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是一生的连续。它是 研究有助于阐明红细胞疾病，最著名的是贫血，占所有残疾的8.8％ 全球。它也是一个可访问的模型，用于研究发育生物学中的基本问题。这 提案是基于最近的发现，即关键的红细胞命运决定与戏剧性有关 S相缩短。其他一些发育系统中的细胞脂肪决策与 更快的阶段。更快的s相可能是以基因组不稳定性为代价来实现的，如癌基因 - 诱导复制应力。但是，研究身体更快的阶段与 缺乏正常发育中的DNA损伤响应。该项目的目标是确定是否 红细胞发育开关实体的异常快速S阶段改变了DNA复制保真度和/或 DNA损伤反应的改变。 早期的红细胞祖细胞，称为“菌落形成单位 - 侵蚀性”（CFU-E），经历了几个自我更新细胞 过渡到红细胞终末分化（ETD）之前，它们开始表达红细胞 基因。从自我更新CFU-E祖细胞过渡到成熟的ETD红细胞是一个迅速 转录开关与单个细胞周期s相同步并取决于单个单元期。令人惊讶的是， CFU-E/ETD开关的S期独特的持续时间仅持续4小时，而7小时内则持续4小时 由于全球循环的结果，复制叉速度上升了50％。这些变化 在S中，CFU-E/ETD开关需要相位速度； CFU-E祖细胞的S阶段较慢促进 他们的自我更新，而ETD早期的快速S阶段促进了红细胞基因诱导。可能是可以预料的 早期ETD红细胞的快速S阶段完全将是增加复制叉停滞事件的“成本” （“复制应力”）和增加的基因组不稳定性。我们的实验目的测试两个相对但没有测试 一定是相互排斥的假设： 假设1：以质量较低的复制成本实现了早期ETD的更快S阶段。 假设2：早期ETD的S阶段更快地反映了“增压”复制耦合的DNA修复。 AIM 1将分析快速循环早期ETD成年细胞中DNA复制的质量。 AIM 2将确定 快速循环ETD的DNA损伤响应与较慢的循环cfu-的DNA损伤反应不同 E前体。 AIM 3将确定较快的S相和早期的DNA损伤响应是否改变 ETD在遗传上是分开的。