CAJ | 학술논문

目的探讨Ⅰ型磷酸酶抑制亚基1(PPI1)对大鼠乳鼠心肌细胞缺氧/复氧(H/R)损伤的保护作用及其机制.方法用PPI1野生型和活化型突变体表达质粒分别转染乳鼠心肌细胞,并建立乳鼠心肌细胞缺氧/复氧H/R模型,测定各组心肌细胞的存活率、丙二醛(MDA)、乳酸脱氢酶(LDH)的含量、caspase-3活性及超氧化物歧化酶(SOD)活力,此外用流式细胞术测定各组心肌细胞凋亡率,Western blot分析PPI1对凋亡相关蛋白表达及PI3K/Akt信号通路的影响.结果与正常组比较,模型组LDH、MDA含量、caspase-3活性及细胞凋亡率增高(P<0.05),细胞存活率和SOD活性降低(P<0.05);PPI1活化型突变体转染组细胞的LDH、MDA含量、caspase-3活性和细胞凋亡率则降低,细胞存活率和SOD活性升高,与缺氧/复氧组比较各实验指标差异均具有统计学意义(P<0.05).Western blot表明该组细胞P53、Bax 表达下调,pAkt表达上调.结论 PPI1活化型突变体对H/R造成的心肌细胞损伤具有保护作用,其机制与稳定心肌细胞膜、减轻氧自由基损伤及减少细胞凋亡有关.
목적 탐토Ⅰ형린산매억제아기1(PPI1)대대서유서심기세포결양/복양(H/R)손상적보호작용급기궤제.방법 용PPI1야생형화활화형돌변체표체질립분별전염유서심기세포,병건립유서심기세포결양/복양H/R모형,측정각조심기세포적존활솔、병이철(MDA)、유산탈경매(LDH)적함량、caspase-3활성급초양화물기화매(SOD)활력,차외용류식세포술측정각조심기세포조망솔,Western blot분석PPI1대조망상관단백표체급PI3K/Akt신호통로적영향.결과 여정상조비교,모형조LDH、MDA함량、caspase-3활성급세포조망솔증고(P<0.05),세포존활솔화SOD활성강저(P<0.05);PPI1활화형돌변체전염조세포적LDH、MDA함량、caspase-3활성화세포조망솔칙강저,세포존활솔화SOD활성승고,여결양/복양조비교각실험지표차이균구유통계학의의(P<0.05).Western blot표명해조세포P53、Bax 표체하조,pAkt표체상조.결론 PPI1활화형돌변체대H/R조성적심기세포손상구유보호작용,기궤제여은정심기세포막、감경양자유기손상급감소세포조망유관.
Objective To observe the effects of expression of PPI1 on cardiac myocyte of neonatal mice injured by hypoxia/reoxygenation, and to explore its possible mechanism. Methods Plasmids containing wild type or activated mutant of PPI1 gene were transfected into cardiac myocyte of neonatal mice, and the myocardial hypoxia/reoxygenation model was established.The cell viability,activity of superoxide dismutase (SOD) and caspase-3, the content of malondialdehyde (MDA) and lactate dehydrogenase (LDH) were measured. Moreover, Flow cytometry was used to analyze the cell apoptosis, and immunoblotting was used to determine apoptosis related proteins and the effects of PPI1 on PI3K/Akt signal transduction. Results Hypoxia/reoxygenation resulted in significantly increased MDA and LDH contents, caspase-3 activity and apoptosis of the cardiac myocytes (P<0.05 ), but lowered SOD activity and cell viability (P<0.05 ). The MDA and LDH contents,caspase-3 activity and apoptotic rate were significantly lower but cell viability SOD content significantly higher in PPI1 activated mutant gene transfected cells(P<0.05 ), moreover, the expression of p53, Bax were down-regulated, while the expression of pAkt were up-regulated. Conclusion PPI1 activated mutant gene can significantly reduce hypoxia/reoxygenation-induced oxidative stress in cardiac myocytes, which might involve stabilizing the membrane of myocardium, restricting oxygen free radical injury, and reducing the apoptotic rate of the cardiac myocytes.