Functional examination of age-related stem cell dysfunction in the Drosophila gut

描述(由申请人提供)：本提案概述了一种实验策略，旨在了解果蝇模型中与年龄相关的干细胞功能失调。成年果蝇的肠道上皮由常驻干细胞维持，这些干细胞对所有类型的肠道上皮细胞都有贡献。这些肠道干细胞(ISCs)在组织损伤和衰老时分裂，但似乎失去了对其增殖极限的控制。具体地说，AGIG导致ISC过度增殖，其本身类似于我们在哺乳动物癌症模型中发现的病理情况。因此，了解与年龄相关的干细胞功能障碍的机制可能有助于理解高等生物体(如人类)中癌症的机制。我们将通过解决该领域的两个相关问题，开始填补我们目前对干细胞老化的理解的空白。在第一个目标中，我们将试图了解 肠道老化，特别关注细胞自主和非自主衰老信号在ISC老化和过度增殖中的作用。我们将在果蝇系统中利用成熟的方法，这将使我们能够在基因上操纵肠道中的ISCs及其谱系。我们还将使用抗体来揭示肠道细胞老化的速度。我们的第二个目标将扩展代谢物图谱方面的新技术，以表征苍蝇衰老环境的内源性小分子含量。然后，我们将使用计算方法和严格的统计分析，有效地确定最可能的长寿候选者 并将测试它们在寿命和干细胞老化方面的作用。虽然我们的代谢物图谱可能提供干细胞老化的小分子调节因子的结构信息，但互补的基因表达研究可能有助于在苍蝇肠道中以细胞特异性的方式对上游遗传电路进行功能分析。

DESCRIPTION (provided by applicant): This proposal outlines an experimental strategy aimed at understanding age-dependent dysregulation of stem cell function in the Drosophila model. The adult Drosophila intestinal epithelium is maintained by resident stem cells which contribute to all gut epithelial cell types. These intestinal stem cells (ISCs) divide in response o tissue damage and aging, but appear to lose control of their proliferative limit. Specifically, agig leads to ISC hyperproliferation, which is in itself similar to pathological conditions we find in mammalian models of cancer. Thus, understanding the mechanisms for age-associated stem cell dysfunction may illuminate on the mechanisms of cancer in higher organisms, such as humans. We will begin filling gaps in our current understanding of stem cell aging by addressing two relevant problems in the field. In the first aim, we will attempt to understand the dynamics of gut aging, specifically focusing on the contribution of cell autonomous and cell non-autonomous aging cues on ISC aging and hypeproliferation. We will utilize well established methods in Drosophila system which will allow us to genetically manipulate the ISCs and their lineage in the gut. We will also use antibodies that reveal the rate of gut cell aging. Our second aim will expand on the new techniques in metabolite profiling to characterize the endogenous small molecule content of the aging environment in flies. We will then use computational methods and stringent statistical analysis, which efficiently identifies the most probable longevity candidates and will test their role on lifespan and stem cell aging. While our metabolite profiling may offer structural information of small molecule regulators of the stem cell aging, the complementary gene expression studies may illuminate on upstream genetic circuitries which can be functionally analyzed in cell-specific manner in the fly gut.