Dissection of a Developmental Checkpoint That Preserves Regenerative Capacity

剖析保留再生能力的发育检查点

基本信息

批准号：
8458939
负责人：
ADRIAN J HALME
金额：
$ 28.97万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-05-01 至 2017-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8458939
关键词：
Address Adult Aging Anabolism Biological Assay Biological Metamorphosis Brain Cachexia Cell Cycle Checkpoint Chimeric Proteins Chronic Clinical Competence Cues Data Development Developmental Delay Disorders Disease Dissection Drosophila genus Drosophila melanogaster Ecdysone Endocrine Epithelial Evolution Feedback Genetic Genetic Epistasis Goals Growth Homologous Gene In Situ Hybridization Inflammation Injury Insulin Resistance Larva Ligands Malignant Neoplasms Mediating Metabolic Modeling Molecular Molecular Genetics Natural regeneration Neurons Neurosecretory Systems Nuclear Receptors Obesity Organism Pathway interactions Patients Phase Regulation Reporter Research Retinoids Role Signal Pathway Signal Transduction Staging Stem cells Structure TNF gene Testing Time Tissues Transgenic Organisms Transplantation analog design forkhead protein human tissue imaginal disc in vivo insight insulin signaling programs receptor regenerative repaired research study response tissue regeneration

项目摘要

DESCRIPTION (provided by applicant): The experiments described in this proposal examine a newly defined regulatory mechanism, a developmental checkpoint - the developmental analogue of a cell-cycle checkpoint - that is activated by tissue damage during larval growth of the fruit fly, Drosophila melanogaster. This developmental checkpoint regulates systemic endocrine and metabolic signals to delay development and preserve the regenerative capacity of damaged tissues. The systemic influences on the regenerative capacity of tissues are poorly understood. Therefore, a mechanistic understanding of this developmental checkpoint will provide an important, new insight into the regulation of the systemic signals that control regenerative growth. The aims of the research described in this proposal are to build on our initial observations and further define each of the key steps within this developmental checkpoint. First, this proposal explores how retinoid signaling, which participates in checkpoint activation, functions to regulate neuroendocrine activity in the larval brain and produce developmental delay. The relevant functional localization of retinoid biosynthesis during damage will be examined using transgenic constructs, in situ hybridization, and tissue-targeted inhibition and rescue of retinoid biosynthesis. Molecular and genetic experiments will be used to determine the role of retinoids in inhibiting a neuroendocrine positive feedback loop that regulates developmental progression. Second, experiments in this proposal are designed to identify the "damage signal" that regulates the systemic responses to localized tissue damage. Genetic epistasis experiments will be used to test the role of Eiger, the Drosophila TNF homologue, in producing the systemic damage signal that mediates the developmental checkpoint activation. At the same time, unbiased genetic approaches will also be used to establish the identity of the damage signal. Third, this proposal examines the systemic metabolic effects produced by localized tissue damage. The effect of local tissue damage on systemic insulin signaling will be examined using several tissue-specific and systemic reporters, and the role of altered insulin signaling in checkpoint delay will be examined using tissue-targeted inhibition of the forkhead-transcription factor, dFoxo. Completion of the experiments described in this proposal will provide valuable new insights into the regulation of the systemic signals that control tissue regeneration. In addition, these experiments will reveal the mechanisms by which persistent tissue damage and inflammation can produce systemic effects on growth and endocrine control of development, which are each observed in clinical examples of persistent inflammation such as obesity-related insulin resistance and cancer cachexia.

描述（由申请人提供）：本提案中描述的实验检查了一种新定义的调节机制，一种发育检查点 - 细胞周期检查点的发育类似物 - 在果蝇幼虫生长过程中，该机制被组织损伤激活，果蝇果蝇果蝇。该发育检查点调节系统性内分泌和代谢信号，以延迟发育并保留受损组织的再生能力。对组织再生能力的全身影响知之甚少。因此，对该发展检查点的机械理解将为控制再生增长的系统信号的调节提供一个重要的新见解。本提案中描述的研究的目的是建立我们的最初观察结果，并进一步定义此发育检查点中的每个关键步骤。首先，该提案探讨了参加检查点激活的类视黄素信号如何调节幼虫大脑中神经内分泌活性并产生发育延迟。在损伤过程中，将使用转基因构建体，原位杂交以及靶向组织的抑制和挽救视网膜类动物生物合成的相关功能定位。分子和遗传实验将用于确定类维生素类动物在抑制调节发育进展的神经内分泌阳性反馈环中的作用。其次，本提案中的实验旨在确定调节对局部组织损伤的全身反应的“损害信号”。遗传性上述实验将用于测试果蝇TNF同源物Eiger在产生介导发展检查点激活的系统性损伤信号中的作用。同时，公正的遗传方法也将用于建立损伤信号的身份。第三，该提案检查了局部组织损伤产生的全身代谢作用。将使用几个组织特异性和全身记者检查局部组织损伤对全身胰岛素信号传导的影响，并且将使用以组织为目标的抑制叉子转录因子DFOXO DFOXO来检查胰岛素信号改变在检查点延迟中的作用。本提案中描述的实验的完成将为控制组织再生的系统信号的调节提供宝贵的新见解。此外，这些实验将揭示持续组织损伤和炎症的机制，可以对发育的生长和内分泌控制产生全身影响，这在持续性炎症的临床实例中都可以观察到，例如肥胖相关胰岛素抵抗和癌症cachexia。