内皮屏障功能的丧失需要中性粒细胞黏附。

Loss of endothelial barrier function requires neutrophil adhesion.

作者信息

Marcus B C, Hynes K L, Gewertz B L

机构信息

Department of Surgery, University of Chicago, Pritzker School of Medicine, IL 60637, USA.

出版信息

Surgery. 1997 Aug;122(2):420-6; discussion 426-7. doi: 10.1016/s0039-6060(97)90035-0.

DOI:10.1016/s0039-6060(97)90035-0

PMID:9288149

Abstract

BACKGROUND

The inflammatory response is characterized by cytokine-induced up-regulation of endothelial adhesion molecules followed by polymorphonuclear neutrophil (PMN) adhesion and breakdown of tight junctions between cells. The purpose of this investigation was to determine whether PMN adhesion is an essential element in the alteration of endothelial permeability or whether cytokines alone can produce this change.

METHODS

Human umbilical vein endothelial cells (HUVECs) were exposed to formylated met-leu-phe-activated PMNs. In a second series of experiments, PMNs were contained in a microporous membrane that allowed passage of secreted cytokines but not cells. Permeability was quantified by using transendothelial electrical resistance (TEER, ohm.cm2,) whereas expressions of two cell adhesion molecules (endothelial leukocyte adhesion molecule-1 [ELAM-1] and intercellular adhesion molecule-1 [ICAM-1]) were measured by flow cytometry (% shift). Cytokine production was monitored with enzyme-linked immunosorbant assays (picograms per milliliter).

RESULTS

Stimulated PMNs secreted comparable amounts of cytokines whether allowed access to HUVECs or trapped in a microporous membrane (interleukin-1 alpha, 5.88 +/- 2.38 versus 3.65 +/- 1.84 pg/ml; tumor necrosis factor-alpha, 10.27 +/- 3.21 versus 6.61 +/- 1.82 pg/ml). Up-regulation of ELAM-1 and ICAM-1 was observed whether PMNs were free or restricted (52.97% +/- 2.14% versus 75.32% +/- 4.19% and 71.66% +/- 7.37% versus 73.66% +/- 4.32%, respectively). TEER was unchanged in controls and when PMNs were membrane restricted. In contrast, TEER decreased precipitously (51% +/- 5.9% of control, p < 0.05) if PMNs were allowed access to HUVECs.

CONCLUSIONS

Cytokine secretion by PMNs is independent of endothelial contact and is sufficient to upregulate adhesion molecules. However, PMN adhesion is essential for the loss of endothelial barrier function, which leads to diapedesis of activated PMNs and eventual tissue injury.

摘要

背景

炎症反应的特征是细胞因子诱导内皮黏附分子上调，随后多形核中性粒细胞（PMN）黏附以及细胞间紧密连接破坏。本研究的目的是确定PMN黏附是否是内皮通透性改变的关键因素，或者单独的细胞因子是否就能产生这种变化。

方法

将人脐静脉内皮细胞（HUVECs）暴露于甲酰化甲硫氨酰-亮氨酰-苯丙氨酸激活的PMN。在另一系列实验中，将PMN置于微孔膜中，该膜允许分泌的细胞因子通过，但不允许细胞通过。通过跨内皮电阻（TEER，欧姆·平方厘米）定量通透性，而通过流式细胞术（%变化）测量两种细胞黏附分子（内皮白细胞黏附分子-1 [ELAM-1]和细胞间黏附分子-1 [ICAM-1]）的表达。用酶联免疫吸附测定法（皮克/毫升）监测细胞因子的产生。

结果

无论PMN是能够接触HUVECs还是被困在微孔膜中，受刺激的PMN分泌的细胞因子量相当（白细胞介素-1α，5.88±2.38对3.65±1.84皮克/毫升；肿瘤坏死因子-α，10.27±3.21对6.61±1.82皮克/毫升）。无论PMN是自由的还是受限的，均观察到ELAM-1和ICAM-1上调（分别为52.97%±2.14%对75.32%±4.19%和71.66%±7.37%对73.66%±4.32%）。在对照组以及PMN被膜限制时，TEER无变化。相反，如果PMN能够接触HUVECs，TEER则急剧下降（为对照组的51%±5.9%，p<0.05）。