Biological age is increased by stress and restored upon recovery

Biomarkers of aging: from molecules and surrogates to physiology and function

Many countries face an unprecedented challenge in aging demographics. This has led to an exponential growth in research on aging, which, coupled to a massive financial influx of funding in the private and public sectors, has resulted in seminal insights into the underpinnings of this biological process. However, critical validation in humans has been hampered by the limited translatability of results obtained in model organisms, additionally confined by the need for extremely time-consuming clinical studies in the ostensible absence of robust biomarkers that would allow monitoring in shorter time frames. In the future, molecular parameters might hold great promise in this regard. In contrast, biomarkers centered on function, resilience, and frailty are available at the present time, with proven predictive value for morbidity and mortality. In this review, the current knowledge of molecular and physiological aspects of human aging, potential antiaging strategies, and the basis, evidence, and potential application of physiological biomarkers in human aging are discussed.

Epigenetic ageing clocks: statistical methods and emerging computational challenges

Over the past decade, epigenetic clocks have emerged as powerful machine learning tools, not only to estimate chronological and biological age but also to assess the efficacy of anti-ageing, cellular rejuvenation and disease-preventive interventions. However, many computational and statistical challenges remain that limit our understanding, interpretation and application of epigenetic clocks. Here, we review these computational challenges, focusing on interpretation, cell-type heterogeneity and emerging single-cell methods, aiming to provide guidelines for the rigorous construction of interpretable epigenetic clocks at cell-type and single-cell resolution.

Pregnancy-induced metabolic reprogramming and regenerative responses to pro-aging stresses

Pregnancy is associated with physiological adaptations that affect virtually all organs, enabling the mother to support the growing fetus and placenta while withstanding the demands of pregnancy. As a result, mammalian pregnancy is a unique state that exerts paradoxical effects on maternal health. On one hand, the metabolic stress induced by pregnancy can accelerate aging and functional decline in organs. On the other hand, pregnancy activates metabolic programming and tissue regenerative responses that can reverse age-related impairments. In this sense, the oocyte-to-blastocyst transition is not the only physiological reprogramming event in the mammalian body, as pregnancy-induced regeneration could constitute a second physiological reprogramming event. Here, we review findings on how pregnancy dualistically leads to aging and rejuvenation in the maternal body.

Associations of epigenetic aging and COVID- 19: A 3-year longitudinal study

Aging and COVID- 19 are known to influence DNA methylation, potentially affecting the rate of aging and the risk of disease. The physiological functions of 54 volunteers-including maximal oxygen uptake (VO₂ max), grip strength, and vertical jump-were assessed just before the COVID- 19 pandemic and again 3 years later. Of these volunteers, 27 had contracted COVID- 19. Eight epigenetic clocks were used to assess the rate of aging during the 3-year period: DNAmAge showed accelerated aging, and five clocks showed slowed aging (DNAmAgeSkinBlood, DNAmAgeHannum, DNAmFitAge, PhenoAge, and DNAmTL). When we considered only females, we observed a stronger effect in the increase of DNAmAge acceleration, while we observed slowed aging in the case of SkinBloodClock, and DNAmTL. The methylation of the promoter region of the H1 FNT genes, which encodes testis-specific histone H1 family member N (H1fnt) and plays a crucial role in spermatogenesis decreased the most significantly. In contrast, the promoter of CSTL1, which encodes Cystatin-like 1, showed the most significant increase. We found that having COVID- 19 during the 3-year study period significantly increased the progress of aging assessed by DNAmGrimAge, DNAmGrimAge2, and DNAmFitAge (p = 0.024, 0.047, 0.032, respectively, after we adjusted the analysis for baseline variables). The data suggest that COVID- 19 may have a mild long-term effect on epigenetic aging.

Linked emergence of racial disparities in mental health and epigenetic biological aging across childhood and adolescence

Marginalization due to structural racism may confer an increased risk for aging-related diseases - in part - via effects on people's mental health. Here we leverage a prospective birth cohort study to examine whether the emergence of racial disparities in mental health and DNA-methylation measures of biological aging (i.e., DunedinPACE, GrimAge Acceleration, PhenoAge Acceleration) are linked across childhood and adolescence. We further consider to what extent racial disparities are statistically accounted for by perinatal and postnatal factors in preregistered analyses of 4898 participants from the Future of Families & Child Wellbeing Study, of which 2039 had repeated saliva DNA methylation at ages 9 and 15 years. We find that racially marginalized children had higher levels of externalizing and internalizing behaviors and diverging longitudinal internalizing slopes. Black compared to White identifying children, children living in more racially segregated neighborhoods, and racially marginalized children more affected by colorism tended to have higher age-9 levels of biological aging and more biological age acceleration over adolescence. Notably, longitudinal increases in internalizing and externalizing behavior were correlated with increases in biological aging. While racial and ethnic disparities in mental health were largely statistically accounted for by socioeconomic variables, differences in biological aging were often still visible after including potential mediating variables. These findings underscore the urgency for future research to consider biological aging processes from early life and collect more comprehensive measures of structural racism in developmental cohorts. Programs dedicated to advancing racial health equity must address the psychological and physical effects of structural racism on children and adolescents.

Leveraging research into sex differences and steroid hormones to improve brain health

Sex differences, driven in part by steroid hormones, shape the structure and function of the brain throughout the lifespan and manifest across brain health and disease. The influence of steroid hormones on neuroplasticity, particularly in the adult hippocampus, differs between the sexes, which has important implications for disorders and diseases that compromise hippocampus integrity, such as depression and Alzheimer disease. This Review outlines the intricate relationship between steroid hormones and hippocampal neuroplasticity across the adult lifespan and explores how the unique physiology of male and female individuals can affect health and disease. Despite calls to include sex and gender in research, only 5% of neuroscience studies published in 2019 directly investigated the influence of sex. Drawing on insights from depression, Alzheimer disease and relevant hippocampal plasticity, this Review underscores the importance of considering sex and steroid hormones to achieve a comprehensive understanding of disease susceptibility and mechanisms. Such consideration will enable the discovery of personalized treatments, ultimately leading to improved health outcomes for all.

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.

The Relationship Between Biological Noise and Its Application: Understanding System Failures and Suggesting a Method to Enhance Functionality Based on the Constrained Disorder Principle

The Constrained Disorder Principle (CDP) offers a new framework for understanding how biological systems use and manage noise to maintain optimal functionality. This review explores the relationship between noise and biological systems at various scales, including genetic, cellular, and organ levels, and its implications for system malfunctions. According to the CDP, all systems require an optimal range of noise to function appropriately, and disease states can arise when these noise levels are disrupted. This review presents evidence supporting this principle across different biological contexts, such as genetic variability, cellular behavior, brain functions, human behavior, aging, evolution, and drug administration. For accurate clinical assessments, it is essential to distinguish between technical variability and intrinsic biological variability. When noise is adequately constrained, it serves as a fundamental mechanism for system adaptation and optimal functioning rather than simply a source of disruption. These findings have important implications for developing more effective therapeutic strategies and understanding biological systems' dynamics. CDP-based second-generation artificial intelligence systems can help regulate noise levels to address malfunctions. These systems have improved clinical outcomes in various conditions by incorporating controlled randomness. Understanding these patterns of variability has significant implications for diagnosis, treatment monitoring, and the development of more effective therapeutic strategies across various medical conditions.

Biological age prediction and NAFLD risk assessment: a machine learning model based on a multicenter population in Nanchang, Jiangxi, China

BACKGROUND

The objective was to develop a biological age prediction model (NC-BA) for the Chinese population to enrich the relevant studies in this population. And to investigate the association between accelerated age and NAFLD.

METHODS

On the basis of the physical examination data of people without noninfectious chronic diseases (PWNCDs) in Nanchang, Jiangxi, China, the biological age measurement method was developed via three feature selection methods (all-subset regression, LASSO regression (LR), and recursive feature elimination) and three machine learning algorithms (generalized linear model (GLM), support vector machine, and deep generalized linear model (deep GLM)). Model performance was evaluated by the coefficient of determination (R²) and mean absolute error (MAE). National Health and Nutrition Examination Survey (NHANES) data were used to verify the model's generalizability. The standardized age deviation (SAD) was calculated to explore the associations between age acceleration and the risk of morbidity and mortality from NAFLD.

RESULTS

The physical examination data of 26,356 PWNCDs were collected in Nanchang. Among the 26 biomarkers, 26 and 24 biomarkers were associated with chronological age in the male and female groups, respectively (P < 0.05). The model combining the LR and deep GLM algorithms provided the most accurate measurement of chronological age (r = 0.58, MAE = 5.33) and was named the Nanchang-biological age (NC-BA) model. The generalizability of the NC-BA model was verified in the NHANES dataset (r = 0.57, MAE = 7.12). There was a significant correlation between NC-BA and existing biological age indicators (Klemera-Doubal method biological age (KDM-BA), PhenoAge, and homeostatic dysregulation (HD), r = 0.42-0.66, P < 0.05). The physical examination data of 1,663 and 1,445 patients with NAFLD from the Nanchang population and NHANES, respectively, were obtained. The SAD values of NAFLD patients were significantly greater than those of PWNCDs (P < 0.001). The SAD values of NAFLD patients with younger chronological ages were greater (P < 0.001). Higher SAD values were associated with a greater risk of all-cause mortality (HR = 1.73, P = 0.005).

CONCLUSIONS

This study provides a new model for biological age measurement in the Chinese population. There is a clear link between NAFLD and age acceleration.

Elevated urinary phytoestrogens are associated with delayed biological aging: a cross-sectional analysis of NHANES data

Dietary phytoestrogens have been suggested to provide protection against numerous age-related diseases. However, their effects on biological aging remain unclear. In this study, we cross-sectionally investigated the relationship between urinary phytoestrogen levels and indicators of biological aging using data from 7,981 adults who participated in the National Health and Nutrition Examination Survey 1999-2010. Urinary concentrations of six phytoestrogens, including four isoflavones and two enterolignans, were measured using high-performance liquid chromatography (HPLC)-tandem mass spectrometry (MS) or HPLC-atmospheric pressure photoionization-tandem MS, and standardized using urinary creatinine. Three indicators of biological age (BA), namely the Klemera-Doubal method biological age (KDM-BA), phenotypic age (PA), and homeostatic dysregulation (HD), were derived from 12 clinical biomarkers, advanced-BAs were calculated to quantify the differences between individuals' BAs and chronological age, and individuals with all positive advanced-BAs were defined as accelerated-aging. Weighted linear regression analysis showed that after adjusting for demographic and lifestyle factors and history of chronic diseases, elevated urinary total phytoestrogen and enterolignans were significantly associated with less advanced-KDM, advanced-PA, and advanced-HD, whereas elevated urinary isoflavones was significantly associated with less advanced-KDM and advanced-PA but not with advanced-HD. Weighted logistic regression showed that higher urinary levels of total phytoestrogen (highest Q4 vs. lowest Q1: OR = 0.60, 95%CI: 0.44, 0.80; P-trend = 0.002) and enterolignans (Q4 vs. Q1: OR = 0.59, 95%CI: 0.45, 0.76; P-trend < 0.001) were significantly associated with lower odds of accelerated-aging, but this was not significant for isoflavones (Q4 vs. Q1: OR = 0.78, 95%CI: 0.60, 1.08; P-trend = 0.05). Subgroup analyses showed that negative associations were attenuated in non-overweight/obese participants and current cigarette smokers. In conclusion, higher levels of urinary phytoestrogens are related to markers of slower biological aging, suggesting an anti-aging effect of higher dietary phytoestrogen consumption, which warrants further investigations in longitudinal or interventional settings.

The Circulating Methylome in Childhood-Onset Inflammatory Bowel Disease

BACKGROUND

The genetic contribution to inflammatory bowel disease (IBD), encompassing both Crohn's disease (CD) and ulcerative colitis (UC), accounts for around 20% of disease variance, highlighting the need to characterize environmental and epigenetic influences. Recently, considerable progress has been made in characterizing the adult methylome in epigenome-wide association studies.

METHODS

We report detailed analysis of the circulating methylome in 86 patients with childhood-onset CD and UC and 30 controls using the Illumina Infinium Human MethylationEPIC platform.

RESULTS

We derived and validated a 4-probe methylation biomarker (RPS6KA2, VMP1, CFI, and ARHGEF3), with specificity and high diagnostic accuracy for pediatric IBD in UK and North American cohorts (area under the curve: 0.90-0.94). Significant epigenetic age acceleration is present at diagnosis, with the greatest observed in CD patients. Cis-methylation quantitative trait loci (meQTL) analysis identifies genetic determinants underlying epigenetic alterations notably within the HLA 6p22.1-p21.33 region. Passive smoking exposure is associated with the development of UC rather than CD, contrary to previous findings.

CONCLUSIONS

These data provide new insights into epigenetic alterations in IBD and illustrate the reproducibility and translational potential of epigenome-wide association studies in complex diseases.

Glucocorticoid exposure-induced alterations in epigenetic age from human preterm infants and human lung fibroblasts and hippocampal neuronal cells

BACKGROUND

Maternal antenatal corticosteroid treatment is standard care to accelerate fetal maturation. However, there are growing concerns that antenatal corticosteroid administration may harm fetal neurodevelopment. Quantitative assessments of the effects of antenatal corticosteroid on the neonates have not been performed and poorly understood about their complex biology.

RESULTS

We collected Methylation BeadChips-generated DNA methylation data from the Gene Expression Omnibus (GEO) database and then employed "multi-tissue predictor" to quantify the DNAm age of saliva from 36 preterm neonates, which were stratified by the absence (n = 12) or presence (n = 24) of antenatal corticosteroid exposure, as well as 36 full-term neonates. Next, the DNAm age of human lung fibroblast IMR90 cells and human fetal multipotent hippocampal progenitor HPC cells, with or without glucocorticoid treatment, was also determined. We observed that the DNAm age of full-term neonates was significantly higher than that of the preterm neonates, and antenatal corticosteroid exposure accelerated the DNAm age of preterm neonates, while glucocorticoid exposure accelerated the DNAm age of IMR90 cells. Conversely, dexamethasone exposure delayed the DNAm age of HPC cells during the proliferation phase. It is noteworthy that 65% of the differentially methylated probes (DMPs) linked to the multi-tissue predictor marked CpGs and corticosteroid exposure in IMR90 cells exhibited comparable methylation patterns with the DMPs associated with the antenatal corticosteroid exposure in preterm neonates. Conversely, the majority of these DMPs exhibited inverse methylation alterations in dexamethasone-induced HPC cells. Furthermore, the epigenome-wide association study (EWAS) trait enrichment analyses of the DMPs linked to the antenatal corticosteroid exposure in preterm neonates revealed significant associations with prenatal adverse environmental exposure, growth and development, and neuropsychiatric disorders.

CONCLUSIONS

Our results identified the cellular and molecular evidences of epigenetic clock changes in neonatal growth and developmental trajectories with the interference of antenatal corticosteroid treatment and provided potential clinical guidance for the future development of noninvasive fetal assessments to identify pregnant women who could benefit from antenatal corticosteroid in a wider gestational age.

Possible Anti-Aging and Anti-Stress Effects of Long-Term Transcendental Meditation Practice: Differences in Gene Expression, EEG Correlates of Cognitive Function, and Hair Steroids

Background: Our previous comparison of peripheral blood mononuclear cells (PBMCs) from long-term Transcendental Meditation® (TM®) practitioners and matched non-practitioner controls found 200 differentially expressed (DE) genes. Bioinformatics analyses of these DE genes suggested a reduced risk of diseases associated with stress and aging in the TM group. Here we assessed additional signs of reduced stress and aging. Methods: A sample of 15 of the 200 DE genes was studied using qPCR in PBMCs from 40-year TM practitioners ("Old TM", n = 23) compared to a "Young Control" group (n = 19) and an "Old Control" group (n = 21) of non-meditators. In these three groups, plus a "Young TM", 12-year practitioner group (n = 26), we also studied EEG-based parameters of cognitive function (the Brain Integration Scale (BIS), and latency of three components of the event-related potential (ERP)). Finally, using LC/MS/MS, we compared persistent levels of cortisol (F) and its inactive congener, cortisone (E), in hair. Results: qPCR analysis showed that 13 of the 15 genes were more highly expressed in Old Controls than in Young Controls. In the Old TM group, 7 of these 13 were lower than in Old Controls. Both TM groups had higher BIS scores than their age-matched controls. The Old TM group had shorter N2, P3a, and P3b latencies than the Old Control group, and latencies in the Old TM group were not longer than in the Young Control group. The Hair F/Hair E ratio was higher in the control subgroups than in their age-matched TM subgroups, and Hair F was higher in the Young Control and combined control groups than in the Young TM and combined TM groups. Conclusions: These results are consistent with reductions in biomarkers of chronic stress and biological age in long-term TM meditators. They are also consistent with results from the previous study suggesting that TM practice lowers energy consumption or leads to more efficient energy metabolism.

Biological aging of different blood cell types

Biological age (BA) captures detrimental age-related changes. The best-known and most-used BA indicators include DNA methylation-based epigenetic clocks and telomere length (TL). The most common biological sample material for epidemiological aging studies, whole blood, is composed of different cell types. We aimed to compare differences in BAs between blood cell types and assessed the BA indicators' cell type-specific associations with chronological age (CA). An analysis of DNA methylation-based BA indicators, including TL, methylation level at cg16867657 in ELOVL2, as well as the Hannum, Horvath, DNAmPhenoAge, and DunedinPACE epigenetic clocks, was performed on 428 biological samples of 12 blood cell types. BA values were different in the majority of the pairwise comparisons between cell types, as well as in comparison to whole blood (p < 0.05). DNAmPhenoAge showed the largest cell type differences, up to 44.5 years and DNA methylation-based TL showed the lowest differences. T cells generally had the "youngest" BA values, with differences across subsets, whereas monocytes had the "oldest" values. All BA indicators, except DunedinPACE, strongly correlated with CA within a cell type. Some differences such as DNAmPhenoAge-difference between naïve CD4 + T cells and monocytes were constant regardless of the blood donor's CA (range 20-80 years), while for DunedinPACE they were not. In conclusion, DNA methylation-based indicators of BA exhibit cell type-specific characteristics. Our results have implications for understanding the molecular mechanisms underlying epigenetic clocks and underscore the importance of considering cell composition when utilizing them as indicators for the success of aging interventions.

Smoke's Enduring Legacy: Bridging Early-Life Smoking Exposures and Later-Life Epigenetic Age Acceleration

Current literature states that early-life exposure to smoking produces adverse health outcomes in later life, primarily as a result of subsequent engagements with firsthand smoking. The implications of prior research are that smoking cessation can reduce health risk in later life to levels comparable to the risk of those who have never smoked. However, recent evidence suggests that smoking exposure during childhood can have independent and permanent negative effects on health-in particular, on epigenetic aging. This investigation examines whether the effect of early-life firsthand smoking on epigenetic aging is more consistent with (1) a sensitive periods model, which is characterized by independent effects due to early firsthand exposures; or (2) a cumulative risks model, which is typified by persistent smoking. The findings support both models. Smoking during childhood can have long-lasting effects on epigenetic aging, regardless of subsequent engagements. Our evidence suggests that adult cessation can be effective but that the epigenetic age acceleration in later life is largely due to early firsthand smoking itself.

Biological Age Affecting Attrition and Tooth Loss in a Follow-up Study

In population-based longitudinal studies, bias caused by nonresponse among eligible participants and attrition during follow-up thwarts conclusions. As this issue is not commonly addressed in dental studies, it is the aim of this study to examine the consequences of attrition with respect to tooth loss and mortality in a 10-y follow-up study. From the Study of Health in Pomerania (SHIP-0), a biological age (BA) score was constructed from 10 systemic biomarkers and related to one's actual chronological age (CA). The 3,417 dentate participants were stratified according to their BA-CA scores into tertiles: individuals with younger BA than their CA, those with concurrent BA and CA, and those with older BA than their CA. Baseline characteristics and propensity of leaving or remaining in the study were compared across these tertiles. We compared the characteristics within BA strata in the remainers of SHIP-2 (10-y follow-up) and their impact on tooth loss. Besides dropout by those who died, the attrition propensity of baseline study participants was dose dependent as related to BA-CA scores and socioeconomic factors. BA younger participants were underrepresented in dropouts but overrepresented in remaining follow-up participants. BA younger participants had a more favorable risk profile, better oral health, and a lower mortality rate than BA older participants. For the BA older participants, the opposite was observed. Remainers attaining the follow-up SHIP-2 were healthier and more health conscious. After 10 y, their tooth retention was still directed by BA constructed at baseline. The results support the assumption that individual risk profiles aggregated in BA constitute characteristic susceptibility patterns affecting perseverance or attrition in long-term follow-up studies. Attrition, which is common to follow-up studies, changes the study composition of participants depending on their BA and hence the transferability of results to the baseline population. The baseline BA gradient persists even after a long time.

EpiAge: a next-generation sequencing-based ELOVL2 epigenetic clock for biological age assessment in saliva and blood across health and disease

This study introduces EpiAgePublic, a new method to estimate biological age using only three specific sites on the gene ELOVL2, known for its connection to aging. Unlike traditional methods that require complex and extensive data, our model uses a simpler approach that is well-suited for next-generation sequencing technology, which is a more advanced method of analyzing DNA methylation. This new model overcomes some of the common challenges found in older methods, such as errors due to sample quality and processing variations. We tested EpiAgePublic with a large and varied group of over 4,600 people to ensure its accuracy. It performed on par with, and sometimes better than, more complicated models that use much more data for age estimation. We examined its effectiveness in understanding how factors like HIV infection and stress affect aging, confirming its usefulness in real-world clinical settings. Our results prove that our simple yet effective model, EpiAgePublic, can capture the subtle signs of aging with high accuracy. We also used this model in a study involving patients with Alzheimer's Disease, demonstrating the practical benefits of next-generation sequencing in making precise age-related assessments. This study lays the groundwork for future research on aging mechanisms and assessing how different interventions might impact the aging process using this clock.

Reproductive factors and biological aging: the association with all-cause and cause-specific premature mortality

STUDY QUESTION

Are reproductive factors associated with biological aging, and does biological aging mediate the associations of reproductive factors with premature mortality?

SUMMARY ANSWER

Multiple reproductive factors are related to phenotypic age acceleration (PhenoAge-Accel), while adherence to a healthy lifestyle mitigates these harmful effects; PhenoAge-Accel mediated the associations between reproductive factors and premature mortality.

WHAT IS KNOWN ALREADY

Accelerated aging is a key contributor to mortality, but knowledge about the effect of reproductive factors on aging is limited.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study included 223 729 women aged 40-69 years from the UK biobank in 2006-2010 and followed up until 12 November 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Reproductive factors were collected through a touchscreen questionnaire. Biological aging was assessed through PhenoAge-Accel. Multiple linear regression models were used to examine the relationships of reproductive factors with PhenoAge-Accel and estimate the modified effect of a healthy lifestyle. Furthermore, we applied mediation analysis to explore the mediating role of PhenoAge-Accel in the associations between reproductive factors and premature mortality.

MAIN RESULTS AND THE ROLE OF CHANCE

Early menarche (<12 years vs 13 years, β: 0.37, 95% CI: 0.30, 0.44), late menarche (≥15 years vs 13 years, β: 0.18, 95% CI: 0.11, 0.25), early menopause (<45 years vs 50-51 years, β: 0.62, 95% CI: 0.51, 0.72), short reproductive lifespan (<30 years vs 35-39 years, β: 0.81, 95% CI: 0.70, 0.92), nulliparity (vs two live births, β: 0.36, 95% CI: 0.30, 0.43), high parity (≥4 vs 2 live births, β: 0.49, 95% CI: 0.40, 0.59), early age at first live birth (<20 years vs 25-29 years, β: 0.66, 95% CI: 0.56, 0.75), and stillbirth (β: 0.51, 95% CI: 0.36, 0.65) were associated with increased PhenoAge-Accel. Furthermore, PhenoAge-Accel mediated 6.0%-29.7% of the associations between reproductive factors and premature mortality. Women with an unfavorable lifestyle and reproductive risk factors had the highest PhenoAge-Accel compared to those with a favorable lifestyle and without reproductive risk factors.

LIMITATIONS, REASONS FOR CAUTION

The participants in the UK Biobank were predominantly of White ethnicity; thus, caution is warranted when generalizing these findings to other ethnic groups.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings reveal the harmful effects of multiple reproductive factors on biological aging and the mediating role of biological aging in the associations between reproductive factors and premature mortality. They highlight the significance of adhering to a healthy lifestyle to slow biological aging as a potential way to reduce premature mortality among women with reproductive risk factors.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the National Natural Science Foundation of China (82003479, 82073660, 72204215), Hubei Provincial Natural Science Foundation of China (2023AFB663), Zhejiang Province Public Welfare Technology Application Research Project (GF22H269155), and China Postdoctoral Science Foundation (2019M662646, 2020T130220). The authors have no competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Remodeling of tumor microenvironment by cellular senescence and immunosenescence in cervical cancer

Cellular senescence is a response to various stress signals, which is characterized by stable cell cycle arrest, alterations in cellular morphology, metabolic reprogramming and production of senescence-associated secretory phenotype (SASP). When it occurs in the immune system, it is called immunosenescence. Cervical cancer is a common gynecological malignancy, and cervical cancer screening is generally recommended before the age of 65. Elderly women (≥65 years) are more often diagnosed with advanced disease and have poorer prognosis compared to younger patients. Despite extensive research, the tumor microenvironment requires more in-depth exploration, particularly in elderly patients. In cervical cancer, senescent cells have a double-edged sword effect on tumor progression. Induction of preneoplastic cell senescence prevents tumor initiation, and several treatment approaches of cervical cancer act in part by inducing cancer cell senescence. However, senescent immune cell populations within the tumor microenvironment facilitate tumor development, recurrence, treatment resistance, etc. Amplification of beneficial effects and inhibition of aging-related pro-tumorigenic pathways contribute to improving antitumor effects. This review discusses senescent cancer and immune cells present in the tumor microenvironment of cervical cancer and how these senescent cells and their SASP remodel the tumor microenvironment, influence antitumor immunity and tumor initiation and development. Moreover, we discuss the significance of senotherapeutics that enable to eliminate senescent cells and prevent tumor progression and development through improving antitumor immunity and affecting the tumor microenvironment.

Epigenetic Clocks: Beyond Biological Age, Using the Past to Predict the Present and Future

Predicting health trajectories and accurately measuring aging processes across the human lifespan remain profound scientific challenges. Assessing the effectiveness and impact of interventions targeting aging is even more elusive, largely due to the intricate, multidimensional nature of aging-a process that defies simple quantification. Traditional biomarkers offer only partial perspectives, capturing limited aspects of the aging landscape. Yet, over the past decade, groundbreaking advancements have emerged. Epigenetic clocks, derived from DNA methylation patterns, have established themselves as powerful aging biomarkers, capable of estimating biological age and assessing aging rates across diverse tissues with remarkable precision. These clocks provide predictive insights into mortality and age-related disease risks, effectively distinguishing biological age from chronological age and illuminating enduring questions in gerontology. Despite significant progress in epigenetic clock development, substantial challenges remain, underscoring the need for continued investigation to fully unlock their potential in the science of aging.

Salivary DNA methylation derived estimates of biological aging, cellular frequency and protein expression as predictors of oral mucositis severity and survival in head and neck cancer patients

BACKGROUND

Oral mucositis is a painful and debilitating condition that occurs in the majority of head and neck cancer patients receiving radiation and/or chemotherapy. While some patient and treatment related factors are known to contribute to the incidence and severity of disease, reliable biomarkers remain elusive. In the following study, we investigated the association of salivary DNA methylation derived biological aging, cellular frequency and protein concentration measures with the severity of oral mucositis and overall survival in a cohort of head and neck cancer (HNC) patients (n = 103).

METHODS

DNA methylation profiling was performed on saliva samples obtained prior to treatment. Biological aging measures included Horvath2, PhenoAge, FitAge and GrimAge, and cellular frequency included epithelial and specific immune cell populations.

RESULTS

Severe mucositis (i.e. grade 3 or 4) occurred in nearly half of patients. For malignant HNC patients (n = 84), every 1-SD increase in GrimAge was associated with 2.62-times risk of severe mucositis (95 % CI: 1.38, 5.57), while a 1-SD increase in monocyte frequency was associated with a decreased risk (OR [95 %CI]: 0.40 [0.18, 0.80]). Over a median follow-up of 53 months, 39 of 103 participants died. Six protein scores (TNFSF14, GCSF, MATN3, GDF8, nCDase, TNF-β) were associated with survival at q < 0.15.

CONCLUSION

We provide evidence that the risk-related biological aging measure GrimAge may be a useful predictor of mucositis severity in HNC patients. Salivary monocyte frequency may be protective against mucositis, and this measure could be used as a predictive biomarker while also providing clues into the pathobiology of the disease.

The impact of aging on HIV-1-related neurocognitive impairment

Depending on the population studied, HIV-1-related neurocognitive impairment is estimated to impact up to half the population of people living with HIV (PLWH) despite the availability of combination antiretroviral therapy (cART). Various factors contribute to this neurocognitive impairment, which complicates our understanding of the molecular mechanisms involved. Biological aging has been implicated as one factor possibly impacting the development and progression of HIV-1-related neurocognitive impairment. This is increasingly important as the life expectancy of PLWH with virologic suppression on cART is currently projected to be similar to that of individuals not living with HIV. Based on our increasing understanding of the biological aging process on a cellular level, we aim to dissect possible interactions of aging- and HIV-1 infection-induced effects and their role in neurocognitive decline. Thus, we begin by providing a brief overview of the clinical aspects of HIV-1-related neurocognitive impairment and review the accumulating evidence implicating aging in its development (Part I). We then discuss potential interactions between aging-associated pathways and HIV-1-induced effects at the molecular level (Part II).

Ectoin attenuates cortisone-induced skin issues by suppression GR signaling and the UVB-induced overexpression of 11β-HSD1

BACKGROUND

Accelerated pace of modern work and lifestyles subject individuals to various external and psychological stressors, which, in turn, can trigger additional stress through visible signs of fatigue, hair loss, and obesity. As the primary stress hormone affecting skin health, cortisol connects to the glucocorticoid receptor (GR) to aggravate skin issues induced by stress. This activation depends on the expression of 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) in skin cells, which locally converts cortisone-produced by the central and peripheral hypothalamic-pituitary-adrenal axis-into its active form.

METHODS

Our study delves deeper into stress's adverse effects on the skin, including the disruption of keratinocyte structural proteins, the loss of basement membrane proteins, and the degradation of collagen.

RESULTS

Remarkably, we discovered that Ectoin, an amino acid derivative obtained from halophilic bacteria, is capable of mitigating the inhibitory impacts of cortisone on the expression of cutaneous functional proteins, including involucrin, loricrin, laminin-5, and claudin-1. Moreover, Ectoin reduces the suppressive effect of stress on collagen and hyaluronic acid synthesis by impeding GR signal transduction. Additionally, Ectoin counterbalances the UVB-induced overexpression of 11β-HSD1, thereby diminishing the concentration of endogenous glucocorticoids.

CONCLUSION

Our findings illuminate the significant potential of Ectoin as a preventative agent against stress-induced skin maladies.

Reflections on resilience

Resilience research has long sought to understand how factors at the child, family, school, community, and societal levels shape adaptation in the face of adversities such as poverty and war. In this article we reflect on three themes that may prove to be useful for future resilience research. First is the idea that mental and physical health can sometimes diverge, even in response to the same social process. A better understanding of explanations for this divergence will have both theoretical and public health implications when it comes to efforts to promote resilience. Second is that more recent models of stress suggest that stress can accelerate aging. Thus, we suggest that research on resilience may need to also consider how resilience strategies may need to be developed in an accelerated fashion to be effective. Third, we suggest that if psychological resilience interventions can be conducted in conjunction with efforts to enact system-level changes targeted at adversities, this may synergize the impact that any single intervention can have, creating a more coordinated and effective set of approaches for promoting resilience in young people who confront adversity in life.

Persistent elevation of plasma markers of cellular senescence after hip fracture: a pilot longitudinal study

Introduction

Hip fractures may result from and contribute to accelerated biological aging. We aimed to evaluate the impact of hip fracture and its surgery on the senescence-associated secretory phenotype (SASP) index, a composite of peripheral protein markers where higher scores are thought to indicate greater levels of cellular senescence and accelerated aging.

Methods

We examined the SASP index in plasma over 12 weeks post-surgery and its prediction of long-term post-surgical functional outcomes. We included 60 older adults: 20 recruited immediately after hip fracture surgery, and 40 comparison individuals who were either healthy or suffering chronic psychosocial stress (caregiving). We assessed 22 SASP biomarkers and calculated the SASP index score for each hip fracture participant immediately following fracture surgery and 4 and 12 weeks later. Functional recovery was assessed at 12, 26, and 52 weeks after hip replacement surgery.

Results

The hip fracture group had higher SASP index scores than the comparison groups, after adjusting for potential confounding variables (p = 0.021). SASP index scores in hip fracture patients increased further by week 4 after surgery (p < 0.001), declining by week 12 but remaining elevated overall. However, the SASP index scores were not significantly associated with functional recovery after hip replacement surgery at 26 or 52 weeks after surgery. In conclusion, after hip fracture surgery SASP scores are elevated, continue to rise over time, and do not return to normal by 12 weeks post-surgery.

Discussion

Our findings support the need to investigate this phenomenon of post-operative senescence, including whether novel interventions such as senolytics would help older adults facing major surgery.

Precision Cut Lung Slices: Emerging Tools for Preclinical and Translational Lung Research. An Official American Thoracic Society Workshop Report

The urgent need for effective treatments for acute and chronic lung diseases underscores the significance of developing innovative preclinical human research tools. The 2023 ATS Workshop on Precision Cut Lung Slices (PCLS) brought together 35 experts to discuss and address the role of human tissue-derived PCLS as a unique tool for target and drug discovery and validation in pulmonary medicine. With increasing interest and usage, along with advancements in methods and technology, there is a growing need for consensus on PCLS methodology and readouts. The current document recommends standard reporting criteria and emphasizes the requirement for careful collection and integration of clinical metadata. We further discuss current clinically relevant readouts that can be applied to PCLS and highlight recent developments and future steps for implementing novel technologies for PCLS modeling and analysis. The collection and correlation of clinical metadata and multiomic analysis will further advent the integration of this preclinical platform into patient endotyping and the development of tailored therapies for lung disease patients.

The recovery of decreased executive attention in Tibetan migrants at high-altitude

Attention is one of the basic cognitive functions sensitive to high altitude, and most studies have focussed on exposure times of approximately 3 years; however, it is unclear how attention changes in migrants who have lived and worked at high altitude for nearly 20 years. We explored the dynamics of attentional networks and neurophysiological mechanisms in migrants over 3-20 years using the Attentional Network Test combined with Electrocardiograph and Electroencephalography and found a consistent quadratic correlation between exposure and executive control efficiency, P3 amplitude and heart rate variability (HRV), with a decrease followed by an increase/relative stability, with approximately 10 years being the breakpoint. However, neither linear nor quadratic trajectories were observed for the alerting and orienting network. Mediation analysis revealed that the P3 amplitude mediated the decrease and increase in executive control efficiency with exposure time depends on the breakpoint. Correlations between HRV and executive control efficiency and P3 amplitude suggest that U-shaped changes in executive control in migrants may be related to body homeostasis maintained by the autonomic nervous system, and that P3 amplitude may serve as a neurophysiological marker of migrants' adaptation/recovery from high-altitude exposure.

Exploring the potential of epigenetic clocks in aging research

The process of aging is a notable risk factor for numerous age-related illnesses. Hence, a reliable technique for evaluating biological age or the pace of aging is crucial for understanding the aging process and its influence on the progression of disease. Epigenetic alterations are recognized as a prominent biomarker of aging, and epigenetic clocks formulated on this basis have been shown to provide precise estimations of chronological age. Extensive research has validated the effectiveness of epigenetic clocks in determining aging rates, identifying risk factors for aging, evaluating the impact of anti-aging interventions, and predicting the emergence of age-related diseases. This review provides a detailed overview of the theoretical principles underlying the development of epigenetic clocks and their utility in aging research. Furthermore, it explores the existing obstacles and possibilities linked to epigenetic clocks and proposes potential avenues for future studies in this field.

Immune gene regulation is associated with age and environmental adversity in a nonhuman primate

Phenotypic aging is ubiquitous across mammalian species, suggesting shared underlying mechanisms of aging. Aging is linked to molecular changes to DNA methylation and gene expression, and environmental factors, such as severe external challenges or adversities, can moderate these age-related changes. Yet, it remains unclear whether environmental adversities affect gene regulation via the same molecular pathways as chronological, or 'primary', aging. Investigating molecular aging in naturalistic animal populations can fill this gap by providing insight into shared molecular mechanisms of aging and the effects of a greater diversity of environmental adversities - particularly those that can be challenging to study in humans or laboratory organisms. Here, we characterised molecular aging - specifically, CpG methylation - in a sample of free-ranging rhesus macaques living off the coast of Puerto Rico (n samples = 571, n individuals = 499), which endured a major hurricane during our study. Age was associated with methylation at 78,661 sites (31% of all sites tested). Age-associated hypermethylation occurred more frequently in areas of active gene regulation, while hypomethylation was enriched in regions that show less activity in immune cells, suggesting these regions may become de-repressed in older individuals. Age-associated hypomethylation also co-occurred with increased chromatin accessibility while hypermethylation showed the opposite trend, hinting at a coordinated, multi-level loss of epigenetic stability during aging. We detected 32,048 CpG sites significantly associated with exposure to a hurricane, and these sites overlapped age-associated sites, most strongly in regulatory regions and most weakly in quiescent regions. Together, our results suggest that environmental adversity may contribute to aging-related molecular phenotypes in regions of active gene transcription, but that primary aging has specific signatures in non-regulatory regions.

Profiling the transcriptomic age of single-cells in humans

Although aging clocks predicting the age of individual organisms have been extensively studied, the age of individual cells remained largely unexplored. Most recently single-cell omics clocks were developed for the mouse, however, extensive profiling the age of human cells is still lacking. To fill this gap, here we use available scRNA-seq data of 1,058,909 blood cells of 508 healthy, human donors (between 19 and 75 years), for developing single-cell transcriptomic clocks and predicting the age of human blood cells. By the application of the proposed cell-type-specific single-cell clocks, our main observations are that (i) transcriptomic age is associated with cellular senescence; (ii) the transcriptomic age of classical monocytes as well as naive B and T cells is decreased in moderate COVID-19 followed by an increase for some cell types in severe COVID-19; and (iii) the human embryo cells transcriptomically rejuvenated at the morulae and blastocyst stages. In summary, here we demonstrate that single-cell transcriptomic clocks are useful tools to investigate aging and rejuvenation at the single-cell level.

When to Trust Epigenetic Clocks: Avoiding False Positives in Aging Interventions

Recent human studies have suggested that aging interventions can reduce aging biomarkers related to morbidity and mortality risk. Such biomarkers may potentially serve as early, rapid indicators of effects on healthspan. An increasing number of studies are measuring intervention effects on epigenetic clocks, commonly used aging biomarkers based on DNA methylation profiles. However, with dozens of clocks to choose from, different clocks may not agree on the effect of an intervention. Furthermore, changes in some clocks may simply be the result of technical noise causing a false positive result. To address these issues, we measured the variability between 6 popular epigenetic clocks across a range of longitudinal datasets containing either an aging intervention or an age-accelerating event. We further compared them to the same clocks re-trained to have high test-retest reliability. We find the newer generation of clocks, trained on mortality or rate-of-aging, capture aging events more reliably than those clocks trained on chronological age, as these show consistent effects (or lack thereof) across multiple clocks including high-reliability versions, and including after multiple testing correction. In contrast, clocks trained on chronological age frequently show sporadic changes that are not replicable when using high-reliability versions of those same clocks, or when using newer generations of clocks and these results do not survive multiple-testing correction. These are likely false positive results, and we note that some of these clock changes were previously published, suggesting the literature should be re-examined. This work lays the foundation for future clinical trials that aim to measure aging interventions with epigenetic clocks, by establishing when to attribute a given change in biological age to a bona fide change in the aging process.

Psychosocial and neurobiological aspects of the worldwide refugee crisis: From vulnerability to resilience

Anisman, H., Doubad, D., Asokumar, A. & Matheson, K. Psychosocial and neurobiological aspects of the worldwide refugee crisis: From vulnerability to resilience. NEUROSCI BIOBEHAV REV, XXXX. Immigration occurs between countries either to obtain employment, for family reunification or to escape violence and other life-threatening conditions. Refugees and asylum seekers are often obligated to overcome a uniquely challenging set of circumstances prior to and during migration. Settlement following immigration may pose yet another set of stressors related to acculturation to the host country, as well as financial insecurity, discrimination, language barriers, and social isolation. Here we discuss the multiple consequences of immigration experiences, focusing on the health disturbances that frequently develop in adults and children. Aside from the psychosocial influences, immigration-related challenges may cause hormonal, inflammatory immune, and microbiota changes that favor psychological and physical illnesses. Some biological alterations are subject to modification by epigenetic changes, which have implications for intergenerational trauma transmission, as might disruptions in parenting behaviors and family dysfunction. Despite the hardships experienced, many immigrants and their families exhibit positive psychological adjustment after resettlement. We provide information to diminish the impacts associated with immigration and offer strength-based approaches that may foster resilience.

The brain-body energy conservation model of aging

Aging involves seemingly paradoxical changes in energy metabolism. Molecular damage accumulation increases cellular energy expenditure, yet whole-body energy expenditure remains stable or decreases with age. We resolve this apparent contradiction by positioning the brain as the mediator and broker in the organismal energy economy. As somatic tissues accumulate damage over time, costly intracellular stress responses are activated, causing aging or senescent cells to secrete cytokines that convey increased cellular energy demand (hypermetabolism) to the brain. To conserve energy in the face of a shrinking energy budget, the brain deploys energy conservation responses, which suppress low-priority processes, producing fatigue, physical inactivity, blunted sensory capacities, immune alterations and endocrine 'deficits'. We term this cascade the brain-body energy conservation (BEC) model of aging. The BEC outlines (1) the energetic cost of cellular aging, (2) how brain perception of senescence-associated hypermetabolism may drive the phenotypic manifestations of aging and (3) energetic principles underlying the modifiability of aging trajectories by stressors and geroscience interventions.

Challenges and recommendations for the translation of biomarkers of aging

Biomarkers of aging (BOA) are quantitative parameters that predict biological age and ideally its changes in response to interventions. In recent years, many promising molecular and omic BOA have emerged with an enormous potential for translational geroscience and improving healthspan. However, clinical translation remains limited, in part due to the gap between preclinical research and the application of BOA in clinical research and other translational settings. We surveyed experts in these areas to better understand current challenges for the translation of aging biomarkers. We identified six key barriers to clinical translation and developed guidance for the field to overcome them. Core recommendations include linking BOA to clinically actionable insights, improving affordability and availability to broad populations and validation of biomarkers that are robust and responsive at the level of individuals. Our work provides key insights and practical recommendations to overcome barriers impeding clinical translation of BOA.

Meta-Research in Geriatric Surgery: Improving the Quality of Surgical Evidence for Older Persons in a Multidimensional-Scale Research Field

The world is facing a significant demographic transition, with a substantial increase in the proportion of older persons, as well as long-lived persons (especially nonagenarians and centenarians). One of the popular beliefs is that old age is synonymous with disease and disability. However, the successful aging hypothesis suggests that those older persons with advanced chronological age who maintain their functional capacity derive from it a delay in biological aging, enhancing the quality of organic aging and regulation. Therefore, regardless of chronological age, even in cases of extreme longevity, those older adults with a successful aging phenotype and favorable functional capacity would be expected to have satisfactory post-surgical recovery with a low risk of morbidity and mortality. Currently, there is a significant gap between the availability of high-certainty surgical evidence that allows for evidence-based interventions applicable to the long-lived population-taking into account the actual conditioning factors of the health phenotype in older persons-and, above all, predictors of satisfactory post-surgical evolution. The application of meta-research to geriatric surgery emerges as a fundamental tool to address this knowledge gap and reveals opportunities and limitations that need to be resolved in the near future to establish evidence-based surgical care for older persons. The aim of this manuscript was to present a real and globally relevant scenario related to surgical care, addressing the longevity, the availability, and the quality of surgical evidence applicable to this population, and also to present variables to consider in analysis and future perspectives in research and meta-research in geriatric surgery.

Dissecting the impact of differentiation stage, replicative history, and cell type composition on epigenetic clocks

Epigenetic clocks, built on DNA methylation patterns of bulk tissues, are powerful age predictors, but their biological basis remains incompletely understood. Here, we conducted a comparative analysis of epigenetic age in murine muscle, epithelial, and blood cell types across lifespan. Strikingly, our results show that cellular subpopulations within these tissues, including adult stem and progenitor cells as well as their differentiated progeny, exhibit different epigenetic ages. Accordingly, we experimentally demonstrate that clocks can be skewed by age-associated changes in tissue composition. Mechanistically, we provide evidence that the observed variation in epigenetic age among adult stem cells correlates with their proliferative state, and, fittingly, forced proliferation of stem cells leads to increases in epigenetic age. Collectively, our analyses elucidate the impact of cell type composition, differentiation state, and replicative potential on epigenetic age, which has implications for the interpretation of existing clocks and should inform the development of more sensitive clocks.

Well-Being Outcomes of Health Care Workers After a 5-Hour Continuing Education Intervention: The WELL-B Randomized Clinical Trial

Importance

Compromised well-being in health care workers (HCWs) is detrimental to the workforce, organizations, and patients.

Objective

To test the effectiveness of Well-Being Essentials for Learning Life-Balance (WELL-B), a web-based continuing education program to deliver brief, evidence-based, reflective, psychological interventions to improve 4 dimensions of HCW well-being (ie, emotional exhaustion, emotional thriving, emotional recovery, and work-life integration).

Design, Setting, and Participants

A randomized clinical trial (RCT) of US inpatient and outpatient HCWs randomized 1:1 was conducted from January 3 through May 31, 2023, using a web-based intervention. Cohort 1 received 5 hours of WELL-B over 8 days; cohort 2 acted as the control group and received WELL-B after the end of the RCT. Eligibility criteria were US HCWs aged 18 years or older, including clinical (physician, nurse, and respiratory therapist) and nonclinical (administrative, information technology, and finance) roles.

Interventions

Continuing education sessions exposed participants to positive psychology interventions (gratitude letter, work-life integration, self-compassion and cultivating awe).

Main Outcomes and Measures

The primary outcome was emotional exhaustion on day 8; secondary outcomes included emotional thriving, emotional recovery, and work-life integration. All outcomes were measured using psychometrically valid scales previously reported in well-being RCTs and were assessed on days 1 and 8 (primary end point). Differences in outcome measures between the WELL-B intervention group and controls were assessed using t tests. Baseline-adjusted multiple linear regression models were evaluated to examine the association between the WELL-B intervention and the outcome measures after adjusting for additional covariates (sex, race and ethnicity, age, HCW role, and discipline). Intention-to-treat analysis was performed.

Results

The cohorts were similar at baseline, mostly female (528 [89%]) and nurses (177 [30%]). A total of 643 respondents participated in the study. In cohort 1, 331 participants initiated WELL-B, and 262 (71%) completed the day 8 follow-up; in cohort 2, 312 participants initiated WELL-B and 291 (77%) completed the day 8 follow-up. Compared with the control cohort, WELL-B significantly improved emotional exhaustion (estimate: -9.0; 95% CI, -13.1 to -4.9; P < .001), emotional thriving (estimate: 6.6; 95% CI, 3.2-10.0; P < .001), emotional recovery (estimate: 5.5; 95% CI, 2.0-9.0; P = .002), and work-life integration (estimate: -5.0; 95% CI, -8.2 to -1.9; P = .002). After adjusting for baseline outcome measures, sex, race and ethnicity, age, HCW role, and discipline, the linear regression model showed WELL-B improved day 8 emotional exhaustion (estimate: -9.6; 95% CI, -12.5 to -6.6; P < .001) compared with the control group. Favorable impressions of WELL-B were reported by more than 90% of the participants.

Conclusions and Relevance

In this RCT, brief well-being activities delivered during continuing education sessions improved short-term HCW emotional exhaustion, emotional thriving, emotional recovery, and work-life integration, with and without adjusting for covariates. Health care worker impressions of WELL-B were positive. These findings suggest that WELL-B is a beneficial intervention.

Trial Registration

ClinicalTrials.gov Identifier: NCT05636072.

Aging insights from heterochronic parabiosis models

Heterochronic parabiosis consists of surgically connecting the circulatory systems of a young and an old animal. This technique serves as a model to study circulating factors that accelerate aging in young organisms exposed to old blood or induce rejuvenation in old organisms exposed to young blood. Despite the promising results, the exact cellular and molecular mechanisms remain unclear, so this study aims to explore and elucidate them in more detail.

The activity of early-life gene regulatory elements is hijacked in aging through pervasive AP-1-linked chromatin opening

A mechanistic connection between aging and development is largely unexplored. Through profiling age-related chromatin and transcriptional changes across 22 murine cell types, analyzed alongside previous mouse and human organismal maturation datasets, we uncovered a transcription factor binding site (TFBS) signature common to both processes. Early-life candidate cis-regulatory elements (cCREs), progressively losing accessibility during maturation and aging, are enriched for cell-type identity TFBSs. Conversely, cCREs gaining accessibility throughout life have a lower abundance of cell identity TFBSs but elevated activator protein 1 (AP-1) levels. We implicate TF redistribution toward these AP-1 TFBS-rich cCREs, in synergy with mild downregulation of cell identity TFs, as driving early-life cCRE accessibility loss and altering developmental and metabolic gene expression. Such remodeling can be triggered by elevating AP-1 or depleting repressive H3K27me3. We propose that AP-1-linked chromatin opening drives organismal maturation by disrupting cell identity TFBS-rich cCREs, thereby reprogramming transcriptome and cell function, a mechanism hijacked in aging through ongoing chromatin opening.

Long COVID as a disease of accelerated biological aging: An opportunity to translate geroscience interventions

It has been four years since long COVID-the protracted consequences that survivors of COVID-19 face-was first described. Yet, this entity continues to devastate the quality of life of an increasing number of COVID-19 survivors without any approved therapy and a paucity of clinical trials addressing its biological root causes. Notably, many of the symptoms of long COVID are typically seen with advancing age. Leveraging this similarity, we posit that Geroscience-which aims to target the biological drivers of aging to prevent age-associated conditions as a group-could offer promising therapeutic avenues for long COVID. Bearing this in mind, this review presents a translational framework for studying long COVID as a state of effectively accelerated biological aging, identifying research gaps and offering recommendations for future preclinical and clinical studies.

Interplay Between Skeletal and Hematopoietic Cells in the Bone Marrow Microenvironment in Homeostasis and Aging

PURPOSE OF THE REVIEW

In this review, we discuss the most recent scientific advances on the reciprocal regulatory interactions between the skeletal and hematopoietic stem cell niche, focusing on immunomodulation and its interplay with the cell's mitochondrial function, and how this impacts osteoimmune health during aging and disease.

RECENT FINDINGS

Osteoimmunology investigates interactions between cells that make up the skeletal stem cell niche and immune system. Much work has investigated the complexity of the bone marrow microenvironment with respect to the skeletal and hematopoietic stem cells that regulate skeletal formation and immune health respectively. It has now become clear that these cellular components cooperate to maintain homeostasis and that dysfunction in their interaction can lead to aging and disease. Having a deeper, mechanistic appreciation for osteoimmune regulation will lead to better research perspective and therapeutics with the potential to improve the aging process, skeletal and hematologic regeneration, and disease targeting.

The role of cellular senescence in neurodegenerative diseases

Increasing evidence has revealed that cellular senescence drives NDs, including Alzheimer's disease (AD) and Parkinson's disease. Different senescent cell populations secrete senescence-associated secretory phenotypes (SASP), including matrix metalloproteinase-3, interleukin (IL)-1α, IL-6, and IL-8, which can harm adjacent microglia. Moreover, these cells possess high expression levels of senescence hallmarks (p16 and p21) and elevated senescence-associated β-galactosidase activity in in vitro and in vivo ND models. These senescence phenotypes contribute to the deposition of β-amyloid and tau-protein tangles. Selective clearance of senescent cells and SASP regulation by inhibiting p38/mitogen-activated protein kinase and nuclear factor kappa B signaling attenuate β-amyloid load and prevent tau-protein tangle deposition, thereby improving cognitive performance in AD mouse models. In addition, telomere shortening, a cellular senescence biomarker, is associated with increased ND risks. Telomere dysfunction causes cellular senescence, stimulating IL-6, tumor necrosis factor-α, and IL-1β secretions. The forced expression of telomerase activators prevents cellular senescence, yielding considerable neuroprotective effects. This review elucidates the mechanism of cellular senescence in ND pathogenesis, suggesting strategies to eliminate or restore senescent cells to a normal phenotype for treating such diseases.

Aging promotes metabolic dysfunction-associated steatotic liver disease by inducing ferroptotic stress

Susceptibility to the biological consequences of aging varies among organs and individuals. We analyzed hepatocyte transcriptomes of healthy young and aged male mice to generate an aging hepatocyte gene signature, used it to deconvolute transcriptomic data from humans and mice with metabolic dysfunction-associated liver disease, validated findings with functional studies in mice and applied the signature to transcriptomic data from other organs to determine whether aging-sensitive degenerative mechanisms are conserved. We discovered that the signature enriches in diseased livers in parallel with degeneration. It is also enriched in failing human hearts, diseased kidneys and pancreatic islets from individuals with diabetes. The signature includes genes that control ferroptosis. Aged mice develop more hepatocyte ferroptosis and liver degeneration than young mice when fed diets that induce metabolic stress. Inhibiting ferroptosis shifts the liver transcriptome of old mice toward that of young mice and reverses aging-exacerbated liver damage, identifying ferroptosis as a tractable, conserved mechanism for aging-related tissue degeneration.

Associations between epigenetic age acceleration and longitudinal measures of psychosocioeconomic stress and status

Relationships between epigenetic aging markers and psychosocial variables such as socioeconomic status and stress have been well-documented, but are often examined cross-sectionally or retrospectively, and have tended to focus on objective markers of SES or major life events. Here, we examined associations between psychosocial variables, including measures of socioeconomic status and social stress, and epigenetic aging markers in adulthood, using longitudinal data spanning three decades from the Midlife in the United States (MIDUS) study. The largest effects were observed for epigenetic markers of change in health, such as DunedinPACE and GrimAge, and for associations involving education, income, net assets, general social stress, inequality-related stress, and financial stress. Analyses of polygenic indices suggests that at least in the case of education, the link to epigenetic aging cannot be accounted for by common genetic variants.

Parental status and markers of brain and cellular age: A 3D convolutional network and classification study

Recent research shows prominent effects of pregnancy and the parenthood transition on structural brain characteristics in humans. Here, we present a comprehensive study of how parental status and number of children born/fathered links to markers of brain and cellular ageing in 36,323 UK Biobank participants (age range 44.57-82.06 years; 52% female). To assess global effects of parenting on the brain, we trained a 3D convolutional neural network on T1-weighted magnetic resonance images, and estimated brain age in a held-out test set. To investigate regional specificity, we extracted cortical and subcortical volumes using FreeSurfer, and ran hierarchical clustering to group regional volumes based on covariance. Leukocyte telomere length (LTL) derived from DNA was used as a marker of cellular ageing. We employed linear regression models to assess relationships between number of children, brain age, regional brain volumes, and LTL, and included interaction terms to probe sex differences in associations. Lastly, we used the brain measures and LTL as features in binary classification models, to determine if markers of brain and cellular ageing could predict parental status. The results showed associations between a greater number of children born/fathered and younger brain age in both females and males, with stronger effects observed in females. Volume-based analyses showed maternal effects in striatal and limbic regions, which were not evident in fathers. We found no evidence for associations between number of children and LTL. Classification of parental status showed an Area under the ROC Curve (AUC) of 0.57 for the brain age model, while the models using regional brain volumes and LTL as predictors showed AUCs of 0.52. Our findings align with previous population-based studies of middle- and older-aged parents, revealing subtle but significant associations between parental experience and neuroimaging-based surrogate markers of brain health. The findings further corroborate results from longitudinal cohort studies following parents across pregnancy and postpartum, potentially indicating that the parenthood transition is associated with long-term influences on brain health.

The impact of COVID-19 on "biological aging"

The global impact of the SARS-CoV-2 pandemic has been unprecedented, posing a significant public health challenge. Chronological age has been identified as a key determinant for severe outcomes associated with SARS-CoV-2 infection. Epigenetic age acceleration has previously been observed in various diseases including human immunodeficiency virus (HIV), Cytomegalovirus (CMV), cardiovascular diseases, and cancer. However, a comprehensive review of this topic is still missing in the field. In this review, we explore and summarize the research work focusing on biological aging markers, i.e., epigenetic age and telomere attrition in COVID-19 patients. From the reviewed articles, we identified a consistent pattern of epigenetic age dysregulation and shortened telomere length, revealing the impact of COVID-19 on epigenetic aging and telomere attrition.

CheekAge: a next-generation buccal epigenetic aging clock associated with lifestyle and health

Epigenetic aging clocks are computational models that predict age using DNA methylation information. Initially, first-generation clocks were developed to make predictions using CpGs that change with age. Over time, next-generation clocks were created using CpGs that relate to both age and health. Since existing next-generation clocks were constructed in blood, we sought to develop a next-generation clock optimized for prediction in cheek swabs, which are non-invasive and easy to collect. To do this, we collected MethylationEPIC data as well as lifestyle and health information from 8045 diverse adults. Using a novel simulated annealing approach that allowed us to incorporate lifestyle and health factors into training as well as a combination of CpG filtering, CpG clustering, and clock ensembling, we constructed CheekAge, an epigenetic aging clock that has a strong correlation with age, displays high test-retest reproducibility across replicates, and significantly associates with a plethora of lifestyle and health factors, such as BMI, smoking status, and alcohol intake. We validated CheekAge in an internal dataset and multiple publicly available datasets, including samples from patients with progeria or meningioma. In addition to exploring the underlying biology of the data and clock, we provide a free online tool that allows users to mine our methylomic data and predict epigenetic age.