EGFR siRNA通过阻碍STAT3磷酸化抑制大鼠星形胶质细胞活化

摘要

Aim To observe the expression of epider-mal growth factor receptor ( EGFR) in cerebral tissues around hematomas after intracerebral hemorrhage, and explore the effects of EGFR on activation of astrocytes derived from rats and the involved mechanisms. Meth-ods The specimens of cerebral tissues around hemo-tomas after intracerebral hemorrhage undergoing hemo-tomas removal operation were collected and then divid-ed into 4 groups according to the time of intracerebral hemorrhage: 10 d groups. Each group included 20 cases. At the same time, 20 dropped brain tissues distant to hemorrhage in the operative process were collected as control group. Immunohistostaining and Western blot were used to measure the expression of EGFR. After isolation and culturing, the astrocytes of rat cortex were treated with culture solution ( control group) , CNTF that was used to activate astrocytes, scramble siRNA + CNTF and EGFR siRNA +CNTF for 24h, respectively. The ex-pression of glial fibrillary acidic protein ( GFAP) mR-NA was detected through fluorescence real-time quanti-tative PCR. In addition, the protein levels of GFAP, signal transducers and activators of transcription 3 ( STAT3 ) and phosphorylated STAT3 ( p-STAT3 ) were examined using Western blot. Results With the ex-tension of intracerebral hemorrhage time, positive sig-nal index and protein expression levels of EGFR gradu-ally elevated, reached the peak on 6 ~10d, and then decreased after 10 d. There was statistical difference ( P0. 05 ) . Conclusions EGFR expression is upregulated in the cerebral tissues around hemotomas after intracerebral hemorrhage. Gene silence of EGFR contributes to suppressing the activation of astrocytes derived from rats, which may be involved in the block-ade of STAT3 phosphorylation.%组)、睫状神经营养因子( CNTF,用于活化星形胶质细胞)、Scramble siRNA+CNTF、EGFR siRNA+CNTF处理24 h,荧光实时定量PCR检测神经胶质原纤维酸性蛋白( GFAP) mR-NA表达,并采用Western blot分析GFAP、信号传导蛋白和转录激活物3( STAT3)、磷酸化 STAT3( p-STAT3)蛋白表达。结果随着脑出血时间的延长,EGFR阳性信号指数及蛋白表达水平逐渐升高,6~10 d达到高峰,10 d后仍处于较高水平,两两比较差异均有显著性( P0．05)。结论 EGFR在脑出血后血肿周围脑组织中表达升高,EGFR基因沉默有助于抑制大鼠星形胶质细胞活化,其机制可能与阻碍STAT3磷酸化有关。