Proliferation mechanisms of endothelial cells through crosstalk between endothelial cells and vascular smooth cells

背景：在动物移植模型中，脂质PGE1可显著增强移植静脉的再内皮化，与VSMCs共培养可增强内皮细胞的增殖。然而，PGE1在共培养模型中并不一定能促进内皮细胞的增殖，而PGE1在共培养模型中并没有促进内皮细胞的增殖。我们之前的研究表明，内皮细胞与VSMCs共培养可以促进内皮细胞的增殖。目的：探讨PGE1是否能预防凋亡的ECs死亡。方法：从犬颈静脉中获取ECs和VSMCs， ECs在跨滤共培养系统的下孔中培养，SMCs在跨滤共培养系统的下孔中播种。当内皮细胞融合时，与SMCs一起培养的内皮细胞每天给药50 ng/ml PGE1。采用膜联蛋白V和Hoechst 33342的荧光法和增殖法检测内皮细胞的存活率和凋亡率。在第5天和第7天比较PGE1组和对照组（未给药）的结果。结果：PGEl组与对照组ECs存活率分别为92.1%、76.0%、4.7% （P<0.01）。第5天ECs的凋亡率分别为2.1%、5.1%，第7天的凋亡率分别为1.2%、4.7% （P<0.01）。结论：PGE1可抑制凋亡的ECs死亡，提高ECs存活率。

Background: In an animal implantation model, lipo PGE1 administration brought a significant enhancement of Vein graft reendothelialization, and ECs proliferation was enhanced by coculture wth VSMCs. However, the ECs prohferation was not necessarily enhanced by PGE1 in coculture model, whereas endothelial cells (ECs) proliferation was not enhanced by PGE1 in coculture model Our previous study demonstrated ECs proliferation was enhanced by coculture with VSMCs.Objectives: We investigated whether PGE1 prevented apoptotic ECs death.Methods: ECs and VSMCs were harvested from the canine jugular vein, the ECs were cultured in the lower well of a transfilter coculture system, while SMCs were seeded on a transfilter well. When the ECs became confluent, the ECs cultured with the SMCs with daily administration of 50 ng/ml PGE1. Survival rate and apoptosis rate of ECs were measured by a proliferation assay and a fluolescence method with annexin V and Hoechst 33342. The results were compared between the PGE1 group and Control groups (without PGE1 administration) at day 5 and day 7.Result: Survival rate of ECs in the PGEl group and Control group were 92.1 % and 76.0 % at day 1.2 % and 4.7 % at day 7 (P<0.01). Apoptosis rate of ECs were 2,1% and 5.1 % at day 5, and 1.2 % and 4.7 % at day 7, respectively (P<0.01).Conclusion: The present results suggested that PGE1 inhibits apoptotic ECs death, resulting in improvement of ECs Survival rate.