Neurobiological Role of MicroRNA in Alzheimer's - Our goal is to identify mechanisms leading to neurodegeneration in Alzheimer's disease (AD). We will study the regulation of amyloid-β precursor protein (APP), microtubule-associated protein tau (MAPT), −Synuclein (SNCA), and RE1-Silencing Transcription Factor (REST). This proposal will test miR153 as a 'regulator of the regulators'. We have established that miR153 regulates the translation of important AD-associated mRNAs for APP, SNCA, and REST via the untranslated region (UTR). We propose testing the hypothesis that miR153 serves as a nexus regulator of multiple AD-related proteins and control neuronal survival. This proposal will significantly advance the understanding of miR153's role in regulating proteins related to neurodegeneration. SA1. Analyze miR153 interacts with target sites in REST-153 network (R-153net) partner mRNAs. The proteins REST, APP, tau, IL1α, and IL6 play critical roles in AD. A master regulator that controls such protein levels could be a vital tool to prevent AD-related neurotoxicity. We will test the activity of miR153 on multiple mRNA-fused reporter clones based on the mRNA sequence of selected genes. We expect miR153 treatments will silence predicted target sites, and miRNA treatment will further alter protein levels in cell cultures. SA2. Test miR153 perturbs expression of the R-153net and cell health and growth. We will define the neurobiology of miR153's interactions, including reactive oxidizing species (ROS). We will establish effects on native protein levels and cell survival. Identifying the roles of miRNA-mediated regulation of the R-153net will elucidate miRNA-dependent mechanisms to enhance cell vitality. We expect that miR153 interacts with overall cell health, and these studies will reveal mechanisms for miR153 function in cell survival. SA3. Measure miR153 treatment alters the R-153net in induced pluripotent stem cells (iPSC). We will test the effects of miR153 treatment in differentiated iPSC from normal and AD donors. We expect that miR153 will alter R-153net levels and cell vitality and morphology. Forking iPSC cultures into neurons, glia, and mixed-type cell induction will allow for explicitly measuring effects in each of the major brain cell types. SA4. Assess miR153 is dysregulated in AD stage and brain region-specific manners. We will test and model miR153, mRNA, and protein levels in AD, MCI, and control human brain samples, along with APOE, sex, and age vs. disease progression. We expect levels of miR153 and R-153net proteins and mRNAs to vary in progression-dependent manners. Our results will predict the risk associated with R-153net member levels. SA5. Identify SNPs near MIR153 genes associate with altered CSF Aβ and phospho-tau levels. We will identify the effects of SNPs close to the MIR153-1 and -2 genes. We will investigate large-scale genomic data for SNP associations with AD endophenotypes, which will provide predictive AD biomarkers. Our studies in cell cultures, iPSCs, miRNA expression in human brains, and identifying SNPs near MIR153 genes will establish their relationships to AD and lead to novel diagnostic and therapeutic strategies.
