Participation of NF-κB and Janus Kinase-signal Transductors and Activation of Transcription Pathway in Rat VSMCs Proliferation Effect Mediated By Ang Ⅱ

ObjectiveTo further study the effect of Janus kinase-signal transductors and activation of transcription（Jak-STAT） signal pathway in VSMCs proliferation induced by Ang Ⅱ. MethodsVSMCs 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.ResultsAng 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 Ⅱ 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 translocation of STAT1 and NF-κB protein from cytoplasm to nuclei by immunofluorescence.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）.ConclusionWe have identified that Ang Ⅱ could 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-κB signal transduction pathways were activated and participated in the mechanism of VSMCs proliferation induced by Ang Ⅱ.