低温缺氧/复氧后大鼠心肌成纤维细胞对心肌H9c2细胞间通讯的影响

Effect of rat cardiac fibroblasts on H9c2 cardiomyocytes intercellular communication after hypothermia hypoxia/reoxygenation

目的观察低温缺氧/复氧(hypothermia hypoxia/reoxygen,H/R)后大鼠心肌成纤维细胞(rat cardiac fibroblasts,RCFs)对心肌H9c2细胞间通讯的影响并探讨其可能机制。方法将RCFs细胞与H9c2细胞以2:1数量比Transwell共培养后随机分为6组。其中T+AngⅡ组及H/R⁃T+AngⅡ组加入1.5 nmol/L AngⅡ,T+ARB组及H/R⁃T+ARB组加入1 nmol/L缬沙坦。T组、T+AngⅡ组及T+ARB组进行正常培养,H/R⁃T组、H/R⁃T+AngⅡ及H/R⁃T+ARB组进行H/R处理。检测各组培养液中AngⅡ含量;H9c2细胞Cx43、ERK1/2表达量及磷酸化及细胞间通讯情况。结果与T组相比,H/R⁃T组及T+AngⅡ组H9c2细胞ERK1/2、Cx43表达及磷酸化水平降低(P<0.05),细胞间通讯减弱(P<0.05);T+ARB组H9c2细胞ERK1/2、Cx43表达及磷酸化水平增高(P<0.05),细胞间通讯增强(P<0.05)。与H/R⁃T组相比,H/R⁃T+AngⅡ组H9c2细胞ERK1/2、Cx43表达及磷酸化水平降低(P<0.05),细胞间通讯减弱(P<0.05);H/R⁃T+ARB组H9c2细胞ERK1/2、Cx43表达及磷酸化水平增加(P<0.05),细胞间通讯增强(P<0.05)。结论H/R处理后,RCFs细胞分泌增多的AngⅡ可能通过抑制H9c2细胞MAPK/ERK通路下调Cx43表达,导致H9c2细胞间通讯减弱。

Objective To observe the effect on myocardial H9c2 cells gap junction intercellular communi⁃cation(GJIC)by rat cardiac fibroblasts(RCFs)after hypothermia hypoxia/reoxygen(H/R)and to explore the pos⁃sible mechanisms.Methods After co⁃cultured of RCFs cells with H9c2 cells in a 2:1 number ratio by Transwell,cells was randomly divided into 6 groups.The T+AngⅡgroup and H/R⁃T+AngⅡgroup were added 1.5nM AngⅡ,and the T+ARB group and H/R⁃T+ARB group were added 1nM valsartan.The T group,T+AngⅡgroup and T+ARB group were cultured normally,and the H/R⁃T group,H/R⁃T+AngⅡand H/R⁃T+ARB group were treated with H/R.The AngⅡconcentration in the culture medium;the expression and phosphorylation of Cx43 and ERK1/2;and GJIC of H9c2 cells were detected.Results Compared with the T group,the expression and phosphorylation of ERK1/2 and Cx43 were decreased(P<0.05)and GJIC was diminished(P<0.05)in H9c2 cells in the H/R⁃T and T+Ang II group;he expression and phosphorylation of ERK1/2 and Cx43 were increased(P<0.05)and GJIC was enhanced(P<0.05)in H9c2 cells in the T+ARB group.Compared with H/R⁃T group,he expression and phosphorylation of ERK1/2 and Cx43 were decreased(P<0.05)and GJIC was diminished(P<0.05)in H9c2 cells in H/R⁃T+Ang II group;and the expression and phosphorylation of ERK1/2 and Cx43 were increased(P<0.05)and GJIC was diminished(P<0.05)in H9c2 cells in H/R⁃T+ARB group.Conclusion After H/R,in⁃creased AngⅡsecretion by RCFs may downregulate Cx43 expression by inhibiting the MAPK/ERK pathway in H9c2 cells,resulting in diminished GJIC between H9c2 cells.