H3K36 methylation regulates cell plasticity and regeneration in the intestinal epithelium (CUT&Tag I). H3K36 methylation regulates cell plasticity and regeneration in the intestinal epithelium (CUT&Tag I)

Cell plasticity is needed during development and homeostasis to generate diverse cell types from stem and progenitor cells. Following differentiation, plasticity must be restricted in specialized cells to maintain tissue integrity and function. For this reason, specialized cell identity is highly stable under homeostatic conditions; however, cells in some tissues regain plasticity during injury-induced regeneration. While precise gene expression is needed to control these processes, the regulatory mechanisms that restrict or promote cell plasticity are poorly understood. Here, we use the mouse small intestine as a model system to study cell plasticity. We find that H3K36 methylation reinforces expression of cell type-associated genes to maintain specialized cell identity in intestinal epithelial cells. Depleting H3K36 methylation leads to defects in lineage commitment and activates a plastic, regenerative gene expression signature. Correspondingly, we observe rapid and reversible remodeling of H3K36 methylation following injury-induced regeneration. Together, these data suggest a fundamental role for H3K36 methylation in regulating cell plasticity and regeneration. Overall design: CUT&Tag for H3K27me3, H3K36me3, and H3K36me2 in WT H3 organoids at time 0, 24, 48, and 96 hours after irradiation, and H3K36M organoids after 4 weeks of induction, 2 biological replicates each.

细胞可塑性在发育与稳态过程中不可或缺，可介导干细胞及祖细胞分化产生多种细胞类型。细胞完成分化后，特化细胞的可塑性必须受到严格限制，以维持组织完整性与正常生理功能。正因如此，稳态条件下特化细胞的细胞身份高度稳定；然而部分组织中的细胞在损伤诱导的再生过程中会重新获得可塑性。尽管精确的基因表达调控对上述过程至关重要，但限制或促进细胞可塑性的分子调控机制仍不甚明晰。
本研究以小鼠小肠为模型系统开展细胞可塑性相关研究，发现H3K36甲基化（H3K36 methylation）可强化细胞类型特异性基因的表达，从而维持肠上皮细胞的特化细胞身份。敲除H3K36甲基化功能会导致细胞谱系定型缺陷，并激活兼具可塑性的再生基因表达特征。相应地，我们观察到在损伤诱导的再生过程中，H3K36甲基化会发生快速且可逆的表观遗传重塑。综上，本研究数据表明，H3K36甲基化在调控细胞可塑性与再生过程中发挥着基础性作用。
整体实验设计：对野生型（WT）H3类器官在辐照后0、24、48及96小时的H3K27me3、H3K36me3及H3K36me2进行CUT&Tag检测，同时对诱导4周后的H3K36M类器官开展相同检测，每组均设置2个生物学重复。