Lindemann Stephan, Gierer Claudia, Darius Harald
Department of Medicine II, Johannes Gutenberg-University, Langenbeckstr. 1, D-55101 Mainz, Germany.
Basic Res Cardiol. 2003 Feb;98(1):8-15. doi: 10.1007/s00395-003-0383-1.
Prostacyclin is an important endothelial mediator involved in the interaction of neutrophils (PMN) with the vessel wall. Many studies have shown the beneficial effects of prostacyclin in ischemia and reperfusion. However, no previous study has investigated the direct effects of the prostacyclin analogs iloprost (ILO) and alprostadil (PGE(1)) on the endothelial part of the adhesion process. Human umbilical vein endothelial cells (HUVECs) were grown to confluence, stimulated with 300 U/ml TNF-alpha and treated with increasing concentrations of ILO and PGE(1). The cells were washed to remove TNF and the inhibitors and adhesion of fluorescence-green labeled PMN was determined microscopically. ICAM-1, VCAM-1 and E-selectin expression were measured by a cell-surface ELISA. The chemoattractant activity of the endothelial cell releasate was tested in a Boyden chamber.ILO and PGE(1) reduced PMN-adhesion in a concentration-dependent manner (ILO: -54 +/- 9 % at 0.5 microM, PGE1: -46 +/- 10 % at 10 microM). However, the surface expression of ICAM-1, VCAM-1 and E-selectin remained unaltered. When the supernatant of iloprost/PGE(1)-treated cells was transferred onto cells that were activated, but not treated with ILO or PGE(1), the reduction of PMN adhesion remains sustained. These data indicate that the inhibitory effect of ILO/ PGE(1) treatment is achieved by a reduced chemoattractant potential. PAF-antagonists were able to block neutrophil adhesion and mimicked the effect of ILO, while exogenous PAF diminished the inhibitory effect of ILO concentration-dependently. This study demonstrates the beneficial effects of ILO and PGE(1) on inflammatorily activated endothelial cells. These prostacyclin analogs inhibit PMN-adhesion despite maximal adhesion molecule expression by regulating the balance of - yet to be determined - endothelial-derived mediators.
前列环素是一种重要的内皮介质，参与中性粒细胞（PMN）与血管壁的相互作用。许多研究表明前列环素在缺血和再灌注中具有有益作用。然而，此前尚无研究调查前列环素类似物伊洛前列素（ILO）和前列地尔（PGE₁）对黏附过程中内皮部分的直接影响。将人脐静脉内皮细胞（HUVECs）培养至汇合状态，用300 U/ml肿瘤坏死因子-α（TNF-α）刺激，并用浓度递增的ILO和PGE₁处理。洗涤细胞以去除TNF和抑制剂，通过显微镜测定荧光绿色标记的PMN的黏附情况。通过细胞表面酶联免疫吸附测定法测量细胞间黏附分子-1（ICAM-1）、血管细胞黏附分子-1（VCAM-1）和E-选择素的表达。在内皮细胞释放物的趋化活性在博伊登小室中进行测试。ILO和PGE₁以浓度依赖性方式降低PMN黏附（ILO：在0.5 μM时降低54±9%，PGE₁：在10 μM时降低46±10%）。然而，ICAM-1、VCAM-1和E-选择素的表面表达保持不变。当将伊洛前列素/PGE₁处理细胞的上清液转移到被激活但未用ILO或PGE₁处理的细胞上时，PMN黏附的降低仍然持续。这些数据表明ILO/PGE₁处理的抑制作用是通过降低趋化活性实现的。血小板活化因子（PAF）拮抗剂能够阻断中性粒细胞黏附并模拟ILO的作用，而外源性PAF则浓度依赖性地减弱ILO的抑制作用。本研究证明了ILO和PGE₁对炎症激活的内皮细胞具有有益作用。这些前列环素类似物尽管黏附分子表达达到最大，但通过调节尚未确定的内皮衍生介质的平衡来抑制PMN黏附。
