Abstract：
Endogenous electric fields (EFs) have been demonstrated to facilitate wound healing by directing the migration of epidermal cells. Despite the identification of numerous molecules and signaling pathways that are crucial for the directional migration of keratinocytes under EFs, the underlying molecular mechanisms remain undefined. Previous studies have indicated that microtubule (MT) acetylation is linked to cell migration, while Paxillin exerts a significant influence on cell motility. Therefore, we postulated that Paxillin could enhance EF-induced directional migration of keratinocytes by modulating MT acetylation. In the present study, we observed that EFs (200 mV/mm) induced migration of human immortalized epidermal cells (HaCaT) towards the anode, while upregulating Paxillin, downregulating HDAC6, and increasing the level of microtubule acetylation. Our findings suggested that Paxillin plays a pivotal role in inhibiting HDAC6-mediated microtubule acetylation during directional migration under EF regulation. Conversely, downregulation of Paxillin decreased microtubule acetylation and electrotaxis of epidermal cells by promoting HDAC6 expression, and this effect could be reversed by the addition of tubacin, an HDAC6-specific inhibitor. Furthermore, we observed that EFs also mediated the polarization of Paxillin and acetylated α-tubulin, which is critical for directional migration. In conclusion, our study revealed that MT acetylation in EF-guided keratinocyte migration is regulated by the Paxillin/HDAC6 signaling pathway, providing a novel theoretical foundation for the molecular mechanism of EF-guided directional migration of keratinocytes.
摘要：
已证明内源性电场（EF）通过指导表皮细胞的迁移来促进伤口愈合。尽管鉴定出许多分子和信号通路对于在EF下角质形成细胞的定向迁移至关重要，潜在的分子机制仍未定义。先前的研究表明，微管（MT）乙酰化与细胞迁移有关，而Paxillin对细胞运动有显着影响。因此,我们推测Paxillin可以通过调节MT乙酰化来增强EF诱导的角质形成细胞的定向迁移。在本研究中,我们观察到EFs（200mV/mm）诱导人永生化表皮细胞（HaCaT）向阳极迁移，在上调Paxillin的同时,下调HDAC6，增加微管乙酰化水平。我们的发现表明，Paxillin在EF调节下的定向迁移过程中在抑制HDAC6介导的微管乙酰化中起关键作用。相反，Paxillin的下调通过促进HDAC6表达来降低表皮细胞的微管乙酰化和电滑行，这种效果可以通过添加tubacin来逆转，HDAC6特异性抑制剂。此外，我们观察到EF还介导了Paxillin和乙酰化α-微管蛋白的极化，这对于定向迁移至关重要。总之,我们的研究表明，在EF引导的角质形成细胞迁移中MT乙酰化受Paxillin/HDAC6信号通路的调节，为EF引导角质形成细胞定向迁移的分子机制提供了新的理论基础。
