Biology subjects

MacIsaac, J.

Publications and source records attributed to MacIsaac, J..

3 recordsLinked to original sources

bioRxiv2026

Elexacaftor/tezacaftor/ivacaftor treatment is associated with epigenetic age deceleration in cystic fibrosis

Background: Cystic fibrosis (CF) is associated with chronic inflammation and progressive multisystem disease, which may contribute to accelerated biological aging. Elexacaftor/tezacaftor/ivacaftor (ETI) substantially improves clinical outcomes in people with CF (pwCF), but its effects on epigenetic aging and their relationship with inflammation remain poorly understood. Methods: We performed a pilot longitudinal study of 8 modulator-naive pwCF. Blood DNA methylation was profiled before ETI initiation and after 1 year of treatment. DNAmGrimAge2 age acceleration was calculated adjusting for chronological age and blood cell composition. Associations with inflammatory biomarkers and clinical measures were assessed using repeated measures correlation. Results: DNAmGrimAge2 was strongly correlated with chronological age at baseline and follow-up. DNAmGrimAge2 age acceleration decreased after ETI treatment, from a median of 1.92 years before treatment to -1.70 years after 1 year (p=0.008). Greater age acceleration was associated with higher IL-6, IL-1{beta}, and calprotectin concentrations. Higher FEV1pp was associated with lower age acceleration, whereas higher sweat chloride was associated with greater age acceleration. Conclusions: DNAmGrimAge2 age acceleration decreased following ETI initiation and was associated with markers of innate and neutrophilic inflammation and CF disease activity. These findings suggest that epigenetic aging in CF may be dynamic and responsive to improvements in CFTR function and inflammatory disease burden. Larger longitudinal studies are needed to validate these findings and determine their relationship with long-term clinical outcomes.

genetics↗

bioRxiv2024

The CALERIE™ Genomic Data Resource

Caloric restriction (CR) slows biological aging and prolongs healthy lifespan in model organisms. Findings from CALERIE-2 - the first ever randomized, controlled trial of long-term CR in healthy, non-obese humans - broadly supports a similar pattern of effects in humans. To expand our understanding of the molecular pathways and biological processes underpinning CR effects in humans, we generated a series of genomic datasets from stored biospecimens collected from n=218 participants during the trial. These data constitute the first publicly-accessible genomic data resource for a randomized controlled trial of an intervention targeting the biology of aging. Datasets include whole-genome SNP genotypes, and three-timepoint-longitudinal DNA methylation, mRNA, and small RNA datasets generated from blood, skeletal muscle, and adipose tissue samples (total sample n=2327). The CALERIE Genomic Data Resource described in this article is available from the Aging Research Biobank. This multi-tissue, multi-omic, longitudinal data resource has great potential to advance translational geroscience.

genomics↗

bioRxiv2021

Alpha-synuclein induces epigenomic dysregulation of glutamate signaling and locomotor pathways

BackgroundMutations and multiplications in the gene encoding for alpha-synuclein are associated with Parkinsons disease (PD). However, not all individuals with alpha-synuclein variants develop PD, suggesting that additional factors are involved. We hypothesized that increased alpha-synuclein might alter epigenetic regulation of PD pathways. ObjectivesTo identify genome-wide DNA methylation and hydroxymethylation changes induced by overexpression of two alpha-synuclein variants in human dopaminergic neurons, and to relate these to the corresponding transcriptome. MethodsWe assessed DNA methylation and hydroxymethylation at >850,000 CpGs using the EPIC BeadChip in LUHMES cells differentiated to dopaminergic neurons. Control LUHMES neurons, LUHMES neurons overexpressing wild type alpha-synuclein, and LUHMES neurons overexpressing A30P alpha-synuclein were compared. We used SMITE network analysis to identify functionally related genes with altered DNA methylation, DNA hydroxymethylation, and/or gene expression, incorporating LUHMES H3K4me1 ChIP-seq to delineate enhancers in addition to the default promoter and gene body regions. ResultsUsing stringent statistical thresholds, we found that increased expression of wild type or A30P mutant alpha-synuclein induced DNA methylation changes at thousands of CpGs and DNA hydroxymethylation changes at hundreds of CpGs. Differentially methylated sites in both genotypes were enriched for several processes including movement-associated pathways and glutamate signaling. For glutamate and other signaling pathways (i.e. PDGF, insulin), this differential DNA methylation was also associated with transcriptional changes. ConclusionsOur results indicated that alpha-synuclein altered the DNA methylome of dopaminergic neurons, influencing regulation of pathways involved in development, signaling, and metabolism. This supports a role for alpha-synuclein in the epigenetic etiology of PD.

genomics↗