【摘要】 目的研究线粒体ATP敏感钾通道(mitoKATP)对哮喘气道平滑肌细胞(ASMCs)表型转化的影响。方法腹腔注射和雾化吸入制备哮喘大鼠模型,取哮喘及正常大鼠ASMCs,分为以下6组进行干预:正常对照组;正常+mi-toKATP开放剂diazoxide组;正常+mitoKATP阻断剂5-HD组;哮喘对照组;哮喘+diazoxide组;哮喘+5-HD组。激光共聚焦显微镜检测各组ASMCs R-123荧光强度以反映线粒体膜电位(Δψm),Western blot法检测各组细胞α-肌动蛋白(α-actin)表达量。结果①与正常对照组比较,哮喘对照组R-123荧光强度明显增强,α-actin表达明显下调(均P<0.05)。②diazoxide干预ASMCs 24 h后,正常及哮喘ASMCs R-123荧光强度均明显增强(均P<0.05);正常ASMCsα-actin表达量无明显变化(P>0.05),但哮喘ASMCsα-actin表达量明显增加(P<0.05)。结论diazoxide引起mitoKATP开放,并逆转哮喘ASMCs由收缩型向合成型发生的表型转化。更多还原

【Abstract】 Objective To investigate the impact of mitochondrial ATP-sensitive K+ channel(mitoKATP) on the phenotypic modulation of airway smooth muscle cells(ASMCs) in asthmatic rats.MethodsThe rat asthmatic model was established by peritoneal injection and aerosol inhalation.The ASMCs from normal and asthmatic rats were divided into following 6 groups:normal control group(ASMCs cultured under normoxia);diazoxide group(ASMCs cultured under normoxia+diazoxide,an opener of mitoKATP);5-HD group(ASMCs cultured under normoxia+5-HD,an antagonist of mitoKATP);asthma group(ASMCs in asthmatic rats cultured under normoxia);asthma+diazoxide group(ASMCs in asthmatic rats cultured with diazoxide for 24 h);asthma+5-HD group(ASMCs in asthmatic rats cultured with 5-HD for 24 h).The changes in fluorescence intensity were tested by using rhodamine fluorescence(R-123) technique,which could reflect the relative change of mitochondrial membrane potential.Western blot was used to detect the expression of α-actin protein in rat ASMCs.Results① As compared with normal control group,the intensity of R-123 fluorescence was significantly increased,and the expression of α-actin in asthma group significantly down-regulated(P<0.05).② As compared with normal control group,the intensity of R-123 fluorescence was significantly increased in diazoxide group and asthma+diazoxide group(all P<0.05),and the expression level of α-actin in asthma+diazoxide group was obviously increased(P<0.05),but there was no significant changes in diazoxide group(P>0.05).ConclusionDiazoxide can open the mitoKATP,leading to the increase in the expression level of α-actin protein,which can reverse the phenotypic modulation from a contractile to a synthetic type in ASMCs of asthmatic rats.更多还原