大鼠骨髓间质干细胞定向分化的心肌细胞间形成闰盘样结构

Rat bone marrow-derived regenerated cardiomyocytes show intercalated disc-like structure

目的 :建立大鼠骨髓间质干细胞 (BMMSCs)定向分化为心肌细胞的模型 ,了解细胞间藕联情况。方法 :采用贴壁筛选法分离BMMSCs,体外扩增 ,5 -氮胞苷 (5 -aza)定向诱导第 2代BMMSCs分化为心肌细胞 ,取继续培养 1周、2周、3周的细胞进行免疫细胞化学染色 ,鉴定横纹肌肌动蛋白和闰盘样结构的存在。结果 :5 -aza处理后 1周、2周、3周均可见横纹肌肌动蛋白染色阳性细胞。 5 -aza处理后 1周及 2周连结蛋白 4 3在部分细胞上表达 :呈核周散在分布的棕黄色颗粒 ,5 -aza处理后 3周连结蛋白 4 3在细胞密度大的区域呈核周聚集成线形分布的棕黄色颗粒 ,个别细胞间可见此结构 ,类似正常心肌的闰盘结构。结论 :骨髓间质干细胞分化为心肌细胞过程中 ,随培养时间延长及细胞密度增加逐渐形成闰盘样结构。

AIM: To set the model of rat bone marrow me se nchymal stem cells (BMMSCs) that differentiate into cardiomyocytes and observe t he connection structure between cells. METHODS: BMMSCs were isolated by adhering to culture plates and cultured in vitro to expand. Induction of BMMSCs to differentiate into cardi omyo cytes was conducted by treating the cells with 5-aza. Immunocytochemical stainin g was used to identify sarcomeric actin and intercalated disc-like structure wh en the cells were cultured for additional 1 week, 2 or 3 weeks, respectively. RESULTS: Sarcomeric actin positive cells were observed in 1 week , 2 or 3 weeks after 5-aza treatment. Some cells stained positive for connexin4 3 at 1 week and 2 weeks after 5-aza treatment, with brown pellet located disper sively around nucleus. 3 weeks after 5-aza treatment, connexin43 positive cells s howed brown pellet arranging in thready structure around nucleus, such structure could be seen between very few cells which was similar to intercalated disc-lik e structure in normal heart tissue. CONCLUSION: During the process of BMMSCs differentiating into ca rdiomyocytes, intercalated disc-like structure is gradually formed with increas e in culture time and cell density.