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背景:研究显示磷酸鞘胺醇1(sphingosine-1-phosphate,S1P)可诱导脂肪干细胞分化成平滑肌细胞。S1P是否可替代5-氮杂胞苷作为间充质细胞分化为心肌细胞的诱导剂尚不清楚。目的:探讨S1P促进在不同培养液诱导下的人脐带间充质干细胞向心肌样细胞分化的可能性。方法:收集培养人心肌细胞的条件培养基(cardiomyocytes condition medium,CMCM),分别用CMCM和(或)S1P培养人脐带间充质干细胞,在培养的第1,5,10天,观察人脐带间充质干细胞的形态学变化。培养10d后,应用免疫细胞化学和膜片钳鉴定细胞表型及细胞功能。结果与结论:随着培养时间的延长,CMCM组和CMCM+S1P组的一些细胞逐渐增大,拉长,与邻近细胞连接并形成肌管样结构,其中一些细胞聚集成簇。在CMCM+S1P组中,细胞出现特殊的垂直对齐梯田状,类闰盘样排列。同时,免疫细胞化学染色结果显示,CMCM组和CMCM+S1P组中一些细胞强烈表达心肌特异性抗体(心肌肌球蛋白重链和横纹肌辅肌动蛋白α),说明人脐带间充质干细胞在CMCM诱导下可分化为心肌样细胞。膜片钳仅在CMCM+S1P组的部分细胞记录到一个快速上行,但无平台期的动作电位,以及一个电压依赖性内向电流和一个电压依赖性外向电流。说明S1P在促进人脐带间充质干细胞向心肌样细胞分化和功能整合中发挥关键作用。
BACKGROUND: Studies have shown that sphingosine-1-phosphate (S1P) induces the differentiation of adipose-derived stem cells into smooth muscle cells. Whether S1P can substitute 5-azacytidine as an inducer of mesenchymal cells to differentiate into cardiomyocytes is unclear. Objective: To investigate the potential of S1P to promote differentiation of human umbilical cord mesenchymal stem cells into cardiomyocyte-like cells induced by different culture media. Methods: Human cardiomyocyte conditioned medium (CMCM) was collected and cultured with CMCM and / or S1P respectively. Human umbilical cord mesenchymal stem cells were cultured on day 1, day 5 and day 10, Morphological changes of MSCs. After culturing for 10 days, immunocytochemistry and patch clamp were used to identify cell phenotype and cell function. RESULTS AND CONCLUSION: With the prolongation of culture time, some cells in CMCM group and CMCM + S1P group gradually increased, elongated, connected with neighboring cells and formed myotube-like structures, some of them clustered into clusters. In the CMCM + S1P group, the cells showed a special vertical alignment terraced, intercalated disk-like arrangement. Meanwhile, immunocytochemical staining showed that some cells in CMCM group and CMCM + S1P group strongly expressed cardiac-specific antibodies (myocardial myosin heavy chain and striated muscle actin α), indicating that human umbilical cord mesenchymal stem cells in the CMCM Induction can be differentiated into cardiomyocytes. Patch clamp recorded only a rapid upward but no plateau action potentials, as well as a voltage-dependent inward current and a voltage-dependent outward current, in only a subset of cells in the CMCM + S1P group. S1P in promoting human umbilical cord mesenchymal stem cells to cardiac myocyte differentiation and functional integration play a key role.