人脐血间充质干细胞抗缺氧诱导心肌细胞凋亡的作用☆

背景：抗细胞凋亡成为心力衰竭生物治疗的一个新方向。近年研究发现成体间充质干细胞在一定条件下可转化成心肌样细胞，亦可通过分泌多种细胞因子，促进心脏血管形成和减少细胞凋亡。目的：观察人脐血间充质干细胞对缺氧诱人心肌细胞凋亡的保护作用。方法：将人心肌细胞细胞复苏后，接种在6孔细胞培养板(对照组)和Transwell 3412培养板中；将人脐血间充质干细胞接种在Transwell插件的可渗透性滤膜上；将上述2组细胞置于体积分数95%N2+体积分数5%CO2缺氧环境下缺氧培2，4，12，24 h；检测各组心肌细胞的凋亡率。ELLES法检测细胞条件培养基内胰岛素样生长因子1的浓度。结果与结论：第3代后人脐血间充质干细胞及原代心肌细胞均有胰岛素样生长因子分泌，但人脐血间充质干细胞条件培养基内胰岛素样生长因子1的浓度明显高于人心肌细胞。缺氧可以诱导心肌细胞凋亡，在短期和持续性缺氧的条件下，人脐血间充质干细胞对缺氧诱导的心肌细胞凋亡有保护作用，且人脐血间充质干细胞组心肌细胞凋亡率低于对照组( P < 0.05)。提示人脐血间充质干细胞对缺氧诱导的人心肌细胞凋亡有保护作用，这种保护作用可能与通过细胞间直接接触和旁分泌细胞因子有关。

Inhibitory effects of human umbilical cord blood-derived mesenchymal stem cells on hypoxia-induced cardiomyocyte apoptosis

BACKGROUND: Anti-apoptosis is a new direction of bio-therapy of heart failure. Recent studies have found that adult mesenchymal stem cells (MSCs) under certain conditions can be induced to differentiate into cardiomyogenic cells. By secreting a variety of cytokines, MSCs can promote cardiac angiogenesis and reduce cardiomyocyte apoptosis.OBJECTIVE: To investigate the anti-apoptotic effects of human umbilical cord blood (UCB)-derived MSCs on hypoxia-induced human cardiomyocytes apoptosis.METHODS: Following resuscitation, human cardiomyocytes were incubated in a 6-well plate (control group) and Transwell 3412 plate. Human UCB-derived MSCs were incubated on Transwell-inserted permeable filter membrane. Cells in both groups were incubated in 95% N2+ 5% CO2 hypoxia condition for 2, 4, 12 and 24 hours. Apoptotic rate of cardiomyocytes was detected in both groups. The level of insulin-like growth factor-1 (IGF-1) in the conditioned medium was measured with enzyme linked immunosorbent assay kit. RESULTS AND CONCLUSION: From the third passage, human UCB-derived MSCs and primary culture of cardiomyocytes had IGF, but IGF-1 levels were significantly greater in human UCB-derived MSCs conditioned medium than human cardiomyocytes medium. Hypoxia can induce cardiomyocyte apoptosis, and human UCB-derived MSCs exerted protective effects on hypoxia-induced cardiomyocyte apoptosis under short-term and persistent hypoxia. Cardiomyocyte apoptotic rate was lower in the human UCB-derived MSCs group than control group (P < 0.05). The results have demonstrated that human UCB-derived MSCs exhibit significant anti-apoptotic effects on hypoxia-induced human cardiomyocytes. This protective effect may be associated with cell to cell direct interaction and paracrine of cytokine.