RESUMEN
Background and Aims: Although activation of hepatic stellate cells (HSCs) plays a central role in the development of liver fibrosis, the mechanism underlying the activation of HSCs remains unclear. Keratin 17 (KRT17), a member of the intermediate filament family, can regulate tumor cell proliferation and migration. The current study aimed to elucidate the role of KRT17 in the activation of HSCs and the mechanisms underlying liver fibrosis. Methods: The expression of KRT17 was determined using immunohistochemistry in tissue microarray. Western blotting and qRT-PCR assays were used to determine the KRT17 expression in fibrotic liver tissues obtained from human subjects and mice. LX-2 cells were treated with TGF-ß1 recombinant protein and adipocyte differentiation mixture (MDI) mix to induce and reverse LX-2 cell activation, respectively, in order to explore the correlation between KRT17 and HSC activation. Additionally, cell proliferation and migration abilities of LX-2 cells transfected with KRT17-overexpressing plasmid or small interfering RNA were determined using CCK-8, flow cytometry, Transwell, and wound healing assays. Finally, rescue assay was used to explore the role of KRT17 in HSC activation and epithelial-mesenchymal transition (EMT). Results: The expression of KRT17 was higher in the human and mouse fibrotic liver tissues than in healthy liver tissues, and it was positively correlated with HSC activation. Upregulated KRT17 enhanced proliferation, migration, HSC activation and EMT in LX-2 cells, while knockdown of KRT17 reversed these effects. TGF-ß1 recombinant protein accelerated KRT17-mediated EMT, HSC activation and proliferation, while TGF-ß1 inhibitor counteracted the effect of KRT17 in vitro. Conclusions: KRT17 promoted HSC activation, proliferation and EMT in hepatic fibrosis probably via TGF-ß1 signaling, and KRT17 might serve as a therapeutic target for the treatment of liver fibrosis.
RESUMEN
OBJECTIVE: To study the effects of decreased leptin expression on liver fibrosis. METHODS: The small interfering RNA, targeting leptin gene, was designed according to the secondary structure of leptin gene. The recombinant plasmids were encapsulated with lipofectamine and then injected into carbon tetrachloride (CCl4) induced rat liver fibrosis models. Leptin and I, III collage were detected by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The mRNA and protein levels of leptin in the fibrotic liver transfected with leptin shRNA were significantly decreased compared with those in controls (P less than 0.01). The depositions of type I and type III collagens were also decreased (P less than 0.01). CONCLUSION: Decreased leptin expression prevents liver fibrosis.
