The pathologic mechanisms of cognitive decline in Parkinson's disease (PD) are poorly understood, although Alzheimer's disease (AD) co-pathology plays an important role. Over 80% of people with PD will develop dementia, causing lower quality of life, increased caregiver burden, and worse health outcomes. Symptomatic therapies are only minimally effective, and no disease-modifying therapies exist, which represent major unmet needs. Improving our understanding of the neurobiology of PD dementia (PDD) can elucidate pathways for novel treatment development. Identifying the role of AD genetic risk factors in PDD will broaden our understanding of this disease. We hypothesize that AD genetic risk factors will predict faster cognitive decline, greater tau and amyloid-?42 (A?) deposition as reflected in molecular biomarkers, and more AD co- pathology in PD. Dr. Tropea will leverage multiple existing research cohorts at the University of Pennsylvania, the Pacific Northwest Udall Center (PANUC), who are longstanding UPenn collaborators, and the international Parkinson's Progression Markers marker Initiative (PPMI).
The aims of this proposal are to test whether genetic variants in genome-wide association with risk of AD are associated with 1) longitudinal cognitive decline, 2) a greater degree of neurodegeneration, tau and A? deposition reflected in molecular biomarkers, 3) AD neuropathology in PD. The K23 candidate is an Assistant Professor of Neurology at The University of Pennsylvania. He previously completed a movement disorders fellowship and NINDS T32-supported Masters of Translational Research. He has a history of productivity, having conducted basic and clinical research in neuroscience, recently focusing on PDD. The candidate is committed to a career in translational research and proposes a comprehensive five- year plan of mentorship, formal training, self-directed learning, and research. This K23 award will establish Dr. Tropea as a clinician-scientist with expertise in 1) developing and executing genetic association studies; and 2) understanding common genetic risk between AD and PD. This career development award will support Dr. Tropea's short-term goals, including 1) developing a detailed understanding of genetic association studies and polygenic risk scores in predicting clinical, biomarker, and neuropathological outcomes, 2) acquisition of skills necessary to analyze and interpret complex clinical and genetic data; and 3) developing skills for analyzing biomarker and neuropathology data. Dr. Tropea will meet these objectives under the guidance of a Mentorship Team, including Dr. Alice Chen-Plotkin (primary mentor), a federally-funded clinician-scientist and established mentor, Dr. John Q Trojanowski (co-mentor), a world-renowned expert in the molecular pathology of ageing and neurodegeneration with a distinguished record of faculty mentorship, and Dr Sharon X. Xie, an expert in biostatistics in neurodegeneration. This Award will support Dr. Tropea in his pursuit to develop a career as an independent clinician-scientist, focused on translating biological insights into clinical studies in PD.
Over 80% of people with Parkinson's disease (PD) will develop dementia, causing lower quality of life, increased caregiver burden, and worse health outcomes. Although the pathological mechanisms of dementia in PD are poorly understood, Alzheimer's disease (AD) co-pathology is believed to play an important role. Identifying the impact of AD genetic risk factors in PD dementia (PDD) will broaden our understanding of PDD and open the door to developing therapeutic or preventative approaches targeting AD pathology to reduce the burden of dementia in PD patients.
