Browsing by Author "Au, Rhoda"

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    A genome-wide search for pleiotropy in more than 100,000 harmonized longitudinal cognitive domain scores
    (BMC, 2023-06-22) Kang, Moonil; Ang, Ting Fang Alvin; Devine, Sherral A.; Sherva, Richard; Mukherjee, Shubhabrata; Trittschuh, Emily H.; Gibbons, Laura E.; Scollard, Phoebe; Lee, Michael; Choi, Seo-Eun; Klinedinst, Brandon; Nakano, Connie; Dumitrescu, Logan C.; Durant, Alaina; Hohman, Timothy J.; Cuccaro, Michael L.; Saykin, Andrew J.; Kukull, Walter A.; Bennett, David A.; Wang, Li-San; Mayeux, Richard P.; Haines, Jonathan L.; Pericak-Vance, Margaret A.; Schellenberg, Gerard D.; Crane, Paul K.; Au, Rhoda; Lunetta, Kathryn L.; Mez, Jesse B.; Farrer, Lindsay A.; Radiology and Imaging Sciences, School of Medicine
    Background: More than 75 common variant loci account for only a portion of the heritability for Alzheimer's disease (AD). A more complete understanding of the genetic basis of AD can be deduced by exploring associations with AD-related endophenotypes. Methods: We conducted genome-wide scans for cognitive domain performance using harmonized and co-calibrated scores derived by confirmatory factor analyses for executive function, language, and memory. We analyzed 103,796 longitudinal observations from 23,066 members of community-based (FHS, ACT, and ROSMAP) and clinic-based (ADRCs and ADNI) cohorts using generalized linear mixed models including terms for SNP, age, SNP × age interaction, sex, education, and five ancestry principal components. Significance was determined based on a joint test of the SNP's main effect and interaction with age. Results across datasets were combined using inverse-variance meta-analysis. Genome-wide tests of pleiotropy for each domain pair as the outcome were performed using PLACO software. Results: Individual domain and pleiotropy analyses revealed genome-wide significant (GWS) associations with five established loci for AD and AD-related disorders (BIN1, CR1, GRN, MS4A6A, and APOE) and eight novel loci. ULK2 was associated with executive function in the community-based cohorts (rs157405, P = 2.19 × 10-9). GWS associations for language were identified with CDK14 in the clinic-based cohorts (rs705353, P = 1.73 × 10-8) and LINC02712 in the total sample (rs145012974, P = 3.66 × 10-8). GRN (rs5848, P = 4.21 × 10-8) and PURG (rs117523305, P = 1.73 × 10-8) were associated with memory in the total and community-based cohorts, respectively. GWS pleiotropy was observed for language and memory with LOC107984373 (rs73005629, P = 3.12 × 10-8) in the clinic-based cohorts, and with NCALD (rs56162098, P = 1.23 × 10-9) and PTPRD (rs145989094, P = 8.34 × 10-9) in the community-based cohorts. GWS pleiotropy was also found for executive function and memory with OSGIN1 (rs12447050, P = 4.09 × 10-8) and PTPRD (rs145989094, P = 3.85 × 10-8) in the community-based cohorts. Functional studies have previously linked AD to ULK2, NCALD, and PTPRD. Conclusion: Our results provide some insight into biological pathways underlying processes leading to domain-specific cognitive impairment and AD, as well as a conduit toward a syndrome-specific precision medicine approach to AD. Increasing the number of participants with harmonized cognitive domain scores will enhance the discovery of additional genetic factors of cognitive decline leading to AD and related dementias.
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    APOE genotype-specific methylation patterns are linked to Alzheimer disease pathology and estrogen response
    (Springer Nature, 2024-02-29) Panitch, Rebecca; Sahelijo, Nathan; Hu, Junming; Nho, Kwangsik; Bennett, David A.; Lunetta, Kathryn L.; Au, Rhoda; Stein, Thor D.; Farrer, Lindsay A.; Jun, Gyungah R.; Radiology and Imaging Sciences, School of Medicine
    The joint effects of APOE genotype and DNA methylation on Alzheimer disease (AD) risk is relatively unknown. We conducted genome-wide methylation analyses using 2,021 samples in blood (91 AD cases, 329 mild cognitive impairment, 1,391 controls) and 697 samples in brain (417 AD cases, 280 controls). We identified differentially methylated levels in AD compared to controls in an APOE genotype-specific manner at 25 cytosine-phosphate-guanine (CpG) sites in brain and 36 CpG sites in blood. Additionally, we identified seven CpG sites in the APOE region containing TOMM40, APOE, and APOC1 genes with P < 5 × 10-8 between APOE ε4 carriers and non-carriers in brain or blood. In brain, the most significant CpG site hypomethylated in ε4 carriers compared to non-carriers was from the TOMM40 in the total sample, while most of the evidence was derived from AD cases. However, the CpG site was not significantly modulating expression of these three genes in brain. Three CpG sites from the APOE were hypermethylated in APOE ε4 carriers in brain or blood compared in ε4 non-carriers and nominally significant with APOE expression in brain. Three CpG sites from the APOC1 were hypermethylated in blood, which one of the 3 CpG sites significantly lowered APOC1 expression in blood using all subjects or ε4 non-carriers. Co-methylation network analysis in blood and brain detected eight methylation networks associated with AD and APOE ε4 status. Five of the eight networks included genes containing network CpGs that were significantly enriched for estradiol perturbation, where four of the five networks were enriched for the estrogen response pathway. Our findings provide further evidence of the role of APOE genotype on methylation levels associated with AD, especially linked to estrogen response pathway.
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    Asian Cohort for Alzheimer's Disease (ACAD) pilot study on genetic and non-genetic risk factors for Alzheimer's disease among Asian Americans and Canadians
    (Wiley, 2024) Ho, Pei-Chuan; Yu, Wai Haung; Tee, Boon Lead; Lee, Wan-Ping; Li, Clara; Gu, Yian; Yokoyama, Jennifer S.; Reyes-Dumeyer, Dolly; Choi, Yun-Beom; Yang, Hyun-Sik; Vardarajan, Badri N.; Tzuang, Marian; Lieu, Kevin; Lu, Anna; Faber, Kelley M.; Potter, Zoë D.; Revta, Carolyn; Kirsch, Maureen; McCallum, Jake; Mei, Diana; Booth, Briana; Cantwell, Laura B.; Chen, Fangcong; Chou, Sephera; Clark, Dewi; Deng, Michelle; Hong, Ting Hei; Hwang, Ling-Jen; Jiang, Lilly; Joo, Yoonmee; Kang, Younhee; Kim, Ellen S.; Kim, Hoowon; Kim, Kyungmin; Kuzma, Amanda B.; Lam, Eleanor; Lanata, Serggio C.; Lee, Kunho; Li, Donghe; Li, Mingyao; Li, Xiang; Liu, Chia-Lun; Liu, Collin; Liu, Linghsi; Lupo, Jody-Lynn; Nguyen, Khai; Pfleuger, Shannon E.; Qian, James; Qian, Winnie; Ramirez, Veronica; Russ, Kristen A.; Seo, Eun Hyun; Song, Yeunjoo E.; Tartaglia, Maria Carmela; Tian, Lu; Torres, Mina; Vo, Namkhue; Wong, Ellen C.; Xie, Yuan; Yau, Eugene B.; Yi, Isabelle; Yu, Victoria; Zeng, Xiaoyi; St. George-Hyslop, Peter; Au, Rhoda; Schellenberg, Gerard D.; Dage, Jeffrey L.; Varma, Rohit; Hsiung, Ging-Yuek R.; Rosen, Howard; Henderson, Victor W.; Foroud, Tatiana; Kukull, Walter A.; Peavy, Guerry M.; Lee, Haeok; Feldman, Howard H.; Mayeux, Richard; Chui, Helena; Jun, Gyungah R.; Ta Park, Van M.; Chow, Tiffany W.; Wang, Li-San; Medical and Molecular Genetics, School of Medicine
    Introduction: Clinical research in Alzheimer's disease (AD) lacks cohort diversity despite being a global health crisis. The Asian Cohort for Alzheimer's Disease (ACAD) was formed to address underrepresentation of Asians in research, and limited understanding of how genetics and non-genetic/lifestyle factors impact this multi-ethnic population. Methods: The ACAD started fully recruiting in October 2021 with one central coordination site, eight recruitment sites, and two analysis sites. We developed a comprehensive study protocol for outreach and recruitment, an extensive data collection packet, and a centralized data management system, in English, Chinese, Korean, and Vietnamese. Results: ACAD has recruited 606 participants with an additional 900 expressing interest in enrollment since program inception. Discussion: ACAD's traction indicates the feasibility of recruiting Asians for clinical research to enhance understanding of AD risk factors. ACAD will recruit > 5000 participants to identify genetic and non-genetic/lifestyle AD risk factors, establish blood biomarker levels for AD diagnosis, and facilitate clinical trial readiness. Highlights: The Asian Cohort for Alzheimer's Disease (ACAD) promotes awareness of under-investment in clinical research for Asians. We are recruiting Asian Americans and Canadians for novel insights into Alzheimer's disease. We describe culturally appropriate recruitment strategies and data collection protocol. ACAD addresses challenges of recruitment from heterogeneous Asian subcommunities. We aim to implement a successful recruitment program that enrolls across three Asian subcommunities.
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    Designing the next-generation clinical care pathway for Alzheimer’s disease
    (Springer Nature, 2022) Hampel, Harald; Au, Rhoda; Mattke, Soeren; van der Flier, Wiesje M.; Aisen, Paul; Apostolova, Liana; Chen, Christopher; Cho, Min; De Santi, Susan; Gao, Peng; Iwata, Atsushi; Kurzman, Ricky; Saykin, Andrew J.; Teipel, Stefan; Vellas, Bruno; Vergallo, Andrea; Wang, Huali; Cummings, Jeffrey; Neurology, School of Medicine
    The reconceptualization of Alzheimer's disease (AD) as a clinical and biological construct has facilitated the development of biomarker-guided, pathway-based targeted therapies, many of which have reached late-stage development with the near-term potential to enter global clinical practice. These medical advances mark an unprecedented paradigm shift and requires an optimized global framework for clinical care pathways for AD. In this Perspective, we describe the blueprint for transitioning from the current, clinical symptom-focused and inherently late-stage diagnosis and management of AD to the next-generation pathway that incorporates biomarker-guided and digitally facilitated decision-making algorithms for risk stratification, early detection, timely diagnosis, and preventative or therapeutic interventions. We address critical and high-priority challenges, propose evidence-based strategic solutions, and emphasize that the perspectives of affected individuals and care partners need to be considered and integrated.
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    Protein phosphatase 2A and complement component 4 are linked to the protective effect of APOE ɛ2 for Alzheimer's disease
    (Wiley, 2022) Jun, Gyungah R.; You, Yang; Zhu, Congcong; Meng, Gaoyuan; Chung, Jaeyoon; Panitch, Rebecca; Hu, Junming; Xia, Weiming; The Alzheimer’s Disease Genetics Consortium; Bennett, David A.; Foroud, Tatiana M.; Wang, Li-San; Haines, Jonathan L.; Mayeux, Richard; Pericak-Vance, Margaret A.; Schellenberg, Gerard D.; Au, Rhoda; Lunetta, Kathryn L.; Ikezu, Tsuneya; Stein, Thor D.; Farrer, Lindsay A.; Medical and Molecular Genetics, School of Medicine
    Introduction: The apolipoprotein E (APOE) ɛ2 allele reduces risk against Alzheimer's disease (AD) but mechanisms underlying this effect are largely unknown. Methods: We conducted a genome-wide association study for AD among 2096 ɛ2 carriers. The potential role of the top-ranked gene and complement 4 (C4) proteins, which were previously linked to AD in ɛ2 carriers, was investigated using human isogenic APOE allele-specific induced pluripotent stem cell (iPSC)-derived neurons and astrocytes and in 224 neuropathologically examined human brains. Results: PPP2CB rs117296832 was the second most significantly associated single nucleotide polymorphism among ɛ2 carriers (P = 1.1 × 10-7 ) and the AD risk allele increased PPP2CB expression in blood (P = 6.6 × 10-27 ). PPP2CB expression was correlated with phosphorylated tau231/total tau ratio (P = .01) and expression of C4 protein subunits C4A/B (P = 2.0 × 10-4 ) in the iPSCs. PPP2CB (subunit of protein phosphatase 2A) and C4b protein levels were correlated in brain (P = 3.3 × 10-7 ). Discussion: PP2A may be linked to classical complement activation leading to AD-related tau pathology.
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    Protein phosphatase 2A and complement component 4 are linked to the protective effect of APOE ɛ2 for Alzheimer's disease
    (Wiley, 2022-11) Jun, Gyungah R.; You, Yang; Zhu, Congcong; Meng, Gaoyuan; Chung, Jaeyoon; Panitch, Rebecca; Hu, Junming; Xia, Weiming; The Alzheimer's Disease Genetics Consortium; Bennett, David A.; Foroud, Tatiana M.; Wang, Li-San; Haines, Jonathan L.; Mayeux, Richard; Pericak-Vance, Margaret A.; Schellenberg, Gerard D.; Au, Rhoda; Lunetta, Kathryn L.; Ikezu, Tsuneya; Stein, Thor D.; Farrer, Lindsay A.; Medical and Molecular Genetics, School of Medicine
    Introduction The apolipoprotein E (APOE) ɛ2 allele reduces risk against Alzheimer's disease (AD) but mechanisms underlying this effect are largely unknown. Methods We conducted a genome‐wide association study for AD among 2096 ɛ2 carriers. The potential role of the top‐ranked gene and complement 4 (C4) proteins, which were previously linked to AD in ɛ2 carriers, was investigated using human isogenic APOE allele‐specific induced pluripotent stem cell (iPSC)–derived neurons and astrocytes and in 224 neuropathologically examined human brains. Results PPP2CB rs117296832 was the second most significantly associated single nucleotide polymorphism among ɛ2 carriers (P = 1.1 × 10−7) and the AD risk allele increased PPP2CB expression in blood (P = 6.6 × 10−27). PPP2CB expression was correlated with phosphorylated tau231/total tau ratio (P = .01) and expression of C4 protein subunits C4A/B (P = 2.0 × 10−4) in the iPSCs. PPP2CB (subunit of protein phosphatase 2A) and C4b protein levels were correlated in brain (P = 3.3 × 10−7). Discussion PP2A may be linked to classical complement activation leading to AD‐related tau pathology.