中文摘要：

目的 探讨Apelin对人诱导性多能干细胞（hiPSC）的心肌定向分化作用.方法 hiPSC经悬浮法诱导形成拟胚体,分为Apelin处理组（Apelin组）和对照组.Apelin组在高糖DMEM培养液中加入10 μmol/ml Apelin,分别于第3、7、11、15、21天采用RT-PCR、Western blot法检测及免疫荧光染色,观察干细胞全能性标记物Oct4、心肌祖细胞标记物Nkx 2.5、心肌特异性肌钙蛋白I（cTnI）的表达变化.结果 Apelin组iPSC在诱导分化后第3天Oct4和Nanog基因表达水平明显降低,分别为同期对照组的（63.2±10.1）%和（51.7±1.6）%（P〈0.01）;诱导分化后第7天Nkx 2.5和cTnI基因表达水平明显升高,分别为同期对照组的（162.4±22.5）%和（250.6±22.3）%（P〈0.05,P〈0.01）;诱导分化后第15天时,cTnI表达为同期对照组的（156.2±6.4）%（P〈0.05）;免疫荧光染色显示,cTnI阳性细胞明显多于对照组.结论 Apelin可明显促进hiPSC的心肌定向分化.

英文摘要：

Objective To study the role of apelin in promoting differentiation of human induced pluripotent stem cells （hiPSC） to cardiomyocytes. Methods Embryoid bodies were formed in sus- pension of hiPSC. The hiPSC were divided into apelin treatment group and control group. The hiPSC in apelin treatment group were cultured in DMEM containing 10 μmol/ml apelin. Expres- sions of Oct4 （a marker of hiPSC）, Nkx 2.5 （a marker of myocardial ancestral cells） and cTnI （a marker of myocardial specific troponin） in hiPSC were detected by RT-PCR and Western blot respectively with immunofluorescence staining on clays 3,7, 11,15,21 after apelin treatment. Results The expression levels of Oct4 and Nanog gene were significantly lower whereas those of Nkx 2.5 and cTnI were significantly higher in apelin treatment group than in control group on clays 3 and 7 （63.2%±10. 1% v,; 51.7%±1. 6%,162.4%±22.5% vs 250.6%±22.3%,P〈 0. 05 , P〈0. 01）. The expression level of cTnI was 56.2% higher in apelin treatment group than in control group on day 15. Immunofluorescence staining showed that the number of cTnl positive cells was greater in apelin treatment group than in control group. Conculsion Apelin can signifi- cantly promote the differentiation of hiPSC to cardiomyoctes.