Li Tao, Leng Xi-Sheng, Zhu Ji-Ye, Guo Yan-Tong, Wei Yu-Hua
Department of Hepatobiliary Surgery, Peking University People's Hospital, Beijing, China.
Zhonghua Gan Zang Bing Za Zhi. 2007 Dec;15(12):902-5.
To investigate the effect of protein kinase C (PKC)/transforming growth factor beta 1 (TGF beta1) pathway on activation of hepatic stellate cells (HSC).
HSC rHSC-99 cell line was used in three groups in this study. Group A served as a control. In group B the HSC were incubated with PKC agonist PMA (0.5 micromol/L), and in group C the cells were incubated with PKC inhibitor calphostin C (100 nmol/L). The PKC activities were detected at different incubation time points (0, 3, 6, 12 and 24 h). Western blot and RT-PCR were used to detect the expression of TGF beta1, Smad 4, collagen type I, III and alpha-smooth muscle actin (alpha-SMA) at the 24 h point. Cell proliferation was assessed by MTT colorimetric assay.
PMA increased the activity of PKC significantly, whereas calphostin C inhibited the activity of PKC. The increased activity of PKC promoted the HSC to express TGF beta1, Smad 4, collagen type I, III and alpha-SMA. In comparison with the controls, the expressions of TGF beta1, Smad 4, collagen type I, III and alpha-SMA increased 4.8, 13.1, 2.4, 1.8 and 1.3 fold respectively (P < 0.01). PKC promoted the proliferation of HSC. The above effects were inhibited by the inhibition of PKC activity.
Changing of PKC activity can regulate and control the expression of TGF beta1, which may play a role in regulating the activation of HSC.
探讨蛋白激酶C（PKC）/转化生长因子β1（TGFβ1）信号通路对肝星状细胞（HSC）激活的影响。
本研究采用HSC rHSC-99细胞系，分为三组。A组作为对照组。B组用PKC激动剂佛波酯（PMA，0.5 μmol/L）孵育HSC，C组用PKC抑制剂藤黄菌素（calphostin C，100 nmol/L）孵育细胞。在不同孵育时间点（0、3、6、12和24小时）检测PKC活性。在24小时时间点，采用蛋白质印迹法和逆转录-聚合酶链反应（RT-PCR）检测TGFβ1、Smad 4、Ⅰ型和Ⅲ型胶原蛋白以及α-平滑肌肌动蛋白（α-SMA）的表达。采用MTT比色法评估细胞增殖。
PMA显著增加PKC活性，而藤黄菌素抑制PKC活性。PKC活性增加促进HSC表达TGFβ1、Smad 4、Ⅰ型和Ⅲ型胶原蛋白以及α-SMA。与对照组相比，TGFβ1、Smad 4、Ⅰ型和Ⅲ型胶原蛋白以及α-SMA的表达分别增加了4.8倍、13.1倍、2.4倍、1.8倍和1.3倍（P < 0.01）。PKC促进HSC增殖。PKC活性的抑制可抑制上述作用。
PKC活性的改变可调控TGFβ1的表达，这可能在调节HSC激活中发挥作用。
