Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA.
Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Development. 2018 Jul 18;145(14):dev157149. doi: 10.1242/dev.157149.
Epigenetic regulation of gene expression has a crucial role allowing for the self-renewal and differentiation of stem and progenitor populations during organogenesis. The mammalian kidney maintains a population of self-renewing stem cells that differentiate to give rise to thousands of nephrons, which are the functional units that carry out filtration to maintain physiological homeostasis. The polycomb repressive complex 2 (PRC2) epigenetically represses gene expression during development by placing the H3K27me3 mark on histone H3 at promoter and enhancer sites, resulting in gene silencing. To understand the role of PRC2 in nephron differentiation, we conditionally inactivated the gene, which encodes a nonredundant component of the PRC2 complex, in nephron progenitor cells. Resultant kidneys were smaller and showed premature loss of progenitor cells. The progenitors in mutant mice that were induced to differentiate did not develop into properly formed nephrons. , normally expressed in the renal vesicle, was overexpressed in kidneys of mutant mice. Thus, PRC2 has a crucial role in suppressing the expression of genes that maintain the progenitor state, allowing nephron differentiation to proceed.
基因表达的表观遗传调控在器官发生过程中对于干细胞和祖细胞群体的自我更新和分化起着至关重要的作用。哺乳动物的肾脏维持着一群自我更新的干细胞,这些干细胞分化为数千个肾单位,肾单位是执行过滤功能以维持生理内稳态的功能单位。多梳抑制复合物 2 (PRC2) 通过在启动子和增强子位点上将 H3K27me3 标记放置在组蛋白 H3 上来抑制发育过程中的基因表达,从而导致基因沉默。为了了解 PRC2 在肾单位分化中的作用,我们条件性地使编码 PRC2 复合物非冗余成分的 基因在肾祖细胞中失活。由此产生的肾脏较小,并显示出祖细胞的过早丧失。在诱导分化的 突变小鼠的祖细胞中,没有发育成适当形成的肾单位。 在 突变小鼠的肾脏中过表达,在肾小囊中正常表达。因此,PRC2 对于抑制维持祖细胞状态的基因的表达起着至关重要的作用,从而允许肾单位分化进行。