The proposed work will examine how cell response is influenced by the neurodegenerative brain caused by Alzheimer's disease. The Pi is interested in the behavior of stem cells as these unique and important cells have great promise for the treatment of Alzheimer's disease (AD) and other neurodegenerative disorders. Some positive results have been obtained in animal studies of AD suggesting that neural stem cells support healthy brain function. Yet, there have also been contradictory reports that beta-amyloid peptide, the primary protein component in senile plaques found in AD, may damage stem cells. Even if stem cell therapies in AD animal studies are unambiguous successes, there are still considerable challenges associated with translating those advances to clinical treatments for humans, in part because of differences between human and animal models of AD, and differences in stem cell behavior between humans and rodents. Thus, a molecular-level understanding of the impact of the AD environment on human neural stem cells will be imperative prior to clinical translation of stem cell therapies. It is proposed to explore the molecular basis for neural stem cell response in an AD-like culture environment that will inform our understanding of the potential behavior of neural stem cells in the neurodegenerative brain. The work combines bioengineering with neuroscience and thus relates to CBET areas of interest. The proposed work is appropriate for an EAGER mechanism as it is exploratory, based on a new, unproven hypothesis, but if successful, could lead to new transformational discoveries at the interface between engineering and neuroscience. Thus, in this project graduate and undergraduate students will be trained in an interdisciplinary environment. The unique resources at UMBC such as the Meyerhoff program, will be leveraged to recruit diverse undergraduates and graduate students into the program providing mentoring and training experiences that will enhance their academic and professional development.
It is proposed to examine the role of beta-amyloid and the AD environment on neural stem cell fate in cultures that provide a soft, three-dimensional (3D) environment which is particularly important in light of the recent findings by the PI that suggests a role of integrin signaling in both neural stem cell differentiation and beta-amyloid interactions with cells in vitro. Given the potential interaction between beta-amyloid and cell-matrix signaling, it is hypothesized that beta-amyloid disrupts normal integrin-mediated signal integration during stem cell differentiation in 3D. Additionally, because disruption of integrin-cell contact can trigger a reactive astrocyte state, it is further hypothesized that aggregated forms of beta-amyloid in the 3D AD-like environment will alter neural stem cell differentiation towards reactive astrocyte phenotypes. To test this hypothesis, in Aim 1 neural stem cell viability will be examined in the presence of A-beta in 2D vs 3D cultures that contain integrin-binding domains (i.e., collagen) or lack integrin-binding domains (agarose). To ensure that differences between 2D and 3D conditions are not due to differences in mass transfer rates, A-beta transport in these systems will be thoroughly characterized using fluorescence correlation spectroscopy. Then neural stem cell fate will be examined in these environments, and as time allows, a combination of techniques will be used to probe the role of integrin subunits and downstream molecules in the signal transduction pathway in cell fate. Based on these and available literature results, in Aim 2 a mathematical model will be build of A-beta-integrin signal integration that will guide experimental design and help discriminate between competing mechanistic hypotheses. While the ultimate goal of this project is to rigorously test this novel hypothesis, with the one year of funding from this EAGER, the work will focus on completing key underlying experiments that will provide solid preliminary data for a future multi-year proposal.
