The DNA damage response of fast-cycling erythroblasts

快速循环有红细胞的DNA损伤反应

• 批准号: 10317904
• 负责人: Ralph Scully
• 金额: $ 59.8万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-25 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10317904
• 关键词: Affect; Anemia; Biochemical; Bone Marrow; Bone Marrow Cells; CFU-E; Cell Cycle; Cell Maturation; Cell Survival; Cell division; Cells; Chromatids; Copy Number Polymorphism; Coupled; DNA Damage; DNA Interstrand Crosslinking; DNA Repair; DNA biosynthesis; DNA replication fork; Data; Development; Developmental Biology; Disease; Erythroblasts; Erythrocytes; Erythroid; Erythroid Cells; Erythropoiesis; Erythropoietin Receptor; Event; Failure; Fanconi Anemia pathway; Fanconi' s Anemia; Genes; Genetic Transcription; Genome; Genomic Instability; Goals; Lead; Life; Measures; Mitomycin C; Modality; Mus; Oncogenes; Pathway interactions; Physiological; Process; Reporter; Resistance; S Phase; Site; Speed; Study models; System; Testing; Wild Type Mouse; base; cost; disability; gene induction; genome integrity; genome sequencing; homologous recombination; in vivo; indexing; inhibitor/antagonist; mouse model; novel; progenitor; programs; repaired; replication stress; response; self-renewal; whole genome

Project Summary Erythropoiesis, or the process of red cell formation, is continuous throughout life. Its study helps elucidate erythroid disorders, most notably anemia, which accounts for 8.8% of all disability globally. It is also an accessible model for studying fundamental questions in developmental biology. This proposal is based on recent finding that a key erythroid cell fate decision is associated with dramatic shortening of S phase. Cell fate decisions in some other developmental systems are similarly associated with a faster S phase. A faster S phase might be accomplished at the cost of genomic instability, as in oncogene- induced replicative stress. However, studies of the relationships between a physiologically faster S phase and the DNA damage response in normal development are lacking. This project’s goal is to determine whether the unusually fast S phase of the erythroid developmental switch entails altered DNA replication fidelity and/or alterations in the DNA damage response. Early erythroid progenitors, termed ‘colony-forming-unit-erythroid’ (CFU-e), undergo several self-renewal cell divisions before transitioning into Erythroid Terminal Differentiation (ETD), where they begin to express red cell genes. The transition from self-renewing CFU-e progenitors to maturing ETD erythroblasts is a rapid transcriptional switch that is synchronized with, and dependent on, a single cell cycle S phase. Strikingly, the S-phase of the CFU-e/ETD switch is of uniquely short duration, lasting only 4 hr, compared with 7 hr in preceding CFU-e cycles, as a result of a global, 50% increase in the speed of replication forks. These changes in S phase speed are required for the CFU-e/ETD switch; the slower S phase of CFU-e progenitors promotes their self-renewal, while the fast S phase of early ETD promotes erythroid gene induction. It might be expected that the fast S phase of early ETD erythroblasts would exact a ‘cost’ of increased replication fork stalling events (‘replication stress’) and increased genomic instability. our experimental AIMS test two opposing but not necessarily mutually exclusive hypotheses: Hypothesis 1: The faster S phase of early ETD is achieved at a cost of lower quality replication. Hypothesis 2: The faster S phase of early ETD reflects “supercharged” replication-coupled DNA repair. AIM 1 will analyze the quality of DNA replication in fast-cycling early ETD erythroblasts. AIM 2 will determine how the DNA damage response of fast-cycling ETD erythroblasts differs from that of their slower-cycling CFU- e precursors. AIM 3 will determine whether the faster S phase and the altered DNA damage response of early ETD are genetically separable.

项目摘要 红细胞生成或红细胞形成过程在整个生命过程中持续进行。它是 研究有助于阐明红细胞疾病，尤其是贫血，占所有残疾的 8.8% 全球。它也是研究发育生物学基本问题的一个易于使用的模型。这 该提案基于最近的发现，即关键的红细胞命运决定与戏剧性的 S期缩短。一些其他发育系统中的细胞命运决定同样与 较快的S期。更快的 S 期可能是以基因组不稳定为代价来实现的，就像癌基因一样 诱发复制应激。然而，对生理上较快的 S 期与 正常发育中缺乏DNA损伤反应。该项目的目标是确定是否 红系发育开关异常快速的 S 期需要改变 DNA 复制保真度和/或 DNA损伤反应的改变。 早期红系祖细胞，称为“红系集落形成单位”(CFU-e)，经历多次自我更新细胞 在转变为红细胞终末分化 (ETD) 之前进行分裂，开始表达红细胞 基因。从自我更新的 CFU-e 祖细胞到成熟的 ETD 红细胞的转变是一个快速的过程 与单个细胞周期 S 期同步且依赖于单个细胞周期 S 期的转录开关。引人注目的是， CFU-e/ETD 切换的 S 相持续时间非常短，仅持续 4 小时，而在 CFU-e/ETD 中则为 7 小时。 之前的 CFU-e 周期，由于复制叉的速度全局提高了 50%。这些变化 CFU-e/ETD 开关需要 S 相速度； CFU-e 祖细胞较慢的 S 期促进 它们的自我更新，而早期 ETD 的快速 S 期促进红细胞基因诱导。或许可以期待 早期 ETD 有红细胞的快速 S 期将增加复制叉停滞事件的“成本” （“复制压力”）和基因组不稳定性增加。我们的实验目标测试了两个相反但不 必然相互排斥的假设： 假设 1：早期 ETD 的更快 S 期是以较低质量复制为代价实现的。 假设 2：早期 ETD 较快的 S 期反映了复制耦合 DNA 修复的“增压”。 AIM 1 将分析快速循环的早期 ETD 有红细胞中 DNA 复制的质量。 AIM 2 将确定 快速循环的 ETD 成红细胞的 DNA 损伤反应与慢速循环的 CFU 有何不同 e 前体。 AIM 3 将确定是否有更快的 S 期和早期 DNA 损伤反应的改变 ETD 在基因上是可分离的。