摘要
目的进一步探讨JakSTAT信号途径在血管紧张素Ⅱ介导的主动脉平滑肌细胞增殖效应的作用。方法培养大鼠主动脉平滑肌细胞并行免疫组织化学鉴定,用血管紧张素Ⅱ以不同时间梯度刺激传代培养的大鼠主动脉平滑肌细胞,采用BrdU法测定细胞增殖,裂解细胞后提取细胞总蛋白,分别经免疫共沉淀、Western印迹和细胞免疫荧光化学等方法分析胞内NFκB和Jak/STAT信号分子激活及表达的情况,行不同组间并与阴性对照组做对比。结果在6~30h的平滑肌细胞增殖实验中,6、12h时间段增值最明显;其中12h时AngⅡ组490nm处吸光度值(0.590±0.029)显著高于AG490+AngⅡ组(0.381±0.019),PDTC+AngⅡ组(0.481±0.024),氯沙坦+AngⅡ组(0.519±0.026)和SerumFree组(0.30±0.02),P<0.01。Western印迹显示AngⅡ组中NFκB及磷酸化的Jak2、STAT1分别在5、15、60min表达明显达高峰;免疫荧光则表明NFκB及STAT1分子随时间梯度可逆的由胞浆转至胞核,在AngⅡ刺激15min组中STAT1表达水平比对照组(P<0.01)及刺激60min高(P<0.05)。结论AngⅡ能导致VSMC增殖,同时NFκB和磷酸化的Jak2,STAT1表达增加并随刺激时间梯度改变。因此可说明在NFκB和Jak/STAT信号通路激活参与了血管紧张素Ⅱ导致的主动脉平滑肌细胞增殖作用。
Objective To further study the effect of Janus kinase-signal transductors and activation of transcription(Jak-STAT) signal pathway in VSMCs proliferation induced by Ang Ⅱ. Methods VSMCs were cultured and identified. Cells were activated with Ang Ⅱ at different times and verify its effect on VSMC proliferation by the method of bromodeoxyuridine incorporation. We extracted total protein and detected the activation and expression of nuclear factor-κB(NF-κB) and measured phosphorylation of Jak-STAT by immunoprecipitation, Western blot and immunofluorescence after cell disruption. Meanwhile we established negative group and different treatment groups. Results Ang Ⅱ caused significant increases in BrdU incorporation during 6-30 h of cells proliferation with the peak value at 6 and 12 h. The OD value of in 490 nm was higher in Ang Ⅱ groups (0. 590±0. 029) than AG490 Ang Ⅱ groups (0. 381±0. 019), PDTC±Ang H groups(0. 481±0. 024), losartan±Ang Ⅱ groups (0. 519±0. 026) and serum free groups ( 0.30 ±0.015), P〈0.01. Western blotting showed that expression of NF-κB and phosphorylation Jak-STAT molecules in VSMCs induced by the Ang Ⅱ reached to peak value at 5, 15, 60 min respectively. Meanwhile Ang Ⅱ induced a time-dependent reversible transloeation of STAT1 and NF-κB protein from cytoplasm to nuclei by immunofluoreseenee. The level of STAT1 in nuclei which was stimulated by Ang Ⅱ for 15 min was higher than that for 60 min stimulation (P〈0.05) and controls (P〈0.01 ). Conclusion We have identified that Ang Ⅱcould improve proliferation of VSMCs and expression of NF-κB and phosphorylation Jak-STAT and change with time gradient in VSMCs. Our studies therefore suggested that Jak-STAT and NF-κBsignal transduction pathways were activated and participated in the mechanism of VSMCs proliferation induced by Ang Ⅱ.
出处
《高血压杂志》
CAS
CSCD
北大核心
2006年第6期477-482,共6页
Chinese Journal of Hypertension
基金
国家自然科学基金(No.G30300133)