Elucidating the role of ER remodeling in aging of C. elegans

项目摘要/摘要 人口老龄化暴露了慢性病和与年龄相关的疾病的负担，通过 了解导致衰老的遗传和环境因素，我们将更适合发展和 测试延缓年龄相关疾病的治疗方法。由于生物衰老既受遗传因素的影响，也受 环境，我们的实验室研究衰老的细胞和分子驱动因素，特别是 疾病中的细胞器通讯。在这里，我们新描述了一种戏剧性的内质重组 线虫老化过程中的内质网(ER)亚域。内质网通过这些途径调节细胞间和细胞内的信号传递。 薄层和小管域，以及薄层：小管平衡对细胞功能至关重要。ER小管存储钙和 脂质，在特殊的膜接触部位，它们调节线粒体的动力学。我们发现，老龄化 ER经历了粗大的ER片层的丢失和光滑的ER小管的扩张，我们的数据表明 改变内质网结构足以在年龄中保存线粒体形态，使内质网成为一种潜在的 在防止与年龄相关的线粒体碎裂方面的目标。尽管自噬被认为是一种细胞保护 随着年龄的增长，我们发现自噬对于年龄相关的内质网重塑是必要的。这可以用ER来解释- 吞噬，内质网选择性自噬的一种形式，在衰老的背景下还没有被研究过，就像内质网吞噬份额 常见的回收流程。最后，我们证明了卡路里限制，延长了寿命，防止了 这种与年龄相关的内质网形态丧失。因此，我们假设不受调控的内质网吞噬会导致年龄增长- 相关的内质网重塑，饮食限制通过减轻这种内质网形式和 功能。为了辨别这些变化是否归因于选择性内质网吞噬，而不是一般的 自噬，我将使用体内成像、荧光记者和RNAi相结合的方法来研究 导致ER亚区随年龄变化的分子机制(目标1)。在《目标2》中，我将使用节食 限制，一个稳健的长寿范式，以探讨内质网重构的原因(S)和后果(S) 健康寿命和寿命调控。这项工作将在范德比尔特大学的监督下进行 细胞与发育生物学助理教授克里斯托弗·伯克维茨博士发现了ER的角色 内质网-线粒体串扰在寿命调节中的作用。我还会得到大卫博士的支持 米勒是细胞与发育生物学教授，他的实验室在电子显微镜和 我开创了许多基因工程技术，我将在线虫身上进行试验。在这些研究中，我将收到 来自强大的咨询委员会的反馈，该委员会具有细胞器间信号转导、膜 动力学和衰老生理学。这个项目的成功完成不仅将增进我们对 细胞生物学和内质网在衰老中的作用，但也建立内质网的结构和功能作为治疗的靶点 在治疗与年龄相关的疾病方面。

PROJECT SUMMARY/ABSTRACT An aging human population has revealed the burden of chronic illness and age-related disease, and by understanding the genetic and environmental factors that drive aging, we will be better suited to develop and test therapeutics that slow age-related disease. As biological aging is influenced by both genetics and the environment, our laboratory studies the cellular and molecular drivers of aging, with a particular focus on inter- organelle communication in disease. Here, we newly describe a dramatic reorganization of endoplasmic reticulum (ER) subdomains in aging C. elegans. The ER mediates inter- and intracellular signaling through these sheet and tubule domains, and sheet:tubule balance is critical for cell function. ER tubules store calcium and lipids, and at specialized membrane contact sites, they regulate mitochondrial dynamics. We find that the aging ER undergoes a loss of rough ER sheets and expansion of smooth ER tubules, and our data suggest that modifying ER structure is sufficient to preserve mitochondrial morphology in age, making the ER a potential target in preventing age-related mitochondrial fragmentation. Though autophagy is seen as cytoprotective in aging, we show that autophagy is necessary for age-related ER remodeling. This may be explained by ER- phagy, a form of ER-selective autophagy that has not been studied in the context of aging, as ER-phagy shares common recycling processes. Finally, we demonstrate that caloric restriction, which extends lifespan, prevents this age-related loss of ER morphology. Therefore, we hypothesize that dysregulated ER-phagy drives age- related ER remodeling and that dietary restriction promotes longevity by mitigating this loss of ER form and function. To discern whether these changes are attributable to selective ER-phagy, rather than general autophagy, I will use a combination of in vivo imaging, fluorescent reporters, and RNAi to investigate the molecular mechanisms leading to a change in ER subdomains with age (Aim 1). In Aim 2, I will use dietary restriction, a robust longevity paradigm, to investigate the cause(s) and consequence(s) of ER remodeling in healthspan and lifespan regulation. This work will be conducted at Vanderbilt University under the supervision of Dr. Kristopher Burkewitz, Assistant Professor of Cell & Developmental Biology, who discovered roles for ER function in lifespan regulation through ER-mitochondrial crosstalk. I will additionally be supported by Dr. David Miller, Professor of Cell & Developmental Biology, whose lab is experienced in electron microscopy and pioneered many genetic engineering techniques I will perform in C. elegans. In these studies, I will receive feedback from a strong advisory committee with expertise including interorganelle signaling, membrane dynamics, and aging physiology. Successful completion of this project will not only advance our understanding of cell biology and the role of the ER in aging but also establish ER structure and function as therapeutic targets in the treatment of age-related disease.