中文摘要：

目的：研究血管紧张素Ⅱ（AngⅡ）诱导大鼠血管平滑肌细胞（VSMC）肥大的信号转导途径中PKCζ与Raf的作用关系。方法：[^3H]-亮氨酸掺入反映VSMC蛋白质合成；Western blotting检测ERK1／2和PKCζ表达；免疫共沉淀实验检测信号分子间的相互作用。结果：AngⅡ刺激可引起VSMC[^3H]-亮氨酸掺入显著增加，PKC非特异性抑制剂和PKCζ假底物抑制剂（PS—PKCζ）均明显抑制AngⅡ引起的作用。PS—PKCζ预处理使AngⅡ刺激VSMC的ERK1／2磷酸化水平明显降低。转染dominant negative Raf（Raf S621A）质粒的VSMC中的PKCζ磷酸化水平与转染野生型Raf质粒无明显差异。AngⅡ刺激使Ras与Raf结合增加，但PKCζ抑制剂不影响AngⅡ引起的Raf与Ras的结合。转染Raf S621A抑制Raf活化后，AngⅡ引起的ERK1／2磷酸化水平降低。结论：在VSMC中，PKCζ亚型参与AngⅡ诱导的VSMC蛋白合成，但PKCζ可能通过非依赖Raf的途径激活ERK1／2。

英文摘要：

AIM： To investigate the crosstalk of PKCζ isoform with Raf in the signal pathway of vascular smooth muscle cell （VSMC） hypertrophy induced by angiotensin Ⅱ （Ang Ⅱ ）. METHODS： The protein synthesis of VSMCs was measured by [^3H] - thymidine incorporation. The expression of PKCζ and ERK1/2 proteins were detected by Western blotting. The interaction of the signal molecules was examined by immunoprecipitation. RESULTS： Pretreatment of VSMCs with PKC non- specific inhibitor stanrosporine or PKCζ pseudesnhstrate inhibitor （PS- PKCζ）, the Ang Ⅱ - induced [^3H] -thymicline incorporation into VSMCs was decreased markedly. PS -PKCζ pretreatment significantly decreased phesphorylation of ERK1/2 induced by Ang Ⅱ. Compared with VSMCs transfected with wild type Raf, PKCζ phosphorylation was similar in the VSMCs transfected with dominant negative Raf （Raf S621A）. Immunoprecipitation analysis showed that Ang Ⅱ stimulated the association of Ras with Raf, but PKCζ inhibitor had no influence on Ang Ⅱ - induced conjugation of Ras with Raf. After Raf activity was inhibited by Raf S621A, Ang Ⅱ - induced ERK1/2 phesphorylation level declined. CONCLUSION： These results suggest that PKCζ is involved in protein synthese induced by Ang Ⅱ in VSMCs, but PKCζ induces ERK1/2 activation via a Raf- independent pathway.