腺苷A2A受体激活抑制低氧性肺动脉平滑肌细胞增殖的机制

摘要

Objective To study the effects of adenosine A2A receptor on the proliferation induced by hypoxia of pulmonary artery smooth muscle cells(PASMCs) in rats,and its mechanism.Methods PASMCs were isolated from rat small pulmonary arteries,and verified by immunocytochemistry.The proliferation of PASMCs in vitro culture were divided into 7 groups:control group,chronic hypoxia group,hypoxia with diazoxide group,hypoxia with 5-HD group,hypoxia with CGS21680 group,hypoxia with CGS21680 and diazoxide group,hypoxia with CGS21680 and 5-HD group.The effects of adenosine A2A receptor on the PASMCs in vitro culture were measured by CCK-8.The expression of A2AAR gene was determined by real-time RT-PCR.Results The absorbance of CCK-8 was increased in hypoxia group(P ＜ 0.01),which could be inhibited by CGS-21680.CGS-21680 with 5-HD group had synergy to make the absorbance higher.The expression of A2AAR gene in chronic hypoxia group and CGS-21680 intervene group,especially CGS-21680 with 5-HD group,was obviously higher than that of control group.Conclusion CGS-21680 can inhibit the proliferation of hypoxic PASMCs.The blocking mitochondrial KATP channels may be an important mechanism.%目的 研究腺苷A2A受体(adenosine A2A receptor,A2AR)激活对低氧肺动脉平滑肌细胞(pulmonary artery smooth muscle cells,PASMCs)增殖的影响及其作用机制.方法 体外培养SD大鼠PASMCs,经免疫组化鉴定,离体培养分7组:①正常对照组(control group)；②低氧组(chronic hypoxia,CH)；③CH+线粒体敏感性钾通道(MitoKArP)开放剂diazoxide组；④CH+MitoKATP阻断剂5-HD组；⑤CH+A2AAR特异性激动剂CGS21680组；⑥CH+CGS21680+diazoxide组；⑦CH+CGS21680 +5-HD组.CCK-8染色法检测CGS21680对离体大鼠PASMCs增殖的影响,实时荧光定量法检测CGS-21680对大鼠PASMCs腺苷A2A受体基因表达的影响.结果 低氧使CCk-8吸光度(absorbance,A)值升高(P＜0.01),CGS-21680干预使低氧下A值明显下降,且CGS-21680和5-HD协同作用下效果更明显.Real-time RT PCR显示低氧和CGS-21680干预组A2A AR表达显著升高(P＜0.01),且以CGS-21680联合5-HD组升高最明显.结论 A2AAR激活剂CGS-21680抑制低氧PASMCs增殖,可能与阻断MitoKATP通道开放有关.