Hypoxia increases reepithelialization via an αvβ6-dependent pathway
Hypoxia increases reepithelialization via an αvβ6-dependent pathway
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DOI：
10.1111/j.1067-1927.2005.130206.x
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发表时间：
2005-03-01
影响因子：
2.9
通讯作者：
Darzi, AW
中科院分区：
文献类型：
--
作者：
Ridgway, PF;Ziprin, P;Darzi, AW
上皮再生是皮肤伤口成功愈合的重要步骤。已证明，在该过程中不可或缺的人角质形成细胞在伤口的缺氧愈合边缘具有增加的运动性，这与半封闭缺氧敷料的临床成功相关，尽管对潜在机制仍知之甚少。将亚融合的人角质形成细胞单层暴露于1%缺氧长达24小时或对照条件。进行了长达72小时的复氧研究。流式细胞术检测细胞α v亚基和α v β 6整合素的表达。在低氧暴露后对纤连蛋白进行24小时以上的迁移划痕测定。明胶酶谱法测定基质金属蛋白酶（MMP）-2，9活性，酶联免疫法测定TIMP-1水平。在复氧研究中，α v和α v β 6表达持续增加至48小时（P < 0.001）。标准化划痕实验证实低氧组迁移增加（P < 0.05）。这种作用通过添加α v β 6整联蛋白的特异性抑制剂而减弱。MMP-2和-9活性在低氧暴露后上调（分别为P < 0.001; P < 0.05），而增加的MMP表达被添加α v β 6抑制剂显著延迟（P < 0.05）。特异性明胶酶抑制剂可减弱纤连蛋白上的迁移。我们的结论是，整合素α v β 6依赖性MMP-2和-9上调是缺氧人角质形成细胞迁移增加的一个重要特征。
Reepithelialization is an essential step in successful cutaneous wound healing. Human keratinocytes, integral in this process, have been shown to have increased motility in the hypoxic healing edge of wounds correlating with the clinical success of semiocclusive hypoxic dressings, although the underlying mechanisms remain poorly understood. Subconfluent human keratinocyte cell monolayers were exposed to 1% hypoxia for up to 24 hours or control conditions. Re-oxygenation studies were performed up to 72 hours. Cellular alpha v subunit and alpha v beta 6 integrin expression was measured by flow cytometry. Migration scratch assays on fibronectin following hypoxic exposure were performed over 24 hours. Relative matrix metallo-proteinase (MMP)-2, 9 activity was determined by gelatin zymography with TIMP-1 levels assayed by enzyme-linked immunoassay. Sustained increases in alpha v and alpha v beta 6 expression were shown up to 48 hours in re-oxygenation studies (P < 0.001). Standardized scratch assays confirmed increased migration in the hypoxic group (P < 0.05). This effect was attenuated by the addition of a specific inhibitor of the alpha v beta 6 integrin. MMP-2 and -9 activity was up-regulated following hypoxic exposure (P < 0.001; P < 0.05, respectively), whereas increased MMP expression was significantly retarded by addition of an alpha v beta 6 inhibitor (P < 0.05). Migration on fibronectin was attenuated by a specific gelatinase inhibitor. We conclude that integrin alpha v beta 6-dependent MMP-2 and -9 up-regulation is an important feature of increased migration in hypoxic human keratinocytes.