内皮细胞生长状态对血管平滑肌细胞增生迁移的影响

实验通过建立细胞共培养体系,探讨内皮细胞生长状态对血管平滑肌细胞增生迁移的影响及机制。检测指标包括~3H-TdR掺入、细胞周期、细胞迁移计数和α-SM-actin mRNA表达。结果显示,融合生长内皮使平滑肌细胞~3H-TdR掺入量明显降低,增加平滑肌细胞停留在G_0/G_1期的比例,上调平滑肌细胞α-SM-actin mRNA表达;而对数生长内皮细胞使平滑肌细胞~3H-TdR掺入量明显升高,促进平滑肌细胞由 G_0/G_1期进入G_2/M和S期,下调平滑肌细胞α-SM-actin mRNA表达。对照组平滑肌细胞在基础状态下存在少量迁移,对数增殖内皮细胞组平滑肌迁移数比对照组增高约4倍(P<0.01),而融合生长内皮细胞组平滑肌迁移数仅为对照组的0.5倍(P<0.05)。结果提示内皮细胞生长状态不同,对平滑肌细胞生物学特性的影响也不同,增殖期内皮明显促进平滑肌细胞增生迁移、下调平滑肌细胞α-SM-actin mRNA表达。

Effects of endothelial cell growth states on the proliferation and migration of vascular smooth muscle cells in vitro

Endothelial injury, smooth muscle cells (SMCs) proliferation and migration are the same common pathophysiological processes of many cardiovascular diseases, such as atherosclerosis, hypertension, diabetes and restenosis. It is important to determine the functional interactions between endothelial cells (ECs) and SMCs under pathologic conditions. This work was to study the effects of ECs growth states on the proliferation and migration of vascular SMCs in cell coculture system. 3 HTdR incorporation and flow cytometry were used to determine the effects of ECs growth states on the proliferation of SMCs. The number of migrating SMCs was counted. RT-PCR was used to analyze the expression of α-SM-actin mRNA. The results showed that 3H-TdR incorporation decreased significantly from 14900 ± 1035 cpm/well in the control group to 8575 + 749cpm/well in the confluent ECs group (n=6, P＜0.01), and increased to 27268±2310 cpm/well in the proliferative ECs group (n = 6, P＜0.01). The transition of SMCs from G0/G1 phase to G2/M and S phases was blocked in the confluent ECs group but promoted in the proliferative ECs group. Compared with the control group, the number of migrating cells was about 4 times higher in the proliferative ECs group(n=6, P＜0. 01 ), while it in the confluent ECs group was only the half of the number of the control ( n = 6, P＜ 0. 05 ). The expression of α-SM-actin mRNA was increased significantly in the confluent ECs group(2. 3±0. 11vs 1.4±0. 12,P＜0. 05), but decreased significantly in the proliferative ECs group(0. 92±0. 08 vs 1.4 ± 0.12, P＜ 0.05 ). The results suggest that the biologic features of SMCs are influenced by ECs growth states. The proliferative ECs promote SMCs proliferation, migration and downregulate ot-SM-actin mRNA expression significantly.