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Epithelial-to-mesenchymal transition (EMT) has been implicated in embryonic development and various pathological events. However, the involvement of microRNA in the process of EMT remains to be fully defined in hepatocyte. ZEB1 is a well-known transcriptional repressor of E-cadherin and plays a major role in triggering EMT during organ fibrosis and cancer cell metastasis. Computational microRNA target predictions detect a conserved sequence matching to miR-101 in the 3′UTR of ZEB1 mRNA. Our results confirm that miR-101 suppresses ZEB1 expression by targeting the predicted site of ZEB1 3′UTR. Subsequent investigations show that miR-101 is significantly downregulated in the cultured hepatocytes undergoing EMT and in the hepatocytes isolated from fibrotic liver. Along with the loss of miR-101, the ZEB1 expression increases simultaneously in hepatocytes. In addition, miR-101 levels in HCC cell lines are negatively associated with the ZEB1 productions and the metastatic potentials of tumor cells. Mechanistically, we demonstrate that miR-101 significantly inhibits the TGF-β1-induced EMT in hepatocytes, whereas inhibition of miR-101 promotes the EMT process as indicated by the changes of morphology, cell migration, and the expression profiles of EMT markers. In the fibrotic liver, ectopic expression of miR-101 can significantly downregulate ZEB1 in the hepatocyte and thereby reduces the mesenchymal marker expression. Moreover, miR-101 significantly inhibits the proliferation and migration of HCC cell. Our results demonstrate that miR-101 regulates HCC cell phenotype by upregulating the epithelial marker genes and suppressing the mesenchymal ones. J. Cell. Physiol. 9999: 2706-2717, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Aberrant N-glycosylation caused by altered N-acetyl glucosaminyltransferase V (GnT-V) expression is known to regulate tumor invasion and metastasis by modulating multiple cytokine signaling pathways. However, the exact role of GnT-V in the development of liver fibrosis has not been clearly defined. Here, we induced mouse liver fibrosis by ip injections of carbon tetrachloride (CCl4) or thioacetamide (TAA) and observed significant increase of hepatic GnT-V during the processes of liver fibrogenesis. Meanwhile, upregulations of GnT-V were detected in the activated hepatic stellate cells (HSCs) and injured hepatocytes. To knock down hepatic GnT-V expression, adenovirus that expressed the GnT-V siRNA was injected via the tail vein. Adenovirus-mediated delivery of GnT-V siRNA dramatically reduced the GnT-V expression in fibrotic liver and activated HSC in vivo and consequently alleviated CCl4- or TAA-induced liver fibrosis as assessed through collagen deposition and profiles of profibrogenic markers. Furthermore, knockdown of GnT-V in HSCs reduced transforming growth factor beta (TGF-β)/Smad signaling and blunted the activated HSC phenotype. The suppression of TGF-β/Smad signaling in HSCs correlated with the decrease of GnT-V-modified β1,6-branched N-glycan on TGF-β receptors. Knockdown of GnT-V also suppressed platelet-derived growth factor (PDGF)–induced HSC proliferation and migration through inhibiting PDGF/Erk signaling. Finally, we demonstrated that knockdown of GnT-V profoundly suppressed TGF-β1-induced epithelial-mesenchymal transition (EMT) in hepatocytes by morphological assessment and reversal of EMT markers. In conclusion, this study demonstrates that GnT-V is implicated in hepatotoxin-induced liver fibrosis, and targeting GnT-V may be a feasible and promising approach for treating liver fibrosis. [ABSTRACT FROM PUBLISHER]

Abstract: Epithelial-to-mesenchymal transition (EMT) has been implicated in embryonic development and various pathological events. Snail1 is a well-known E-cadherin-transcriptional repressor that is significantly upregulated during the TGF-β1-induced EMT in hepatocyte. However, the functional involvement of microRNA during the EMT process in hepatocyte remains to be determined. Here, we revealed that while the expression of Snail1 increased during the TGF-β1-induced EMT in AML12 murine hepatocytes, the expression of miR-30 family members exhibited significant downregulation. Computational microRNA target predictions detected a conserved sequence matching to the seed region of miR-30 in the 3′UTR of Snail1 mRNA. Our results demonstrated that miR-30 could negatively regulate the expression of Snail1 by direct targeting the predicted binding site. More importantly, transfection of miR-30b mimics significantly inhibited the TGF-β1-induced EMT in AML12 cells as assessed through cell morphology changes and the expression profiles of Snail1, E-cadherin and other fibroblast markers. Finally, we demonstrated that TGF-β1-induced hepatocyte migration was greatly suppressed in cells transfected with miR-30b mimics. Our results provide a new insight into the role of miR-30 in regulating EMT, which could be of importance in understanding the related physiologic and pathologic processes. [Copyright &y& Elsevier]