Investigation of compartmental PDHX during cellular senescence

细胞衰老过程中PDHX分室的研究 维持体内平衡的能力决定了细胞的整体健康和这种平衡的失调。 这一过程可最终导致细胞功能丧失和组织退化，最终导致机体 衰老衰老是一个高度复杂的过程，有几个不同的细胞标志，包括表观遗传 改变、线粒体功能障碍、营养感测和细胞衰老。虽然这些老化与 生物过程是不同的，它们是高度相互关联的，因为一个标志的扰动会影响 一个或多个与年龄相关的过程。细胞衰老，细胞限制其增殖的过程 分裂的能力和停止是衰老的标志，并与年龄相关的疾病有关。衰老细胞 经历了染色质景观和新陈代谢的重新布线。虽然研究已经解决了这些问题， 虽然这些代谢和表观遗传学的变化是单独的，但很少有人研究这些代谢和表观遗传学在细胞内的串扰。 衰老已知代谢酶和复合物通过提供染色质库来调节染色质。 表观遗传酶可以利用其催化活性的代谢物。去发现潜在的代谢- 在衰老的表观遗传轴，我进行了代谢靶向CRISPR文库筛选复制 衰老，并确定了丙酮酸脱氢酶复合物组分X（PDHX）的缺失延迟 衰老PDHX是丙酮酸脱氢酶复合物的组分，并且主要定位在 然而，我们发现线粒体的核亚型在衰老中上调，PDHX增加， 它在衰老过程中与染色质的联系。PDHX在线粒体中的免疫沉淀， 与细胞核相比，表明不同的蛋白质相互作用，表明独特的隔室功能。由于 根据PDHX在代谢中的功能和我们关于其与染色质相互作用的初步数据，我们假设 PDHX在协调细胞衰老所需的代谢和染色质动力学方面起着关键作用。 因此，提案的完成将有助于阐明代谢和代谢之间的潜在串扰。 表观遗传学在衰老中的作用

INVESTIGATION OF COMPARTMENTAL PDHX IN CELLULAR SENESCENCE The capacity to maintain homeostasis determines the overall health of the cell and the dysregulation of this process can culminate into loss of cellular function and tissue deterioration ultimately leading to organismal aging. Aging is a highly complex process with several distinct cellular hallmarks which include epigenetic alteration, mitochondrial dysfunction, nutrient sensing, and cellular senescence. While these aging associated biological processes are distinct, they are highly interconnected as the perturbation of one hallmark will affect one or multiple other age-related processes. Cellular senescence, the process where a cell limits its proliferative ability and ceases to divide is a hallmark of aging and implicated in age-related diseases. Senescent cells undergo a rewiring of its chromatin landscape as well as its metabolism. While studies have addressed these changes individually, few have examined the crosstalk of these metabolism and epigenetics in cellular senescence. Metabolic enzymes and complexes have been known to regulate chromatin by providing pools of metabolites that can be utilized by epigenetic enzymes for their catalytic activity. To uncover potential metabolic- epigenetic axis in senescence, I performed a metabolic targeted CRISPR library screen in replicative senescence and identified the deletion of Pyruvate Dehydrogenase Complex Component X (PDHX) delays senescence. PDHX is a component of the pyruvate dehydrogenase complex and is primarily localized within the mitochondria, however, we identified that a nuclear isoform is upregulated in senescence and PDHX increases its association with chromatin during senescence. Immunoprecipitation of PDHX in the mitochondria as compared to the nucleus indicates distinct protein interactions suggesting unique compartmental functions. Due to the function of PDHX in metabolism and our preliminary data of its interaction on chromatin, we hypothesize PDHX plays a key function in coordinating metabolism and chromatin dynamics required for cellular senescence. Thus, the completion of the proposal will identify help elucidate a potential crosstalk between metabolism and epigenetics in senescence and aging.