After a skin injury, keratinocytes switch from a state of homeostasis to one of regeneration leading to the reconstruction of the epidermal barrier. The regulatory mechanism of gene expression underpinning this key switch during human skin wound healing is enigmatic. Long noncoding RNAs (lncRNAs) constitute a new horizon in the understanding of the regulatory programmes encoded in the mammalian genome. By comparing the transcriptome of an acute human wound and skin from the same donor as well as keratinocytes isolated from these paired tissue samples, we generated a list of lncRNAs showing changed expression in keratinocytes during wound repair. Our study focused on HOXC13-AS, a recently evolved human lncRNA specifically expressed in epidermal keratinocytes, and we found that its expression was temporally downregulated during wound healing. In line with its enrichment in suprabasal keratinocytes, HOXC13-AS was found to be increasingly expressed during keratinocyte differentiation, but its expression was reduced by EGFR signalling. After HOXC13-AS knockdown or overexpression in human primary keratinocytes undergoing differentiation induced by cell suspension or calcium treatment and in organotypic epidermis, we found that keratinocyte differentiation was promoted, while the cell inflammatory response was suppressed. Moreover, RNA pull-down assays followed by mass spectrometry and RNA immunoprecipitation analysis revealed that mechanistically HOXC13-AS sequestered the coat complex subunit alpha (COPA) protein and interfered with Golgi-to-endoplasmic reticulum (ER) molecular transport, resulting in ER stress and enhanced keratinocyte differentiation. In summary, we identified HOXC13-AS as a crucial regulator of human epidermal differentiation.

中文翻译：

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人皮肤特异性长链非编码 RNA HOXC13-AS 通过干扰高尔基体逆行转运来调节表皮分化

皮肤损伤后，角质形成细胞从稳态状态转变为再生状态，从而导致表皮屏障的重建。在人类皮肤伤口愈合过程中，支撑这一关键开关的基因表达调控机制是神秘的。长链非编码 RNA (lncRNA) 构成了理解哺乳动物基因组中编码的调控程序的新视野。通过比较来自同一供体的急性人类伤口和皮肤的转录组以及从这些配对组织样本中分离的角质形成细胞，我们生成了一个 lncRNA 列表，显示在伤口修复过程中角质形成细胞中的表达发生了变化。我们的研究集中在 HOXC13-AS，这是一种最近进化的在表皮角质形成细胞中特异性表达的人类 lncRNA，我们发现它的表达在伤口愈合过程中暂时下调。与其在基底层角质形成细胞中的富集一致，HOXC13-AS 被发现在角质形成细胞分化过程中表达增加，但其表达因 EGFR 信号传导而降低。在细胞悬液或钙处理诱导分化的人原代角质形成细胞和器官型表皮中，HOXC13-AS 敲低或过表达后，我们发现角质形成细胞分化得到促进，而细胞炎症反应受到抑制。此外，RNA pull-down 分析以及质谱和 RNA 免疫沉淀分析表明，HOXC13-AS 机械地隔离外壳复合物亚基 α (COPA) 蛋白并干扰高尔基体到内质网 (ER) 的分子转运，导致 ER 应激和增强的角质形成细胞分化。总之，