Functional role of gap junctions in cytokine-induced leukocyte adhesion to endothelium in vivo.
Functional role of gap junctions in cytokine-induced leukocyte adhesion to endothelium in vivo.
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DOI：
10.1152/ajpheart.00266.2008
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发表时间：
2008-07
期刊：
影响因子：
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通讯作者：
Loreto P. Véliz;Francisco G. González;B. Duling;J. Sáez;M. Boric
中科院分区：
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作者：
Loreto P. Véliz;Francisco G. González;B. Duling;J. Sáez;M. Boric
为了评估间隙连接（GJ）参与炎症反应中白细胞-内皮细胞相互作用的假设，我们比较了在存在或不存在GJ阻断剂的情况下，仓鼠颊囊以及野生型（WT）和内皮特异性连接蛋白43（Cx43）缺失小鼠（Cx43 e（-/-））提睾肌中细胞因子刺激引起的白细胞粘附和迁移。在颊囊，局部肿瘤坏死因子-α（TNF-α; 150 ng/ml，15 min）引起粘附于小静脉内皮（LAV）和位于小静脉周围区域（LPV）的白细胞数量持续增加。灌流GJ阻断剂18-α-大黄酸（阿加; 75 μ M）或18-β-大黄酸（50 μ M）可消除TNF-α诱导的LAV和LPV增加;甘珀酸（75 μ M）或油酰胺（100 μ M）可分别使LAV降低50%和75%，LPV降低程度较小。这些GJ阻滞剂均未改变小静脉直径、血流量或白细胞滚动。相比之下，阿加的非GJ阻断剂类似物-有趣的是，当TNF-α刺激后90分钟去除阿加时，LAV开始以与对照相似的速率升高。相反，在TNF-α后90分钟应用阿加减少了先前粘附的细胞的数量。在WT小鼠中，与注射生理盐水的对照组相比，阴囊内注射TNF-α（0.5 μ g/0.3 ml）使LAV（4倍）和LPV（3倍）增加。与WT动物中的观察结果相反，TNF-α刺激不会增加Cx43 e（-/-）小鼠的LAV或LPV。这些结果表明，在体内急性炎症过程中，GJ通信在白细胞粘附和迁移中起重要作用，并进一步表明内皮Cx43在这些过程中起关键作用。
To assess the hypothesis that gap junctions (GJs) participate on leukocyte-endothelium interactions in the inflammatory response, we compared leukocyte adhesion and transmigration elicited by cytokine stimulation in the presence or absence of GJ blockers in the hamster cheek pouch and also in the cremaster muscle of wild-type (WT) and endothelium-specific connexin 43 (Cx43) null mice (Cx43e(-/-)). In the cheek pouch, topical tumor necrosis factor-alpha (TNF-alpha; 150 ng/ml, 15 min) caused a sustained increment in the number of leukocytes adhered to venular endothelium (LAV) and located at perivenular regions (LPV). Superfusion with the GJ blockers 18-alpha-glycyrrhetinic acid (AGA; 75 microM) or 18-beta-glycyrrhetinic acid (50 microM) abolished the TNF-alpha-induced increase in LAV and LPV; carbenoxolone (75 microM) or oleamide (100 microM) reduced LAV by 50 and 75%, respectively, and LPV to a lesser extent. None of these GJ blockers modified venular diameter, blood flow, or leukocyte rolling. In contrast, glycyrrhizin (75 microM), a non-GJ blocker analog of AGA, was devoid of effect. Interestingly, when AGA was removed 90 min after TNF-alpha stimulation, LAV started to rise at a similar rate as in control. Conversely, application of AGA 90 min after TNF-alpha reduced the number of previously adhered cells. In WT mice, intrascrotal injection of TNF-alpha (0.5 microg/0.3 ml) increased LAV (fourfold) and LPV (threefold) compared with saline-injected controls. In contrast to the observations in WT animals, TNF-alpha stimulation did not increase LAV or LPV in Cx43e(-/-) mice. These results demonstrate an important role for GJ communication in leukocyte adhesion and transmigration during acute inflammation in vivo and further suggest that endothelial Cx43 is key in these processes.