摘要目的:探讨Hedgehog通路与肝纤维化及肝星状细胞(HSC)活化的关系.方法:清洁级SD雄性大鼠20只,均分为模型组和对照组.模型组采用腹腔注射四氯化碳(CCl4)和高脂饮食诱导肝纤维化,对照组予以正常饮食.第8周末取模型组存活大鼠与对照组中大鼠各5只处死,取左叶肝脏组织.HE、Masson染色观察两组肝组织病理变化;逆转录-多聚酶链反应(RT-PCR)检测纤维化大鼠肝脏中表达Hedgehog通路成员超音速Hedgehog信号通路(Shh)、膜受体patched(Ptc)、smoothened(Smo)和核转录因子Gli表达;实时荧光定量PCR法检测Hedgehog通路成员及HSC活化标志基因α-平滑肌肌动蛋白(α-SMA)mRNA在两组大鼠肝脏中的表达差异.体外培养HSC-T6细胞,RT-PCR检测HSC-T6细胞株中Hedgehog通路成员的表达;四甲基偶氮唑盐比色分析(MTT)法检测不同浓度环耙明(Cyclopamine,Cyc)对HSC-T6增殖的影响;分别用0、100/μmol/L的Cye干预HSC-T6,实时荧光定量PCR法检测Shh、Smo、Ptc、Gli-1及αSMA mRNA表达差异.结果:模型组大鼠肝脏有大量脂质及胶原沉积,且肝脏组织中均有Shh、Smo、Ptc、Gli-1表达.荧光定量PCR结果示模型组大鼠Shh、Smo、Gli-1及αSMA mRNA表达均较对照大鼠升高(20.45±3.31、12.78±0.53、10.88±2.41、4.91±2.59比1;P值均<0.05).Cyc在体外对HSC-T6有明显的抑制作用,且抑制作用呈剂量依赖性(F=636.81,P<0.01).荧光定量PCR结果示,用Cyc 100 μmol/L干预的HSC-T6中,Ptc、Smo、Gli-1和αSMA表达量分别为0.20±0.11、0.21±0.08、0.28±0.05和0.27±0.10,与Cyc 0μmol/L干预比较差异均有统计学意义(P值均<0.01).结论:肝纤维化过程中Hedgehog通路成员表达增高,抑制Hedgehog通路可抑制HSC活化,推测Hedgehog通路通过活化HSC促进肝纤维化的发生.

abstractsObjective To investigate the role of Hedgehog pathway in hepatic fibrosis and its association with activation of hepatic stellate cells. Methods Twenty male Spragur-Dawley rats were divided into control and model groups with 10 each. The animal models were induced by injection with CCl4 and fed with fat-rich diet. The rats in both groups were sacrified at the 8 week with 5 each and the liver tissues were removed for HSC-T6 culture. The deposition of collagen fiber in liver was detected with HE and Masson staining. RT-PCR was used to detect the expressions of Sonic hedgehog (Shh), smoothened (Smo), patched (Ptc), Gli-1 and α-smooth muscle action (α-SMA) mRNA in HSC-T6 and liver tissues. The influence of cyclopamine (Cyc) and lipopolysaccharide (LPS) on HSC-T6 proliferation were assayed by MTT. The expressions of Shh, Smo, Ptc, Gli-1 and α-SMA mRNA after intervention with Cyc (100μmol/L) and LPS were measured by real-time PCR. Results A lot of lipo and collagen deposited in liver of model rats. The Shh,Smo,Gli-1 and α-SMA mRNA were highly expressed in model rats than those in control group (2-△△Ct were 20.45±3.31 vs. 1, 12.78 ± 0. 53 vs. 1, 10.88 ± 2.41 vs. 1, 4.91 ± 2. 59 vs. 1, respectively, all P value <0. 05). In vitro Cyc inhibited HSC-T6 proliferation in dose dependant manner (F=636.81, P<0.01). Compared to the control group, the mRNA expressions of Smo, Ptc, Gli-1,α-SMA in HSC-T6 were significantly reduced after Cyc intervention (2△△Ct, were 0. 20±0. 11, 0. 21 ± 0. 08, 0. 28 ± 0. 05,0. 27±0.10,respectively, all P values<0.01). Conclusion The expression of members of Hedgehog pathway are increased in the progress of hepatic fibrosis, which may accelerate the hepatiee fibrosis by activating HSC.