Regulation of hepatic stellate cell activation and proliferation by Hedgehog signal pathway

Abstract

Objective To study the expression of Hedgehog signal pathway in rat hepatic stellate cell (HSC) line rHSC-99. The method of RNAi was adopted to inhibit Hedgehog signal pathway,and estimate the regulation role of Hedgehog signal pathway in activation and proliferation of HSC. Methods RTPCR was used to detect the expression of Hedgehog signal pathway in rat HSC line rHSC-99. Transcripts of siRNA sequence of the genes Ihh,Smo,and Gli2 were designed,and transfected into HSC respectively. Then the expression of these mRNAs were detected by SYBR green flurogenic quantitative PCR. The expression of α-SMA was detected by Western blot. The variation of type I collagen in culture supernatant of HSC was detected by ELISA. The proliferation of HSC was measured by MTT assay. Results HSC expressed mRNAs of Ihh,Smo,Ptc,Gli2,Gli3. The expression of these mRNAs could be reduced by trans-fecting plasmids encoded siRNA of Ihh,Smo or Gli2 (0. 254 ±0.130,0.221 ±0. 150,0. 235 ±0. 110 vs 1 ,P<0.01). Transfection experiment demonstrated the reduction of the expression of α-SMA (0. 191 ± 0.014,0. 357 ± 0. 021,0. 086 ± 0. 016 vs 1. 143 ± 0. 017, P<0. 01) and secretion of collagen I (22.9±2.0,16.4±1.4,17.6±1.8 vs 40.7 ±4.3,P<0.01) in HSC,and HSC proliferation was decreased (0.204 ±0.019,0. 226 ±0. 014,0. 228 ±0.015 vs 0. 412 ±0. 016,P<0.05). Conclusion This study showed the expression of Hedgehog signal pathway in HSC. Down-regulation of Hedgehog signal pathway may inhibit HSC activation and proliferation. Key words: Hepatic stellate cell; Signal pathway; Proliferation