title: MicroRNA-19b reduces hepatic stellate cell proliferation by targeting GRB2 in hepatic fibrosis models in vivo and in vitro as part of the inhibitory effect of estradiol.
abstract: Estradiol (E2) is a major determinant of gender-based differences in the development of hepatic fibrosis. MicroRNAs (miRNAs) are endogenous 19-25 nucleotide, noncoding, single-stranded RNAs that regulate gene expression by blocking the translation or decreasing the stability of mRNAs and play an important role in liver fibrosis. The mechanisms underlying the regulation of miRNAs by E2 remain largely unknown. In this study, miR-19b levels were higher and were associated with lower GRB2 mRNA and protein levels in female rats more than in male rats. We also showed that miR-19b levels were down-regulated, were associated with the up-regulation of GRB2 mRNA and protein levels in PS (porcine serum-induced hepatic fibrosis) versus NS (normal control) groups and were up-regulated when associated with the down-regulation of GRB2 mRNA and protein levels in PS + E2 versus PS and in aHSC + E2 (estradiol treated aHSC) versus aHSC groups. MiR-19b expression inhibited cell proliferation in aHSCs, and also down-regulated GRB2 protein expression. The overexpression of miR-19b inhibited cell growth and suppressed COL1A1 protein levels by decreasing the levels of GRB2. However, the forced expression of GRB2 partly rescued the effect of miR-19b in the cells, attenuated cell proliferation, and suppressed the GRB2 protein level by up-regulating the levels of GRB2. Taken together, these findings will shed light on the role of miR-19b in regulating aHSC proliferation via the miR-19b/GRB2 axis. This newly identified miR-19b/GRB2 interaction provided novel insights into the suppressive effect of E2 on HSC proliferation and might facilitate the development of therapies targeting hepatic fibrosis.
authors: Department of Infectious Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors: Shanfei
authors: S
authors: Ge
authors: Department of Infectious Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors: Jianping
authors: J
authors: Xie
authors: Department of Infectious Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors: Fei
authors: F
authors: Liu
authors: Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
authors: Jinni
authors: J
authors: He
authors: Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
authors: Jinwen
authors: J
authors: He
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D000090602:Collagen Type I, alpha 1 Chain; D004958:Estradiol / Q000008:administration & dosage* / Q000494:pharmacology; D004967:Estrogens / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D051380:GRB2 Adaptor Protein / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D055166:Hepatic Stellate Cells / Q000166:cytology / Q000187:drug effects*; D066298:In Vitro Techniques; D008106:Liver Cirrhosis, Experimental / Q000235:genetics / Q000473:pathology*; D008297:Male; D035683:MicroRNAs / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D051381:Rats
chemical_list: D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D004967:Estrogens; D051380:GRB2 Adaptor Protein; C495950:Grb2 protein, rat; C586754:MIRN19 microRNA, rat; D035683:MicroRNAs; D004958:Estradiol
keywords: ESTRADIOL; GRB2; PROLIFERATION; miR-19b