Sikder Sweta, Baek Songjoon, McNeil Truman, Dalal Yamini
Center for Cancer Research, National Cancer Institute/NIH, Bethesda, MD 20892, USA.
Center for Cancer Research, National Cancer Institute/NIH, Bethesda, MD 20892, USA; Saint Olaf College, 1520 St. Olaf Avenue, Northfield, MN 55057, USA.
Mol Cell. 2025 Feb 20;85(4):692-707.e7. doi: 10.1016/j.molcel.2024.12.018. Epub 2025 Jan 13.
Aging involves a range of genetic, epigenetic, and physiological alterations. A key characteristic of aged cells is the loss of global heterochromatin, accompanied by a reduction in canonical histone levels. In this study, we track the fate of centromeres in aged human fibroblasts and tissues and in various cellular senescent models. Our findings reveal that the centromeric histone H3 variant CENP-A is downregulated in aged cells in a p53-dependent manner. We observe repression of centromeric noncoding transcription through an epigenetic mechanism via recruitment of a lysine-specific demethylase 1 (LSD1/KDM1A) to centromeres. This suppression results in defective de novo CENP-A loading at aging centromeres. By dual inhibition of p53 and LSD1/KDM1A in aged cells, we mitigate the reduction in centromeric proteins and centromeric transcripts, leading to the mitotic rejuvenation of these cells. These results offer insights into a unique mechanism for centromeric inactivation during aging and provide potential strategies to reactivate centromeres.
衰老涉及一系列基因、表观遗传和生理变化。衰老细胞的一个关键特征是整体异染色质的丧失,同时伴随着经典组蛋白水平的降低。在本研究中,我们追踪了衰老的人类成纤维细胞和组织以及各种细胞衰老模型中着丝粒的命运。我们的研究结果表明,着丝粒组蛋白H3变体CENP - A在衰老细胞中以p53依赖的方式下调。我们观察到通过赖氨酸特异性去甲基化酶1(LSD1/KDM1A)募集到着丝粒的表观遗传机制抑制着丝粒非编码转录。这种抑制导致衰老着丝粒处新生CENP - A加载缺陷。通过对衰老细胞中的p53和LSD1/KDM1A进行双重抑制,我们减轻了着丝粒蛋白和着丝粒转录本的减少,从而使这些细胞的有丝分裂恢复活力。这些结果为衰老过程中着丝粒失活的独特机制提供了见解,并提供了重新激活着丝粒的潜在策略。