title: Integrating Genome-Wide Association Study and Brain Expression Data Highlights Cell Adhesion Molecules and Purine Metabolism in Alzheimer's Disease.
abstract: Alzheimer's disease (AD) is the most common neurodegenerative disease in the elderly. Recently, genome-wide association studies (GWAS) have been used to investigate AD pathogenesis. However, a large proportion of AD heritability has yet to be explained. We previously identified the cell adhesion molecule (CAM) pathway as a consistent signal in two AD GWAS. However, it is unclear whether CAM is present in the Genetic and Environmental Risk for Alzheimer's Disease Consortium (GERAD) GWAS and brain expression GWAS. Meanwhile, we think integrating AD GWAS and AD brain expression datasets may provide complementary information to identify important pathways involved in AD. Here, we conducted a systems analysis using (1) KEGG pathways, (2) large-scale AD GWAS from GERAD (n = 11,789), (3) two brain expression GWAS datasets (n = 399) from the AD cerebellum and temporal cortex, and (4) previous results from pathway analysis of AD GWAS. Our results indicate that (1) CAM is a consistent signal in five AD GWAS; (2) CAM is the most significant signal in AD; (3) we confirmed previous AD risk pathways related to immune system and diseases, and cardiovascular disease, etc.; and (4) we highlighted the purine metabolism pathway in AD for the first time. We believe that our results may advance our understanding of AD mechanisms and will be very informative for future genetic studies in AD.
authors.affiliation: Department of Orthopedic Surgery, Beijing Army General Hospital, Clinical Medicine College of Third Military Medical University, No. 5 Nanmencang, Dongcheng District, Beijing, 100700, China.
authors.forename: Zimin
authors.initials: Z
authors.lastname: Xiang
authors.forename: Meiling
authors.initials: M
authors.lastname: Xu
authors.forename: Mingzhi
authors.initials: M
authors.lastname: Liao
authors.forename: Yongshuai
authors.initials: Y
authors.lastname: Jiang
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Jiang
authors.forename: Rennan
authors.initials: R
authors.lastname: Feng
authors.forename: Liangcai
authors.initials: L
authors.lastname: Zhang
authors.forename: Guoda
authors.initials: G
authors.lastname: Ma
authors.forename: Guangyu
authors.initials: G
authors.lastname: Wang
authors.forename: Zugen
authors.initials: Z
authors.lastname: Chen
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao
authors.forename: Tiansheng
authors.initials: T
authors.lastname: Sun
authors.forename: Keshen
authors.initials: K
authors.lastname: Li
authors.forename: Guiyou
authors.initials: G
authors.lastname: Liu
mesh_terms: D000544:Alzheimer Disease / Q000235:genetics* / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000378:metabolism; D030541:Databases, Genetic; D005786:Gene Expression Regulation; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D006801:Humans; D053858:Metabolic Networks and Pathways; D011687:Purines / Q000378:metabolism*; D012307:Risk Factors
chemical_list: D015815:Cell Adhesion Molecules; D011687:Purines