👤 Williams Turpin

Allostatic load (AL), an index of cumulative physiological dysregulation from chronic stress, may contribute to Alzheimer's disease (AD) pathophysiology by accelerating brain aging. Higher AL has been associated with AD-related biomarkers, suggesting a mechanistic connection. Lifestyle factors influence both AL and AD vulnerability, but their moderating role in AL-AD biomarker associations remains unclear. We included 111 cognitively unimpaired older adults from the baseline visit of the Age-Well trial. AL was computed as a composite score of 18 biomarkers spanning neuroendocrine, immune, metabolic, cardiovascular-respiratory, and anthropometric systems. Plasma biomarkers included amyloid beta (Aβ)42, Aβ40, phosphorylated-tau (p-tau231), glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL). Physical activity, Mediterranean diet adherence, and cognitive activity were assessed using validated questionnaires. Multiple linear regressions tested associations between AL and (1) AD-related biomarkers and (2) lifestyle factors, as well as their interactions, controlling for age, sex, education, apolipoprotein E ε4 (APOE ε4) status, and glomerular filtration rate (GFR). Higher AL was associated with higher Aβ42/Aβ40 ratio ( Regular physical activity was associated with a weaker relationship between AL and early AD-related biomarkers in this cross-sectional sample. Longitudinal studies should confirm whether maintaining physical activity attenuates stress-related physiological dysregulation and reduces AD vulnerability. Show less

CNS diseases are a prevailing cause of morbidity and mortality worldwide, and are influenced by environmental and biological factors, including genetic risk. Here, we generated genome-wide genetic data on a large cohort of brain tissue donors with in-depth clinical and neuropathological phenotyping, allowing for broad investigations into the risk and mechanisms of these neurological, neurodevelopmental, and psychiatric conditions. This resource consists of 9,663 donors with array-based genotyping and 9,543 donors with whole-genome sequencing completed. The clinical diagnoses of these donors include 148 central nervous system diseases clustered into 15 broad categories by International Classification of Diseases-10 (ICD-10) coding. These donors were collected by six repositories comprising the National Institutes of Health NeuroBioBank, with an average participant age of 60 years. While primarily older individuals of European descent, the cohort also contains younger donors and individuals from non-European backgrounds. Variants were detected in whole-genome sequencing (WGS), normalized and annotated to describe their functional impact, resulting in 171,121,209 unique variants and 1,078,774 non-silent variants. These raw and normalized data have been made available as a neurogenomics resource in the National Institute of Mental Health Data Archive (NIMH NDA) (nda.nih.gov), combined with donor-matched deep demographic and phenotypic data from the NeuroBioBank Portal (neurobiobank.nih.gov). To illustrate applications, we replicated the strong association observed in previous studies between pathogenic CAG nucleotide repeat expansions in the HTT gene with the clinical diagnosis of Huntington's disease, as well as associations of the APOE gene with Alzheimer's disease, and examined the association of polygenic risk scores with the three most common disease diagnoses in the cohort. Show less

Microbial-derived bile acids can modulate host gene expression, and their faecal abundance is decreased in active inflammatory bowel disease [IBD]. We analysed the impact of endoscopic inflammation on microbial genes involved in bile acid biotransformation, and their interaction with host transcriptome in the intestinal mucosa of IBD patients. Endoscopic mucosal biopsies were collected from non-inflamed and inflamed terminal ileum, ascending and sigmoid colon of IBD patients. Prediction of imputed metagenome functional content from 16S rRNA profile and real-time quantitative polymerase chain reaction [qPCR] were utsed to assess microbial bile acid biotransformation gene abundance, and RNA-seq was used for host transcriptome analysis. Linear regression and partial Spearman correlation accounting for age, sex, and IBD type were used to assess the association between microbial genes, inflammation, and host transcriptomics in each biopsy location. A Bayesian network [BN] analysis was fitted to infer the direction of interactions between IBD traits and microbial and host genes. The inferred microbial gene pathway involved in secondary bile acid biosynthesis [ko00121 pathway] was depleted in inflamed terminal ileum of IBD patients compared with non-inflamed tissue. In non-inflamed sigmoid colon, the relative abundance of bile acid-inducible [baiCD] microbial genes was positively correlated with the host Angiopoietin-like 4 [Angptl4] gene expression. The BN analysis suggests that the microbial baiCD gene abundance could affect Angptl4 expression, and this interaction appears to be lost in the presence of inflammation. Endoscopic inflammation affects the abundance of crucial microbial bile acid-metabolising genes and their interaction with Angptl4 in intestinal mucosa of IBD patients. Show less