an illustrative testament to the importance of correct assembly of the ECM for dermal homeostasis. Here, we will present the composition and features of the skin ECM during homeostasis and regeneration. We will discuss genetic and acquired ECM diseases affecting skin, and provide a short outlook to therapeutic strategies for them.
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Affiliation(s)
- Alexander Nyström
- Department of Dermatology, Medical Faculty, Medical Center - University of Freiburg, Freiburg, Germany.
| | - Leena Bruckner-Tuderman
- Department of Dermatology, Medical Faculty, Medical Center - University of Freiburg, Freiburg, Germany
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17
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Affiliation(s)
- Alda Tufro
- Departments of Pediatrics and Cell and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut
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18
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Lin MH, Miller JB, Kikkawa Y, Suleiman HY, Tryggvason K, Hodges BL, Miner JH. Laminin-521 Protein Therapy for Glomerular Basement Membrane and Podocyte Abnormalities in a Model of Pierson Syndrome. J Am Soc Nephrol 2018; 29:1426-1436. [PMID: 29472414 PMCID: PMC5967757 DOI: 10.1681/asn.2017060690] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 01/14/2018] [Indexed: 12/22/2022] Open
Abstract
Background Laminin α5β2γ1 (LM-521) is a major component of the GBM. Mutations in LAMB2 that prevent LM-521 synthesis and/or secretion cause Pierson syndrome, a rare congenital nephrotic syndrome with diffuse mesangial sclerosis and ocular and neurologic defects. Because the GBM is uniquely accessible to plasma, which permeates endothelial cell fenestrae, we hypothesized that intravenous delivery of LM-521 could replace the missing LM-521 in the GBM of Lamb2 mutant mice and restore glomerular permselectivity.Methods We injected human LM-521 (hLM-521), a macromolecule of approximately 800 kD, into the retro-orbital sinus of Lamb2-/- pups daily. Deposition of hLM-521 into the GBM was investigated by fluorescence microscopy. We assayed the effects of hLM-521 on glomerular permselectivity by urinalysis and the effects on podocytes by desmin immunostaining and ultrastructural analysis of podocyte architecture.Results Injected hLM-521 rapidly and stably accumulated in the GBM of all glomeruli. Super-resolution imaging showed that hLM-521 accumulated in the correct orientation in the GBM, primarily on the endothelial aspect. Treatment with hLM-521 greatly reduced the expression of the podocyte injury marker desmin and attenuated the foot process effacement observed in untreated pups. Moreover, treatment with hLM-521 delayed the onset of proteinuria but did not prevent nephrotic syndrome, perhaps due to its absence from the podocyte aspect of the GBM.Conclusions These studies show that GBM composition and function can be altered in vivovia vascular delivery of even very large proteins, which may advance therapeutic options for patients with abnormal GBM composition, whether genetic or acquired.
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Affiliation(s)
- Meei-Hua Lin
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Joseph B Miller
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Yamato Kikkawa
- Department of Clinical Biochemistry, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Hani Y Suleiman
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Karl Tryggvason
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden; and
| | | | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri;
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19
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Yang JW, Dettmar AK, Kronbichler A, Gee HY, Saleem M, Kim SH, Shin JI. Recent advances of animal model of focal segmental glomerulosclerosis. Clin Exp Nephrol 2018; 22:752-763. [PMID: 29556761 DOI: 10.1007/s10157-018-1552-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 02/26/2018] [Indexed: 12/15/2022]
Abstract
In the last decade, great advances have been made in understanding the genetic basis for focal segmental glomerulosclerosis (FSGS). Animal models using specific gene disruption of the slit diaphragm and cytoskeleton of the foot process mirror the etiology of the human disease. Many animal models have been developed to understand the complex pathophysiology of FSGS. Therefore, we need to know the usefulness and exact methodology of creating animal models. Here, we review classic animal models and newly developed genetic animal models. Classic animal models of FSGS involve direct podocyte injury and indirect podocyte injury due to adaptive responses. However, the phenotype depends on the animal background. Renal ablation and direct podocyte toxin (PAN, adriamycin) models are leading animal models for FSGS, which have some limitations depending on mice background. A second group of animal models were developed using combinations of genetic mutation and toxin, such as NEP25, diphtheria toxin, and Thy1.1 models, which specifically injure podocytes. A third group of animal models involves genetic engineering techniques targeting podocyte expression molecules, such as podocin, CD2-associated protein, and TRPC6 channels. More detailed information about podocytopathy and FSGS can be expected in the coming decade. Different animal models should be used to study FSGS depending on the specific aim and sometimes should be used in combination.
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Affiliation(s)
- Jae Won Yang
- Department of Nephrology, Yonsei University Wonju College of Medicine, Wonju, Gangwon, Republic of Korea
| | - Anne Katrin Dettmar
- Pediatric Nephrology, Department of Pediatrics, Medical University Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas Kronbichler
- Department of Internal Medicine IV (Nephrology and Hypertension), Universitätskliniken Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria
| | - Heon Yung Gee
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Moin Saleem
- Paediatric Renal Medicine, University of Bristol, Bristol, UK.,Children's Renal Unit, Bristol Royal Hospital for Children, Bristol, UK
| | - Seong Heon Kim
- Department of Pediatrics, Pusan National University Children's Hospital, Yangsan, Republic of Korea. .,Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea.
| | - Jae Il Shin
- Department of Pediatrics, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea.
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20
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Abstract
The glomerular basement membrane (GBM) is a specialized structure with a significant role in maintaining the glomerular filtration barrier. This GBM is formed from the fusion of two basement membranes during development and its function in the filtration barrier is achieved by key extracellular matrix components including type IV collagen, laminins, nidogens, and heparan sulfate proteoglycans. The characteristics of specific matrix isoforms such as laminin-521 (α5β2γ1) and the α3α4α5 chain of type IV collagen are essential for the formation of a mature GBM and the restricted tissue distribution of these isoforms makes the GBM a unique structure. Detailed investigation of the GBM has been driven by the identification of inherited abnormalities in matrix proteins and the need to understand pathogenic mechanisms causing severe glomerular disease. A well-described hereditary GBM disease is Alport syndrome, associated with a progressive glomerular disease, hearing loss, and lens defects due to mutations in the genes COL4A3, COL4A4, or COL4A5. Other proteins associated with inherited diseases of the GBM include laminin β2 in Pierson syndrome and LMX1B in nail patella syndrome. The knowledge of these genetic mutations associated with GBM defects has enhanced our understanding of cell-matrix signaling pathways affected in glomerular disease. This review will address current knowledge of GBM-associated abnormalities and related signaling pathways, as well as discussing the advances toward disease-targeted therapies for patients with glomerular disease.
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Affiliation(s)
- Christine Chew
- Faculty of Biology Medicine and Health, Wellcome Trust Centre for Cell-Matrix Research, Division of Cell Matrix Biology, School of Biological Sciences, University of Manchester, Manchester, United Kingdom
| | - Rachel Lennon
- Faculty of Biology Medicine and Health, Wellcome Trust Centre for Cell-Matrix Research, Division of Cell Matrix Biology, School of Biological Sciences, University of Manchester, Manchester, United Kingdom.,Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
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21
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Funk SD, Bayer RH, Malone AF, McKee KK, Yurchenco PD, Miner JH. Pathogenicity of a Human Laminin β2 Mutation Revealed in Models of Alport Syndrome. J Am Soc Nephrol 2017; 29:949-960. [PMID: 29263159 DOI: 10.1681/asn.2017090997] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 11/19/2017] [Indexed: 01/15/2023] Open
Abstract
Pierson syndrome is a congenital nephrotic syndrome with eye and neurologic defects caused by mutations in laminin β2 (LAMB2), a major component of the glomerular basement membrane (GBM). Pathogenic missense mutations in human LAMB2 cluster in or near the laminin amino-terminal (LN) domain, a domain required for extracellular polymerization of laminin trimers and basement membrane scaffolding. Here, we investigated an LN domain missense mutation, LAMB2-S80R, which was discovered in a patient with Pierson syndrome and unusually late onset of proteinuria. Biochemical data indicated that this mutation impairs laminin polymerization, which we hypothesized to be the cause of the patient's nephrotic syndrome. Testing this hypothesis in genetically altered mice showed that the corresponding amino acid change (LAMB2-S83R) alone is not pathogenic. However, expression of LAMB2-S83R significantly increased the rate of progression to kidney failure in a Col4a3-/- mouse model of autosomal recessive Alport syndrome and increased proteinuria in Col4a5+/- females that exhibit a mild form of X-linked Alport syndrome due to mosaic deposition of collagen α3α4α5(IV) in the GBM. Collectively, these data show the pathogenicity of LAMB2-S80R and provide the first evidence of genetic modification of Alport phenotypes by variation in another GBM component. This finding could help explain the wide range of Alport syndrome onset and severity observed in patients with Alport syndrome, even for family members who share the same COL4 mutation. Our results also show the complexities of using model organisms to investigate genetic variants suspected of being pathogenic in humans.
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Affiliation(s)
- Steven D Funk
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri and
| | - Raymond H Bayer
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri and
| | - Andrew F Malone
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri and
| | - Karen K McKee
- Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey
| | - Peter D Yurchenco
- Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri and
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22
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Tabatabaeifar M, Wlodkowski T, Simic I, Denc H, Mollet G, Weber S, Moyers JJ, Brühl B, Randles MJ, Lennon R, Antignac C, Schaefer F. An inducible mouse model of podocin-mutation-related nephrotic syndrome. PLoS One 2017; 12:e0186574. [PMID: 29049388 PMCID: PMC5648285 DOI: 10.1371/journal.pone.0186574] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/10/2017] [Indexed: 12/03/2022] Open
Abstract
Mutations in the NPHS2 gene, encoding podocin, cause hereditary nephrotic syndrome. The most common podocin mutation, R138Q, is associated with early disease onset and rapid progression to end-stage renal disease. Knock-in mice carrying a R140Q mutation, the mouse analogue of human R138Q, show developmental arrest of podocytes and lethal renal failure at neonatal age. Here we created a conditional podocin knock-in model named NPHS2R140Q/-, using a tamoxifen-inducible Cre recombinase, which permits to study the effects of the mutation in postnatal life. Within the first week of R140Q hemizygosity induction the animals developed proteinuria, which peaked after 4–5 weeks. Subsequently the animals developed progressive renal failure, with a median survival time of 12 (95% CI: 11–13) weeks. Foot process fusion was observed within one week, progressing to severe and global effacement in the course of the disease. The number of podocytes per glomerulus gradually diminished to 18% compared to healthy controls 12–16 weeks after induction. The fraction of segmentally sclerosed glomeruli was 25%, 85% and 97% at 2, 4 and 8 weeks, respectively. Severe tubulointerstitial fibrosis was present at later disease stage and was correlated quantitatively with the level of proteinuria at early disease stages. While R140Q podocin mRNA expression was elevated, protein abundance was reduced by more than 50% within one week following induction. Whereas miRNA21 expression persistently increased during the first 4 weeks, miRNA-193a expression peaked 2 weeks after induction. In conclusion, the inducible R140Q-podocin mouse model is an auspicious model of the most common genetic cause of human nephrotic syndrome, with a spontaneous disease course strongly reminiscent of the human disorder. This model constitutes a valuable tool to test the efficacy of novel pharmacological interventions aimed to improve podocyte function and viability and attenuate proteinuria, glomerulosclerosis and progressive renal failure.
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Affiliation(s)
- Mansoureh Tabatabaeifar
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Tanja Wlodkowski
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Ivana Simic
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Helga Denc
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Geraldine Mollet
- INSERM, U1163, Imagine Institute, Laboratory of Hereditary Kidney Diseases, Paris, France
- Paris Descartes-Sorbonne Paris Cité University, Paris, France
| | - Stefanie Weber
- Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, Philipps-University Marburg, Marburg, Germany
| | | | - Barbara Brühl
- Institute for Anatomy and Cell Biology, University of Heidelberg, Heidelberg, Germany
| | - Michael Joseph Randles
- Wellcome Trust Centre for Cell Matrix Research, University of Manchester, Manchester, United Kingdom
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Rachel Lennon
- Wellcome Trust Centre for Cell Matrix Research, University of Manchester, Manchester, United Kingdom
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Corinne Antignac
- INSERM, U1163, Imagine Institute, Laboratory of Hereditary Kidney Diseases, Paris, France
- Paris Descartes-Sorbonne Paris Cité University, Paris, France
- Department of Genetics, Necker Hospital, Assistance Publique—Hôpitaux de Paris, Paris, France
| | - Franz Schaefer
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
- * E-mail:
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23
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Pajęcka K, Nielsen MN, Hansen TK, Williams JM. The formation of quiescent glomerular endothelial cell monolayer in vitro is strongly dependent on the choice of extracellular matrix coating. Exp Cell Res 2017; 353:16-25. [PMID: 28237245 DOI: 10.1016/j.yexcr.2017.02.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 02/12/2017] [Accepted: 02/22/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS Nephropathy involves pathophysiological changes to the glomerulus. The primary glomerular endothelial cells (GEnCs) have emerged as an important tool for studying glomerulosclerotic mechanisms and in the screening process for drug-candidates. The success of the studies is dependent on the quality of the cell model. Therefore, we set out to establish an easy, reproducible model of the quiescent endothelial monolayer with the use of commercially available extracellular matrices (ECMs). METHODS Primary hGEnCs were seeded on various ECMs. Cell adhesion was monitored by an impedance sensing system. The localization of junctional proteins was assessed by immunofluorescence and the barrier function by passage of fluorescent dextrans and magnitude of VEGF response. RESULTS All ECM matrices except recombinant human laminin 111 (rhLN111) supported comparable cell proliferation. Culturing hGEnCs on rhLN521, rhLN511 or fibronectin resulted in a physiologically relevant barrier to 70kDa dextrans which was 82% tighter than that formed on collagen type IV. Furthermore, only hGEnCs cultured on rhLN521 or rhLN511 showed plasma-membrane localized zonula occludens-1 and vascular endothelial cadherin indicative of proper tight and adherens junctions (AJ). CONCLUSION We recommend culturing hGEnCs on the mature glomerular basement membrane laminin - rhLN521 - which, as the only commercially available ECM, promotes all of the characteristics of the quiescent hGEnC monolayer: cobblestone morphology, well-defined AJs and physiological perm-selectivity.
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Affiliation(s)
- Kamilla Pajęcka
- Global Research, Novo Nordisk A/S, Måløv, Denmark; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark.
| | | | - Troels Krarup Hansen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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24
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Yurchenco PD. Integrating Activities of Laminins that Drive Basement Membrane Assembly and Function. CURRENT TOPICS IN MEMBRANES 2015; 76:1-30. [PMID: 26610910 DOI: 10.1016/bs.ctm.2015.05.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Studies on extracellular matrix proteins, cells, and genetically modified animals have converged to reveal mechanisms of basement membrane self-assembly as mediated by γ1 subunit-containing laminins, the focus of this chapter. The basic model is as follows: A member of the laminin family adheres to a competent cell surface and typically polymerizes followed by laminin binding to the extracellular adaptor proteins nidogen, perlecan, and agrin. Assembly is completed by the linking of nidogen and heparan sulfates to type IV collagen, allowing it to form a second stabilizing network polymer. The assembled matrix provides structural support, anchoring the extracellular matrix to the cytoskeleton, and acts as a signaling platform. Heterogeneity of function is created in part by the isoforms of laminin that vary in their ability to polymerize and to interact with integrins, dystroglycan, and other receptors. Mutations in laminin subunits, affecting expression or LN domain-specific functions, are a cause of human diseases that include those of muscle, nerve, brain, and kidney.
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Affiliation(s)
- Peter D Yurchenco
- Department of Pathology & Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA.
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25
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Borza CM, Chen X, Zent R, Pozzi A. Cell Receptor-Basement Membrane Interactions in Health and Disease: A Kidney-Centric View. CURRENT TOPICS IN MEMBRANES 2015; 76:231-53. [PMID: 26610916 PMCID: PMC4913201 DOI: 10.1016/bs.ctm.2015.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell-extracellular matrix (ECM) interactions are essential for tissue development, homeostasis, and response to injury. Basement membranes (BMs) are specialized ECMs that separate epithelial or endothelial cells from stromal components and interact with cells via cellular receptors, including integrins and discoidin domain receptors. Disruption of cell-BM interactions due to either injury or genetic defects in either the ECM components or cellular receptors often lead to irreversible tissue injury and loss of organ function. Animal models that lack specific BM components or receptors either globally or in selective tissues have been used to help with our understanding of the molecular mechanisms whereby cell-BM interactions regulate organ function in physiological and pathological conditions. We review recently published works on animal models that explore how cell-BM interactions regulate kidney homeostasis in both health and disease.
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Affiliation(s)
- Corina M. Borza
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, 37232
| | - Xiwu Chen
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, 37232
| | - Roy Zent
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Medicine, Veterans Administration Hospital, Nashville, TN, 37232
| | - Ambra Pozzi
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, 37232
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Medicine, Veterans Administration Hospital, Nashville, TN, 37232
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26
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Bull KR, Mason T, Rimmer AJ, Crockford TL, Silver KL, Bouriez-Jones T, Hough TA, Chaudhry S, Roberts ISD, Goodnow CC, Cornall RJ. Next-generation sequencing to dissect hereditary nephrotic syndrome in mice identifies a hypomorphic mutation in Lamb2 and models Pierson's syndrome. J Pathol 2014; 233:18-26. [PMID: 24293254 PMCID: PMC4241031 DOI: 10.1002/path.4308] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 11/15/2013] [Accepted: 11/21/2013] [Indexed: 01/11/2023]
Abstract
The study of mutations causing the steroid-resistant nephrotic syndrome in children has greatly advanced our understanding of the kidney filtration barrier. In particular, these genetic variants have illuminated the roles of the podocyte, glomerular basement membrane and endothelial cell in glomerular filtration. However, in a significant number of familial and early onset cases, an underlying mutation cannot be identified, indicating that there are likely to be multiple unknown genes with roles in glomerular permeability. We now show how the combination of N-ethyl-N-nitrosourea mutagenesis and next-generation sequencing could be used to identify the range of mutations affecting these pathways. Using this approach, we isolated a novel mouse strain with a viable nephrotic phenotype and used whole-genome sequencing to isolate a causative hypomorphic mutation in Lamb2. This discovery generated a model for one part of the spectrum of human Pierson’s syndrome and provides a powerful proof of principle for accelerating gene discovery and improving our understanding of inherited forms of renal disease. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd
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Affiliation(s)
- Katherine R Bull
- Nuffield Department of Medicine and Wellcome Trust Centre for Human Genetics, Oxford University, UK
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Lennon R, Randles MJ, Humphries MJ. The importance of podocyte adhesion for a healthy glomerulus. Front Endocrinol (Lausanne) 2014; 5:160. [PMID: 25352829 PMCID: PMC4196579 DOI: 10.3389/fendo.2014.00160] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 09/21/2014] [Indexed: 12/23/2022] Open
Abstract
Podocytes are specialized epithelial cells that cover the outer surfaces of glomerular capillaries. Unique cell junctions, known as slit diaphragms, which feature nephrin and Neph family proteins in addition to components of adherens, tight, and gap junctions, connect adjacent podocyte foot processes. Single gene disorders affecting the slit diaphragm result in nephrotic syndrome in humans, characterized by massive loss of protein across the capillary wall. In addition to specialized cell junctions, interconnecting podocytes also adhere to the glomerular basement membrane (GBM) of the capillary wall. The GBM is a dense network of secreted, extracellular matrix (ECM) components and contains tissue-restricted isoforms of collagen IV and laminin in addition to other structural proteins and ECM regulators such as proteases and growth factors. The specialized niche of the GBM provides a scaffold for endothelial cells and podocytes to support their unique functions and human genetic mutations in GBM components lead to renal failure, thus highlighting the importance of cell-matrix interactions in the glomerulus. Cells adhere to ECM via adhesion receptors, including integrins, syndecans, and dystroglycan and in particular the integrin heterodimer α3β1 is required to maintain barrier integrity. Therefore, the sophisticated function of glomerular filtration relies on podocyte adhesion both at cell junctions and at the interface with the ECM. In health, the podocyte coordinates signals from cell junctions and cell-matrix interactions, in response to environmental cues in order to regulate filtration and as our understanding of mechanisms that control cell adhesion in the glomerulus develops, then insight into the effects of disease will improve. The ultimate goal will be to develop targeted therapies to prevent or repair defects in the filtration barrier and to restore glomerular function.
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Affiliation(s)
- Rachel Lennon
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, UK
- Institute of Human Development, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
- Department of Paediatric Nephrology, Manchester Academic Health Science Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK
- *Correspondence: Rachel Lennon, Wellcome Trust Centre for Cell-Matrix Research, The University of Manchester, Michael Smith Building, Manchester M13 9PT, UK e-mail:
| | - Michael J. Randles
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, UK
- Institute of Human Development, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - Martin J. Humphries
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, UK
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28
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Animal models of nephrotic syndrome. Pediatr Nephrol 2013; 28:2079-88. [PMID: 23250714 DOI: 10.1007/s00467-012-2376-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 10/25/2012] [Accepted: 10/25/2012] [Indexed: 12/28/2022]
Abstract
Animal models of proteinuria and nephrotic syndrome are essential tools for studying the mechanisms of action of abnormalities in individual components of the podocyte and glomerular basement membrane. In recent years a variety of in vivo models have been developed to elucidate the function of specific podocyte proteins and their role in the pathogenesis of proteinuria and glomerulosclerosis. In this overview of the animal models currently available we discuss their contribution to our mechanistic understanding and their potential use in screening for novel targeted therapies of steroid-resistant nephrotic syndrome.
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Brambilla F, Lavatelli F, Di Silvestre D, Valentini V, Palladini G, Merlini G, Mauri P. Shotgun Protein Profile of Human Adipose Tissue and Its Changes in Relation to Systemic Amyloidoses. J Proteome Res 2013; 12:5642-55. [DOI: 10.1021/pr400583h] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
| | - Francesca Lavatelli
- Amyloid
Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | | | - Veronica Valentini
- Amyloid
Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Giovanni Palladini
- Amyloid
Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
- Department
of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Giampaolo Merlini
- Amyloid
Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
- Department
of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Pierluigi Mauri
- Institute for Biomedical Technologies (ITB-CNR), Segrate, Italy
- Institute of Life Sciences, Scuola
Superiore Sant’Anna, Pisa, Italy
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30
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Abstract
The glomerular basement membrane (GBM) is the central, non-cellular layer of the glomerular filtration barrier that is situated between the two cellular components--fenestrated endothelial cells and interdigitated podocyte foot processes. The GBM is composed primarily of four types of extracellular matrix macromolecule--laminin-521, type IV collagen α3α4α5, the heparan sulphate proteoglycan agrin, and nidogen--which produce an interwoven meshwork thought to impart both size-selective and charge-selective properties. Although the composition and biochemical nature of the GBM have been known for a long time, the functional importance of the GBM versus that of podocytes and endothelial cells for establishing the glomerular filtration barrier to albumin is still debated. Together with findings from genetic studies in mice, the discoveries of four human mutations affecting GBM components in two inherited kidney disorders, Alport syndrome and Pierson syndrome, support essential roles for the GBM in glomerular permselectivity. Here, we explain in detail the proposed mechanisms whereby the GBM can serve as the major albumin barrier and discuss possible approaches to circumvent GBM defects associated with loss of permselectivity.
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Arif E, Nihalani D. Glomerular Filtration Barrier Assembly: An insight. POSTDOC JOURNAL : A JOURNAL OF POSTDOCTORAL RESEARCH AND POSTDOCTORAL AFFAIRS 2013; 1:33-45. [PMID: 27583259 PMCID: PMC5003421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A glomerulus is the network of capillaries that resides in the Bowman's capsule that functions as a filtration unit of kidney. The glomerular function ensures that essential plasma proteins are retained in blood and the filtrate is passed on as urine. The glomerular filtration assembly is composed of three main cellular barriers that are critical for the ultrafiltration process, the fenestrated endothelium, glomerular basement membrane and highly specialized podocytes. The podocytes along with their specialized junctions "slit diaphragm" form the basic backbone of this filtration assembly. The presence of high amounts of protein in urine a condition commonly referred as proteinuria indicates a defective glomerular filtration barrier. Various glomerular disorders including Nephrotic syndrome are characterized by significant alteration in the structure of podocytes that is associated with prolonged increase in the glomerular permeability leading to heavy proteinuria. Recent identification of proteins that are specifically localized at the slit diaphragm whose mutations and knockouts are known to result in loss of renal function has significantly advanced our understanding of the molecular makeup of this filtration assembly. The present review is an effort to summarize the recent developments in this field and highlight our understanding of the glomerular filtration barrier assembly.
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Affiliation(s)
- Ehtesham Arif
- Renal Electrolytes and Hypertension Division, University of Pennsylvania, Philadelphia, PA 19104
| | - Deepak Nihalani
- Renal Electrolytes and Hypertension Division, University of Pennsylvania, Philadelphia, PA 19104
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Sachs N, Sonnenberg A. Cell-matrix adhesion of podocytes in physiology and disease. Nat Rev Nephrol 2013; 9:200-10. [PMID: 23338211 DOI: 10.1038/nrneph.2012.291] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cell-matrix adhesion is crucial for maintaining the mechanical integrity of epithelial tissues. Podocytes--a key component of the glomerular filtration barrier--are exposed to permanent transcapillary filtration pressure and must therefore adhere tightly to the underlying glomerular basement membrane (GBM). The major cell-matrix adhesion receptor in podocytes is the integrin α3β1, which connects laminin 521 in the GBM through various adaptor proteins to the intracellular actin cytoskeleton. Other cell-matrix adhesion receptors expressed by podocytes include the integrins α2β1 and αvβ3, α-dystroglycan, syndecan-4 and type XVII collagen. Mutations in genes encoding any of the components critical for podocyte adhesion cause glomerular disease. This Review highlights recent advances in our understanding of the cell biology and genetics of podocyte adhesion with special emphasis on glomerular disease.
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Affiliation(s)
- Norman Sachs
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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Abstract
A chain is no stronger than its weakest link is an old idiom that holds true for muscle biology. As the name implies, skeletal muscle's main function is to move the bones. However, for a muscle to transmit force and withstand the stress that contractions give rise to, it relies on a chain of proteins attaching the cytoskeleton of the muscle fiber to the surrounding extracellular matrix. The importance of this attachment is illustrated by a large number of muscular dystrophies caused by interruption of the cytoskeletal-extracellular matrix interaction. One of the major components of the extracellular matrix is laminin, a heterotrimeric glycoprotein and a major constituent of the basement membrane. It has become increasingly apparent that laminins are involved in a multitude of biological functions, including cell adhesion, differentiation, proliferation, migration and survival. This review will focus on the importance of laminin-211 for normal skeletal muscle function.
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Affiliation(s)
- Johan Holmberg
- Muscle Biology Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden.
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Crystal structures of the network-forming short-arm tips of the laminin β1 and γ1 chains. PLoS One 2012; 7:e42473. [PMID: 22860131 PMCID: PMC3409155 DOI: 10.1371/journal.pone.0042473] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 07/06/2012] [Indexed: 01/11/2023] Open
Abstract
The heterotrimeric laminins are a defining component of basement membranes and essential for tissue formation and function in all animals. The three short arms of the cross-shaped laminin molecule are composed of one chain each and their tips mediate the formation of a polymeric network. The structural basis for laminin polymerisation is unknown. We have determined crystal structures of the short-arm tips of the mouse laminin β1 and γ1 chains, which are grossly similar to the previously determined structure of the corresponding α5 chain region. The short-arm tips consist of a laminin N-terminal (LN) domain that is attached like the head of a flower to a rod-like stem formed by tandem laminin-type epidermal growth factor-like (LE) domains. The LN domain is a β-sandwich with elaborate loop regions that differ between chains. The γ1 LN domain uniquely contains a calcium binding site. The LE domains have little regular structure and are stabilised by cysteines that are disulphide-linked 1–3, 2–4, 5–6 and 7–8 in all chains. The LN surface is not conserved across the α, β and γ chains, but within each chain subfamily there is a striking concentration of conserved residues on one face of the β-sandwich, while the opposite face invariably is shielded by glycans. We propose that the extensive conserved patches on the β and γ LN domains mediate the binding of these two chains to each other, and that the α chain LN domain subsequently binds to the composite β-γ surface. Mutations in the laminin β2 LN domain causing Pierson syndrome are likely to impair the folding of the β2 chain or its ability to form network interactions.
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Progress in pathogenesis of proteinuria. Int J Nephrol 2012; 2012:314251. [PMID: 22693670 PMCID: PMC3368192 DOI: 10.1155/2012/314251] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Revised: 03/24/2012] [Accepted: 03/26/2012] [Indexed: 02/06/2023] Open
Abstract
Aims. Proteinuria not only is a sign of kidney damage, but also is involved in the progression of renal diseases as an independent pathologic factor. Clinically, glomerular proteinuria is most commonly observed, which relates to structural and functional anomalies in the glomerular filtration barrier. The aim of this paper was to describe the pathogenesis of glomerular proteinuria. Data Sources. Articles on glomerular proteinuria retrieved from Pubmed and MEDLINE in the recent 5 years were reviewed. Results. The new understanding of the roles of glomerular endothelial cells and the glomerular basement membrane (GBM) in the pathogenesis of glomerular proteinuria was gained. The close relationships of slit diaphragm (SD) molecules such as nephrin, podocin, CD2-associated protein (CD2AP), a-actinin-4, transient receptor potential cation channel 6 (TRPC6), Densin and membrane-associated guanylate kinase inverted 1 (MAGI-1), α3β1 integrin, WT1, phospholipase C epsilon-1 (PLCE1), Lmx1b, and MYH9, and mitochondrial disorders and circulating factors in the pathogenesis of glomerular proteinuria were also gradually discovered. Conclusion. Renal proteinuria is a manifestation of glomerular filtration barrier dysfunction. Not only glomerular endothelial cells and GBM, but also the glomerular podocytes and their SDs play an important role in the pathogenesis of glomerular proteinuria.
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Schaeffer V, Hansen KM, Morris DR, LeBoeuf RC, Abrass CK. RNA-binding protein IGF2BP2/IMP2 is required for laminin-β2 mRNA translation and is modulated by glucose concentration. Am J Physiol Renal Physiol 2012; 303:F75-82. [PMID: 22513850 DOI: 10.1152/ajprenal.00185.2012] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Laminin-β2 (LAMB2) is a critical component of the glomerular basement membrane as content of LAMB2 in part determines glomerular barrier permeability. Previously, we reported that high concentrations of glucose reduce expression of this laminin subunit at the translational level. The present studies were undertaken to further define systems that control Lamb2 translation and the effect of high glucose on those systems. Complementary studies were performed using in vitro differentiation of cultured podocytes and mesangial cells exposed to normal and elevated concentrations of glucose, and tissues from control and diabetic rats. Together, these studies provide evidence for regulation of Lamb2 translation by IMP2, an RNA binding protein that targets Lamb2 mRNA to the actin cytoskeleton. Expression of Imp2 itself is regulated by the transcription factor HMGA2, which in turn is regulated by the microRNA let-7b. Elevated concentrations of glucose increase let-7b, which reduces HMGA2 expression, in turn reducing IMP2 and LAMB2. Correlative changes in kidney tissues from control and streptozotocin-induced diabetic rats suggest these control mechanisms are operative in vivo and may contribute to proteinuria in diabetic nephropathy. To our knowledge, this is the first time that translation of Lamb2 mRNA has been linked to the actin cytoskeleton, as well as to specific RNA-binding proteins. These translational control points may provide new targets for therapy in proteinuric disorders such as diabetic nephropathy where LAMB2 levels are reduced.
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Affiliation(s)
- Valerie Schaeffer
- Primary and Specialty Care Medicine, Department of Veterans Affairs Puget Sound Health Care System, Seattle, Washington, USA
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37
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Miner JH. The glomerular basement membrane. Exp Cell Res 2012; 318:973-8. [PMID: 22410250 DOI: 10.1016/j.yexcr.2012.02.031] [Citation(s) in RCA: 192] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 02/24/2012] [Indexed: 11/30/2022]
Abstract
The kidney's glomerular filtration barrier consists of two cells-podocytes and endothelial cells-and the glomerular basement membrane (GBM), a specialized extracellular matrix that lies between them. Like all basement membranes, the GBM consists mainly of laminin, type IV collagen, nidogen, and heparan sulfate proteoglycan. However, the GBM is unusually thick and contains particular members of these general protein families, including laminin-521, collagen α3α4α5(IV), and agrin. Knockout studies in mice and genetic findings in humans show that the laminin and type IV collagen components are particularly important for GBM structure and function, as laminin or collagen IV gene mutations cause filtration defects and renal disease of varying severities, depending on the nature of the mutations. These studies suggest that the GBM plays a crucial role in establishing and maintaining the glomerular filtration barrier.
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Affiliation(s)
- Jeffrey H Miner
- Renal Division and Dept. of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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