Shear stress-induced apoptosis of adherent neutrophils: a mechanism for persistence of cardiovascular device infections.
Shear stress-induced apoptosis of adherent neutrophils: a mechanism for persistence of cardiovascular device infections.
复制标题
剪切应力诱导的粘附中性粒细胞凋亡：心血管装置感染持续存在的机制。
DOI：
10.1073/pnas.110463197
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发表时间：
2000
影响因子：
11.1
通讯作者：
Anderson,JM
中科院分区：
文献类型：
--
作者：
Shive,MS;Salloum,ML;Anderson,JM
心血管器械相关感染的潜在机制尚不清楚。由于对感染的急性反应的结果在很大程度上取决于中性粒细胞的功能，这些感染的持续性表明，中性粒细胞的功能可能会受到损害，因为细胞对剪切应力的反应。使用旋转盘系统在聚醚聚氨酯脲膜表面产生生理相关剪切应力水平（0-18达因/cm 2; 1达因= 10 μN）。我们证明，剪切应力降低了粘附在心血管器械材料上的中性粒细胞的吞噬能力，并导致与细胞凋亡所述一致的形态学和生化改变。当剪应力水平高于6 dynes/cm 2时，仅在1 h后中性粒细胞就发生了完全凋亡。形态学上，这些细胞显示不可逆的细胞质和核凝聚，同时保持完整的膜。中性粒细胞面积和丝状肌动蛋白含量的分析表明，随着剪切应力水平的增加，细胞面积和肌动蛋白含量同时减少。粘附细菌的中性粒细胞吞噬功能随剪切力的增加而降低。生化改变包括膜磷脂酰丝氨酸暴露和DNA片段化，分别通过原位膜联蛋白V和末端脱氧核苷酸转移酶介导的dUTP末端标记（TUNEL）测定进行评价。剪切应力效应的效力强调了静态条件下粘附中性粒细胞的比较诱导研究。肿瘤坏死因子-α和环己酰亚胺联合应用3 h后未能诱导>21%的细胞凋亡。这些发现表明，剪切应力在心血管器械植入部位细菌感染的发展中起着重要作用。
The mechanisms underlying problematic cardiovascular device-associated infections are not understood. Because the outcome of the acute response to infection is largely dependent on the function of neutrophils, the persistence of these infections suggests that neutrophil function may be compromised because of cellular responses to shear stress. A rotating disk system was used to generate physiologically relevant shear stress levels (0–18 dynes/cm2; 1 dyne = 10 μN) at the surface of a polyetherurethane urea film. We demonstrate that shear stress diminishes phagocytic ability in neutrophils adherent to a cardiovascular device material, and causes morphological and biochemical alterations that are consistent with those described for apoptosis. Complete neutrophil apoptosis occurred at shear stress levels above 6 dynes/cm2after only 1 h. Morphologically, these cells displayed irreversible cytoplasmic and nuclear condensation while maintaining intact membranes. Analysis of neutrophil area and filamentous actin content demonstrated concomitant decreases in both cell area and actin content with increasing levels of shear stress. Neutrophil phagocytosis of adherent bacteria decreased with increasing shear stress. Biochemical alterations included membrane phosphatidylserine exposure and DNA fragmentation, as evaluated byin situannexin V and terminal deoxynucleotidyltransferase-mediated dUTP end labeling (TUNEL) assays, respectively. The potency of the shear-stress effect was emphasized by comparative inductive studies with adherent neutrophils under static conditions. The combination of tumor necrosis factor-α and cycloheximide was ineffective in inducing >21% apoptosis after 3 h. These findings suggest a mechanism through which shear stress plays an important role in the development of bacterial infections at the sites of cardiovascular device implantation.