Mtairag El Mostafa, Houard Xavier, Rais Samira, Pasquier Catherine, Oudghiri Mounia, Jacob Marie-Paule, Meilhac Olivier, Michel Jean-Baptiste
U460 INSERM CHU X, Cardiovascular Remodeling, Paris, France.
Arterioscler Thromb Vasc Biol. 2002 Nov 1;22(11):1824-31. doi: 10.1161/01.atv.0000037102.31086.f4.
Activated polymorphonuclear neutrophils (PMNs) are the main source of circulating neutral endopeptidase (NEP). We tested the hypothesis that NEP inhibition could potentiate the effect of atrial natriuretic peptide (ANP) on PMN-vascular cell interactions in vitro.
ANP alone and its potentiation by retrothiorphan, the NEP inhibitor, significantly inhibited superoxide, lysozyme, and matrix metalloproteinase (MMP)-9 release by N-formyl-Met-Leu-Phe-stimulated PMNs. Activated PMNs degraded exogenous ANP, which was prevented by NEP inhibition. Hypoxia significantly increased the adhesion of PMNs to endothelial cells and their subsequent MMP-9 release by 60% and 150%, respectively (P<0.01). ANP and its potentiation by retrothiorphan limited PMN adhesion to hypoxic endothelial cells and thus decreased their MMP-9 release (P<0.01). Smooth muscle cells (SMCs) incubated with conditioned medium of N-formyl-Met-Leu-Phe-stimulated PMNs exhibited morphological and biochemical changes characteristic of apoptosis (terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling positivity, nuclear condensation/fragmentation, poly ADP-ribose polymerase cleavage, and DNA laddering). SMC detachment and subsequent apoptosis could be related to leukocyte elastase-induced pericellular proteolysis, inasmuch as both events are inhibited by elastase inhibitors. ANP and its potentiation by retrothiorphan were able to limit elastase release, fibronectin degradation, and SMC apoptosis.
ANP potentiation by NEP inhibition could limit PMN activation and its consequences on vascular cells.
活化的多形核中性粒细胞（PMN）是循环中性内肽酶（NEP）的主要来源。我们检验了如下假设，即NEP抑制可增强心房利钠肽（ANP）在体外对PMN与血管细胞相互作用的影响。
单独使用ANP及其与NEP抑制剂雷托噻嗪联合使用，均能显著抑制N-甲酰甲硫氨酰亮氨酰苯丙氨酸（fMLP）刺激的PMN释放超氧化物、溶菌酶和基质金属蛋白酶（MMP）-9。活化的PMN可降解外源性ANP，而NEP抑制可阻止这一过程。缺氧显著增加了PMN与内皮细胞的黏附以及随后MMP-9的释放，分别增加了60%和150%（P<0.01）。ANP及其与雷托噻嗪联合使用可限制PMN与缺氧内皮细胞的黏附，从而减少其MMP-9的释放（P<0.01）。与fMLP刺激的PMN条件培养基一起孵育的平滑肌细胞（SMC）表现出凋亡的形态学和生化特征（末端脱氧核苷酸转移酶介导的dUTP缺口末端标记阳性、核浓缩/碎片化、聚ADP核糖聚合酶裂解和DNA梯状条带）。SMC脱离及随后的凋亡可能与白细胞弹性蛋白酶诱导的细胞周围蛋白水解有关，因为这两个事件均受弹性蛋白酶抑制剂抑制。ANP及其与雷托噻嗪联合使用能够限制弹性蛋白酶释放、纤连蛋白降解和SMC凋亡。
NEP抑制增强ANP作用可限制PMN活化及其对血管细胞的影响。
