Tissue regeneration studies by controlled H3 K4/9/27me3 levels in adult mouse skin

摘要 组织再生治疗是现代生物学的一项重要研究内容。它的成功取决于我们的能力 控制成人组织干细胞(SCs)中细胞命运的决定。基因组的内在可塑性与串扰 干细胞与环境之间的关系是决定细胞命运的重要因素。特殊的表观遗传状态， 尤其是共价组蛋白修饰的基因组分布和总水平(例如，乙酰化， 甲基化)，对SC的命运和疾病都很重要。已经开发出了许多小分子抑制剂 在过去的十年里扰乱了组蛋白的修饰水平，其中一些已经被实现为 临床试验中的抗癌药物。然而，很少有人对成人组蛋白甲基化水平进行操控。 组织干细胞用于可能的组织再生控制。最近，我们报道了一种全球性的低甲基化 组蛋白H3K4/9/27me3，存在于小鼠皮肤的退行性变中，包括静止的毛囊干细胞中 (Hfscs)。根据我们的初步数据，我们假设H3K4/9/27me3水平的扰动允许 通过参与静止的干细胞中必不可少的信号通路来操纵组织再生。在这里我们 使用小分子靶向和我们新开发的小鼠遗传工具相结合的方式来操纵 H3K4/9/27me3在成年小鼠皮肤中的水平，并检查对组织再生(如毛囊)的影响 循环和伤口愈合)。我们也开始研究H3上游和下游的分子机制。 HfSCs中K4/9/27me3水平。特别是，我们首次在成年小鼠体内组织中解决了 稳态和新生RNA水平的差异及其与组蛋白的直接联系 甲基化水平。我们的工作对理解基因组可塑性的基础科学具有重要意义 静止组织干细胞和用于检查皮肤和毛囊的表观遗传学靶向药物的使用 再生疗法。

Abstract Tissue regeneration therapy is a major endeavour in modern biology. Its success is dependent upon our ability to control cell fate decisions in adult tissue stem cells (SCs). Intrinsic genome plasticity and the crosstalk between SCs and their environment are important factors in cell fate decisions. Specialized epigenetic states, and particularly the genomic distribution and overall levels of covalent histone modifications (e.g. acetylation, methylation), are important for SC fates and for disease. Many small molecule inhibitors have been developed over the past decade to perturb histone modification levels, and some have already been implemented as cancer drugs in clinical trials. However, little has been done to manipulate levels of histone methylation in adult tissue SCs for possible control of tissue regeneration. Recently, we reported a global hypomethylation of histone H3 K4/9/27me3 that occurs at catagen in mouse skin, including in the quiescent hair follicle stem cells (HFSCs). Based on our preliminary data we hypothesize that perturbation of H3 K4/9/27me3 levels allows manipulation of tissue regeneration by engaging with signalling pathways essential in quiescent SCs. Here we use a combination of small molecule targeting and our newly developed mouse genetic tools to manipulate the levels of H3 K4/9/27me3 in adult mouse skin, and examine effects on tissue regeneration (e.g. hair follicle cycle and wound healing). We also begin to examine molecular mechanisms upstream and downstream of H3 K4/9/27me3 levels in HFSCs. In particular, we address for the first time in an adult mouse tissue in vivo the difference between steady state mRNA levels and nascent RNA levels and establish the direct link with histone methylation levels. Our work has implications for understanding the basic science of genome plasticity in quiescent tissue SCs and for examining the use of epigenetics-targeting drugs to skin and hair follicle regenerative therapies.