Defining post-transcriptional regulons in intestinal epithelial regeneration

定义肠上皮再生中的转录后调节子

• 批准号: 10375460
• 负责人: Kathryn Elizabeth Hamilton
• 金额: $ 53.08万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10375460
• 关键词: ATG3 gene; Affect; Apoptosis; Attenuated; Autophagocytosis; Binding; Binding Proteins; Biological Assay; Cell Count; Cell Line; Cells; Cellular biology; Chemicals; Clinical; Colon Carcinoma; DNA Damage; Data; Development; Disease; Epithelial; Epithelial Cells; Exhibits; Flow Cytometry; Gastrointestinal Injury; Gene Deletion; Genes; Genetic; Genetic Transcription; Goals; Homeostasis; Hydroxychloroquine; IGF2 gene; Immunofluorescence Immunologic; Infection; Inflammation; Injury; Intestines; Kinetics; Knock-out; LGR5 gene; Link; Luciferases; Mediating; Messenger RNA; Modeling; Molecular; Mus; Natural regeneration; Paneth Cells; Pathway interactions; Patients; Post-Transcriptional Regulation; Predisposition; Process; Proteins; RNA Biochemistry; RNA-Binding Proteins; Radiation; Radiation Tolerance; Reactive Oxygen Species; Regenerative capacity; Regulation; Regulon; Reporter; Ribosomes; Role; Stress; Testing; Tissues; Toxin; Transcript; Translations; Up-Regulation; Vesicle; Wild Type Mouse; Work; cancer cell; cell injury; chemotherapy; colon cancer cell line; epithelium regeneration; experience; functional group; gastrointestinal epithelium; improved; inhibition of autophagy; innovation; intestinal epithelium; intestinal injury; irradiation; mouse model; new therapeutic target; novel strategies; novel therapeutic intervention; novel therapeutics; overexpression; prevent; radiation-induced injury; radioresistant; repaired; response; ribosome profiling; self-renewal; stem cell function; stem cells

Radiation, inflammation, infection, and toxins can damage the integrity of the gastrointestinal epithelium. Mechanisms that initiate, facilitate, and subsequently attenuate regeneration are essential to prevent long-term damage or disease. Post-transcriptional regulons are groups of functionally-related mRNAs regulated primarily by RNA-binding proteins, which enable rapid, tissue-specific responses to cellular damage. This type of regulation is especially important in highly proliferative tissues such as the intestinal epithelium, where RNA-binding proteins may serve as “rheostats” for cellular and tissue adaptation. Our overarching goal is to identify novel strategies to enhance intestinal epithelial regeneration and improve therapies for patients, especially those who experience injury to the gastrointestinal epithelium as a result of radiation or chemotherapy. We discovered recently that epithelial regeneration is enhanced in mice with intestinal epithelial deletion of IMP1 (IGF2 mRNA-binding protein 1; also called IGF2BP1), in part via up-regulation of the autophagy pathway. Autophagy is a mechanism by which cells adapt and survive in response to stress. For example, recent studies in mouse models with autophagy gene deletion demonstrate increased susceptibility to irradiation-induced tissue damage. Defining the link between IMP1 and autophagy would contribute to an emerging paradigm of post-transcriptional regulons that serve as critical regulators of gastrointestinal epithelial regeneration. Aim 1 will examine the molecular mechanisms by which IMP1 regulates autophagy gene translation. We will use cell biology assays as well as ribosome-profiling in epithelial cells from mice with Imp1 deletion to define direct roles for IMP1 in autophagy (and other) gene translation. Aim 2 will evaluate how IMP1-mediated changes in autophagy contribute to stem cell dynamics at homeostasis using mouse models, autophagy assays, and enteroid-formation assays. Aim 3 will evaluate intestinal stem cell-specific roles of IMP1 in autophagy-mediated repair during irradiation-induced injury and subsequent regeneration. We will use mouse models of Imp1 deletion together with chemical or genetic deletion of autophagy to define how IMP1 normally functions during irradiation-induced injury and regeneration and whether this is autophagy-dependent. Successful completion of this proposal has the potential for both scientific and clinical impact and will provide a basis for improved or novel therapies for patients with radiation-induced (and potentially other) injury to the intestinal epithelium.

辐射、炎症、感染和毒素会损害胃肠上皮的完整性。启动、促进和随后减弱再生的机制对于预防长期损伤或疾病至关重要。转录后调节子是一组主要由 RNA 结合蛋白调节的功能相关 mRNA，能够对细胞损伤做出快速、组织特异性的反应。这种类型的调节在肠上皮等高度增殖的组织中尤其重要，其中 RNA 结合蛋白可以充当细胞和组织适应的“变阻器”。我们的首要目标是确定新的策略来增强肠上皮再生并改善患者的治疗，特别是那些因放疗或化疗而导致胃肠道上皮损伤的患者。我们最近发现，肠上皮缺失 IMP1（IGF2 mRNA 结合蛋白 1；也称为 IGF2BP1）的小鼠的上皮再生增强，部分是通过上调自噬途径实现的。自噬是细胞响应压力而适应和生存的一种机制。例如，最近对自噬基因缺失的小鼠模型的研究表明，对辐射引起的组织损伤的敏感性增加。定义 IMP1 和自噬之间的联系将有助于形成转录后调节子的新兴范例，该调节子可作为胃肠道上皮再生的关键调节因子。目标 1 将研究 IMP1 调节自噬基因翻译的分子机制。我们将使用细胞生物学测定以及 Imp1 缺失小鼠上皮细胞的核糖体分析来确定 IMP1 在自噬（和其他）基因翻译中的直接作用。目标 2 将使用小鼠模型、自噬测定和肠样形成测定来评估 IMP1 介导的自噬变化如何促进干细胞动态平衡。目标 3 将评估 IMP1 在辐射诱导损伤和随后的再生过程中自噬介导的修复中的肠干细胞特异性作用。我们将使用 Imp1 缺失的小鼠模型以及自噬的化学或遗传缺失来定义 IMP1 在辐射诱导的损伤和再生过程中如何正常发挥作用，以及这是否依赖于自噬。该提案的成功完成具有科学和临床影响的潜力，并将为肠上皮因辐射（以及可能的其他）损伤的患者提供改进或新颖的疗法奠定基础。