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.
The regulation of Drosophila intestinal stem cell (ISC) homeostasis is remarkably similar to one of mammalian gut and also lung. Due to its genetic amenability and state-of-the art tools flies can be used in a number of high-throughput discovery and hypothesis based interrogations as ones described in this proposal. Using Drosophila and its ISC as a model, the goal of the proposed research is to identify and characterize effects of gut cell-cell interactions and effects of endogenous age-associated environment on ISC aging thereby providing novel insights into age-associated dysregulation of stem cell activity.
| Avanesov, Andrei S; Ma, Siming; Pierce, Kerry A et al. (2014) Age- and diet-associated metabolome remodeling characterizes the aging process driven by damage accumulation. Elife 3:e02077 |
