Epigenetic Age Research Articles

Epigenetic age and long-term cancer risk following a stroke

BackgroundThe association between increased cancer risk following a cerebrovascular event (CVE) has been previously reported. We hypothesize that biological age (B-age) acceleration is involved in this association. Our study aims to examine B-age as a novel contributing factor to cancer development post-CVE.MethodsFrom our prospective stroke registry (BasicMar), we selected 940 cases with epigenetic data. For this study, we specifically analyzed 648 of these patients who had available data, no prior history of cancer, and a minimum follow-up of 3 months. The primary outcome was cancer incidence. B-age was estimated using DNA methylation data derived from whole blood samples obtained within 24 h of stroke onset, employing various epigenetic clocks (including Hannum, Horvath, PhenoAge, ZhangBLUP, ZhangEN, and the mitotic epiTOC). Extrinsic epigenetic age acceleration (EEAA) was calculated as the residuals from the regression of B-age against chronological age (C-age). For epiTOC, the age-adjusted values were obtained by regressing out the effect of age from the raw epiTOC measurements. Estimated white cell counts were derived from DNA methylation data, and these cell fractions were used to compute the intrinsic epigenetic age acceleration (IEAA). Subsequently, we evaluated the independent association between EEAA, IEAA, and cancer incidence while controlling for potential confounding variables.ResultsAmong 648 patients with a median follow-up of 8.15 years, 83 (12.8%) developed cancer. Cox multivariable analyses indicated significant associations between Hannum, Zhang, and epiTOC EEAA and the risk of cancer after CVE. After adjusting for multiple testing and competing risks, EEAA measured by Hannum clock maintained an independent association with cancer risk. Specifically, for each year increase in Hannum’s EEAA, we observed a 6.0% increased incidence of cancer (HR 1.06 [1.02–1.10], p value = 0.002).ConclusionsOur findings suggest that epigenetic accelerated aging, as indicated by Hannum’s EEAA, may play a significant role in the increased cancer risk observed in CVE survivors.

Technical variability across the 450K, EPICv1, and EPICv2 DNA methylation arrays: lessons learned for clinical and longitudinal studies

DNA methylation (DNAm) is the most commonly measured epigenetic mechanism in human populations, with most studies using Illumina arrays to assess DNAm levels. In 2023, Illumina updated their DNAm arrays to the EPIC version 2 (EPICv2), building on prior iterations, namely the EPIC version 1 (EPICv1) and 450K arrays. Whether DNAm measurements are stable across these three generations of arrays has yet not been investigated, limiting the ability of researchers—especially those with longitudinal data—to compare and replicate results across arrays. Here, we present results from a study of 30 child participants (15 male; 15 female) from the Drakenstein Child Health Study, who had DNAm measured on all three of the latest arrays: 450K, EPICv1, and EPICv2. Using these data, we created an annotation of probe quality across arrays, which includes the intraclass correlations, interquartile ranges, correlations, and array bias (i.e., the extent to which DNAm levels were explained by array type) of all CpGs. We also present results from an analysis of sex differences, where we found that CpGs with lower replicability across arrays had higher array-based variance, suggesting this variance metric help guide replication efforts. We also showed that epigenetic age estimates across arrays were more stable when using the principal component versions of epigenetic clocks. Ultimately, this collection of results provides a framework for investigating the replicability and longitudinal stability of epigenetic changes across multiple versions of Illumina DNAm arrays.

War Exposure and DNA Methylation in Syrian Refugee Children and Adolescents

Exposure to war is associated with poor mental health outcomes. Adverse and traumatic experiences can lead to long-lasting DNA methylation changes, potentially mediating the link between adversity and mental health. To date, limited studies have investigated the impact of war on DNA methylation in children or adolescents, hampering our understanding of the biological impact of war exposure. To identify salivary DNA methylation differences associated with war exposure in refugee children and adolescents. This cohort study included Syrian refugee children and adolescents, and their primary caregiver were recruited from tented settlements in Lebanon. Data collection was carried out in 2 waves, 1 year apart, from October 2017 to January 2018 and October 2018 to January 2019. Children and their caregiver were interviewed, and children provided saliva samples for DNA extraction. Data analysis was conducted in 2022, 2023, and 2024. War exposure assessed by interviewing children and their caregiver using the War Events Questionnaire. Salivary DNA methylation levels were assayed with the Infinium MethylationEPIC BeadChip (Illumina). Epigenetic aging acceleration was estimated using a set of preexisting epigenetic aging clocks. A literature search was conducted to identify previously reported DNA methylation correlates of childhood trauma. The study population included 1507 children and adolescents (mean [SD] age, 11.3 [2.4] years; age range, 6-19 years; 793 female [52.6%]). A total of 1449 children provided saliva samples for DNA extraction in year 1, and 872 children provided samples in year 2. Children who reported war events had a number of differentially methylated sites and regions. Enrichment analyses indicated an enrichment of gene sets associated with transmembrane transport, neurotransmission, and intracellular movement in genes that exhibited differential methylation. Sex-stratified analyses found a number of sex-specific DNA methylation differences associated with war exposure. Only 2 of 258 (0.8%) previously reported trauma-associated DNA methylation sites were associated with war exposure (B = -0.004; 95% CI, -0.005 to -0.003; Bonferroni P = .04 and B = -0.005; 95% CI, -0.006 to -0.004; Bonferroni P = .03). Any war exposure or bombardment was nominally associated with decreased epigenetic age using the Horvath multitissue clock (B = -0.39; 95% CI, -0.63 to -0.14; P = .007 and B = -0.42; 95% CI, -0.73 to -0.11; P = .002). In this cohort of Syrian refugee children and adolescents, war exposure was associated with a small number of distinct differences in salivary DNA methylation.

Association between advanced fibrosis and epigenetic age acceleration among individuals with MASLD.

The biological process of aging plays an important role in the progress of liver fibrosis. However, epidemiological evidence about the associations between advanced fibrosis and epigenetic age acceleration (EAA) among individuals with metabolic dysfunction-associated steatotic liver disease (MASLD) is limited. We utilized publicly available DNA methylation data (GSE180474) for our analysis. Five EAA measures were calculated in this study, including IEAA, PhenoAA, GrimAA, DunedinPACE, and DNAmTLAA. Separate linear regression models were conducted to explore the associations between different fibrosis grades and each measure of EAA. A total of 325 participants were included in this study, with a mean (± SD) age of 48.56 ± 11.50years. Of these participants, 64.6% with no fibrosis, 16.9% with bridging fibrosis, 11.1% with incomplete cirrhosis, and 7.4% with cirrhosis. After adjusting for demographics and medication status, MASLD individuals with advanced fibrosis were associated with a 5% increase in the pace of aging (DunedinPACE, β = 0.05, 95% CI: 0.03-0.07) and a 10% decrease in DNAmTLAA (β = -0.10, 95% CI: -0.13 to -0.07) compared those without fibrosis. Similarly, higher stages of fibrosis were associated with an increased pace of aging (DunedinPACE, β = 0.02, 95% CI: 0.01-0.03, Ptrend < 0.001) and decreased DNAmTLAA (β = -0.05, 95% CI: -0.07 to -0.04, Ptrend < 0.001). However, no significant association was found between advanced fibrosis and IEAA, PhenoAA, and GrimAA. Our findings suggest that advanced fibrosis was associated with an accelerated pace of aging, as measured by the third-generation EA measure DunedinPACE, and shorter telomere length, captured by DNAmTLAA, among individuals with MASLD. This finding has potential prognostic implications and suggests EAA may serve as a surrogate marker of therapeutic efficacy in MASLD.

Associations of epigenetic age acceleration at birth and age 12 years with adolescent cardiometabolic risk: the HOME study

BackgroundCardiometabolic risk factors among youth are rising. Epigenetic age acceleration, a biomarker for aging and disease-risk, has been associated with adiposity in children, but its association with other cardiometabolic risk markers remains understudied. We employed data from the Health Outcomes and Measures of the Environment (HOME) study, a prospective pregnancy and birth cohort in the greater Cincinnati metropolitan area, to examine whether accelerated epigenetic age at birth as well as accelerated epigenetic age and faster pace of biological aging at age 12 years were associated with higher cardiometabolic risk in adolescents.ResultsAfter adjusting for potential confounders, including estimated cell type proportions, epigenetic gestational age acceleration at birth, derived from the Bohlin, Knight, and Haftorn clocks using cord blood DNA methylation data, was not associated with cardiometabolic risk z-scores or individual cardiometabolic risk score components (visceral fat, leptin to adiponectin ratio, HOMA-IR, triglycerides to HDL-C ratio, HbA1c, or systolic blood pressure) at age 12 years. We also did not observe any associations of epigenetic age acceleration, calculated with Horvath’s skin and blood, Hannum’s, and Wu’s epigenetic clocks using peripheral blood at age 12 years, with these same cardiometabolic risk markers. In contrast, faster pace of biological aging was associated with higher cardiometabolic risk [βs (95% CIs)] cardiometabolic risk score 0.25 (0.07, 0.42); visceral fat 0.21 (0.05, 0.38); and hemoglobin A1c 0.23 (0.05, 0.41) per standard deviation increase in pace of biological aging. Faster pace of biological aging was also positively associated with systolic blood pressure, triglycerides to HDL-C ratio, HOMA-IR, and leptin to adiponectin ratio, although these associations were not statistically significant.ConclusionsOur findings provide evidence that faster pace of biological aging was associated with higher cardiometabolic risk score, visceral fat, and HbA1c at age 12 years. Further research is needed to determine whether these associations persist from adolescence through adulthood.

The Multi-State Epigenetic Pacemaker enables the identification of combinations of factors that influence DNA methylation.

Epigenetic clocks, DNA methylation-based predictive models of chronological age, are often utilized to study aging associated biology. Despite their widespread use, these methods do not account for other factors that also contribute to the variability of DNA methylation data. For example, many CpG sites show strong sex-specific or cell-type-specific patterns that likely impact the predictions of epigenetic age. To overcome these limitations, we developed a multidimensional extension of the Epigenetic Pacemaker, the Multi-state Epigenetic Pacemaker (MSEPM). We show that the MSEPM is capable of accurately modeling multiple methylation-associated factors simultaneously, while also providing site-specific models that describe the per site relationship between methylation and these factors. We utilized the MSEPM with a large aggregate cohort of blood methylation data to construct models of the effects of age-, sex-, and cell-type heterogeneity on DNA methylation. We found that these models capture a large faction of the variability at thousands of DNA methylation sites. Moreover, this approach allows us to identify sites that are primarily affected by aging and no other factors. An analysis of these sites reveals that those that lose methylation over time are enriched for CTCF transcription factor chip peaks, while those that gain methylation over time are associated with bivalent promoters of genes that are not expressed in blood. These observations suggest mechanisms that underlie age-associated methylation changes and suggest that age-associated increases in methylation may not have strong functional consequences on cell states. In conclusion, the MSEPM is capable of accurately modeling multiple methylation-associated factors, and the models produced can illuminate site-specific combinations of factors that affect methylation dynamics.

Effect of nicotinamide riboside on airway inflammation in COPD: a randomized, placebo-controlled trial.

Chronic obstructive pulmonary disease (COPD) is a progressive, incurable disease associated with smoking and advanced age, ranking as the third leading cause of death worldwide. DNA damage and loss of the central metabolite nicotinamide adenine dinucleotide (NAD+) may contribute to both aging and COPD, presenting a potential avenue for interventions. In this randomized, double-blind, placebo-controlled clinical trial, we treated patients with stable COPD (n = 40) with the NAD+ precursor nicotinamide riboside (NR) for 6 weeks and followed-up 12 weeks later. The primary outcome was change in sputum interleukin-8 (IL-8) from baseline to week 6. The estimated treatment difference between NR and placebo in IL-8 after 6 weeks was -52.6% (95% confidence interval (CI): -75.7% to -7.6%; P = 0.030). This effect persisted until the follow-up 12 weeks after the end of treatment (-63.7%: 95% CI -85.7% to -7.8%; P = 0.034). For secondary outcomes, NR treatment increased NAD+ levels by more than twofold in whole blood, whereas IL-6 levels in plasma remained unchanged. In exploratory analyses, treatment with NR showed indications of upregulated gene pathways related to genomic integrity in the airways and reduced epigenetic aging, possibly through a reduction in cellular senescence. These exploratory analyses need to be confirmed in future trials. ClinicalTrials.gov identifier: NCT04990869 .

Meta-analyses of epigenetic age acceleration and GrimAge components of schizophrenia or first-episode psychosis

Schizophrenia is a common chronic psychiatric disorder that causes age-related dysfunction. The life expectancy in patients with schizophrenia is ≥10 years shorter than that in the general population because of the higher risk of other diseases, such as cardiovascular diseases. Aging studies based on DNA methylation status have received considerable attention. Several epigenetic age accelerations and predicted values of aging-related proteins (GrimAge and GrimAge2 components) have been analyzed in multiple diseases. However, no studies have investigated up to GrimAge and GrimAge2 components between patients with schizophrenia and controls. Therefore, we aimed to conduct multiple regression analyses to investigate the association between schizophrenia and epigenetic age accelerations and GrimAge and GrimAge2 components in seven cohorts. Furthermore, we included patients with first-episode psychosis whose illness duration was often shorter than schizophrenia in our analysis. We integrated these results with meta-analyses, noting the acceleration of GrimAge, GrimAge2, and DunedinPACE, and increase in adrenomedullin, beta-2 microglobulin, cystatin C, and plasminogen activation inhibitor-1 levels, in patients with schizophrenia or first-episode psychosis. These results corroborated the finding that patients with schizophrenia had an increased risk of diabetes, cardiovascular disease, and cognitive dysfunction from a biological perspective. Patients with schizophrenia and first-episode psychosis showed differences in the results when compared with controls. Such analyses may lead to the development of novel therapeutic targets to patients with schizophrenia or relevant diseases from the perspective of aging in the future.

Adolescent empathy and epigenetic aging in adulthood: Substance use as a mediator.

Prosocial behavior during adolescence has been associated with better physical health, including slower epigenetic aging. However, little is known about the specific role of empathy in epigenetic aging and the mechanisms explaining this relationship. One such mechanism may be substance use, which is predicted by low empathy and contributes to accelerated epigenetic aging. Thus, the present study examined whether empathy during early adolescence predicts epigenetic aging in young adulthood and whether substance use in late adolescence and young adulthood mediates this effect. Participants included 343 individuals (58% female, 81% Black, 19% White) who were interviewed at mean ages of 13, 17, and 27 years. Participants self-reported their empathy at Time 1 and their alcohol, tobacco, and cannabis use at Times 2 and 3. At Time 3, epigenetic aging was assessed from salivary DNA using the GrimAge, DunedinPACE, and PhenoAge clocks. A regression analysis demonstrated that higher empathy in early adolescence uniquely predicted lower epigenetic aging on the GrimAge clock in young adulthood even after adjusting for environmental and sociodemographic risk factors. Mediation models revealed that the link between empathy and lower epigenetic aging on all three clocks was mediated by lower tobacco use. These results suggest that higher empathy during early adolescence may contribute to better health throughout the lifespan due to lower tobacco use and slower epigenetic aging. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Resilience to psychosocial stress and epigenetic aging in schizophrenia: findings from a pilot study.

Exposure to stress is known to affect biological aging as well as individuals' susceptibility to a wide variety of mental illnesses, such as schizophrenia. There is an established relationship between the onset of schizophrenia spectrum disorders (SSD) and biological aging. On the other hand, epigenetic modifications, such as DNA methylation (DNAm), are used as biomarkers for biological aging and were previously proven to be altered in schizophrenia. However, previous research did not consider the effect of psychosocial resilience to stress and its effect on aging in schizophrenia, which is what our study aims to address. For our pilot study, 65 schizophrenia patients were recruited and stress exposure and perception levels were assessed using the Social Readjustment Rating Scale (SRRS) and Perceived Stress Scale (PSS), respectively. Moreover, DNA was extracted from venous blood samples and 850,000 CpG loci were assessed for DNA methylation analysis. Average age of participants was 43.15 ± 13.32 years (55.4% male, 44.6% female). Linear regression plots showed significant correlation between SRRS and PSS scores as well as between biological and chronological ages (p < 0.05). The residuals from the two regression models were defined as the psychosocial resilience and DNAm age acceleration, respectively. Interestingly, DNAm age acceleration was inversely correlated with resilience to stress (p < 0.05). In conclusion, it appears that epigenetic age acceleration is associated with reduced resilience to stress in schizophrenia patients. Future studies should focus on establishing resilience effect on disease prognosis.

Physical activity and DNA methylation-based markers of ageing in 6208 middle-aged and older Australians: cross-sectional and longitudinal analyses.

Epigenetic age quantifies biological age using DNA methylation information and is a potential pathway by which physical activity benefits general health. We aimed to assess the cross-sectional and longitudinal associations between physical activity and epigenetic age in middle-aged and older Australians. Blood DNA methylation data for 6208 participants (40% female) in the Melbourne Collaborative Cohort Study (MCCS) were available at baseline (1990-1994, mean age, 59years) and, of those, for 1009 at follow-up (2003-2007, mean age, 69years). Physical activity measurements (weighted scores at baseline and follow-up and total MET hours per week at follow-up) were calculated from self-reported questionnaire data. Five blood methylation-based markers of ageing (PCGrimAge, PCPhenoAge, bAge, DNAmFitAge, and DunedinPACE) and four fitness-related markers (DNAmGaitspeed, DNAmGripmax, DNAmVO2max, and DNAmFEV1) were calculated and adjusted for age. Linear regression was used to examine the cross-sectional and longitudinal associations between physical activity and epigenetic age. Effect modification by age, sex, and BMI was assessed. At baseline, a standard deviation (SD) increment in physical activity was associated with 0.03-SD (DNAmFitAge, 95%CI = 0.01, 0.06, P = 0.02) to 0.07-SD (bAge, 95%CI = 0.04, 0.09, P = 2 × 10-8) lower epigenetic age. These associations were attenuated after adjustment for other lifestyle variables. Only weak evidence was found for the longitudinal association (N = 1009) of changes in physical activity and epigenetic age (e.g. DNAmFitAge: adjusted β = - 0.04, 95%CI = - 0.08, 0.01). The associations were not modified by age, sex, or BMI. In middle-aged and older Australians, higher levels of self-reported physical activity were associated with slightly lower epigenetic age.

Aging drives a program of DNA methylation decay in plant organs.

How organisms age is a question with broad implications for human health. In mammals, DNA methylation is a biomarker for biological age, which may predict age more accurately than date of birth. However, limitations in mammalian models make it difficult to identify mechanisms underpinning age-related DNA methylation changes. Here, we show that the short-lived model plant Arabidopsis thaliana exhibits a loss of epigenetic integrity during aging, causing heterochromatin DNA methylation decay and the expression of transposable elements. We show that the rate of epigenetic aging can be manipulated by extending or curtailing lifespan, and that shoot apical meristems are protected from this aging process. We demonstrate that a program of transcriptional repression suppresses DNA methylation maintenance pathways during aging, and that mutants of this mechanism display a complete absence of epigenetic decay. This presents a new paradigm in which a gene regulatory program sets the rate of epigenomic information loss during aging.

BS-clock, advancing epigenetic age prediction with high-resolution DNA methylation bisulfite sequencing data.

DNA methylation patterns provide precise and accurate estimates of biological age due to their robustness and predictable changes associated with aging processes. Although several methylation aging clocks have been developed in recent years, they are primarily designed for DNA methylation array data, which has limited CpG coverage and detection sensitivity compared to bisulfite sequencing data. Here, we present BS-clock, a novel DNA methylation clock for human aging based on bisulfite sequencing data. Using BS-seq data from 529 samples retrieved from four tissues, our BS-clock achieves higher correlations with chronological age in multiple tissue types compared to existing array-based clocks. Our study revealed age-dependent aging rates across different age stages and disease conditions, and overall low cross-tissue prediction capability by applying the model trained on one tissue type to others. In summary, BS-clock overcomes limitations of array-based techniques, offering genome-wide CpG site coverage and more robust and accurate aging quantification. This research paves the way for advanced epigenetic studies of aging and holds promise for developing targeted interventions to promote healthy aging. All analysis codes for reproducing the results of the study are publicly available at https://github.com/hucongcong97/BS-clock. Supplementary data are available at Bioinformatics online.

Causal associations and shared genetic etiology of neurodegenerative diseases with epigenetic aging and human longevity.

The causative mechanisms underlying the genetic relationships of neurodegenerative diseases with epigenetic aging and human longevity remain obscure. We aimed to detect causal associations and shared genetic etiology of neurodegenerative diseases with epigenetic aging and human longevity. We obtained large-scale genome-wide association study summary statistics data for four measures of epigenetic age (GrimAge, PhenoAge, IEAA, and HannumAge) (N = 34,710), multivariate longevity (healthspan, lifespan, and exceptional longevity) (N = 1,349,462), and for multiple neurodegenerative diseases (N = 6618-482,730), including Lewy body dementia, Alzheimer's disease (AD), Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. Main analyses were conducted using multiplicative random effects inverse-variance weighted Mendelian randomization (MR), and conditional/conjunctional false discovery rate (cond/conjFDR) approach. Shared genomic loci were functionally characterized to gain biological understanding. Evidence showed that AD patients had 0.309 year less in exceptional longevity (IVW beta = -0.309, 95% CI: -0.38 to -0.24, p = 1.51E-19). We also observed suggestively significant causal evidence between AD and GrimAge age acceleration (IVW beta = -0.10, 95% CI: -0.188 to -0.013, p = 0.02). Following the discovery of polygenic overlap, we identified rs78143120 as shared genomic locus between AD and GrimAge age acceleration, and rs12691088 between AD and exceptional longevity. Among these loci, rs78143120 was novel for AD. In conclusion, we observed that only AD had causal effects on epigenetic aging and human longevity, while other neurodegenerative diseases did not. The genetic overlap between them, with mixed effect directions, suggested complex shared genetic etiology and molecular mechanisms.

Does High Self-Control Accelerate Epigenetic Aging in Low-Income Adolescents?

PurposePersistent self-control in the context of upward mobility in low-income adolescents, especially those of color, may have physiological costs, such as greater risks of developing cardiometabolic diseases in young adulthood. One potential mechanism linking self-control to cardiometabolic health is epigenetic age acceleration (EAA). However, little is known regarding the association between high self-control and EAA, as well as what factors may play protective roles. Therefore, we evaluated (1) the association between self-control and EAA and if this association varies by race and ethnicity, and (2) whether neighborhood collective efficacy (NCE) and school connectedness moderate the association in low-income adolescents. MethodsThis study used data from the Future of Families and Child Wellbeing Study. Participants included 772 adolescents with a household income <300% of poverty level (mean age: 15.6 years). Self-control, NCE, and school connectedness were all self-reported. EAA was assessed in saliva and estimated using Horvath, Skin and Blood, and Pediatric-Buccal-Epigenetic clocks. Multiple linear regression and PROCESS analyses were employed. ResultsHigher self-control was positively associated with EAA estimated by the skin and blood clock in low-income adolescents of color. Further, the association of higher self-control with EAA was not significant among low-income adolescents of color with higher NCE. No significant association was found among low-income White adolescents. DiscussionThe results suggest that supportive resources like neighborhood collective efficacy could mitigate adverse associations of high self-control with health in low-income adolescents of color.

ERJ advances: epigenetic ageing and leveraging DNA methylation in chronic respiratory diseases.

ERJ advances: epigenetic ageing and leveraging DNA methylation in chronic respiratory diseases.

Epistemic uncertainty challenges aging clock reliability in predicting rejuvenation effects.

Epigenetic aging clocks have been widely used to validate rejuvenation effects during cellular reprogramming. However, these predictions are unverifiable because the true biological age of reprogrammed cells remains unknown. We present an analytical framework to consider rejuvenation predictions from the uncertainty perspective. Our analysis reveals that the DNA methylation profiles across reprogramming are poorly represented in the aging data used to train clock models, thus introducing high epistemic uncertainty in age estimations. Moreover, predictions of different published clocks are inconsistent, with some even suggesting zero or negative rejuvenation. While not questioning the possibility of age reversal, we show that the high clock uncertainty challenges the reliability of rejuvenation effects observed during invitro reprogramming before pluripotency and throughout embryogenesis. Conversely, our method reveals a significant age increase after invivo reprogramming. We recommend including uncertainty estimation in future aging clock models to avoid the risk of misinterpreting the results of biological age prediction.

Epigenetic age acceleration is associated with occupational exposures, sex, and survival in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is linked to ageing and genetic and environmental risk factors, yet underlying mechanisms are incompletely understood. We aimed to evaluate epigenetic age acceleration (EAA), i.e., DNA methylation (DNAm) age acceleration, and its association with ALS case status and survival. In this study, we included 428 ALS and 288 control samples collected between 2011 and 2021. We calculated EAA using the GrimAge residual method from ALS and control blood samples and grouped participants with ALS into three ageing groups (fast, normal, slow). We associated EAA with ALS case status and survival, stratified by sex, and correlated it with environmental and biological factors through occupational exposure assessments, immune cell proportions, and transcriptome changes. Participants with ALS had higher average EAA by 1.80±0.30 years (p<0.0001) versus controls. Participants with ALS in the fast ageing group had a hazard ratio of 1.52 (95% confidence interval 1.16-2.00, p=0.0028) referenced to the normal ageing group. In males, this hazard ratio was 1.55 (95% confidence interval 1.11-2.17, p=0.010), and EAA was positively correlated with high-risk occupational exposures including particulate matter (adj.p<0.0001) and metals (adj.p=0.0087). Also, in male participants with ALS, EAA was positively correlated with neutrophil proportions and was negatively correlated with CD4+ T cell proportions. Pathways dysregulated in participants with ALS with fast ageing included spliceosome, nucleocytoplasmic transport, axon guidance, and interferons. EAA was associated with ALS case status and, at least in males, with shorter survival after diagnosis. The effect of EAA on ALS was partially explained by occupational exposures and immune cell proportions in a sex-dependent manner. These findings highlight the complex interactions of ageing and exposures in ALS. NIH, CDC/National ALS Registry, ALS Association, Dr. Randall Whitcomb Fund for ALS Genetics, Peter Clark Fund for ALS Research, Sinai Medical Staff Foundation, Scott L. Pranger ALS Clinic Fund, NeuroNetwork Therapeutic Discovery Fund, NeuroNetwork for Emerging Therapies.

The mitochondrial-targeted peptide therapeutic elamipretide improves cardiac and skeletal muscle function during aging without detectable changes in tissue epigenetic or transcriptomic age.

Aging-related decreases in cardiac and skeletal muscle function are strongly associated with various comorbidities. Elamipretide (ELAM), a novel mitochondrial-targeted peptide, has demonstrated broad therapeutic efficacy in ameliorating disease conditions associated with mitochondrial dysfunction across both clinical and pre-clinical models. ELAM is proposed to restore mitochondrial bioenergetic function by stabilizing inner membrane structure and increasing oxidative phosphorylation coupling and efficiency. Although ELAM treatment effectively attenuates physiological declines in multiple tissues in rodent aging models, it remains unclear whether these functional improvements correlate with favorable changes in molecular biomarkers of aging. Herein, we investigated the impact of 8-week ELAM treatment on pre- and post-measures of C57BL/6J mice frailty, skeletal muscle, and cardiac muscle function, coupled with post-treatment assessments of biological age and affected molecular pathways. We found that health status, as measured by frailty index, cardiac strain, diastolic function, and skeletal muscle force are significantly diminished with age, with skeletal muscle force changing in a sex-dependent manner. Conversely, ELAM mitigated frailty accumulation and was able to partially reverse these declines, as evidenced by treatment-induced increases in cardiac strain and muscle fatigue resistance. Despite these improvements, we did not detect statistically significant changes in gene expression or DNA methylation profiles indicative of molecular reorganization or reduced biological age in most ELAM-treated groups. However, pathway analyses revealed that ELAM treatment showed pro-longevity shifts in gene expression such as upregulation of genes involved in fatty acid metabolism, mitochondrial translation and oxidative phosphorylation, and downregulation of inflammation. Together, these results indicate that ELAM treatment is effective at mitigating signs of sarcopenia and heart failure in an aging mouse model, but that these functional improvements occur independently of detectable changes in epigenetic and transcriptomic age. Thus, some age-related changes in function may be uncoupled from changes in molecular biological age.

Multidimensional Epigenetic Clocks Demonstrate Accelerated Aging Across Physiological Systems in Schizophrenia: A Meta-Analysis.

Schizophrenia is associated with increased age-related morbidity, mortality, and frailty, which are not entirely explained by behavioral factors. Prior studies using epigenetic clocks have suggested that schizophrenia is associated with accelerated aging, however these studies have primarily used unidimensional clocks that summarize aging as a single "biological age" score. This meta-analysis uses multidimensional epigenetic clocks that split aging into multiple scores to analyze biological aging in schizophrenia. These novel clocks may provide more granular insights into the mechanistic relationships between schizophrenia, epigenetic aging, and premature morbidity and mortality. Selected studies included patients with schizophrenia-spectrum disorders and non- psychiatric controls with available DNA methylation data. Seven cross-sectional datasets were available for this study, with a total sample size of 1,891 patients with schizophrenia and 1,881 controls. Studies were selected by consensus Meta-analyses were performed using fixed-effect models. We analyzed multidimensional epigenetic clocks, including causality- enriched CausAge clocks, physiological system-specific SystemsAge clocks, RetroelementAge, DNAmEMRAge, and multi omics-informed OMICmAge. Meta-analyses examined clock associations with schizophrenia disease status and clozapine use, after accounting for age and sex. Overall SystemsAge, CausAge, DNAmEMRAge, and OMICmAge scores demonstrated increased epigenetic aging in patients with schizophrenia after strict multiple-comparison testing. Ten of the eleven SystemsAge sub-clocks corresponding to different physiological systems demonstrated increased aging, with strongest effects for Heart and Lung followed by Metabolic and Brain systems. The causality- enriched clocks indicated increases in both damaging and adaptive aging, though these effects were weaker compared to SystemsAge scores. OMICmAge indicated changes in multiple clinical biomarkers, including hematologic and hepatic markers that support system-specific aging, as well as novel proteins and metabolites not previously linked to schizophrenia. Most clocks demonstrated age acceleration at the first psychotic episode. Notably, clozapine use was associated with increased Heart and Inflammation aging, which may partially be driven by smoking. Most results survived strict Bonferroni multiple testing correction. These are the first analyses of novel multidimensional clocks in patients with schizophrenia and provide a nuanced view of aging that identifies multiple organ systems at high risk for disease in schizophrenia-related disorders.