Human dental pulp cells (hDPCs) possess the capacity to differentiate into odontoblast-like cells in response to exogenous stimuli. Histone methylation is one of the most robust epigenetic marks and is essential for the regulation of multiple cellular processes. Previous studies have shown that histone methyltransferases (HMTs) and histone demethylases (HDMs) are crucial for the osteogenic differentiation of human bone marrow, adipose tissue, and tooth tissue. However, little is known about the role of histone methylation in hDPC differentiation. Here, the expression levels of HMTs and HDMs were profiled in hDPCs undergoing odontogenic induction. Among several differentially expressed enzymes, HDM KDM5A demonstrated significantly enhanced expression during cytodifferentiation. Furthermore, KDM5A expression increased during early passages and in a time-dependent manner during odontogenic induction. Using a shRNA-expressing lentivirus, KDM5A was knocked down in hDPCs. KDM5A depletion resulted in greater alkaline phosphatase activity and more mineral deposition formation. Meanwhile, the expression levels of the odontogenic markers DMP1, DSPP, OSX, and OCN were increased by KDM5A knockdown. As a histone demethylase specific for tri- and dimethylated histone H3 at lysine 4 (H3K4me3/me2), KDM5A deficiency led to a significant increment in total H3K4me3 levels, whereas no significant difference was found for H3K4 me2. H3K4me3 levels on the promoters of the odontogenic markers increased after KDM5A knockdown in hDPCs. These results demonstrated that KDM5A is present in hDPCs and inhibits the odontogenic differentiation potentiality of hDPCs by removing H3K4me3 from specific gene promoters, suggesting that KDM5A-dependent histone demethylation may play an important role in reparative dentinogenesis.

中文翻译：

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组蛋白去甲基化酶KDM5A对人牙髓细胞牙源性分化的影响。


人牙髓细胞（hDPC）具有响应外源刺激而分化成成牙本质细胞样细胞的能力。组蛋白甲基化是最强大的表观遗传标记之一，对于多种细胞过程的调节至关重要。先前的研究表明，组蛋白甲基转移酶（HMT）和组蛋白去甲基酶（HDM）对于人类骨髓、脂肪组织和牙齿组织的成骨分化至关重要。然而，人们对组蛋白甲基化在 hDPC 分化中的作用知之甚少。在此，我们对经历成牙诱导的 hDPC 中 HMT 和 HDM 的表达水平进行了分析。在几种差异表达的酶中，HDM KDM5A 在细胞分化过程中表现出显着增强的表达。此外，KDM5A 表达在早期传代期间增加，并且在成牙诱导期间以时间依赖性方式增加。使用表达 shRNA 的慢病毒，KDM5A 在 hDPC 中被敲低。 KDM5A 消耗导致碱性磷酸酶活性增强和矿物质沉积形成更多。同时，KDM5A 敲低使牙源标记物 DMP1、DSPP、OSX 和 OCN 的表达水平增加。作为一种特异性针对赖氨酸 4 处三甲基化和二甲基化组蛋白 H3 (H3K4me3/me2) 的组蛋白去甲基化酶，KDM5A 缺陷导致 H3K4me3 总水平显着增加，而 H3K4 me2 没有发现显着差异。 hDPC 中 KDM5A 敲低后，牙源标记启动子上的 H3K4me3 水平增加。 这些结果表明，KDM5A 存在于 hDPC 中，并通过从特定基因启动子中去除 H3K4me3 来抑制 hDPC 的牙源性分化潜力，表明 KDM5A 依赖性组蛋白去甲基化可能在修复性牙本质发生中发挥重要作用。