Sikder Sweta, Baek Songjoon, McNeil Truman, Dalal Yamini
bioRxiv. 2024 Sep 12:2023.12.30.573721. doi: 10.1101/2023.12.30.573721.
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 during aging in human cells. 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 mitotic rejuvenation of these cells. These results offer insights into a novel mechanism for centromeric inactivation during aging and provide potential strategies to reactivate centromeres.
衰老涉及一系列遗传、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,我们追踪了人类细胞衰老过程中着丝粒的命运。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,从而使这些细胞有丝分裂年轻化。这些结果为衰老过程中着丝粒失活的新机制提供了见解,并提供了重新激活着丝粒的潜在策略。