title: Negative regulation of Smad1 pathway and collagen IV expression by store-operated Ca2+entry in glomerular mesangial cells.
abstract: Collagen IV (Col IV) is a major component of expanded glomerular extracellular matrix in diabetic nephropathy and Smad1 is a key molecule regulating Col IV expression in mesangial cells (MCs). The present study was conducted to determine if Smad1 pathway and Col IV protein abundance were regulated by store-operated Ca2+entry (SOCE). In cultured human MCs, pharmacological inhibition of SOCE significantly increased the total amount of Smad1 protein. Activation of SOCE blunted high-glucose-increased Smad1 protein content. Treatment of human MCs with ANG II at 1 µM for 15 min, high glucose for 3 days, or TGF-β1 at 5 ng/ml for 30 min increased the level of phosphorylated Smad1. However, the phosphorylation of Smad1 by those stimuli was significantly attenuated by activation of SOCE. Knocking down Smad1 reduced, but expressing Smad1 increased, the amount of Col IV protein. Furthermore, activation of SOCE significantly attenuated high-glucose-induced Col IV protein production, and blockade of SOCE substantially increased the abundance of Col IV. To further verify those in vitro findings, we downregulated SOCE specifically in MCs in mice using small-interfering RNA (siRNA) against Orai1 (the channel protein mediating SOCE) delivered by the targeted nanoparticle delivery system. Immunohistochemical examinations showed that expression of both Smad1 and Col IV proteins was significantly greater in the glomeruli with positively transfected Orai1 siRNA compared with the glomeruli from the mice without Orai1 siRNA treatment. Taken together, our results indicate that SOCE negatively regulates the Smad1 signaling pathway and inhibits Col IV protein production in MCs.
authors.affiliation: Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas.|Department of Endocrinology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, Peoples Republic of China.
authors.forename: Peiwen
authors.initials: P
authors.lastname: Wu
authors.affiliation: Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas.|Department of Endocrinology, The Second Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, Zhejiang, China.
authors.forename: Yuezhong
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas.|Department of Clinical Medicine, Wannan Medical College, Wuhu, China.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas.|The First Affiliated Hospital to Anhui University of Traditional Chinese Medicine, Hefei, China; and.
authors.forename: Hui
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas.
authors.forename: Sarika
authors.initials: S
authors.lastname: Chaudhari
authors.affiliation: Chemical Engineering, California Institute of Technology, Pasadena, California.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Davis
authors.affiliation: Chemical Engineering, California Institute of Technology, Pasadena, California.
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Zuckerman
authors.affiliation: Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas; rong.ma@unthsc.edu.
authors.forename: Rong
authors.initials: R
authors.lastname: Ma
mesh_terms: D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects; D002478:Cells, Cultured; D024141:Collagen Type IV / Q000378:metabolism*; D005786:Gene Expression Regulation; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D050527:Mesangial Cells / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D000071740:ORAI1 Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D034622:RNA Interference; D051898:Smad1 Protein / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014162:Transfection; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology
chemical_list: D002121:Calcium Channel Blockers; D024141:Collagen Type IV; D000071740:ORAI1 Protein; C520430:Orai1 protein, mouse; C497399:SMAD1 protein, human; D051898:Smad1 Protein; C497401:Smad1 protein, mouse; C508960:TGFB1 protein, human; D053773:Transforming Growth Factor beta1; D000804:Angiotensin II; D005947:Glucose
keywords: extracellular matrix; store-operated calcium entry