粉防己碱上调Smad7表达抑制大鼠肝星状细胞活化  

Tetrandrine inhibits the activation of rat hepatic stellate cells via up-regulation of Smad 7

作　　者：陈源文[1] 李定国[1] 吴建新[1] 陈颖伟[1] 陆汉明[1] 

机构地区：[1]上海第二医科大学附属新华医院消化内科,上海200092

出　　处：《中国药理学通报》2005年第5期563-567,共5页Chinese Pharmacological Bulletin

基　　金：上海市高等学校科学技术发展基金资助项目(No02BK14)

摘　　要：目的观察低浓度粉防己碱(Tetrandrine,Tet)对培养的大鼠肝星状细胞(HSC)活化和转化生长因子β1(TGFβ1)促活化作用的影响,并探讨该作用与TGFβ1受体后信号通路的关系。方法HSC原代培养,给予Tet(0.4、0.8、1.6和3.2μmol·L-1)处理,免疫细胞化学法检测α平滑肌肌动蛋白(αSMA)表达,或给予TGFβ1(质量浓度5μg·L-1)和(或)Tet(1.6μmol·L-1)干预,分别以RTPCR和Westernblot法检测TGFβ1及其Ⅰ、Ⅱ型受体、Smad3、Smad7以及αSMAmRNA和(或)蛋白表达。结果Tet(0.4～3.2μmol·L-1)能抑制培养HSC表达αSMA。Tet(1.6μmol·L-1)抑制TGFβ1诱导的HSCαSMA表达,伴有Smad7表达上调及TGFβ1表达下降,但不影响TGFβⅠ、Ⅱ型受体和Smad3表达。结论低浓度Tet抑制培养HSC的活化和TGFβ1促活化作用,该作用与上调Smad7表达并抑制TGFβ1有关而不影响TGFβ受体表达。Aim To investigate the effect of lower concentrations of tetrandrine on culture-activation and transforming growth factor-β_1 (TGF-β_1)-stimulated activation of quiescent rat hepatic stellate cells (HSCs), and the possible relations between the underlying mechanism of the effect and TGF-β signaling via its receptors. Methods Freshly isolated HSCs from rat liver were subjected to treatment with lower concentrations of tetrandrine (0.4, 0.8, 1.6 and 3.2 μmol·L -1, respectively) at set point. The activation state of HSCs was determined by cell morphological features and detection of smooth muscle α-actin (α-SMA) using immunocytochemistry; HSCs were stimulated with TGF-β_1 (5 μg·L -1), in the presence or absence of an effective concentration of tetrandrine (1.6 μmol·L -1), which was determined formerly, and mRNA of TGF-β_1 and its typeⅠand typeⅡreceptors, Smad 3 and Smad 7 were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR), while protein levers of α-SMA, Smad 3 and Smad 7 were evaluated by Western blot. Results Tetrandrine 0.4-3.2 μmol·L -1 prevented morphological transformation of HSCs from the quiescent state to the activated one, and the α-SMA expression was inhibited. Tetrandrine (1.6 μmol·L -1) also inhibited TGF-β_1-stimulated α-SMA expression in HSCs. The results of RT-PCR showed a decreased TGF-β_1 mRNA comparing to an up-regulation of Smad 7 mRNA, and the up-regulation of Smad 7 protein was also observed by Western blot, while the expressions of type Ⅰand type Ⅱ TGF-β_1 receptors and Smad 3 were changed by tetrandrine insignificantly. Conclusion Tetrandrine at lower concentrations has a significant inhibiting effect on culture-activation and TGF-β_1-stimulated activation of rat HSCs. This effect of tetrandrine may be associated with the up-regulation Smad 7 which in turn blocks TGF-β_1 expression and its downstream signaling.

关 键 词：粉防己碱 肝星状细胞 转化生长因子-β1 SMADS SMAD7 信号转导 

分 类 号：R-332[医药卫生] R284.1