The DNA damage response of fast-cycling erythroblasts

快速循环有红细胞的DNA损伤反应

基本信息

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
项目类别：
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&apos 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

项目摘要

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。研究有助于阐明红细胞疾病，最显着的贫血，占所有残疾的 8.8% 它也是研究发育生物学基本问题的可用模型。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其他一些发育系统中 S 期的缩短也与细胞命运决定类似。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。然而，对生理上较快的 S 期与复制应激之间关系的研究。该项目的目标是确定正常发育中是否缺乏 DNA 损伤反应。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)，经历多个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。转录开关与单个细胞周期 S 期同步且依赖于该细胞周期。 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。由于复制分叉的速度全局提高了 50%，因此之前的 CFU-e 周期发生了这些变化。 CFU-e/ETD 切换需要 S 期速度；CFU-e 祖细胞的 S 期速度较慢；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。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”）和增加的基因组不稳定性我们的实验目标测试了两个相反但不是的。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 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 AIM 3 前体将决定是否有更快的 S 期和早期 DNA 损伤反应的改变。 ETD 在基因上是可分离的。