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Atchison DK, O'Connor CL, Menon R, Otto EA, Ganesh SK, Wiggins RC, Smrcka AV, Bitzer M. Hypertension induces glomerulosclerosis in phospholipase C-ε1 deficiency. Am J Physiol Renal Physiol 2020; 318:F1177-F1187. [PMID: 32223311 DOI: 10.1152/ajprenal.00541.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Loss-of-function mutations in phospholipase C-ε1 (PLCE1) have been detected in patients with nephrotic syndrome, but other family members with the same mutation were asymptomatic, suggesting additional stressor are required to cause the full phenotype. Consistent with these observations, we determined that global Plce1-deficient mice have histologically normal glomeruli and no albuminuria at baseline. Angiotensin II (ANG II) is known to induce glomerular damage in genetically susceptible individuals. Therefore, we tested whether ANG II enhances glomerular damage in Plce1-deficient mice. ANG II increased blood pressure equally in Plce1-deficient and wild-type littermates. Additionally, it led to 20-fold increased albuminuria and significantly more sclerotic glomeruli in Plce1-deficient mice compared with wild-type littermates. Furthermore, Plce1-deficient mice demonstrated diffuse mesangial expansion, podocyte loss, and focal podocyte foot process effacement. To determine whether these effects are mediated by hypertension and hyperfiltration, rather than directly through ANG II, we raised blood pressure to a similar level using DOCA + salt + uninephrectomy and norepinephrine. This caused a fivefold increase in albuminuria in Plce1-deficient mice and a significant increase in the number of sclerotic glomeruli. Consistent with previous findings in mice, we detected strong PLCE1 transcript expression in podocytes using single cell sequencing of human kidney tissue. In hemagglutinin-tagged Plce1 transgenic mice, Plce1 was detected in podocytes and also in glomerular arterioles using immunohistochemistry. Our data demonstrate that Plce1 deficiency in mice predisposes to glomerular damage secondary to hypertensive insults.
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Affiliation(s)
- Douglas K Atchison
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Christopher L O'Connor
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Rajasree Menon
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Edgar A Otto
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Santhi K Ganesh
- Cardiovascular Division, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Roger C Wiggins
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Alan V Smrcka
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
| | - Markus Bitzer
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
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Abstract
PURPOSE OF REVIEW The purpose of this review is to emphasize that single gene disorders are an important and sometimes unrecognized cause of progressive chronic kidney disease. We provide an overview of the benefits of making a genetic diagnosis, the currently available genetic testing methods and examples of diseases illustrating the impact of a genetic diagnosis. RECENT FINDINGS Although there are now a number of monogenic renal diseases, only a few, such as autosomal dominant polycystic kidney disease (ADPKD), are generally diagnosable without genetic testing. Complicating clinical diagnosis is that many diseases that classically have characteristic renal or extrarenal findings, often present with an incomplete or overlapping phenotype that requires additional testing to be uncovered. Advances in sequencing technology and bioinformatic processing now give us the ability to screen the entire human genome or exome or an organ-limited subset of genes quickly and inexpensively permitting the unbiased interrogation of hundreds of genes, thus removing the need for precision in clinical diagnosis prior to testing. SUMMARY We provide an overview of the principal phenotypes seen in chronic kidney disease with a focus on the cystic diseases and ciliopathies, the glomerular diseases, disorders of renal development and the tubulointerstitial diseases. In each of these phenotypes, we provide a listing of some of the important genes that have been identified to date, a brief discussion of the clinical diagnosis, the role of genetic testing and the differentiation of distinct genetic disorders from acquired and genetic phenocopies.
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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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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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Schapiro D, Daga A, Lawson JA, Majmundar AJ, Lovric S, Tan W, Warejko JK, Fessi I, Rao J, Airik M, Gee HY, Schneider R, Widmeier E, Hermle T, Ashraf S, Jobst-Schwan T, van der Ven AT, Nakayama M, Shril S, Braun DA, Hildebrandt F. Panel sequencing distinguishes monogenic forms of nephritis from nephrosis in children. Nephrol Dial Transplant 2019; 34:474-485. [PMID: 30295827 DOI: 10.1093/ndt/gfy050] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 01/21/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Alport syndrome (AS) and atypical hemolytic-uremic syndrome (aHUS) are rare forms of chronic kidney disease (CKD) that can lead to a severe decline of renal function. Steroid-resistant nephrotic syndrome (SRNS) is more common than AS and aHUS and causes 10% of childhood-onset CKD. In recent years, multiple monogenic causes of AS, aHUS and SRNS have been identified, but their relative prevalence has yet to be studied together in a typical pediatric cohort of children with proteinuria and hematuria. We hypothesized that identification of causative mutations by whole exome sequencing (WES) in known monogenic nephritis and nephrosis genes would allow distinguishing nephritis from nephrosis in a typical pediatric group of patients with both proteinuria and hematuria at any level. METHODS We therefore conducted an exon sequencing (WES) analysis for 11 AS, aHUS and thrombotic thrombocytopenic purpura-causing genes in an international cohort of 371 patients from 362 families presenting with both proteinuria and hematuria before age 25 years. In parallel, we conducted either WES or high-throughput exon sequencing for 23 SRNS-causing genes in all patients. RESULTS We detected pathogenic mutations in 18 of the 34 genes analyzed, leading to a molecular diagnosis in 14.1% of families (51 of 362). Disease-causing mutations were detected in 3 AS-causing genes (4.7%), 3 aHUS-causing genes (1.4%) and 12 NS-causing genes (8.0%). We observed a much higher mutation detection rate for monogenic forms of CKD in consanguineous families (35.7% versus 10.1%). CONCLUSIONS We present the first estimate of relative frequency of inherited AS, aHUS and NS in a typical pediatric cohort with proteinuria and hematuria. Important therapeutic and preventative measures may result from mutational analysis in individuals with proteinuria and hematuria.
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Affiliation(s)
- David Schapiro
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ankana Daga
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jennifer A Lawson
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Amar J Majmundar
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Svjetlana Lovric
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Weizhen Tan
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jillian K Warejko
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Inés Fessi
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jia Rao
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Merlin Airik
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Heon Yung Gee
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ronen Schneider
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Eugen Widmeier
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Tobias Hermle
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Shazia Ashraf
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Tilman Jobst-Schwan
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Amelie T van der Ven
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Makiko Nakayama
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Shirlee Shril
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Daniela A Braun
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Friedhelm Hildebrandt
- Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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57
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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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Bensimhon AR, Williams AE, Gbadegesin RA. Treatment of steroid-resistant nephrotic syndrome in the genomic era. Pediatr Nephrol 2019; 34:2279-2293. [PMID: 30280213 PMCID: PMC6445770 DOI: 10.1007/s00467-018-4093-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 09/13/2018] [Accepted: 09/18/2018] [Indexed: 12/25/2022]
Abstract
The pathogenesis of steroid-resistant nephrotic syndrome (SRNS) is not completely known. Recent advances in genomics have elucidated some of the molecular mechanisms and pathophysiology of the disease. More than 50 monogenic causes of SRNS have been identified; however, these genes are responsible for only a small fraction of SRNS in outbred populations. There are currently no guidelines for genetic testing in SRNS, but evidence from the literature suggests that testing should be guided by the genetic architecture of the disease in the population. Notably, most genetic forms of SRNS do not respond to current immunosuppressive therapies; however, a small subset of patients with monogenic SRNS will achieve partial or complete remission with specific immunomodulatory agents, presumably due to non-immunosuppressive effects of these agents. We suggest a pragmatic approach to the therapy of genetic SRNS, as there is no evidence-based algorithm for the management of the disease.
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Affiliation(s)
- Adam R. Bensimhon
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA
| | - Anna E. Williams
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA
| | - Rasheed A. Gbadegesin
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA,Department of Medicine, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA,Duke Molecular Physiology Institute, Durham, NC, USA
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59
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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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Morgan CJ, Hedman AC, Li Z, Sacks DB. Endogenous IQGAP1 and IQGAP3 do not functionally interact with Ras. Sci Rep 2019; 9:11057. [PMID: 31363101 PMCID: PMC6667474 DOI: 10.1038/s41598-019-46677-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/28/2019] [Indexed: 02/07/2023] Open
Abstract
The Ras family of small GTPases modulates numerous essential processes. Activating Ras mutations result in hyper-activation of selected signaling cascades, which leads to human diseases. The high frequency of Ras mutations in human malignant neoplasms has led to Ras being a desirable chemotherapeutic target. The IQGAP family of scaffold proteins binds to and regulates multiple signaling molecules, including the Rho family GTPases Rac1 and Cdc42. There are conflicting data in the published literature regarding interactions between IQGAP and Ras proteins. Initial reports showed no binding, but subsequent studies claim associations of IQGAP1 and IQGAP3 with K-Ras and H-Ras, respectively. Therefore, we set out to resolve this controversy. Here we demonstrate that neither endogenous IQGAP1 nor endogenous IQGAP3 binds to the major Ras isoforms, namely H-, K-, and N-Ras. Importantly, Ras activation by epidermal growth factor is not altered when IQGAP1 or IQGAP3 proteins are depleted from cells. These data strongly suggest that IQGAP proteins are not functional interactors of H-, K-, or N-Ras and challenge the rationale for targeting the interaction of Ras with IQGAP for the development of therapeutic agents.
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Affiliation(s)
- Chase J Morgan
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - Andrew C Hedman
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - Zhigang Li
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - David B Sacks
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA.
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61
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Kalantari S, Naji M, Nafar M, Yazdani-Kachooei H, Borumandnia N, Parvin M. Chondroitin sulfate degradation and eicosanoid metabolism pathways are impaired in focal segmental glomerulosclerosis: Experimental confirmation of an in silico prediction. ACTA ACUST UNITED AC 2019; 9:89-95. [PMID: 31334040 PMCID: PMC6637215 DOI: 10.15171/bi.2019.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/16/2018] [Accepted: 12/22/2018] [Indexed: 11/09/2022]
Abstract
Introduction: Focal segmental glomerulosclerosis (FSGS), the most common primary glomerular disease, is a diverse clinical entity that occurs after podocyte injury. Although numerous studies have suggested molecular pathways responsible for the development of FSGS, many still remain unknown about its pathogenic mechanisms. Two important pathways were predicted as candidates for the pathogenesis of FSGS in our previous in silico analysis, whom we aim to confirm experimentally in the present study. Methods: The expression levels of 4 enzyme genes that are representative of "chondroitin sulfate degradation" and "eicosanoid metabolism" pathways were investigated in the urinary sediments of biopsy-proven FSGS patients and healthy subjects using real-time polymerase chain reaction (RT-PCR). These target genes were arylsulfatase, hexosaminidase, cyclooxygenase-2 (COX-2), and prostaglandin I2 synthase. The patients were sub-divided into 2 groups based on the range of proteinuria and glomerular filtration rate and were compared for variation in the expression of target genes. Correlation of target genes with clinical and pathological characteristics of the disease was calculated and receiver operating characteristic (ROC) analysis was performed. Results: A combined panel of arylsulfatase, hexosaminidase, and COX-2 improved the diagnosis of FSGS by 76%. Hexosaminidase was correlated with the level of proteinuria, while COX-2 was correlated with interstitial inflammation and serum creatinine level in the disease group. Conclusion: Our data supported the implication of these target genes and pathways in the pathogenesis of FSGS. In addition, these genes can be considered as non-invasive biomarkers for FSGS.
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Affiliation(s)
- Shiva Kalantari
- Chronic Kidney Disease Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Naji
- Urology-Nephrology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohsen Nafar
- Urology-Nephrology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hootan Yazdani-Kachooei
- Department of Biology, Faculty of Basic Sciences, Islamic Azad University, Science and Research Branch, Tehran, Iran
| | - Nasrin Borumandnia
- Urology-Nephrology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahmoud Parvin
- Department of Pathology, Shahid Labbafinejad Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Shimizu M, Irabu H, Kaneda H, Ohta K, Nozu K. Familial focal segmental glomerulosclerosis with PLCE1 mutation in siblings. Pediatr Int 2019; 61:726-727. [PMID: 31359539 DOI: 10.1111/ped.13870] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 02/26/2019] [Accepted: 04/04/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Masaki Shimizu
- Department of Pediatrics, School of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hitoshi Irabu
- Department of Pediatrics, School of Medicine, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hisashi Kaneda
- Department of Pediatrics, Kanazawa Medical Center, Kanazawa, Ishikawa, Japan
| | - Kazuhide Ohta
- Department of Pediatrics, Komatsu Municipal Hospital, Komatsu, Ishikawa, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
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Zeng M, Liu J, Yang W, Zhang S, Liu F, Dong Z, Peng Y, Sun L, Xiao L. Identification of key biomarkers in diabetic nephropathy via bioinformatic analysis. J Cell Biochem 2019; 120:8676-8688. [PMID: 30485525 DOI: 10.1002/jcb.28155] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 11/09/2018] [Indexed: 01/24/2023]
Abstract
Diabetic nephropathy (DN) is a major cause of end-stage renal disease. Although intense efforts have been made to elucidate the pathogenesis, the molecular mechanisms of DN remain to be clarified. To identify the candidate genes in the progression of DN, microarray datasets GSE30122, GSE30528, and GSE47183 were downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) were identified, and function enrichment analyses were performed. The protein-protein interaction network was constructed and the module analysis was performed using the Search Tool for the Retrieval of Interacting Genes and Cytoscape. A total of 61 DEGs were identified. The enriched functions and pathways of the DEGs included glomerulus development, extracellular exosome, collagen binding, and the PI3K-Akt signaling pathway. Fifteen hub genes were identified and biological process analysis revealed that these genes were mainly enriched in acute inflammatory response, inflammatory response, and blood vessel development. Correlation analysis between unexplored hub genes and clinical features of DN suggested that COL6A3, MS4A6A,PLCE1, TNNC1, TNNI1, TNN2, and VSIG4 may involve in the progression of DN. In conclusion, DEGs and hub genes identified in this study may deepen our understanding of molecular mechanisms underlying the progression of DN, and provide candidate targets for diagnosis and treatment of DN.
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Affiliation(s)
- Mengru Zeng
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jialu Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wenxia Yang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shumin Zhang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Fuyou Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zheng Dong
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University and Charlie Norwood VA Medical Center, Augusta, Georgia
| | - Youming Peng
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lin Sun
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Li Xiao
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
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64
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Sahu SN, Moharana M, Sahu R, Pattanayak SK. Impact of mutation on podocin protein involved in type 2 nephrotic syndrome: Insights into docking and molecular dynamics simulation study. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.02.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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65
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Outtandy P, Russell C, Kleta R, Bockenhauer D. Zebrafish as a model for kidney function and disease. Pediatr Nephrol 2019; 34:751-762. [PMID: 29502161 PMCID: PMC6424945 DOI: 10.1007/s00467-018-3921-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 12/12/2017] [Accepted: 12/12/2017] [Indexed: 12/31/2022]
Abstract
Kidney disease is a global problem with around three million people diagnosed in the UK alone and the incidence is rising. Research is critical to develop better treatments. Animal models can help to better understand the pathophysiology behind the various kidney diseases and to screen for therapeutic compounds, but the use especially of mammalian models should be minimised in the interest of animal welfare. Zebrafish are increasingly used, as they are genetically tractable and have a basic renal anatomy comparable to mammalian kidneys with glomerular filtration and tubular filtration processing. Here, we discuss how zebrafish have advanced the study of nephrology and the mechanisms underlying kidney disease.
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Affiliation(s)
- Priya Outtandy
- Centre for Nephrology, Royal Free Hospital/Medical School, University College London, 1. Floor, Room 1.7007, Rowland Hill Street, London, NW3 2PF, UK
- Department of Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London, NW1 0TU, UK
| | - Claire Russell
- Department of Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London, NW1 0TU, UK
| | - Robert Kleta
- Centre for Nephrology, Royal Free Hospital/Medical School, University College London, 1. Floor, Room 1.7007, Rowland Hill Street, London, NW3 2PF, UK.
| | - Detlef Bockenhauer
- Centre for Nephrology, Royal Free Hospital/Medical School, University College London, 1. Floor, Room 1.7007, Rowland Hill Street, London, NW3 2PF, UK
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66
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The Role of p.Ser1105Ser (in NPHS1 Gene) and p.Arg548Leu (in PLCE1 Gene) with Disease Status of Vietnamese Patients with Congenital Nephrotic Syndrome: Benign or Pathogenic? ACTA ACUST UNITED AC 2019; 55:medicina55040102. [PMID: 31013750 PMCID: PMC6524047 DOI: 10.3390/medicina55040102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 04/11/2019] [Accepted: 04/11/2019] [Indexed: 11/20/2022]
Abstract
Background and Objectives: Congenital nephrotic syndrome (CNS), a genetic disease caused by mutations in genes on autosomes, usually occurs in the first three months after birth. A number of genetic mutations in genes, which encode for the components of the glomerular filtration barrier have been identified. We investigated mutations in NPHS1, NPHS2, PLCE1 (NPHS3), and WT1 genes that relate to the disease in Vietnamese patients. Materials and Methods: We performed genetic analysis of two unrelated patients, who were diagnosed with CNS in the Vietnam National Children’s Hospital with different disease status. The entire coding region and adjacent splice sites of these genes were amplified and sequenced using the Sanger method. The sequencing data were analyzed and compared with the NPHS1, NPHS2, PLCE1, and WT1 gene sequences published in Ensembl (ENSG00000161270, ENSG00000116218, ENSG00000138193, and ENSG00000184937, respectively) using BioEdit software to detect mutations. Results: We detected a new variant p.Ser607Arg and two other (p.Glu117Lys and p.Ser1105Ser) in the NPHS1 gene, as well as two variants (p.Arg548Leu, p.Pro1575Arg) in the PLCE1 gene. No mutations were detected in the NPHS2 and WT1 genes. Patient 1, who presented a heterozygous genotype of p.Ser1105Ser and p.Arg548Leu had a mild disease status but patient 2, who presented a homozygous genotype of these alleles, had a severe phenotype. Conclusions: These results suggest that variants p.Ser1105Ser (in NPHS1 gene) and p.Arg548Leu (in PLCE1 gene) in the homozygous form might play a role in the development of the disease in patients.
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67
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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: 10] [Impact Index Per Article: 2.0] [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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68
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Onoufriadis A, Nanda A, Sheriff A, Tomita K, Gomaa NS, Simpson MA, McGrath JA. Consanguinity and Double Recessive Gene Pathology: Cutis Laxa (PYCR1) and Nephrotic Syndrome (PLCE1). JAMA Dermatol 2019; 155:257-259. [PMID: 30586144 DOI: 10.1001/jamadermatol.2018.4665] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Alexandros Onoufriadis
- St John's Institute of Dermatology, School of Basic and Medical Biosciences, King's College London, London, England
| | - Arti Nanda
- As'ad Al-Hamad Dermatology Center, Kuwait
| | - Adam Sheriff
- St John's Institute of Dermatology, School of Basic and Medical Biosciences, King's College London, London, England
| | - Kenji Tomita
- St John's Institute of Dermatology, School of Basic and Medical Biosciences, King's College London, London, England
| | - Nesrin S Gomaa
- St John's Institute of Dermatology, School of Basic and Medical Biosciences, King's College London, London, England
| | - Michael A Simpson
- Department of Medical and Molecular Genetics, School of Basic and Medical Biosciences, King's College London, Guy's Hospital, London SE1 9RT, England
| | - John A McGrath
- St John's Institute of Dermatology, School of Basic and Medical Biosciences, King's College London, London, England
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69
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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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70
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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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71
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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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72
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Association of Exposure to Fine-Particulate Air Pollution and Acidic Gases with Incidence of Nephrotic Syndrome. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15122860. [PMID: 30558173 PMCID: PMC6313436 DOI: 10.3390/ijerph15122860] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/29/2018] [Accepted: 12/12/2018] [Indexed: 01/15/2023]
Abstract
Background: Air pollution has been associated with autoimmune diseases. Nephrotic syndrome is a clinical manifestation of immune-mediated glomerulopathy. However, the association between nephrotic syndrome and air pollution constituents remains unknown. We conducted this nationwide retrospective study to investigate the association between PM2.5 and nephrotic syndrome. Methods: We used the Longitudinal Health Insurance Database (LHID) and the Taiwan Air Quality-Monitoring Database (TAQMD). We combined and stratified the LHID and the TAQMD data by residential areas of insurants linked to nearby air quality-monitoring stations. Air pollutant concentrations were grouped into four levels based on quartile. Univariable and multivariable Cox proportional hazard regression models were applied. Findings: Relative to Q1-level SO₂, subjects exposed to the Q4 level were associated with a 2.00-fold higher risk of nephrotic syndrome (adjusted HR = 2.00, 95% CI = 1.66⁻2.41). In NOx, relative to Q1 NOx concentrations, the adjusted HRs of nephrotic syndrome risk were 1.53 (95% CI = 1.23⁻1.91), 1.30 (95% CI = 1.03⁻1.65), and 2.08 (95% CI = 1.69⁻2.56) for Q2, Q3, and Q4 levels, respectively. The results revealed an increasing trend for nephrotic syndrome risk correlating with increasing levels of NO, NO₂, and PM2.5 concentrations. Interpretation: High concentrations of PM2.5, NO, NO₂, and SO₂ are associated with increased risk of nephrotic syndrome.
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73
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Liu Y, Shi Y, Ren R, Xie J, Wang W, Chen N. Advanced therapeutics in focal and segmental glomerulosclerosis. Nephrology (Carlton) 2018; 23 Suppl 4:57-61. [PMID: 30298667 DOI: 10.1111/nep.13463] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Yunzi Liu
- Department of Nephrology; Ruijin Hospital, Institute of Nephrology, Shanghai Jiao Tong University School of Medicine; Shanghai China
| | - Yifan Shi
- Department of Nephrology; Ruijin Hospital, Institute of Nephrology, Shanghai Jiao Tong University School of Medicine; Shanghai China
| | - Rong Ren
- Department of Nephrology; Ruijin Hospital, Institute of Nephrology, Shanghai Jiao Tong University School of Medicine; Shanghai China
| | - Jingyuan Xie
- Department of Nephrology; Ruijin Hospital, Institute of Nephrology, Shanghai Jiao Tong University School of Medicine; Shanghai China
| | - Weiming Wang
- Department of Nephrology; Ruijin Hospital, Institute of Nephrology, Shanghai Jiao Tong University School of Medicine; Shanghai China
| | - Nan Chen
- Department of Nephrology; Ruijin Hospital, Institute of Nephrology, Shanghai Jiao Tong University School of Medicine; Shanghai China
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74
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Hashmi JA, Safar RA, Afzal S, Albalawi AM, Abdu-Samad F, Iqbal Z, Basit S. Whole exome sequencing identification of a novel insertion mutation in the phospholipase C ε‑1 gene in a family with steroid resistant inherited nephrotic syndrome. Mol Med Rep 2018; 18:5095-5100. [PMID: 30280192 DOI: 10.3892/mmr.2018.9528] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 03/27/2018] [Indexed: 11/05/2022] Open
Abstract
Nephrotic syndrome (NS) represents a heterogeneous group of kidney disorders characterized by excessive proteinuria, hypoalbuminemia and edema. Defects in the filtration barrier of the glomeruli results in the development of NS. The genetic cause of NS remains to be fully elucidated. However, previous studies based on positional cloning of genes mutated in NS have provided limited insight into the pathogenesis of this disease. Mutations in phospholipase C ε‑1 (PLCE1) have been reported as a cause of early onset NS characterized by histology of diffuse mesangial sclerosis. In the present study, the underlying cause of NS in a consanguineous family was identified. Clinical and molecular aspects of a consanguineous Saudi family comprised of five individuals with steroid resistant NS were examined. Seven healthy individuals from the same family were also studied. Whole exome sequencing (WES) was performed to detect the genetic defect underlying NS. WES identified a homozygous novel insertion mutation (c.6272_6273insT) in the PLCE1 gene. Pedigree and segregation analysis confirmed an autosomal recessive inheritance pattern. This mutation may result in a bi‑allelic loss of the C‑terminal Ras‑associating domain in PLCE1 that results in NS. The present study expanded the mutational spectrum of PLCE1 in NS. In addition, the present study provided further evidence that supports the important involvement of PLCE1 in the physiological function of the glomerular filtration barrier.
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Affiliation(s)
- Jamil Amjad Hashmi
- Center for Genetics and Inherited Diseases, Taibah University, Medina 42318, Kingdom of Saudi Arabia
| | - Ramziah Ahmed Safar
- Department of Nephrology, Madinah Maternity and Children Hospital, Medina 42319, Kingdom of Saudi Arabia
| | - Sibtain Afzal
- Prince Naif Centre for Immunology Research, College of Medicine, King Khalid University Hospital, King Saud University, Riyadh 12372, Kingdom of Saudi Arabia
| | - Alia M Albalawi
- Center for Genetics and Inherited Diseases, Taibah University, Medina 42318, Kingdom of Saudi Arabia
| | - Feroz Abdu-Samad
- Center for Genetics and Inherited Diseases, Taibah University, Medina 42318, Kingdom of Saudi Arabia
| | - Zafar Iqbal
- College of Applied Medical Sciences, National Guard Health Affairs, Al‑Ahsa 36428, Kingdom of Saudi Arabia
| | - Sulman Basit
- Center for Genetics and Inherited Diseases, Taibah University, Medina 42318, Kingdom of Saudi Arabia
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75
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Use of genomic and functional analysis to characterize patients with steroid-resistant nephrotic syndrome. Pediatr Nephrol 2018; 33:1741-1750. [PMID: 29982877 DOI: 10.1007/s00467-018-3995-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 06/06/2018] [Accepted: 06/07/2018] [Indexed: 01/09/2023]
Abstract
BACKGROUND Children with genetic causes of steroid-resistant nephrotic syndrome (SRNS) usually do well after renal transplantation, while some with idiopathic SRNS show recurrence due to a putative podocyte-toxic factor. Distinguishing different forms of SRNS based on clinical criteria has been difficult. The aim of our study was to test a novel approach that allows categorization of patients into clinically useful subgroups. METHODS Seventeen patients with clinically confirmed SRNS were analyzed by next-generation sequencing (NGS) of 37 known SRNS genes and a functional assay of cultured human podocytes, which indirectly tests for toxicity of patients' sera by evidenced loss of podocyte focal adhesion complex (FAC) number. RESULTS We identified a pathogenic mutation in seven patients (41%). Sera from patients with monogenic SRNS caused mild loss of FAC number down to 73% compared to untreated controls, while sera from seven of the remaining ten patients with idiopathic SRNS caused significant FAC number loss to 43% (non-overlapping difference 30%, 95% CI 26-36%, P < 0.001). All patients with recurrent SRNS (n = 4) in the graft showed absence of podocyte gene mutations but significant FAC loss. Three patients had no mutation nor serum podocyte toxicity. CONCLUSIONS Our approach allowed categorization of patients into three subgroups: (1) patients with monogenic SRNS; (2) patients with idiopathic SRNS and marked serum podocyte toxicity; and (3) patients without identifiable genetic cause nor evidence of serum podocyte toxicity. Post-transplant SRNS recurrence risk appears to be low in groups 1 and 3, but high in group 2.
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76
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Yu SMW, Nissaisorakarn P, Husain I, Jim B. Proteinuric Kidney Diseases: A Podocyte's Slit Diaphragm and Cytoskeleton Approach. Front Med (Lausanne) 2018; 5:221. [PMID: 30255020 PMCID: PMC6141722 DOI: 10.3389/fmed.2018.00221] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/18/2018] [Indexed: 01/19/2023] Open
Abstract
Proteinuric kidney diseases are a group of disorders with diverse pathological mechanisms associated with significant losses of protein in the urine. The glomerular filtration barrier (GFB), comprised of the three important layers, the fenestrated glomerular endothelium, the glomerular basement membrane (GBM), and the podocyte, dictates that disruption of any one of these structures should lead to proteinuric disease. Podocytes, in particular, have long been considered as the final gatekeeper of the GFB. This specialized visceral epithelial cell contains a complex framework of cytoskeletons forming foot processes and mediate important cell signaling to maintain podocyte health. In this review, we will focus on slit diaphragm proteins such as nephrin, podocin, TRPC6/5, as well as cytoskeletal proteins Rho/small GTPases and synaptopodin and their respective roles in participating in the pathogenesis of proteinuric kidney diseases. Furthermore, we will summarize the potential therapeutic options targeting the podocyte to treat this group of kidney diseases.
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Affiliation(s)
- Samuel Mon-Wei Yu
- Department of Medicine, Jacobi Medical Center, Bronx, NY, United States
| | | | - Irma Husain
- Department of Medicine, James J. Peters VA Medical Center, Bronx, NY, United States
| | - Belinda Jim
- Department of Medicine, Jacobi Medical Center, Bronx, NY, United States.,Renal Division, Jacobi Medical Center, Bronx, NY, United States
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77
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Elmonem MA, Berlingerio SP, van den Heuvel LP, de Witte PA, Lowe M, Levtchenko EN. Genetic Renal Diseases: The Emerging Role of Zebrafish Models. Cells 2018; 7:cells7090130. [PMID: 30200518 PMCID: PMC6162634 DOI: 10.3390/cells7090130] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 08/27/2018] [Accepted: 08/29/2018] [Indexed: 12/14/2022] Open
Abstract
The structural and functional similarity of the larval zebrafish pronephros to the human nephron, together with the recent development of easier and more precise techniques to manipulate the zebrafish genome have motivated many researchers to model human renal diseases in the zebrafish. Over the last few years, great advances have been made, not only in the modeling techniques of genetic diseases in the zebrafish, but also in how to validate and exploit these models, crossing the bridge towards more informative explanations of disease pathophysiology and better designed therapeutic interventions in a cost-effective in vivo system. Here, we review the significant progress in these areas giving special attention to the renal phenotype evaluation techniques. We further discuss the future applications of such models, particularly their role in revealing new genetic diseases of the kidney and their potential use in personalized medicine.
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Affiliation(s)
- Mohamed A Elmonem
- Department of Pediatric Nephrology & Development and Regeneration, University Hospitals Leuven, KU Leuven-University of Leuven, Herestraat 49, Box 817, 3000 Leuven, Belgium.
- Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, 11628 Cairo, Egypt.
| | - Sante Princiero Berlingerio
- Department of Pediatric Nephrology & Development and Regeneration, University Hospitals Leuven, KU Leuven-University of Leuven, Herestraat 49, Box 817, 3000 Leuven, Belgium.
| | - Lambertus P van den Heuvel
- Department of Pediatric Nephrology & Development and Regeneration, University Hospitals Leuven, KU Leuven-University of Leuven, Herestraat 49, Box 817, 3000 Leuven, Belgium.
- Department of Pediatric Nephrology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands.
| | - Peter A de Witte
- Laboratory for Molecular Bio-Discovery, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven-University of Leuven, 3000 Leuven, Belgium.
| | - Martin Lowe
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK.
| | - Elena N Levtchenko
- Department of Pediatric Nephrology & Development and Regeneration, University Hospitals Leuven, KU Leuven-University of Leuven, Herestraat 49, Box 817, 3000 Leuven, Belgium.
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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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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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80
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Bertelli R, Bonanni A, Caridi G, Canepa A, Ghiggeri GM. Molecular and Cellular Mechanisms for Proteinuria in Minimal Change Disease. Front Med (Lausanne) 2018; 5:170. [PMID: 29942802 PMCID: PMC6004767 DOI: 10.3389/fmed.2018.00170] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 05/15/2018] [Indexed: 12/15/2022] Open
Abstract
Minimal Change Disease (MCD) is a clinical condition characterized by acute nephrotic syndrome, no evident renal lesions at histology and good response to steroids. However, frequent recurrence of the disease requires additional therapies associated with steroids. Such multi-drug dependence and frequent relapses may cause disease evolution to focal and segmental glomerulosclerosis (FSGS) over time. The differences between the two conditions are not well defined, since molecular mechanisms may be shared by the two diseases. In some cases, genetic analysis can make it possible to distinguish MCD from FSGS; however, there are cases of overlap. Several hypotheses on mechanisms underlying MCD and potential molecular triggers have been proposed. Most studies were conducted on animal models of proteinuria that partially mimic MCD and may be useful to study glomerulosclerosis evolution; however, they do not demonstrate a clear-cut separation between MCD and FSGS. Puromycin Aminonucleoside and Adriamycin nephrosis are models of glomerular oxidative damage, characterized by loss of glomerular basement membrane polyanions resembling MCD at the onset and, at more advanced stages, by glomerulosclerosis resembling FSGS. Also Buffalo/Mna rats present initial lesions of MCD, subsequently evolving to FSGS; this mechanism of renal damage is clearer since this rat strain inherits the unique characteristic of overexpressing Th2 cytokines. In Lipopolysaccharide nephropathy, an immunological condition of renal toxicity linked to B7-1(CD80), mice develop transient proteinuria that lasts a few days. Overall, animal models are useful and necessary considering that they reproduce the evolution from MCD to FSGS that is, in part, due to persistence of proteinuria. The role of T/Treg/Bcells on human MCD has been discussed. Many cytokines, immunomodulatory mechanisms, and several molecules have been defined as a specific cause of proteinuria. However, the hypothesis of a single cell subset or molecule as cause of MCD is not supported by research and an interactive process seems more logical. The implication or interactive role of oxidants, Th2 cytokines, Th17, Tregs, B7-1(CD80), CD40/CD40L, c-Mip, TNF, uPA/suPAR, Angiopoietin-like 4 still awaits a definitive confirmation. Whole genome sequencing studies could help to define specific genetic features that justify a definition of MCD as a “clinical-pathology-genetic entity.”
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Affiliation(s)
| | | | | | - Alberto Canepa
- Nephrology, Dialysis, Transplantation Unit, Integrated Department of Pediatrics and Hemato-Oncology Sciences, Istituto Giannina Gaslini IRCCS, Genoa, Italy
| | - G M Ghiggeri
- Laboratory of Molecular Nephrology, Genoa, Italy.,Nephrology, Dialysis, Transplantation Unit, Integrated Department of Pediatrics and Hemato-Oncology Sciences, Istituto Giannina Gaslini IRCCS, Genoa, Italy
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81
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Zhao X, Hwang DY, Kao HY. The Role of Glucocorticoid Receptors in Podocytes and Nephrotic Syndrome. NUCLEAR RECEPTOR RESEARCH 2018; 5. [PMID: 30417008 PMCID: PMC6224173 DOI: 10.11131/2018/101323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Glucocorticoid receptor (GC), a founding member of the nuclear hormone receptor superfamily, is a glucocorticoid-activated transcription factor that regulates gene expression and controls the development and homeostasis of human podocytes. Synthetic glucocorticoids are the standard treatment regimens for proteinuria (protein in the urine) and nephrotic syndrome (NS) caused by kidney diseases. These include minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN) and immunoglobulin A nephropathy (IgAN) or subsequent complications due to diabetes mellitus or HIV infection. However, unwanted side effects and steroid-resistance remain major issues for their long-term use. Furthermore, the mechanism by which glucocorticoids elicit their renoprotective activity in podocyte and glomeruli is poorly understood. Podocytes are highly differentiated epithelial cells that contribute to the integrity of kidney glomerular filtration barrier. Injury or loss of podocytes leads to proteinuria and nephrotic syndrome. Recent studies in multiple experimental models have begun to explore the mechanism of GC action in podocytes. This review will discuss progress in our understanding of the role of glucocorticoid receptor and glucocorticoids in podocyte physiology and their renoprotective activity in nephrotic syndrome.
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Affiliation(s)
- Xuan Zhao
- Department of Biochemistry, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA
| | - Daw-Yang Hwang
- Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hung-Ying Kao
- Department of Biochemistry, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA
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82
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Cil O, Perwad F. Monogenic Causes of Proteinuria in Children. Front Med (Lausanne) 2018; 5:55. [PMID: 29594119 PMCID: PMC5858124 DOI: 10.3389/fmed.2018.00055] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 02/15/2018] [Indexed: 01/02/2023] Open
Abstract
Glomerular disease is a common cause for proteinuria and chronic kidney disease leading to end-stage renal disease requiring dialysis or kidney transplantation in children. Nephrotic syndrome in children is diagnosed by the presence of a triad of proteinuria, hypoalbuminemia, and edema. Minimal change disease is the most common histopathological finding in children and adolescents with nephrotic syndrome. Focal segmental sclerosis is also found in children and is the most common pathological finding in patients with monogenic causes of nephrotic syndrome. Current classification system for nephrotic syndrome is based on response to steroid therapy as a majority of patients develop steroid sensitive nephrotic syndrome regardless of histopathological diagnosis or the presence of genetic mutations. Recent studies investigating the genetics of nephrotic syndrome have shed light on the pathophysiology and mechanisms of proteinuria in nephrotic syndrome. Gene mutations have been identified in several subcellular compartments of the glomerular podocyte and play a critical role in mitochondrial function, actin cytoskeleton dynamics, cell-matrix interactions, slit diaphragm, and podocyte integrity. A subset of genetic mutations are known to cause nephrotic syndrome that is responsive to immunosuppressive therapy but clinical data are limited with respect to renal prognosis and disease progression in a majority of patients. To date, more than 50 genes have been identified as causative factors in nephrotic syndrome in children and adults. As genetic testing becomes more prevalent and affordable, we expect rapid advances in our understanding of mechanisms of proteinuria and genetic diagnosis will help direct future therapy for individual patients.
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Affiliation(s)
- Onur Cil
- Department of Pediatrics, Division of Nephrology, University of California San Francisco, San Francisco, CA, United States
| | - Farzana Perwad
- Department of Pediatrics, Division of Nephrology, University of California San Francisco, San Francisco, CA, United States
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83
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Fennelly N, Kennedy C, Jenkinson A, Connaughton D, Stapleton C, Dorman A, Doyle B, Conlon P. Clinical Heterogeneity in Familial IgA Nephropathy. Nephron Clin Pract 2018; 139:63-69. [DOI: 10.1159/000486018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/22/2017] [Indexed: 11/19/2022] Open
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Abstract
Idiopathic steroid-resistant nephrotic syndrome (SRNS) is most frequently characterized by focal segmental glomerulosclerosis (FSGS) but also other histological lesions, such as diffuse mesangial sclerosis. In the past two decades, a multitude of genetic causes of SRNS have been discovered raising the question of effective treatment in this cohort. Although no controlled studies are available, this review will discuss treatment options including pharmacologic interventions aiming at the attenuation of proteinuria in genetic causes of SRNS, such as inhibitors of the renin-angiotensin-aldosterone system and indomethacin. Also, the potential impact of other interventions to improve podocyte stability will be addressed. In this respect, the treatment with cyclosporine A (CsA) is of interest, since a podocyte stabilizing effect has been demonstrated in various experimental models. Although clinical response to CsA in children with genetic forms of SRNS is inferior to sporadic SRNS, some recent studies show that partial and even complete response can be achieved even in individual patients inherited forms of nephrotic syndrome. Ideally, improved pharmacologic and molecular approaches to induce partial or even complete remission will be available in the future, thus slowing or even preventing the progression toward end-stage renal disease.
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Affiliation(s)
- Markus J Kemper
- AK Nord Heidberg, Asklepios Medical School GmbH, Hamburg, Germany
| | - Anja Lemke
- Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
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85
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Gehrig J, Pandey G, Westhoff JH. Zebrafish as a Model for Drug Screening in Genetic Kidney Diseases. Front Pediatr 2018; 6:183. [PMID: 30003073 PMCID: PMC6031734 DOI: 10.3389/fped.2018.00183] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 06/04/2018] [Indexed: 12/17/2022] Open
Abstract
Genetic disorders account for a wide range of renal diseases emerging during childhood and adolescence. Due to the utilization of modern biochemical and biomedical techniques, the number of identified disease-associated genes is increasing rapidly. Modeling of congenital human disease in animals is key to our understanding of the biological mechanism underlying pathological processes and thus developing novel potential treatment options. The zebrafish (Danio rerio) has been established as a versatile small vertebrate organism that is widely used for studying human inherited diseases. Genetic accessibility in combination with elegant experimental methods in zebrafish permit modeling of human genetic diseases and dissecting the perturbation of underlying cellular networks and physiological processes. Beyond its utility for genetic analysis and pathophysiological and mechanistic studies, zebrafish embryos, and larvae are amenable for phenotypic screening approaches employing high-content and high-throughput experiments using automated microscopy. This includes large-scale chemical screening experiments using genetic models for searching for disease-modulating compounds. Phenotype-based approaches of drug discovery have been successfully performed in diverse zebrafish-based screening applications with various phenotypic readouts. As a result, these can lead to the identification of candidate substances that are further examined in preclinical and clinical trials. In this review, we discuss zebrafish models for inherited kidney disease as well as requirements and considerations for the technical realization of drug screening experiments in zebrafish.
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Affiliation(s)
- Jochen Gehrig
- Acquifer is a Division of Ditabis, Digital Biomedical Imaging Systems AG, Pforzheim, Germany
| | - Gunjan Pandey
- Acquifer is a Division of Ditabis, Digital Biomedical Imaging Systems AG, Pforzheim, Germany.,Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
| | - Jens H Westhoff
- Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
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86
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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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87
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Molnar AO, Barua M, Konvalinka A, Schick-Makaroff K. Patient Engagement in Kidney Research: Opportunities and Challenges Ahead. Can J Kidney Health Dis 2017; 4:2054358117740583. [PMID: 29225906 PMCID: PMC5714072 DOI: 10.1177/2054358117740583] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/22/2017] [Indexed: 12/31/2022] Open
Abstract
PURPOSE OF REVIEW Patient engagement in research is increasingly recognized as an important component of the research process and may facilitate translation of research findings. To heighten awareness on this important topic, this review presents opportunities and challenges of patient engagement in research, drawing on specific examples from 4 areas of Canadian kidney research conducted by New Investigators in the Kidney Research Scientist Core Education and National Training (KRESCENT) Program. SOURCES OF INFORMATION Research expertise, published reports, peer-reviewed articles, and research funding body websites. METHODS In this review, the definition, purpose, and potential benefits of patient engagement in research are discussed. Approaches toward patient engagement that may help with translation and uptake of research findings into clinical practice are highlighted. Opportunities and challenges of patient engagement are presented in both basic science and clinical research with the following examples of kidney research: (1) precision care in focal and segmental glomerulosclerosis, (2) systems biology approaches to improve management of chronic kidney disease and enhance kidney graft survival, (3) reducing the incidence of suboptimal dialysis initiation, and (4) use of patient-reported outcome measures (PROMs) and patient-reported experience measures (PREMs) in kidney practice. KEY FINDINGS Clinical research affords more obvious opportunities for patient engagement. The most obvious step at which to engage patients is in the setting of research priorities. Engagement at all stages of the research cycle may prove to be more challenging, and requires a detailed plan, along with funds and infrastructure to ensure that it is not merely tokenistic. Basic science research is several steps removed from the clinical application and involves complex scientific concepts, which makes patient engagement inherently more difficult. LIMITATIONS This is a narrative review of the literature that has been partly influenced by the perspectives and experiences of the authors and focuses on research conducted by the authors. The evidence base to support the suggested benefits of patient engagement in research is currently limited. IMPLICATIONS The formal incorporation of patients' priorities, perspectives, and experiences is now recognized as a key component of the research process. If patients and researchers are able to effectively work together, this could enhance research quality and efficiency. To effectively engage patients, proper infrastructure and dedicated funding are needed. Going forward, a rigorous evaluation of patient engagement strategies and their effectiveness will be needed.
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Affiliation(s)
- Amber O. Molnar
- Division of Nephrology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- St Joseph’s Healthcare, Hamilton, Ontario, Canada
| | - Moumita Barua
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada
- Toronto General Hospital Research Institute, Toronto General Hospital, Ontario, Canada
- Department of Medicine, University of Toronto, Ontario, Canada
- Institute of Medical Sciences, University of Toronto, Ontario, Canada
| | - Ana Konvalinka
- Division of Nephrology, University Health Network, Toronto, Ontario, Canada
- Toronto General Hospital Research Institute, Toronto General Hospital, Ontario, Canada
- Department of Medicine, University of Toronto, Ontario, Canada
- Institute of Medical Sciences, University of Toronto, Ontario, Canada
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88
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She J, Yuan Z, Wu Y, Chen J, Kroll J. Targeting erythropoietin protects against proteinuria in type 2 diabetic patients and in zebrafish. Mol Metab 2017; 8:189-202. [PMID: 29203238 PMCID: PMC5985015 DOI: 10.1016/j.molmet.2017.11.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 11/08/2017] [Accepted: 11/09/2017] [Indexed: 12/17/2022] Open
Abstract
Objective Adult human kidneys produce erythropoietin (EPO), which regulates red blood cell formation; however, whether EPO also functions directly on kidney development and controls diabetic kidney disease remains unknown. Here we analyzed the role of EPO in kidney development and under hyperglycemic conditions in zebrafish and in humans. Methods Diabetic patients and respective controls were enrolled in two cohorts. Serum EPO level and urine protein change upon human EPO administration were then analyzed. Transient knockdown and permanent knockout of EPO and EPOR in renal TG(WT1B:EGFP) zebrafish were established using the morpholino technology and CRISPR/Cas9 technology. Zebrafish embryos were phenotypically analyzed using fluorescence microscopy, and functional assays were carried out with the help of TexasRed labeled 70 kDa Dextran. Apoptosis was determined using the TUNEL assay and Annexin V staining, and caspase inhibitor zVADfmk was used for rescue experiments. Results In type 2 diabetic patients, serum EPO level decreased with the duration of diabetes, which was linked to reduced kidney function. Human recombinant EPO supplementation ameliorated proteinuria in diabetic nephropathy patients. In zebrafish, loss-of-function studies for EPO and EPOR, showed morphological and functional alterations within the pronephros, adversely affecting pronephric structure, leading to slit diaphragm dysfunction by increasing apoptosis within the pronephros. Induction of hyperglycemia in zebrafish embryos induced pronephros alterations which were further worsened upon silencing of EPO expression. Conclusions EPO was identified as a direct renal protective factor, promoting renal embryonic development and protecting kidneys from hyperglycemia induced nephropathy. EPO exhibited renal protective and proteinuria ameliorating function in type 2 DM patients and in hyperglycemic zebrafish embryos. Enhanced co-expression of EPO and EPOR was identified in both glomeruli and tubuli of DN patients. EPO and its receptor directly regulate physiological kidney development via repressing apoptosis.
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Affiliation(s)
- Jianqing She
- Department of Cardiology, First Affiliated Hospital of Xi'an Jiaotong University, 710048 Xi'an, People's Republic of China; Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Zuyi Yuan
- Department of Cardiology, First Affiliated Hospital of Xi'an Jiaotong University, 710048 Xi'an, People's Republic of China
| | - Yue Wu
- Department of Cardiology, First Affiliated Hospital of Xi'an Jiaotong University, 710048 Xi'an, People's Republic of China
| | - Junfang Chen
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Jens Kroll
- Department of Vascular Biology and Tumor Angiogenesis, Center for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany.
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Li Y, Wang Y, He Q, Dang X, Cao Y, Wu X, Mo S, He X, Yi Z. Genetic mutational testing of Chinese children with familial hematuria with biopsy‑proven FSGS. Mol Med Rep 2017; 17:1513-1526. [PMID: 29138824 PMCID: PMC5780091 DOI: 10.3892/mmr.2017.8023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 08/31/2017] [Indexed: 12/27/2022] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is a pathological lesion rather than a disease, with a diverse etiology. FSGS may result from genetic and non‑genetic factors. FSGS is considered a podocyte disease due to the fact that in the majority of patients with proven‑FSGS, the lesion results from defects in the podocyte structure or function. However, FSGS does not result exclusively from podocyte‑associated genes, however also from other genes including collagen IV‑associated genes. Patients who carry the collagen type IVA3 chain (COL4A3) or COL4A4 mutations usually exhibit Alport Syndrome (AS), thin basement membrane neuropathy or familial hematuria (FH). Previous studies revealed that long‑time persistent microscopic hematuria may lead to FSGS. A case of a family is presented here where affected individuals exhibited FH with FSGS‑proven, or chronic kidney disease. Renal biopsies were unhelpful and failed to demonstrate glomerular or basement membrane defects consistent with an inherited glomerulopathy, and therefore a possible underlying genetic cause for a unifying diagnosis was pursued. Genomic DNA of the siblings affected by FH with biopsy‑proven FSGS was analyzed, and their father was screened for 18 gene mutations associated with FSGS [nephrin, podocin, CD2 associated protein, phospholipase C ε, actinin α 4, transient receptor potential cation channel subfamily C member 6, inverted formin, FH2 and WH2 domain containing, Wilms tumor 1, LIM homeobox transcription factor 1 β, laminin subunit β 2, laminin subunit β 3, galactosida α, integrin subunit β 4, scavenger receptor class B member 2, coenzyme Q2, decaprenyl diphosphate synthase subunit 2, mitochondrially encoded tRNA leucine 1 (UUA/G; TRNL1) and SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a like 1] using matrix‑assisted laser desorption/ionization time‑of‑flight mass spectrometry technology. Then whole exome sequencing (WES) was performed in the two probands to ascertain whether there were other known or unknown gene mutations that segregated with the disease. Using mass array technology, a TRNL1 missense homozygous mutation (m. 3290T>C) was identified in the probands diagnosed with FH and manifested as FSGS on biopsy. In addition, a COL4A4 missense mutation c. 4195A>T (p. M1399L) in heterozygous pattern was identified using WES. None of these variants were detected in their father. In the present study, a mutation in TRNL1 (m. 3290T>C) was identified, which was the first reported variant associated with FSGS. The COL4A4 (c. 4195A>T) may co‑segregate with FSGS. Screening for COL4A mutations in familial FSGS patients is suggested in the present study. Genetic investigations of families with similar clinical phenotypes should be a priority for nephrologists. The combination of mass array technology and WES may improve the detection rate of genetic mutation with a high level of accuracy.
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Affiliation(s)
- Yongzhen Li
- Division of Pediatric Nephrology, Children's Medical Center of The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Ying Wang
- Division of Pediatric Nephrology, Children's Medical Center of The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Qingnan He
- Division of Pediatric Nephrology, Children's Medical Center of The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Xiqiang Dang
- Division of Pediatric Nephrology, Children's Medical Center of The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Yan Cao
- Division of Pediatric Nephrology, Children's Medical Center of The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Xiaochuan Wu
- Division of Pediatric Nephrology, Children's Medical Center of The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Shuanghong Mo
- Division of Pediatric Nephrology, Children's Medical Center of The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Xiaoxie He
- Division of Pediatric Nephrology, Children's Medical Center of The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
| | - Zhuwen Yi
- Division of Pediatric Nephrology, Children's Medical Center of The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China
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90
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Rao J, Ashraf S, Tan W, van der Ven AT, Gee HY, Braun DA, Fehér K, George SP, Esmaeilniakooshkghazi A, Choi WI, Jobst-Schwan T, Schneider R, Schmidt JM, Widmeier E, Warejko JK, Hermle T, Schapiro D, Lovric S, Shril S, Daga A, Nayir A, Shenoy M, Tse Y, Bald M, Helmchen U, Mir S, Berdeli A, Kari JA, El Desoky S, Soliman NA, Bagga A, Mane S, Jairajpuri MA, Lifton RP, Khurana S, Martins JC, Hildebrandt F. Advillin acts upstream of phospholipase C ϵ1 in steroid-resistant nephrotic syndrome. J Clin Invest 2017; 127:4257-4269. [PMID: 29058690 DOI: 10.1172/jci94138] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 09/19/2017] [Indexed: 11/17/2022] Open
Abstract
Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of chronic kidney disease. Here, we identified recessive mutations in the gene encoding the actin-binding protein advillin (AVIL) in 3 unrelated families with SRNS. While all AVIL mutations resulted in a marked loss of its actin-bundling ability, truncation of AVIL also disrupted colocalization with F-actin, thereby leading to impaired actin binding and severing. Additionally, AVIL colocalized and interacted with the phospholipase enzyme PLCE1 and with the ARP2/3 actin-modulating complex. Knockdown of AVIL in human podocytes reduced actin stress fibers at the cell periphery, prevented recruitment of PLCE1 to the ARP3-rich lamellipodia, blocked EGF-induced generation of diacylglycerol (DAG) by PLCE1, and attenuated the podocyte migration rate (PMR). These effects were reversed by overexpression of WT AVIL but not by overexpression of any of the 3 patient-derived AVIL mutants. The PMR was increased by overexpression of WT Avil or PLCE1, or by EGF stimulation; however, this increased PMR was ameliorated by inhibition of the ARP2/3 complex, indicating that ARP-dependent lamellipodia formation occurs downstream of AVIL and PLCE1 function. Together, these results delineate a comprehensive pathogenic axis of SRNS that integrates loss of AVIL function with alterations in the action of PLCE1, an established SRNS protein.
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Affiliation(s)
- Jia Rao
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Medicine, Nephrology, Children's Hospital of Fudan University, Shanghai, China
| | - Shazia Ashraf
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Biosciences, Jamia Millia Islamia, New Delhi, India
| | - Weizhen Tan
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Amelie T van der Ven
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Heon Yung Gee
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Daniela A Braun
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Krisztina Fehér
- NMR and Structure Analysis Group, Department of Organic and Macromolecular Chemistry, University of Gent, Gent, Belgium
| | - Sudeep P George
- Department of Biology and Biochemistry, University of Houston, Houston,Texas, USA
| | | | - Won-Il Choi
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Tilman Jobst-Schwan
- 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
| | - Johanna Magdalena Schmidt
- 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
| | - Jillian K Warejko
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Tobias Hermle
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - David Schapiro
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Svjetlana Lovric
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Shirlee Shril
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ankana Daga
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ahmet Nayir
- Department of Pediatric Nephrology, Faculty of Medicine, University of Istanbul, Istanbul, Turkey
| | - Mohan Shenoy
- Department of Pediatric Nephrology, Royal Manchester Children's Hospital, Manchester, United Kingdom
| | - Yincent Tse
- Department of Pediatric Nephrology, Great North Children's Hospital, Newcastle Upon Tyne, United Kingdom
| | - Martin Bald
- Olga Children's Hospital, Clinic Stuttgart, Stuttgart, Germany
| | - Udo Helmchen
- Institute of Pathology, Kidney Registry, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Sevgi Mir
- Department of Pediatrics, Molecular Medicine Laboratory, Ege University, Izmir, Turkey
| | - Afig Berdeli
- Department of Pediatrics, Molecular Medicine Laboratory, Ege University, Izmir, Turkey
| | - Jameela A Kari
- Pediatric Nephrology Center of Excellence and Pediatric Department, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Sherif El Desoky
- Pediatric Nephrology Center of Excellence and Pediatric Department, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Neveen A Soliman
- Department of Pediatrics, Center of Pediatric Nephrology and Transplantation, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - Arvind Bagga
- Division of Pediatric Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Shrikant Mane
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Richard P Lifton
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA.,Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| | - Seema Khurana
- Department of Biology and Biochemistry, University of Houston, Houston,Texas, USA.,Baylor College of Medicine, Houston, Texas, USA
| | - Jose C Martins
- NMR and Structure Analysis Group, Department of Organic and Macromolecular Chemistry, University of Gent, Gent, Belgium
| | - Friedhelm Hildebrandt
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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91
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Karp AM, Gbadegesin RA. Genetics of childhood steroid-sensitive nephrotic syndrome. Pediatr Nephrol 2017; 32:1481-1488. [PMID: 27470160 PMCID: PMC5276801 DOI: 10.1007/s00467-016-3456-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 06/27/2016] [Accepted: 06/29/2016] [Indexed: 02/07/2023]
Abstract
The pathogenesis of childhood-onset nephrotic syndrome (NS), disparity in incidence of NS among races, and variable responses to therapies in children with NS have defied explanation to date. In the last 20 years over 50 genetic causes of steroid-resistant nephrotic syndrome (SRNS) have been identified, and at least two disease loci for two pathologic variants of SRNS (focal segmental glomerulosclerosis and membranous nephropathy) have been defined. However, the genetic causes and risk loci for steroid-sensitive nephrotic syndrome (SSNS) remain elusive, partly because SSNS is relatively rare and also because cases of SSNS vary widely in phenotypic expression over time. A recent study of a well-defined modest cohort of children with SSNS identified variants in HLA-DQA1 as a risk factor for SSNS. Here we review what is currently known about the genetics of SSNS and also discuss how recent careful phenotypic and genomic studies reinforce the role of adaptive immunity in the molecular mechanisms of SSNS.
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Affiliation(s)
- Alana M. Karp
- Department of Pediatrics, Division of Nephrology, Emory University, Atlanta, GA, USA
| | - Rasheed A. Gbadegesin
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC,Duke Molecular Physiology Institute, Duke University, Durham, NC,To whom correspondence should be addressed:
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92
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Hypertension Susceptibility Loci are Associated with Anthracycline-related Cardiotoxicity in Long-term Childhood Cancer Survivors. Sci Rep 2017; 7:9698. [PMID: 28851949 PMCID: PMC5575079 DOI: 10.1038/s41598-017-09517-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/21/2017] [Indexed: 01/25/2023] Open
Abstract
Anthracycline-based chemotherapy is associated with dose-dependent, irreversible damage to the heart. Childhood cancer survivors with hypertension after anthracycline exposure are at increased risk of cardiotoxicity, leading to the hypothesis that genetic susceptibility loci for hypertension may serve as predictors for development of late cardiotoxicity. Therefore, we determined the association between 12 GWAS-identified hypertension-susceptibility loci and cardiotoxicity in a cohort of long-term childhood cancer survivors (N = 108) who received anthracyclines and were screened for cardiac function via echocardiograms. Hypertension-susceptibility alleles of PLCE1:rs9327264 and ATP2B1:rs17249754 were significantly associated with cardiotoxicity risk conferring a protective effect with a 64% (95% CI: 0.18–0.76, P = 0.0068) and 74% (95% CI: 0.07–0.96, P = 0.040) reduction in risk, respectively. In RNAseq experiments of human induced pluripotent stem cell (iPSC) derived cardiomyocytes treated with doxorubicin, both PLCE1 and ATP2B1 displayed anthracycline-dependent gene expression profiles. In silico functional assessment further supported this relationship - rs9327264 in PLCE1 (P = 0.0080) and ATP2B1 expression (P = 0.0079) were both significantly associated with daunorubicin IC50 values in a panel of lymphoblastoid cell lines. Our findings demonstrate that the hypertension-susceptibility variants in PLCE1 and ATP2B1 confer a protective effect on risk of developing anthracycline-related cardiotoxicity, and functional analyses suggest that these genes are influenced by exposure to anthracyclines.
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93
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Liu J, Wang W. Genetic basis of adult-onset nephrotic syndrome and focal segmental glomerulosclerosis. Front Med 2017; 11:333-339. [PMID: 28776307 DOI: 10.1007/s11684-017-0564-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/02/2017] [Indexed: 12/22/2022]
Abstract
Nephrotic syndrome (NS) is one of the most common glomerular diseases with signs of nephrosis, heavy proteinuria, hypoalbuminemia, and edema. Dysfunction of glomerular filtration barrier causes protein loss through the kidneys. Focal segmental glomerulosclerosis (FSGS) accounts for nearly 20% of NS among children and adults. Adult-onset FSGS/NS is often associated with low response to steroid treatment and immunosuppressive medication and poor renal survival. Several genes involved in NS and FSGS have been identified by linkage analysis and next-generation sequencing. Most of these genes encode proteins and are highly expressed in glomerular podocytes, which play crucial roles in slit-diaphragm signaling, regulation of actin cytoskeleton dynamics and maintenance of podocyte integrity, and cell-matrix interactions. In this review, we focus on the recently identified genes in the adult-onset NS and FSGS and discuss clinical significance of screening of these genes.
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Affiliation(s)
- Jian Liu
- Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.,Department of Nephrology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Weiming Wang
- Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China. .,Department of Nephrology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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94
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Improved diagnostic yield compared with targeted gene sequencing panels suggests a role for whole-genome sequencing as a first-tier genetic test. Genet Med 2017; 20:435-443. [PMID: 28771251 PMCID: PMC5895460 DOI: 10.1038/gim.2017.119] [Citation(s) in RCA: 347] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 06/09/2017] [Indexed: 02/08/2023] Open
Abstract
Purpose Genetic testing is an integral diagnostic component of pediatric medicine. Standard of care is often a time-consuming stepwise approach involving chromosomal microarray analysis and targeted gene sequencing panels, which can be costly and inconclusive. Whole-genome sequencing (WGS) provides a comprehensive testing platform that has the potential to streamline genetic assessments, but there are limited comparative data to guide its clinical use. Methods We prospectively recruited 103 patients from pediatric non-genetic subspecialty clinics, each with a clinical phenotype suggestive of an underlying genetic disorder, and compared the diagnostic yield and coverage of WGS with those of conventional genetic testing. Results WGS identified diagnostic variants in 41% of individuals, representing a significant increase over conventional testing results (24% P = 0.01). Genes clinically sequenced in the cohort (n = 1,226) were well covered by WGS, with a median exonic coverage of 40 × ±8 × (mean ±SD). All the molecular diagnoses made by conventional methods were captured by WGS. The 18 new diagnoses made with WGS included structural and non-exonic sequence variants not detectable with whole-exome sequencing, and confirmed recent disease associations with the genes PIGG, RNU4ATAC, TRIO, and UNC13A. Conclusion WGS as a primary clinical test provided a higher diagnostic yield than conventional genetic testing in a clinically heterogeneous cohort.
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95
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Application of next-generation sequencing technology to diagnosis and treatment of focal segmental glomerulosclerosis. Clin Exp Nephrol 2017; 22:491-500. [PMID: 28752288 PMCID: PMC5956018 DOI: 10.1007/s10157-017-1449-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/06/2017] [Indexed: 12/15/2022]
Abstract
A broad range of genetic and non-genetic factors can lead to kidney injury that manifests as focal segmental glomerulosclerosis (FSGS), which can be classified into primary (idiopathic) and secondary forms. Previous genetic approaches to familial or sporadic cases of FSGS or steroid-resistant nephrotic syndrome identified causal mutations in a subset of genes. Recently, next-generation sequencing (NGS) approaches are becoming a part of a standard assessment in medical genetics. Current knowledge of the comprehensive genomic information is changing the way we think about FSGS and draws attention not only to identification of novel causal genes, but also to potential roles for combinations of mutations in multiple genes, mutations with complex inheritance, and susceptibility genes with variable penetrance carrying relatively minor but significant effects. This review provides an update on recent advances in the genetic analysis of FSGS and highlights the potential as well as the new challenges of NGS for diagnosis and mechanism-based treatment of FSGS.
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96
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Lu J, Lou H, Fu R, Lu D, Zhang F, Wu Z, Zhang X, Li C, Fang B, Pu F, Wei J, Wei Q, Zhang C, Wang X, Lu Y, Yan S, Yang Y, Jin L, Xu S. Assessing genome-wide copy number variation in the Han Chinese population. J Med Genet 2017; 54:685-692. [PMID: 28705883 DOI: 10.1136/jmedgenet-2017-104613] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 06/08/2017] [Accepted: 06/08/2017] [Indexed: 12/22/2022]
Abstract
BACKGROUND Copy number variation (CNV) is a valuable source of genetic diversity in the human genome and a well-recognised cause of various genetic diseases. However, CNVs have been considerably under-represented in population-based studies, particularly the Han Chinese which is the largest ethnic group in the world. OBJECTIVES To build a representative CNV map for the Han Chinese population. METHODS We conducted a genome-wide CNV study involving 451 male Han Chinese samples from 11 geographical regions encompassing 28 dialect groups, representing a less-biased panel compared with the currently available data. We detected CNVs by using 4.2M NimbleGen comparative genomic hybridisation array and whole-genome deep sequencing of 51 samples to optimise the filtering conditions in CNV discovery. RESULTS A comprehensive Han Chinese CNV map was built based on a set of high-quality variants (positive predictive value >0.8, with sizes ranging from 369 bp to 4.16 Mb and a median of 5907 bp). The map consists of 4012 CNV regions (CNVRs), and more than half are novel to the 30 East Asian CNV Project and the 1000 Genomes Project Phase 3. We further identified 81 CNVRs specific to regional groups, which was indicative of the subpopulation structure within the Han Chinese population. CONCLUSIONS Our data are complementary to public data sources, and the CNV map may facilitate in the identification of pathogenic CNVs and further biomedical research studies involving the Han Chinese population.
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Affiliation(s)
- Jianqi Lu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Haiyi Lou
- Max Planck Independent Research Group on Population Genomics, CAS-MPG Partner Institute for Computational Biology, Shanghai, China
| | - Ruiqing Fu
- Max Planck Independent Research Group on Population Genomics, CAS-MPG Partner Institute for Computational Biology, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Dongsheng Lu
- Max Planck Independent Research Group on Population Genomics, CAS-MPG Partner Institute for Computational Biology, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Feng Zhang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China.,Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, China
| | - Zhendong Wu
- Max Planck Independent Research Group on Population Genomics, CAS-MPG Partner Institute for Computational Biology, Shanghai, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Xi Zhang
- Max Planck Independent Research Group on Population Genomics, CAS-MPG Partner Institute for Computational Biology, Shanghai, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Changhua Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Baijun Fang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Fangfang Pu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Jingning Wei
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Qian Wei
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Chao Zhang
- Max Planck Independent Research Group on Population Genomics, CAS-MPG Partner Institute for Computational Biology, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoji Wang
- Max Planck Independent Research Group on Population Genomics, CAS-MPG Partner Institute for Computational Biology, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yan Lu
- Max Planck Independent Research Group on Population Genomics, CAS-MPG Partner Institute for Computational Biology, Shanghai, China
| | - Shi Yan
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yajun Yang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Li Jin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China.,Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, China
| | - Shuhua Xu
- Max Planck Independent Research Group on Population Genomics, CAS-MPG Partner Institute for Computational Biology, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China.,Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, China
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97
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Whitehorn J, Kien DTH, Quyen NTH, Wills B, Van Vinh Chau N, Tam DTH, Tuan NM, Jaenisch T, Hibberd M, Khor CC, Simmons CP. Genetic variants of MICB and PLCE1 and associations with the laboratory features of dengue. BMC Infect Dis 2017; 17:412. [PMID: 28599625 PMCID: PMC5466782 DOI: 10.1186/s12879-017-2514-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 06/01/2017] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND A previous genome-wide association study identified 2 susceptibility loci for severe dengue at MICB rs3132468 and PLCE1 rs3740360 and further work showed these mutations to be also associated with less severe clinical presentations. The aim of this study was to determine if these specific loci were associated with laboratory features of dengue that correlate with clinical severity with the aim of elucidating the functional basis of these genetic variants. METHODS This was a case-only analysis of laboratory-confirmed dengue patients obtained from 2 prospective cohort studies and 1 randomised clinical trial in Vietnam (Trial registration: ISRCTN ISRCTN03147572. Registered 24th July 2012). 2742 dengue cases were successfully genotyped at MICB rs3132468 and PLCE1 rs3740360. Laboratory variables were compared between genotypes and stratified by DENV serotype. RESULTS The analysis showed no association between MICB and PLCE1 genotype and early viraemia level, platelet nadir, white cell count nadir, or maximum haematocrit in both overall analysis and in analysis stratified by serotype. DISCUSSION The lack of an association between genotype and viremia level may reflect the sampling procedures within the included studies. The study findings mean that the functional basis of these mutations remains unclear. TRIAL REGISTRATION ISRCTN ISRCTN03147572 . Registered 24th July 2012.
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Affiliation(s)
- James Whitehorn
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK. .,Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam.
| | - Duong Thi Hue Kien
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam
| | - Nguyen Than Ha Quyen
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam
| | - Bridget Wills
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam.,Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nguyen Van Vinh Chau
- Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam
| | - Dong Thi Hoai Tam
- Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Viet Nam
| | | | - Thomas Jaenisch
- Department of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Martin Hibberd
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK.,Genome Institute of Singapore, Biopolis Way, Singapore, Singapore
| | - Chiea Chuen Khor
- School of Public Health, National University of Singapore, Singapore, Singapore.,Department of Paediatrics, National University of Singapore, Singapore, Singapore.,Department of Ophthalmology, National University of Singapore, Singapore, Singapore
| | - Cameron P Simmons
- Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute, Melbourne, VIC, 3010, Australia
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98
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Dogra S, Kaskel F. Steroid-resistant nephrotic syndrome: a persistent challenge for pediatric nephrology. Pediatr Nephrol 2017; 32:965-974. [PMID: 27783158 DOI: 10.1007/s00467-016-3459-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 06/23/2016] [Accepted: 06/24/2016] [Indexed: 12/19/2022]
Abstract
Steroid-resistant nephrotic syndrome remains a challenge to treat, but various efforts are underway to better understand the pathogenesis and improve patient outcomes. This review provides an update on the newer advances in understanding the molecular etiologies for a variety of podocyte abnormalities, potential circulating factors that may initiate and sustain the steroid-resistant state, genetic mutations, and precision medicine treatment modalities in this continuously perplexing disorder.
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Affiliation(s)
- Samriti Dogra
- Division of Pediatric Nephrology, Department of Pediatrics, Connecticut Children's Medical Center, 282 Washington Street, Hartford, CT, 06095, USA.
| | - Frederick Kaskel
- Division of Pediatric Nephrology, Department of Pediatrics, Children's Hospital at Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA
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Zhao XK, Mao YM, Meng H, Song X, Hu SJ, Lv S, Cheng R, Zhang TJ, Han XN, Ren JL, Qi YJ, Wang LD. Shared susceptibility loci at 2q33 region for lung and esophageal cancers in high-incidence areas of esophageal cancer in northern China. PLoS One 2017; 12:e0177504. [PMID: 28542283 PMCID: PMC5436667 DOI: 10.1371/journal.pone.0177504] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 04/30/2017] [Indexed: 11/19/2022] Open
Abstract
Background Cancers from lung and esophagus are the leading causes of cancer-related deaths in China and share many similarities in terms of histological type, risk factors and genetic variants. Recent genome-wide association studies (GWAS) in Chinese esophageal cancer patients have demonstrated six high-risk candidate single nucleotide polymorphisms (SNPs). Thus, the present study aimed to determine the risk of these SNPs predisposing to lung cancer in Chinese population. Methods A total of 1170 lung cancer patients and 1530 normal subjects were enrolled in this study from high-incidence areas for esophageal cancer in Henan, northern China. Five milliliters of blood were collected from all subjects for genotyping. Genotyping of 20 high-risk SNP loci identified from genome-wide association studies (GWAS) on esophageal, lung and gastric cancers was performed using TaqMan allelic discrimination assays. Polymorphisms were examined for deviation from Hardy-Weinberg equilibrium (HWE) using Х2 test. Bonferroni correction was performed to correct the statistical significance of 20 SNPs with the risk of lung cancer. The Pearson’s Х2 test was used to compare the distributions of gender, TNM stage, histopathological type, smoking and family history by lung susceptibility genotypes. Kaplan-Meier and Cox regression analyses were carried out to evaluate the associations between genetic variants and overall survival. Results Four of the 20 SNPs identified as high-risk SNPs in Chinese esophageal cancer showed increased risk for Chinese lung cancer, which included rs3769823 (OR = 1.26; 95% CI = 1.107–1.509; P = 0.02), rs10931936 (OR = 1.283; 95% CI = 1.100–1.495; P = 0.04), rs2244438 (OR = 1.294; 95% CI = 1.098–1.525; P = 0.04) and rs13016963 (OR = 1.268; 95% CI = 1.089–1.447; P = 0.04). All these SNPs were located at 2q33 region harboringgenes of CASP8, ALS2CR12 and TRAK2. However, none of these susceptibility SNPs was observed to be significantly associated with gender, TNM stage, histopathological type, smoking, family history and overall survival. Conclusions The present study identified four high-risk SNPs at 2q33 locus for Chinese lung cancer and demonstrated the shared susceptibility loci at 2q33 region for Chinese lung and esophageal cancers.
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Affiliation(s)
- Xue Ke Zhao
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yi Min Mao
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Hui Meng
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Xin Song
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Shou Jia Hu
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Shuang Lv
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Rang Cheng
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Tang Juan Zhang
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Xue Na Han
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Jing Li Ren
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yi Jun Qi
- Henan Key Laboratory of Cancer Epigenetic, Cancer Institute, The First Affiliated Hospital, College of Clinical Medicine, Henan University of Science and Technology, Luoyang, Henan, China
| | - Li Dong Wang
- Henan Key Laboratory for Esophageal Cancer Research, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- * E-mail:
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Choi YW, Kim YG, Song MY, Moon JY, Jeong KH, Lee TW, Ihm CG, Park KS, Lee SH. Potential urine proteomics biomarkers for primary nephrotic syndrome. Clin Proteomics 2017; 14:18. [PMID: 28522940 PMCID: PMC5434615 DOI: 10.1186/s12014-017-9153-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 05/06/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Nephrotic syndrome (NS) is a nonspecific kidney disorder, commonly caused by minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), and membranous nephropathy (MN). Here we analyzed urinary protein profiles, aiming to discover disease-specific biomarkers of these three common diseases in NS. METHODS Sixteen urine samples were collected from patients with biopsy-proven NS and healthy controls. After removal of high-abundance proteins, the urinary protein profile was analyzed by LC-MS/MS to generate a discovery set. For validation, ELISA was used to analyze the selected proteins in 61 urine samples. RESULTS The discovery set included 228 urine proteins, of which 22 proteins were differently expressed in MCD, MN, and FSGS. Among these, C9, CD14, and SERPINA1 were validated by ELISA. All three proteins were elevated in MCD, MN, and FSGS groups compared with in IgA nephropathy and healthy controls. When a regression model was applied, receiver operating characteristic analysis clearly discriminated MCD from the other causative diseases in NS. CONCLUSIONS We developed a disease-specific protein panel that discriminated between three main causes of NS. Through this pilot study, we suggest that urine proteomics could be a non-invasive and clinically available tool to discriminate MCD from MN and FSGS.
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Affiliation(s)
- Young Wook Choi
- Division of Nephrology, Department of Internal Medicine, Kyung Hee University School of Medicine, 892 Dongnam-ro, Gangdong-gu, Seoul, Korea
| | - Yang Gyun Kim
- Division of Nephrology, Department of Internal Medicine, Kyung Hee University School of Medicine, 892 Dongnam-ro, Gangdong-gu, Seoul, Korea
| | - Min-Young Song
- Department of Physiology, Kyung Hee University School of Medicine, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, Korea
| | - Ju-Young Moon
- Division of Nephrology, Department of Internal Medicine, Kyung Hee University School of Medicine, 892 Dongnam-ro, Gangdong-gu, Seoul, Korea
| | - Kyung-Hwan Jeong
- Division of Nephrology, Department of Internal Medicine, Kyung Hee University School of Medicine, 892 Dongnam-ro, Gangdong-gu, Seoul, Korea
| | - Tae-Won Lee
- Division of Nephrology, Department of Internal Medicine, Kyung Hee University School of Medicine, 892 Dongnam-ro, Gangdong-gu, Seoul, Korea
| | - Chun-Gyoo Ihm
- Division of Nephrology, Department of Internal Medicine, Kyung Hee University School of Medicine, 892 Dongnam-ro, Gangdong-gu, Seoul, Korea
| | - Kang-Sik Park
- Department of Physiology, Kyung Hee University School of Medicine, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, Korea
| | - Sang-Ho Lee
- Division of Nephrology, Department of Internal Medicine, Kyung Hee University School of Medicine, 892 Dongnam-ro, Gangdong-gu, Seoul, Korea
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