title: miR-378reduces mesangial hypertrophy and kidney tubular fibrosis via MAPK signalling.
abstract: The regulatory role of a novel miRNA,miR-378, was determined in the development of fibrosis through repression of the MAPK1 pathway,miR-378and fibrotic gene expression was examined in streptozotocin (STZ)-induced diabetic mice at 18 weeks or in unilateral ureteral obstruction (UUO) mice at 7 days.miR-378transfection of proximal tubular epithelial cells, NRK52E and mesangial cells was assessed with/without endogenousmiR-378knockdown using the locked nucleic acid (LNA) inhibitor. NRK52E cells were co-transfected with the mothers against decapentaplegic homolog 3 (SMAD3) CAGA reporter andmiR-378in the presence of transforming growth factor-β (TGF-β1) was assessed. Quantitative polymerase chain reaction (qPCR) showed a significant reduction inmiR-378(P<0.05) corresponding with up-regulated type I collagen, type IV collagen and α-smooth muscle actin (SMA) in kidneys of STZ or UUO mice, compared with controls. TGF-β1 significantly increased mRNA expression of type I collagen (P<0.05), type IV collagen (P<0.05) and α-SMA (P<0.05) in NRK52E cells, which was significantly reduced (P<0.05) followingmiR-378transfection and reversed following addition of the LNA inhibitor of endogenousmiR-378Overexpression ofmiR-378inhibited mesangial cell expansion and proliferation in response to TGF-β1, with LNA-miR-378transfection reversing this protective effect, associated with cell morphological alterations. The protective function of MAPK1 onmiR-378was shown in kidney cells treated with the MAPK1 inhibitor, selumetinib, which inhibited mesangial cell hypertrophy in response to TGF-β1. Taken together, these results suggest thatmiR-378acts via regulation of the MAPK1 pathway. These studies demonstrate the protective function of MAPK1, regulated bymiR-378, in the induction of kidney cell fibrosis and mesangial hypertrophy.
authors.affiliation: Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton.
authors.forename: Kevin
authors.initials: K
authors.lastname: Yao
authors.affiliation: Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton.
authors.forename: Andrea F
authors.initials: AF
authors.lastname: Wise
authors.affiliation: Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton.
authors.forename: Ricky
authors.initials: R
authors.lastname: Lau
authors.affiliation: Department of Materials Engineering, Monash University, Clayton.
authors.forename: Hsin-Hui
authors.initials: HH
authors.lastname: Shen
authors.affiliation: Department of Nephrology and Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria, Australia.
authors.forename: Greg H
authors.initials: GH
authors.lastname: Tesch
authors.affiliation: Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton sharon.ricardo@monash.edu).
authors.forename: Sharon D
authors.initials: SD
authors.lastname: Ricardo
mesh_terms: D000818:Animals; D001562:Benzimidazoles; D002478:Cells, Cultured; D003928:Diabetic Nephropathies / Q000378:metabolism* / Q000473:pathology; D005355:Fibrosis; D006801:Humans; D006984:Hypertrophy; D007668:Kidney / Q000473:pathology*; D020935:MAP Kinase Signaling System; D008297:Male; D050527:Mesangial Cells / Q000473:pathology*; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000378:metabolism*; D051381:Rats; D053773:Transforming Growth Factor beta1
chemical_list: C517975:AZD 6244; D001562:Benzimidazoles; C546119:MIRN378 microRNA, mouse; D035683:MicroRNAs; D053773:Transforming Growth Factor beta1
keywords: diabetic nephropathy; kidney fibrosis; mesangial cells; microRNA (miRNA); transforming growth factor-β (TGF-β1)