ABSTRACT
Neurodegenerative diseases (NDDs) remain a global health challenge. Previous studies have reported potential links between environmental factors and NDDs, however, findings remain controversial across studies and elusive to be interpreted as evidence of robust causal associations. In this study, we comprehensively explored the causal associations of the common environmental factors with major NDDs including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS), based on updated large-scale genome-wide association study data through two-sample Mendelian randomization (MR) approach. Our results indicated that, overall, 28 significant sets of exposure-outcome causal association evidence were detected, 12 of which were previously underestimated and newly identified, including average weekly beer plus cider intake, strenuous sports or other exercises, diastolic blood pressure, and body fat percentage with AD, alcohol intake frequency with PD, apolipoprotein B, systolic blood pressure, and forced expiratory volume in 1â¯s (FEV1) with ALS, and alcohol intake frequency, hip circumference, forced vital capacity, and FEV1 with MS. Moreover, the causal effects of several environmental factors on NDDs were found to overlap. From a triangulation perspective, our investigation provided insights into understanding the associations of environmental factors with NDDs, providing causality-oriented evidence to establish the risk profile of NDDs.
Subject(s)
Alzheimer Disease , Amyotrophic Lateral Sclerosis , Exposome , Multiple Sclerosis , Parkinson Disease , Humans , Amyotrophic Lateral Sclerosis/genetics , Genome-Wide Association Study , Mendelian Randomization Analysis , Alzheimer Disease/genetics , Multiple Sclerosis/geneticsABSTRACT
Alzheimer's disease (AD) remains a global health challenge. Previous studies have reported linkages between AD and multiple behavioural risk exposures, however, the underlying biological mechanisms and crucial genes of gene expression patterns driven by behavioural risks on the onset or progression of AD remains ambiguous. In this study, we performed an integrated analysis on the influence of behavioural risks including smoking, excessive alcohol consumption, physical inactivity, and non-healthy dietary pattern on AD with a comprehensive strategy. Our results demonstrated that multiple behavioural risk exposures could independently or collectively influence diverse hierarchical levels of gene expression patterns through multiple biological mechanisms such as Wnt, mitogen-activated protein kinase (MAPK), AMP-activated protein kinase (AMPK), nuclear factor (NF)-κB, phosphatidylinositol 3-kinase (PI3K)-Akt, and insulin (INS) signalling pathways-mediated pathological processes, thereby prodromally or intermediately impacting AD. Our study provided insights into understanding the association of behavioural risk exposures with AD and informative support for further studies.
Subject(s)
Alzheimer Disease , Humans , Alzheimer Disease/metabolism , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol 3-Kinases/metabolism , Signal Transduction/genetics , Insulin/metabolism , Gene ExpressionABSTRACT
BACKGROUND: Dementia, mainly Alzheimer's disease (AD) and vascular dementia (VaD), remains a global health challenge. Previous studies have demonstrated the benefits of acupuncture therapy (AT) in improving dementia. Nevertheless, the therapeutic targets and integrated biological mechanisms involved remain ambiguous. OBJECTIVE: To identify therapeutic targets and biological mechanisms of AT in treating dementia by integrated analysis strategy. METHODS: By the identification of differentially expressed genes (DEGs) of AD, VaD, and molecular targets of AT active components, the acupuncture therapeutic targets associated with the biological response to AD and VaD were extracted. Therapeutic targets-based functional enrichment analysis was conducted, and multiple networks were constructed. AT-therapeutic crucial targets were captured by weighted gene co-expression network analysis (WGCNA). The interactions between crucial targets with AT active components were verified by molecular docking. RESULTS: Our results demonstrated that 132 and 76 acupuncture therapeutic targets were associated with AD and VaD. AT-therapeutic crucial targets including 58 for AD and 24 for VaD were captured by WGCNA, with 11 in shared, including NMU, GRP, TAC1, ADRA1D, and SST. In addition, 35 and 14 signaling pathways were significantly enriched by functional enrichment analysis, with 6 mutual pathways including neuroactive ligand-receptor interaction, GABAergic synapse, calcium signaling pathway, cAMP signaling pathway, chemokine signaling pathway, and inflammatory mediator regulation of TRP channels. CONCLUSION: The improvement of AD and VaD by AT was associated with modulation of synaptic function, immunity, inflammation, and apoptosis. Our study clarified the therapeutic targets of AT on dementia, providing valuable clues for complementing and combining pharmacotherapy.