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

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43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43 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。

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

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.