201
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Armaly Z, Jadaon JE, Jabbour A, Abassi ZA. Preeclampsia: Novel Mechanisms and Potential Therapeutic Approaches. Front Physiol 2018; 9:973. [PMID: 30090069 PMCID: PMC6068263 DOI: 10.3389/fphys.2018.00973] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/02/2018] [Indexed: 01/04/2023] Open
Abstract
Preeclampsia is a serious complication of pregnancy where it affects 5–8% of all pregnancies. It increases the morbidity and mortality of both the fetus and pregnant woman, especially in developing countries. It deleteriously affects several vital organs, including the kidneys, liver, brain, and lung. Although, the pathogenesis of preeclampsia has not yet been fully understood, growing evidence suggests that aberrations in the angiogenic factors levels and coagulopathy are responsible for the clinical manifestations of the disease. The common nominator of tissue damage of all these target organs is endothelial injury, which impedes their normal function. At the renal level, glomerular endothelial injury leads to the development of maternal proteinuria. Actually, peripheral vasoconstriction secondary to maternal systemic inflammation and endothelial cell activation is sufficient for the development of preeclampsia-induced hypertension. Similarly, preeclampsia can cause hepatic and neurologic dysfunction due to vascular damage and/or hypertension. Obviously, preeclampsia adversely affects various organs, however it is not yet clear whether pre-eclampsia per se adversely affects various organs or whether it exposes underlying genetic predispositions to cardiovascular disease that manifest in later life. The current review summarizes recent development in the pathogenesis of preeclampsia with special focus on novel diagnostic biomarkers and their relevance to potential therapeutic options for this disease state. Specifically, the review highlights the renal manifestations of the disease with emphasis on the involvement of angiogenic factors in vascular injury and on how restoration of the angiogenic balance affects renal and cardiovascular outcome of Preeclamptic women.
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Affiliation(s)
- Zaher Armaly
- Department of Nephrology, EMMS Nazareth Hospital, Galilee Faculty of Medicine, Bar-Ilan University, Ramat Gan, Israel
| | - Jimmy E Jadaon
- Department of Obstetrics and Gynecology, EMMS Nazareth Hospital, Galilee Faculty of Medicine, Bar-Ilan University, Ramat Gan, Israel.,Laboratory Medicine, EMMS Nazareth Hospital, Galilee Faculty of Medicine, Bar-Ilan University, Ramat Gan, Israel
| | - Adel Jabbour
- Laboratory Medicine, EMMS Nazareth Hospital, Galilee Faculty of Medicine, Bar-Ilan University, Ramat Gan, Israel
| | - Zaid A Abassi
- Department of Physiology, The Ruth and Burce Rappaport Faculty of Medicine, Technion-IIT, Haifa, Israel.,Department of Laboratory Medicine, Rambam Health Campus, Haifa, Israel
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202
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Machado MCR, Valer FB, Couto-Lima CA, Ramos RGP. Transcriptional cross-regulation of Irre Cell Recognition Module (IRM) members in the Drosophila pupal retina. Mech Dev 2018; 154:193-202. [PMID: 30030087 DOI: 10.1016/j.mod.2018.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 06/26/2018] [Accepted: 07/16/2018] [Indexed: 12/13/2022]
Abstract
Cell adhesion molecules play a central role in morphogenesis, as they mediate the complex range of interactions between different cell types that result in their arrangement in multicellular organs and tissues. How their coordinated dynamic expression in space and time - an essential requirement for their function - is regulated at the genomic and transcriptional levels constitutes an important, albeit still little understood question. The Irre Cell Recognition Module (IRM) is a highly conserved phylogenetically group of structurally related single pass transmembrane glycoproteins belonging to the immunoglobulin superfamily that in Drosophila melanogaster are encoded by the genes roughest (rst), kin-of-irre (kirre), sticks-and-stones (sns) and hibris (hbs). Their cooperative and often partly redundant action are crucial to major developmental processes such axonal pathfinding, myoblast fusion and patterning of the pupal retina. In this latter system rst and kirre display a tightly regulated complementary transcriptional pattern so that lowering rst mRNA levels leads to a concomitant increase in kirre mRNA concentration. Here we investigated whether other IRM components are similarly co-regulated and the extent changes in their mRNA levels affect each other as well as their collective function in retinal patterning. Our results demonstrate that silencing any of the four IRM genes in 24% APF retinae changes the levels all other group members although only kirre and hbs mRNA levels are increased. Furthermore, expression, in a rst null background, of truncated versions of rst cDNA in which the portion encoding the intracellular domain has been partially or completely removed not only can still induce changes in mRNA levels of other IRM members but also result in Kirre mislocalization. Taken together, our data point to the presence of a highly precise and fine-tuned control mechanism coordinating IRM expression that may be crucial to the functional redundancy shown by its components during the patterning of the pupal retina.
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Affiliation(s)
- Maiaro Cabral Rosa Machado
- Department of Cellular and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Felipe Berti Valer
- Department of Cellular and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Carlos Antonio Couto-Lima
- Department of Cellular and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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203
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Hagmann H, Brinkkoetter PT. Experimental Models to Study Podocyte Biology: Stock-Taking the Toolbox of Glomerular Research. Front Pediatr 2018; 6:193. [PMID: 30057894 PMCID: PMC6053518 DOI: 10.3389/fped.2018.00193] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/11/2018] [Indexed: 01/17/2023] Open
Abstract
Diseases affecting the glomeruli of the kidney, the renal filtration units, are a leading cause of chronic kidney disease and end-stage renal failure. Despite recent advances in the understanding of glomerular biology, treatment of these disorders has remained extraordinarily challenging in many cases. The use of experimental models has proven invaluable to study renal, and in particular, glomerular biology and disease. Over the past 15 years, studies identified different and very distinct pathogenic mechanisms that result in damage, loss of glomerular visceral epithelial cells (podocytes) and progressive renal disease. However, animal studies and, in particular, mouse studies are often protracted and cumbersome due to the long reproductive cycle and high keeping costs. Transgenic and heterologous expression models have been speeded-up by novel gene editing techniques, yet they still take months. In addition, given the complex cellular biology of the filtration barrier, certain questions may not be directly addressed using mouse models due to the limited accessibility of podocytes for analysis and imaging. In this review, we will describe alternative models to study podocyte biology experimentally. We specifically discuss current podocyte cell culture models, their role in experimental strategies to analyze pathophysiologic mechanisms as well as limitations with regard to transferability of results. We introduce current models in Caenorhabditis elegans, Drosophila melanogaster, and Danio rerio that allow for analysis of protein interactions, and principle signaling pathways in functional biological structures, and enable high-throughput transgenic expression or compound screens in multicellular organisms.
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Affiliation(s)
| | - Paul T. Brinkkoetter
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
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204
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Verma R, Venkatareddy M, Kalinowski A, Li T, Kukla J, Mollin A, Cara-Fuentes G, Patel SR, Garg P. Nephrin is necessary for podocyte recovery following injury in an adult mature glomerulus. PLoS One 2018; 13:e0198013. [PMID: 29924795 PMCID: PMC6010211 DOI: 10.1371/journal.pone.0198013] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 05/12/2018] [Indexed: 11/28/2022] Open
Abstract
Nephrin (Nphs1) is an adhesion protein that is expressed at the podocyte intercellular junction in the glomerulus. Nphs1 mutations in humans or deletion in animal genetic models results in a developmental failure of foot process formation. A number of studies have shown decrease in expression of nephrin in various proteinuric kidney diseases as well as in animal models of glomerular disease. Decrease in nephrin expression has been suggested to precede podocyte loss and linked to the progression of kidney disease. Whether the decrease in expression of nephrin is related to loss of podocytes or lead to podocyte detachment is unclear. To answer this central question we generated an inducible model of nephrin deletion (Nphs1Tam-Cre) in order to lower nephrin expression in healthy adult mice. Following tamoxifen-induction there was a 75% decrease in nephrin expression by 14 days. The Nphs1Tam-Cre mice had normal foot process ultrastructure and intact filtration barriers up to 4-6 weeks post-induction. Despite the loss of nephrin expression, the podocyte number and density remained unchanged during the initial period. Unexpectedly, nephrin expression, albeit at low levels persisted at the slit diaphragm up to 16-20 weeks post-tamoxifen induction. The mice became progressively proteinuric with glomerular hypertrophy and scarring reminiscent of focal and segmental glomerulosclerosis at 20 weeks. Four week-old Nphs1 knockout mice subjected to protamine sulfate model of podocyte injury demonstrated failure to recover from foot process effacement following heparin sulfate. Similarly, Nphs1 knockout mice failed to recover following nephrotoxic serum (NTS) with persistence of proteinuria and foot process effacement. Our results suggest that as in development, nephrin is necessary for maintenance of a healthy glomerular filter. In contrast to the developmental phenotype, lowering nephrin expression in a mature glomerulus resulted in a slowly progressive disease that histologically resembles FSGS a disease linked closely with podocyte depletion. Podocytes with low levels of nephrin expression are both susceptible and unable to recover following perturbation. Our results suggest that decreased nephrin expression independent of podocyte loss occurring as an early event in proteinuric kidney diseases might play a role in disease progression.
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Affiliation(s)
- Rakesh Verma
- Division of Nephrology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Madhusudan Venkatareddy
- Division of Nephrology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Anne Kalinowski
- Division of Nephrology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Theodore Li
- Division of Nephrology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Joanna Kukla
- Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | | | - Gabriel Cara-Fuentes
- Division of Pediatric Nephrology, Motts Children Hospital, Ann Arbor, Michigan, United States of America
| | - Sanjeevkumar R. Patel
- Division of Nephrology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
- Veterans Administration, VAMC, Ann Arbor, Michigan, United States of America
| | - Puneet Garg
- Division of Nephrology, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
- Veterans Administration, VAMC, Ann Arbor, Michigan, United States of America
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205
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Heimlich JB, Chipoka G, Elsherif L, David E, Ellis G, Kamthunzi P, Krysiak R, Mafunga P, Zhou Q, Cai J, Gopal S, Key NS, Ataga KI. Nephrin as a biomarker of sickle cell glomerulopathy in Malawi. Pediatr Blood Cancer 2018; 65:e26993. [PMID: 29411937 PMCID: PMC5911184 DOI: 10.1002/pbc.26993] [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: 08/15/2017] [Revised: 12/03/2017] [Accepted: 12/22/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Glomerulopathy is an increasingly identified complication in young patients with sickle cell disease (SCD). Hyperfiltration and albuminuria followed by declining glomerular filtration rates and eventual end-stage renal disease (ESRD) is assumed to be the typical progression of glomerular disease. There are only a few reported biomarkers to identify early-stage renal disease in SCD. PROCEDURES We detail the renal profile of 101 children with SCD in Malawi and propose a novel urinary biomarker for the identification of early renal disease. RESULTS Among children with sickle cell anemia, 24.8% had a urine albumin-creatinine ratio of 30 mg/g or above. In univariate analysis, only patients with higher urinary nephrin, a urinary marker of glomerular injury, had significantly greater odds of having albuminuria. In multivariable analysis, nephrin remained significantly associated with albuminuria. A nephrin-creatinine ratio (NCR) cut-point of 622 ng/mg, the 50th percentile, was associated with a 45.8 times greater odds of having albuminuria in children with nephrinuria above this value. Further analysis revealed this urinary NCR cut-point to have 96% sensitivity, 64% specificity, 47% positive predictive value, and 98% negative predictive value for the presence of albuminuria. CONCLUSIONS These data suggest that a substantial number of children with SCD in Malawi have renal disease and could be at risk for worsening nephropathy and ESRD as they age. Our data suggest that urinary nephrin could be utilized as an early marker of glomerular disease in SCD.
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Affiliation(s)
- J. Brett Heimlich
- UNC Project-Malawi, Lilongwe, Malawi,Vanderbilt University Medical Center, Nashville, Tennessee
| | | | - Laila Elsherif
- University of North Carolina, Chapel Hill, North Carolina
| | - Emeraghi David
- University of North Carolina, Chapel Hill, North Carolina
| | - Graham Ellis
- UNC Project-Malawi, Lilongwe, Malawi,Naval Medical Center San Diego, San Diego, CA
| | | | | | | | - Qingning Zhou
- University of North Carolina, Charlotte, North Carolina
| | - Jianwen Cai
- University of North Carolina, Chapel Hill, North Carolina
| | - Satish Gopal
- UNC Project-Malawi, Lilongwe, Malawi,University of North Carolina, Chapel Hill, North Carolina
| | - Nigel S. Key
- University of North Carolina, Chapel Hill, North Carolina
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206
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Modeling Renal Disease "On the Fly". BIOMED RESEARCH INTERNATIONAL 2018; 2018:5697436. [PMID: 29955604 PMCID: PMC6000847 DOI: 10.1155/2018/5697436] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 04/17/2018] [Indexed: 12/22/2022]
Abstract
Detoxification is a fundamental function for all living organisms that need to excrete catabolites and toxins to maintain homeostasis. Kidneys are major organs of detoxification that maintain water and electrolyte balance to preserve physiological functions of vertebrates. In insects, the renal function is carried out by Malpighian tubules and nephrocytes. Due to differences in their circulation, the renal systems of mammalians and insects differ in their functional modalities, yet carry out similar biochemical and physiological functions and share extensive genetic and molecular similarities. Evolutionary conservation can be leveraged to model specific aspects of the complex mammalian kidney function in the genetic powerhouse Drosophila melanogaster to study how genes interact in diseased states. Here, we compare the human and Drosophila renal systems and present selected fly disease models.
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207
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Del Bel LM, Griffiths N, Wilk R, Wei HC, Blagoveshchenskaya A, Burgess J, Polevoy G, Price JV, Mayinger P, Brill JA. The phosphoinositide phosphatase Sac1 regulates cell shape and microtubule stability in the developing Drosophila eye. Development 2018; 145:dev151571. [PMID: 29752385 PMCID: PMC6031321 DOI: 10.1242/dev.151571] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 04/30/2018] [Indexed: 12/15/2022]
Abstract
Epithelial patterning in the developing Drosophila melanogaster eye requires the Neph1 homolog Roughest (Rst), an immunoglobulin family cell surface adhesion molecule expressed in interommatidial cells (IOCs). Here, using a novel temperature-sensitive (ts) allele, we show that the phosphoinositide phosphatase Sac1 is also required for IOC patterning. Sac1ts mutants have rough eyes and retinal patterning defects that resemble rst mutants. Sac1ts retinas exhibit elevated levels of phosphatidylinositol 4-phosphate (PI4P), consistent with the role of Sac1 as a PI4P phosphatase. Indeed, genetic rescue and interaction experiments reveal that restriction of PI4P levels by Sac1 is crucial for normal eye development. Rst is delivered to the cell surface in Sac1ts mutants. However, Sac1ts mutant IOCs exhibit severe defects in microtubule organization, associated with accumulation of Rst and the exocyst subunit Sec8 in enlarged intracellular vesicles upon cold fixation ex vivo Together, our data reveal a novel requirement for Sac1 in promoting microtubule stability and suggest that Rst trafficking occurs in a microtubule- and exocyst-dependent manner.
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Affiliation(s)
- Lauren M Del Bel
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Nigel Griffiths
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Ronit Wilk
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada
| | - Ho-Chun Wei
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, South Sciences Building Room 8166, 8888 University Drive, Burnaby, British Columbia, V5A 1S6, Canada
| | - Anastasia Blagoveshchenskaya
- Division of Nephrology & Hypertension, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd., Portland, Oregon 97239-3098, USA
| | - Jason Burgess
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Gordon Polevoy
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada
| | - James V Price
- Department of Molecular Biology and Biochemistry, Simon Fraser University, South Sciences Building Room 8166, 8888 University Drive, Burnaby, British Columbia, V5A 1S6, Canada
| | - Peter Mayinger
- Division of Nephrology & Hypertension, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd., Portland, Oregon 97239-3098, USA
| | - Julie A Brill
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
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208
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Itoh M, Nakadate K, Matsusaka T, Hunziker W, Sugimoto H. Effects of the differential expression of ZO-1 and ZO-2 on podocyte structure and function. Genes Cells 2018; 23:546-556. [DOI: 10.1111/gtc.12598] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 04/27/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Masahiko Itoh
- Department of Biochemistry; School of Medicine; Dokkyo Medical University; Mibu-machi Japan
| | - Kazuhiko Nakadate
- Department of Basic Biology, Educational and Research Center for Pharmacy; Meiji Pharmaceutical University; Tokyo Japan
| | - Taiji Matsusaka
- Department of Molecular Life Sciences; Tokai University School of Medicine; Isehara Japan
| | - Walter Hunziker
- Epithelial Cell Biology Laboratory; Institute of Molecular and Cell Biology (IMCB); Singapore Singapore
| | - Hiroyuki Sugimoto
- Department of Biochemistry; School of Medicine; Dokkyo Medical University; Mibu-machi Japan
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209
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Wang P, Zhao F, Nie X, Liu J, Yu Z. Knockdown of NUP160 inhibits cell proliferation, induces apoptosis, autophagy and cell migration, and alters the expression and localization of podocyte associated molecules in mouse podocytes. Gene 2018; 664:12-21. [PMID: 29704630 DOI: 10.1016/j.gene.2018.04.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 04/19/2018] [Accepted: 04/23/2018] [Indexed: 12/22/2022]
Abstract
Genetic mutations in dozens of monogenic genes can lead to serious podocyte dysfunction, which is a major cause of steroid-resistant nephrotic syndrome (SRNS). The NUP160 gene is expressed in both human kidney and mouse kidney. However, whether knockdown of NUP160 impairs podocytes has not yet been established. Therefore, we knocked down NUP160 by targeted short hairpin RNA (shRNA) in conditionally immortalized mouse podocytes and observed the effect of NUP160 knockdown on the proliferation, apoptosis, autophagy and cell migration of podocytes. We also investigated the effect of NUP160 knockdown on the expression and localization of podocyte associated molecules, such as nephrin, podocin, CD2AP and α-actinin-4. The knockdown of NUP160 significantly inhibited the proliferation of podocytes by decreasing the expression of both cyclin D1 and CDK4, increasing the expression of p27, and inducing S phase arrest. The knockdown of NUP160 promoted the apoptosis and autophagy of podocytes, and enhanced cell migration. The knockdown of NUP160 decreased the expression of nephrin, podocin and CD2AP in podocytes, and increased the expression of α-actinin-4. The knockdown of NUP160 also altered the subcellular localization of nephrin, podocin and CD2AP in podocytes. These results suggest that the knockdown of NUP160 impairs mouse podocytes, i.e. inhibiting cell proliferation, inducing apoptosis, autophagy and cell migration of mouse podocytes, and altering the expression and localization of podocyte associated molecules, including nephrin, podocin, CD2AP and α-actinin-4.
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Affiliation(s)
- Ping Wang
- Department of Pediatrics, Fuzhou Dongfang Hospital, Second Military Medical University, Fuzhou 350025, Fujian, China; The Military Hospital of 92435 Unit of the People's Liberation Army, Ningde 352103, Fujian, China
| | - Feng Zhao
- Department of Pediatrics, Dongfang Hospital, Xiamen University, Fuzhou 350025, Fujian, China
| | - Xiaojing Nie
- Department of Pediatrics, Dongfang Hospital, Xiamen University, Fuzhou 350025, Fujian, China
| | - Jiewei Liu
- Department of Pediatrics, Fuzhou Dongfang Hospital, Second Military Medical University, Fuzhou 350025, Fujian, China
| | - Zihua Yu
- Department of Pediatrics, Fuzhou Dongfang Hospital, Second Military Medical University, Fuzhou 350025, Fujian, China; Department of Pediatrics, Dongfang Hospital, Xiamen University, Fuzhou 350025, Fujian, China; Department of Pediatrics, Fuzhou Clinical Medical College, Fujian Medical University, Fuzhou 350025, Fujian, China.
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210
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Schroeter CB, Koehler S, Kann M, Schermer B, Benzing T, Brinkkoetter PT, Rinschen MM. Protein half-life determines expression of proteostatic networks in podocyte differentiation. FASEB J 2018; 32:4696-4713. [PMID: 29694247 DOI: 10.1096/fj.201701307r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Podocytes are highly specialized, epithelial, postmitotic cells, which maintain the renal filtration barrier. When adapting to considerable metabolic and mechanical stress, podocytes need to accurately maintain their proteome. Immortalized podocyte cell lines are a widely used model for studying podocyte biology in health and disease in vitro. In this study, we performed a comprehensive proteomic analysis of the cultured human podocyte proteome in both proliferative and differentiated conditions at a depth of >7000 proteins. Similar to mouse podocytes, human podocyte differentiation involved a shift in proteostasis: undifferentiated podocytes have high expression of proteasomal proteins, whereas differentiated podocytes have high expression of lysosomal proteins. Additional analyses with pulsed stable-isotope labeling by amino acids in cell culture and protein degradation assays determined protein dynamics and half-lives. These studies unraveled a globally increased stability of proteins in differentiated podocytes. Mitochondrial, cytoskeletal, and membrane proteins were stabilized, particularly in differentiated podocytes. Importantly, protein half-lives strongly contributed to protein abundance in each state. These data suggest that regulation of protein turnover of particular cellular functions determines podocyte differentiation, a paradigm involving mitophagy and, potentially, of importance in conditions of increased podocyte stress and damage.-Schroeter, C. B., Koehler, S., Kann, M., Schermer, B., Benzing, T., Brinkkoetter, P. T., Rinschen, M. M. Protein half-life determines expression of proteostatic networks in podocyte differentiation.
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Affiliation(s)
- Christina B Schroeter
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Sybille Koehler
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Martin Kann
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (SybaCol), Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (SybaCol), Cologne, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Markus M Rinschen
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (SybaCol), Cologne, Germany
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211
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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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212
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The long journey through renal filtration: new pieces in the puzzle of slit diaphragm architecture. Curr Opin Nephrol Hypertens 2018; 26:148-153. [PMID: 28212178 DOI: 10.1097/mnh.0000000000000322] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
PURPOSE OF REVIEW The podocyte slit diaphragm is probably the least understood component of the kidney filtration barrier. In this review, we aim to integrate the most recent findings on the molecular make-up and structural architecture of this specialized cell-cell junction into a current concept of glomerular filtration. RECENT FINDINGS Analysis of cryopreserved mammalian tissue revealed a bipartite composition of the slit diaphragm. Single NEPH1 molecules span the lower part of the slit close to the glomerular basement membrane whereas NEPHRIN molecules are positioned in the apical part toward Bowman's space. This molecular arrangement could lead to heterogeneous ellipsoidal and circular pores, which are mainly located in the central region of the slit diaphragm. SUMMARY Despite having been first identified in the 1970s, the slit diaphragm's structural architecture has not been fully elucidated to date and remains an area of intense research and scientific debate. The slit diaphragm has been initially described as a rigid 'zipper-like' structure in which periodic, rod-like units extend from a podocyte foot processes to a linear central bar, giving rise to homogeneous 4 × 14 nm pores. Several recent findings have challenged these long-held beliefs and instead pointed to an unanticipated complexity of slit diaphragm structure. High-resolution ultrastructural analysis found evidence that the slit diaphragm is a dynamic and adjustable cell-cell junction that forms a nonclogging barrier within the renal filtration system.
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213
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Wen Y, Shah S, Campbell KN. Molecular Mechanisms of Proteinuria in Focal Segmental Glomerulosclerosis. Front Med (Lausanne) 2018; 5:98. [PMID: 29713631 PMCID: PMC5912003 DOI: 10.3389/fmed.2018.00098] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 03/26/2018] [Indexed: 01/01/2023] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is the most common primary glomerular disease resulting in end-stage renal disease in the USA and is increasing in prevalence worldwide. It is a diverse clinical entity with idiopathic, genetic, metabolic, infectious, and other causes that culminate in a characteristic histologic pattern of injury. Proteinuria is a hallmark of FSGS as well as other primary and secondary glomerular disorders. The magnitude of proteinuria at disease onset and during treatment has prognostic implications for renal survival as well as associated cardiovascular morbidity and mortality. Significant advances over the last two decades have shed light on the molecular architecture of the glomerular filtration barrier. The podocyte is the target cell for injury in FSGS. A growing list of disease-causing gene mutations encoding proteins that regulate podocyte survival and homeostasis has been identified in FSGS patients. Several pathogenic and regulatory pathways have been uncovered that result in proteinuria in rodent models and human FSGS. The recurrence of proteinuria and FSGS after kidney transplantation is supporting evidence for the role of a circulating permeability factor in disease pathogenesis. These advances reviewed herein have significant implications for disease classification and therapeutic drug development for FSGS.
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Affiliation(s)
- Yumeng Wen
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Sapna Shah
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Kirk N Campbell
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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214
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Lepori N, Zand L, Sethi S, Fernandez-Juarez G, Fervenza FC. Clinical and pathological phenotype of genetic causes of focal segmental glomerulosclerosis in adults. Clin Kidney J 2018; 11:179-190. [PMID: 29644057 PMCID: PMC5888331 DOI: 10.1093/ckj/sfx143] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 11/17/2017] [Indexed: 02/07/2023] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is a histologic lesion resulting from a variety of pathogenic processes that cause injury to the podocytes. Recently, mutations in more than 50 genes expressed in podocyte or glomerular basement membrane were identified as causing genetic forms of FSGS, the majority of which are characterized by onset in childhood. The prevalence of adult-onset genetic FSGS is likely to be underestimated and its clinical and histological features have not been clearly described. A small number of studies of adult-onset genetic FSGS showed that there is heterogeneity in clinical and histological findings, with a presentation ranging from sub-nephrotic proteinuria to full nephrotic syndrome. A careful evaluation of adult-onset FSGS that do not have typical features of primary or secondary FSGS (familial cases, resistance to immunosuppression and absence of evident cause of secondary FSGS) should include a genetic evaluation. Indeed, recognizing genetic forms of adult-onset FSGS is of the utmost importance, given that this diagnosis will have major implications on treatment strategies, selecting of living-related kidney donor and renal transplantation success.
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Affiliation(s)
- Nicola Lepori
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
- Division of Nephrology and Dialysis, Azienda Ospedaliera G. Brotzu, Cagliari, Italy
| | - Ladan Zand
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Sanjeev Sethi
- Division of Anatomic Pathology, Mayo Clinic, Rochester, MN, USA
| | - Gema Fernandez-Juarez
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
- Nephrology Division, Hospital Universitario Fundacion Alcorcon, Madrid, Spain
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215
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Jin YY, Feng BY, Mao JH. The status quo and challenges of genetic diagnosis in children with steroid-resistant nephrotic syndrome. World J Pediatr 2018; 14:105-109. [PMID: 29644498 DOI: 10.1007/s12519-018-0156-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 03/28/2018] [Indexed: 01/12/2023]
Affiliation(s)
- Yan-Yan Jin
- Department of Nephrology, Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou, 310003, China
| | - Bing-Yu Feng
- Department of Nephrology, Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou, 310003, China.,Department of Paediatrics, The First People's Hospital of Huzhou, Huzhou, 313000, China
| | - Jian-Hua Mao
- Department of Nephrology, Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou, 310003, China.
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216
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Yang JW, Dettmar AK, Kronbichler A, Gee HY, Saleem M, Kim SH, Shin JI. Recent advances of animal model of focal segmental glomerulosclerosis. Clin Exp Nephrol 2018; 22:752-763. [PMID: 29556761 DOI: 10.1007/s10157-018-1552-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 02/26/2018] [Indexed: 12/15/2022]
Abstract
In the last decade, great advances have been made in understanding the genetic basis for focal segmental glomerulosclerosis (FSGS). Animal models using specific gene disruption of the slit diaphragm and cytoskeleton of the foot process mirror the etiology of the human disease. Many animal models have been developed to understand the complex pathophysiology of FSGS. Therefore, we need to know the usefulness and exact methodology of creating animal models. Here, we review classic animal models and newly developed genetic animal models. Classic animal models of FSGS involve direct podocyte injury and indirect podocyte injury due to adaptive responses. However, the phenotype depends on the animal background. Renal ablation and direct podocyte toxin (PAN, adriamycin) models are leading animal models for FSGS, which have some limitations depending on mice background. A second group of animal models were developed using combinations of genetic mutation and toxin, such as NEP25, diphtheria toxin, and Thy1.1 models, which specifically injure podocytes. A third group of animal models involves genetic engineering techniques targeting podocyte expression molecules, such as podocin, CD2-associated protein, and TRPC6 channels. More detailed information about podocytopathy and FSGS can be expected in the coming decade. Different animal models should be used to study FSGS depending on the specific aim and sometimes should be used in combination.
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Affiliation(s)
- Jae Won Yang
- Department of Nephrology, Yonsei University Wonju College of Medicine, Wonju, Gangwon, Republic of Korea
| | - Anne Katrin Dettmar
- Pediatric Nephrology, Department of Pediatrics, Medical University Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas Kronbichler
- Department of Internal Medicine IV (Nephrology and Hypertension), Universitätskliniken Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria
| | - Heon Yung Gee
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Moin Saleem
- Paediatric Renal Medicine, University of Bristol, Bristol, UK.,Children's Renal Unit, Bristol Royal Hospital for Children, Bristol, UK
| | - Seong Heon Kim
- Department of Pediatrics, Pusan National University Children's Hospital, Yangsan, Republic of Korea. .,Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea.
| | - Jae Il Shin
- Department of Pediatrics, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea.
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217
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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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218
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Rider SA, Bruton FA, Collins RG, Conway BR, Mullins JJ. The Efficacy of Puromycin and Adriamycin for Induction of Glomerular Failure in Larval Zebrafish Validated by an Assay of Glomerular Permeability Dynamics. Zebrafish 2018; 15:234-242. [PMID: 29480793 PMCID: PMC5985910 DOI: 10.1089/zeb.2017.1527] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Defects in the glomerular filtration barrier (GFB) play a major role in the onset of human renal diseases. Highly ramified glomerular cells named podocytes are a critical component of the GFB. Injury to podocytes results in abnormal excretion of plasma proteins, which can lead to chronic kidney disease. The conserved paired nephron of larval zebrafish is an excellent model for assessing glomerular function and injury. The efficacy of two known podocyte toxins was tested to refine models of acute podocyte injury in larval zebrafish. The validated compound was then used to test a novel assay of the dynamics of abnormal protein excretion. Injected adriamycin was found to be unsuitable for induction of glomerular injury due to off-target cardiovascular toxicity. In contrast, puromycin treatment resulted in a loss of discriminative filtration, measured by excretion of 70 kDa dextran, and podocyte effacement confirmed by electron microscopy. The dynamics of dextran excretion during puromycin injury modeled the onset of glomerular damage within 24 hours postinjection. These data validate puromycin for induction of acute podocyte injury in zebrafish larvae and describe a semihigh-throughput assay for quantifying the dynamics of abnormal protein excretion.
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Affiliation(s)
- Sebastien Andrew Rider
- 1 Univeristy/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, Little France, The University of Edinburgh , Edinburgh, United Kingdom
| | - Finnius Austin Bruton
- 1 Univeristy/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, Little France, The University of Edinburgh , Edinburgh, United Kingdom
| | | | - Bryan Ronald Conway
- 1 Univeristy/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, Little France, The University of Edinburgh , Edinburgh, United Kingdom
| | - John James Mullins
- 1 Univeristy/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, Little France, The University of Edinburgh , Edinburgh, United Kingdom
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219
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Bérody S, Heidet L, Gribouval O, Harambat J, Niaudet P, Baudouin V, Bacchetta J, Boudaillez B, Dehennault M, de Parscau L, Dunand O, Flodrops H, Fila M, Garnier A, Louillet F, Macher MA, May A, Merieau E, Monceaux F, Pietrement C, Rousset-Rouvière C, Roussey G, Taque S, Tenenbaum J, Ulinski T, Vieux R, Zaloszyc A, Morinière V, Salomon R, Boyer O. Treatment and outcome of congenital nephrotic syndrome. Nephrol Dial Transplant 2018; 34:458-467. [DOI: 10.1093/ndt/gfy015] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 12/24/2017] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sandra Bérody
- Hôpital Necker-Enfants malades, Néphrologie pédiatrique, Assistance Publique des Hôpitaux de Paris, Université Paris Descartes-Sorbonne Paris-Cité, Paris, France
| | - Laurence Heidet
- Hôpital Necker-Enfants malades, Néphrologie pédiatrique, Assistance Publique des Hôpitaux de Paris, Université Paris Descartes-Sorbonne Paris-Cité, Paris, France
- Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Centre de référence du syndrome néphrotique idiopathique de l'enfant et de l'adulte, Hôpital Necker-Enfants Malades, Paris, France
- Inserm U1163, Imagine Institute, Paris, France
| | | | - Jérome Harambat
- Centre Hospitalier Universitaire de Bordeaux, Néphrologie pédiatrique, Bordeaux, France
| | - Patrick Niaudet
- Hôpital Necker-Enfants malades, Néphrologie pédiatrique, Assistance Publique des Hôpitaux de Paris, Université Paris Descartes-Sorbonne Paris-Cité, Paris, France
- Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Centre de référence du syndrome néphrotique idiopathique de l'enfant et de l'adulte, Hôpital Necker-Enfants Malades, Paris, France
- Inserm U1163, Imagine Institute, Paris, France
| | - Veronique Baudouin
- Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Centre de référence du syndrome néphrotique idiopathique de l'enfant et de l'adulte, Hôpital Necker-Enfants Malades, Paris, France
- Hôpital Universitaire Robert Debré, Néphrologie pédiatrique, Paris, France
| | | | | | | | | | - Olivier Dunand
- CHU Felix Guyon, Pédiatrie, Saint-Denis, La Reunion, France
| | | | - Marc Fila
- Centre Hospitalier Regional Universitaire de Montpellier, Néphrologie pédiatrique, Montpellier, France
| | - Arnaud Garnier
- Centre Hospitalier Universitaire de Toulouse, Néphrologie pédiatrique, Toulouse, France
| | | | - Marie-Alice Macher
- Hôpital Universitaire Robert Debré, Néphrologie pédiatrique, Paris, France
| | - Adrien May
- Centre Hospitalier Sud Francilien, Pédiatrie, Corbeil-Essonnes, France
| | | | | | | | | | - Gwenaëlle Roussey
- Centre Hospitalier Universitaire de Nantes, Néphrologie pédiatrique, Nantes, France
| | - Sophie Taque
- Centre Hospitalier Universitaire de Rennes, Pédiatrie, Rennes, France
| | - Julie Tenenbaum
- Centre Hospitalier Regional Universitaire de Montpellier, Néphrologie pédiatrique, Montpellier, France
| | - Tim Ulinski
- Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Centre de référence du syndrome néphrotique idiopathique de l'enfant et de l'adulte, Hôpital Necker-Enfants Malades, Paris, France
- Hôpital Armand-Trousseau, Néphrologie pédiatrique, Paris, France
| | - Rachel Vieux
- Centre Hospitalier Universitaire de Nancy, Pédiatrie, Nancy, France
| | | | | | - Rémi Salomon
- Hôpital Necker-Enfants malades, Néphrologie pédiatrique, Assistance Publique des Hôpitaux de Paris, Université Paris Descartes-Sorbonne Paris-Cité, Paris, France
- Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Centre de référence du syndrome néphrotique idiopathique de l'enfant et de l'adulte, Hôpital Necker-Enfants Malades, Paris, France
- Inserm U1163, Imagine Institute, Paris, France
| | - Olivia Boyer
- Hôpital Necker-Enfants malades, Néphrologie pédiatrique, Assistance Publique des Hôpitaux de Paris, Université Paris Descartes-Sorbonne Paris-Cité, Paris, France
- Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Centre de référence du syndrome néphrotique idiopathique de l'enfant et de l'adulte, Hôpital Necker-Enfants Malades, Paris, France
- Inserm U1163, Imagine Institute, Paris, France
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220
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Sagoo MK, Gnudi L. Diabetic nephropathy: Is there a role for oxidative stress? Free Radic Biol Med 2018; 116:50-63. [PMID: 29305106 DOI: 10.1016/j.freeradbiomed.2017.12.040] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/27/2017] [Accepted: 12/31/2017] [Indexed: 01/06/2023]
Abstract
Oxidative stress has been implicated in the pathophysiology of diabetic nephropathy. Studies in experimental animal models of diabetes strongly implicate oxidant species as a major determinant in the pathophysiology of diabetic kidney disease. The translation, in the clinical setting, of these concepts have been quite disappointing, and new theories have challenged the concepts that oxidative stress per se plays a role in the pathophysiology of diabetic kidney disease. The concept of mitochondrial hormesis has been introduced to explain this apparent disconnect. Hormesis is intended as any cellular process that exhibits a biphasic response to exposure to increasing amounts of a substance or condition: specifically, in diabetic kidney disease, oxidant species may represent, at determined concentration, an essential and potentially protective factor. It could be postulated that excessive production or inhibition of oxidant species formation might result in an adverse phenotype. This review discusses the evidence underlying these two apparent contradicting concepts, with the aim to propose and speculate on potential mechanisms underlying the role of oxidant species in the pathophysiology of diabetic nephropathy and possibly open future more efficient therapies to be tested in the clinical settings.
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Affiliation(s)
- Manpreet K Sagoo
- School of Cardiovascular Medicine & Sciences, British Heart Foundation Centre of Research Excellence, Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
| | - Luigi Gnudi
- School of Cardiovascular Medicine & Sciences, British Heart Foundation Centre of Research Excellence, Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK.
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221
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Muraleedharan S, Sam A, Skaer H, Inamdar MS. Networks that link cytoskeletal regulators and diaphragm proteins underpin filtration function in Drosophila nephrocytes. Exp Cell Res 2018; 364:234-242. [PMID: 29458174 PMCID: PMC5883325 DOI: 10.1016/j.yexcr.2018.02.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 02/06/2018] [Accepted: 02/15/2018] [Indexed: 11/25/2022]
Abstract
Insect nephrocytes provide a valuable model for kidney disease, as they are structurally and functionally homologous to mammalian kidney podocytes. They possess an exceptional macromolecular assembly, the nephrocyte diaphragm (ND), which serves as a filtration barrier and helps maintain tissue homeostasis by filtering out wastes and toxic products. However, the elements that maintain nephrocyte architecture and the ND are not understood. We show that Drosophila nephrocytes have a unique cytoplasmic cluster of F-actin, which is maintained by the microtubule cytoskeleton and Rho-GTPases. A balance of Rac1 and Cdc42 activity as well as proper microtubule organization and endoplasmic reticulum structure, are required to position the actin cluster. Further, ND proteins Sns and Duf also localize to this cluster and regulate organization of the actin and microtubule cytoskeleton. Perturbation of any of these inter-dependent components impairs nephrocyte ultrafiltration. Thus cytoskeletal components, Rho-GTPases and ND proteins work in concert to maintain the specialized nephrocyte architecture and function. Drosophila nephrocytes have a unique cytoplasmic cluster of F-actin. Microtubules, Rho-GTPases and endoplasmic reticulum position the actin cluster. Nephrocyte diaphragm proteins localize to and regulate actin cluster organization. Perturbation of any of these inter-dependent components impairs ultrafiltration.
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Affiliation(s)
- Simi Muraleedharan
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Aksah Sam
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Helen Skaer
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Maneesha S Inamdar
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India; Institute for Stem Cell Biology and Regenerative Medicine, GKVK, Bellary Road, Bangalore 560065, India.
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222
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Liu YC, Chun J. Prospects for Precision Medicine in Glomerulonephritis Treatment. Can J Kidney Health Dis 2018; 5:2054358117753617. [PMID: 29449955 PMCID: PMC5808958 DOI: 10.1177/2054358117753617] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 11/12/2017] [Indexed: 02/06/2023] Open
Abstract
Background: Glomerulonephritis (GN) consists of a group of kidney diseases that are categorized based on shared histopathological features. The current classifications for GN make it difficult to distinguish the individual variability in presentation, disease progression, and response to treatment. GN is a significant cause of end-stage renal disease (ESRD), and improved therapies are desperately needed because current immunosuppressive therapies sometimes lack efficacy and can lead to significant toxicities. In recent years, the combination of high-throughput genetic approaches and technological advances has identified important regulators contributing to GN. Objectives: In this review, we summarize recent findings in podocyte biology and advances in experimental approaches that have opened the possibility of precision medicine in GN treatment. We provide an integrative basic science and clinical overview of new developments in GN research and the discovery of potential candidates for targeted therapies in GN. Findings: Advances in podocyte biology have identified many candidates for therapeutic targets and potential biomarkers of glomerular disease. The goal of precision medicine in GN is now being pursued with recent technological improvements in genetics, accessibility of biologic and clinical information with tissue biobanks, high-throughput analysis of large-scale data sets, and new human model systems such as kidney organoids. Conclusion: With advances in data collection, technologies, and experimental model systems, we now have vast tools available to pursue precision medicine in GN. We anticipate a growing number of studies integrating data from high-throughput analysis with the development of diagnostic tools and targeted therapies for GN in the near future.
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Affiliation(s)
- Yulu Cherry Liu
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Justin Chun
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.,Division of Nephrology, Department of Medicine, University of Calgary, Alberta, Canada
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223
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Ma Y, Yang Q, Zhong Z, Liang W, Zhang L, Yang Y, Ding G. Role of c-Abl and nephrin in podocyte cytoskeletal remodeling induced by angiotensin II. Cell Death Dis 2018; 9:185. [PMID: 29416010 PMCID: PMC5833834 DOI: 10.1038/s41419-017-0225-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/18/2022]
Abstract
Our previous study showed that angiotensin II (Ang II) exposure diminished the interaction between nephrin and c-Abl, then c-Abl mediated SHIP2-Akt pathway in the process of podocyte injury in vivo and vitro. However, the relationship between nephrin and c-Abl was unknown. Recently, various studies showed that nephrin was required for cytoskeletal remodeling in glomerular podocytes. But its specific mechanisms remain incompletely understood. As a nonreceptor tyrosine kinase involved in cytoskeletal regulation, c-Abl may be a candidate of signaling proteins interacting with Src homology 2/3 (SH2/SH3) domains of nephrin. Therefore, it is proposed that c-Abl contributes to nephrin-dependent cytoskeletal remodeling of podocytes. Herein, we observed that nephrin-c-Abl colocalization were suppressed in glomeruli of patients with proteinuria. Next, CD16/7-nephrin and c-Abl vectors were constructed to investigate the nephrin-c-Abl signaling pathway in podocyte actin-cytoskeletal remodeling. The disorganized cytoskeleton stimulated by cytochalasin D in COS7 cells was dramatically restored by co-transfection with phosphorylated CD16/7-nephrin and c-Abl full-length constructs. Further, co-immunoprecipitation showed that phosphorylated CD16/7-nephrin interacted with wild-type c-Abl, but not with SH2/SH3-defective c-Abl. These findings suggest that phosphorylated nephrin is able to recruit c-Abl in a SH2/SH3-dependent manner and detached c-Abl from dephosphorylated nephrin contributes to cytoskeletal remodeling in podocytes.
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Affiliation(s)
- Yiqiong Ma
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Qian Yang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Zhentong Zhong
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Wei Liang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Lu Zhang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Yingjie Yang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Guohua Ding
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China.
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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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225
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GOHDA TOMOHITO, SUZUKI HITOSHI, HIDAKA TERUO, UEDA SEIJI, SUZUKI YUSUKE. An Update of Pathogenesis and Treatment in Patients with Chronic Kidney Disease (CKD) and Cardio-Renal Syndrome. JUNTENDO MEDICAL JOURNAL 2018. [DOI: 10.14789/jmj.2018.64.jmj18-ln02] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- TOMOHITO GOHDA
- Department of Nephrology, Juntendo University Faculty of Medicine
| | - HITOSHI SUZUKI
- Department of Nephrology, Juntendo University Faculty of Medicine
| | - TERUO HIDAKA
- Department of Nephrology, Juntendo University Faculty of Medicine
| | - SEIJI UEDA
- Department of Nephrology, Juntendo University Faculty of Medicine
| | - YUSUKE SUZUKI
- Department of Nephrology, Juntendo University Faculty of Medicine
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226
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Martin CE, Jones N. Nephrin Signaling in the Podocyte: An Updated View of Signal Regulation at the Slit Diaphragm and Beyond. Front Endocrinol (Lausanne) 2018; 9:302. [PMID: 29922234 PMCID: PMC5996060 DOI: 10.3389/fendo.2018.00302] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 05/22/2018] [Indexed: 12/11/2022] Open
Abstract
Podocytes are a major component of the glomerular blood filtration barrier, and alterations to the morphology of their unique actin-based foot processes (FP) are a common feature of kidney disease. Adjacent FP are connected by a specialized intercellular junction known as the slit diaphragm (SD), which serves as the ultimate barrier to regulate passage of macromolecules from the blood. While the link between SD dysfunction and reduced filtration selectivity has been recognized for nearly 50 years, our understanding of the underlying molecular circuitry began only 20 years ago, sparked by the identification of NPHS1, encoding the transmembrane protein nephrin. Nephrin not only functions as the core component of the extracellular SD filtration network but also as a signaling scaffold via interactions at its short intracellular region. Phospho-regulation of several conserved tyrosine residues in this region influences signal transduction pathways which control podocyte cell adhesion, shape, and survival, and emerging studies highlight roles for nephrin phospho-dynamics in mechanotransduction and endocytosis. The following review aims to summarize the last 5 years of advancement in our knowledge of how signaling centered at nephrin directs SD barrier formation and function. We further provide insight on promising frontiers in podocyte biology, which have implications for SD signaling in the healthy and diseased kidney.
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227
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Varner JD, Chryst-Stangl M, Esezobor CI, Solarin A, Wu G, Lane B, Hall G, Abeyagunawardena A, Matory A, Hunley TE, Lin JJ, Howell D, Gbadegesin R. Genetic Testing for Steroid-Resistant-Nephrotic Syndrome in an Outbred Population. Front Pediatr 2018; 6:307. [PMID: 30406062 PMCID: PMC6204400 DOI: 10.3389/fped.2018.00307] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 10/01/2018] [Indexed: 12/12/2022] Open
Abstract
Background: Steroid-resistant nephrotic syndrome (SRNS) is a leading cause of end-stage kidney disease in children and young adults. Despite advances in genomic science that have led to the discovery of >50 monogenic causes of SRNS, there are no clear guidelines for genetic testing in clinical practice. Methods: Using high throughput sequencing, we evaluated 492 individuals from 181 families for mutations in 40 known SRNS genes. Causative mutations were defined as missense, truncating, and obligatory splice site variants with a minor allele frequency <1% in controls. Non-synonymous variants were considered pathogenic if determined to be deleterious by at least two in silico models. We further evaluated for differences in age at disease onset, family history of SRNS or chronic kidney disease, race, sex, renal biopsy findings, and extra-renal manifestations in subgroups with and without disease causing variants. Results: We identified causative variants in 40 of 181 families (22.1%) with SRNS. Variants in INF2, COL4A3, and WT1 were the most common, accounting for over half of all causative variants. Causative variants were identified in 34 of 86 families (39.5%) with familial disease and 6 of 95 individuals (6.3%) with sporadic disease (χ2 p < 0.00001). Family history was the only significant clinical predictor of genetic SRNS. Conclusion: We identified causative mutations in almost 40% of all families with hereditary SRNS and 6% of individuals with sporadic disease, making family history the single most important clinical predictors of monogenic SRNS. We recommend genetic testing in all patients with SRNS and a positive family history, but only selective testing in those with sporadic disease.
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Affiliation(s)
- Jennifer D Varner
- Division of Nephrology, Departments of Pediatrics and Medicine, Duke University Medical Center, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | - Megan Chryst-Stangl
- Division of Nephrology, Departments of Pediatrics and Medicine, Duke University Medical Center, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | | | - Adaobi Solarin
- Department of Pediatrics, Lagos State University Teaching Hospital, Ikeja, Nigeria
| | - Guanghong Wu
- Division of Nephrology, Departments of Pediatrics and Medicine, Duke University Medical Center, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | - Brandon Lane
- Division of Nephrology, Departments of Pediatrics and Medicine, Duke University Medical Center, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | - Gentzon Hall
- Division of Nephrology, Departments of Pediatrics and Medicine, Duke University Medical Center, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | | | - Ayo Matory
- Division of Nephrology, Departments of Pediatrics and Medicine, Duke University Medical Center, Durham, NC, United States
| | - Tracy E Hunley
- Division of Nephrology, Department of Pediatrics, Vanderbilt University, Nashville, TN, United States
| | - Jen Jar Lin
- Department of Pediatrics, Wake Forest Baptist Medical Center, Winston Salem, NC, United States
| | - David Howell
- Department of Pathology, Duke University Medical Center, Durham, NC, United States
| | - Rasheed Gbadegesin
- Division of Nephrology, Departments of Pediatrics and Medicine, Duke University Medical Center, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
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228
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Lay AC, Coward RJM. The Evolving Importance of Insulin Signaling in Podocyte Health and Disease. Front Endocrinol (Lausanne) 2018; 9:693. [PMID: 30524379 PMCID: PMC6258712 DOI: 10.3389/fendo.2018.00693] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/05/2018] [Indexed: 12/17/2022] Open
Abstract
Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease worldwide, occuring in approximately one-third of diabetic patients. One of the earliest hallmarks of DKD is albuminuria, often occurring following disruptions to the glomerular filtration barrier. Podocytes are highly specialized cells with a central role in filtration barrier maintenance; hence, podocyte dysfunction is a major cause of albuminuria in many settings, including DKD. Numerous studies over the last decade have highlighted the importance of intact podocyte insulin responses in the maintenance of podocyte function. This review summarizes our current perspectives on podocyte insulin signaling, highlighting evidence to support the notion that dysregulated podocyte insulin responses contribute toward podocyte damage, particularly during the pathogenesis of DKD.
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229
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Kang HG, Lee M, Lee KB, Hughes M, Kwon BS, Lee S, McNagny KM, Ahn YH, Ko JM, Ha IS, Choi M, Cheong HI. Loss of podocalyxin causes a novel syndromic type of congenital nephrotic syndrome. Exp Mol Med 2017; 49:e414. [PMID: 29244787 PMCID: PMC5750479 DOI: 10.1038/emm.2017.227] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/01/2017] [Accepted: 07/11/2017] [Indexed: 01/09/2023] Open
Abstract
Many cellular structures directly imply specific biological functions. For example, normal slit diaphragm structures that extend from podocyte foot processes ensure the filtering function of renal glomeruli. These slits are covered by a number of surface proteins, such as nephrin, podocin, podocalyxin and CD2AP. Here we report a human patient presenting with congenital nephrotic syndrome, omphalocele and microcoria due to two loss-of-function mutations in PODXL, which encodes podocalyxin, inherited from each parent. This set of symptoms strikingly mimics previously reported mouse Podxl−/− embryos, emphasizing the essential function of PODXL in mammalian kidney development and highlighting this patient as a human PODXL-null model. The results underscore the utility of current genomics approaches to provide insights into the genetic mechanisms of human disease traits through molecular diagnosis.
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Affiliation(s)
- Hee Gyung Kang
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.,Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Republic of Korea
| | - Moses Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Kyoung Boon Lee
- Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Michael Hughes
- The Biomedical Research Centre, The University of British Colombia, Vancouver, British Columbia, Canada
| | - Bo Sang Kwon
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sangmoon Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Kelly M McNagny
- The Biomedical Research Centre, The University of British Colombia, Vancouver, British Columbia, Canada
| | - Yo Han Ahn
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.,Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jung Min Ko
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.,Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Republic of Korea
| | - Il-Soo Ha
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.,Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Murim Choi
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea.,Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hae Il Cheong
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.,Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Republic of Korea.,Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Republic of Korea
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230
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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: 10] [Impact Index Per Article: 1.4] [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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231
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Hamasaki Y, Muramatsu M, Hamada R, Ishikura K, Hataya H, Satou H, Honda M, Nakanishi K, Shishido S. Long-term outcome of congenital nephrotic syndrome after kidney transplantation in Japan. Clin Exp Nephrol 2017; 22:719-726. [PMID: 29185126 DOI: 10.1007/s10157-017-1508-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 11/09/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND Congenital nephrotic syndrome is difficult to manage, particularly the Finnish type (CNF), with patients experiencing severe edema, sepsis and thrombosis before kidney transplantation. Further, nephrosis and thrombosis remain problematic after transplantation. METHODS Of 22 CNF patients managed at our hospital, 14 who underwent kidney transplantation were retrospectively studied. CNF was diagnosed according to standard criteria. RESULTS The study population consisted of 3 males and 11 females. Mean gestation period was 36 ± 1.4 weeks and mean birth weight was 2442 ± 454 g (mean placenta to body weight ratio: 0.4). All patients started dialysis at 2.4 ± 1.3 years and underwent kidney transplantation at 5.2 ± 2.0 years. The kidneys were donated by the parents (n = 13), and cadaver (n = 2), including overlap. Mean follow-up period after transplantation was 14.3 ± 8.9 years, and mean age at last observation was 19.5 ± 8.5 years. Two patients had recurrent proteinuria after kidney transplantation; one underwent retransplantation following graft failure and eventually required dialysis, while the second had complete remission after intensive immunosuppressive therapy. There were no cases of thrombosis or serious infections. Mean eGFR at the time of last observation was 57.3 ± 16.5 ml/min/1.73 m2, while mean height SD score was - 2.1 ± 0.9 at the time of transplantation and - 1.5 ± 1.5 at last observation. CONCLUSIONS Long-term outcome in these 14 CNF patients showed satisfactory graft survival, improved height SD score, and favorable development. Although recurrent proteinuria after transplant was not predictive, it was associated with graft survival rate.
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Affiliation(s)
- Yuko Hamasaki
- Department of Pediatric Nephrology, Toho University Faculty of Medicine, 6-11-1 Omori-Nishi, Ota-Ku, Tokyo, 143-8541, Japan. .,Department of Nephrology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.
| | - Masaki Muramatsu
- Department of Nephrology, Toho University Faculty of Medicine, Tokyo, Japan
| | - Riku Hamada
- Department of Nephrology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Kenji Ishikura
- Department of Nephrology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.,Division of Nephrology and Rheumatology, National Center for Child Health and Development, Tokyo, Japan
| | - Hiroshi Hataya
- Department of Nephrology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.,Department of General Pediatrics, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Hiroyuki Satou
- Department of Urology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Masataka Honda
- Department of Nephrology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Koichi Nakanishi
- Department of Child Health and Welfare (Pediatrics), Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Seiichiro Shishido
- Department of Pediatric Nephrology, Toho University Faculty of Medicine, 6-11-1 Omori-Nishi, Ota-Ku, Tokyo, 143-8541, Japan.,Department of Nephrology, Toho University Faculty of Medicine, Tokyo, Japan
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232
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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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233
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Acute Exposure to Cigarette Smoking Followed by Myocardial Infarction Aggravates Renal Damage in an In Vivo Mouse Model. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:5135241. [PMID: 29177025 PMCID: PMC5671747 DOI: 10.1155/2017/5135241] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/06/2017] [Accepted: 09/19/2017] [Indexed: 12/24/2022]
Abstract
Cigarette smoking (S) is a risk factor for progressive chronic kidney disease, renal dysfunction, and renal failure. In this study, the effect of smoking on kidney function was investigated in a mouse model of myocardial infarction (MI) using 4 groups: control (C), smoking (S), MI, and S+MI. Histological analysis of S+MI group showed alterations in kidney structure including swelling of the proximal convoluted tubules (PCTs), thinning of the epithelial lining, focal loss of the brush border of PCTs, and patchy glomerular retraction. Molecular analysis revealed that nephrin expression was significantly reduced in the S+MI group, whereas sodium-hydrogen exchanger-1 (NHE-1) was significantly increased, suggesting altered glomerular filtration and kidney functions. Moreover, S+MI group, but not S alone, showed a significant increase in the expression of connective tissue growth factor (CTGF) and fibrotic proteins fibronectin (FN) and α-smooth muscle actin (SMA), in comparison to controls, in addition to a significant increase in mRNA levels of IL-6 and TNF-α inflammatory markers. Finally, reactive oxygen species (ROS) production was significantly accentuated in S+MI group concomitant with a significant increase in NOX-4 protein levels. In conclusion, smoking aggravates murine acute renal damage caused by MI at the structural and molecular levels by exacerbating renal dysfunction.
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234
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Kim YK, Refaeli I, Brooks CR, Jing P, Gulieva RE, Hughes MR, Cruz NM, Liu Y, Churchill AJ, Wang Y, Fu H, Pippin JW, Lin LY, Shankland SJ, Vogl AW, McNagny KM, Freedman BS. Gene-Edited Human Kidney Organoids Reveal Mechanisms of Disease in Podocyte Development. Stem Cells 2017; 35:2366-2378. [PMID: 28905451 DOI: 10.1002/stem.2707] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 09/04/2017] [Indexed: 11/07/2022]
Abstract
A critical event during kidney organogenesis is the differentiation of podocytes, specialized epithelial cells that filter blood plasma to form urine. Podocytes derived from human pluripotent stem cells (hPSC-podocytes) have recently been generated in nephron-like kidney organoids, but the developmental stage of these cells and their capacity to reveal disease mechanisms remains unclear. Here, we show that hPSC-podocytes phenocopy mammalian podocytes at the capillary loop stage (CLS), recapitulating key features of ultrastructure, gene expression, and mutant phenotype. hPSC-podocytes in vitro progressively establish junction-rich basal membranes (nephrin+ podocin+ ZO-1+ ) and microvillus-rich apical membranes (podocalyxin+ ), similar to CLS podocytes in vivo. Ultrastructural, biophysical, and transcriptomic analysis of podocalyxin-knockout hPSCs and derived podocytes, generated using CRISPR/Cas9, reveals defects in the assembly of microvilli and lateral spaces between developing podocytes, resulting in failed junctional migration. These defects are phenocopied in CLS glomeruli of podocalyxin-deficient mice, which cannot produce urine, thereby demonstrating that podocalyxin has a conserved and essential role in mammalian podocyte maturation. Defining the maturity of hPSC-podocytes and their capacity to reveal and recapitulate pathophysiological mechanisms establishes a powerful framework for studying human kidney disease and regeneration. Stem Cells 2017;35:2366-2378.
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Affiliation(s)
- Yong Kyun Kim
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Kidney Research Institute, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Institute for Stem Cell and Regenerative Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Ido Refaeli
- The Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Craig R Brooks
- Division of Nephrology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Peifeng Jing
- Department of Electrical Engineering, University of Washington, Seattle, Washington, USA
| | - Ramila E Gulieva
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Kidney Research Institute, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Institute for Stem Cell and Regenerative Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Michael R Hughes
- The Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nelly M Cruz
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Kidney Research Institute, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Institute for Stem Cell and Regenerative Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Yannan Liu
- Department of Electrical Engineering, University of Washington, Seattle, Washington, USA
| | - Angela J Churchill
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Kidney Research Institute, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Institute for Stem Cell and Regenerative Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Yuliang Wang
- Institute for Stem Cell and Regenerative Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, Washington, USA
| | - Hongxia Fu
- Institute for Stem Cell and Regenerative Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Bioengineering, University of Washington School of Medicine, Seattle, Washington, USA
| | - Jeffrey W Pippin
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Lih Y Lin
- Department of Electrical Engineering, University of Washington, Seattle, Washington, USA
| | - Stuart J Shankland
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - A Wayne Vogl
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kelly M McNagny
- The Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Benjamin S Freedman
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Kidney Research Institute, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Institute for Stem Cell and Regenerative Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
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van de Lest NA, Zandbergen M, IJpelaar DHT, Wolterbeek R, Bruijn JA, Bajema IM, Scharpfenecker M. Nephrin Loss Can Be Used to Predict Remission and Long-term Renal Outcome in Patients With Minimal Change Disease. Kidney Int Rep 2017; 3:168-177. [PMID: 29340328 PMCID: PMC5762955 DOI: 10.1016/j.ekir.2017.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/30/2017] [Accepted: 09/18/2017] [Indexed: 11/16/2022] Open
Abstract
Introduction Minimal change disease is a common cause of nephrotic syndrome. In general, patients with minimal change disease respond to corticosteroids and have excellent long-term renal survival. However, some patients have less favorable outcome. These patients are often thought to have progressed to focal segmental glomerulosclerosis. We previously reported that a segmental loss of podocyte markers is present before the development of focal segmental glomerulosclerosis in a rat model. Here, we investigated whether loss of podocyte marker nephrin can serve as a biomarker for predicting poor outcome in patients with minimal change disease. Methods We obtained 47 kidney biopsy samples from patients diagnosed with minimal change disease and stained sections with periodic acid−Schiff and for nephrin. Nephrin loss was scored by 2 independent researchers who were blinded to clinical outcome. Clinical data were collected retrospectively, and nephrin loss was correlated with clinical follow-up data. Results Nephrin loss was present in 34% of the biopsy samples. During follow-up, patients with nephrin loss achieved remission less frequently (61%) compared to patients without (96%) (P = 0.002). Moreover, 5-year eGFR was lower in the patients with renal nephrin loss. The risk of eGFR decreasing to < 60 ml/min per 1.73m2 increased with each percentage of glomeruli with nephrin loss (hazard ratio = 1.044, 95% confidence interval = 1.02−1.07). Conclusion These results indicate that nephrin loss in patients with minimal change disease can help predict both remission and long-term renal outcome.
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Affiliation(s)
- Nina A van de Lest
- Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
| | - Malu Zandbergen
- Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
| | - Daphne H T IJpelaar
- Department of Nephrology, Leiden University Medical Center, Leiden, the Netherlands
| | - Ron Wolterbeek
- Department of Medical Statistics, Leiden University Medical Center, Leiden, the Netherlands
| | - Jan A Bruijn
- Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
| | - Ingeborg M Bajema
- Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
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ARF6 mediates nephrin tyrosine phosphorylation-induced podocyte cellular dynamics. PLoS One 2017; 12:e0184575. [PMID: 28880939 PMCID: PMC5589247 DOI: 10.1371/journal.pone.0184575] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/26/2017] [Indexed: 01/10/2023] Open
Abstract
ADP-ribosylation factor 6 (ARF6) is a small GTPase necessary for regulating cellular structure, motility, and vesicle trafficking. In several cellular systems, ARF6 was shown to regulate actin dynamics in coordination with Rac1, a Rho small GTPase. We examined the function of ARF6 in the kidney podocyte because Rac1 was implicated in kidney diseases involving this cell. We found that ARF6 expression was enriched in human podocytes and that it modulated podocyte cytoskeletal dynamics through a functional interaction with nephrin, an intercellular junction protein necessary for podocyte injury-induced signaling requiring activation by tyrosine phosphorylation of its cytoplasmic domain. ARF6 was necessary for nephrin activation-induced ruffling and focal adhesion turnover, possibly by altering Rac1 activity. In podocyte-specific Arf6 (ARF6_PodKO) knockout mice, ARF6 deficiency did not result in a spontaneous kidney developmental phenotype or proteinuria after aging. However, ARF6_PodKO mice exhibited distinct phenotypes in two in vivo glomerular injury models. In the protamine sulfate perfusion model, which induced acute podocyte effacement, ARF6_PodKO mice were protected from podocyte effacement. In the nephrotoxic serum nephritis model, which induced immune-complex mediated injury, ARF6_PodKO mice exhibited aggravated proteinuria. Together, these observations suggest that while ARF6 is necessary for nephrin tyrosine phosphorylation-induced cytoskeletal dynamics in cultured podocytes, ARF6 has pleotropic podocyte roles in vivo, where glomerular injury-specific mechanisms might activate distinct signaling pathways that dictate whether ARF6 activity is beneficial or deleterious for maintaining the integrity of the glomerular filtration barrier.
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Multiple Targets for Novel Therapy of FSGS Associated with Circulating Permeability Factor. BIOMED RESEARCH INTERNATIONAL 2017; 2017:6232616. [PMID: 28951873 PMCID: PMC5603123 DOI: 10.1155/2017/6232616] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 05/10/2017] [Accepted: 06/15/2017] [Indexed: 01/13/2023]
Abstract
A plasma component is responsible for altered glomerular permeability in patients with focal segmental glomerulosclerosis. Evidence includes recurrence after renal transplantation, remission after plasmapheresis, proteinuria in infants of affected mothers, transfer of proteinuria to experimental animals, and impaired glomerular permeability after exposure to patient plasma. Therapy may include decreasing synthesis of the injurious agent, removing or blocking its interaction with cells, or blocking signaling or enhancing cell defenses to restore the permeability barrier and prevent progression. Agents that may prevent the synthesis of the permeability factor include cytotoxic agents or aggressive chemotherapy. Extracorporeal therapies include plasmapheresis, immunoadsorption with protein A or anti-immunoglobulin, or lipopheresis. Oral or intravenous galactose also decreases Palb activity. Studies of glomeruli have shown that several strategies prevent the action of FSGS sera. These include blocking receptor-ligand interactions, modulating cell reactions using indomethacin or eicosanoids 20-HETE or 8,9-EET, and enhancing cytoskeleton and protein interactions using calcineurin inhibitors, glucocorticoids, or rituximab. We have identified cardiotrophin-like cytokine factor 1 (CLCF-1) as a candidate for the permeability factor. Therapies specific to CLCF-1 include potential use of cytokine receptor-like factor (CRLF-1) and inhibition of Janus kinase 2. Combined therapy using multiple modalities offers therapy to reverse proteinuria and prevent scarring.
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Kostovska I, Trajkovska KT, Cekovska S, Spasovski G, Labudovic D. Nephrin and Podocalyxin - New Podocyte Proteins for Early Detection of Secondary Nephropathies. BANTAO JOURNAL 2017. [DOI: 10.1515/bj-2016-0003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Abstract
In the last two decades a great progress was observed in understanding of podocytes, their specific structure and function identifying many specific podocyte proteins, such as nephrin and podocalyxin. Podocytes form the final barrier to plasma proteins leakage. Nephrin as a main component of the filtration diaphragm forms a physical barrier while podocalyxin as sialoglycoprotein forms an electrostatic barrier. Podocyte damage, i.e. podocytopathies and their loss through urine-podocyturia, are crucial in pathogenesis and progression of nephropathies with proteinuria as main clinical manifestation. In podocytopathies, nephrin and podocalyxin appear in the urine before proteinuria and microalbuminuria which were previously considered as earliest markers of nephropathies. Nephrinuria and podocalyxuria indicate damage of the podocytes on glomerular level and/or presence of apoptotic and necrotic podocytes in urine. These urinary markers are also important in early diagnosis of secondary nephropathies such as diabetic, lupus and hypertensive nephropathy as the most common causes of end-stage renal failure (ESRF). These markers are also important in the prediction of preeclampsia, which is the most common complication in pregnancy. In this review we elaborate in dept the main structural and functional features of podocytes and their specific proteins, nephrin and podocalyxin, summarizing the recent literature data on their importance in the early diagnosis of the most common secondary nephropathies.
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Affiliation(s)
- Irena Kostovska
- Department of Medical and Experimental Biochemistry, Skopje , Republic of Macedonia
| | | | - Svetlana Cekovska
- Department of Medical and Experimental Biochemistry, Skopje , Republic of Macedonia
| | - Goce Spasovski
- Department of Nephrology, Medical Faculty, Skopje, University "Ss Cyril and Methodius", Skopje , Republic of Macedonia
| | - Danica Labudovic
- Department of Medical and Experimental Biochemistry, Skopje , Republic of Macedonia
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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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Rinschen MM, Hoppe AK, Grahammer F, Kann M, Völker LA, Schurek EM, Binz J, Höhne M, Demir F, Malisic M, Huber TB, Kurschat C, Kizhakkedathu JN, Schermer B, Huesgen PF, Benzing T. N-Degradomic Analysis Reveals a Proteolytic Network Processing the Podocyte Cytoskeleton. J Am Soc Nephrol 2017; 28:2867-2878. [PMID: 28724775 DOI: 10.1681/asn.2016101119] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 05/08/2017] [Indexed: 11/03/2022] Open
Abstract
Regulated intracellular proteostasis, controlled in part by proteolysis, is essential in maintaining the integrity of podocytes and the glomerular filtration barrier of the kidney. We applied a novel proteomics technology that enables proteome-wide identification, mapping, and quantification of protein N-termini to comprehensively characterize cleaved podocyte proteins in the glomerulus in vivo We found evidence that defined proteolytic cleavage results in various proteoforms of important podocyte proteins, including those of podocin, nephrin, neph1, α-actinin-4, and vimentin. Quantitative mapping of N-termini demonstrated perturbation of protease action during podocyte injury in vitro, including diminished proteolysis of α-actinin-4. Differentially regulated protease substrates comprised cytoskeletal proteins as well as intermediate filaments. Determination of preferential protease motifs during podocyte damage indicated activation of caspase proteases and inhibition of arginine-specific proteases. Several proteolytic processes were clearly site-specific, were conserved across species, and could be confirmed by differential migration behavior of protein fragments in gel electrophoresis. Some of the proteolytic changes discovered in vitro also occurred in two in vivo models of podocyte damage (WT1 heterozygous knockout mice and puromycin aminonucleoside-treated rats). Thus, we provide direct and systems-level evidence that the slit diaphragm and podocyte cytoskeleton are regulated targets of proteolytic modification, which is altered upon podocyte damage.
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Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC).,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Ann-Kathrin Hoppe
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Florian Grahammer
- Department of Medicine III, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Medicine IV, Medical Center and Faculty of Medicine - University of Freiburg, Freiburg, Germany
| | - Martin Kann
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Linus A Völker
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Eva-Maria Schurek
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Julie Binz
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Martin Höhne
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC).,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Fatih Demir
- Central Institute for Engineering, Electronics and Analytics, ZEA-3, Forschungszentrum Jülich, Jülich, Germany
| | - Milena Malisic
- Central Institute for Engineering, Electronics and Analytics, ZEA-3, Forschungszentrum Jülich, Jülich, Germany
| | - Tobias B Huber
- Department of Medicine III, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Medicine IV, Medical Center and Faculty of Medicine - University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies and Center for Biological Systems Analysis (ZBSA), Albert-Ludwigs-University, Freiburg, Germany; and
| | - Christine Kurschat
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Jayachandran N Kizhakkedathu
- Centre for Blood Research, Department of Pathology and Laboratory Medicine, Department of Chemistry, University of British Columbia, Vancouver, Canada
| | - Bernhard Schermer
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC).,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Pitter F Huesgen
- Central Institute for Engineering, Electronics and Analytics, ZEA-3, Forschungszentrum Jülich, Jülich, Germany;
| | - Thomas Benzing
- Department II of Internal Medicine, .,Center for Molecular Medicine Cologne (CMMC).,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
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Helm BM, Willer JR, Sadeghpour A, Golzio C, Crouch E, Vergano SS, Katsanis N, Davis EE. Partial uniparental isodisomy of chromosome 16 unmasks a deleterious biallelic mutation in IFT140 that causes Mainzer-Saldino syndrome. Hum Genomics 2017; 11:16. [PMID: 28724397 PMCID: PMC5517791 DOI: 10.1186/s40246-017-0111-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/29/2017] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The ciliopathies represent an umbrella group of >50 clinical entities that share both clinical features and molecular etiology underscored by structural and functional defects of the primary cilium. Despite the advances in gene discovery, this group of entities continues to pose a diagnostic challenge, in part due to significant genetic and phenotypic heterogeneity and variability. We consulted a pediatric case from asymptomatic, non-consanguineous parents who presented as a suspected ciliopathy due to a constellation of retinal, renal, and skeletal findings. RESULTS Although clinical panel sequencing of genes implicated in nephrotic syndromes yielded no likely causal mutation, an oligo-SNP microarray identified a ~20-Mb region of homozygosity, with no altered gene dosage, on chromosome 16p13. Intersection of the proband's phenotypes with known disease genes within the homozygous region yielded a single candidate, IFT140, encoding a retrograde intraflagellar transport protein implicated previously in several ciliopathies, including the phenotypically overlapping Mainzer-Saldino syndrome (MZSDS). Sanger sequencing yielded a maternally inherited homozygous c.634G>A; p.Gly212Arg mutation altering the exon 6 splice donor site. Functional studies in cells from the proband showed that the locus produced two transcripts: a majority message containing a mis-splicing event that caused a premature termination codon and a minority message homozygous for the p.Gly212Arg allele. Zebrafish in vivo complementation studies of the latter transcript demonstrated a loss of function effect. Finally, we conducted post-hoc trio-based whole exome sequencing studies to (a) test the possibility of other causal loci in the proband and (b) explain the Mendelian error of segregation for the IFT140 mutation. We show that the proband harbors a chromosome 16 maternal heterodisomy, with segmental isodisomy at 16p13, likely due to a meiosis I error in the maternal gamete. CONCLUSIONS Using clinical phenotyping combined with research-based genetic and functional studies, we have characterized a recurrent IFT140 mutation in the proband; together, these data are consistent with MZSDS. Additionally, we report a rare instance of a uniparental isodisomy unmasking a deleterious mutation to cause a ciliary disorder.
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Affiliation(s)
- Benjamin M Helm
- Division of Medical Genetics and Metabolism, Children's Hospital of The King's Daughters, Norfolk, VA, 23507, USA.,Department of Medical & Molecular Genetics, Riley Hospital for Children at IU Health, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Jason R Willer
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, 27701, USA
| | - Azita Sadeghpour
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, 27701, USA
| | - Christelle Golzio
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, 27701, USA.,Institute of Genetics and Molecular and Cellular Biology, 67404, Illkirch, France
| | - Eric Crouch
- Department of Ophthalmology, Children's Hospital of the King's Daughters, Norfolk, VA, 23507, USA
| | - Samantha Schrier Vergano
- Division of Medical Genetics and Metabolism, Children's Hospital of The King's Daughters, Norfolk, VA, 23507, USA.,Department of Pediatrics, Eastern Virginia Medical School, Norfolk, VA, 23507, USA
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, 27701, USA.
| | - Erica E Davis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, 27701, USA.
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Nagai K, Tominaga T, Ueda S, Shibata E, Tamaki M, Matsuura M, Kishi S, Murakami T, Moriya T, Abe H, Doi T. Mesangial Cell Mammalian Target of Rapamycin Complex 1 Activation Results in Mesangial Expansion. J Am Soc Nephrol 2017; 28:2879-2885. [PMID: 28701517 DOI: 10.1681/asn.2016111196] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 06/02/2017] [Indexed: 02/05/2023] Open
Abstract
Human glomerular diseases can be caused by several different diseases, many of which include mesangial expansion and/or proliferation followed by glomerulosclerosis. However, molecular mechanisms underlying the pathologic mesangial changes remain poorly understood. Here, we investigated the role of the mammalian target of rapamycin complex 1 (mTORC1)-S6 kinase pathway in mesangial expansion and/or proliferation by ablating an upstream negative regulator, tuberous sclerosis complex 1 (TSC1), using tamoxifen-induced Foxd1-Cre mice [Foxd1ER(+) TSC1 mice]. Foxd1ER(+) TSC1 mice showed mesangial expansion with increased production of collagen IV, collagen I, and α-smooth muscle actin in glomeruli, but did not exhibit significant mesangial proliferation or albuminuria. Furthermore, rapamycin treatment of Foxd1ER(+) TSC1 mice suppressed mesangial expansion. Among biopsy specimens from patients with glomerular diseases, analysis of phosphorylated ribosomal protein S6 revealed mesangial cell mTORC1 activation in IgA nephropathy and in lupus mesangial proliferative nephritis but not in the early phase of diabetic nephropathy. In summary, mesangial cell mTORC1 activation can cause mesangial expansion and has clinical relevance for human glomerular diseases. This report also confirms that the tamoxifen-induced mesangium-specific Cre-loxP system is useful for studies designed to clarify the role of the mesangium in glomerular diseases in adults.
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Affiliation(s)
- Kojiro Nagai
- Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; and
| | - Tatsuya Tominaga
- Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; and
| | - Sayo Ueda
- Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; and
| | - Eriko Shibata
- Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; and
| | - Masanori Tamaki
- Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; and
| | - Motokazu Matsuura
- Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; and
| | - Seiji Kishi
- Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; and
| | - Taichi Murakami
- Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; and
| | - Tatsumi Moriya
- Health Care Center, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Hideharu Abe
- Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; and
| | - Toshio Doi
- Department of Nephrology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan; and
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Wang F, Zhang Y, Mao J, Yu Z, Yi Z, Yu L, Sun J, Wei X, Ding F, Zhang H, Xiao H, Yao Y, Tan W, Lovric S, Ding J, Hildebrandt F. Spectrum of mutations in Chinese children with steroid-resistant nephrotic syndrome. Pediatr Nephrol 2017; 32:1181-1192. [PMID: 28204945 PMCID: PMC5478193 DOI: 10.1007/s00467-017-3590-y] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 12/06/2016] [Accepted: 12/23/2016] [Indexed: 01/21/2023]
Abstract
BACKGROUND The aim of this study was to elucidate whether genetic screening test results of pediatric patients with steroid-resistant nephrotic syndrome (SRNS) vary with ethnicity. METHODS Using high-throughput DNA sequencing, 28 nephrotic syndrome-related genes were analyzed in 110 chil-dren affected by SRNS and 10 children with isolated proteinuria enrolled by 5 centers in China (67 boys, 53 girls). Their age at disease onset ranged from 1 day to 208 months (median, 48.8 months). Patients were excluded if their age at onset of disease was over 18 years or if they were diagnosed as having Alport syndrome. RESULTS A genetic etiology was identified in 28.3% of our cohort and the likelihood of establishing a genetic diagnosis decreased as the age at onset of nephrotic syndrome increased. The most common mutated genes were ADCK4 (6.67%), NPHS1 (5.83%), WT1 (5.83%), and NPHS2 (3.33%), and the difference in the frequencies of ADCK4 and NPHS2 mutations between this study and a study on monogenic causes of SRNS in the largest international cohort of 1,783 different families was significant. A case of congenital nephrotic syndrome was attributed to a homozygous missense mutation in ADCK4, and a de novo missense mutation in TRPC6 was detected in a case of infantile nephrotic syndrome. CONCLUSIONS Our results showed that, in the first and the largest multicenter cohort of Chinese pediatric SRNS reported to date, ADCK4 is the most common causative gene, whereas there is a low prevalence of NPHS2 mutations. Our data indicated that the genetic testing results for pediatric SRNS patients vary with different ethnicities, and this information will help to improve management of the disease in clinical practice.
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Affiliation(s)
- Fang Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, P. R. China
| | - Yanqin Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, P. R. China
| | - Jianhua Mao
- Department of Nephrology, The Children Hospital of Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Zihua Yu
- Department of Pediatrics, Fuzhou Dongfang Hospital, Fuzhou, P. R. China
| | - Zhuwen Yi
- Department of Pediatrics, The second Xiangya Hospital, Central South University, Changsha, P. R. China
| | - Li Yu
- Department of Pediatrics, Guangzhou First People’s Hospital, Guangzhou, P. R. China
| | - Jun Sun
- Binhai Genomics Institute, Tianjin Translational Genomics Center, BGI-Tianjin, BGI-shenzhen, Tianjin, P. R. China,BGI-Shenzhen, Shenzhen, P. R. China
| | - Xiuxiu Wei
- Binhai Genomics Institute, Tianjin Translational Genomics Center, BGI-Tianjin, BGI-shenzhen, Tianjin, P. R. China,BGI-Shenzhen, Shenzhen, P. R. China
| | - Fangrui Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, P. R. China
| | - Hongwen Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, P. R. China
| | - Huijie Xiao
- Department of Pediatrics, Peking University First Hospital, Beijing, P. R. China
| | - Yong Yao
- Department of Pediatrics, Peking University First Hospital, Beijing, P. R. China
| | - Weizhen Tan
- Division of Nephrology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Svjetlana Lovric
- Division of Nephrology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, No. 1, Xi An Men Da Jie, Beijing, 100034, People's Republic of China.
| | - Friedhelm Hildebrandt
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Enders 561, Boston, MA, 02115, USA.
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Bornelöv S, Seroussi E, Yosefi S, Pendavis K, Burgess SC, Grabherr M, Friedman-Einat M, Andersson L. Correspondence on Lovell et al.: identification of chicken genes previously assumed to be evolutionarily lost. Genome Biol 2017; 18:112. [PMID: 28615067 PMCID: PMC5470226 DOI: 10.1186/s13059-017-1231-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Through RNA-Seq analyses, we identified 137 genes that are missing in chicken, including the long-sought-after nephrin and tumor necrosis factor genes. These genes tended to cluster in GC-rich regions that have poor coverage in genome sequence databases. Hence, the occurrence of syntenic groups of vertebrate genes that have not been observed in Aves does not prove the evolutionary loss of such genes.Please see related Research article: http://dx.doi.org/10.1186/s13059-014-0565-1 and Please see response from Lovell et al: https://www.dx.doi.org/10.1186/s13059-017-1234-y.
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Affiliation(s)
- Susanne Bornelöv
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, SE-751 23, Sweden.,Present Address: Wellcome Trust Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, CB2 1QR, UK
| | - Eyal Seroussi
- Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Sara Yosefi
- Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Ken Pendavis
- College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ, 85721-0036, USA
| | - Shane C Burgess
- College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ, 85721-0036, USA
| | - Manfred Grabherr
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, SE-751 23, Sweden.,Bioinformatics Infrastructure for Life Sciences, Uppsala University, Uppsala, Sweden
| | | | - Leif Andersson
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, SE-751 23, Sweden. .,Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, SE-750 07, Sweden. .,Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4458, USA.
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Hofmeister AF, Kömhoff M, Weber S, Grgic I. Disease modeling in genetic kidney diseases: mice. Cell Tissue Res 2017; 369:159-170. [PMID: 28601904 DOI: 10.1007/s00441-017-2639-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/04/2017] [Indexed: 12/27/2022]
Abstract
The mouse still represents arguably the most important mammal organism in research for modeling human genetic kidney diseases in vivo. Compared with many other mammal species, the breeding and maintenance of mice in the laboratory is relatively simple and cheap and reproduction cycles are short. In addition to classic gene knockout mouse lines, new molecular biological technologies have led to the development of a plethora of other, more sophisticated, mouse models, allowing the targeting of genes or gene function in a cell-specific, tissue-specific and time-dependent fashion. With the refinement of more recently developed genome-editing technologies, including the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system and other engineered nucleases such as zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), our "tool set" of mouse models is expected to rapidly expand. These technological advances hold great promise and should enable us to study and hence understand the biology of inherited kidney diseases in greater detail. By analogy, we may be able to answer questions regarding the impact of individual proteins on the development of human kidney disorders, the underlying mechanisms governing the evolution of the disease and the predicted responsiveness to therapeutic interventions. Moreover, knockout and transgenic mouse models can be highly informative with respect to the effects of genetic variations on renal phenotypes. This review focuses on mouse models that have been devised primarily to study monogenic human kidney diseases, which are typically caused by a single abnormal gene and passed on in a Mendelian pattern. Despite the large number of human hereditary kidney disorders and the multitude of mouse models described in the literature, we attempt to give a balanced overview of several well-known renal pathologies, a few of which are addressed in some detail.
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Affiliation(s)
- Andreas F Hofmeister
- Department of Internal Medicine and Nephrology, University Hospital Giessen and Marburg, Philipps-University Marburg, Baldingerstrasse 1, 35033, Marburg, Germany
| | - Martin Kömhoff
- University Children's Hospital, Philipps-University Marburg, Marburg, Germany
| | - Stefanie Weber
- University Children's Hospital, Philipps-University Marburg, Marburg, Germany
| | - Ivica Grgic
- Department of Internal Medicine and Nephrology, University Hospital Giessen and Marburg, Philipps-University Marburg, Baldingerstrasse 1, 35033, Marburg, Germany.
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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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249
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Ito Y, Katayama K, Nishibori Y, Akimoto Y, Kudo A, Kurayama R, Hada I, Takahashi S, Kimura T, Fukutomi T, Katada T, Suehiro J, Beltcheva O, Tryggvason K, Yan K. Wolf-Hirschhorn syndrome candidate 1-like 1 epigenetically regulates nephrin gene expression. Am J Physiol Renal Physiol 2017; 312:F1184-F1199. [PMID: 28228401 DOI: 10.1152/ajprenal.00305.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 02/09/2017] [Accepted: 02/21/2017] [Indexed: 01/13/2023] Open
Abstract
Altered expression of nephrin underlies the pathophysiology of proteinuria in both congenital and acquired nephrotic syndrome. However, the epigenetic mechanisms of nephrin gene regulation remain elusive. Here, we show that Wolf-Hirschhorn syndrome candidate 1-like 1 long form (WHSC1L1-L) is a novel epigenetic modifier of nephrin gene regulation. WHSC1L1-L was associated with histone H3K4 and H3K36 in human embryonic kidney cells. WHSC1L1-L gene was expressed in the podocytes, and functional protein product was detected in these cells. WHSC1L1-L was found to bind nephrin but not other podocyte-specific gene promoters, leading to its inhibition/suppression, abrogating the stimulatory effect of WT1 and NF-κB. Gene knockdown of WHSC1L1-L in primary cultured podocytes accelerated the transcription of nephrin but not CD2AP. An in vivo zebrafish study involving the injection of Whsc1l1 mRNA into embryos demonstrated an apparent reduction of nephrin mRNA but not podocin and CD2AP mRNA. Immunohistochemistry showed that both WHSC1L1-L and nephrin emerged at the S-shaped body stage in glomeruli. Immunofluorescence and confocal microscopy displayed WHSC1L1 to colocalize with trimethylated H3K4 in the glomerular podocytes. Chromatin immunoprecipitation assay revealed the reduction of the association of trimethylated H3K4 at the nephrin promoter regions. Finally, nephrin mRNA was upregulated in the glomerulus at the early proteinuric stage of mouse nephrosis, which was associated with the reduction of WHSC1L1. In conclusion, our results demonstrate that WHSC1L1-L acts as a histone methyltransferase in podocytes and regulates nephrin gene expression, which may in turn contribute to the integrity of the slit diaphragm of the glomerular filtration barrier.
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Affiliation(s)
- Yugo Ito
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Kan Katayama
- Department of Medical Biochemistry and Biophysics, Division of Matrix Biology, Karolinska Institute, Stockholm, Sweden
| | - Yukino Nishibori
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Yoshihiro Akimoto
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Akihiko Kudo
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Ryota Kurayama
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Ichiro Hada
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Shohei Takahashi
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Toru Kimura
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan; and
| | - Toshiyuki Fukutomi
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan; and
| | - Tomohisa Katada
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan; and
| | - Junichi Suehiro
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan; and
| | - Olga Beltcheva
- Molecular Medicine Center and Department of Medical Chemistry and Biochemistry, Medical University of Sofia, Sofia, Bulgaria
| | - Karl Tryggvason
- Department of Medical Biochemistry and Biophysics, Division of Matrix Biology, Karolinska Institute, Stockholm, Sweden
| | - Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan;
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250
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Boyer O, Dorval G, Servais A. Hereditary Podocytopathies in Adults: The Next Generation. KIDNEY DISEASES 2017; 3:50-56. [PMID: 28868292 DOI: 10.1159/000477243] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 04/28/2017] [Indexed: 01/15/2023]
Abstract
Idiopathic nephrotic syndrome may have two underlying mechanisms: either (1) an alteration of the immune system resulting in the production of a putative circulating factor of glomerular permeability; or (2) mutations in the structural genes of the glomerular filtration barrier in which case patients are typically multidrug resistant and do not recur after transplantation. The latter forms have been recently recognized as "hereditary podocytopathies." In the past few years, positional cloning approaches that allow the identification of gene mutations underlying diseases whose pathophysiology is unknown and animal models have helped decipher the pathophysiological mechanisms of the glomerular filtration process. Recently, the advent of next-generation sequencing (NGS) techniques has greatly facilitated the identification of numerous novel causative genes in hereditary podocytopathies. Moreover, it has revealed mutations in unexpected genes and has widened the phenotypes associated with podocyte gene mutations. The list of genes mutated in hereditary podocytopathies is constantly evolving and consists to date of more than 40 genes. However, the most recently identified genes are extremely rarely mutated and may concern only a couple of families worldwide. These discoveries provided crucial insight into the pathophysiological mechanisms linking podocyte proteins to kidney function. This review will focus on monogenic podocytopathies affecting adult patients.
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Affiliation(s)
- Olivia Boyer
- Néphrologie pédiatrique, Centre de référence MARHEA, Hôpital Necker - Enfants Malades, APHP, Paris, France.,Inserm U1163, Institut Imagine, Université Paris-Descartes Sorbonne Paris Cité, Paris, France
| | - Guillaume Dorval
- Néphrologie pédiatrique, Centre de référence MARHEA, Hôpital Necker - Enfants Malades, APHP, Paris, France.,Inserm U1163, Institut Imagine, Université Paris-Descartes Sorbonne Paris Cité, Paris, France
| | - Aude Servais
- Néphrologie, Centre de référence MARHEA, Hôpital Necker - Enfants Malades, APHP, Paris, France.,Inserm U1163, Institut Imagine, Université Paris-Descartes Sorbonne Paris Cité, Paris, France
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