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Browsing by Author "Widaman, Keith F."
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Item Combined neuropathological pathways account for age-related risk of dementia(Wiley, 2018-07) Power, Melinda C.; Mormino, Elizabeth; Soldan, Anja; James, Bryan D.; Yu, Lei; Armstrong, Nicole M.; Bangen, Katherine J.; Delano-Wood, Lisa; Lamar, Melissa; Lim, Yen Ying; Nudelman, Kelly; Zahodne, Laura; Gross, Alden L.; Mungas, Dan; Widaman, Keith F.; Schneider, Julie; Radiology and Imaging Sciences, School of MedicineOBJECTIVE: Our objectives were to characterize the inter-relation of known dementia-related neuropathologies in one comprehensive model and quantify the extent to which accumulation of neuropathologies accounts for the association between age and dementia. METHODS: We used data from 1,362 autopsied participants of three community-based clinicopathological cohorts: the Religious Orders Study, the Rush Memory and Aging Project, and the Minority Aging Research Study. We estimated a series of structural equation models summarizing a priori hypothesized neuropathological pathways between age and dementia risk individually and collectively. RESULTS: At time of death (mean age, 89 years), 44% of our sample had a clinical dementia diagnosis. When considered individually, our vascular, amyloid/tau, neocortical Lewy body, and TAR DNA-binding protein 43 (TDP-43)/hippocampal sclerosis pathology pathways each accounted for a substantial proportion of the association between age and dementia. When considered collectively, the four pathways fully accounted for all variance in dementia risk previously attributable to age. Pathways involving amyloid/tau, neocortical Lewy bodies, and TDP-43/hippocampal sclerosis were interdependent, attributable to the importance of amyloid beta plaques in all three. The importance of the pathways varied, with the vascular pathway accounting for 32% of the association between age and dementia, wheraes the remaining three inter-related degenerative pathways together accounted for 68% (amyloid/tau, 24%; the Lewy body, 1%; and TDP-43/hippocampal sclerosis, 43%). INTERPRETATION: Age-related increases in dementia risk can be attributed to accumulation of multiple pathologies, each of which contributes to dementia risk. Multipronged approaches may be necessary if we are to develop effective therapies.Item Sex differences in the genetic architecture of cognitive resilience to Alzheimer's disease(Oxford University Press, 2022) Eissman, Jaclyn M.; Dumitrescu, Logan; Mahoney, Emily R.; Smith, Alexandra N.; Mukherjee, Shubhabrata; Lee, Michael L.; Scollard, Phoebe; Choi, Seo Eun; Bush, William S.; Engelman, Corinne D.; Lu, Qiongshi; Fardo, David W.; Trittschuh, Emily H.; Mez, Jesse; Kaczorowski, Catherine C.; Hernandez Saucedo, Hector; Widaman, Keith F.; Buckley, Rachel F.; Properzi, Michael J.; Mormino, Elizabeth C.; Yang, Hyun Sik; Harrison, Theresa M.; Hedden, Trey; Nho, Kwangsik; Andrews, Shea J.; Tommet, Douglas; Hadad, Niran; Sanders, R. Elizabeth; Ruderfer, Douglas M.; Gifford, Katherine A.; Zhong, Xiaoyuan; Raghavan, Neha S.; Vardarajan, Badri N.; Alzheimer’s Disease Neuroimaging Initiative (ADNI); Alzheimer’s Disease Genetics Consortium (ADGC); A4 Study Team; Pericak-Vance, Margaret A.; Farrer, Lindsay A.; Wang, Li San; Cruchaga, Carlos; Schellenberg, Gerard D.; Cox, Nancy J.; Haines, Jonathan L.; Keene, C. Dirk; Saykin, Andrew J.; Larson, Eric B.; Sperling, Reisa A.; Mayeux, Richard; Cuccaro, Michael L.; Bennett, David A.; Schneider, Julie A.; Crane, Paul K.; Jefferson, Angela L.; Hohman, Timothy J.; Radiology and Imaging Sciences, School of MedicineApproximately 30% of elderly adults are cognitively unimpaired at time of death despite the presence of Alzheimer's disease neuropathology at autopsy. Studying individuals who are resilient to the cognitive consequences of Alzheimer's disease neuropathology may uncover novel therapeutic targets to treat Alzheimer's disease. It is well established that there are sex differences in response to Alzheimer's disease pathology, and growing evidence suggests that genetic factors may contribute to these differences. Taken together, we sought to elucidate sex-specific genetic drivers of resilience. We extended our recent large scale genomic analysis of resilience in which we harmonized cognitive data across four cohorts of cognitive ageing, in vivo amyloid PET across two cohorts, and autopsy measures of amyloid neuritic plaque burden across two cohorts. These data were leveraged to build robust, continuous resilience phenotypes. With these phenotypes, we performed sex-stratified [n (males) = 2093, n (females) = 2931] and sex-interaction [n (both sexes) = 5024] genome-wide association studies (GWAS), gene and pathway-based tests, and genetic correlation analyses to clarify the variants, genes and molecular pathways that relate to resilience in a sex-specific manner. Estimated among cognitively normal individuals of both sexes, resilience was 20-25% heritable, and when estimated in either sex among cognitively normal individuals, resilience was 15-44% heritable. In our GWAS, we identified a female-specific locus on chromosome 10 [rs827389, β (females) = 0.08, P (females) = 5.76 × 10-09, β (males) = -0.01, P(males) = 0.70, β (interaction) = 0.09, P (interaction) = 1.01 × 10-04] in which the minor allele was associated with higher resilience scores among females. This locus is located within chromatin loops that interact with promoters of genes involved in RNA processing, including GATA3. Finally, our genetic correlation analyses revealed shared genetic architecture between resilience phenotypes and other complex traits, including a female-specific association with frontotemporal dementia and male-specific associations with heart rate variability traits. We also observed opposing associations between sexes for multiple sclerosis, such that more resilient females had a lower genetic susceptibility to multiple sclerosis, and more resilient males had a higher genetic susceptibility to multiple sclerosis. Overall, we identified sex differences in the genetic architecture of resilience, identified a female-specific resilience locus and highlighted numerous sex-specific molecular pathways that may underly resilience to Alzheimer's disease pathology. This study illustrates the need to conduct sex-aware genomic analyses to identify novel targets that are unidentified in sex-agnostic models. Our findings support the theory that the most successful treatment for an individual with Alzheimer's disease may be personalized based on their biological sex and genetic context.