骨髓间充质干细胞拮抗氧化型低密度脂蛋白致人脐静脉内皮细胞凋亡

Bone Marrow Mesenchymal Stem Cells Attenuate Endothelial Cell Apoptosis Induced by ox-LDL

目的探讨骨髓间充质干细胞(MSC)对氧化型低密度脂蛋白(ox-LDL)诱导的人脐静脉内皮细胞(HU-VEC)凋亡的影响及有关机制。方法将对数生长期的HUVEC分成三组:对照组单纯培养HUVEC;ox-LDL组的HUVEC给予100 mg/L ox-LDL培养24 h;ox-LDL+MSC组使用细胞培养池共同培养HUVEC和MSC,并加入100mg/L ox-LDL培养24 h。采用流式细胞术检测HUVEC的凋亡情况,采用ELISA检测细胞培养上清液中肿瘤坏死因子α(TNF-α)和血管内皮生长因子(VEGF)的含量,并通过Real-time PCR检测HUVEC中凋亡相关基因Bcl-2与Bax mRNA的表达情况。结果在100 mg/L ox-LDL作用24 h后,细胞凋亡率明显上升,细胞培养上清液中TNF-α、VEGF含量明显上升,Bcl-2 mRNA表达下调,而Bax mRNA表达上调。MSC与HUVEC共培养可增加上清液中VEGF含量,减少TNF-α含量,上调Bcl-2 mRNA表达,下调Bax mRNA表达,使内皮细胞凋亡率明显下降。结论MSC可以拮抗ox-LDL诱导的血管内皮细胞凋亡,可能与其分泌VEGF、抑制炎性反应并上调Bcl-2 mRNA表达及下调Bax mRNA表达有关,为MSC治疗动脉粥样硬化等内皮损伤性疾病进一步提供了理论基础。

Aim To investigate whether bone marrow mesenchymal stem cells （MSC） reduce the apoptosis of human umbilical vein endothelial cells （HUVEC） induced by oxidized low density lipoprotein （ox-LDL） , and related mechanisms. Methods The HUVEC were divided into three groups： HUVEC were cultured in normol medium; HUVEC were cultured with 100 mg/L ox-LDL for 24 h; and HUVEC were cocultured with MSC with 100 mg/L ox-LDL for 24 h. Then cell apoptosis of different groups were mesured by flow cytometry. The content of VEGF, as well as TNF-α, in supernatant medium were determined by ELISA, and Real-time PCR was used to detect Bcl-2 and Bax mRNA expression. Results After 24 h stimulated by ox-LDL, the HUVEC apoptosis rate was increased, and the content of VEGF, TNF-α were significantly increased, while Bcl-2 mRNA expression was downregulated and Bax mRNA upregulated. The MSC cocultured with HUVEC could increase the VEGF levels, reduce TNF-α levels, as well as increase Bcl-2 mRNA expression but reduce the expression of Bax mRNA, HUVEC apoptosis was significantly decreased. Conclusions MSC can at- tenuate HUVEC apoptosis induced by ox-LDL, possibly through the increase of VEGF, reduction of TNF-α, and upregulation of Bcl-2 mRNA and downregulation of Bax mRNA, which provides a theoretical basis for MSC as a treatment for endothelial injury disease such as atherosclerosis.