Díaz-González F, González-Alvaro I, Campanero M R, Mollinedo F, del Pozo M A, Muñoz C, Pivel J P, Sánchez-Madrid F
Section of Rheumatology, Hospital de la Princesa, Universidad Autónoma de Madrid, Spain.
J Clin Invest. 1995 Apr;95(4):1756-65. doi: 10.1172/JCI117853.
The activation of the endothelial cells by extravascular stimuli is the key event in the extravasation of circulating leukocytes to target tissues. L-selectin, a member of the selectin family, is constitutively expressed by white cells, and is the molecule involved in the initial binding of leukocytes to activated endothelium. After activation, leukocytes rapidly release L-selectin from the cell surface, suggesting that the functional activity of this molecule is controlled in large part by its appearance and disappearance from cell surface. We have studied in a neutrophil-activated endothelial cell binding assay, the effect of different antiinflammatory drugs (steroidal and nonsteroidal) in the L-selectin-mediated interaction of neutrophils with activated endothelial cells. Some nonsteroidal antiinflammatory drugs (NSAIDs), such as indomethacin, diclofenac, ketoprofen, and aspirin, but not steroids, strongly inhibited the neutrophil-endothelial cell attachment. Furthermore, we also investigated the underlying mechanism of this functional effect. The expression of L-selectin on the neutrophil surface rapidly decreased in the presence of different NSAIDs, in a dose- and time-dependent manner, whereas no changes in the expression of other adhesion molecules such as CD11a, CD11b, CD31, or ICAM-3 (CD50) were observed. Interestingly, studies in vivo on healthy volunteers treated with physiological doses of indomethacin showed a significant decrease of L-selectin neutrophil expression. Only diclofenac induced an upregulation of CD11b expression, suggesting an activating effect on neutrophils. No enzyme release was observed upon treatment of neutrophils with different NSAIDs, indicating a lack of degranulatory activity of NSAIDs, with the exception of diclofenac. The downregulation of L-selectin expression was due to the rapid cleavage and shedding of the membrane L-selectin, as determined by both immunoprecipitation from 125I-labeled neutrophils, and quantitative estimation in cell-free supernatants. These results suggest that NSAIDs exert a specific action on adhesion receptor expression in neutrophils, which might account, at least in part, for the antiinflammatory activities of NSAIDs.
血管外刺激激活内皮细胞是循环白细胞外渗至靶组织的关键事件。L-选择素是选择素家族的一员，由白细胞组成性表达，是参与白细胞与活化内皮细胞初始结合的分子。激活后，白细胞迅速从细胞表面释放L-选择素，这表明该分子的功能活性在很大程度上受其在细胞表面出现和消失的控制。我们在中性粒细胞激活的内皮细胞结合试验中研究了不同抗炎药物（甾体和非甾体）对L-选择素介导的中性粒细胞与活化内皮细胞相互作用的影响。一些非甾体抗炎药（NSAIDs），如吲哚美辛、双氯芬酸、酮洛芬和阿司匹林，但甾体类药物则不然，强烈抑制中性粒细胞与内皮细胞的黏附。此外，我们还研究了这种功能效应的潜在机制。在不同NSAIDs存在下，中性粒细胞表面L-选择素的表达以剂量和时间依赖性方式迅速降低，而未观察到其他黏附分子如CD11a、CD11b、CD31或ICAM-3（CD50）表达的变化。有趣的是，对用生理剂量吲哚美辛治疗的健康志愿者进行的体内研究表明，L-选择素在中性粒细胞上的表达显著降低。只有双氯芬酸诱导CD11b表达上调，表明对中性粒细胞有激活作用。用不同NSAIDs处理中性粒细胞后未观察到酶释放，表明NSAIDs缺乏脱颗粒活性，但双氯芬酸除外。L-选择素表达的下调是由于膜L-选择素的快速裂解和脱落，这通过对125I标记的中性粒细胞进行免疫沉淀以及对无细胞上清液进行定量评估来确定。这些结果表明，NSAIDs对中性粒细胞黏附受体表达具有特异性作用，这可能至少部分解释了NSAIDs的抗炎活性。
