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Wang Y, He QN. [Research progress on monogenic inherited glomerular diseases with central nervous system symptoms]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2024; 26:652-658. [PMID: 38926384 DOI: 10.7499/j.issn.1008-8830.2312054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
To date, approximately 500 monogenic inherited kidney diseases have been reported, with more than 50 genes associated with the pathogenesis of monogenic isolated or syndromic nephrotic syndrome. Most of these genes are expressed in podocytes of the glomerulus. Neurological symptoms are common extrarenal manifestations of syndromic nephrotic syndrome, and various studies have found connections between podocytes and neurons in terms of morphology and function. This review summarizes the genetic and clinical characteristics of monogenic inherited diseases with concomitant glomerular and central nervous system lesions, aiming to enhance clinicians' understanding of such diseases, recognize the importance of genetic diagnostic techniques for comorbidity screening, and reduce the rates of missed diagnosis and misdiagnosis.
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Affiliation(s)
- Ying Wang
- Department of Pediatrics, Third Xiangya Hospital, Central South University, Changsha 410013, China
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Conradt G, Hausser I, Nyström A. Epidermal or Dermal Collagen VII Is Sufficient for Skin Integrity: Insights to Anchoring Fibril Homeostasis. J Invest Dermatol 2024; 144:1301-1310.e7. [PMID: 38007090 DOI: 10.1016/j.jid.2023.11.003] [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: 09/13/2023] [Revised: 10/26/2023] [Accepted: 11/01/2023] [Indexed: 11/27/2023]
Abstract
Collagen VII forms anchoring fibrils that are essential for the stability of the skin and other epithelial organs. In addition to such structural functions, it is emerging that collagen VII fills instructive functions. Collagen VII is synthesized by both epithelial cells and fibroblasts. Genetic loss of collagen VII causes dystrophic epidermolysis bullosa, which manifests with chronic skin fragility and fibrosis. Significant progress has been made in developing therapies for dystrophic epidermolysis bullosa; however, such work has also raised questions on the importance of the cellular source of collagen VII for maintenance of tissue integrity and homeostasis. Toward this end, we engineered mice that kept the physiological expression of collagen VII only in epithelial cells or in fibroblasts. Our study revealed that production of collagen VII either by keratinocytes or fibroblasts alone is sufficient for creation of mechanically robust skin. Importantly, we also show tissue-diverse dependence on epithelial and mesenchymal production of collagen VII and provide support for limited amounts of collagen VII being sufficient for tissue protection. Furthermore, a disconnect between collagen VII abundance and anchoring fibril numbers supports the concept that restoration of fully physiological collagen VII levels may not be needed to achieve complete mechanical protection of dystrophic epidermolysis bullosa skin.
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Affiliation(s)
- Gregor Conradt
- Department of Dermatology, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany; Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ingrid Hausser
- Institute of Pathology, Heidelberg University Hospital, Heidelberg, Germany
| | - Alexander Nyström
- Department of Dermatology, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany.
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Oda K, Katayama K, Zang L, Toda M, Tanoue A, Saiki R, Yasuma T, D’Alessandro-Gabazza CN, Shimada Y, Mori M, Suzuki Y, Murata T, Hirai T, Tryggvason K, Gabazza EC, Dohi K. The Protective Role of KANK1 in Podocyte Injury. Int J Mol Sci 2024; 25:5808. [PMID: 38891998 PMCID: PMC11172089 DOI: 10.3390/ijms25115808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 05/21/2024] [Accepted: 05/25/2024] [Indexed: 06/21/2024] Open
Abstract
Approximately 30% of steroid-resistant nephrotic syndromes are attributed to monogenic disorders that involve 27 genes. Mutations in KANK family members have also been linked to nephrotic syndrome; however, the precise mechanism remains elusive. To investigate this, podocyte-specific Kank1 knockout mice were generated to examine phenotypic changes. In the initial assessment under normal conditions, Kank1 knockout mice showed no significant differences in the urinary albumin-creatinine ratio, blood urea nitrogen, serum creatinine levels, or histological features compared to controls. However, following kidney injury with adriamycin, podocyte-specific Kank1 knockout mice exhibited a significantly higher albumin-creatinine ratio and a significantly greater sclerotic index than control mice. Electron microscopy revealed more extensive foot process effacement in the knockout mice than in control mice. In addition, KANK1-deficient human podocytes showed increased detachment and apoptosis following adriamycin exposure. These findings suggest that KANK1 may play a protective role in mitigating podocyte damage under pathological conditions.
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Affiliation(s)
- Keiko Oda
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (K.O.); (A.T.); (R.S.); (M.M.); (Y.S.); (T.M.); (K.D.)
| | - Kan Katayama
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (K.O.); (A.T.); (R.S.); (M.M.); (Y.S.); (T.M.); (K.D.)
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Stockholm, Sweden;
| | - Liqing Zang
- Graduate School of Regional Innovation Studies, Mie University, Tsu 514-8507, Mie, Japan;
| | - Masaaki Toda
- Department of Immunology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (M.T.); (T.Y.); (C.N.D.-G.); (E.C.G.)
| | - Akiko Tanoue
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (K.O.); (A.T.); (R.S.); (M.M.); (Y.S.); (T.M.); (K.D.)
| | - Ryosuke Saiki
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (K.O.); (A.T.); (R.S.); (M.M.); (Y.S.); (T.M.); (K.D.)
| | - Taro Yasuma
- Department of Immunology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (M.T.); (T.Y.); (C.N.D.-G.); (E.C.G.)
| | - Corina N. D’Alessandro-Gabazza
- Department of Immunology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (M.T.); (T.Y.); (C.N.D.-G.); (E.C.G.)
| | - Yasuhito Shimada
- Department of Integrative Pharmacology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan;
| | - Mutsuki Mori
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (K.O.); (A.T.); (R.S.); (M.M.); (Y.S.); (T.M.); (K.D.)
| | - Yasuo Suzuki
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (K.O.); (A.T.); (R.S.); (M.M.); (Y.S.); (T.M.); (K.D.)
| | - Tomohiro Murata
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (K.O.); (A.T.); (R.S.); (M.M.); (Y.S.); (T.M.); (K.D.)
| | - Toshinori Hirai
- Department of Pharmacy, Faculty of Medicine, Mie University Hospital, Tsu 514-8507, Mie, Japan;
| | - Karl Tryggvason
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Stockholm, Sweden;
| | - Esteban C. Gabazza
- Department of Immunology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (M.T.); (T.Y.); (C.N.D.-G.); (E.C.G.)
| | - Kaoru Dohi
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan; (K.O.); (A.T.); (R.S.); (M.M.); (Y.S.); (T.M.); (K.D.)
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Kuang H, Shen CR, Jia XY, Tan M, Yang XF, Cui Z, Borza DB, Zhao MH. Autoantibodies against laminin-521 are pathogenic in anti-glomerular basement membrane disease. Kidney Int 2023; 104:1124-1134. [PMID: 37598856 PMCID: PMC10840746 DOI: 10.1016/j.kint.2023.07.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/19/2023] [Accepted: 07/28/2023] [Indexed: 08/22/2023]
Abstract
Anti-glomerular basement membrane (anti-GBM) disease is an organ-specific autoimmune disorder characterized by autoantibodies against GBM components. Evidence from human inherited kidney diseases and animal models suggests that the α, β, and γ chains of laminin-521 are all essential for maintaining the glomerular filtration barrier. We previously demonstrated that laminin-521 is a novel autoantigen within the GBM and that autoantibodies to laminin-521 are present in about one-third of patients. In the present study, we investigated the pathogenicity of autoantibodies against laminin-521 with clinical and animal studies. Herein, a rare case of anti-GBM disease was reported with circulating autoantibodies binding to laminin-521 but not to the NC1 domains of α1-α5(IV) collagen. Immunoblot identified circulating IgG from this patient bound laminin α5 and γ1 chains. A decrease in antibody levels was associated with improved clinical presentation after plasmapheresis and immunosuppressive treatments. Furthermore, immunization with laminin-521 in female Wistar-Kyoto rats induced crescentic glomerulonephritis with linear IgG deposits along the GBM, complement activation along with infiltration of T cells and macrophages. Lung hemorrhage occurred in 75.0% of the rats and was identified by the presence of erythrocyte infiltrates and hemosiderin-laden macrophages in the lung tissue. Sera and kidney-eluted antibodies from rats immunized with laminin-521 demonstrated specific IgG binding to laminin-521 but not to human α3(IV)NC1, while the opposite was observed in human α3(IV)NC1-immunized rats. Thus, our patient data and animal studies imply a possible independent pathogenic role of autoantibodies against laminin-521 in the development of anti-GBM disease.
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Affiliation(s)
- Huang Kuang
- Renal Division, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education of China, Beijing, China; Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Cong-Rong Shen
- Renal Division, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education of China, Beijing, China; Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China; Department of Urology, China-Japan Friendship Hospital, Beijing, China
| | - Xiao-Yu Jia
- Renal Division, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education of China, Beijing, China; Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China.
| | - Meng Tan
- Renal Division, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education of China, Beijing, China; Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Xue-Fen Yang
- Renal Division, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education of China, Beijing, China; Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China; Renal Division, Shanxi Medical University Second Hospital, Shanxi Kidney Disease Institute, Taiyuan, China
| | - Zhao Cui
- Renal Division, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education of China, Beijing, China; Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Dorin-Bogdan Borza
- Department of Microbiology, Immunology and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Ming-Hui Zhao
- Renal Division, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education of China, Beijing, China; Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
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Xie Y, Li X, Deng W, Nan N, Zou H, Gong L, Chen M, Yu J, Chen P, Cui D, Zhang F. Knockdown of USF2 inhibits pyroptosis of podocytes and attenuates kidney injury in lupus nephritis. J Mol Histol 2023; 54:313-327. [PMID: 37341818 DOI: 10.1007/s10735-023-10135-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 06/11/2023] [Indexed: 06/22/2023]
Abstract
As an essential factor in the prognosis of Systemic lupus erythematosus (SLE), lupus nephritis (LN) can accelerate the rate at which patients with SLE can transition to chronic kidney disease or even end-stage renal disease (ESRD). Proteinuria due to decreased glomerular filtration rate following podocyte injury is LN's most common clinical manifestation. Podocyte pyroptosis and related inflammatory factors in its process can promote lupus to involve kidney cells and worsen the occurrence and progression of LN, but its regulatory mechanism remains unknown. Accumulating evidence has shown that upstream stimulatory factor 2 (USF2) plays a vital role in the pathophysiology of kidney diseases. In this research, multiple experiments were performed to investigate the role of USF2 in the process of LN. USF2 was abnormally highly expressed in MRL/lpr mice kidney tissues. Renal function impairment and USF2 mRNA levels were positively correlated. Silencing of USF2 in MRL/lpr serum-stimulated cells significantly reduced serum-induced podocyte pyroptosis. USF2 enhanced NLRP3 expression at the transcriptional level. Silencing of USF2 in vivo attenuated kidney injury in MRL/lpr mice, which suggests that USF2 is important for LN development and occurrence.
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Affiliation(s)
- Ying Xie
- Department of Pathophysiology, Guizhou Medical University, Guiyang, 550025, China
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, 550025, China
| | - Xiaoying Li
- Department of Nephrology, The First People's Hospital of Guiyang, Guiyang, 550002, China
| | - Wenli Deng
- Department of Nephrology, The First People's Hospital of Guiyang, Guiyang, 550002, China
| | - Nan Nan
- Department of Pathology, The First People's Hospital of Guiyang, Guiyang, 550002, China
| | - Huimei Zou
- Department of Pathophysiology, Guizhou Medical University, Guiyang, 550025, China
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, 550025, China
- School of Nursing, Guizhou Medical University, Guiyang, 550025, China
| | - Lei Gong
- Department of Basic Medicine, Qujing Medical College, Qujing, 655000, China
| | - Min Chen
- Department of Pathophysiology, Guizhou Medical University, Guiyang, 550025, China
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, 550025, China
| | - Jie Yu
- Department of Pathophysiology, Guizhou Medical University, Guiyang, 550025, China
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, 550025, China
| | - Peilei Chen
- Department of Pathophysiology, Guizhou Medical University, Guiyang, 550025, China
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, 550025, China
| | - Daolin Cui
- Department of Basic Medicine, Qujing Medical College, Qujing, 655000, China.
| | - Fan Zhang
- Department of Pathophysiology, Guizhou Medical University, Guiyang, 550025, China.
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, 550025, China.
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Smith DW, Azadi A, Lee CJ, Gardiner BS. Spatial composition and turnover of the main molecules in the adult glomerular basement membrane. Tissue Barriers 2023; 11:2110798. [PMID: 35959954 PMCID: PMC10364650 DOI: 10.1080/21688370.2022.2110798] [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: 03/22/2022] [Revised: 07/31/2022] [Accepted: 08/03/2022] [Indexed: 10/15/2022] Open
Abstract
The glomerular basement membrane (GBM) is an important tissue structure in kidney function. It is the membrane through which filtrate and solutes must pass to reach the nephron tubules. This review focuses on the spatial location of the main extracellular matrix components of the GBM. It also attempts to explain this organization in terms of their synthesis, transport, and loss. The picture that emerges is that the collagen IV and laminin content of GBM are in a very slow dynamic disequilibrium, leading to GBM thickening with age, and in contrast, some heparan sulfate proteoglycans are in a dynamic equilibrium with a very rapid turnover (i.e. half-life measured in ~hours) and flow direction against the flow of filtrate. The highly rapid heparan sulfate turnover may serve several roles, including an unclogging mechanism for the GBM, compressive stiffness of the GBM fiber network, and/or enabling podocycte-endothelial crosstalk against the flow of filtrate.
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Affiliation(s)
- David W. Smith
- Faculty of Engineering and Mathematical Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Azin Azadi
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch, Western Australia, Australia
| | - Chang-Joon Lee
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch, Western Australia, Australia
| | - Bruce S. Gardiner
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch, Western Australia, Australia
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Reiterová J, Tesař V. Current and Future Therapeutical Options in Alport Syndrome. Int J Mol Sci 2023; 24:5522. [PMID: 36982595 PMCID: PMC10056269 DOI: 10.3390/ijms24065522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 03/18/2023] Open
Abstract
Alport syndrome (AS) is a hereditary kidney disease caused by pathogenic variants in COL4A3 and COL4A4 genes with autosomal recessive or autosomal dominant transmission or in the COL4A5 gene with X-linked inheritance. Digenic inheritance was also described. Clinically it is associated with microscopic hematuria, followed by proteinuria and chronic renal insufficiency with end-stage renal disease in young adults. Nowadays, there is no curative treatment available. The inhibitors of RAS (renin-angiotensin system) since childhood slow the progression of the disease. Sodium-glucose cotransporter-2 inhibitors seem to be promising drugs from DAPA-CKD (dapagliflozin-chronic kidney disease) study, but only a limited number of patients with Alport syndrome was included. Endothelin type A receptor and angiotensin II type 1 receptor combined inhibitors, and lipid-lowering agents are used in ongoing studies in patients with AS and focal segmental glomerulosclerosis (FSGS). Hydroxychloroquine in AS is studied in a clinical trial in China. Molecular genetic diagnosis of AS is crucial not only for prognosis prediction but also for future therapeutic options. Different types of mutations will require various types of gene, RNA, or protein therapy to improve the function, the of final protein product.
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Affiliation(s)
- Jana Reiterová
- Department of Nephrology, First Faculty of Medicine, Charles University, General University Hospital in Prague, 128 08 Prague, Czech Republic
- First Faculty of Medicine, Institute of Biology and Medical Genetics, Charles University, General University Hospital in Prague, 128 08 Prague, Czech Republic
| | - Vladimír Tesař
- Department of Nephrology, First Faculty of Medicine, Charles University, General University Hospital in Prague, 128 08 Prague, Czech Republic
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Siegerist F, Drenic V, Koppe TM, Telli N, Endlich N. Super-Resolution Microscopy: A Technique to Revolutionize Research and Diagnosis of Glomerulopathies. GLOMERULAR DISEASES 2022; 3:19-28. [PMID: 36816428 PMCID: PMC9936760 DOI: 10.1159/000528713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
Background For decades, knowledge about glomerular (patho)physiology has been tightly linked with advances in microscopic imaging technology. For example, the invention of electron microscopy was required to hypothesize about the mode of glomerular filtration barrier function. Summary Super-resolution techniques, defined as fluorescence microscopy approaches that surpass the optical resolution limit of around 200 nm, have been made available to the scientific community. Several of these different techniques are currently in use in glomerular research. Using three-dimensional structured illumination microscopy, the exact morphology of the podocyte filtration slit can be morphometrically analyzed and quantitatively compared across samples originating from animal models or human biopsies. Key Messages Several quantitative image analysis approaches and their potential influence on glomerular research and diagnostics are discussed. By improving not only optical resolution but also information content and turnaround time, super-resolution microscopy has the potential to expand the diagnosis of glomerular disease. Soon, these approaches could be introduced into glomerular disease diagnosis.
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Affiliation(s)
- Florian Siegerist
- Institute for Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | | | - Thor-Magnus Koppe
- Institute for Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | | | - Nicole Endlich
- Institute for Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany,NIPOKA GmbH, Greifswald, Germany,*Nicole Endlich,
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Ruan J, McKee KK, Yurchenco PD, Yao Y. Exogenous laminin exhibits a unique vascular pattern in the brain via binding to dystroglycan and integrins. Fluids Barriers CNS 2022; 19:97. [PMID: 36463265 PMCID: PMC9719645 DOI: 10.1186/s12987-022-00396-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: 08/16/2022] [Accepted: 11/28/2022] [Indexed: 12/07/2022] Open
Abstract
BACKGROUND Unlike other proteins that exhibit a diffusion pattern after intracerebral injection, laminin displays a vascular pattern. It remains unclear if this unique vascular pattern is caused by laminin-receptor interaction or laminin self-assembly. METHODS We compared the distribution of various wild-type laminin isoforms in the brain after intracerebral injection. To determine what causes the unique vascular pattern of laminin in the brain, laminin mutants with impaired receptor-binding and/or self-assembly activities and function-blocking antibodies to laminin receptors were used. In addition, the dynamics of laminin distribution and elimination were examined at multiple time points after intracerebral injection. RESULTS We found that β2-containing laminins had higher affinity for the vessels compared to β1-containing laminins. In addition, laminin mutants lacking receptor-binding domains but not that lacking self-assembly capability showed substantially reduced vascular pattern. Consistent with this finding, dystroglycan (DAG1) function-blocking antibody significantly reduced the vascular pattern of wild-type laminin-111. Although failed to affect the vascular pattern when used alone, integrin-β1 function-blocking antibody further decreased the vascular pattern when combined with DAG1 antibody. EDTA, which impaired laminini-DAG1 interaction by chelating Ca2+, also attenuated the vascular pattern. Immunohistochemistry revealed that laminins were predominantly located in the perivascular space in capillaries and venules/veins but not arterioles/arteries. The time-course study showed that laminin mutants with impaired receptor-engaging activity were more efficiently eliminated from the brain compared to their wild-type counterparts. Concordantly, significantly higher levels of mutant laminins were detected in the cerebral-spinal fluid (CSF). CONCLUSIONS These findings suggest that intracerebrally injected laminins are enriched in the perivascular space in a receptor (DAG1/integrin)-dependent rather than self-assembly-dependent manner and eliminated from the brain mainly via the perivascular clearance system.
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Affiliation(s)
- Jingsong Ruan
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, Tampa, FL, 33612, USA
| | - Karen K McKee
- Department of Pathology and Laboratory Medicine, Rutgers University-Robert W. Johnson Medical School, Piscataway, NJ, USA
| | - Peter D Yurchenco
- Department of Pathology and Laboratory Medicine, Rutgers University-Robert W. Johnson Medical School, Piscataway, NJ, USA
| | - Yao Yao
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, Tampa, FL, 33612, USA.
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Boudko SP, Pokidysheva E, Hudson BG. Prospective collagen IVα345 therapies for Alport syndrome. Curr Opin Nephrol Hypertens 2022; 31:213-220. [PMID: 35283436 PMCID: PMC9159491 DOI: 10.1097/mnh.0000000000000789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
PURPOSE OF REVIEW In Alport syndrome, over 1,700 genetic variants in the COL4A3, COL4A4, and COL4A5 genes cause the absence or malfunctioning of the collagen IVα345 scaffold - an essential component of the glomerular basement membrane (GBM). Therapies are limited to treatment with Angiotensin-Converting enzyme (ACE) inhibitors to slow progression of the disease. Here, we review recent progress in therapy development to replace the scaffold or restore its function. RECENT FINDINGS Multiple approaches emerged recently for development of therapies that target different stages of production and assembly of the collagen IVα345 scaffold in the GBM. These approaches are based on (1) recent advances in technologies allowing to decipher pathogenic mechanisms that underlie scaffold assembly and dysfunction, (2) development of DNA editing tools for gene therapy, (3) RNA splicing interference, and (4) control of mRNA translation. SUMMARY There is a growing confidence that these approaches will ultimately provide cure for Alport patients. The development of therapy will be accelerated by studies that provide a deeper understanding of mechanisms that underlie folding, assembly, and function of the collagen IVα345 scaffold.
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Affiliation(s)
- Sergei P. Boudko
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Elena Pokidysheva
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Billy G. Hudson
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA; Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee, USA
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11
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Falcone S, Nicol T, Blease A, Randles MJ, Angus E, Page A, Tam FWK, Pusey CD, Lennon R, Potter PK. A novel model of nephrotic syndrome results from a point mutation in Lama5 and is modified by genetic background. Kidney Int 2022; 101:527-540. [PMID: 34774562 PMCID: PMC8883398 DOI: 10.1016/j.kint.2021.10.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/22/2021] [Accepted: 10/18/2021] [Indexed: 11/22/2022]
Abstract
Nephrotic syndrome is characterized by severe proteinuria, hypoalbuminaemia, edema and hyperlipidaemia. Genetic studies of nephrotic syndrome have led to the identification of proteins playing a crucial role in slit diaphragm signaling, regulation of actin cytoskeleton dynamics and cell-matrix interactions. The laminin α5 chain is essential for embryonic development and, in association with laminin β2 and laminin γ1, is a major component of the glomerular basement membrane, a critical component of the glomerular filtration barrier. Mutations in LAMA5 were recently identified in children with nephrotic syndrome. Here, we have identified a novel missense mutation (E884G) in the uncharacterized L4a domain of LAMA5 where homozygous mice develop nephrotic syndrome with severe proteinuria with histological and ultrastructural changes in the glomerulus mimicking the progression seen in most patients. The levels of LAMA5 are reduced in vivo and the assembly of the laminin 521 heterotrimer significantly reduced in vitro. Proteomic analysis of the glomerular extracellular fraction revealed changes in the matrix composition. Importantly, the genetic background of the mice had a significant effect on aspects of disease progression from proteinuria to changes in podocyte morphology. Thus, our novel model will provide insights into pathologic mechanisms of nephrotic syndrome and pathways that influence the response to a dysfunctional glomerular basement membrane that may be important in a range of kidney diseases.
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Affiliation(s)
- Sara Falcone
- Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK; Centre for Cellular and Molecular Physiology, University of Oxford, Oxford, UK
| | - Thomas Nicol
- Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK; British Heart Foundation, Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Andrew Blease
- Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK
| | - Michael J Randles
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Elizabeth Angus
- Biomedical Imaging Unit, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Anton Page
- Biomedical Imaging Unit, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Frederick W K Tam
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, London, UK
| | - Charles D Pusey
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, London, UK
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Paul K Potter
- Mammalian Genetics Unit, Medical Research Council Harwell Institute, Harwell Campus, Oxfordshire, UK; Department Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, UK.
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12
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Ravaglia F, Melica ME, Angelotti ML, De Chiara L, Romagnani P, Lasagni L. The Pathology Lesion Patterns of Podocytopathies: How and why? Front Cell Dev Biol 2022; 10:838272. [PMID: 35281116 PMCID: PMC8907833 DOI: 10.3389/fcell.2022.838272] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
Podocytopathies are a group of proteinuric glomerular disorders driven by primary podocyte injury that are associated with a set of lesion patterns observed on kidney biopsy, i.e., minimal changes, focal segmental glomerulosclerosis, diffuse mesangial sclerosis and collapsing glomerulopathy. These unspecific lesion patterns have long been considered as independent disease entities. By contrast, recent evidence from genetics and experimental studies demonstrated that they represent signs of repeated injury and repair attempts. These ongoing processes depend on the type, length, and severity of podocyte injury, as well as on the ability of parietal epithelial cells to drive repair. In this review, we discuss the main pathology patterns of podocytopathies with a focus on the cellular and molecular response of podocytes and parietal epithelial cells.
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Affiliation(s)
| | - Maria Elena Melica
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, Florence, Italy
| | - Maria Lucia Angelotti
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, Florence, Italy
| | - Letizia De Chiara
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, Florence, Italy
| | - Paola Romagnani
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, Florence, Italy
- Nephrology Unit, Meyer Children’s Hospital, Florence, Italy
| | - Laura Lasagni
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, Florence, Italy
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13
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Shaw L, Sugden CJ, Hamill KJ. Laminin Polymerization and Inherited Disease: Lessons From Genetics. Front Genet 2021; 12:707087. [PMID: 34456976 PMCID: PMC8388930 DOI: 10.3389/fgene.2021.707087] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 07/13/2021] [Indexed: 01/13/2023] Open
Abstract
The laminins (LM) are a family of basement membranes glycoproteins with essential structural roles in supporting epithelia, endothelia, nerves and muscle adhesion, and signaling roles in regulating cell migration, proliferation, stem cell maintenance and differentiation. Laminins are obligate heterotrimers comprised of α, β and γ chains that assemble intracellularly. However, extracellularly these heterotrimers then assemble into higher-order networks via interaction between their laminin N-terminal (LN) domains. In vitro protein studies have identified assembly kinetics and the structural motifs involved in binding of adjacent LN domains. The physiological importance of these interactions has been identified through the study of pathogenic point mutations in LN domains that lead to syndromic disorders presenting with phenotypes dependent on which laminin gene is mutated. Genotype-phenotype comparison between knockout and LN domain missense mutations of the same laminin allows inferences to be drawn about the roles of laminin network assembly in terms of tissue function. In this review, we will discuss these comparisons in terms of laminin disorders, and the therapeutic options that understanding these processes have allowed. We will also discuss recent findings of non-laminin mediators of laminin network assembly and their implications in terms of basement membrane structure and function.
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Affiliation(s)
| | | | - Kevin J. Hamill
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
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14
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Chen D, Liu Y, Chen J, Lin H, Guo H, Wu Y, Xu Y, Zhou Y, Zhou W, Lu R, Zhou J, Wu J. JAK/STAT pathway promotes the progression of diabetic kidney disease via autophagy in podocytes. Eur J Pharmacol 2021; 902:174121. [PMID: 33901462 DOI: 10.1016/j.ejphar.2021.174121] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/13/2021] [Accepted: 04/20/2021] [Indexed: 12/14/2022]
Abstract
Diabetic kidney disease (DKD) is one of the major microvascular complications of diabetes and an important cause of end-stage renal disease. Previous studies have shown that the damage to podocyte autophagy is related to the pathogenesis of DKD, and this damage is closely mediated by the Janus kinase (JAK)/signal transductors and the transcription (STAT) signaling pathway. Here, the underlying molecular mechanism of the JAK/STAT signaling pathway regulating podocyte autophagy was investigated. In the present study, compared to controls, DKD mice showed glomerular hypertrophy, increased kidney weight/weight ratio, and increased urinary protein levels, as well as decreased desmin and synaptopodin expression. Meanwhile, levels of triglyceride, total cholesterol, reduced glutathione, and malondialdehyde were also increased in the serum of DKD mice. Further, a lower number of autophagosomes, reduced expression of MAP1LC3 (LC3) in glomeruli, and increased expression of JAK/STAT pathway-related proteins, namely JAK1, JAK2, STAT1, STAT3, STAT5, and STAT6, were observed in DKD mice. In the in vitro experiments, we observed impaired autophagy, enhanced apoptosis, and activated JAK/STAT pathway in podocytes under high glucose conditions. Studies using ruxolitinib inhibitors have showed that suppression of the JAK/STAT pathway in podocytes subjected to high glucose could increase autophagic flux and autophagy-related protein expression. Taken together, the present study demonstrates that high glucose inhibits autophagy by activating the JAK/STAT pathway in mice and podocytes, thereby preventing the efficient removal of damaged proteins and organelles from the body to prevent apoptosis, and ultimately aggravating the progression of podocyte injury and DKD.
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Affiliation(s)
- Dandan Chen
- Department of Clinical Pharmacy, The Second Aliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China
| | - Yaoyu Liu
- Department of Clinical Pharmacy, The Second Aliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China
| | - Junqi Chen
- Department of Pharmacology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China
| | - Hua Lin
- Department of Clinical Pharmacy, The Second Aliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China
| | - Huijuan Guo
- Department of Pharmacy, Baoan Women's and Children's Hospital, Jinan University, Shenzhen, Guangdong, PR China
| | - Yifan Wu
- Department of Nephrology, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China
| | - Yuan Xu
- Department of Nephrology, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China
| | - Yuan Zhou
- Department of Pharmacology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China
| | - Wei Zhou
- Department of Clinical Pharmacy, The Second Aliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China
| | - Ruirui Lu
- Department of Pharmacology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China
| | - Jiuyao Zhou
- Department of Pharmacology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China.
| | - Junbiao Wu
- Department of Clinical Pharmacy, The Second Aliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, PR China.
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15
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Goddi A, Schroedl L, Brey EM, Cohen RN. Laminins in metabolic tissues. Metabolism 2021; 120:154775. [PMID: 33857525 DOI: 10.1016/j.metabol.2021.154775] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/13/2021] [Accepted: 04/08/2021] [Indexed: 12/16/2022]
Abstract
Laminins are extracellular matrix proteins that reside in the basement membrane and provide structural support in addition to promoting cellular adhesion and migration. Through interactions with cell surface receptors, laminins stimulate intracellular signaling cascades which direct specific survival and differentiation outcomes. In metabolic tissues such as the pancreas, adipose, muscle, and liver, laminin isoforms are expressed in discrete temporal and spatial patterns suggesting that certain isoforms may support the development and function of particular metabolic cell types. This review focuses on the research to date detailing the expression of laminin isoforms, their potential function, as well as known pathways involved in laminin signaling in metabolic tissues. We will also discuss the current biomedical therapies involving laminins in these tissues in addition to prospective applications, with the goal being to encourage future investigation of laminins in the context of metabolic disease.
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Affiliation(s)
- Anna Goddi
- Committee on Molecular Metabolism and Nutrition, The University of Chicago, 900 East 57th St, Chicago, IL 60637, USA
| | - Liesl Schroedl
- Pritzker School of Medicine, The University of Chicago, 924 E 57th St, Chicago, IL 60637, USA
| | - Eric M Brey
- Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
| | - Ronald N Cohen
- Committee on Molecular Metabolism and Nutrition, The University of Chicago, 900 East 57th St, Chicago, IL 60637, USA; Section of Endocrinology, Diabetes, and Metabolism, The University of Chicago, 5841 South Maryland Ave, Chicago, IL 60637, USA.
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16
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17
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Sobieszczańska-Droździel A, Grenda R, Lipska-Ziętkiewicz BS, Korolczuk A, Jarmużek W, Sikora P. Five-Year Follow-Up and Successful Kidney Transplantation in a Girl with a Severe Phenotype of Pierson Syndrome. Nephron Clin Pract 2021; 145:579-584. [PMID: 34058744 DOI: 10.1159/000516247] [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: 10/20/2020] [Accepted: 03/22/2021] [Indexed: 11/19/2022] Open
Abstract
Pierson syndrome (PIERSS) is a rare autosomal recessive disorder characterized by the combination of congenital nephrotic syndrome (CNS) and extrarenal symptoms including ocular malformations and neurodevelopmental deficits. PIERSS is caused by biallelic pathogenic variants in the LAMB2 gene leading to the defects of β2-laminin, the protein mainly expressed in the glomerular basement membrane, ocular structures, and neuromuscular junctions. Severe complications of PIERSS lead to the fatal outcome in early childhood in majority of the cases. We report a case of 5-year-old girl with severe phenotype of PIERSS caused by biallelic functional null variants of the LAMB2 gene. Due to consequences of CNS, the patient required bilateral nephrectomy and peritoneal dialysis since early infancy. The course was additionally complicated by tubulopathy, life-threatening infections, severe hypertension, erythropoietin-resistant anemia, generalized muscular hypotonia, neurogenic bladder, profound neurodevelopmental delay, epilepsy, gastrointestinal problems, secondary hypothyroidism, and necessity of repeated ocular surgery due to microcoria, cataract, and nystagmus. Due to multidisciplinary efforts, at the age of 4 years, the kidney transplantation was possible. Currently, the renal graft has an excellent function; however, the girl presents severe neurodevelopmental delay. The report presents a unique long-term follow-up of severe PIERSS with a few new phenotypical findings. It highlights the clinical problems and challenges in management of this rare condition.
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Affiliation(s)
| | - Ryszard Grenda
- Department of Nephrology, Kidney Transplantation and Hypertension, Children's Memorial Health Institute, Warsaw, Poland
| | - Beata Stefania Lipska-Ziętkiewicz
- Centre for Rare Diseases, Medical University of Gdansk, Gdańsk, Poland.,Department of Biology and Medical Genetics, Clinical Genetics Unit, Medical University of Gdansk, Gdańsk, Poland
| | - Agnieszka Korolczuk
- Department of Clinical Pathomorphology, Medical University of Lublin, Lublin, Poland
| | - Wioletta Jarmużek
- Department of Nephrology, Kidney Transplantation and Hypertension, Children's Memorial Health Institute, Warsaw, Poland
| | - Przemyslaw Sikora
- Department of Pediatric Nephrology, Medical University of Lublin, Lublin, Poland
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18
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Ning L, Suleiman HY, Miner JH. Synaptopodin deficiency exacerbates kidney disease in a mouse model of Alport syndrome. Am J Physiol Renal Physiol 2021; 321:F12-F25. [PMID: 34029143 DOI: 10.1152/ajprenal.00035.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Synaptopodin (Synpo) is an actin-associated protein in podocyte foot processes. By generating mice that completely lack Synpo, we previously showed that Synpo is dispensable for normal kidney function. However, lack of Synpo worsened adriamycin-induced nephropathy, indicating a protective role for Synpo in injured podocytes. Here, we investigated whether lack of Synpo directly impacts a genetic disease, Alport syndrome (AS), because Synpo is reduced in podocytes of affected humans and mice; whether this is merely an association or pathogenic is unknown. We used collagen type IV-α5 (Col4a5) mutant mice, which model X-linked AS, showing glomerular basement membrane (GBM) abnormalities, eventual foot process effacement, and progression to end-stage kidney disease. We intercrossed mice carrying mutations in Synpo and Col4a5 to produce double-mutant mice. Urine and tissue were taken at select time points to evaluate albuminuria, histopathology, and glomerular capillary wall composition and ultrastructure. Lack of Synpo in Col4a5-/Y, Col4a5-/-, or Col4a5+/- Alport mice led to the acceleration of disease progression, including more severe proteinuria and glomerulosclerosis. Absence of Synpo attenuated the shift of myosin IIA from the podocyte cell body and major processes to actin cables near the GBM in the areas of effacement. We speculate that this is mechanistically associated with enhanced loss of podocytes due to easier detachment from the GBM. We conclude that Synpo deletion exacerbates the disease phenotype in Alport mice, revealing the podocyte actin cytoskeleton as a target for therapy in patients with AS.NEW & NOTEWORTHY Alport syndrome (AS) is a hereditary disease of the glomerular basement with hematuria and proteinuria. Podocytes eventually exhibit foot process effacement, indicating actin cytoskeletal changes. To investigate how cytoskeletal changes impact podocytes, we generated Alport mice lacking synaptopodin, an actin-binding protein in foot processes. Analysis showed a more rapid disease progression, demonstrating that synaptopodin is protective. This suggests that the actin cytoskeleton is a target for therapy in AS and perhaps other glomerular diseases.
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Affiliation(s)
- Liang Ning
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Hani Y Suleiman
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - 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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Pokidysheva EN, Seeger H, Pedchenko V, Chetyrkin S, Bergmann C, Abrahamson D, Cui ZW, Delpire E, Fervenza FC, Fidler AL, Fogo AB, Gaspert A, Grohmann M, Gross O, Haddad G, Harris RC, Kashtan C, Kitching AR, Lorenzen JM, McAdoo S, Pusey CD, Segelmark M, Simmons A, Voziyan PA, Wagner T, Wüthrich RP, Zhao MH, Boudko SP, Kistler AD, Hudson BG. Collagen IV α345 dysfunction in glomerular basement membrane diseases. I. Discovery of a COL4A3 variant in familial Goodpasture's and Alport diseases. J Biol Chem 2021; 296:100590. [PMID: 33774048 PMCID: PMC8100070 DOI: 10.1016/j.jbc.2021.100590] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/11/2021] [Accepted: 03/24/2021] [Indexed: 02/06/2023] Open
Abstract
Diseases of the glomerular basement membrane (GBM), such as Goodpasture’s disease (GP) and Alport syndrome (AS), are a major cause of chronic kidney failure and an unmet medical need. Collagen IVα345 is an important architectural element of the GBM that was discovered in previous research on GP and AS. How this collagen enables GBM to function as a permselective filter and how structural defects cause renal failure remain an enigma. We found a distinctive genetic variant of collagen IVα345 in both a familial GP case and four AS kindreds that provided insights into these mechanisms. The variant is an 8-residue appendage at the C-terminus of the α3 subunit of the α345 hexamer. A knock-in mouse harboring the variant displayed GBM abnormalities and proteinuria. This pathology phenocopied AS, which pinpointed the α345 hexamer as a focal point in GBM function and dysfunction. Crystallography and assembly studies revealed underlying hexamer mechanisms, as described in Boudko et al. and Pedchenko et al. Bioactive sites on the hexamer surface were identified where pathogenic pathways of GP and AS converge and, potentially, that of diabetic nephropathy (DN). We conclude that the hexamer functions include signaling and organizing macromolecular complexes, which enable GBM assembly and function. Therapeutic modulation or replacement of α345 hexamer could therefore be a potential treatment for GBM diseases, and this knock-in mouse model is suitable for developing gene therapies.
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Affiliation(s)
- Elena N Pokidysheva
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Harald Seeger
- Nephrology Division, University Hospital Zurich, Zurich, Switzerland
| | - Vadim Pedchenko
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Sergei Chetyrkin
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Carsten Bergmann
- Department of Medicine and Nephrology, University Hospital Freiburg, Freiburg, Germany; Medizinische Genetik Mainz, Limbach Genetics, Mainz, Germany
| | - Dale Abrahamson
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Zhao Wei Cui
- Renal Division, Peking University First Hospital, Beijing, PR China
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Fernando C Fervenza
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Aaron L Fidler
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Aspirnaut Program, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Agnes B Fogo
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ariana Gaspert
- Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Maik Grohmann
- Medizinische Genetik Mainz, Limbach Genetics, Mainz, Germany
| | - Oliver Gross
- Clinic of Nephrology and Rheumatology, University Medical Center Goettingen, University of Goettingen, Goettingen, Germany
| | - George Haddad
- Nephrology Division, University Hospital Zurich, Zurich, Switzerland
| | - Raymond C Harris
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Clifford Kashtan
- Division of Pediatric Nephrology, University of Minnesota Medical School and Masonic Children's Hospital, Minneapolis, Minnesota, USA
| | - A Richard Kitching
- Centre for Inflammatory Diseases, Monash University Department Medicine, Nephrology, Monash Health, Clayton, VIC, Australia
| | - Johan M Lorenzen
- Nephrology Division, University Hospital Zurich, Zurich, Switzerland
| | - Stephen McAdoo
- Centre for Inflammatory Disease, Imperial College London, London, UK
| | - Charles D Pusey
- Centre for Inflammatory Disease, Imperial College London, London, UK
| | - Marten Segelmark
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Alicia Simmons
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Aspirnaut Program, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Paul A Voziyan
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Timo Wagner
- Medizinische Genetik Mainz, Limbach Genetics, Mainz, Germany
| | - Rudolf P Wüthrich
- Nephrology Division, University Hospital Zurich, Zurich, Switzerland
| | - Ming-Hui Zhao
- Renal Division, Peking University First Hospital, Beijing, PR China
| | - Sergei P Boudko
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Andreas D Kistler
- Department of Internal Medicine, Kantonsspital Frauenfeld, Frauenfeld, Switzerland
| | - Billy G Hudson
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Aspirnaut Program, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA; Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA; Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee, USA.
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20
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Angelotti ML, Antonelli G, Conte C, Romagnani P. Imaging the kidney: from light to super-resolution microscopy. Nephrol Dial Transplant 2021; 36:19-28. [PMID: 31325314 PMCID: PMC7771978 DOI: 10.1093/ndt/gfz136] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Indexed: 12/13/2022] Open
Abstract
The important achievements in kidney physiological and pathophysiological mechanisms can largely be ascribed to progress in the technology of microscopy. Much of what we know about the architecture of the kidney is based on the fundamental descriptions of anatomic microscopists using light microscopy and later by ultrastructural analysis provided by electron microscopy. These two techniques were used for the first classification systems of kidney diseases and for their constant updates. More recently, a series of novel imaging techniques added the analysis in further dimensions of time and space. Confocal microscopy allowed us to sequentially visualize optical sections along the z-axis and the availability of specific analysis software provided a three-dimensional rendering of thicker tissue specimens. Multiphoton microscopy permitted us to simultaneously investigate kidney function and structure in real time. Fluorescence-lifetime imaging microscopy allowed to study the spatial distribution of metabolites. Super-resolution microscopy increased sensitivity and resolution up to nanoscale levels. With cryo-electron microscopy, researchers could visualize the individual biomolecules at atomic levels directly in the tissues and understand their interaction at subcellular levels. Finally, matrix-assisted laser desorption/ionization imaging mass spectrometry permitted the measuring of hundreds of different molecules at the same time on tissue sections at high resolution. This review provides an overview of available kidney imaging strategies, with a focus on the possible impact of the most recent technical improvements.
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Affiliation(s)
- Maria Lucia Angelotti
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy.,Excellence Centre for Research, Transfer and High Education for the development of DE NOVO Therapies (DENOTHE), Florence, Italy
| | - Giulia Antonelli
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy.,Excellence Centre for Research, Transfer and High Education for the development of DE NOVO Therapies (DENOTHE), Florence, Italy
| | - Carolina Conte
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy.,Excellence Centre for Research, Transfer and High Education for the development of DE NOVO Therapies (DENOTHE), Florence, Italy
| | - Paola Romagnani
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy.,Excellence Centre for Research, Transfer and High Education for the development of DE NOVO Therapies (DENOTHE), Florence, Italy
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21
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Ranjit S, Lanzanò L, Libby AE, Gratton E, Levi M. Advances in fluorescence microscopy techniques to study kidney function. Nat Rev Nephrol 2020; 17:128-144. [PMID: 32948857 DOI: 10.1038/s41581-020-00337-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2020] [Indexed: 02/07/2023]
Abstract
Fluorescence microscopy, in particular immunofluorescence microscopy, has been used extensively for the assessment of kidney function and pathology for both research and diagnostic purposes. The development of confocal microscopy in the 1950s enabled imaging of live cells and intravital imaging of the kidney; however, confocal microscopy is limited by its maximal spatial resolution and depth. More recent advances in fluorescence microscopy techniques have enabled increasingly detailed assessment of kidney structure and provided extraordinary insights into kidney function. For example, nanoscale precise imaging by rapid beam oscillation (nSPIRO) is a super-resolution microscopy technique that was originally developed for functional imaging of kidney microvilli and enables detection of dynamic physiological events in the kidney. A variety of techniques such as fluorescence recovery after photobleaching (FRAP), fluorescence correlation spectroscopy (FCS) and Förster resonance energy transfer (FRET) enable assessment of interaction between proteins. The emergence of other super-resolution techniques, including super-resolution stimulated emission depletion (STED), photoactivated localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM) and structured illumination microscopy (SIM), has enabled functional imaging of cellular and subcellular organelles at ≤50 nm resolution. The deep imaging via emission recovery (DIVER) detector allows deep, label-free and high-sensitivity imaging of second harmonics, enabling assessment of processes such as fibrosis, whereas fluorescence lifetime imaging microscopy (FLIM) enables assessment of metabolic processes.
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Affiliation(s)
- Suman Ranjit
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC, USA. .,Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, CA, USA.
| | - Luca Lanzanò
- Nanoscopy and NIC@IIT, Istituto Italiano di Tecnologia, Genoa, Italy.,Department of Physics and Astronomy "Ettore Majorana", University of Catania, Catania, Italy
| | - Andrew E Libby
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC, USA
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, CA, USA.
| | - Moshe Levi
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC, USA.
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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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Mo X, Li J, Liu Y, Liao X, Tan M, Chen Y, He F, He Y, Li Y, Huang M. Kidney podocyte-associated gene polymorphisms affect tacrolimus concentration in pediatric patients with refractory nephrotic syndrome. THE PHARMACOGENOMICS JOURNAL 2020; 20:543-552. [PMID: 31902946 DOI: 10.1038/s41397-019-0141-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 11/24/2019] [Accepted: 12/16/2019] [Indexed: 12/11/2022]
Abstract
Few studies have investigated the correlation between pharmacogenomics and tacrolimus pharmacokinetics in patients with nephrotic syndrome (NS). This study evaluated the influences of genetic polymorphisms of metabolic enzymes, transporters, and podocyte-associated proteins on tacrolimus concentration in Chinese pediatric patients with refractory NS. A total of 167 pediatric patients with refractory NS were included from July 2013 to December 2017. Age of onset was restricted to <14 years of age. Dose-adjusted tacrolimus trough concentration (C0/D) on the third month was calculated, and 20 single-nucleotide polymorphisms in sixteen genes were genotyped. Age was correlated with tacrolimus C0/D (p = 0.006, r = 0.213). Tacrolimus C0/D was higher in CYP3A5 nonexpressers than in CYP3A5 expressers (p = 0.003). ACTN4 rs62121818, MYH9 rs2239781, CYP3A5*3, and age explained 20.5% interindividual variability of tacrolimus concentration in the total cohort. In CYP3A5 nonexpressers, ACTN4 rs62121818 and MYH9 rs2239781 together explained 14.6% variation of tacrolimus C0/D. MYH9 rs2239781, LAMB2 rs62119873 and age together explained 22.3% variability of tacrolimus level in CYP3A5 expressers. CYP3A5*3 was still an important factor affecting tacrolimus concentration in patients with NS. Podocyte-associated gene polymorphisms, especially ACTN4 rs62121818 and MYH9 rs2239781, were the other most important biomarkers for tacrolimus whole blood levels. Genotyping of CYP3A5, ACTN4, and MYH9 polymorphisms may be helpful for better guiding tacrolimus dosing in pediatric patients with refractory NS.
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Affiliation(s)
- Xiaolan Mo
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China.,Department of Pharmacy, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China
| | - Jiali Li
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yunfeng Liu
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Xin Liao
- Division of nephrology, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China
| | - Mei Tan
- Division of nephrology, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China
| | - Yilu Chen
- Department of Pharmacy, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China
| | - Fan He
- Department of Pharmacy, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China
| | - Yanling He
- Department of Pharmacy, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China.
| | - Yingjie Li
- Division of nephrology, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China.
| | - Min Huang
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China.
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24
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Reynolds BC, Oswald RJA. Diagnostic and Management Challenges in Congenital Nephrotic Syndrome. PEDIATRIC HEALTH MEDICINE AND THERAPEUTICS 2019; 10:157-167. [PMID: 31908565 PMCID: PMC6930517 DOI: 10.2147/phmt.s193684] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/05/2019] [Indexed: 12/21/2022]
Abstract
Congenital Nephrotic Syndrome (CNS) is defined as nephrotic range proteinuria, hypoalbuminaemia and edema in the first three months of life. CNS is most commonly genetic in cause, with international variance in the incidence of causative mutations. Initially defined by the histopathological appearance, increasingly sophisticated and accessible genetic analyses now provide a body of evidence to suggest that there is a disparity between the histological appearance, the genotype of individuals and the severity of the clinical disease. Through the evolution of management approaches CNS has changed from being an invariably fatal condition to one with appreciable ongoing morbidity and mortality but comparably good outcomes to other causes of paediatric end-stage renal disease, especially following transplantation. This review briefly summarises the more commonly recognised genetic mutations leading to CNS, addresses common management decisions, and concludes with potential therapies for the future.
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25
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Funk SD, Bayer RH, Miner JH. Endothelial cell-specific collagen type IV-α 3 expression does not rescue Alport syndrome in Col4a3 -/- mice. Am J Physiol Renal Physiol 2019; 316:F830-F837. [PMID: 30724107 PMCID: PMC6580247 DOI: 10.1152/ajprenal.00556.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/23/2019] [Accepted: 02/04/2019] [Indexed: 01/15/2023] Open
Abstract
The glomerular basement membrane (GBM) is a critical component of the kidney's blood filtration barrier. Alport syndrome, a hereditary disease leading to kidney failure, is caused by the loss or dysfunction of the GBM's major collagen type IV (COL4) isoform α3α4α5. The constituent COL4 α-chains assemble into heterotrimers in the endoplasmic reticulum before secretion into the extracellular space. If any one of the α3-, α4-, or α5-chains is lost due to mutation of one of the genes, then the entire heterotrimer is lost. Patients with Alport syndrome typically have mutations in the X-linked COL4A5 gene or uncommonly have the autosomal recessive form of the disease due to COL4A3 or COL4A4 mutations. Treatment for Alport syndrome is currently limited to angiotensin-converting enzyme inhibition or angiotensin receptor blockers. Experimental approaches in Alport mice have demonstrated that induced expression of COL4A3, either widely or specifically in podocytes of Col4a3-/- mice, can abrogate disease progression even after establishment of the abnormal GBM. While targeting podocytes in vivo for gene therapy is a significant challenge, the more accessible glomerular endothelium could be amenable for mutant gene repair. In the present study, we expressed COL4A3 in Col4a3-/- Alport mice using an endothelial cell-specific inducible transgenic system, but collagen-α3α4α5(IV) was not detected in the GBM or elsewhere, and the Alport phenotype was not rescued. Our results suggest that endothelial cells do not express the Col4a3/a4/a5 genes and should not be viewed as a target for gene therapy.
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Affiliation(s)
- Steven D Funk
- Department of Medicine, Division of Nephrology, Washington University School of Medicine , St. Louis, Missouri
| | - Raymond H Bayer
- Department of Medicine, Division of Nephrology, Washington University School of Medicine , St. Louis, Missouri
| | - Jeffrey H Miner
- Department of Medicine, Division of Nephrology, Washington University School of Medicine , St. Louis, Missouri
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26
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Müller T, Kalea AZ, Marquez A, Hsieh I, Haque S, Ye M, Wysocki J, Bader M, Batlle D. Apelinergic system in the kidney: implications for diabetic kidney disease. Physiol Rep 2018; 6:e13939. [PMID: 30548130 PMCID: PMC6288480 DOI: 10.14814/phy2.13939] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 11/08/2018] [Accepted: 11/09/2018] [Indexed: 12/19/2022] Open
Abstract
The bioactive peptides of the apelinergic system and its receptor APJ have been shown to play a protective role in experimental cardiovascular and diabetic kidney disease (DKD). Mechanisms of this renoprotective effect remain to be elucidated. In this study, we examined the localization of APJ within the normal kidney and its kidney expression in the db/db model of DKD. The effect of hyperglycemia and angiotensin II on APJ was examined in cultured podocytes. In the glomerulus, APJ colocalized with podocyte but not endothelial cell markers. In podocytes stimulated with Pyr1 Apelin-13, a change in the phosphorylation status of the signaling proteins, AKT, ERK, and p70S6K, was observed with an increase 15 min after stimulation. Apelin-13 decreased activity of Caspase-3 in podocytes after high glucose treatment reflecting an antiapoptotic effect of APJ stimulation. In podocytes, APJ mRNA was downregulated in high glucose, when compared to normal glucose conditions and exposure to angiotensin II led to a further significant decrease in APJ mRNA. APJ and preproapelin mRNA levels in kidneys from db/db mice were markedly decreased along with decreased tubular APJ protein by western blotting and immunostaining when compared to db/m controls. In conclusion, the apelinergic system is decreased in kidneys from db/db mice. Within the glomerulus, APJ is mainly localized in podocytes and in this cell type its activation by Apelin-13 abolishes the proapoptotic effect of high glucose, suggesting a potential therapeutic role of apelin and emerging agonists with extended half-life for therapy of DKD.
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Affiliation(s)
- Tilman Müller
- Department of MedicineDivision of Nephrology and HypertensionFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
- Charité‐Universitätsmedizin BerlinBerlinGermany
| | - Anastasia Z. Kalea
- Department of MedicineDivision of Nephrology and HypertensionFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
- Institute of Liver and Digestive HealthUniversity College LondonLondonUK
| | - Alonso Marquez
- Department of MedicineDivision of Nephrology and HypertensionFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
| | - Ivy Hsieh
- Department of MedicineDivision of Nephrology and HypertensionFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
| | - Syed Haque
- Department of MedicineDivision of Nephrology and HypertensionFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
| | - Minghao Ye
- Department of MedicineDivision of Nephrology and HypertensionFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
| | - Jan Wysocki
- Department of MedicineDivision of Nephrology and HypertensionFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
| | - Michael Bader
- Charité‐Universitätsmedizin BerlinBerlinGermany
- Max Delbrück Center for Molecular MedicineBerlinGermany
- German Center for Cardiovascular Research (DZHK), partner site BerlinBerlinGermany
- Berlin Institute of Health (BIH)BerlinGermany
- University of LübeckLübeckGermany
| | - Daniel Batlle
- Department of MedicineDivision of Nephrology and HypertensionFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
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27
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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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28
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Siegerist F, Endlich K, Endlich N. Novel Microscopic Techniques for Podocyte Research. Front Endocrinol (Lausanne) 2018; 9:379. [PMID: 30050501 PMCID: PMC6050355 DOI: 10.3389/fendo.2018.00379] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/22/2018] [Indexed: 01/16/2023] Open
Abstract
Together with endothelial cells and the glomerular basement membrane, podocytes form the size-specific filtration barrier of the glomerulus with their interdigitating foot processes. Since glomerulopathies are associated with so-called foot process effacement-a severe change of well-formed foot processes into flat and broadened processes-visualization of the three-dimensional podocyte morphology is a crucial part for diagnosis of nephrotic diseases. However, interdigitating podocyte foot processes are too narrow to be resolved by classic light microscopy due to Ernst Abbe's law making electron microscopy necessary. Although three dimensional electron microscopy approaches like serial block face and focused ion beam scanning electron microscopy and electron tomography allow volumetric reconstruction of podocytes, these techniques are very time-consuming and too specialized for routine use or screening purposes. During the last few years, different super-resolution microscopic techniques were developed to overcome the optical resolution limit enabling new insights into podocyte morphology. Super-resolution microscopy approaches like three dimensional structured illumination microscopy (3D-SIM), stimulated emission depletion microscopy (STED) and localization microscopy [stochastic optical reconstruction microscopy (STORM), photoactivated localization microscopy (PALM)] reach resolutions down to 80-20 nm and can be used to image and further quantify podocyte foot process morphology. Furthermore, in vivo imaging of podocytes is essential to study the behavior of these cells in situ. Therefore, multiphoton laser microscopy was a breakthrough for in vivo studies of podocytes in transgenic animal models like rodents and zebrafish larvae because it allows imaging structures up to several hundred micrometer in depth within the tissue. Additionally, along with multiphoton microscopy, lightsheet microscopy is currently used to visualize larger tissue volumes and therefore image complete glomeruli in their native tissue context. Alongside plain visualization of cellular structures, atomic force microscopy has been used to study the change of mechanical properties of podocytes in diseased states which has been shown to be a culprit in podocyte maintenance. This review discusses recent advances in the field of microscopic imaging and demonstrates their currently used and other possible applications for podocyte research.
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Affiliation(s)
| | | | - Nicole Endlich
- Institute for Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
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29
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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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30
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Martin CE, Jones N. Nephrin Signaling in the Podocyte: An Updated View of Signal Regulation at the Slit Diaphragm and Beyond. Front Endocrinol (Lausanne) 2018; 9:302. [PMID: 29922234 PMCID: PMC5996060 DOI: 10.3389/fendo.2018.00302] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 05/22/2018] [Indexed: 12/11/2022] Open
Abstract
Podocytes are a major component of the glomerular blood filtration barrier, and alterations to the morphology of their unique actin-based foot processes (FP) are a common feature of kidney disease. Adjacent FP are connected by a specialized intercellular junction known as the slit diaphragm (SD), which serves as the ultimate barrier to regulate passage of macromolecules from the blood. While the link between SD dysfunction and reduced filtration selectivity has been recognized for nearly 50 years, our understanding of the underlying molecular circuitry began only 20 years ago, sparked by the identification of NPHS1, encoding the transmembrane protein nephrin. Nephrin not only functions as the core component of the extracellular SD filtration network but also as a signaling scaffold via interactions at its short intracellular region. Phospho-regulation of several conserved tyrosine residues in this region influences signal transduction pathways which control podocyte cell adhesion, shape, and survival, and emerging studies highlight roles for nephrin phospho-dynamics in mechanotransduction and endocytosis. The following review aims to summarize the last 5 years of advancement in our knowledge of how signaling centered at nephrin directs SD barrier formation and function. We further provide insight on promising frontiers in podocyte biology, which have implications for SD signaling in the healthy and diseased kidney.
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