关键词: 冠状动脉内皮细胞, 自噬, 缺氧, 骨髓间充质干细胞, 共培养, 凋亡

Abstract:

Objective To investigate whether mesenchymal stem cells lead to induction of autophagy and change at early apoptotic rate under hypoxia condition on coronary artery endothelial cells. Methods We constructed the co?culture model of HCAECs（human coronary artery endothelial cells） and hBMMSCs（human bone marrow?derived mesenchymal stem cells）. In experiment group，HCAEC co?cultured with MSC，HCAEC cultured alone in blank group. And in control group ，HCAEC cultured alone using same medium with experiment group. Each group separately cultured 24 h under nomoxia （5% CO2 ，95% air）and hypoxia（1% O2 ，5% CO2 ，94% N2）condition. The HCAEC′s expression of LC3 and Beclin?1 at mRNA and protein level was detected by Real?Time PCR and Western blotting ， respectively. Flow cytometry was used to detect early apoptotic rate. Results The protein expression of LC3 and Beclin?1 in co?culture groups and hypoxia groups significantly higher than separate culture groups and nomoxia groups respectively（P<0.05），while mRNA expression of LC3 and Beclin?1 in each group shows no difference （P>0.05）. The early apoptotic rate of co?culture group under hypoxia was 8.86%±1.48%，which was significantly lower than those in separate culture group under hypoxia and control group under hypoxia（15.23%±2.56% and 14.49%±3.31% ，P<0.05）. Conclusion MSC induces autophagy in HCAEC，along with decrease of early apoptosis rate of HCAEC under hypoxia condition.

Key words: apoptosis, autophagy, bone marrow?derived mesenchymal stem cells , hypoxia, human coronary artery endothelial cells, co?culture