Mechanisms that couple irregular development of fetal melanoblasts to premature exhaustion of adult melanocyte stem cells

胎儿黑色素细胞的不规则发育与成体黑色素细胞干细胞过早耗竭的机制

• 批准号: 10461955
• 负责人: PETER D. ADAMS
• 金额: $ 59.9万
• 依托单位: SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-04 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10461955
• 关键词: Address; Adult; Aging; Apoptosis; Back; Birth; Cell Aging; Cell Maintenance; Cells; Cessation of life; DNA Damage; Data; Defect; Degenerative Disorder; Deposition; Development; Disease; Elderly; Embryo; Embryonic Development; Enhancers; Environmental Exposure; Epigenetic Process; Exhibits; Fetal Development; Frequencies; Functional disorder; Genes; Genetic; Genetic Transcription; Hair; Histone H3; Histones; Hypopigmentation; Image; Impairment; In Vitro; Knock-out; Knockout Mice; Link; Maintenance; Malignant Neoplasms; Mediating; Mesenchymal; Molecular; Molecular Chaperones; Mus; Neural Crest; Newborn Infant; Oncogenes; PAX3 gene; Pathway interactions; Phenotype; Pigmentation physiologic function; Process; Proto-Oncogene Protein c-kit; Rattus; Role; Series; Signal Pathway; Signal Transduction; Specific qualifier value; Stem Cell Development; Stimulus; Stress; Sum; Testing; Therapeutic Intervention; Tissues; Transcriptional Regulation; Translating; Variant; Wild Type Mouse; adult stem cell; combat; developmental disease; embryonic stem cell; epigenetic memory; exhaust; exhaustion; human disease; in utero; in vivo; melanoblast; melanocyte; melanoma; multimodality; neoplastic; premature; programs; promoter; repaired; single-cell RNA sequencing; stem cell function; stem cell population; stem cells; telomere; tissue degeneration; transcription factor; transcriptomics; transmission process; wasting

PROJECT SUMMARY Maintenance of tissue function during adulthood, and hence suppression of tissue degeneration and disease, depends on maintenance of stem cell populations. Adult stem cells are epigenetically programmed and a culmination of a series of developmental decisions initiated in the embryo. In utero environmental exposures on the embryo can influence adult and late-life disease, likely in part via effects on stem cell development that are transmitted to maintenance and function of stem cells in the adult. However, the molecular links between embryonic development and long-term maintenance of stem cell function and phenotype in adults are poorly defined. We will employ lineage-specific genetic inactivation of a histone chaperone to understand how embryonic developmental integrity of melanoblasts (Mb) impacts on maintenance adult melanocyte (Mc) stem cells (McSC). The histone chaperone HIRA deposits histone variant H3.3 into active genes, promoters and enhancers. Through in vitro and in vivo studies and single cell RNA-seq of mouse embryo melanoblasts (Mbs) from wild type mice and mice lacking expression of HIRA in embryonic Mbs, we have uncovered a role for HIRA in sustaining the PAX3/SOX10-MITF Mb specification pathway. Inactivation of HIRA in Mbs depletes the number of Mbs in early/mid stage embryos. However, this embryonic defect is rescued by birth and young mice exhibit normal numbers of melanocytic cells, and only a very subtle pigmentation defect. Nevertheless, in new-born mice, Hira knock out (KO) melanocytic cells exhibit a higher frequency of telomere-associated DNA damage foci, indicating that Hira knock out McSC and/or melanocytes harbor molecular damage, even in new-born mice. Indeed, melanoblasts and melanocytes from new-born Hira KO mice respond poorly to pro-proliferative challenge in vitro and in vivo, and these mice show marked accelerated McSC and melanocyte depletion and dramatically accelerated hair greying during adulthood. Building on these extensive preliminary data, we will investigate the role of HIRA in differentiation and development of the melanocytic lineage, and investigate the links between abnormal embryonic development and adult stem cell depletion during adulthood and aging. Dysregulation of the PAX3/SOX10-MITF signaling pathway contributes to developmental disorders and melanoma. These studies to define HIRA's role in the PAX3/SOX10-MITF axis can promote therapeutic interventions to combat these developmental and neoplastic disorders. Moreover, completion of these Specific Aims will address how the integrity of embryonic development of tissue specific stem cells impacts maintenance of those stem cells during adulthood.

项目概要 维持成年期的组织功能，从而抑制组织变性和疾病， 取决于干细胞群的维持。成体干细胞经过表观遗传编程， 胚胎中开始的一系列发育决定的顶峰。子宫内环境暴露 胚胎可以影响成年和晚年疾病，部分可能是通过影响干细胞发育来实现的。 传递给成人干细胞的维持和功能。然而，分子之间的联系 成人的胚胎发育和干细胞功能和表型的长期维持较差 定义的。我们将采用组蛋白伴侣的谱系特异性基因失活来了解如何 黑素细胞（Mb）的胚胎发育完整性对维持成年黑素细胞（Mc）干细胞的影响 细胞（MCSC）。 组蛋白伴侣 HIRA 将组蛋白变体 H3.3 沉积到活性基因、启动子和增强子中。 通过体外和体内研究以及来自野生的小鼠胚胎黑素细胞 (Mbs) 的单细胞 RNA-seq 型小鼠和胚胎 Mb 中缺乏 HIRA 表达的小鼠，我们发现了 HIRA 在 维持 PAX3/SOX10-MITF Mb 规范途径。 Mbs 中 HIRA 失活会耗尽该数量 早期/中期胚胎中的 Mb。然而，这种胚胎缺陷在出生后得到了挽救，幼鼠表现出 黑素细胞数量正常，只有非常微妙的色素沉着缺陷。尽管如此，在新生儿 小鼠中，Hira 敲除 (KO) 黑素细胞表现出更高频率的端粒相关 DNA 损伤灶， 表明 Hira 敲除 McSC 和/或黑素细胞的分子损伤，即使在新生小鼠中也是如此。 事实上，新生 Hira KO 小鼠的成黑细胞和黑素细胞对促增殖反应很差 体外和体内的挑战，这些小鼠表现出明显加速的 McSC 和黑素细胞消耗 成年后头发变白的速度急剧加快。基于这些广泛的初步数据，我们将 研究 HIRA 在黑素细胞谱系分化和发育中的作用，并研究 胚胎发育异常与成年和衰老过程中成体干细胞耗竭之间的联系。 PAX3/SOX10-MITF 信号通路失调会导致发育障碍和 黑色素瘤。这些研究定义了 HIRA 在 PAX3/SOX10-MITF 轴中的作用，可以促进治疗 对抗这些发育障碍和肿瘤性疾病的干预措施。此外，完成这些具体 目标将解决组织特异性干细胞胚胎发育的完整性如何影响维持 这些干细胞在成年期间。