Department of Otolaryngology-Head and Neck Surgery, Key Laboratory, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.
Department of Biochemistry & Molecular Biology, Shanxi Medical University, Taiyuan, China.
Cell Prolif. 2019 Sep;52(5):e12638. doi: 10.1111/cpr.12638. Epub 2019 May 31.
Terminally differentiated stratified squamous epithelial cells play an important role in barrier protection of the skin. The integrity of epidermal cells is maintained by tight regulation of proliferation and differentiation. The aim of this study was to investigate the role of epigenetic regulator H3K4me3 and its demethylase Jarid1b in the control of epithelial cell differentiation.
RT-qPCR, Western blotting and IHC were used to detect mRNA and protein levels. We analysed cell proliferation by CCK8 assay and cell migration by wound healing assay. ChIP was used to measure H3K4me3 enrichment. A chamber graft model was established for epidermal development.
Our studies showed that H3K4me3 was decreased during epidermal differentiation. The H3K4me3 demethylase Jarid1b positively controlled epidermal cell differentiation in vitro and in vivo. Mechanistically, we found that Jarid1b substantially increased the expression of mesenchymal-epithelial transition (MET)-related genes, among which Ovol1 positively regulated differentiation gene expression. In addition, Ovol1 expression was repressed by PI3K-AKT pathway inhibitors and overexpression (O/E) of the PI3K-AKT pathway suppressor Ship1. Knockdown (KD) of Ship1 activated downstream PI3K-AKT pathway and enhanced Ovol1 expression in HaCaT. Importantly, we found that Jarid1b negatively regulated Ship1 expression, but not that of Pten, by directly binding to its promoter to modulate H3K4me3 enrichment.
Our results identify an essential role of Jarid1b in the regulation of the Ship1/AKT/Ovol1 pathway to promote epithelial cell differentiation.
终末分化的复层鳞状上皮细胞在皮肤屏障保护中发挥重要作用。表皮细胞的完整性通过增殖和分化的紧密调节来维持。本研究旨在探讨表观遗传调节因子 H3K4me3 及其去甲基化酶 Jarid1b 在控制上皮细胞分化中的作用。
采用 RT-qPCR、Western blot 和 IHC 检测 mRNA 和蛋白水平。我们通过 CCK8 检测法分析细胞增殖，通过划痕愈合实验分析细胞迁移。采用 ChIP 检测 H3K4me3 富集。建立表皮发育腔室移植模型。
我们的研究表明，H3K4me3 在表皮分化过程中减少。H3K4me3 去甲基化酶 Jarid1b 正向调控体外和体内表皮细胞分化。机制上，我们发现 Jarid1b 显著增加了上皮-间充质转化（MET）相关基因的表达，其中 Ovol1 正向调控分化基因的表达。此外，PI3K-AKT 通路抑制剂和 PI3K-AKT 通路抑制剂过表达（O/E）抑制了 Ovol1 的表达。SHIP1。SHIP1 的敲低（KD）激活下游 PI3K-AKT 通路，并增强 HaCaT 中的 Ovol1 表达。重要的是，我们发现 Jarid1b 通过直接结合其启动子来调节 H3K4me3 富集，从而负调控 Ship1 表达，但不调控 Pten 表达。
我们的结果确定了 Jarid1b 在调节 Ship1/AKT/Ovol1 通路以促进上皮细胞分化中的重要作用。
