PROJECT SUMMARY This application is being submitted in response to NOT-AG-23-032. Alzheimer's disease (AD) is a progressive neurodegenerative brain disease and the most common cause of dementia in older adults. So far, no cure has been found for AD yet. The dilemma and hurdles for the treatment of AD are not only limited due to the lack of effective therapeutic molecules but also due to their inability to penetrate the basement membrane of the blood- brain-barrier (BBB) and reach the specific target site to treat the disease. Accumulating evidence supports the coexistence of sarcopenia and cognitive dysfunction with aging. Myokines released from the muscle play a pivotal role in facilitating communication between skeletal muscle and the brain. Consequently, therapies targeting this link associated with AD could potentially ameliorate AD-related cognitive decline. While working on our parent grant, we discovered that extracellular vesicles (EVs) released from muscle progenitor cells generated from induced pluripotent stem cells (iPSC) with givinostat (Givi-MPC) were effective for muscle regeneration during aging. The proteomic profiling revealed that neuropeptides enriched EVs could be important therapeutic target for AD, neurogenesis, and neuroprotection. Recent studies further substantiate this by demonstrating that EVs can readily cross the BBB to deliver bioactive molecules to the central nervous system. Accordingly, we hypothesize that Givi-MPC derived EVs effectively counteract the neurotoxic effects of AD pathology. However, development of AD drugs effective in animal failed to translate into interventions in humans. Therefore, a shift towards a human-relevant preclinical model is imperative in the development of drugs for AD. Organoids emerged as promising preclinical models in reproducing the AD hallmarks including Aβ plaques, neurofibrillary tangles as well as promotion of neurodegenerative inflammation. Thus, we will test the efficacy of EVs from Givi- MPC using AD patient specific iPSC derived cerebral organoids (Aim 1) and 5XFAD transgenic mice (Aim 2). In Aim 1, we will evaluate the therapeutic effect of Givi-MPC derived EVs on Aβ amyloid deposits, neuronal viability, and connectivity in AD cerebral organoids. Additionally, we will employ single cell RNA sequence to reveal the clues for underlying mechanism of protection by EVs. In Aim 2, we will assess AD pathology and cognitive function through systemic delivery of EVs in 5XFAD transgenic mice. Successful completion of this supplement could provide a novel and potentially effective EV-based treatment for AD.