人脐带间充质干细胞分泌物对肝细胞增殖和凋亡的影响

目的 探讨人脐带间充质干细胞(human umbilical cord mesenchymal stem cells,HUC MSC)旁分泌物质在体外对肝细胞再生和凋亡的影响.方法 利用Ⅳ型胶原酶和胰酶消化法从脐带中分离间充质干细胞,制备含有HUCMSC旁分泌物质的条件培养基(mesenchymal stem cells-conditioned medium,MSC-CM),采用低浓度胶原酶原位循环灌流法分离肝细胞.试验分为对照组、2%MSC-CM组和8%MSC-CM组三组.采用MTT比色法观察不同浓度MSC-CM对正常肝细胞增殖的影响.测定上清中尿素、白蛋白的含量,观察不同浓度MSC-CM对肝细胞功能的影响.利用放线菌素D和肿瘤坏死因子α诱导肝细胞凋亡,采用细胞活性分析试剂盒检测不同浓度MSC-CM对肝细胞凋亡的影响.结果 与对照组比较,2%MSC-CM组吸光度(A)540nm值(P＜0.01)以及上清尿素和白蛋白含量显著升高(P＜0.01),肝细胞存活率增加(P＜0.05);8%MSC-CM组与对照组无显著差异.结论 低浓度的MSC-CM在体外可以刺激正常肝细胞再生,抑制受损肝细胞凋亡,改善肝细胞功能.

Effect of human umbilical cord mesenchymal stem cell-secretion on proliferation and apoptosis in hepatocytes

Objective To investigate the effect of human umbilical cord mesenchymal stem cell paracrine substance on proliferation and apoptosis of liver cells in vitro. Methods Mesenchymal stem cells (MSC)were separated from human umbilical cord with type Ⅳ collagenase and trypsogen digestion method and cultured in vitro. The human umbilical cord mesenchymal stem cells-conditioned medium(MSC-CM) which contain paracrine substance of human umbilical cord mesenchymal stem cells (HUCMSC) was prepared. Hepatocytes were isolated from SD rats by low concentration collagenase perfusion procedure. There were three groups in the experiment, control group, 2% MSC-CM group and 8% MSC-CM group. The proliferation of normal hepatocytes were assayed with MTT method. We detected the urea and albumin level in culture supernatant to assay the hepatocyte function under different concentration MSC-CM. Hepatocytes were induced for apoptosis by Actinomycin D and tumor necrosis factor alpha (TNF-α),and the apoptosis effect of different concentration MSC-CM was assayed with LIVE/DEAD Viability/Cytotoxicity Kit. Results The MTT assay showed that the absorbance of 2% MSC-CM group was significantly increased (P＜0. 01), and the urea and albumin levels of 2 % MSC-CM group were also significantly increased when compared with control group(P＜0. 01).LIVE/DEAD Viability/Cytotoxicity Kit revealed that hepatocyte survival rate of 2 % MSC-CM group was increased when compared with control group(P＜0. 05), there were no significant differences in above-mentioned experiments when 8% MSC-CM group compared with control group. Conclusion The low concentration MSC-CM could stimulate normal hepatocyte proliferation, inhibit impaired hepatocyte apoptosis and improve hepatocyte function.