CAJ | 학술논문

目的观察骨髓间质干细胞移植治疗心肌梗死时对myocardin相关转录因子-A(MRTF-A)的影响及MRTF-A对凋亡相关基因bcl-2表达的调控作用.方法采用随机数字表法将30只大鼠分为假手术组、心肌梗死组和干细胞移植组,每组10只.假手术组大鼠实行手术但不结扎冠状动脉,心肌梗死组结扎冠状动脉建立心肌梗死模型,干细胞移植组心肌梗死模型形成后移植骨髓间质干细胞.术后1周,采用TUNEL法检测心肌细胞凋亡、激光共聚焦法和Western blot法检测bcl-2及MRTF-A表达.体外培养心肌细胞并转染MRTF-A表达质粒或共转染MRTF-A表达质粒及bcl-2报告基因质粒或其突变体,经Western blot法及荧光素酶法确定bcl-2蛋白表达及转录活性.结果假手术组、心肌梗死组和干细胞移植组的心肌凋亡细胞分别为(4.05±1.56)％、(62.38±8.41)％和(22.36±6.17)％,心肌梗死组明显高于假手术组(P＜0.05)和干细胞移植组(P＜0.05);心肌梗死组的MRTF-A及bcl-2蛋白表达明显低于假手术组,而于细胞移植组则高于心肌梗死组(P均＜0.05);在体外培养的原代心肌细胞中,MRTF-A转染量为0.2、0.4和0.6 μg时,bcl-2的蛋白表达及转录活性均明显高于MRTF-A转染量为0μg时(P＜0.01);将bcl-2启动子上的CArG Box突变后,bcl-2的转录活性的差异无统计学意义.结论骨髓间质干细胞移植能有效抑制心肌梗死诱导的大鼠心肌细胞调亡,其机制可能与骨髓间质干细胞移植后心肌细胞MRTF-A表达增高并继而调控抗凋亡基因bcl-2转录表达有关.
목적 관찰골수간질간세포이식치료심기경사시대myocardin상관전록인자-A(MRTF-A)적영향급MRTF-A대조망상관기인bcl-2표체적조공작용.방법 채용수궤수자표법장30지대서분위가수술조、심기경사조화간세포이식조,매조10지.가수술조대서실행수술단불결찰관상동맥,심기경사조결찰관상동맥건립심기경사모형,간세포이식조심기경사모형형성후이식골수간질간세포.술후1주,채용TUNEL법검측심기세포조망、격광공취초법화Western blot법검측bcl-2급MRTF-A표체.체외배양심기세포병전염MRTF-A표체질립혹공전염MRTF-A표체질립급bcl-2보고기인질립혹기돌변체,경Western blot법급형광소매법학정bcl-2단백표체급전록활성.결과 가수술조、심기경사조화간세포이식조적심기조망세포분별위(4.05±1.56)％、(62.38±8.41)％화(22.36±6.17)％,심기경사조명현고우가수술조(P＜0.05)화간세포이식조(P＜0.05);심기경사조적MRTF-A급bcl-2단백표체명현저우가수술조,이우세포이식조칙고우심기경사조(P균＜0.05);재체외배양적원대심기세포중,MRTF-A전염량위0.2、0.4화0.6 μg시,bcl-2적단백표체급전록활성균명현고우MRTF-A전염량위0μg시(P＜0.01);장bcl-2계동자상적CArG Box돌변후,bcl-2적전록활성적차이무통계학의의.결론 골수간질간세포이식능유효억제심기경사유도적대서심기세포조망,기궤제가능여골수간질간세포이식후심기세포MRTF-A표체증고병계이조공항조망기인bcl-2전록표체유관.
Objective To observe the impact of mesenchymal stem cells (BMSCs) transplantation on myocardial myocardin-related transcription factor-A (MRTF-A) and bcl-2 expression in rats with experimental myocardial infarction (MI).Methods Thirty rats were randomly divided into sham,MI and MI + BMSCs (1 × 106 injected into 4 infarct points immediately post coronary artery ligation) groups (n =10 each).One week later,TUNEL was used to detect cardiomyocyte apoptosis,the myocardial expression of MRTF-A and bcl-2 was detected by laser scanning confocal microscope and Western blot.In vitro plasmid of MRTF-A and co-transfection with plasmids of MRTF-A and bcl-2 or mutated bcl-2 transfection into cardiomyocyte was applied to evaluate the relationship between MRTF-A and bcl-2.Results The number of apoptotic cardiomyocytes in the sham group,MI group and MI + BMSCs group were (4.05 ± 1.56) ％,(62.38 ± 8.41) ％ and (22.36 ±+ 6.17) ％,respectively (P ＜ 0.05).The protein expression of MRTF-A and bcl-2 in the MI group were significantly lower than those in sham group,while significantly upregulated in MI + BMSCs group (P ＜ 0.05 vs.MI).In cultured neonatal rat cardiomyocyte,the expression of bcl-2 protein was significantly upregulated after transfection with MRTF-A plasmid,and bcl-2-luciferase activity significantly increased after co-transfection with plasmids of MRTF-A and bcl-2-luciferase,however,the positive regulatory effect of MRTF-A was abolished after transfection with mutated bcl-2.Conclusion Mesenchymal stem cells transplantation can effectively reduce cardiomyocyte apoptosis in this rat MI model,and upregulate the expression of MRTF-A.Consequent up-regulated bcl-2 expression might be involved in the beneficial effects of BMSCs transplantation in this model.