Friday, April 4, 2025
4/4/2025
TREM2 Genotype-Informed Drug Repurposing and Combination Therapy Design for Alzheimers Disease - PROJECT SUMMARY The cumulative evidence indicates neuro-inflammation play crucial roles in Alzheimer’s disease (AD) and anti- inflammatory agents (i.e., microglia-targeted therapies) show potential treatments for AD. The treatment window for microglia-targeted therapies may at least be open later in AD due to the nature of microglial biology. If amyloid-β is the trigger for AD, and tau is the executioner, then microglia are accelerators of disease progression. Microglia-targeted approaches have a better chance of success in mild to moderate disease compared to anti-amyloid therapies that have to prevent the trigger early in AD. Among the microglial genes, triggering receptor expressed on myeloid cells 2 (TREM2) has received much attention because a hemizygous R47H variant of TREM2 (TREM2R47H) increases the AD risk by 2-7 folds in various populations, including African American. Our preliminary single-nucleus RNA-sequencing (snRNAseq) study identified disease-associated microglia (DAM) with enhanced AD pro-inflammatory signatures (i.e., activation of Akt-signaling) associated with the TREM2R47H variant and pharmacological Akt inhibition reversed the TREM2R47H induced inflammation, showing proof-of-concept of TREM2R47H targeted drug discovery in AD. Using multimodal snRNAseq analysis, we identified two approved anti-inflammatory asthma drugs (fluticasone and mometasone) that were predicted to modulate DAM molecular networks are associated with a reduced incidence of AD in electronic health record (EHR) data of 7 million patients. We therefore posit that understanding how the AD-linked mutations (i.e., TREM2R47H) enhance microglial toxicity could lead to understanding how microglia become maladaptive/toxic and development of microglia-targeted therapeutic strategy for late-onset sporadic AD in general. This application calls for novel microglia-targeted drug repurposing and combination therapies for AD using our well-established multi-omics and deep learning-based EHR approaches, and functional observations in AD patient-induced pluripotent stem cells (iPSCs), cerebral organoids, and mouse models, with three specific Aims. Aim 1 will test the TREM2R47H informed microglia-targeted therapeutic hypothesis for identifying cell type-specific molecular drivers/networks, repurposable drugs, and combination therapies for AD using multi-omics evidence aggregation. These analyses will leverage our existing snRNAseq data (n = 24 TREM2R47H and n = 23 common variant (CV)-TREM2 with matched age, AD pathology and APOE genotypes) and public genomic data from the AD knowledge portal. Aim 2 will identify repurposable drugs and combination therapies using high-throughput EHR-based hypothesis generation and sequential deep learning-based propensity score matching approaches. We will leverage de-identified EHRs from the INSIGHT networks (~11 million patients across New York City’s 5 health systems and the greater metropolitan area). Aim 3 will screen, test and validate drugs using AD patient- derived iPSC lines carrying TREM2R47H in conjunction with cerebral organoid and mouse models. The successful completion of this project will offer a viable strategy to move AD drug repurposing from bench to bedside rapidly. 1
HHS’ Tracking Accountability in Government Grants System (TAGGS) website provides access to detailed descriptions of grants, loans, aggregated direct payments and other types of financial assistance awarded by the HHS Operating Divisions (OPDIVs) and the Office of the Secretary Staff Divisions (STAFFDIVs).