新型KATP开放剂埃他卡林对原代培养人肺动脉平滑肌细胞TGF-β1、PCNA mRNA表达的影响

Effects of iptakalim, a novel KATe opener, on expressions of transforming growth factor beta-1 and proliferating cell nuclear antigen in human pulmonary artery smooth muscle cell

目的观察新型ATP敏感性钾（KATP）开放剂埃他卡林（IPT）对原代培养人肺动脉平滑肌细胞转化生长因子β1（TGF-β1）和增殖细胞核抗原（PCNA）mRNA表达的影响。方法分离3～4级人肺小动脉，按照组织贴块法原代培养人肺动脉平滑肌细胞，用内皮素1（ET-1）诱导细胞增殖，应用实时荧光定量逆转录聚合酶链反应（RQ-RT-PCR）技术检测TGF-β1，和PCNA mRNA表达变化。结果ET-1（10nmol／L）诱导人肺动脉平滑肌细胞增殖的同时，TGF-β1、PCNA mRNA表达均增加；在相同条件下，加入ET-1（10nmol／L）的同时，分别在培养基中加入IPT 10^-7、10^-6、10^-5mol／L作用24h后，IPT呈浓度依赖性地抑制TGF-β1、PCNA mRNA表达；加入ET-1（10nmol／L）、IPT（10^-5mol／L）前30min，预先加入特异性KATP拮抗剂格列本脲（Glibenclimide，GLI）10^-7、10^-6、10^-5mol／L，GLI呈浓度依赖性地拮抗IPT的抑制作用。结论IPT通过开放KATP通道，浓度依赖性地抑制原代培养人肺动脉平滑肌细胞TGF-β1、PCNA mRNA表达，抑制人肺动脉平滑肌细胞增殖，有望今后成为治疗缺氧性肺动脉高压（HPH）、肺血管重构的药物。

Objective To explore the effects of iptakalim （IPT）, a novel ATP sensitive potassium （KATe） opener,on expressions of transforming growth factor beta-1 （TGF-β1） and proliferating cell nuclear antigen（PCNA） in primary cultured human pulmonary artery smooth muscle cells （HPASMCs）. Methods Under germ-free conditions,the smooth muscular layer was separated from human pulmonary arterioles （3-4 th divisions）. HPASMCs were cultured by tissue block method, and the cell proliferation was induced by endothelin-1（ET-1） in vitro. Fluorescence quantitative-reverse transcription-polymerase chain reaction （FQ- RT-PCR） was used to detect TGF-β1 and PCNA mRNA in HPASMCs. Results HPASMCs in the medium with ET-1 （10 nmol/L） showed excessive proliferation and higher expressions of TGF-β1 and PCNA mRNA. Compared with the value of the cells treated with ET-1 only, IPT at the concentrations of 10^-7 , 10^-6 and 10^-5 mol/L down-regulated the expressions of TGF-β1 and PCNA mRNA in a concentration-dependent manner. Glibenclimide（GLI） ,a specific KATP channel antagonist,at the concentrations of 10^-7 ,10^-6 and 10^-5 mol/L antagonized the effects of IPT on the expressions of TGF-β1 and PCNA mRNA in a concentration-dependent manner. Conclusions IPT has an inhibitory effect on expressions of TGF-β1 and PCNA mRNA in HPASMCs induced by ET-1 through activating KATp channels,and will be a promising drug for the treatment of hypoxic pulmonary hypertension and pulmonary arterial remodeling.