Browsing by Author "Chung, Jaeyoon"
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Item Alzheimer’s Disease Heterogeneity Explained by Polygenic Risk Scores Derived from Brain Transcriptomic Profiles(Wiley, 2023) Chung, Jaeyoon; Sahelijo, Nathan; Maruyama, Toru; Hu, Junming; Panitch, Rebecca; Xia, Weiming; Mez, Jesse; Stein, Thor D.; Alzheimer’s Disease Neuroimaging Initiative; Saykin, Andrew J.; Takeyama, Haruko; Farrer, Lindsay A.; Crane, Paul K.; Nho, Kwangsik; Jun, Gyungah R.; Radiology and Imaging Sciences, School of MedicineIntroduction: Alzheimer's disease (AD) is heterogeneous, both clinically and neuropathologically. We investigated whether polygenic risk scores (PRSs) integrated with transcriptome profiles from AD brains can explain AD clinical heterogeneity. Methods: We conducted co-expression network analysis and identified gene sets (modules) that were preserved in three AD transcriptome datasets and associated with AD-related neuropathological traits including neuritic plaques (NPs) and neurofibrillary tangles (NFTs). We computed the module-based PRSs (mbPRSs) for each module and tested associations with mbPRSs for cognitive test scores, cognitively defined AD subgroups, and brain imaging data. Results: Of the modules significantly associated with NPs and/or NFTs, the mbPRSs from two modules (M6 and M9) showed distinct associations with language and visuospatial functioning, respectively. They matched clinical subtypes and brain atrophy at specific regions. Discussion: Our findings demonstrate that polygenic profiling based on co-expressed gene sets can explain heterogeneity in AD patients, enabling genetically informed patient stratification and precision medicine in AD. Highlights: Co-expression gene-network analysis in Alzheimer's disease (AD) brains identified gene sets (modules) associated with AD heterogeneity. AD-associated modules were selected when genes in each module were enriched for neuritic plaques and neurofibrillary tangles. Polygenic risk scores from two selected modules were linked to the matching cognitively defined AD subgroups (language and visuospatial subgroups). Polygenic risk scores from the two modules were associated with cognitive performance in language and visuospatial domains and the associations were confirmed in regional-specific brain atrophy data.Item New insights into the genetic etiology of Alzheimer's disease and related dementias(Springer Nature, 2022) Bellenguez, Céline; Küçükali, Fahri; Jansen, Iris E.; Kleineidam, Luca; Moreno-Grau, Sonia; Amin, Najaf; Naj, Adam C.; Campos-Martin, Rafael; Grenier-Boley, Benjamin; Andrade, Victor; Holmans, Peter A.; Boland, Anne; Damotte, Vincent; van der Lee, Sven J.; Costa, Marcos R.; Kuulasmaa, Teemu; Yang, Qiong; de Rojas, Itziar; Bis, Joshua C.; Yaqub, Amber; Prokic, Ivana; Chapuis, Julien; Ahmad, Shahzad; Giedraitis, Vilmantas; Aarsland, Dag; Garcia-Gonzalez, Pablo; Abdelnour, Carla; Alarcón-Martín, Emilio; Alcolea, Daniel; Alegret, Montserrat; Alvarez, Ignacio; Álvarez, Victoria; Armstrong, Nicola J.; Tsolaki, Anthoula; Antúnez, Carmen; Appollonio, Ildebrando; Arcaro, Marina; Archetti, Silvana; Arias Pastor, Alfonso; Arosio, Beatrice; Athanasiu, Lavinia; Bailly, Henri; Banaj, Nerisa; Baquero, Miquel; Barral, Sandra; Beiser, Alexa; Belén Pastor, Ana; Below, Jennifer E.; Benchek, Penelope; Benussi, Luisa; Berr, Claudine; Besse, Céline; Bessi, Valentina; Binetti, Giuliano; Bizarro, Alessandra; Blesa, Rafael; Boada, Mercè; Boerwinkle, Eric; Borroni, Barbara; Boschi, Silvia; Bossù, Paola; Bråthen, Geir; Bressler, Jan; Bresner, Catherine; Brodaty, Henry; Brookes, Keeley J.; Brusco, Luis Ignacio; Buiza-Rueda, Dolores; Bûrger, Katharina; Burholt, Vanessa; Bush, William S.; Calero, Miguel; Cantwell, Laura B.; Chene, Geneviève; Chung, Jaeyoon; Cuccaro, Michael L.; Carracedo, Ángel; Cecchetti, Roberta; Cervera-Carles, Laura; Charbonnier, Camille; Chen, Hung-Hsin; Chillotti, Caterina; Ciccone, Simona; Claassen, Jurgen A. H. R.; Clark, Christopher; Conti, Elisa; Corma-Gómez, Anaïs; Costantini, Emanuele; Custodero, Carlo; Daian, Delphine; Dalmasso, Maria Carolina; Daniele, Antonio; Dardiotis, Efthimios; Dartigues, Jean-François; de Deyn, Peter Paul; de Paiva Lopes, Katia; de Witte, Lot D.; Debette, Stéphanie; Deckert, Jürgen; Del Ser, Teodoro; Denning, Nicola; DeStefano, Anita; Dichgans, Martin; Diehl-Schmid, Janine; Diez-Fairen, Mónica; Dionigi Rossi, Paolo; Djurovic, Srdjan; Duron, Emmanuelle; Düzel, Emrah; Dufouil, Carole; Eiriksdottir, Gudny; Engelborghs, Sebastiaan; Escott-Price, Valentina; Espinosa, Ana; Ewers, Michael; Faber, Kelley M.; Fabrizio, Tagliavini; Fallgaard Nielsen, Sune; Fardo, David W.; Farotti, Lucia; Fenoglio, Chiara; Fernández-Fuertes, Marta; Ferrari, Raffaele; Ferreira, Catarina B.; Ferri, Evelyn; Fin, Bertrand; Fischer, Peter; Fladby, Tormod; Fließbach, Klaus; Fongang, Bernard; Fornage, Myriam; Fortea, Juan; Foroud, Tatiana M.; Fostinelli, Silvia; Fox, Nick C.; Franco-Macías, Emlio; Bullido, María J.; Frank-García, Ana; Froelich, Lutz; Fulton-Howard, Brian; Galimberti, Daniela; García-Alberca, Jose Maria; García-González, Pablo; Garcia-Madrona, Sebastian; Garcia-Ribas, Guillermo; Ghidoni, Roberta; Giegling, Ina; Giorgio, Giaccone; Goate, Alison M.; Goldhardt, Oliver; Gomez-Fonseca, Duber; González-Pérez, Antonio; Graff, Caroline; Grande, Giulia; Green, Emma; Grimmer, Timo; Grünblatt, Edna; Grunin, Michelle; Gudnason, Vilmundur; Guetta-Baranes, Tamar; Haapasalo, Annakaisa; Hadjigeorgiou, Georgios; Haines, Jonathan L.; Hamilton-Nelson, Kara L.; Hampel, Harald; Hanon, Olivier; Hardy, John; Hartmann, Annette M.; Hausner, Lucrezia; Harwood, Janet; Heilmann-Heimbach, Stefanie; Helisalmi, Seppo; Heneka, Michael T.; Hernández, Isabel; Herrmann, Martin J.; Hoffmann, Per; Holmes, Clive; Holstege, Henne; Huerto Vilas, Raquel; Hulsman, Marc; Humphrey, Jack; Jan Biessels, Geert; Jian, Xueqiu; Johansson, Charlotte; Jun, Gyungah R.; Kastumata, Yuriko; Kauwe, John; Kehoe, Patrick G.; Kilander, Lena; Kinhult Ståhlbom, Anne; Kivipelto, Miia; Koivisto, Anne; Kornhuber, Johannes; Kosmidis, Mary H.; Kukull, Walter A.; Kuksa, Pavel P.; Kunkle, Brian W.; Kuzma, Amanda B.; Lage, Carmen; Laukka, Erika J.; Launer, Lenore; Lauria, Alessandra; Lee, Chien-Yueh; Lehtisalo, Jenni; Lerch, Ondrej; Lleó, Alberto; Longstreth, William, Jr.; Lopez, Oscar; Lopez de Munain, Adolfo; Love, Seth; Löwemark, Malin; Luckcuck, Lauren; Lunetta, Kathryn L.; Ma, Yiyi; Macías, Juan; MacLeod, Catherine A.; Maier, Wolfgang; Mangialasche, Francesca; Spallazzi, Marco; Marquié, Marta; Marshall, Rachel; Martin, Eden R.; Martín Montes, Angel; Martínez Rodríguez, Carmen; Masullo, Carlo; Mayeux, Richard; Mead, Simon; Mecocci, Patrizia; Medina, Miguel; Meggy, Alun; Mehrabian, Shima; Mendoza, Silvia; Menéndez-González, Manuel; Mir, Pablo; Moebus, Susanne; Mol, Merel; Molina-Porcel, Laura; Montrreal, Laura; Morelli, Laura; Moreno, Fermin; Morgan, Kevin; Mosley, Thomas; Nöthen, Markus M.; Muchnik, Carolina; Mukherjee, Shubhabrata; Nacmias, Benedetta; Ngandu, Tiia; Nicolas, Gael; Nordestgaard, Børge G.; Olaso, Robert; Orellana, Adelina; Orsini, Michela; Ortega, Gemma; Padovani, Alessandro; Paolo, Caffarra; Papenberg, Goran; Parnetti, Lucilla; Pasquier, Florence; Pastor, Pau; Peloso, Gina; Pérez-Cordón, Alba; Pérez-Tur, Jordi; Pericard, Pierre; Peters, Oliver; Pijnenburg, Yolande A. L.; Pineda, Juan A.; Piñol-Ripoll, Gerard; Pisanu, Claudia; Polak, Thomas; Popp, Julius; Posthuma, Danielle; Priller, Josef; Puerta, Raquel; Quenez, Olivier; Quintela, Inés; Qvist Thomassen, Jesper; Rábano, Alberto; Rainero, Innocenzo; Rajabli, Farid; Ramakers, Inez; Real, Luis M.; Reinders, Marcel J. T.; Reitz, Christiane; Reyes-Dumeyer, Dolly; Ridge, Perry; Riedel-Heller, Steffi; Riederer, Peter; Roberto, Natalia; Rodriguez-Rodriguez, Eloy; Rongve, Arvid; Rosas Allende, Irene; Rosende-Roca, Maitée; Royo, Jose Luis; Rubino, Elisa; Rujescu, Dan; Sáez, María Eugenia; Sakka, Paraskevi; Saltvedt, Ingvild; Sanabria, Ángela; Sánchez-Arjona, María Bernal; Sanchez-Garcia, Florentino; Sánchez Juan, Pascual; Sánchez-Valle, Raquel; Sando, Sigrid B.; Sarnowski, Chloé; Satizabal, Claudia L.; Scamosci, Michela; Scarmeas, Nikolaos; Scarpini, Elio; Scheltens, Philip; Scherbaum, Norbert; Scherer, Martin; Schmid, Matthias; Schneider, Anja; Schott, Jonathan M.; Selbæk, Geir; Seripa, Davide; Serrano, Manuel; Sha, Jin; Shadrin, Alexey A.; Skrobot, Olivia; Slifer, Susan; Snijders, Gijsje J. L.; Soininen, Hilkka; Solfrizzi, Vincenzo; Solomon, Alina; Song, Yeunjoo; Sorbi, Sandro; Sotolongo-Grau, Oscar; Spalletta, Gianfranco; Spottke, Annika; Squassina, Alessio; Stordal, Eystein; Tartan, Juan Pablo; Tárraga, Lluís; Tesí, Niccolo; Thalamuthu, Anbupalam; Thomas, Tegos; Tosto, Giuseppe; Traykov, Latchezar; Tremolizzo, Lucio; Tybjærg-Hansen, Anne; Uitterlinden, Andre; Ullgren, Abbe; Ulstein, Ingun; Valero, Sergi; Valladares, Otto; Van Broeckhoven, Christine; Vance, Jeffery; Vardarajan, Badri N.; van der Lugt, Aad; Van Dongen, Jasper; van Rooij, Jeroen; van Swieten, John; Vandenberghe, Rik; Verhey, Frans; Vidal, Jean-Sébastien; Vogelgsang, Jonathan; Vyhnalek, Martin; Wagner, Michael; Wallon, David; Wang, Li-San; Wang, Ruiqi; Weinhold, Leonie; Wiltfang, Jens; Windle, Gill; Woods, Bob; Yannakoulia, Mary; Zare, Habil; Zhao, Yi; Zhang, Xiaoling; Zhu, Congcong; Zulaica, Miren; EADB; GR@ACE; DEGESCO; EADI; GERAD; Demgene; FinnGen; ADGC; CHARGE; Farrer, Lindsay A.; Psaty, Bruce M.; Ghanbari, Mohsen; Raj, Towfique; Sachdev, Perminder; Mather, Karen; Jessen, Frank; Ikram, M. Arfan; de Mendonça, Alexandre; Hort, Jakub; Tsolaki, Magda; Pericak-Vance, Margaret A.; Amouyel, Philippe; Williams, Julie; Frikke-Schmidt, Ruth; Clarimon, Jordi; Deleuze, Jean-François; Rossi, Giacomina; Seshadri, Sudha; Andreassen, Ole A.; Ingelsson, Martin; Hiltunen, Mikko; Sleegers, Kristel; Schellenberg, Gerard D.; van Duijn, Cornelia M.; Sims, Rebecca; van der Flier, Wiesje M.; Ruiz, Agustín; Ramirez, Alfredo; Lambert, Jean-Charles; Medical and Molecular Genetics, School of MedicineCharacterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele.Item Novel Alzheimer Disease Risk Loci and Pathways in African American Individuals Using the African Genome Resources Panel(American Medical Association, 2021-01-01) Kunkle, Brian W.; Schmidt, Michael; Klein, Hans-Ulrich; Naj, Adam C.; Hamilton-Nelson, Kara L.; Larson, Eric B.; Evans, Denis A.; De Jager, Phil L.; Crane, Paul K.; Buxbaum, Joe D.; Ertekin-Taner, Nilufer; Go, Rodney C.P.; Obisesan, Thomas O.; Kamboh, Ilyas; Bennett, David A.; Hall, Kathleen S.; Goate, Alison M.; Foroud, Tatiana M.; Martin, Eden R.; Wang, Li-Sao; Byrd, Goldie S.; Farrer, Lindsay A.; Haines, Jonathan L.; Schellenberg, Gerard D.; Mayeux, Richard; Pericak-Vance, Margaret A.; Reitz, Christiane; Graff-Radford, Neill R.; Martinez, Izri; Ayodele, Temitope; Logue, Mark W.; Cantwell, Laura B.; Jean-Francois, Melissa; Kuzma, Amanda B.; Adams, L.D.; Vance, Jeffery M.; Cuccaro, Michael L.; Chung, Jaeyoon; Mez, Jesse; Lunetta, Kathryn L.; Jun, Gyungah R.; Lopez, Oscar L.; Hendrie, Hugh C.; Reiman, Eric M.; Kowall, Neil W.; Leverenz, James B.; Small, Scott A.; Levey, Allan I.; Golde, Todd E.; Saykin, Andrew J.; Starks, Takiyah D.; Albert, Marilyn S.; Hyman, Bradley T.; Petersen, Ronald C.; Sano, Mary; Wisniewski, Thomas; Vassar, Robert; Kaye, Jeffrey A.; Henderson, Victor W.; DeCarli, Charles; LaFerla, Frank M.; Brewer, James B.; Miller, Bruce L.; Swerdlow, Russell H.; Van Eldik, Linda J.; Paulson, Henry L.; Trojanowski, John Q.; Chui, Helena C.; Rosenberg, Roger N.; Craft, Suzanne; Grabowski, Thomas J.; Asthana, Sanjay; Morris, John C.; Strittmatter, Stephen M.; Kukull, Walter A.; Psychiatry, School of MedicineImportance: Compared with non-Hispanic White individuals, African American individuals from the same community are approximately twice as likely to develop Alzheimer disease. Despite this disparity, the largest Alzheimer disease genome-wide association studies to date have been conducted in non-Hispanic White individuals. In the largest association analyses of Alzheimer disease in African American individuals, ABCA7, TREM2, and an intergenic locus at 5q35 were previously implicated. Objective: To identify additional risk loci in African American individuals by increasing the sample size and using the African Genome Resource panel. Design, setting, and participants: This genome-wide association meta-analysis used case-control and family-based data sets from the Alzheimer Disease Genetics Consortium. There were multiple recruitment sites throughout the United States that included individuals with Alzheimer disease and controls of African American ancestry. Analysis began October 2018 and ended September 2019. Main outcomes and measures: Diagnosis of Alzheimer disease. Results: A total of 2784 individuals with Alzheimer disease (1944 female [69.8%]) and 5222 controls (3743 female [71.7%]) were analyzed (mean [SD] age at last evaluation, 74.2 [13.6] years). Associations with 4 novel common loci centered near the intracellular glycoprotein trafficking gene EDEM1 (3p26; P = 8.9 × 10-7), near the immune response gene ALCAM (3q13; P = 9.3 × 10-7), within GPC6 (13q31; P = 4.1 × 10-7), a gene critical for recruitment of glutamatergic receptors to the neuronal membrane, and within VRK3 (19q13.33; P = 3.5 × 10-7), a gene involved in glutamate neurotoxicity, were identified. In addition, several loci associated with rare variants, including a genome-wide significant intergenic locus near IGF1R at 15q26 (P = 1.7 × 10-9) and 6 additional loci with suggestive significance (P ≤ 5 × 10-7) such as API5 at 11p12 (P = 8.8 × 10-8) and RBFOX1 at 16p13 (P = 5.4 × 10-7) were identified. Gene expression data from brain tissue demonstrate association of ALCAM, ARAP1, GPC6, and RBFOX1 with brain β-amyloid load. Of 25 known loci associated with Alzheimer disease in non-Hispanic White individuals, only APOE, ABCA7, TREM2, BIN1, CD2AP, FERMT2, and WWOX were implicated at a nominal significance level or stronger in African American individuals. Pathway analyses strongly support the notion that immunity, lipid processing, and intracellular trafficking pathways underlying Alzheimer disease in African American individuals overlap with those observed in non-Hispanic White individuals. A new pathway emerging from these analyses is the kidney system, suggesting a novel mechanism for Alzheimer disease that needs further exploration. Conclusions and relevance: While the major pathways involved in Alzheimer disease etiology in African American individuals are similar to those in non-Hispanic White individuals, the disease-associated loci within these pathways differ.Item PLXNA4 is associated with Alzheimer disease and modulates tau phosphorylation(Wiley Blackwell (John Wiley & Sons), 2014-09) Jun, Gyungah; Asai, Hirohide; Zeldich, Ella; Drapeau, Elodie; Chen, CiDi; Chung, Jaeyoon; Park, Jong-Ho; Kim, Sehwa; Haroutunian, Vahram; Foroud, Tatiana; Kuwano, Ryozo; Haines, Jonathan L.; Pericak-Vance, Margaret A.; Schellenberg, Gerard D.; Lunetta, Kathryn L.; Kim, Jong-Won; Buxbaum, Joseph D.; Mayeux, Richard; Ikezu, Tsuneya; Abraham, Carmela R.; Farrer, Lindsay A.; Department of Medical & Molecular Genetics, IU School of MedicineOBJECTIVE: Much of the genetic basis for Alzheimer disease (AD) is unexplained. We sought to identify novel AD loci using a unique family-based approach that can detect robust associations with infrequent variants (minor allele frequency < 0.10). METHODS: We conducted a genome-wide association study in the Framingham Heart Study (discovery) and NIA-LOAD (National Institute on Aging-Late-Onset Alzheimer Disease) Study (replication) family-based cohorts using an approach that accounts for family structure and calculates a risk score for AD as the outcome. Links between the most promising gene candidate and AD pathogenesis were explored in silico as well as experimentally in cell-based models and in human brain. RESULTS: Genome-wide significant association was identified with a PLXNA4 single nucleotide polymorphism (rs277470) located in a region encoding the semaphorin-3A (SEMA3A) binding domain (meta-analysis p value [meta-P] = 4.1 × 10(-8) ). A test for association with the entire region was also significant (meta-P = 3.2 × 10(-4) ). Transfection of SH-SY5Y cells or primary rat neurons with full-length PLXNA4 (TS1) increased tau phosphorylation with stimulated by SEMA3A. The opposite effect was observed when cells were transfected with shorter isoforms (TS2 and TS3). However, transfection of any isoform into HEK293 cells stably expressing amyloid β (Aβ) precursor protein (APP) did not result in differential effects on APP processing or Aβ production. Late stage AD cases (n = 9) compared to controls (n = 5) had 1.9-fold increased expression of TS1 in cortical brain tissue (p = 1.6 × 10(-4) ). Expression of TS1 was significantly correlated with the Clinical Dementia Rating score (ρ = 0.75, p = 2.2 × 10(-4) ), plaque density (ρ = 0.56, p = 0.01), and Braak stage (ρ = 0.54, p = 0.02). INTERPRETATION: Our results indicate that PLXNA4 has a role in AD pathogenesis through isoform-specific effects on tau phosphorylation.Item 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 MedicineIntroduction 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.Item 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 MedicineIntroduction: 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.Item Two novel loci, COBL and SLC10A2, for Alzheimer's disease in African Americans(Elsevier, 2017-02) Mez, Jesse; Chung, Jaeyoon; Jun, Gyungah; Kriegel, Joshua; Bourlas, Alexandra P.; Sherva, Richard; Logue, Mark W.; Barnes, Lisa L.; Bennett, David A.; Buxbaum, Joseph D.; Byrd, Goldie S.; Crane, Paul K.; Ertekin-Taner, Nilüfer; Evans, Denis; Fallin, M. Daniele; Foroud, Tatiana; Goate, Alison; Graff-Radford, Neill R.; Hall, Kathleen S.; Kamboh, M. Ilyas; Kukull, Walter A.; Larson, Eric B.; Manly, Jennifer J.; Haines, Jonathan L.; Mayeux, Richard; Pericak-Vance, Margaret A.; Schellenberg, Gerard D.; Lunetta, Kathryn L.; Farrer, Lindsay A.; Department of Medical & Molecular Genetics, IU School of MedicineINTRODUCTION: African Americans' (AAs) late-onset Alzheimer's disease (LOAD) genetic risk profile is incompletely understood. Including clinical covariates in genetic analyses using informed conditioning might improve study power. METHODS: We conducted a genome-wide association study (GWAS) in AAs employing informed conditioning in 1825 LOAD cases and 3784 cognitively normal controls. We derived a posterior liability conditioned on age, sex, diabetes status, current smoking status, educational attainment, and affection status, with parameters informed by external prevalence information. We assessed association between the posterior liability and a genome-wide set of single-nucleotide polymorphisms (SNPs), controlling for APOE and ABCA7, identified previously in a LOAD GWAS of AAs. RESULTS: Two SNPs at novel loci, rs112404845 (P = 3.8 × 10-8), upstream of COBL, and rs16961023 (P = 4.6 × 10-8), downstream of SLC10A2, obtained genome-wide significant evidence of association with the posterior liability. DISCUSSION: An informed conditioning approach can detect LOAD genetic associations in AAs not identified by traditional GWAS.