Journal Article

MicroRNA-221/222 upregulation indicates the activation of stellate cells and the progression of liver fibrosis

Yoshizato, Katsutoshi, Enomoto, Masaru, Sekiya, Yumiko, Kawada, Norifumi, Ogawa, Tomohiro, Fujii, Hideki, Ikeda, Kazuo

2012

Overview

Background MicroRNAs (miRNAs) are important in hepatic pathophysiology and the development of liver cancer. Objective To explore miRNAs that are regulated with the progression of liver fibrosis caused by chronic liver disease. Design The regulated miRNAs in human livers infected with hepatitis C virus were identified by microarray analysis. Their expression in human livers with non-alcoholic steatohepatitis, mouse livers from two fibrosis models and cultured stellate cells was validated by real-time RT-PCR. The regulation of miR-222 expression in stellate cells by nuclear factor kappa B (NF-κB) was assayed. Finally, the effects of an miR-222 precursor or inhibitor on the expression of cyclin-dependent kinase inhibitor 1B (CDKN1B) and the growth of LX-2 cells were determined. Results It was found that miR-199a-5p/199a-3p and miR-221/222 were upregulated in the human liver in a fibrosis progression–dependent manner. Among these miRNAs, miR-221/222 were upregulated in LX-2 cells and increased during the course of culture-dependent activation of mouse primary stellate cells, in a manner similar to the expression of α1(I) collagen and α-smooth muscle actin mRNAs. The expression of miR-221/222 increased in mouse models of liver fibrosis. In contrast, an NF-κB inhibitor significantly suppressed the miR-222 induction that was stimulated in culture by transforming growth factor α or tumour necrosis factor α. Although overexpression or downregulation of miR-222 failed to regulate the growth of LX-2 cells, miR-222 bound to the CDKN1B 3′UTR and regulated the expression of the corresponding protein. Conclusion miR-221/222 may be new markers for stellate cell activation and liver fibrosis progression.

• Publisher: BMJ Publishing Group Ltd and British Society of Gastroenterology,BMJ Publishing Group,BMJ Publishing Group LTD
• Subject: 3' untranslated region / Aged / Animals / Bile / Biological and medical sciences / Biomarkers / Biopsy / Biopsy, Needle / Case-Control Studies / Cell Proliferation / Cells, Cultured / Chronic hepatitis / Clinical medicine / Collagen / cyclin-dependent kinase / Cyclin-dependent kinases / Disease Models, Animal / Disease Progression / Female / fibrosis / Gangrene / Gastroenterology. Liver. Pancreas. Abdomen / Gene Expression Regulation / Genetic Markers / Growth factors / HCV / hepatic fibrosis / hepatic stellate cell / hepatic stellate cells / Hepatic Stellate Cells - metabolism / Hepatitis / Hepatitis C virus / Humans / Immunohistochemistry / inflammation / liver / Liver cancer / Liver cirrhosis / Liver Cirrhosis - genetics / Liver Cirrhosis - metabolism / Liver Cirrhosis - pathology / Liver diseases / liver regeneration / Liver. Biliary tract. Portal circulation. Exocrine pancreas / Male / Medical sciences / Mice / Mice, Inbred C57BL / MicroRNAs - metabolism / Middle Aged / molecular biology / molecular carcinogenesis / nonalcoholic steatohepatitis / nuclear factor kappa B / Other diseases. Semiology / Random Allocation / Real-Time Polymerase Chain Reaction - methods / Rodents / Smooth muscle / Statistics, Nonparametric / Tissue Array Analysis / Tumor necrosis factor-TNF / type I collagen / Up-Regulation / α-smooth muscle actin