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Ma T, Wang M, Wang S, Hu H, Zhang X, Wang H, Wang G, Jin Y. BMSC derived EVs inhibit colorectal Cancer progression by transporting MAGI2-AS3 or something similar. Cell Signal 2024; 121:111235. [PMID: 38806109 DOI: 10.1016/j.cellsig.2024.111235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 05/16/2024] [Accepted: 05/24/2024] [Indexed: 05/30/2024]
Abstract
In this study, we investigated the molecular mechanisms underlying the impact of extracellular vesicles (EVs) derived from bone marrow stromal cells (BMSCs) on colorectal cancer (CRC) development. The focus was on the role of MAGI2-AS3, delivered by BMSC-EVs, in regulating USP6NL DNA methylation-mediated MYC protein translation modification to promote CDK2 downregulation. Utilizing bioinformatics analysis, we identified significant enrichment of MAGI2-AS3 related to copper-induced cell death in CRC. In vitro experiments demonstrated the downregulation of MAGI2-AS3 in CRC cells, and BMSC-EVs were found to deliver MAGI2-AS3 to inhibit CRC cell proliferation, migration, and invasion. Further exploration revealed that MAGI2-AS3 suppressed MYC protein translation modification by regulating USP6NL DNA methylation, leading to CDK2 downregulation and prevention of colorectal cancer. Overexpression of MYC reversed the functional effects of BMSC-EVs-MAGI2-AS3. In vivo experiments validated the inhibitory impact of BMSC-EVs-MAGI2-AS3 on CRC tumorigenicity by promoting CDK2 downregulation through USP6NL DNA methylation-mediated MYC protein translation modification. Overall, BMSC-EVs-MAGI2-AS3 may serve as a potential intervention to prevent CRC occurrence by modulating key molecular pathways.
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Affiliation(s)
- Tianyi Ma
- Department of Colorectal Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin 150000, China
| | - Meng Wang
- Department of Colorectal Surgery, Zhejiang Cancer Hospital (Affiliated Cancer Hospital of the Chinese Academy of Sciences), Hangzhou 310000, China
| | - Song Wang
- Department of Colorectal Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China
| | - Hanqing Hu
- Department of Colorectal Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin 150000, China
| | - Xin Zhang
- Department of Colorectal Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin 150000, China
| | - Hufei Wang
- Department of Colorectal Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin 150000, China
| | - Guiyu Wang
- Department of Colorectal Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin 150000, China.
| | - Yinghu Jin
- Department of Colorectal Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin 150000, China.
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2
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Rosenblad T, Lindén M, Ambite I, Brandström P, Hansson S, Godaly G. Genetic determinants of renal scarring in children with febrile UTI. Pediatr Nephrol 2024:10.1007/s00467-024-06394-6. [PMID: 38767678 DOI: 10.1007/s00467-024-06394-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 05/22/2024]
Abstract
BACKGROUND Febrile urinary tract infections (UTIs) are among the most severe bacterial infections in infants, in which a subset of patients develops complications. Identifying infants at risk of recurrent infections or kidney damage based on clinical signs is challenging. Previous observations suggest that genetic factors influence UTI outcomes and could serve as predictors of disease severity. In this study, we conducted a nationwide survey of infant genotypes to develop a strategy for infection management based on individual genetic risk. Our aims were to identify genetic susceptibility variants for renal scarring (RS) and genetic host factors predisposing to dilating vesicoureteral reflux (VUR) and recurrent UTIs. METHODS To assess genetic susceptibility, we collected and analyzed DNA from blood using exome genotyping. Disease-associated genetic variants were identified through bioinformatics analysis, including allelic frequency tests and odds ratio calculations. Kidney involvement was defined using dimercaptosuccinic acid (DMSA) scintigraphy. RESULTS In this investigation, a cohort comprising 1087 infants presenting with their first episode of febrile UTI was included. Among this cohort, a subset of 137 infants who underwent DMSA scanning was subjected to gene association analysis. Remarkable genetic distinctions were observed between patients with RS and those exhibiting resolved kidney involvement. Notably, the genetic signature indicative of renal scarring prominently featured mitochondrial genes. CONCLUSIONS In this nationwide study of genetic susceptibility to RS after febrile UTIs in infancy, we identified a profile dominated by mitochondrial polymorphisms. This profile can serve as a predictor of future complications, including RS and recurrent UTIs.
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Affiliation(s)
- Therese Rosenblad
- Section for Pediatric Nephrology, Skåne University Hospital, Lund, Sweden
| | - Magnus Lindén
- Department of Pediatrics, Halland Hospital, Halmstad, Sweden
| | - Ines Ambite
- Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Per Brandström
- Pediatric Uro-Nephrology Centre, Queen Silvia's Children's Hospital, Gothenburg, Sweden
| | - Sverker Hansson
- Pediatric Uro-Nephrology Centre, Queen Silvia's Children's Hospital, Gothenburg, Sweden
- Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Gabriela Godaly
- Department of Laboratory Medicine, Lund University, Lund, Sweden.
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3
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Finn LS. Nephrotic Syndrome Throughout Childhood: Diagnosing Podocytopathies From the Womb to the Dorm. Pediatr Dev Pathol 2024:10935266241242669. [PMID: 38745407 DOI: 10.1177/10935266241242669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The etiologies of podocyte dysfunction that lead to pediatric nephrotic syndrome (NS) are vast and vary with age at presentation. The discovery of numerous novel genetic podocytopathies and the evolution of diagnostic technologies has transformed the investigation of steroid-resistant NS while simultaneously promoting the replacement of traditional morphology-based disease classifications with a mechanistic approach. Podocytopathies associated with primary and secondary steroid-resistant NS manifest as diffuse mesangial sclerosis, minimal change disease, focal segmental glomerulosclerosis, and collapsing glomerulopathy. Molecular testing, once an ancillary option, has become a vital component of the clinical investigation and when paired with kidney biopsy findings, provides data that can optimize treatment and prognosis. This review focuses on the causes including selected monogenic defects, clinical phenotypes, histopathologic findings, and age-appropriate differential diagnoses of nephrotic syndrome in the pediatric population with an emphasis on podocytopathies.
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Affiliation(s)
- Laura S Finn
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at The University of Pennsylvania, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
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4
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Yufang W, Mingfang L, Nan H, Tingting W. Quercetin-targeted AKT1 regulates the Raf/MEK/ERK signaling pathway to protect against doxorubicin-induced nephropathy in mice. Tissue Cell 2023; 85:102229. [PMID: 37812949 DOI: 10.1016/j.tice.2023.102229] [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: 06/07/2023] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/11/2023]
Abstract
BACKGROUND Doxorubicin is an anthracycline antitumor agent commonly used in clinical practice, which has some nephrotoxicity and is often used to establish mouse models of kidney injury for basic medical research. This study will investigate the protective effect of quercetin on renal function in doxorubicin-induced nephropathy mice. METHODS C57BL/6 mice were divided into control, model, and quercetin low-, and high-dose groups. Serum and urine were collected to analyze markers of kidney function. H&E staining was used to detect pathological changes in renal tissues. Transmission electron microscopy was performed to observe the ultrastructural changes in renal tissues. Immunohistochemistry was performed to detect the changes of Ang II. RT-qPCR was performed to detect the changes of cytokines. ELISA was used to detect changes in serum inflammatory factors. Molecular docking was performed to verify the targeting relationship between quercetin and AKT1. Western blot was performed to detect Bax, Bcl-2, Cyt-c, AKT1, Raf, MEK, and ERK proteins. RESULTS Quercetin could induce the recovery of kidney function in kidney-injured mice; H&E results showed that kidney tissue damage and tissue fibrosis were reduced in kidney-injured mice under quercetin. The mitochondrial swollen structure was destroyed by doxorubicin, while the mitochondrial structure was restored under quercetin. The levels of abnormal apoptotic proteins Bax and Bcl-2 were regulated to normal by quercetin. The high expression of Ang II caused by doxorubicin was down-regulated by quercetin. Abnormal inflammatory factors caused by doxorubicin were reversed by quercetin. Western blot experiments showed that quercetin regulated the protein levels of AKT1 and Raf/MEK/ERK and inhibited the detrimental effects of doxorubicin. CONCLUSION Quercetin may mitigate doxorubicin-induced kidney injury in mice by regulating renal cell inflammatory factors and Raf/MEK/ERK signaling pathway through AKT1 to promote recovery of renal function.
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Affiliation(s)
- Wang Yufang
- Department of Medical Laboratory Diagnosis Lecturer, Quanzhou Medical College, Quanzhou, Fujian Province, China.
| | - Liu Mingfang
- The Second Attached Hospital of Fujian Medical University, Quanzhou, Fujian Province, China
| | - Huang Nan
- Department of Medical Laboratory Diagnosis Lecturer, Quanzhou Medical College, Quanzhou, Fujian Province, China
| | - Wang Tingting
- Department of Medical Laboratory Diagnosis Lecturer, Quanzhou Medical College, Quanzhou, Fujian Province, China
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5
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Wang T, Li C, Wang X, Liu F. MAGI2 ameliorates podocyte apoptosis of diabetic kidney disease through communication with TGF-β-Smad3/nephrin pathway. FASEB J 2023; 37:e23305. [PMID: 37950637 DOI: 10.1096/fj.202301058r] [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: 05/27/2023] [Revised: 09/15/2023] [Accepted: 10/27/2023] [Indexed: 11/13/2023]
Abstract
Podocytes, the key component of the glomerular filtration barrier (GFB), are gradually lost during the progression of diabetic kidney disease (DKD), severely compromising kidney functionality. The molecular mechanisms regulating the survival of podocytes in DKD are incompletely understood. Here, we show that membrane-associated guanylate kinase inverted 2 (MAGI2) is specifically expressed in renal podocytes, and promotes podocyte survival in DKD. We found that MAGI2 expression was downregulated in podocytes cultured with high-glucose in vitro, and in kidneys of db/db mice as well as DKD patients. Conversely, we found enforced expression of MAGI2 via AAV transduction protected podocytes from apoptosis, with concomitant improvement of renal functions. Mechanistically, we found that MAGI2 deficiency induced by high glucose levels activates TGF-β signaling to decrease the expression of anti-apoptotic proteins. These results indicate that MAGI2 protects podocytes from cell death, and can be harnessed therapeutically to improve renal function in diabetic kidney disease.
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Affiliation(s)
- Tingli Wang
- Department of Nephrology, Kidney Research Institute, West China Hospital, Sichuan University, Chengdu, China
| | - Chen Li
- Centre for Translational Research in Cancer, Sichuan Cancer Hospital & Institute, School of medicine, University of Electronic Science and Technology of China, Chengdu, China
- West China Hospital, Sichuan University, Chengdu, China
| | - Xiaofei Wang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Fang Liu
- Department of Nephrology, Kidney Research Institute, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Diabetic Kidney Disease, Centre of Diabetes and Metabolism Research, West China Hospital, Sichuan University, Chengdu, China
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6
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Marcos González S, Rodrigo Calabia E, Varela I, Červienka M, Freire Salinas J, Gómez Román JJ. High Rate of Mutations of Adhesion Molecules and Extracellular Matrix Glycoproteins in Patients with Adult-Onset Focal and Segmental Glomerulosclerosis. Biomedicines 2023; 11:1764. [PMID: 37371859 DOI: 10.3390/biomedicines11061764] [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: 05/11/2023] [Revised: 06/15/2023] [Accepted: 06/18/2023] [Indexed: 06/29/2023] Open
Abstract
(1) Background: Focal and segmental glomerulosclerosis (FSGS) is a pattern of injury that results from podocyte loss in the setting of a wide variety of injurious mechanisms. These include both acquired and genetic as well as primary and secondary causes, or a combination thereof, without optimal therapy, and a high rate of patients develop end-stage renal disease (ESRD). Genetic studies have helped improve the global understanding of FSGS syndrome; thus, we hypothesize that patients with primary FSGS may have underlying alterations in adhesion molecules or extracellular matrix glycoproteins related to previously unreported mutations that may be studied through next-generation sequencing (NGS). (2) Methods: We developed an NGS panel with 29 genes related to adhesion and extracellular matrix glycoproteins. DNA was extracted from twenty-three FSGS patients diagnosed by renal biopsy; (3) Results: The average number of accumulated variants in FSGS patients was high. We describe the missense variant ITGB3c.1199G>A, which is considered pathogenic; in addition, we discovered the nonsense variant CDH1c.499G>T, which lacks a Reference SNP (rs) Report and is considered likely pathogenic. (4) Conclusions: To the best of our knowledge, this is the first account of a high rate of change in extracellular matrix glycoproteins and adhesion molecules in individuals with adult-onset FSGS. The combined effect of all these variations may result in a genotype that is vulnerable to the pathogenesis of glomerulopathy.
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Affiliation(s)
- Sara Marcos González
- Pathology Department, Marqués de Valdecilla University Hospital, Institute of Research Valdecilla (IDIVAL), 39008 Santander, Spain
| | - Emilio Rodrigo Calabia
- Nephrology Department, Marqués de Valdecilla University Hospital, 39008, University of Cantabria, 39005 Santander, Spain
| | - Ignacio Varela
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), 39011, University of Cantabria-CSIC, 39005 Santander, Spain
| | - Michal Červienka
- Nephrology Department, Rio Carrion General Hospital, 34005 Palencia, Spain
| | - Javier Freire Salinas
- Anatomic Pathology, Marqués de Valdecilla University Hospital, Institute of Research Valdecilla (IDIVAL), 39008 Santander, Spain
| | - José Javier Gómez Román
- Pathology Department, Marqués de Valdecilla University Hospital, Institute of Research Valdecilla (IDIVAL), School of Medicine, University of Cantabria, 39008 Santander, Spain
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7
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Gerlach GF, Imseis ZH, Cooper SL, Santos AN, O’Brien LL. Mapping of the podocin proximity-dependent proteome reveals novel components of the kidney podocyte foot process. Front Cell Dev Biol 2023; 11:1195037. [PMID: 37325559 PMCID: PMC10262054 DOI: 10.3389/fcell.2023.1195037] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 05/03/2023] [Indexed: 06/17/2023] Open
Abstract
Introduction: The unique architecture of glomerular podocytes is integral to kidney filtration. Interdigitating foot processes extend from the podocyte cell body, wrap around fenestrated capillaries, and form specialized junctional complexes termed slit diaphragms to create a molecular sieve. However, the full complement of proteins which maintain foot process integrity, and how this localized proteome changes with disease, remain to be elucidated. Methods: Proximity-dependent biotin identification (BioID) enables the identification of spatially localized proteomes. To this end, we developed a novel in vivo BioID knock-in mouse model. We utilized the slit diaphragm protein podocin (Nphs2) to create a podocin-BioID fusion. Podocin-BioID localizes to the slit diaphragm, and biotin injection leads to podocyte-specific protein biotinylation. We isolated the biotinylated proteins and performed mass spectrometry to identify proximal interactors. Results and Discussion: Gene ontology analysis of 54 proteins specifically enriched in our podocin-BioID sample revealed 'cell junctions,' 'actin binding,' and 'cytoskeleton organization' as top terms. Known foot process components were identified, and we further uncovered two novel proteins: the tricellular junctional protein Ildr2 and the CDC42 and N-WASP interactor Fnbp1l. We confirmed that Ildr2 and Fnbp1l are expressed by podocytes and partially colocalize with podocin. Finally, we investigated how this proteome changes with age and uncovered a significant increase in Ildr2. This was confirmed by immunofluorescence on human kidney samples and suggests altered junctional composition may preserve podocyte integrity. Together, these assays have led to new insights into podocyte biology and support the efficacy of utilizing BioID in vivo to interrogate spatially localized proteomes in health, aging, and disease.
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Affiliation(s)
| | | | | | | | - Lori L. O’Brien
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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8
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Zhang M, Cao A, Lin L, Chen Y, Shang Y, Wang C, Zhang M, Zhu J. Phosphorylation-dependent recognition of diverse protein targets by the cryptic GK domain of MAGI MAGUKs. SCIENCE ADVANCES 2023; 9:eadf3295. [PMID: 37163606 PMCID: PMC10171801 DOI: 10.1126/sciadv.adf3295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Dynamic signal transduction requires the rapid assembly and disassembly of signaling complexes, often mediated by phosphoprotein binding modules. The guanylate kinase-like (GK) domain of the membrane-associated guanylate kinases (MAGUKs) is such a module orchestrating signaling at cellular junctions. The MAGI subfamily of MAGUKs contains a truncated GK domain with unknown structure and function, although they participate in diverse physiological and pathological processes. Here, we demonstrate that the truncated GK domain of MAGI2 interacts with its adjacent PDZ0 domain to form a structural supramodule capable of recognizing phosphoproteins. A conserved phosphorylation-dependent binding motif for PDZ0-GK is delineated, which leads to identification of a set of previously unknown binding partners. We explore the structure and function of the MAGI2-target complex with an inhibitory peptide derived from the consensus motif. Our work reveals an action mechanism of the cryptic MAGI GKs and broadens our understanding of the target recognition rules of phosphoprotein binding modules.
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Affiliation(s)
- Meng Zhang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
- Department of Neurology, the First Affiliated Hospital of USTC, Ministry of Education Key Laboratory for Cellular Dynamics, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Aili Cao
- Department of Nephrology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Lin Lin
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ying Chen
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Yuan Shang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Chao Wang
- Department of Neurology, the First Affiliated Hospital of USTC, Ministry of Education Key Laboratory for Cellular Dynamics, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Mingjie Zhang
- School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jinwei Zhu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
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9
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Morito N, Usui T, Ishibashi S, Yamagata K. Podocyte-specific Transcription Factors: Could MafB Become a Therapeutic Target for Kidney Disease? Intern Med 2023; 62:11-19. [PMID: 35249929 PMCID: PMC9876710 DOI: 10.2169/internalmedicine.9336-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The increasing number of patients with chronic kidney disease (CKD) is being recognized as an emerging global health problem. Recently, it has become clear that injury and loss of glomerular visceral epithelial cells, known as podocytes, is a common early event in many forms of CKD. Podocytes are highly specialized epithelial cells that cover the outer layer of the glomerular basement membrane. They serve as the final barrier to urinary protein loss through the formation and maintenance of specialized foot-processes and an interposed slit-diaphragm. We previously reported that the transcription factor MafB regulates the podocyte slit diaphragm protein production and transcription factor Tcf21. We showed that the forced expression of MafB was able to prevent CKD. In this review, we discuss recent advances and offer an updated overview of the functions of podocyte-specific transcription factors in kidney biology, aiming to present new perspectives on the progression of CKD and respective therapeutic strategies.
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Affiliation(s)
- Naoki Morito
- Department of Nephrology, Faculty of Medicine, University of Tsukuba, Japan
| | - Toshiaki Usui
- Department of Nephrology, Faculty of Medicine, University of Tsukuba, Japan
| | - Shun Ishibashi
- Department of Nephrology, Faculty of Medicine, University of Tsukuba, Japan
| | - Kunihiro Yamagata
- Department of Nephrology, Faculty of Medicine, University of Tsukuba, Japan
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10
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Bierzynska A, Bull K, Miellet S, Dean P, Neal C, Colby E, McCarthy HJ, Hegde S, Sinha MD, Bugarin Diz C, Stirrups K, Megy K, Mapeta R, Penkett C, Marsh S, Forrester N, Afzal M, Stark H, BioResource NIHR, Williams M, Welsh GI, Koziell AB, Hartley PS, Saleem MA. Exploring the relevance of NUP93 variants in steroid-resistant nephrotic syndrome using next generation sequencing and a fly kidney model. Pediatr Nephrol 2022; 37:2643-2656. [PMID: 35211795 PMCID: PMC9489583 DOI: 10.1007/s00467-022-05440-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 12/10/2021] [Accepted: 12/21/2021] [Indexed: 10/24/2022]
Abstract
BACKGROUND Variants in genes encoding nuclear pore complex (NPC) proteins are a newly identified cause of paediatric steroid-resistant nephrotic syndrome (SRNS). Recent reports describing NUP93 variants suggest these could be a significant cause of paediatric onset SRNS. We report NUP93 cases in the UK and demonstrate in vivo functional effects of Nup93 depletion in a fly (Drosophila melanogaster) nephrocyte model. METHODS Three hundred thirty-seven paediatric SRNS patients from the National cohort of patients with Nephrotic Syndrome (NephroS) were whole exome and/or whole genome sequenced. Patients were screened for over 70 genes known to be associated with Nephrotic Syndrome (NS). D. melanogaster Nup93 knockdown was achieved by RNA interference using nephrocyte-restricted drivers. RESULTS Six novel homozygous and compound heterozygous NUP93 variants were detected in 3 sporadic and 2 familial paediatric onset SRNS characterised histologically by focal segmental glomerulosclerosis (FSGS) and progressing to kidney failure by 12 months from clinical diagnosis. Silencing of the two orthologs of human NUP93 expressed in D. melanogaster, Nup93-1, and Nup93-2 resulted in significant signal reduction of up to 82% in adult pericardial nephrocytes with concomitant disruption of NPC protein expression. Additionally, nephrocyte morphology was highly abnormal in Nup93-1 and Nup93-2 silenced flies surviving to adulthood. CONCLUSION We expand the spectrum of NUP93 variants detected in paediatric onset SRNS and demonstrate its incidence within a national cohort. Silencing of either D. melanogaster Nup93 ortholog caused a severe nephrocyte phenotype, signaling an important role for the nucleoporin complex in podocyte biology. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Agnieszka Bierzynska
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Katherine Bull
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sara Miellet
- Department of Life and Environmental Science, Bournemouth University, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB England, UK
- Illawarra Health and Medical Research Institute, Molecular Horizons and School of Medicine, University of Wollongong, Wollongong, Australia
| | - Philip Dean
- Bristol Genetics Laboratory, North Bristol National Health Service Trust, Bristol, UK
| | - Chris Neal
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Elizabeth Colby
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Hugh J. McCarthy
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
- School of Medicine, University of Sydney and Children’s Hospital at Westmead, Westmead, Australia
| | - Shivaram Hegde
- Children’s Kidney Centre, University Hospital of Wales, Cardiff, UK
| | - Manish D. Sinha
- Department of Paediatric Nephrology, Evelina London Children’s Hospital, Guy’s and St, Thomas’ Hospital, London, UK
| | - Carmen Bugarin Diz
- School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King’s College London, London, SE1 7EH UK
| | - Kathleen Stirrups
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - Karyn Megy
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Rutendo Mapeta
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Chris Penkett
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - Sarah Marsh
- Bristol Genetics Laboratory, North Bristol National Health Service Trust, Bristol, UK
| | - Natalie Forrester
- Illawarra Health and Medical Research Institute, Molecular Horizons and School of Medicine, University of Wollongong, Wollongong, Australia
| | - Maryam Afzal
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Hannah Stark
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - NIHR BioResource
- NIHR BioResource, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, CB2 0QQ UK
| | - Maggie Williams
- Bristol Genetics Laboratory, North Bristol National Health Service Trust, Bristol, UK
| | - Gavin I. Welsh
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
| | - Ania B. Koziell
- Department of Paediatric Nephrology, Evelina London Children’s Hospital, Guy’s and St, Thomas’ Hospital, London, UK
- School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King’s College London, London, SE1 7EH UK
| | - Paul S. Hartley
- Department of Life and Environmental Science, Bournemouth University, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB England, UK
| | - Moin A. Saleem
- Bristol Renal and Children’s Renal Unit, Bristol Medical School, University of Bristol, Whitson Street, Bristol, BS1 3NY UK
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11
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Excoffon KJDA, Avila CL, Alghamri MS, Kolawole AO. The magic of MAGI-1: A scaffolding protein with multi signalosomes and functional plasticity. Biol Cell 2022; 114:185-198. [PMID: 35389514 DOI: 10.1111/boc.202200014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/01/2022] [Accepted: 04/04/2022] [Indexed: 11/29/2022]
Abstract
MAGI-1 is a critical cellular scaffolding protein with over 110 different cellular and microbial protein interactors. Since the discovery of MAGI-1 in 1997, MAGI-1 has been implicated in diverse cellular functions such as polarity, cell-cell communication, neurological processes, kidney function, and a host of diseases including cancer and microbial infection. Additionally, MAGI-1 has undergone nomenclature changes in response to the discovery of an additional PDZ domain, leading to lack of continuity in the literature. We address the nomenclature of MAGI-1 as well as summarize many of the critical functions of the known interactions. Given the importance of many of the interactors, such as human papillomavirus E6, the Coxsackievirus and adenovirus receptor (CAR), and PTEN, the enhancement or disruption of MAGI-based interactions has the potential to affect cellular functions that can potentially be harnessed as a therapeutic strategy for a variety of diseases.
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Affiliation(s)
| | - Christina L Avila
- Department of Biological Sciences, Wright State University, Dayton, Ohio, USA
| | - Mahmoud S Alghamri
- Department of Biological Sciences, Wright State University, Dayton, Ohio, USA
| | - Abimbola O Kolawole
- Department of Biological Sciences, Wright State University, Dayton, Ohio, USA
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12
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Xiao M, Bohnert BN, Grahammer F, Artunc F. Rodent models to study sodium retention in experimental nephrotic syndrome. Acta Physiol (Oxf) 2022; 235:e13844. [PMID: 35569011 DOI: 10.1111/apha.13844] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 05/02/2022] [Accepted: 05/10/2022] [Indexed: 12/12/2022]
Abstract
Sodium retention and edema are hallmarks of nephrotic syndrome (NS). Different experimental rodent models have been established for simulating NS, however, not all of them feature sodium retention which requires proteinuria to exceed a certain threshold. In rats, puromycin aminonucleoside nephrosis (PAN) is a classic NS model introduced in 1955 that was adopted as doxorubicin-induced nephropathy (DIN) in 129S1/SvImJ mice. In recent years, mice with inducible podocin deletion (Nphs2Δipod ) or podocyte apoptosis (POD-ATTAC) have been developed. In these models, sodium retention is thought to be caused by activation of the epithelial sodium channel (ENaC) in the distal nephron through aberrantly filtered serine proteases or proteasuria. Strikingly, rodent NS models follow an identical chronological time course after the development of proteinuria featuring sodium retention within days and spontaneous reversal thereafter. In DIN and Nphs2Δipod mice, inhibition of ENaC by amiloride or urinary serine protease activity by aprotinin prevents sodium retention, opening up new and promising therapeutic approaches that could be translated into the treatment of nephrotic patients. However, the essential serine protease(s) responsible for ENaC activation is (are) still unknown. With the use of nephrotic rodent models, there is the possibility that this (these) will be identified in the future. This review summarizes the various rodent models used to study experimental nephrotic syndrome and the insights gained from these models with regard to the pathophysiology of sodium retention.
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Affiliation(s)
- Mengyun Xiao
- Division of Endocrinology, Diabetology and Nephrology, Department of Internal Medicine University Hospital Tübingen Tübingen Germany
| | - Bernhard N. Bohnert
- Division of Endocrinology, Diabetology and Nephrology, Department of Internal Medicine University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
| | - Florian Grahammer
- III. Department of Medicine University Medical Center Hamburg‐Eppendorf Hamburg Germany
| | - Ferruh Artunc
- Division of Endocrinology, Diabetology and Nephrology, Department of Internal Medicine University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
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13
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Mason AE, Saleem MA, Bierzynska A. A critical re-analysis of cases of post-transplantation recurrence in genetic nephrotic syndrome. Pediatr Nephrol 2021; 36:3757-3769. [PMID: 34031708 PMCID: PMC8497325 DOI: 10.1007/s00467-021-05134-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 04/29/2021] [Accepted: 05/12/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Genetic defects in podocyte proteins account for up to 30% of steroid-resistant nephrotic syndrome (SRNS) in the paediatric population. Most children with genetic SRNS are resistant to immunosuppression and at high risk of progression to stage 5 chronic kidney disease. Kidney transplantation is often the treatment of choice. The possibility of post-transplantation disease recurrence in genetic SRNS remains controversial, and poses fundamental questions about disease biology. METHODS We critically evaluated the published cases of post-transplantation recurrence in genetic patients, particularly testing 'mutations' against the most recent population variant databases, in order to clarify the diagnoses, and compare the clinical courses and responses to therapy. RESULTS Biallelic pathogenic variants in NPHS1 leading to a complete absence of nephrin were the most commonly reported and best understood instance of nephrotic syndrome occurring post-transplantation. This is an immune-mediated process driven by antibody production against the novel nephrin protein in the allograft. We also identified a number of plausible reported cases of post-transplantation recurrence involving pathogenic variants in NPHS2 (8 patients, biallelic), one in WT1 (monoallelic) and one in NUP93 (biallelic). However, the mechanism for recurrence in these cases remains unclear. Other instances of recurrence in genetic disease were difficult to interpret due to differing clinical criteria, inclusion of patients without true pathogenic variants or the influence of other factors on renal outcome. CONCLUSIONS Overall, post-transplantation recurrence remains very rare in patients with genetic SRNS. It appears to occur later after transplantation than in other patients and usually responds well to plasmapheresis with a good renal outcome.
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Affiliation(s)
- Anna E Mason
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol, BS1 3NY, UK
| | - Moin A Saleem
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol, BS1 3NY, UK.
| | - Agnieszka Bierzynska
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol, BS1 3NY, UK
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Zarzuelo-Romero MJ, Pérez-Ramírez C, Cura Y, Carrasco-Campos MI, Marangoni-Iglecias LM, Ramírez-Tortosa MC, Jiménez-Morales A. Influence of Genetic Polymorphisms on Clinical Outcomes of Glatiramer Acetate in Multiple Sclerosis Patients. J Pers Med 2021; 11:jpm11101032. [PMID: 34683173 PMCID: PMC8540092 DOI: 10.3390/jpm11101032] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 10/04/2021] [Accepted: 10/05/2021] [Indexed: 02/07/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating disease of autoimmune origin, in which inflammation and demyelination lead to neurodegeneration and progressive disability. Treatment is aimed at slowing down the course of the disease and mitigating its symptoms. One of the first-line treatments used in patients with MS is glatiramer acetate (GA). However, in clinical practice, a response rate of between 30% and 55% is observed. This variability in the effectiveness of the medication may be influenced by genetic factors such as polymorphisms in the genes involved in the pathogenesis of MS. Therefore, this review assesses the impact of genetic variants on the response to GA therapy in patients diagnosed with MS. The results suggest that a relationship exists between the effectiveness of the treatment with GA and the presence of polymorphisms in the following genes: CD86, CLEC16A, CTSS, EOMES, MBP, FAS, TRBC1, IL1R1, IL12RB2, IL22RA2, PTPRT, PVT1, ALOX5AP, MAGI2, ZAK, RFPL3, UVRAG, SLC1A4, and HLA-DRB1*1501. Consequently, the identification of polymorphisms in these genes can be used in the future as a predictive marker of the response to GA treatment in patients diagnosed with MS. Nevertheless, there is a lack of evidence for this and more validation studies need to be conducted to apply this information to clinical practice.
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Affiliation(s)
- María José Zarzuelo-Romero
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Granada, 18001 Granada, Spain;
| | - Cristina Pérez-Ramírez
- Center of Biomedical Research, Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology “José Mataix”, University of Granada, Avda. del Conocimiento s/n., 18016 Armilla, Granada, Spain;
- Pharmacogenetics Unit, Pharmacy Service, Virgen de las Nieves University Hospital, 18012 Granada, Spain; (Y.C.); (M.I.C.-C.); (L.M.M.-I.); (A.J.-M.)
- Correspondence:
| | - Yasmín Cura
- Pharmacogenetics Unit, Pharmacy Service, Virgen de las Nieves University Hospital, 18012 Granada, Spain; (Y.C.); (M.I.C.-C.); (L.M.M.-I.); (A.J.-M.)
| | - María Isabel Carrasco-Campos
- Pharmacogenetics Unit, Pharmacy Service, Virgen de las Nieves University Hospital, 18012 Granada, Spain; (Y.C.); (M.I.C.-C.); (L.M.M.-I.); (A.J.-M.)
| | - Luciana María Marangoni-Iglecias
- Pharmacogenetics Unit, Pharmacy Service, Virgen de las Nieves University Hospital, 18012 Granada, Spain; (Y.C.); (M.I.C.-C.); (L.M.M.-I.); (A.J.-M.)
| | - María Carmen Ramírez-Tortosa
- Center of Biomedical Research, Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology “José Mataix”, University of Granada, Avda. del Conocimiento s/n., 18016 Armilla, Granada, Spain;
| | - Alberto Jiménez-Morales
- Pharmacogenetics Unit, Pharmacy Service, Virgen de las Nieves University Hospital, 18012 Granada, Spain; (Y.C.); (M.I.C.-C.); (L.M.M.-I.); (A.J.-M.)
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He Y, Liu H, Luo S, Amos CI, Lee JE, Li X, Nan H, Wei Q. Genetic variants of SDCCAG8 and MAGI2 in mitosis-related pathway genes are independent predictors of cutaneous melanoma-specific survival. Cancer Sci 2021; 112:4355-4364. [PMID: 34375487 PMCID: PMC8486203 DOI: 10.1111/cas.15102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 12/01/2022] Open
Abstract
Mitosis is a prognostic factor for cutaneous melanoma (CM), but accurate mitosis detection in CM tissues is difficult. Therefore, the 8th Edition of the American Joint Committee on Cancer staging system has removed the mitotic rate as a category criterion of the tumor T-category, based on the evidence that the mitotic rate was not an independent prognostic factor for melanoma survival. As single-nucleotide polymorphisms (SNPs) have been shown to be potential predictors for cutaneous melanoma-specific survival (CMSS), we investigated the potential prognostic value of SNPs in mitosis-related pathway genes in CMSS by analyzing their associations with outcomes of 850 CM patients from The University of Texas MD Anderson Cancer Center in a discovery dataset and validated the findings in another dataset of 409 CM patients from the Harvard University Nurses' Health Study and Health Professionals Follow-up Study. In both datasets, we identified two SNPs (SDCCAG8 rs10803138 G>A and MAGI2 rs3807694 C>T) as independent prognostic factors for CMSS, with adjusted allelic hazards ratios of 1.49 (95% confidence interval = 1.17-1.90, P = .001) and 1.45 (1.13-1.86, P = .003), respectively. Furthermore, their combined unfavorable alleles also predicted a poor survival in both discovery and validation datasets in a dose-response manner (Ptrend = .0006 and .0001, respectively). Additional functional analysis revealed that both SDCCAG8 rs10803138 A and MAGI2 rs3807694 T alleles were associated with elevated mRNA expression levels in normal tissues. Therefore, these findings suggest that SDCCAG8 rs10803138 G>A and MAGI2 rs3807694 C>T are independent prognostic biomarkers for CMSS, possibly by regulating the mRNA expression of the corresponding genes involved in mitosis.
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Affiliation(s)
- Yuanmin He
- Department of DermatologyThe Affiliated Hospital of Southwest Medical UniversityLuzhouChina
- Duke Cancer InstituteDuke University Medical CenterDurhamNCUSA
- Department of Population Health SciencesDuke University School of MedicineDurhamNCUSA
| | - Hongliang Liu
- Duke Cancer InstituteDuke University Medical CenterDurhamNCUSA
- Department of Population Health SciencesDuke University School of MedicineDurhamNCUSA
| | - Sheng Luo
- Department of Biostatistics and BioinformaticsDuke University School of MedicineDurhamNCUSA
| | - Christopher I. Amos
- Institute for Clinical and Translational ResearchBaylor College of MedicineHoustonTXUSA
| | - Jeffrey E. Lee
- Department of Surgical OncologyThe University of Texas M. D. Anderson Cancer CenterHoustonTXUSA
| | - Xin Li
- Department of EpidemiologyRichard M. Fairbanks School of Public HealthIndiana UniversityIndianapolisINUSA
| | - Hongmei Nan
- Department of EpidemiologyRichard M. Fairbanks School of Public HealthIndiana UniversityIndianapolisINUSA
| | - Qingyi Wei
- Duke Cancer InstituteDuke University Medical CenterDurhamNCUSA
- Department of Population Health SciencesDuke University School of MedicineDurhamNCUSA
- Department of MedicineDuke University School of MedicineDurhamNCUSA
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Zhang Y, Zhong Z, Ye J, Wang C. Crystal structure of the PDZ4 domain of MAGI2 in complex with PBM of ARMS reveals a canonical PDZ recognition mode. Neurochem Int 2021; 149:105152. [PMID: 34371146 DOI: 10.1016/j.neuint.2021.105152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 07/07/2021] [Accepted: 08/05/2021] [Indexed: 10/20/2022]
Abstract
Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 2 (MAGI2) is a neuronal scaffold protein that plays critical roles at synaptic junctions by assembling neurotransmitter receptors and cell adhesion proteins through its multiple protein-protein interaction domains, including six PDZ domains, two phosphoserine-phosphothreonine binding WW domains, and a guanylate kinase GK domain. Previous studies showed that MAGI2 participates in formation of tetrameric complexes with PDZ-GEF1, TrkA receptor, and ankyrin repeat-rich membrane spanning (ARMS) protein at late endosomes and is crucial for neurite outgrowth. However, the molecular mechanism governing the assembly of these complexes remains unknown. Here, we characterize the direct interaction between MAGI2 and ARMS through multiple biochemical assays. Moreover, our solved crystal structure of the truncated PDZ4/PBM (PDZ binding motifs) complex of MAGI2 and ARMS proteins (MAGI2-PDZ4/ARMS-PBM) reveals that the binding interface lies between the αB/βB groove from the PDZ4 of MAGI2 and the C-terminal PBM from ARMS. The structure reveals high similarity to others in this protein family where canonical PDZ/PBM interactions are observed. However, the conserved "GLGF" motif in the PSD-95-PDZ3 changes to "GFGF" in the MAGI2-PDZ4/ARMS-PBM complex. We further validated our crystal structure through serial mutagenesis assays. Taken together, our study provides the biochemical details and binding mechanisms that underpin the stabilization of the MAGI2-PDZ4/ARMS-PBM complex, thereby offering a biochemical and structural basis for further understanding of the functional roles of MAGI2, ARMS, PDZ-GEF1, and TrkA in forming the tetrameric receptor complex in neuronal signaling.
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Affiliation(s)
- Yanshen Zhang
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, MOE Key Laboratory for Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, 230001, Hefei, China
| | - Zhiwen Zhong
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, MOE Key Laboratory for Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, 230001, Hefei, China
| | - Jin Ye
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, MOE Key Laboratory for Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, 230001, Hefei, China.
| | - Chao Wang
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, MOE Key Laboratory for Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, 230001, Hefei, China.
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Zhang H, Lin L, Liu J, Pan L, Lin Z, Zhang M, Zhang J, Cao Y, Zhu J, Zhang R. Phase Separation of MAGI2-Mediated Complex Underlies Formation of Slit Diaphragm Complex in Glomerular Filtration Barrier. J Am Soc Nephrol 2021; 32:1946-1960. [PMID: 34330769 PMCID: PMC8455267 DOI: 10.1681/asn.2020111590] [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: 11/12/2020] [Accepted: 03/22/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Slit diaphragm is a specialized adhesion junction between the opposing podocytes, establishing the final filtration barrier to urinary protein loss. At the cytoplasmic insertion site of each slit diaphragm there is an electron-dense and protein-rich cellular compartment that is essential for slit diaphragm integrity and signal transduction. Mutations in genes that encode components of this membrane-less compartment have been associated with glomerular diseases. However, the molecular mechanism governing formation of compartmentalized slit diaphragm assembly remains elusive. METHODS We systematically investigated the interactions between key components at slit diaphragm, such as MAGI2, Dendrin, and CD2AP, through a combination of biochemical, biophysical, and cell biologic approaches. RESULTS We demonstrated that MAGI2, a unique MAGUK family scaffold protein at slit diaphragm, can autonomously undergo liquid-liquid phase separation. Multivalent interactions among the MAGI2-Dendrin-CD2AP complex drive the formation of the highly dense slit diaphragm condensates at physiologic conditions. The reconstituted slit diaphragm condensates can effectively recruit Nephrin. A nephrotic syndrome-associated mutation of MAGI2 interfered with formation of the slit diaphragm condensates, thus leading to impaired enrichment of Nephrin. CONCLUSIONS Key components at slit diaphragm (e.g., MAGI2 and its complex) can spontaneously undergo phase separation. The reconstituted slit diaphragm condensates can be enriched in adhesion molecules and cytoskeletal adaptor proteins. Therefore, the electron-dense slit diaphragm assembly might form via phase separation of core components of the slit diaphragm in podocytes.
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Affiliation(s)
- Haijiao Zhang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Lin Lin
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Jianping Liu
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Lifeng Pan
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zhijie Lin
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Mingjie Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China,School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Jiong Zhang
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ying Cao
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jinwei Zhu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Rongguang Zhang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
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18
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MAGI1, a Scaffold Protein with Tumor Suppressive and Vascular Functions. Cells 2021; 10:cells10061494. [PMID: 34198584 PMCID: PMC8231924 DOI: 10.3390/cells10061494] [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: 05/07/2021] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
MAGI1 is a cytoplasmic scaffolding protein initially identified as a component of cell-to-cell contacts stabilizing cadherin-mediated cell–cell adhesion in epithelial and endothelial cells. Clinical-pathological and experimental evidence indicates that MAGI1 expression is decreased in some inflammatory diseases, and also in several cancers, including hepatocellular carcinoma, colorectal, cervical, breast, brain, and gastric cancers and appears to act as a tumor suppressor, modulating the activity of oncogenic pathways such as the PI3K/AKT and the Wnt/β-catenin pathways. Genomic mutations and other mechanisms such as mechanical stress or inflammation have been described to regulate MAGI1 expression. Intriguingly, in breast and colorectal cancers, MAGI1 expression is induced by non-steroidal anti-inflammatory drugs (NSAIDs), suggesting a role in mediating the tumor suppressive activity of NSAIDs. More recently, MAGI1 was found to localize at mature focal adhesion and to regulate integrin-mediated adhesion and signaling in endothelial cells. Here, we review MAGI1′s role as scaffolding protein, recent developments in the understanding of MAGI1 function as tumor suppressor gene, its role in endothelial cells and its implication in cancer and vascular biology. We also discuss outstanding questions about its regulation and potential translational implications in oncology.
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19
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Yamada H, Shirata N, Makino S, Miyake T, Trejo JAO, Yamamoto-Nonaka K, Kikyo M, Empitu MA, Kadariswantiningsih IN, Kimura M, Ichimura K, Yokoi H, Mukoyama M, Hotta A, Nishimori K, Yanagita M, Asanuma K. MAGI-2 orchestrates the localization of backbone proteins in the slit diaphragm of podocytes. Kidney Int 2020; 99:382-395. [PMID: 33144214 DOI: 10.1016/j.kint.2020.09.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 08/22/2020] [Accepted: 09/10/2020] [Indexed: 01/19/2023]
Abstract
Podocytes are highly specialized cells within the glomerulus that are essential for ultrafiltration. The slit diaphragm between the foot processes of podocytes functions as a final filtration barrier to prevent serum protein leakage into urine. The slit-diaphragm consists mainly of Nephrin and Neph1, and localization of these backbone proteins is essential to maintaining the integrity of the glomerular filtration barrier. However, the mechanisms that regulate the localization of these backbone proteins have remained elusive. Here, we focused on the role of membrane-associated guanylate kinase inverted 2 (MAGI-2) in order to investigate mechanisms that orchestrate localization of slit-diaphragm backbone proteins. MAGI-2 downregulation coincided with a reduced expression of slit-diaphragm backbone proteins in human kidneys glomerular disease such as focal segmental glomerulosclerosis or IgA nephropathy. Podocyte-specific deficiency of MAGI-2 in mice abrogated localization of Nephrin and Neph1 independently of other scaffold proteins. Although a deficiency of zonula occuldens-1 downregulated the endogenous Neph1 expression, MAGI-2 recovered Neph1 expression at the cellular edge in cultured podocytes. Additionally, overexpression of MAGI-2 preserved Nephrin localization to intercellular junctions. Co-immunoprecipitation and pull-down assays also revealed the importance of the PDZ domains of MAGI-2 for the interaction between MAGI-2 and slit diaphragm backbone proteins in podocytes. Thus, localization and stabilization of Nephrin and Neph1 in intercellular junctions is regulated mainly via the PDZ domains of MAGI-2 together with other slit-diaphragm scaffold proteins. Hence, these findings may elucidate a mechanism by which the backbone proteins are maintained.
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Affiliation(s)
- Hiroyuki Yamada
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan; Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Naritoshi Shirata
- Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharmaceutical Corporation, Saitama, Japan
| | - Shinichi Makino
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan; Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takafumi Miyake
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | | | - Kanae Yamamoto-Nonaka
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Mitsuhiro Kikyo
- Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharmaceutical Corporation, Saitama, Japan
| | - Maulana A Empitu
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | | | - Maiko Kimura
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Koichiro Ichimura
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Hideki Yokoi
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masashi Mukoyama
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan
| | - Akitsu Hotta
- Department of Reprogramming Science, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Katsuhiko Nishimori
- Department of Obesity and Inflammation Research, Fukushima Medical University, Fukushima, Japan
| | - Motoko Yanagita
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Institute for the Advanced Study of Human Biology (ASHBi), Kyoto University, Kyoto, Japan
| | - Katsuhiko Asanuma
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan; Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
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Wilson PC, Love-Gregory L, Corliss M, McNulty S, Heusel JW, Gaut JP. Beyond Panel-Based Testing: Exome Analysis Increases Sensitivity for Diagnosis of Genetic Kidney Disease. KIDNEY360 2020; 1:772-780. [PMID: 35372954 PMCID: PMC8815744 DOI: 10.34067/kid.0001342020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 05/12/2020] [Indexed: 05/16/2023]
Abstract
BACKGROUND Next-generation sequencing (NGS) is a useful tool for evaluating patients with suspected genetic kidney disease. Clinical practice relies on the use of targeted gene panels that are ordered based on patient presentation. We compare the diagnostic yield of clinical panel-based testing to exome analysis. METHODS In total, 324 consecutive patients underwent physician-ordered, panel-based NGS testing between December 2014 and October 2018. Gene panels were available for four clinical phenotypes, including atypical hemolytic uremic syndrome (n=224), nephrotic syndrome (n=56), cystic kidney disease (n=26), and Alport syndrome (n=13). Variants were analyzed and clinical reports were signed out by a pathologist or clinical geneticist at the time of testing. Subsequently, all patients underwent retrospective exome analysis to detect additional clinically significant variants in kidney disease genes that were not analyzed as part of the initial clinical gene panel. Resulting variants were classified according to the American College of Medical Genetics and Genomics 2015 guidelines. RESULTS In the initial physician-ordered gene panels, we identified clinically significant pathogenic or likely pathogenic variants in 13% of patients (n=42/324). CFHR3-CFHR1 homozygous deletion was detected in an additional 13 patients with aHUS without a pathogenic or likely pathogenic variant. Diagnostic yield of the initial physician-ordered gene panel was 20% and varied between groups. Retrospective exome analysis identified 18 patients with a previously unknown pathogenic or likely pathogenic variant in a kidney disease gene and eight patients with a high-risk APOL1 genotype. Overall, retrospective exome analysis increased the diagnostic yield of panel-based testing from 20% to 30%. CONCLUSIONS These results highlight the importance of a broad and collaborative approach between the clinical laboratory and their physician clients that employs additional analysis when a targeted panel of kidney disease-causing genes does not return a clinically meaningful result.
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Affiliation(s)
- Parker C. Wilson
- Division of Anatomic and Molecular Pathology, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri
| | - Latisha Love-Gregory
- Division of Anatomic and Molecular Pathology, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri
| | - Meagan Corliss
- Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri
| | - Samantha McNulty
- Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri
| | - Jonathan W. Heusel
- Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri
| | - Joseph P. Gaut
- Division of Anatomic and Molecular Pathology, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
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21
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Usui T, Morito N, Shawki HH, Sato Y, Tsukaguchi H, Hamada M, Jeon H, Yadav MK, Kuno A, Tsunakawa Y, Okada R, Ojima T, Kanai M, Asano K, Imamura Y, Koshida R, Yoh K, Usui J, Yokoi H, Kasahara M, Yoshimura A, Muratani M, Kudo T, Oishi H, Yamagata K, Takahashi S. Transcription factor MafB in podocytes protects against the development of focal segmental glomerulosclerosis. Kidney Int 2020; 98:391-403. [DOI: 10.1016/j.kint.2020.02.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/21/2020] [Accepted: 02/28/2020] [Indexed: 12/31/2022]
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22
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Mason AE, Sen ES, Bierzynska A, Colby E, Afzal M, Dorval G, Koziell AB, Williams M, Boyer O, Welsh GI, Saleem MA. Response to First Course of Intensified Immunosuppression in Genetically Stratified Steroid Resistant Nephrotic Syndrome. Clin J Am Soc Nephrol 2020; 15:983-994. [PMID: 32317330 PMCID: PMC7341765 DOI: 10.2215/cjn.13371019] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/18/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND OBJECTIVES Intensified immunosuppression in steroid-resistant nephrotic syndrome is broadly applied, with disparate outcomes. This review of patients from the United Kingdom National Study of Nephrotic Syndrome cohort aimed to improve disease stratification by determining, in comprehensively genetically screened patients with steroid-resistant nephrotic syndrome, if there is an association between response to initial intensified immunosuppression and disease progression and/or post-transplant recurrence. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Pediatric patients with steroid-resistant nephrotic syndrome were recruited via the UK National Registry of Rare Kidney Diseases. All patients were whole-genome sequenced, whole-exome sequenced, or steroid-resistant nephrotic syndrome gene-panel sequenced. Complete response or partial response within 6 months of starting intensified immunosuppression was ascertained using laboratory data. Response to intensified immunosuppression and outcomes were analyzed according to genetic testing results, pattern of steroid resistance, and first biopsy findings. RESULTS Of 271 patients, 178 (92 males, median onset age 4.7 years) received intensified immunosuppression with response available. A total of 4% of patients with monogenic disease showed complete response, compared with 25% of genetic-testing-negative patients (P=0.02). None of the former recurred post-transplantation. In genetic-testing-negative patients, 97% with complete response to first intensified immunosuppression did not progress, whereas 44% of nonresponders developed kidney failure with 73% recurrence post-transplant. Secondary steroid resistance had a higher complete response rate than primary/presumed resistance (43% versus 23%; P=0.001). The highest complete response rate in secondary steroid resistance was to rituximab (64%). Biopsy results showed no correlation with intensified immunosuppression response or outcome. CONCLUSIONS Patients with monogenic steroid-resistant nephrotic syndrome had a poor therapeutic response and no post-transplant recurrence. In genetic-testing-negative patients, there was an association between response to first intensified immunosuppression and long-term outcome. Patients with complete response rarely progressed to kidney failure, whereas nonresponders had poor kidney survival and a high post-transplant recurrence rate. Patients with secondary steroid resistance were more likely to respond, particularly to rituximab.
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Affiliation(s)
- Anna E. Mason
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Ethan S. Sen
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Agnieszka Bierzynska
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Elizabeth Colby
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Maryam Afzal
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Guillaume Dorval
- Department of Pediatric Nephrology, Reference Center for Hereditary Kidney Diseases, Necker Hospital, Assistance Publique—Hôpitaux de Paris, Paris, France
| | - Ania B. Koziell
- Division of Transplantation Immunology and Mucosal Biology, Department of Experimental Immunobiology, Faculty of Life Sciences and Medicine, King’s College London, London, United Kingdom
| | - Maggie Williams
- Bristol Genetics Laboratory, Pathology Sciences, Southmead Hospital, Bristol, United Kingdom
| | - Olivia Boyer
- Department of Pediatric Nephrology, Reference Center for Hereditary Kidney Diseases, Necker Hospital, Assistance Publique—Hôpitaux de Paris, Paris, France
| | - Gavin I. Welsh
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Moin A. Saleem
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - on behalf of the UK RaDaR/NephroS Study
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
- Department of Pediatric Nephrology, Reference Center for Hereditary Kidney Diseases, Necker Hospital, Assistance Publique—Hôpitaux de Paris, Paris, France
- Division of Transplantation Immunology and Mucosal Biology, Department of Experimental Immunobiology, Faculty of Life Sciences and Medicine, King’s College London, London, United Kingdom
- Bristol Genetics Laboratory, Pathology Sciences, Southmead Hospital, Bristol, United Kingdom
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23
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Li AS, Ingham JF, Lennon R. Genetic Disorders of the Glomerular Filtration Barrier. Clin J Am Soc Nephrol 2020; 15:1818-1828. [PMID: 32205319 PMCID: PMC7769017 DOI: 10.2215/cjn.11440919] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The glomerular filtration barrier is a highly specialized capillary wall comprising fenestrated endothelial cells, podocytes, and an intervening basement membrane. In glomerular disease, this barrier loses functional integrity, allowing the passage of macromolecules and cells, and there are associated changes in both cell morphology and the extracellular matrix. Over the past 3 decades, there has been a transformation in our understanding about glomerular disease, fueled by genetic discovery, and this is leading to exciting advances in our knowledge about glomerular biology and pathophysiology. In current clinical practice, a genetic diagnosis already has important implications for management, ranging from estimating the risk of disease recurrence post-transplant to the life-changing advances in the treatment of atypical hemolytic uremic syndrome. Improving our understanding about the mechanistic basis of glomerular disease is required for more effective and personalized therapy options. In this review, we describe genotype and phenotype correlations for genetic disorders of the glomerular filtration barrier, with a particular emphasis on how these gene defects cluster by both their ontology and patterns of glomerular pathology.
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Affiliation(s)
- Anna S Li
- Division of Cell-Matrix Biology and Regenerative Medicine, Wellcome Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom.,Department of Nephrology, Manchester University Hospitals National Health Service Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Jack F Ingham
- Division of Cell-Matrix Biology and Regenerative Medicine, Wellcome Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
| | - Rachel Lennon
- Division of Cell-Matrix Biology and Regenerative Medicine, Wellcome Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom .,Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals National Health Service Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
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24
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Imprinted genes in clinical exome sequencing: Review of 538 cases and exploration of mouse-human conservation in the identification of novel human disease loci. Eur J Med Genet 2020; 63:103903. [PMID: 32169557 DOI: 10.1016/j.ejmg.2020.103903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 01/20/2020] [Accepted: 03/09/2020] [Indexed: 01/01/2023]
Abstract
Human imprinting disorders cause a range of dysmorphic and neurocognitive phenotypes, and they may elude traditional molecular diagnosis such exome sequencing. The discovery of novel disorders related to imprinted genes has lagged behind traditional Mendelian disorders because current diagnostic technology, especially unbiased testing, has limited utility in their discovery. To identify novel imprinting disorders, we reviewed data for every human gene hypothesized to be imprinted, identified each mouse ortholog, determined its imprinting status in the mouse, and analyzed its function in humans and mice. We identified 17 human genes that are imprinted in both humans and mice, and have functional data in mice or humans to suggest that dysregulated expression would lead to an abnormal phenotype in humans. These 17 genes, along with known imprinted genes, were preferentially flagged 538 clinical exome sequencing tests. The identified genes were: DIRAS3 [1p31.3], TP73 [1p36.32], SLC22A3 [6q25.3], GRB10 [7p12.1], DDC [7p12.2], MAGI2 [7q21.11], PEG10 [7q21.3], PPP1R9A [7q21.3], CALCR [7q21.3], DLGAP2 [8p23.3], GLIS3 [9p24.2], INPP5F [10q26.11], ANO1 [11q13.3], SLC38A4 [12q13.11], GATM [15q21.1], PEG3 [19q13.43], and NLRP2 [19q13.42]. In the 538 clinical cases, eight cases (1.7%) reported variants in a causative known imprinted gene. There were 367/758 variants (48.4%) in imprinted genes that were not known to cause disease, but none of those variants met the criteria for clinical reporting. Imprinted disorders play a significant role in human disease, and additional human imprinted disorders remain to be discovered. Therefore, evolutionary conservation is a potential tool to identify novel genes involved in human imprinting disorders and to identify them in clinical testing.
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25
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Zhang Y, Chen Y, Hu T. PANDA: Prioritization of autism-genes using network-based deep-learning approach. Genet Epidemiol 2020; 44:382-394. [PMID: 32039500 DOI: 10.1002/gepi.22282] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/31/2019] [Accepted: 01/27/2020] [Indexed: 11/06/2022]
Abstract
Understanding the genetic background of complex diseases and disorders plays an essential role in the promising precision medicine. The evaluation of candidate genes, however, requires time-consuming and expensive experiments given a large number of possibilities. Thus, computational methods have seen increasing applications in predicting gene-disease associations. We proposed a bioinformatics framework, Prioritization of Autism-genes using Network-based Deep-learning Approach (PANDA). Our approach aims to identify autism-genes across the human genome based on patterns of gene-gene interactions and topological similarity of genes in the interaction network. PANDA trains a graph deep learning classifier using the input of the human molecular interaction network and predicts and ranks the probability of autism association of every node (gene) in the network. PANDA was able to achieve a high classification accuracy of 89%, outperforming three other commonly used machine learning algorithms. Moreover, the gene prioritization ranking list produced by PANDA was evaluated and validated using an independent large-scale exome-sequencing study. The top 10% of PANDA-ranked genes were found significantly enriched for autism association.
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Affiliation(s)
- Yu Zhang
- Department of Computer Science, Memorial University, St. John's, Newfoundland and Labrador, Canada
| | - Yuanzhu Chen
- Department of Computer Science, Memorial University, St. John's, Newfoundland and Labrador, Canada
| | - Ting Hu
- Department of Computer Science, Memorial University, St. John's, Newfoundland and Labrador, Canada.,School of Computing, Queen's University, Kingston, Ontario, Canada
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26
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Genetic studies of focal segmental glomerulosclerosis: a waste of scientific time? Pediatr Nephrol 2020; 35:9-16. [PMID: 30591974 PMCID: PMC6901409 DOI: 10.1007/s00467-018-4161-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 12/21/2022]
Abstract
Many genetic causes of focal segmental glomerulosclerosis (FSGS) have been described. A paradox is that the science in the molecular biology, which generally appears of high quality, is not mirrored by a similarly critical analysis of the renal pathology. FSGS has been applied to such a wide range of conditions that it can reasonably be said to have no useful meaning. Attempts to refine the term have been largely ignored. Study of 252 papers on genetic causes of FSGS found various clinical features. Many papers took the reported diagnosis without question. Few papers reported a pathological review, almost half reported FSGS and up to six other conditions caused by any particular gene, some reported FSGS with recognisable glomerular disorders, over 80% did not apply the Columbia classification, and in nearly all with photomicrographs, the images were not useful for refinement of FSGS. Some workers commented on a lack of genotype-phenotype correlation. One reason is a disregard of the principle that scientific investigation requires an unambiguous definition of the condition studied, to allow others to replicate or refute the findings. Genetic studies of FSGS should use a similarly rigorous approach to renal pathology to that used in molecular biology.
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27
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Kamei K, Ishikura K, Sako M, Ito S, Nozu K, Iijima K. Rituximab therapy for refractory steroid-resistant nephrotic syndrome in children. Pediatr Nephrol 2020; 35:17-24. [PMID: 30564879 DOI: 10.1007/s00467-018-4166-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 12/24/2022]
Abstract
Patients with steroid-resistant nephrotic syndrome (SRNS) who develop resistance to immunosuppressive agents, defined as refractory SRNS, have poor renal outcomes. Although the chimeric anti-CD20 monoclonal antibody rituximab has shown efficacy for frequently relapsing nephrotic syndrome and steroid-dependent nephrotic syndrome, its efficacy for refractory SRNS remains uncertain due to limited data. According to previous case reports, 50.4% of patients with refractory SRNS showed clinical improvements after rituximab treatment. Remission rates in patients with initial steroid resistance and late steroid resistance were 43.9 and 57.7%, respectively, and 41.5 and 63.6% in patients with focal segmental glomerulosclerosis and minor glomerular abnormalities, respectively. However, various factors (race, disease severity, number of rituximab doses, concomitant treatments, and observation period) differed among these observational studies and their consensus may also have been affected by potential publication bias. Rituximab monotherapy may have some degree of efficacy and lead to satisfactory outcomes in a subset of patients with refractory SRNS. However, administration of concomitant treatments during rituximab-mediated B cell depletion, such as methylprednisolone pulse therapy, daily oral prednisolone therapy, and immunosuppressive agents, may lead to better outcomes in these patients. Large-scale, multi-center prospective studies are needed to evaluate the efficacy and safety of such regimens.
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Affiliation(s)
- Koichi Kamei
- Division of Nephrology and Rheumatology, National Center for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo, 157-8535, Japan
| | - Kenji Ishikura
- Division of Nephrology and Rheumatology, National Center for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo, 157-8535, Japan
| | - Mayumi Sako
- Division for Clinical Trials, Department of Clinical Research, Center for Clinical Research and Development, National Center for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo, 157-8535, Japan
| | - Shuichi Ito
- Department of Pediatrics, Graduate School of Medicine, Yokohama City University, 3-9, Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
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28
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Rinschen MM, Gödel M, Grahammer F, Zschiedrich S, Helmstädter M, Kretz O, Zarei M, Braun DA, Dittrich S, Pahmeyer C, Schroder P, Teetzen C, Gee H, Daouk G, Pohl M, Kuhn E, Schermer B, Küttner V, Boerries M, Busch H, Schiffer M, Bergmann C, Krüger M, Hildebrandt F, Dengjel J, Benzing T, Huber TB. A Multi-layered Quantitative In Vivo Expression Atlas of the Podocyte Unravels Kidney Disease Candidate Genes. Cell Rep 2019; 23:2495-2508. [PMID: 29791858 PMCID: PMC5986710 DOI: 10.1016/j.celrep.2018.04.059] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 02/07/2018] [Accepted: 04/15/2018] [Indexed: 12/31/2022] Open
Abstract
Damage to and loss of glomerular podocytes has been identified as the culprit lesion in progressive kidney diseases. Here, we combine mass spectrometry-based proteomics with mRNA sequencing, bioinformatics, and hypothesis-driven studies to provide a comprehensive and quantitative map of mammalian podocytes that identifies unanticipated signaling pathways. Comparison of the in vivo datasets with proteomics data from podocyte cell cultures showed a limited value of available cell culture models. Moreover, in vivo stable isotope labeling by amino acids uncovered surprisingly rapid synthesis of mitochondrial proteins under steady-state conditions that was perturbed under autophagy-deficient, disease-susceptible conditions. Integration of acquired omics dimensions suggested FARP1 as a candidate essential for podocyte function, which could be substantiated by genetic analysis in humans and knockdown experiments in zebrafish. This work exemplifies how the integration of multi-omics datasets can identify a framework of cell-type-specific features relevant for organ health and disease. Deep proteome and transcriptome analyses of native podocytes unravel druggable targets Static and dynamic proteomics uncover features of podocyte identity and proteostasis Candidate genes for nephrotic syndrome were predicted based on multi-omic integration FARP1 is a previously unreported candidate gene for human proteinuric kidney disease
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Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, 50931 Cologne, Germany.
| | - Markus Gödel
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Florian Grahammer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Stefan Zschiedrich
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Oliver Kretz
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Mostafa Zarei
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79104 Freiburg, Germany; Center for Systems Biology (ZBSA), Albert Ludwigs University, 79104 Freiburg, Germany
| | - Daniela A Braun
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Sebastian Dittrich
- Department II of Internal Medicine, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Caroline Pahmeyer
- Department II of Internal Medicine, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Patricia Schroder
- Department of Medicine/Nephrology, Hannover Medical School, 30625 Hannover, Germany; Mount Desert Island Biological Laboratory, Salisbury Cove, ME 04609, USA
| | - Carolin Teetzen
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - HeonYung Gee
- Mount Desert Island Biological Laboratory, Salisbury Cove, ME 04609, USA; Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Ghaleb Daouk
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Martin Pohl
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center and Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Elisa Kuhn
- Center for Human Genetics, Bioscientia, 55218 Ingelheim, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, 50931 Cologne, Germany
| | - Victoria Küttner
- Department for Neuroanatomy, University of Freiburg, 79104 Freiburg, Germany; Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79104 Freiburg, Germany; Department of Dermatology, Medical Center - University of Freiburg, 79106 Freiburg, Germany
| | - Melanie Boerries
- Systems Biology of the Cellular Microenvironment Group, Institute of Molecular Medicine and Cell Research, Albert Ludwigs University Freiburg, 79106 Freiburg, Germany; German Cancer Consortium (DKTK), 79106 Freiburg, Germany; German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Hauke Busch
- Systems Biology of the Cellular Microenvironment Group, Institute of Molecular Medicine and Cell Research, Albert Ludwigs University Freiburg, 79106 Freiburg, Germany; Lübeck Institute for Experimental Dermatology (LIED), University of Lübeck, 23562 Lübeck, Germany
| | - Mario Schiffer
- Department of Medicine/Nephrology, Hannover Medical School, 30625 Hannover, Germany; Mount Desert Island Biological Laboratory, Salisbury Cove, ME 04609, USA
| | - Carsten Bergmann
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany; Center for Human Genetics, Bioscientia, 55218 Ingelheim, Germany
| | - Marcus Krüger
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Friedhelm Hildebrandt
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Joern Dengjel
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79104 Freiburg, Germany; Center for Systems Biology (ZBSA), Albert Ludwigs University, 79104 Freiburg, Germany; Department of Dermatology, Medical Center - University of Freiburg, 79106 Freiburg, Germany; Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland; BIOSS Centre for Biological Signaling Studies, Albert Ludwigs University Freiburg, 79104 Freiburg, Germany
| | - Thomas Benzing
- Department II of Internal Medicine, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, 50931 Cologne, Germany.
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany; Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79104 Freiburg, Germany; Center for Systems Biology (ZBSA), Albert Ludwigs University, 79104 Freiburg, Germany; BIOSS Centre for Biological Signaling Studies, Albert Ludwigs University Freiburg, 79104 Freiburg, Germany.
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29
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Kampf LL, Schneider R, Gerstner L, Thünauer R, Chen M, Helmstädter M, Amar A, Onuchic-Whitford AC, Loza Munarriz R, Berdeli A, Müller D, Schrezenmeier E, Budde K, Mane S, Laricchia KM, Rehm HL, MacArthur DG, Lifton RP, Walz G, Römer W, Bergmann C, Hildebrandt F, Hermle T. TBC1D8B Mutations Implicate RAB11-Dependent Vesicular Trafficking in the Pathogenesis of Nephrotic Syndrome. J Am Soc Nephrol 2019; 30:2338-2353. [PMID: 31732614 DOI: 10.1681/asn.2019040414] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 08/07/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Mutations in about 50 genes have been identified as monogenic causes of nephrotic syndrome, a frequent cause of CKD. These genes delineated the pathogenetic pathways and rendered significant insight into podocyte biology. METHODS We used whole-exome sequencing to identify novel monogenic causes of steroid-resistant nephrotic syndrome (SRNS). We analyzed the functional significance of an SRNS-associated gene in vitro and in podocyte-like Drosophila nephrocytes. RESULTS We identified hemizygous missense mutations in the gene TBC1D8B in five families with nephrotic syndrome. Coimmunoprecipitation assays indicated interactions between TBC1D8B and active forms of RAB11. Silencing TBC1D8B in HEK293T cells increased basal autophagy and exocytosis, two cellular functions that are independently regulated by RAB11. This suggests that TBC1D8B plays a regulatory role by inhibiting endogenous RAB11. Coimmunoprecipitation assays showed TBC1D8B also interacts with the slit diaphragm protein nephrin, and colocalizes with it in immortalized cell lines. Overexpressed murine Tbc1d8b with patient-derived mutations had lower affinity for endogenous RAB11 and nephrin compared with wild-type Tbc1d8b protein. Knockdown of Tbc1d8b in Drosophila impaired function of the podocyte-like nephrocytes, and caused mistrafficking of Sns, the Drosophila ortholog of nephrin. Expression of Rab11 RNAi in nephrocytes entailed defective delivery of slit diaphragm protein to the membrane, whereas RAB11 overexpression revealed a partial phenotypic overlap to Tbc1d8b loss of function. CONCLUSIONS Novel mutations in TBC1D8B are monogenic causes of SRNS. This gene inhibits RAB11. Our findings suggest that RAB11-dependent vesicular nephrin trafficking plays a role in the pathogenesis of nephrotic syndrome.
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Affiliation(s)
- Lina L Kampf
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Ronen Schneider
- Division of Nephrology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Lea Gerstner
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Roland Thünauer
- Signalling Research Centres BIOSS and CIBSS and Faculty of Biology, University of Freiburg, Freiburg, Germany.,Advanced Light and Fluorescence Microscopy Facility, Centre for Structural Systems Biology (CSSB) and University of Hamburg, Hamburg, Germany
| | - Mengmeng Chen
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Martin Helmstädter
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Ali Amar
- Division of Nephrology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ana C Onuchic-Whitford
- Division of Nephrology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Renal Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Afig Berdeli
- Department of Pediatrics, Molecular Medicine Laboratory, Ege University, Izmir, Turkey
| | - Dominik Müller
- Department of Pediatric Nephrology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Eva Schrezenmeier
- Department of Nephrology and Medical Intensive Care, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Klemens Budde
- Department of Nephrology and Medical Intensive Care, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Shrikant Mane
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Kristen M Laricchia
- Broad Center for Mendelian Genomics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge
| | - Heidi L Rehm
- Broad Center for Mendelian Genomics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge
| | - Daniel G MacArthur
- Broad Center for Mendelian Genomics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge
| | - Richard P Lifton
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut.,Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, New York
| | - Gerd Walz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Winfried Römer
- Signalling Research Centres BIOSS and CIBSS and Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Carsten Bergmann
- Center for Human Genetics, Mainz, Germany.,Center for Human Genetics, Bioscientia, Ingelheim, Germany; and.,Department of Medicine, University Hospital Freiburg, Freiburg, Germany
| | - Friedhelm Hildebrandt
- Division of Nephrology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts;
| | - Tobias Hermle
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany;
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30
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Meyer-Schwesinger C. An unexpected role of steroid on podocytes: from zebrafish to human nephrotic syndrome? Kidney Int 2019; 95:1015-1017. [PMID: 31010473 DOI: 10.1016/j.kint.2019.01.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 01/19/2019] [Accepted: 01/23/2019] [Indexed: 10/27/2022]
Abstract
In this issue of Kidney International, Jobst-Schwan et al. developed a zebrafish model of MAGI2-deficiency, which recapitulates findings of human nephrotic syndrome due to MAGI2 mutations. The authors use this model system to screen for drugs that might target and alleviate MAGI2-associated nephrotic syndrome pathways. The scientific context of this publication and the significance of its key findings are discussed in this commentary.
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Affiliation(s)
- Catherine Meyer-Schwesinger
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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31
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Molecular stratification of idiopathic nephrotic syndrome. Nat Rev Nephrol 2019; 15:750-765. [DOI: 10.1038/s41581-019-0217-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2019] [Indexed: 01/03/2023]
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32
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Guaragna MS, de Brito Lutaif ACG, de Souza ML, Maciel-Guerra AT, Belangero VMS, Guerra-Júnior G, de Mello MP. Promises and pitfalls of whole-exome sequencing exemplified by a nephrotic syndrome family. Mol Genet Genomics 2019; 295:135-142. [PMID: 31520189 DOI: 10.1007/s00438-019-01609-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/05/2019] [Indexed: 01/12/2023]
Abstract
High-throughput techniques such as whole-exome sequencing (WES) show promise for the identification of candidate genes that underlie Mendelian diseases such as nephrotic syndrome (NS). These techniques have enabled the identification of a proportion of the approximately 54 genes associated with NS. However, the main pitfall of using WES in clinical and research practice is the identification of multiple variants, which hampers interpretation during downstream analysis. One useful strategy is to evaluate the co-inheritance of rare variants in affected family members. Here, we performed WES of a patient with steroid-resistant NS (SRNS) and intermittent microhematuria. Currently, 15 years after kidney transplantation, this patient presents normal kidney function. The patient was found to be homozygous for a rare MYO1E stop-gain variant, and was heterozygous for rare variants in NS-associated genes, COL4A4, KANK1, LAMB2, ANLN, E2F3, and APOL1. We evaluated the presence or absence of these variants in both parents and 11 siblings, three of whom exhibited a milder phenotype of the kidney disease. Analysis of variant segregation in the family, indicated the MYO1E stop-gain variant as the putative causal variant underlying the kidney disease in the patient and two of her affected sisters. Two secondary variants in COL4A4-identified in some other affected family members-require further functional studies to determine whether they play a role in the development of microhematuria in affected family members. Our data illustrate the difficulties in distinguishing the causal pathogenic variants from incidental findings after WES-based variant analysis, especially in heterogenous genetic conditions, such as NS.
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Affiliation(s)
- Mara Sanches Guaragna
- Laboratory of Human Molecular Genetics, Center for Molecular Biology and Genetic Engineering (CBMEG), State University of Campinas, UNICAMP, Caixa Postal 6010, 13083-875, Campinas, SP, Brazil.
| | - Anna Cristina Gervásio de Brito Lutaif
- Integrated Center of Pediatric Nephrology (CIN), Department of Pediatrics, School of Medical Sciences (FCM), State University of Campinas, UNICAMP, Campinas, Brazil
| | - Marcela Lopes de Souza
- Laboratory of Human Molecular Genetics, Center for Molecular Biology and Genetic Engineering (CBMEG), State University of Campinas, UNICAMP, Caixa Postal 6010, 13083-875, Campinas, SP, Brazil
| | | | - Vera Maria Santoro Belangero
- Integrated Center of Pediatric Nephrology (CIN), Department of Pediatrics, School of Medical Sciences (FCM), State University of Campinas, UNICAMP, Campinas, Brazil.,Department of Pediatrics, School of Medical Sciences (FCM), UNICAMP, Campinas, SP, Brazil
| | - Gil Guerra-Júnior
- Department of Pediatrics, School of Medical Sciences (FCM), UNICAMP, Campinas, SP, Brazil.,Growth and Development Laboratory, Center for Investigation in Pediatrics (CIPED), School of Medical Sciences (FCM), UNICAMP, Campinas, SP, Brazil
| | - Maricilda Palandi de Mello
- Laboratory of Human Molecular Genetics, Center for Molecular Biology and Genetic Engineering (CBMEG), State University of Campinas, UNICAMP, Caixa Postal 6010, 13083-875, Campinas, SP, Brazil
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33
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Zhu B, Cao A, Li J, Young J, Wong J, Ashraf S, Bierzynska A, Menon MC, Hou S, Sawyers C, Campbell KN, Saleem MA, He JC, Hildebrandt F, D'Agati VD, Peng W, Kaufman L. Disruption of MAGI2-RapGEF2-Rap1 signaling contributes to podocyte dysfunction in congenital nephrotic syndrome caused by mutations in MAGI2. Kidney Int 2019; 96:642-655. [PMID: 31171376 PMCID: PMC7259463 DOI: 10.1016/j.kint.2019.03.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 03/03/2019] [Accepted: 03/14/2019] [Indexed: 11/21/2022]
Abstract
The essential role of membrane associated guanylate kinase 2 (MAGI2) in podocytes is indicated by the phenotypes of severe glomerulosclerosis of both MAGI2 knockout mice and in patients with congenital nephrotic syndrome (CNS) caused by mutations in MAGI2. Here, we show that MAGI2 forms a complex with the Rap1 guanine nucleotide exchange factor, RapGEF2, and that this complex is lost when expressing MAGI2 CNS variants. Co-expression of RapGEF2 with wild-type MAGI2, but not MAGI2 CNS variants, enhanced activation of the small GTPase Rap1, a central signaling node in podocytes. In mice, podocyte-specific RapGEF2 deletion resulted in spontaneous glomerulosclerosis, with qualitative glomerular features comparable to MAGI2 knockout mice. Knockdown of RapGEF2 or MAGI2 in human podocytes caused similar reductions in levels of Rap1 activation and Rap1-mediated downstream signaling. Furthermore, human podocytes expressing MAGI2 CNS variants show severe abnormalities of cellular morphology and dramatic loss of actin cytoskeletal organization, features completely rescued by pharmacological activation of Rap1 via a non-MAGI2 dependent upstream pathway. Finally, immunostaining of kidney sections from patients with congenital nephrotic syndrome and MAGI2 mutations showed reduced podocyte Rap1-mediated signaling. Thus, MAGI2-RapGEF2-Rap1 signaling is essential for normal podocyte function. Hence, disruption of this pathway is an important cause of the renal phenotype induced by MAGI2 CNS mutations.
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Affiliation(s)
- Bingbing Zhu
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA; Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Aili Cao
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA; Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jianhua Li
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - James Young
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Jenny Wong
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Shazia Ashraf
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Agnieszka Bierzynska
- University of Bristol, Children's Renal Unit and Bristol Renal, Bristol, United Kingdom
| | - Madhav C Menon
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Steven Hou
- National Cancer Institute, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Charles Sawyers
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Kirk N Campbell
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Moin A Saleem
- University of Bristol, Children's Renal Unit and Bristol Renal, Bristol, United Kingdom
| | - John C He
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Friedhelm Hildebrandt
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Vivette D D'Agati
- Renal Pathology Laboratory, Columbia University Medical Center, New York, New York, USA
| | - Wen Peng
- Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Lewis Kaufman
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
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34
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Ding WY, Beresford MW, Saleem MA, Ramanan AV. Big data and stratified medicine: what does it mean for children? Arch Dis Child 2019; 104:389-394. [PMID: 30266876 DOI: 10.1136/archdischild-2018-315125] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 08/28/2018] [Accepted: 08/29/2018] [Indexed: 01/15/2023]
Abstract
Stratified medicine in paediatrics is increasingly becoming a reality, as our understanding of disease pathogenesis improves and novel treatment targets emerge. We have already seen some success in paediatrics in targeted therapies such as cystic fibrosis for specific cystic fibrosis transmembrane conductance regulator variants. With the increased speed and decreased cost of processing and analysing data from rare disease registries, we are increasingly able to use a systems biology approach (including '-omics') to screen across populations for molecules and genes of interest. Improving our understanding of the molecular mechanisms underlying disease, and how to classify patients according to these will lead the way for targeted therapies for individual patients. This review article will summarise how 'big data' and the 'omics' are being used and developed, and taking examples from paediatric renal medicine and rheumatology, demonstrate progress being made towards stratified medicine for children.
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Affiliation(s)
- Wen Y Ding
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Michael W Beresford
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK.,Department of Paediatric Rheumatology, Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - Moin A Saleem
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.,Department of Paediatric Rheumatology, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.,Department of Paediatric Nephrology, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - Athimalaipet V Ramanan
- Department of Paediatric Rheumatology, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.,Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
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35
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Jobst-Schwan T, Hoogstraten CA, Kolvenbach CM, Schmidt JM, Kolb A, Eddy K, Schneider R, Ashraf S, Widmeier E, Majmundar AJ, Hildebrandt F. Corticosteroid treatment exacerbates nephrotic syndrome in a zebrafish model of magi2a knockout. Kidney Int 2019; 95:1079-1090. [PMID: 31010479 DOI: 10.1016/j.kint.2018.12.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/21/2018] [Accepted: 12/13/2018] [Indexed: 01/31/2023]
Abstract
Recently, recessive mutations of MAGI2 were identified as a cause of steroid-resistant nephrotic syndrome (SRNS) in humans and mice. To further delineate the pathogenesis of MAGI2 loss of function, we generated stable knockout lines for the two zebrafish orthologues magi2a and magi2b by CRISPR/Cas9. We also developed a novel assay for the direct detection of proteinuria in zebrafish independent of transgenic background. Whereas knockout of magi2b did not yield a nephrotic syndrome phenotype, magi2a-/- larvae developed ascites, periorbital edema, and proteinuria, as indicated by increased excretion of low molecular weight protein. Electron microscopy demonstrated extensive podocyte foot process effacement. As in human SRNS, we observed genotype/phenotype correlation, with edema onset occurring earlier in zebrafish with truncating alleles (5-6 days post fertilization) versus hypomorphic alleles (19-20 days post fertilization). Paradoxically, corticosteroid treatment exacerbated the phenotype, with earlier onset of edema. In contrast, treatment with cyclosporine A or tacrolimus had no significant effect. Although RhoA signaling has been implicated as a downstream mediator of MAGI2 activity, targeting of the RhoA pathway did not modify the nephrotic syndrome phenotype. In the first CRISPR/Cas9 zebrafish knockout model of SRNS, we found that corticosteroids may have a paradoxical effect in the setting of specific genetic mutations.
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Affiliation(s)
- Tilman Jobst-Schwan
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Charlotte A Hoogstraten
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Caroline M Kolvenbach
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Johanna Magdalena Schmidt
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Amy Kolb
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Kaitlyn Eddy
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ronen Schneider
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Shazia Ashraf
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Eugen Widmeier
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Amar J Majmundar
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Friedhelm Hildebrandt
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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36
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Advances in molecular diagnosis and therapeutics in nephrotic syndrome and focal and segmental glomerulosclerosis. Curr Opin Nephrol Hypertens 2019; 27:194-200. [PMID: 29465426 DOI: 10.1097/mnh.0000000000000408] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE OF REVIEW The widespread adoption of next-generation sequencing by research and clinical laboratories has begun to uncover the previously unknown genetic basis of many diseases. In nephrology, one of the best examples of this is seen in focal and segmental glomerulosclerosis (FSGS) and nephrotic syndrome. We review advances made in 2017 as a result of human and molecular genetic studies as it relates to FSGS and nephrotic syndrome. RECENT FINDINGS There are more than 50 monogenic genes described in steroid-resistant nephrotic syndrome and FSGS, with seven reported in 2017. In individuals presenting with FSGS or nephrotic syndrome before or at the age of 18 years, the commonest genes in which a mutation is found continues to be limited to only a few including NPHS1 and NPHS2 based on multiple studies. For FSGS or nephrotic syndrome that presents after 18 years, mutations in COl4A3/4/5, traditionally associated with Alport syndrome, are increasingly being reported. Despite the extensive genetic heterogeneity in FSGS, there is evidence that some of these genes converge onto common pathways. There are also reports of in-vivo models exploring apolipoprotein 1 biology, variants in which account for part of the increased risk of nondiabetic kidney disease in African-Americans. Finally, genetic testing has several clinical uses including clarification of diagnosis and treatment; identification of suitable young biologic relatives for kidney donation; and preimplantation genetic diagnosis. CRISPR gene editing is currently an experimental tool only, but the recent reports of excising mutations in embryos could be a therapeutic option for individuals with any monogenic disorder in the future. SUMMARY Sequencing efforts are bringing novel variants into investigation and directing the efforts to understand how these lead to disease phenotypes. Expanding our understanding of the genetic basis of health and disease processes is the necessary first step to elaborate the repertoire of therapeutic agents available for patients with FSGS and nephrotic syndrome.
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37
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Stone H, Magella B, Bennett MR. The Search for Biomarkers to Aid in Diagnosis, Differentiation, and Prognosis of Childhood Idiopathic Nephrotic Syndrome. Front Pediatr 2019; 7:404. [PMID: 31681707 PMCID: PMC6805718 DOI: 10.3389/fped.2019.00404] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 09/18/2019] [Indexed: 12/13/2022] Open
Abstract
Identification of genes associated with childhood-onset nephrotic syndrome has significantly advanced our understanding of the pathogenesis of this complex disease over the past two decades, however the precise etiology in many cases remains unclear. At this time, we still rely on invasive kidney biopsy to determine the underlying cause of nephrotic syndrome in adults. In children, response to steroid therapy has been shown to be the best indicator of prognosis, and therefore all children are treated initially with corticosteroids. Because this strategy exposes a large number of children to the toxicities of steroids without providing any benefit, many researchers have sought to find a marker that could predict a patient's response to steroids at the time of diagnosis. Additionally, the identification of such a marker could provide prognostic information about a patient's response to medications, progression to end stage renal disease, and risk of disease recurrence following transplantation. Major advances have been made in understanding how genetic biomarkers can be used to predict a patient's response to therapies and disease course, especially after transplantation. Research attempting to identify urine- and serum-based biomarkers which could be used for the diagnosis, differentiation, and prognosis of nephrotic syndrome has become an area of emphasis. In this review, we explore the most exciting biomarkers and their potential clinical applications.
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Affiliation(s)
- Hillarey Stone
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Bliss Magella
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Michael R Bennett
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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38
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Lane BM, Cason R, Esezobor CI, Gbadegesin RA. Genetics of Childhood Steroid Sensitive Nephrotic Syndrome: An Update. Front Pediatr 2019; 7:8. [PMID: 30761277 PMCID: PMC6361778 DOI: 10.3389/fped.2019.00008] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/11/2019] [Indexed: 12/12/2022] Open
Abstract
Advances in genome science in the last 20 years have led to the discovery of over 50 single gene causes and genetic risk loci for steroid resistant nephrotic syndrome (SRNS). Despite these advances, the genetic architecture of childhood steroid sensitive nephrotic syndrome (SSNS) remains poorly understood due in large part to the varying clinical course of SSNS over time. Recent exome and genome wide association studies from well-defined cohorts of children with SSNS identified variants in multiple MHC class II molecules such as HLA-DQA1 and HLA-DQB1 as risk factors for SSNS, thus stressing the central role of adaptive immunity in the pathogenesis of SSNS. However, evidence suggests that unknown second hit risk loci outside of the MHC locus and environmental factors also make significant contributions to disease. In this review, we examine what is currently known about the genetics of SSNS, the implications of recent findings on our understanding of pathogenesis of SSNS, and how we can utilize these results and findings from future studies to improve the management of children with nephrotic syndrome.
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Affiliation(s)
- Brandon M Lane
- Division of Nephrology, Departments of Pediatrics, Duke University Medical Center, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | - Rachel Cason
- Division of Nephrology, Departments of Pediatrics, Duke University Medical Center, Durham, NC, United States
| | | | - Rasheed A Gbadegesin
- Division of Nephrology, Departments of Pediatrics, Duke University Medical Center, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
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39
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Genetic testing in steroid-resistant nephrotic syndrome: why, who, when and how? Pediatr Nephrol 2019; 34:195-210. [PMID: 29181713 PMCID: PMC6311200 DOI: 10.1007/s00467-017-3838-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 10/24/2017] [Accepted: 10/25/2017] [Indexed: 12/23/2022]
Abstract
Steroid-resistant nephrotic syndrome (SRNS) is a common cause of chronic kidney disease in childhood and has a significant risk of rapid progression to end-stage renal disease. The identification of over 50 monogenic causes of SRNS has revealed dysfunction in podocyte-associated proteins in the pathogenesis of proteinuria, highlighting their essential role in glomerular function. Recent technological advances in high-throughput sequencing have enabled indication-driven genetic panel testing for patients with SRNS. The availability of genetic testing, combined with the significant phenotypic variability of monogenic SRNS, poses unique challenges for clinicians when directing genetic testing. This highlights the need for clear clinical guidelines that provide a systematic approach for mutational screening in SRNS. The likelihood of identifying a causative mutation is inversely related to age at disease onset and is increased with a positive family history or the presence of extra-renal manifestations. An unequivocal molecular diagnosis could allow for a personalised treatment approach with weaning of immunosuppressive therapy, avoidance of renal biopsy and provision of accurate, well-informed genetic counselling. Identification of novel causative mutations will continue to unravel the pathogenic mechanisms of glomerular disease and provide new insights into podocyte biology and glomerular function.
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40
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Rood IM, Deegens JKJ, Lugtenberg D, Bongers EMHF, Wetzels JFM. Nephrotic Syndrome With Mutations in NPHS2: The Role of R229Q and Implications for Genetic Counseling. Am J Kidney Dis 2018; 73:400-403. [PMID: 30241959 DOI: 10.1053/j.ajkd.2018.06.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 06/28/2018] [Indexed: 12/17/2022]
Abstract
Mutations in the NPHS2 gene, which encodes the podocyte slit diaphragm protein podocin, cause autosomal recessive steroid-resistant nephrotic syndrome (Online Mendelian Inheritance in Man [OMIM] #600995). Basic research and clinical studies have provided important insights about genotype-phenotype correlations. This knowledge allows personalized genetic (risk) counseling and should lead to changes in the advice given to patients. A patient who carries the R229Q variant (which has a high allele frequency of 3.7% in the European population) in combination with a pathogenic variant in exon 7 or 8 is at high risk for developing nephrotic syndrome that may not manifest before adulthood, whereas a patient with 2 pathogenic variants will develop congenital or childhood-onset nephrotic syndrome. In contrast, a patient who carries the R229Q variant in combination with a pathogenic variant in exons 1 to 6 is unlikely to develop nephrotic syndrome. In this article, we review the emerging knowledge about the NPHS2 gene and translate these findings from the bench to practical advice for the clinical bedside.
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Affiliation(s)
- Ilse M Rood
- Department of Nephrology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, the Netherlands.
| | - Jeroen K J Deegens
- Department of Nephrology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, the Netherlands
| | - Dorien Lugtenberg
- Department of Human Genetics, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, the Netherlands
| | - Ernie M H F Bongers
- Department of Human Genetics, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, the Netherlands
| | - Jack F M Wetzels
- Department of Nephrology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, the Netherlands
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Weng Z, Shang Y, Ji Z, Ye F, Lin L, Zhang R, Zhu J. Structural Basis of Highly Specific Interaction between Nephrin and MAGI1 in Slit Diaphragm Assembly and Signaling. J Am Soc Nephrol 2018; 29:2362-2371. [PMID: 30006415 PMCID: PMC6115659 DOI: 10.1681/asn.2017121275] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 06/19/2018] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The slit diaphragm is a specialized adhesion junction between opposing podocytes, establishing the final filtration barrier that prevents passage of proteins from the capillary lumen into the urinary space. Nephrin, the key structural and signaling adhesion molecule expressed in the slit diaphragm, contains an evolutionally conserved, atypical PDZ-binding motif (PBM) reported to bind to a variety of proteins in the slit diaphragm. Several mutations in NPHS1 (the gene encoding nephrin) that result in nephrin lacking an intact PBM are associated with glomerular diseases. However, the molecular basis of nephrin-PBM-mediated protein complexes is still unclear. METHODS Using a combination of biochemic, biophysic, and cell biologic approaches, we systematically investigated the interactions between nephrin-PBM and PDZ domain-containing proteins in the slit diaphragm. RESULTS We found that nephrin-PBM specifically binds to one member of the membrane-associated guanylate kinase family of scaffolding proteins, MAGI1, but not to another, MAGI2. The complex structure of MAGI1-PDZ3/nephrin-PBM reveals that the Gly at the -3 position of nephrin-PBM is the determining feature for MAGI1-PDZ3 recognition, which sharply contrasts with the typical PDZ/PBM binding mode. A single gain-of-function mutation within MAGI2 enabled nephrin-PBM binding. In addition, using our structural analysis, we developed a highly efficient inhibitory peptide capable of specifically blocking the nephrin/MAGI1 interaction. CONCLUSIONS MAGI1 interacts with nephrin-PBM with exquisite specificity. A newly developed, potent inhibitory peptide that blocks this interaction may be useful for future functional investigations in vivo. Our findings also provide possible explanations for the diseases caused by NPHS1 mutations.
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Affiliation(s)
- Zhuangfeng Weng
- State Key Laboratory of Molecular Biology, Shanghai Science Research Center, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China;,School of Life Science and Technology, ShanghaiTech University, Shanghai, China; and
| | - Yuan Shang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, and
| | - Zeyang Ji
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, and
| | - Fei Ye
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, and,Center of Systems Biology and Human Health, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Lin Lin
- State Key Laboratory of Molecular Biology, Shanghai Science Research Center, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Rongguang Zhang
- State Key Laboratory of Molecular Biology, Shanghai Science Research Center, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China;,School of Life Science and Technology, ShanghaiTech University, Shanghai, China; and
| | - Jinwei Zhu
- State Key Laboratory of Molecular Biology, Shanghai Science Research Center, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
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42
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Fan J, Fu R, Ren F, He J, Wang S, Gou M. A case report of CRB2 mutation identified in a Chinese boy with focal segmental glomerulosclerosis. Medicine (Baltimore) 2018; 97:e12362. [PMID: 30212996 PMCID: PMC6156060 DOI: 10.1097/md.0000000000012362] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
RATIONALE Focal segmental glomerulosclerosis (FSGS) is a common disease resulting in end-stage renal disease. The incidence of FSGS is increasing in Western countries. The clinical manifestations include proteinuria, hypoproteinemia, oedema, and hypertension. Single-gene heritable mutations are considered to be the source of FSGS pathogenicity according to recent in-depth studies on the pathogenesis. Here, we first reported the case of a Chinese boy whose histology presented with FSGS caused by a compound heterozygous mutation. PATIENT CONCERNS A 7-year-old Chinese boy was repeatedly admitted to our hospital for fever, cough, and proteinuria since he was 1.6 years old. DIAGNOSES FSGS was identified by renal biopsy. Whole exome sequencing (WES) showed that a novel mutation of crumbs homolog 2 (CRB2) was identified in a Chinese boy with FSGS. INTERVENTIONS Patient was treated with low-dose corticosteroid and mycophenolate mofetil for maintenance therapy. OUTCOMES At last follow-up, protein (+∼++) was observed in his urinalysis. LESSONS We identified a novel mutation of CRB2 in a Chinese boy with FSGS that had never been described in a previous report. These findings suggested that mutations in recessive disease genes are more frequent among early-onset disease.
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43
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Empitu MA, Kadariswantiningsih IN, Aizawa M, Asanuma K. MAGI-2 and scaffold proteins in glomerulopathy. Am J Physiol Renal Physiol 2018; 315:F1336-F1344. [PMID: 30110567 DOI: 10.1152/ajprenal.00292.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In many cells and tissues, including the glomerular filtration barrier, scaffold proteins are critical in optimizing signal transduction by enhancing structural stability and functionality of their ligands. Recently, mutations in scaffold protein membrane-associated guanylate kinase inverted 2 (MAGI-2) encoding gene were identified among the etiology of steroid-resistant nephrotic syndrome. MAGI-2 interacts with core proteins of multiple pathways, such as transforming growth factor-β signaling, planar cell polarity pathway, and Wnt/β-catenin signaling in podocyte and slit diaphragm. Through the interaction with its ligand, MAGI-2 modulates the regulation of apoptosis, cytoskeletal reorganization, and glomerular development. This review aims to summarize recent findings on the role of MAGI-2 and some other scaffold proteins, such as nephrin and synaptopodin, in the underlying mechanisms of glomerulopathy.
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Affiliation(s)
- Maulana A Empitu
- Department of Nephrology, Graduate School of Medicine, Chiba University , Chiba , Japan.,Department of Pharmacology and Therapeutics, Faculty of Medicine, Universitas Airlangga , Surabaya , Indonesia
| | - Ika N Kadariswantiningsih
- Department of Nephrology, Graduate School of Medicine, Chiba University , Chiba , Japan.,Department of Medical Microbiology, Faculty of Medicine, Universitas Airlangga , Surabaya , Indonesia
| | - Masashi Aizawa
- Department of Nephrology, Graduate School of Medicine, Chiba University , Chiba , Japan
| | - Katsuhiko Asanuma
- Department of Nephrology, Graduate School of Medicine, Chiba University , Chiba , Japan
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44
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Hermle T, Schneider R, Schapiro D, Braun DA, van der Ven AT, Warejko JK, Daga A, Widmeier E, Nakayama M, Jobst-Schwan T, Majmundar AJ, Ashraf S, Rao J, Finn LS, Tasic V, Hernandez JD, Bagga A, Jalalah SM, El Desoky S, Kari JA, Laricchia KM, Lek M, Rehm HL, MacArthur DG, Mane S, Lifton RP, Shril S, Hildebrandt F. GAPVD1 and ANKFY1 Mutations Implicate RAB5 Regulation in Nephrotic Syndrome. J Am Soc Nephrol 2018; 29:2123-2138. [PMID: 29959197 PMCID: PMC6065084 DOI: 10.1681/asn.2017121312] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/24/2018] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of CKD. The discovery of monogenic causes of SRNS has revealed specific pathogenetic pathways, but these monogenic causes do not explain all cases of SRNS. METHODS To identify novel monogenic causes of SRNS, we screened 665 patients by whole-exome sequencing. We then evaluated the in vitro functional significance of two genes and the mutations therein that we discovered through this sequencing and conducted complementary studies in podocyte-like Drosophila nephrocytes. RESULTS We identified conserved, homozygous missense mutations of GAPVD1 in two families with early-onset NS and a homozygous missense mutation of ANKFY1 in two siblings with SRNS. GAPVD1 and ANKFY1 interact with the endosomal regulator RAB5. Coimmunoprecipitation assays indicated interaction between GAPVD1 and ANKFY1 proteins, which also colocalized when expressed in HEK293T cells. Silencing either protein diminished the podocyte migration rate. Compared with wild-type GAPVD1 and ANKFY1, the mutated proteins produced upon ectopic expression of GAPVD1 or ANKFY1 bearing the patient-derived mutations exhibited altered binding affinity for active RAB5 and reduced ability to rescue the knockout-induced defect in podocyte migration. Coimmunoprecipitation assays further demonstrated a physical interaction between nephrin and GAPVD1, and immunofluorescence revealed partial colocalization of these proteins in rat glomeruli. The patient-derived GAPVD1 mutations reduced nephrin-GAPVD1 binding affinity. In Drosophila, silencing Gapvd1 impaired endocytosis and caused mistrafficking of the nephrin ortholog. CONCLUSIONS Mutations in GAPVD1 and probably in ANKFY1 are novel monogenic causes of NS. The discovery of these genes implicates RAB5 regulation in the pathogenesis of human NS.
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Affiliation(s)
- Tobias Hermle
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
- Renal Division, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ronen Schneider
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - David Schapiro
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Daniela A Braun
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Amelie T van der Ven
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jillian K Warejko
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ankana Daga
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Eugen Widmeier
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Makiko Nakayama
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Tilman Jobst-Schwan
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Amar J Majmundar
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Shazia Ashraf
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jia Rao
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Laura S Finn
- Department of Pathology, Seattle Children's Hospital, University of Washington, Seattle, Washington
| | - Velibor Tasic
- Department of Pediatric Nephrology, Medical Faculty Skopje, University Children's Hospital, Skopje, Macedonia
| | - Joel D Hernandez
- Department of Pediatric Nephrology, Providence Sacred Heart Medical Center and Children's Hospital, Spokane, Washington
| | - Arvind Bagga
- Division of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | | | - Sherif El Desoky
- Pediatric Nephrology Center of Excellence and Pediatric Department, Faculty of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
| | - Jameela A Kari
- Pediatric Nephrology Center of Excellence and Pediatric Department, Faculty of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
| | - Kristen M Laricchia
- Broad Center for Mendelian Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts
| | - Monkol Lek
- Broad Center for Mendelian Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts
| | - Heidi L Rehm
- Broad Center for Mendelian Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts
| | - Daniel G MacArthur
- Broad Center for Mendelian Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts
| | - Shrikant Mane
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut; and
| | - Richard P Lifton
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut; and
- Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, New York
| | - Shirlee Shril
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Friedhelm Hildebrandt
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts;
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45
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A kidney-disease gene panel allows a comprehensive genetic diagnosis of cystic and glomerular inherited kidney diseases. Kidney Int 2018; 94:363-371. [DOI: 10.1016/j.kint.2018.02.027] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 02/09/2018] [Accepted: 02/15/2018] [Indexed: 12/14/2022]
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46
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Hochapfel F, Denk L, Maaßen C, Zaytseva Y, Rachel R, Witzgall R, Krahn MP. Electron microscopy of
Drosophila
garland cell nephrocytes: Optimal preparation, immunostaining and STEM tomography. J Cell Biochem 2018; 119:8011-8021. [DOI: 10.1002/jcb.26702] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/23/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Florian Hochapfel
- Molecular and Cellular AnatomyUniversity of RegensburgRegensburgGermany
- Medizinische Klinik und Poliklinik DUniversitätsklinikum MünsterMünsterGermany
| | - Lucia Denk
- Molecular and Cellular AnatomyUniversity of RegensburgRegensburgGermany
| | - Christine Maaßen
- Molecular and Cellular AnatomyUniversity of RegensburgRegensburgGermany
| | - Yulia Zaytseva
- Molecular and Cellular AnatomyUniversity of RegensburgRegensburgGermany
| | - Reinhard Rachel
- Molecular and Cellular AnatomyUniversity of RegensburgRegensburgGermany
| | - Ralph Witzgall
- Molecular and Cellular AnatomyUniversity of RegensburgRegensburgGermany
| | - Michael P. Krahn
- Molecular and Cellular AnatomyUniversity of RegensburgRegensburgGermany
- Medizinische Klinik und Poliklinik DUniversitätsklinikum MünsterMünsterGermany
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47
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Mutations in six nephrosis genes delineate a pathogenic pathway amenable to treatment. Nat Commun 2018; 9:1960. [PMID: 29773874 PMCID: PMC5958119 DOI: 10.1038/s41467-018-04193-w] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 04/07/2018] [Indexed: 02/06/2023] Open
Abstract
No efficient treatment exists for nephrotic syndrome (NS), a frequent cause of chronic kidney disease. Here we show mutations in six different genes (MAGI2, TNS2, DLC1, CDK20, ITSN1, ITSN2) as causing NS in 17 families with partially treatment-sensitive NS (pTSNS). These proteins interact and we delineate their roles in Rho-like small GTPase (RLSG) activity, and demonstrate deficiency for mutants of pTSNS patients. We find that CDK20 regulates DLC1. Knockdown of MAGI2, DLC1, or CDK20 in cultured podocytes reduces migration rate. Treatment with dexamethasone abolishes RhoA activation by knockdown of DLC1 or CDK20 indicating that steroid treatment in patients with pTSNS and mutations in these genes is mediated by this RLSG module. Furthermore, we discover ITSN1 and ITSN2 as podocytic guanine nucleotide exchange factors for Cdc42. We generate Itsn2-L knockout mice that recapitulate the mild NS phenotype. We, thus, define a functional network of RhoA regulation, thereby revealing potential therapeutic targets. Nephrotic syndrome is the second most common chronic kidney disease but there are no targeted treatment strategies available. Here the authors identify mutations of six genes codifying for proteins involved in cytoskeleton remodelling and modulation of small GTPases in 17 families with nephrotic syndrome.
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48
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Deriving and understanding the risk of post-transplant recurrence of nephrotic syndrome in the light of current molecular and genetic advances. Pediatr Nephrol 2018; 33:2027-2035. [PMID: 29022104 PMCID: PMC6153493 DOI: 10.1007/s00467-017-3793-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 08/22/2017] [Indexed: 12/31/2022]
Abstract
After renal transplantation, recurrence of the original disease is the second most common cause of graft loss, after rejection. The most dramatic manifestation of this phenomenon is in patients with nephrotic syndrome (NS). NS is a descriptive term describing a clinical picture centred on proteinuria arising from damage to the glomerular filtration barrier (GFB). There are many different drivers of that damage, ranging from immune dysregulation to genetic disorders and chronic disease/infections. The main categories in childhood are "idiopathic" (presumed immune mediated) and genetic NS, with further stratification of the idiopathic group according to steroid responses. A significant proportion of patients with NS progress to established renal failure, requiring transplantation, and one of the most difficult clinical scenarios faced by nephrologists is the recurrence of the original disease in up to 50% of patients, usually rapidly post-transplant. This is thought to be the archetypal "circulating factor" disease, in which as yet unknown circulating plasma "factor(s)" in the recipient target the donor kidney. The ability to predict in advance which patients will suffer recurrence would enhance our ability to counsel patients and families, and potentially identify those patients before transplant for tailored immunosuppressive preparation. Until very recently, stratification based on clinical categorisations has been poor in being able to predict those patients in whom disease will recur, and laboratory biomarkers are yet to be adequately refined. However, by mapping our growing understanding of disease mechanisms to clinical phenotypes, and with greatly improved genetic diagnostics, we have made progress in being able to stratify patients more specifically, and allow better predictive algorithms to be developed. Using our knowledge of podocyte biology, circulating factor-induced specific biomarkers are also being tested. This review is aimed at outlining those advances, and suggesting how we can move further forward in both clinical and biological markers of disease type.
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49
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Sen ES, Dean P, Yarram-Smith L, Bierzynska A, Woodward G, Buxton C, Dennis G, Welsh GI, Williams M, Saleem MA. Clinical genetic testing using a custom-designed steroid-resistant nephrotic syndrome gene panel: analysis and recommendations. J Med Genet 2017; 54:795-804. [PMID: 28780565 PMCID: PMC5740557 DOI: 10.1136/jmedgenet-2017-104811] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 06/27/2017] [Accepted: 06/29/2017] [Indexed: 01/16/2023]
Abstract
BACKGROUND There are many single-gene causes of steroid-resistant nephrotic syndrome (SRNS) and the list continues to grow rapidly. Prompt comprehensive diagnostic testing is key to realising the clinical benefits of a genetic diagnosis. This report describes a bespoke-designed, targeted next-generation sequencing (NGS) diagnostic gene panel assay to detect variants in 37 genes including the ability to identify copy number variants (CNVs). METHODS This study reports results of 302 patients referred for SRNS diagnostic gene panel analysis. Phenotype and clinical impact data were collected using a standard proforma. Candidate variants detected by NGS were confirmed by Sanger sequencing/Multiplex Ligation-dependent Probe Amplification with subsequent family segregation analysis where possible. RESULTS Clinical presentation was nephrotic syndrome in 267 patients and suspected Alport syndrome (AS) in 35. NGS panel testing determined a likely genetic cause of disease in 44/220 (20.0%) paediatric and 10/47 (21.3%) adult nephrotic cases, and 17/35 (48.6%) of haematuria/AS patients. Of 71 patients with genetic disease, 32 had novel pathogenic variants without a previous disease association including two with deletions of one or more exons of NPHS1 or NPHS2. CONCLUSION Gene panel testing provides a genetic diagnosis in a significant number of patients presenting with SRNS or suspected AS. It should be undertaken at an early stage of the care pathway and include the ability to detect CNVs as an emerging mechanism for genes associated with this condition. Use of clinical genetic testing after diagnosis of SRNS has the potential to stratify patients and assist decision-making regarding management.
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Affiliation(s)
- Ethan S Sen
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
- Bristol Royal Hospital for Children, Bristol, UK
| | - Philip Dean
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, UK
| | | | | | - Geoff Woodward
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, UK
| | - Chris Buxton
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, UK
| | - Gemma Dennis
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, UK
| | - Gavin I Welsh
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Maggie Williams
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, UK
| | - Moin A Saleem
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
- Bristol Royal Hospital for Children, Bristol, UK
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50
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Shirata N, Ihara KI, Yamamoto-Nonaka K, Seki T, Makino SI, Oliva Trejo JA, Miyake T, Yamada H, Campbell KN, Nakagawa T, Mori K, Yanagita M, Mundel P, Nishimori K, Asanuma K. Glomerulosclerosis Induced by Deficiency of Membrane-Associated Guanylate Kinase Inverted 2 in Kidney Podocytes. J Am Soc Nephrol 2017; 28:2654-2669. [PMID: 28539383 DOI: 10.1681/asn.2016121356] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/03/2017] [Indexed: 11/03/2022] Open
Abstract
Membrane-associated guanylate kinase inverted 2 (MAGI-2) is a component of the slit diaphragm (SD) of glomerular podocytes. Here, we investigated the podocyte-specific function of MAGI-2 using newly generated podocyte-specific MAGI-2-knockout (MAGI-2-KO) mice. Compared with podocytes from wild-type mice, podocytes from MAGI-2-KO mice exhibited SD disruption, morphologic abnormalities of foot processes, and podocyte apoptosis leading to podocyte loss. These pathologic changes manifested as massive albuminuria by 8 weeks of age and glomerulosclerosis and significantly higher plasma creatinine levels at 12 weeks of age; all MAGI-2-KO mice died by 20 weeks of age. Loss of MAGI-2 in podocytes associated with decreased expression and nuclear translocation of dendrin, which is also a component of the SD complex. Dendrin translocates from the SD to the nucleus of injured podocytes, promoting apoptosis. Our coimmunoprecipitation and in vitro reconstitution studies showed that dendrin is phosphorylated by Fyn and dephosphorylated by PTP1B, and that Fyn-induced phosphorylation prevents Nedd4-2-mediated ubiquitination of dendrin. Under physiologic conditions in vivo, phosphorylated dendrin localized at the SDs; in the absence of MAGI-2, dephosphorylated dendrin accumulated in the nucleus. Furthermore, induction of experimental GN in rats led to the downregulation of MAGI-2 expression and the nuclear accumulation of dendrin in podocytes. In summary, MAGI-2 and Fyn protect dendrin from Nedd4-2-mediated ubiquitination and from nuclear translocation, thereby maintaining the physiologic homeostasis of podocytes, and the lack of MAGI-2 in podocytes results in FSGS.
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Affiliation(s)
- Naritoshi Shirata
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharmaceutical Corporation, Toda, Japan
| | - Kan-Ichiro Ihara
- The Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Kanae Yamamoto-Nonaka
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Takuto Seki
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Shin-Ichi Makino
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Juan Alejandro Oliva Trejo
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takafumi Miyake
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroyuki Yamada
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kirk Nicholas Campbell
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York; and
| | - Takahiko Nakagawa
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kiyoshi Mori
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Motoko Yanagita
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Peter Mundel
- Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts
| | - Katsuhiko Nishimori
- The Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Katsuhiko Asanuma
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan; .,Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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