Understanding the aging process in hematopoietic stem cells by alcohol-induced DNA damage

项目摘要 酒精是人类DNA损伤的常见潜在来源。实际上，它的代谢副产物， 乙醛和活性氧（ROS）使造血干细胞（HSC）突变。重要的是，DNA 损伤是衰老过程的核心，它导致干细胞耗竭、细胞衰老、炎症， 以及解除营养感应的管制总之，这些发现使我们假设酒精诱导的DNA 损伤加速HSC的老化。此外，老年HSC具有髓样偏向性分化，减少的长 长期再繁殖潜力和DNA修复功能下降，这可能使他们更容易被感染。 易受酒精诱导的DNA损伤。先前的研究使用非常高剂量的酒精来研究他们的行为。 DNA损伤对HSC的影响，这很难推广到更广泛的老龄化人群， 仅适量饮酒。此外，一般来说，适度饮酒对整体健康的影响 人口仍有争议。本提案的总体目标是阐明HSC的关键方面 使用基于细胞的和动物模型的衰老。我们的目标是确定修复酒精所必需的DNA修复基因- 通过合并的CRISPR筛选诱导HSC中的DNA损伤。我们还旨在确定老化的HSC是否 使用小鼠骨髓移植模型和单细胞 RNA测序方法。我们提出的研究将揭示修复酒精引起的DNA损伤的基因 及其有毒的代谢副产物。它还将告诉我们，老化的HSC对酒精诱导的HSC的反应是如何不同的。 DNA损伤比年轻的HSC。确定DNA损伤反应和DNA修复的关键差异， 老化的HSC将使我们能够发现预防因酒精和其他潜在原因导致的衰老的方法。 内源性和外源性DNA损伤剂。

Project Summary Alcohol is a common potential source of DNA damage in humans. Indeed, its metabolic byproducts, acetaldehyde and reactive oxygen species (ROS), mutate hematopoietic stem cells (HSCs). Importantly, DNA damage is central to the aging process by contributing to stem cell exhaustion, cellular senescence, inflammation, and deregulated nutrient sensing. Together, these findings have led us to hypothesize that alcohol-induced DNA damage accelerates aging in HSCs. Moreover, aged HSCs have myeloid-biased differentiation, reduced long- term repopulating potential and decreased DNA repair function, which may lend themselves to being more vulnerable to alcohol-induced DNA damage. Prior research has used very high doses of alcohol to study their DNA-damaging effects on HSCs, which is difficult to generalize to the broader aging population who may enjoy only moderate alcohol drinking. Also, the effects of moderate alcohol consumption on overall health in the general population remain controversial. The overarching goal of this proposal is to shed light on the key aspects of HSC aging using cell-based and animal models. We aim to identify DNA repair genes essential for repairing alcohol- induced DNA damage in HSCs by a pooled CRISPR screen. We also aim to determine whether aged HSCs are more vulnerable to moderate alcohol drinking using a mouse bone marrow transplant model and a single-cell RNA-sequencing approach. Our proposed studies will reveal genes that repair DNA lesions caused by alcohol and its toxic metabolic by-products. It will also inform us how aged HSCs respond differently to alcohol-induced DNA damage than younger HSCs. Identification of key differences in DNA damage response and DNA repair in aged HSCs will enable us to uncover ways to prevent aging due to alcohol and potentially due to other endogenous and exogenous DNA damaging agents as well.