title: Spironolactone inhibits apoptosis in rat mesangial cells under hyperglycaemic conditions via the Wnt signalling pathway.
abstract: Mesangial cells (MCs) play a crucial role in maintaining structure and function of glomerular tufts, providing structural support for capillary loops and modulating glomerular filtration by their contractility. MCs apoptosis occurs in experimental diabetic nephropathy, and this correlates with worsening albuminuria. Accumulating evidence suggests that mineralocorticoid receptor (MR) blockade effectively reduces proteinuria in diabetic nephropathy; however, it is rarely known whether spironolactone (SPI), a nonspecific MR antagonist, inhibits apoptosis in MCs under hyperglycaemic conditions. The objectives of this study are to determine the relationship between SPI and apoptosis, and investigate the cell signalling pathway by which SPI inhibits apoptosis. Rat MCs were treated with 30 mM D-glucose and 10(-8), 10(-7) or 10(-6) M aldosterone (ALD) for 24 h. In some experiments, MCs were pretreated with 10(-7) M SPI or 10 mM LiCl for 1 h. Apoptosis was evaluated by cell nucleus staining and flow cytometric analyses, and caspase-3 activity was assayed. Gene and protein expression were quantified using quantitative real-time PCR and Western blotting, respectively. SPI directly inhibited high glucose and ALD-induced MCs apoptosis in a caspase-dependent manner. Importantly, SPI inhibited MCs apoptosis via the Wnt signalling pathway. SPI promoted activation of the Wnt signalling pathway in MCs, leading to upregulation of Wnt4 and Wnt5a mRNA expression, decreased GSK-3β protein expression and increased β-catenin protein expression. As a conclusion, this study suggests that SPI may inhibit apoptosis in MCs during hyperglycaemic conditions via the Wnt signalling pathway. Blockade of the ALD system may represent a novel therapeutic strategy to prevent MCs injury under hyperglycaemic conditions.
authors.affiliation: Department of Nephrology, The First Affiliated Hospital of Harbin Medical University, Heilongjiang 150001, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhu
authors.forename: Hongwei
authors.initials: H
authors.lastname: Yu
authors.forename: Hongjiang
authors.initials: H
authors.lastname: He
authors.forename: Jiuli
authors.initials: J
authors.lastname: Ding
authors.forename: Jie
authors.initials: J
authors.lastname: Tang
authors.forename: Dan
authors.initials: D
authors.lastname: Cao
authors.forename: Lirong
authors.initials: L
authors.lastname: Hao
mesh_terms: D000450:Aldosterone / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D018021:Lithium Chloride / Q000494:pharmacology; D050527:Mesangial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000451:Mineralocorticoid Receptor Antagonists / Q000494:pharmacology; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013148:Spironolactone / Q000494:pharmacology*; D051153:Wnt Proteins / Q000235:genetics; D060449:Wnt Signaling Pathway / Q000187:drug effects* / Q000235:genetics; D000071818:Wnt-5a Protein; D060528:Wnt4 Protein / Q000235:genetics; D051176:beta Catenin / Q000378:metabolism
chemical_list: D000451:Mineralocorticoid Receptor Antagonists; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; D060528:Wnt4 Protein; C555583:Wnt4 protein, rat; C491837:Wnt5a protein, rat; D051176:beta Catenin; D013148:Spironolactone; D000450:Aldosterone; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3; D053148:Caspase 3; D018021:Lithium Chloride; D005947:Glucose