主要组织相容性复合体-Ⅰ类相关链A抗原刺激内皮细胞增殖及其分泌功能的变化

Major histocompatibility complex class Ⅰ-related chain A antigens stimulate endothelial cells proliferation and cause changes of their secreting functions

目的 观察主要组织相容性复合体-Ⅰ类相关链A（MICA）抗原对血管内皮细胞的影响及其分泌功能变化.方法 将MICA抗原分5、10、25 μg/L 3个剂量加入培养基中作为实验组,加入等体积的磷酸盐缓冲液（PBS）作为对照组,对血管内皮细胞予以培养.采用噻唑蓝（MTT）比色法检测细胞增殖,并测定细胞上清液中前列环素代谢产物6-酮-前列腺素F1α（6-keto-PGF1α）、内皮素（ET-1）、组织型纤溶酶原激活物（t-PA）及其抑制物（PAI）和可溶性MICA（sMICA）的水平.结果 各实验组（A5、A10、A25）内皮细胞A570值均高于对照组（A0）.以A5组增殖最为明显,A10组比A5组稍下降,但明显高于A25组,差异有统计学意义（P＜0.05）.在相同剂量下48 h时增殖率最高,A570值分别为0.458、0.446、0.389.72 h和96 h呈持续缓慢增殖,差异有统计学意义（P＜0.05）.A10、A25组细胞上清中的6-keto-PGF1α水平分别为144.6、132.8 ng/L,A0、A5组分别为226.5、232.6 ng/L A10、A25组ET-1水平分别为23.6、25.8 ng/L,A0、A5组分别为11.8、10.4 ng/L.A10、A25组和A0、A5组比较,差异均有统计学意义（P＜0.05）.各实验组t-PA、PAI、sMICA分别为161.2、154.2、157.8μg/L 221.6、248.5、252.4μg/L 35.8、27.4、21.8 ng/L,而对照组分别为233.5μg/L、137.8μgL、352.5 ng/L.实验组和对照组之间比较,差异均有统计学意义（P＜0.05）.结论 MICA抗原能刺激内皮细胞增殖,以小剂量诱导增殖明显,并呈持续缓慢增殖.同时能够引起内皮细胞功能受损,凝血功能增强,而纤溶功能下降,sMICA水平下降.

Objective To investigate the impact of major histocompatibility complex class Ⅰ -related chain A （MICA） antigen against endothelial cells and changes of secreting functions. Methods The endothelial cells were divided into three experimental groups （A5, A10, A25）, which were stimulated with exogenous recombinant MICA antigen at 5, 10 and 25 μg/L respectively. Group A0 was added equivalent volume of PBS as control. The proliferation of endothelial cells was measured by MTF assay. The levels of metabolic product of PGI2 （6-keto-PGF1α）, endothelin （ET-1）, tissue plasminogen activator （t-PA） and its inhibitor （PAI） and soluble MICA （sMICA） in the supernatant of all groups were determined. Results A570 values in all experimental groups were higher than in control group. A570 values in both As and A10 groups were significantly higher than in control group and A25 group （ P 〈 0. 05 ）, but there were no significant differences between A5 and A10 groups （P 〉 0. 05 ）. The proliferation rate of 48 h was the highest in identical dosage. A570 of 48 h was 0. 458, 0. 446 and 0. 389 in A5, A10, A25 respectively. The proliferation rate at 72 h and 96 h was persistently decreased over time. There were significant differences （P 〈0. 05）.The level of 6-keto-PGF1α in groups A10, A25 was 144. 6 and 132. 8 ng/L, which was lower than in group A0 （226. 5 ng/L） and A5 （232. 6 ng/L）. The level of ET-1 in groups A10, A25 was 23. 6 and 25.8 ng/L,and that in group A0, A5 was 11. 8 and 10. 4 ng/L, respectively. The difference was statistically significant （P 〈 0. 05）. The level of t-PA in experimental groups were 161.2, 154. 2 and 157. 8 μg/L, and the level of PAI was 221.6, 248.5 and 252. 4 μg/L, respectively. sMICA in three experimental groups was 35.8,27. 4 and 21.8 ng/L respectively, which was lower than that in control group （352. 5 ng/L）. There were significant differences between experimental groups and control group （ P 〈 0. 05 ）. Conclusion The small dosage of MICA antigen can stimulate endothelial cell persistent proliferation. Meanwhile, MICA antigen can cause the injury of endothelial cells and induce the enhanced coagulation function, the declined fibrinolytic function and the decreased level of sMICA.