KATP开放剂对骨髓间充质干细胞凋亡和向心肌细胞转化心肌标志物的影响

Effects of KATP opener on apoptosis and cardiac biomarkers in rat bone marrow mesenchymal stem cells during differentiation into cardiomyocytes

目的 研究KATP开放剂对大鼠骨髓间充质干细胞（BM-MSCs）凋亡和向心肌细胞转化心肌标志物的影响。方法 培养4周雄性SD大鼠的BM-MSCs，以二氮嗪（Dia）和吡那地尔（Pin）预处理细胞，H2O2诱导细胞凋亡，用流式细胞仪检测细胞凋亡率。在KATP开放剂处理2h后提取各组细胞总mRNA，实时定量PCR法检测心肌特异基因肌钙蛋白I（cTnI）、肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）、缝隙连接蛋白43（Cx43）以及α重链蛋白（α-MHC）的mRNA表达情况。提取细胞蛋白，Western印迹法检测cTnI、CK、CK-MB蛋白的表达情况。结果 Dia和Pin 50mol/L预处理可明显降低BM-MSCs凋亡率（P＜0.05）。Dia和Pin处理2h，能使BM-MSCs的cTnI、CK、Cx43 mRNA表达显著增加（P＜0.05）；同时明显增加CK、CK-MB蛋白表达（P＜0.05）。结论 Dia和Pin能增加BM-MSCs向心肌细胞的转化心肌标志物的表达，并具有抗凋亡的作用。

Objective To determine the effect of ATP sensitive potassium channel （KATP） openers on the apoptosis of rat bone marrow mesenchymal stem cells （BM-MSCs） and on the cardiac biomarkers in the differentiation of the cells into cardiomyocytes. Methods BM-MSCs Were isolated from 4-week-old male SD rats, and then amplified and preconditioned by KATP openers, diazoxide （Dia） and pinacidil （Pin）. The cell apoptosis was induced by H2O2, and the apoptosis rate was detected by flow cytometry. After the BM-MSCs were treated with 2 KATP openers respectively for 2h, the total mRNA was extracted for the expression levels of cardiac specific genes, including cardiac-specific troponin I （cTnI）, creatine kinase （CK）, creatine kinase isoenzyme （CK-MB）, connexin 43 （Cx43） and α-heavy chain protein （α-MHC）. Western blotting was used to detect the expression of cTnI, CK and CK-MB. Results Both Dia and Pin of 50mol/L significantly decreased the apoptosis rate of BM-MSCs （P〈0.05）. After 2h preconditioning, Dia and Pin obviously increased the mRNA levels of cTnI, CK, CK-MB and Cx43 （P〈0.05）, and enhanced the protein levels of CK and CK-MB （P〈0.05）. Conclusion KATP openers enhance the expression of cardiac biomarkers in the differentiation of BM-MSCs into cardiomyocytes, and also exert anti-apoptotic effect.