title: TRPM7 channel regulates PDGF-BB-induced proliferation of hepatic stellate cells via PI3K and ERK pathways.
abstract: TRPM7, a non-selective cation channel of the TRP channel superfamily, is implicated in diverse physiological and pathological processes including cell proliferation. Recently, TRPM7 has been reported in hepatic stellate cells (HSCs). Here, we investigated the contribution role of TRPM7 in activated HSC-T6 cell (a rat hepatic stellate cell line) proliferation. TRPM7 mRNA and protein were measured by RT-PCR and Western blot in rat model of liver fibrosis in vivo and PDGF-BB-activated HSC-T6 cells in vitro. Both mRNA and protein of TRPM7 were dramatically increased in CCl4-treated rat livers. Stimulation of HSC-T6 cells with PDGF-BB resulted in a time-dependent increase of TRPM7 mRNA and protein. However, PDGF-BB-induced HSC-T6 cell proliferation was inhibited by non-specific TRPM7 blocker 2-aminoethoxydiphenyl borate (2-APB) or synthetic siRNA targeting TRPM7, and this was accompanied by downregulation of cell cycle proteins, cyclin D1, PCNA and CDK4. Blockade of TRPM7 channels also attenuated PDGF-BB induced expression of myofibroblast markers as measured by the induction of α-SMA and Col1α1. Furthermore, the phosphorylation of ERK and AKT, associated with cell proliferation, decreased in TRPM7 deficient HSC-T6 cells. These observations suggested that TRPM7 channels contribute to perpetuated fibroblast activation and proliferation of PDGF-BB induced HSC-T6 cells via the activation of ERK and PI3K pathways. Therefore, TRPM7 may constitute a useful target for the treatment of liver fibrosis.
authors: School of Pharmacy, Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032, China; Institute for Liver Diseases of Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032, China. Electronic address: fangling_1984@126.com.
authors: Ling
authors: L
authors: Fang
authors: Shuxiang
authors: S
authors: Zhan
authors: Cheng
authors: C
authors: Huang
authors: Xi
authors: X
authors: Cheng
authors: Xiongwen
authors: X
authors: Lv
authors: Hongfang
authors: H
authors: Si
authors: Jun
authors: J
authors: Li
mesh_terms: D000818:Animals; D000077214:Becaplermin; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D000090602:Collagen Type I, alpha 1 Chain; D005347:Fibroblasts / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D055166:Hepatic Stellate Cells / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D008103:Liver Cirrhosis / Q000378:metabolism / Q000473:pathology; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D008297:Male; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D020574:Proto-Oncogene Proteins c-sis / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D050053:TRPM Cation Channels / Q000502:physiology*
chemical_list: D000077214:Becaplermin; D000090602:Collagen Type I, alpha 1 Chain; D019869:Phosphatidylinositol 3-Kinases; D020574:Proto-Oncogene Proteins c-sis; D050053:TRPM Cation Channels; C000716129:Col1a1 protein, rat; C486584:Trpm7 protein, rat
keywords: 2-APB; 2-aminoethoxydiphenyl borate; AKT; CDK4; Col1a1; ECM; ERK; HSC; Liver fibrosis; P70 ribosomal protein S6 kinase; P70S6K; PCNA; PDGF; PI3K; TRPM7; collagen type 1 alpha 1; cyclin-dependent kinase 4; extracellular matrix; extracellular signal-regulated kinase; hepatic stellate cell; phosphoinositide 3-kinase; platelet-derived growth factor; proliferating cell nuclear antigen; protein kinase B; short interfering RNA; siRNA; transient receptor potential melastatin 7; α-SMA; α-smooth muscle actin