Background Due to vasculature injury and increased oxygen consumption, the early wound microenvironment is typically in a hypoxic state. We observed enhanced cell migration ability under early short-term hypoxia. CCL2 belongs to the CC chemokine family and was found to be increased in early hypoxic wounds and enriched in the extracellular signal-regulated kinase (ERK)1/2 pathway in our previous study. However, the underlying mechanism through which the CCL2-ERK1/2 pathway regulates wound healing under early short-term hypoxia remains unclear. Activation of epithelial-mesenchymal transition (EMT) is a key process in cancer cell metastasis, during which epithelial cells acquire the characteristics of mesenchymal cells and enhance cell motility and migration ability. However, the relationship between epithelial cell migration and EMT under early short-term hypoxia has yet to be explored. Methods HaCaT cells were cultured to verify the effect of early short-term hypoxia on migration through cell scratch assays. Lentiviruses with silenced or overexpressed CCL2 were used to explore the relationship between CCL2 and migration under short-term hypoxia. An acute full-thickness cutaneous wound rat model was established with the application of an ERK inhibitor to reveal the hidden role of the ERK1/2 pathway in the early stage of wound healing. The EMT process was verified in all the above experiments through western blotting. Results In our study, we found that short-term hypoxia promoted cell migration. Mechanistically, hypoxia promoted cell migration through mediating CCL2. Overexpression of CCL2 via lentivirus promoted cell migration, while silencing CCL2 via lentivirus inhibited cell migration and the production of related downstream proteins. In addition, we found that CCL2 was enriched in the ERK1/2 pathway, and the application of an ERK inhibitor in vivo and in vitro verified the upstream and downstream relationships between the CCL2 pathway and ERK1/2. Western blot results both in vivo and in vitro demonstrated that early short-term hypoxia promotes epidermal cell migration by activating the CCL2-ERK1/2 pathway and EMT during wound healing. Conclusions Our work demonstrated that hypoxia in the early stage serves as a stimulus for triggering wound healing through activating the CCL2-ERK1/2 pathway and EMT, which promote epidermal cell migration and accelerate wound closure. These findings provide additional detailed insights into the mechanism of wound healing and new targets for clinical treatment.

中文翻译：

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早期短期缺氧通过激活伤口愈合过程中的CCL2-ERK1/2通路和上皮间质转化来促进表皮细胞迁移。


背景由于脉管系统损伤和耗氧量增加，早期伤口微环境通常处于缺氧状态。我们观察到早期短期缺氧下细胞迁移能力增强。 CCL2属于CC趋化因子家族，在我们前期的研究中发现其在早期缺氧伤口中增加，并在细胞外信号调节激酶（ERK）1/2通路中富集。然而，CCL2-ERK1/2 通路在早期短期缺氧下调节伤口愈合的潜在机制仍不清楚。上皮间质转化（EMT）的激活是癌细胞转移的关键过程，在此过程中上皮细胞获得间质细胞的特性并增强细胞的运动和迁移能力。然而，早期短期缺氧下上皮细胞迁移与EMT之间的关系仍有待探讨。方法培养HaCaT细胞，通过细胞划痕实验验证早期短期缺氧对迁移的影响。使用沉默或过表达CCL2的慢病毒来探讨CCL2与短期缺氧下迁移的关系。应用ERK抑制剂建立急性全层皮肤伤口大鼠模型，揭示ERK1/2通路在伤口愈合早期的隐藏作用。上述所有实验均通过蛋白质印迹法验证了 EMT 过程。结果在我们的研究中，我们发现短期缺氧促进细胞迁移。从机制上讲，缺氧通过介导 CCL2 促进细胞迁移。通过慢病毒过度表达CCL2促进细胞迁移，而通过慢病毒沉默CCL2则抑制细胞迁移和相关下游蛋白的产生。 此外，我们发现CCL2在ERK1/2通路中富集，并且ERK抑制剂在体内和体外的应用验证了CCL2通路与ERK1/2之间的上下游关系。体内和体外Western blot结果表明，早期短期缺氧在伤口愈合过程中通过激活CCL2-ERK1/2通路和EMT来促进表皮细胞迁移。结论 我们的工作表明，早期缺氧通过激活 CCL2-ERK1/2 通路和 EMT 来触发伤口愈合，从而促进表皮细胞迁移并加速伤口闭合。这些发现为伤口愈合机制和临床治疗的新目标提供了更多详细的见解。