血管紧张素Ⅱ1型受体自身抗体致血管内皮炎性损伤的研究

Autoantibody against angiotensin H type 1 receptor （AT1-AA） induced inflammatory injury in vascular endothelium

目的观察血管紧张素Ⅱ1型受体（AT1R）自身抗体（AT1-AA）长期作用下大鼠血管内皮是否会发生炎性损伤。方法以人工合成的人AT1R的细胞外第二环功能表位肽段（AT1R—ECⅡ）为抗原，主动免疫雌性Wistar大鼠9个月，建立AT广AA阳性的大鼠模型。血细胞涂片法检测大鼠血中血细胞变化情况，以激光共聚焦法检测大鼠血管内皮细胞细胞间黏附分子-1（ICAM-1）的表达，以免疫组化法检测血管内皮细胞血管细胞间黏附分子-1（VCAM-1）的表达。结果主动免疫的Wistar大鼠（n=9）血清中产生了高滴度的IgG类AT1-AA，从免疫2个月开始直到免疫结束，抗体维持在较恒定的高水平[免疫9个月时光密度值与同期溶剂对照组比较，（1．79±0．26）比（0．43±0．15），P〈0．01]。免疫结束时，同溶剂对照组相比，大鼠血中自细胞数目有升高趋势，血小板数量显著下降，而血红蛋白含量未变。大鼠胸主动脉内皮细胞ICAM-1[荧光值（2．97±0．50）比（1．63±0．48），P〈0．05]和VCAM-1[平均光密度值M00（O．27±0．04）比（0．17±0．04），P〈0．05]表达均显著上调。结论AT1-AA长期刺激可引起大鼠血管内皮细胞发生炎性损伤。

Objective To investigate whether autoantibody against angiotensinⅡ type 1 receptor （ATI- AA ） can induce inflammatory injury in vascular endothelium. Methods To establish AT1AA-positive rat models, health adult female Wistar rats were actively immunized with the synthetic peptide corresponding to the sequences for the second extracellular loop of human angiotensin Ⅱ type 1 receptor （AT1R-EC n ） for nine months. Blood cell smear was used to detect the changes of blood cells in rats. Confocal was used to observe the expression of intercellular adhesion molecule-1 （ICAM-1） and immunohistoehemieal method was used to determine the level of vascular cellular adhesion molecule-1 （VCAM-1） in vascular endothelial cells. Results The ELISA detection showed that high titer of IgG isotype ATI-AA appeared in rats actively immunized with ATIR-ECⅡ. From the second month after the primary immune to the end of the experiment, the titer of ATI-AA maintained at a constant high level （optical density value at 9 month is 1.79±0.26 vs 0.43±0.15, P〈0.01, vs vehicle group）. At 9 month, compared with the vehicle group, the number of leukocytes in immunized group rats tended to increase, but the platelet number was significantly decreased. In additional, both of the expressions of ICAM-1 （fluorescence, 2.97±- 0.50 vs 1.63±0.48, P〈0.05） and VCAM-1 （mean optical density, 0.27±-0.04 vs 0.17±-0.04, P〈0.05） were markedly increased in vascular endothelium. However, there was no significant difference with the haemoglobin concentration between the two groups. Conclusion The 10ng-term stimulation with AT1-AA can induce inflamma- tory injury in vascular endothelium in rats.