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Janus Kinase 2/Signal Transducer And Activator Of Transcription 3 Inhibitors Attenuate The Effect Of Cardiotrophin-Like Cytokine Factor 1 And Human Focal Segmental Glomerulosclerosis Serum On Glomerular Filtration Barrier., Mukut Sharma, Jianping Zhou, Jean-François Gauchat, Ram Sharma, Ellen T. Mccarthy, Tarak Srivastava, Virginia J. Savin

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Recurrence of idiopathic focal segmental glomerulosclerosis (FSGS) after renal transplantation is believed to be caused by a circulating factor(s). We detected cardiotrophin-like cytokine factor 1 (CLCF1), a member of the interleukin 6 family, in the plasma from patients with recurrent FSGS. We hypothesized that CLCF1 contributes to the effect of FSGS serum on the glomerular filtration barrier in vitro. Presently, we studied the effect of CLCF1 on isolated rat glomeruli using an in vitro assay of albumin permeability (P(alb)). CLCF1 (0.05-100 ng/mL) increased P(alb) and caused maximal effect at 5-10 ng/mL (P < 0.001). The increase in Palb was analogous to the effect of FSGS serum. Anti-CLCF1 monoclonal antibody blocked the CLCF1-induced increase in P(alb) and significantly attenuated the effect of FSGS serum (P < 0.001). The heterodimer composed of CLCF1 and cosecreted molecule cytokine receptor-like factor 1 (CRLF1) attenuated the increase in P(alb) caused by CLCF1 or FSGS serum. Western blot analysis showed that CLCF1 upregulated phosphorylation of signal transducer and activator of transcription 3 (STAT3) (Tyr705) in glomeruli. This effect was diminished by the heterodimer CLCF1-CRLF1. Janus kinase 2 (JAK2) inhibitor BMS-1119543 or STAT3 inhibitor Stattic significantly blocked the effect of CLCF1 or FSGS serum on P(alb) (P < 0.001). These novel findings suggest that when monomeric CLCF1 increases P(alb), the heterodimer CLCF1-CRLF1 may protect the glomerular filtration barrier. We speculate that albuminuria in FSGS is related to qualitative or quantitative changes in the CLCF1-CRLF1 complex, and that JAK2 or STAT3 inhibitors may be novel therapeutic agents to treat FSGS.

Efficacy Of Galactose And Adalimumab In Patients With Resistant Focal Segmental Glomerulosclerosis: Report Of The Font Clinical Trial Group., Howard Trachtman, Suzanne Vento, Emily Herreshoff, Milena Radeva, Jennifer Gassman, Daniel T. Stein, Virginia J. Savin, Mukut Sharma, Jochen Reiser, Changli Wei, Michael Somers, Tarak Srivastava, Debbie S. Gipson

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BACKGROUND: Patients with resistant focal segmental glomerulosclerosis (FSGS) who are unresponsive to corticosteroids and other immunosuppressive agents are at very high risk of progression to end stage kidney disease. In the absence of curative treatment, current therapy centers on renoprotective interventions that reduce proteinuria and fibrosis. The FONT (Novel Therapies for Resistant FSGS) Phase II clinical trial (NCT00814255, Registration date December 22, 2008) was designed to assess the efficacy of adalimumab and galactose compared to standard medical therapy which was comprised of lisinopril, losartan, and atorvastatin.

METHODS: Key eligibility criteria were biopsy confirmed primary FSGS or documentation of a causative …

Hla-Dqa1 And Plcg2 Are Candidate Risk Loci For Childhood-Onset Steroid-Sensitive Nephrotic Syndrome., Rasheed A. Gbadegesin, Adebowale Adeyemo, Nicholas J A Webb, Larry A A. Greenbaum, Asiri Abeyagunawardena, Shenal Thalgahagoda, Arundhati Kale, Debbie Gipson, Tarak Srivastava, Jen-Jar Lin, Deepa Chand, Tracy E. Hunley, Patrick D. Brophy, Arvind Bagga, Aditi Sinha, Michelle N. Rheault, Joanna Ghali, Kathy Nicholls, Elizabeth Abraham, Halima S. Janjua, Abiodun Omoloja, Gina-Marie Barletta, Yi Cai, David D. Milford, Catherine O'Brien, Atif Awan, Vladimir Belostotsky, William E. Smoyer, Alison Homstad, Gentzon Hall, Guanghong Wu, Shashi Nagaraj, Delbert Wigfall, John Foreman, Michelle P. Winn, Mid-West Pediatric Nephrology Consortium

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Steroid-sensitive nephrotic syndrome (SSNS) accounts for >80% of cases of nephrotic syndrome in childhood. However, the etiology and pathogenesis of SSNS remain obscure. Hypothesizing that coding variation may underlie SSNS risk, we conducted an exome array association study of SSNS. We enrolled a discovery set of 363 persons (214 South Asian children with SSNS and 149 controls) and genotyped them using the Illumina HumanExome Beadchip. Four common single nucleotide polymorphisms (SNPs) in HLA-DQA1 and HLA-DQB1 (rs1129740, rs9273349, rs1071630, and rs1140343) were significantly associated with SSNS at or near the Bonferroni-adjusted P value for the number of single variants that were …

Ethanol At Low Concentrations Protects Glomerular Podocytes Through Alcohol Dehydrogenase And 20-Hete., Ellen T. Mccarthy, Jianping Zhou, Ryan Eckert, David Genochio, Rishi Sharma, Olurinde Oni, Alok De, Tarak Srivastava, Ram Sharma, Virginia J. Savin, Mukut Sharma

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Clinical studies suggest cardiovascular and renal benefits of ingesting small amounts of ethanol. Effects of ethanol, role of alcohol dehydrogenase (ADH) or of 20-hydroxyeicosatetraenoic acid (20-HETE) in podocytes of the glomerular filtration barrier have not been reported. We found that mouse podocytes at baseline generate 20-HETE and express ADH but not CYP2e1. Ethanol at high concentrations altered the actin cytoskeleton, induced CYP2e1, increased superoxide production and inhibited ADH gene expression. Ethanol at low concentrations upregulated the expression of ADH and CYP4a12a. 20-HETE, an arachidonic acid metabolite generated by CYP4a12a, blocked the ethanol-induced cytoskeletal derangement and superoxide generation. Ethanol at high …

Renal And Hematological Effects Of Clcf-1, A B-Cell-Stimulating Cytokine Of The Il-6 Family., Virginia J. Savin, Mukut Sharma, Jianping Zhou, David Gennochi, Timothy Fields, Ram Sharma, Ellen T. Mccarthy, Tarak Srivastava, Jos Domen, Aurélie Tormo, Jean-François Gauchat

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CLCF-1 is a cytokine known for B-cell stimulation and for neurotrophic properties. We have identified CLCF-1 as a potential injurious factor in the human renal disease focal segmental glomerulosclerosis (FSGS). We investigated its effects on renal cells and renal function in in vitro and in vivo studies. Methods include measurement of the effect of CLCF-1 on phosphorylation of target molecules of the JAK/STAT pathway, on cytoskeleton and cell morphology in cultured podocytes, on albumin permeability of isolated rat glomeruli, and on tissue phosphorylation and urine albumin after acute or chronic CLCF-1 injection. In addition, cell sorting was performed to determine …