人羊膜上皮细胞静脉移植治疗大鼠心肌梗死

背景：人羊膜上皮细胞在体外适当诱导条件下可分化为心肌样细胞,可望成为细胞心肌成形术的种子细胞,但在心肌梗死原位是否能分化成心肌细胞值得探讨。目的：探讨人羊膜上皮细胞移植在心肌梗死原位的分化及对心肌梗死后心室重构和心功能的影响。方法：用胰酶消化分离人羊膜上皮细胞,行流式细胞仪检测和免疫组化染色以鉴定其表型特征。结扎SD大鼠左冠状动脉前降支以建立心肌梗死模型,实验分为人羊膜上皮细胞移植组、模型组及假手术组,人羊膜上皮细胞移植组于造模后1周经舌下静脉移植Brdu标记的人羊膜上皮细胞。移植后1,4,6周采用超声心动图检查心功能变化,应用苏木精-伊红和Masson染色观察心肌重构的变化,以免疫荧光双染色法检测人羊膜上皮细胞在心肌梗死区的植活与分化。结果与结论：①所分离的人羊膜上皮细胞表达CD29、CD166、CD73和CK19,不表达CD44、CD34、CD45、CD80、CD86和HLA-DR。②人羊膜上皮细胞移植后6周,心肌梗死区仍可见Brdu标记的阳性细胞,表达心肌特异蛋白连接蛋白43、α-辅肌动蛋白和结蛋白。③移植组大鼠左心室纤维化程度明显低于模型组。④移植组大鼠射血分数、左室短轴缩短率显著高于模型组（P〈0.01）;舒张期左室前壁厚度和收缩期左室前壁厚度也显著大于模型组（P〈0.05）。提示人羊膜上皮细胞在心肌梗死原位可分化为心肌细胞,可减缓心室重构并改善心脏功能。

Intravenous transplantation of human amniotic epithelial cells for treatment of myocardial infarction in rats

BACKGROUND：Human amniotic epithelial cells（hAECs） could differentiate into cardiomyocyte-like cells in vitro and may be candidate cells for cellular cardiomyoplasty.Whether they can differentiate into cardiomyocytes in myocardial infarction is needed to investigate.OBJECTIVE：To observe the survival and differentiation of hAECs post-transplantation in the myocardial infarction（MI） zone,as well as the influence on ventricular remodeling and cardiac function.METHODS：MI models were made by left anterior descending artery ligation in male SD rats（200±20） g,and then divided into hAECs transplanted group（n=12）,model group（n=12） and sham operation group（n=12）.The hAECs were isolated from human amnion using trypsin digestion method,and then its phenotype was identified by flow cytometry and immunohistochemical staining.After 7 days of MI,the BrdU labeled hAECs（0.4 mL,2×10 6 cells） were injected into rats through the sublingual vein.At different times after transplantation,echocardiogram,histopathology,immunohistochemistry and immunofluorescence were performed to observe the survival and differentiation of hAECs in the MI area,as well as the influence on ventricular remodeling and cardiac function.RESULTS AND CONCLUSION：Freshly isolated hAECs highly expressed CD29,CD166,CD73 and CK19.At 6 weeks after hAECs transplantation,cardiac-specific protein connexin-43,α-actinin and desmin positive cells were detected in the MI region of rats.The left ventricular fibrosis was significantly milder in the hAECs transplanted group than in the model group.The left ventricular ejection fraction,left ventricular fractional shortening,left ventricular anterolateral wall thickness at diastole,and left ventricular anterolateral wall thickness at systole were significantly greater in the hAECs transplanted group than in the model group （P 0.01）. hAECs can differentiate into cardiomyocytes in MI area of rats, retard left ventricular remodeling and improve cardiac function, suggesting that hAECs may have the potential for treating clinical MI.