Family environments and leukocyte transcriptome indicators of a proinflammatory phenotype in children and parents

Social relationships and epigenetic aging in older adulthood: Results from the Health and Retirement Study

Growing evidence suggests that social relationship quality can influence age-related health outcomes, although how the quality of one's relationships directly relates to the underlying aging process is less clear. We hypothesized that the absence of close relationships as well as lower support and higher strain within existing relationships would be associated with an accelerated epigenetic aging profile among older adults in the Health and Retirement Study. Adults (N = 3,647) aged 50-100 years completed ratings of support and strain in relationships with their spouse, children, other family members, and friends. They also provided a blood sample that was used for DNA methylation profiling to calculate a priori-specified epigenetic aging measures: Horvath, Hannum, PhenoAge, GrimAge, and Dunedin Pace of Aging methylation (DunedinPoAm38). Generalized linear models that adjusted for chronological age, sex, and race/ethnicity and applied a false discovery rate correction revealed that the absence of marital and friend relationships related to an older GrimAge and faster DunedinPoAm38. Among those with existing relationships, lower support from a spouse, child, other family, and friends and higher strain with friends related to an older PhenoAge and GrimAge and faster DunedinPoAm38. In secondary analyses that further adjusted for socioeconomic and lifestyle factors, lower support from other family members and friends was associated with greater epigenetic aging. Findings suggest that the absence of close relationships and lower support within existing relationships-particularly with family members and friends-relate to accelerated epigenetic aging in older adulthood, offering one mechanism through which social relationships might influence risk for age-related declines and disease.

Ozone Pollution, Perceived Support at Home, and Asthma Symptom Severity in the Adolescent Sample of the California Health Interview Survey

BACKGROUND

Outdoor air pollution, including ozone (O₃) pollution, and childhood family environments may interact and impact asthma exacerbations in children. Previous epidemiology studies have primarily focused on stress in the home, rather than support, and whether psychosocial factors modify the association between pollution and health outcomes, rather than whether pollution exposure modifies associations between psychosocial factors and health outcomes.

METHODS

Data from the cross-sectional 2003 representative, population-based California Health Interview Survey were linked with air quality monitoring data on O₃ pollution from the California Air Resources Board. Adolescents (N = 209) ages 12-17 who reported an asthma diagnosis and lived within 5 mi of the nearest air monitoring station had linked O₃ data for a 12-month period preceding the survey interview date. Adolescents reported perceived available support from an adult at home and frequency of asthma symptoms.

RESULTS

In unadjusted models, for adolescents living in high O₃ pollution regions, greater perceived support was related to lower asthma symptom frequency. Follow-up analyses suggested that the most plausible interpretation of the interaction was that O₃ exposure modified the association between perceived support and symptom frequency. O₃ × perceived support interactions were not statistically significant after adjusting for covariates.

CONCLUSIONS

These data provide preliminary evidence that the association between the lack of support in the home environment and worse asthma symptoms may be stronger in areas with higher O₃ exposure. Future work may benefit from incorporating personal pollution exposure assessments, comprehensive family environment assessments, and longitudinal follow-up of asthma exacerbations over time.

Why and how does early adversity influence development? Toward an integrated model of dimensions of environmental experience

Two extant frameworks - the harshness-unpredictability model and the threat-deprivation model - attempt to explain which dimensions of adversity have distinct influences on development. These models address, respectively, why, based on a history of natural selection, development operates the way it does across a range of environmental contexts, and how the neural mechanisms that underlie plasticity and learning in response to environmental experiences influence brain development. Building on these frameworks, we advance an integrated model of dimensions of environmental experience, focusing on threat-based forms of harshness, deprivation-based forms of harshness, and environmental unpredictability. This integrated model makes clear that the why and the how of development are inextricable and, together, essential to understanding which dimensions of the environment matter. Core integrative concepts include the directedness of learning, multiple levels of developmental adaptation to the environment, and tradeoffs between adaptive and maladaptive developmental responses to adversity. The integrated model proposes that proximal and distal cues to threat-based and deprivation-based forms of harshness, as well as unpredictability in those cues, calibrate development to both immediate rearing environments and broader ecological contexts, current and future. We highlight actionable directions for research needed to investigate the integrated model and advance understanding of dimensions of environmental experience.

Psychosocial experiences modulate asthma-associated genes through gene-environment interactions

Social interactions and the overall psychosocial environment have a demonstrated impact on health, particularly for people living in disadvantaged urban areas. Here, we investigated the effect of psychosocial experiences on gene expression in peripheral blood immune cells of children with asthma in Metro Detroit. Using RNA-sequencing and a new machine learning approach, we identified transcriptional signatures of 19 variables including psychosocial factors, blood cell composition, and asthma symptoms. Importantly, we found 169 genes associated with asthma or allergic disease that are regulated by psychosocial factors and 344 significant gene-environment interactions for gene expression levels. These results demonstrate that immune gene expression mediates the link between negative psychosocial experiences and asthma risk.

Annual Research Review: Social relationships and the immune system during development

A child's social relationships serve critical functions during development. The interface between a child's social world and their immune system, particularly innate immunity, which helped children survive in the face of infections, nutritional scarcity, and violence throughout human history, is the focus of this Annual Research Review. This article reviews the state of research on social relationships and innate immune inflammation during childhood. Warmth and rejection in childhood social relationships, as well as physical trauma and unpredictable social environments, were not consistently related to circulating inflammatory markers such as interleukin-6 and C-reactive protein during childhood. Instead, links between social environments and inflammation were observed in studies that focus on children with greater background risk factors, such as low family socioeconomic status, family history of mood disorders, or presence of chronic interpersonal stressors combined with acute episodic stressors. In addition, studies on worse childhood social environments and greater inflammation in adulthood were more consistent. Warmth and rejection in the social environment may be related to sensitivity of immune cells to the anti-inflammatory actions of glucocorticoids, though this is primarily observed in adolescent women at risk for depression. Additional mechanistic evidence suggests that greater warmth and less rejection are related to processes that regulate inflammation, including greater expression of the glucocorticoid receptor gene and lower expression of genes that are responsive to the pro-inflammatory transcription factor NF-kappa B. The article concludes by discussing implications of the interface between a child's social relationships and inflammation for mental health and other recent (on evolutionary timescales) health threats, as well as recommendations for future research, and recommendations for researchers interested in integrating inflammatory measures in developmental research.

Genes, Environments, and Time: The Biology of Adversity and Resilience

Exposures to adverse environments, both psychosocial and physicochemical, are prevalent and consequential across a broad range of childhood populations. Such adversity, especially early in life, conveys measurable risk to learning and behavior and to the foundations of both mental and physical health. Using an interactive gene-environment-time (GET) framework, we survey the independent and interactive roles of genetic variation, environmental context, and developmental timing in light of advances in the biology of adversity and resilience, as well as new discoveries in biomedical research. Drawing on this rich evidence base, we identify 4 core concepts that provide a powerful catalyst for fresh thinking about primary health care for young children: (1) all biological systems are inextricably integrated, continuously "reading" and adapting to the environment and "talking back" to the brain and each other through highly regulated channels of cross-system communication; (2) adverse environmental exposures induce alterations in developmental trajectories that can lead to persistent disruptions of organ function and structure; (3) children vary in their sensitivity to context, and this variation is influenced by interactions among genetic factors, family and community environments, and developmental timing; and (4) critical or sensitive periods provide unmatched windows of opportunity for both positive and negative influences on multiple biological systems. These rapidly moving frontiers of investigation provide a powerful framework for new, science-informed thinking about health promotion and disease prevention in the early childhood period.

Relationship closeness buffers the effects of perceived stress on transcriptomic indicators of cellular stress and biological aging marker p16INK4a

Chronic stress can accelerate biological aging, offering one mechanism through which stress may increase age-related disease risk. Chronic activation of the sympathoadrenal system increases cellular energy production, resulting in cell stress that can initiate cellular senescence, a permanent state of cell growth arrest. Our previous research linked psychosocial stress with increased expression of senescence marker p16^INK4a; however, less is known about the role of protective psychosocial factors in biological aging. We examined relationship closeness (perceived interconnectedness with one's spouse) as a protective buffer of the effects of stress on expression of the p16^INK4a-encoding gene (CDKN2A) and transcription control pathways activated under cell stress. Seventy parents (M_age=43.2) completed interview-based and questionnaire measures of psychosocial stress and relationship closeness. Blood samples assessed CDKN2A expression and inferred activity of a priori-selected transcription factors Nrf2 and heat shock factors (HSFs) via genome-wide transcriptome profiling. Random intercept models adjusting for age, sex, and ethnicity/race revealed that perceived stress was associated with elevated CDKN2A expression for parents with low but not high closeness. Secondary bioinformatics analyses linked the interaction of perceived stress and relationship closeness to Nrf2 and HSF-1 activity. Findings identify relationship closeness as a protective factor that may buffer the impact of stress on cellular stress and senescence pathways.

Toward a Mechanistic Understanding of Links Between Close Relationships and Physical Health

Although researchers have made great strides in identifying links between close relationship processes and physical health, we know less about the psychological and behavioral mechanisms underlying these links. As we move toward considering relationships as a public health issue, understanding mechanistic pathways in relationships–health links is crucial for designing efficient and effective interventions. In this review, we outline criteria for establishing a construct as a relationships–health mechanism. We then discuss how best to test potential mechanisms of relationships–health links and identify some promising mechanism candidates on the basis of initial evidence (emotion, attachment, sleep, and substance abuse). We conclude by recommending key directions for future research.

Chronic stress exposure and daily stress appraisals relate to biological aging marker p16INK4a

Previous research has linked exposure to adverse social conditions with DNA damage and accelerated telomere shortening, raising the possibility that chronic stress may impact biological aging pathways, ultimately increasing risk for age-related diseases. Less clear, however, is whether these stress-related effects extend to additional hallmarks of biological aging, including cellular senescence, a stable state of cell cycle arrest. The present study aimed to investigate associations between psychosocial stress and two markers of cellular aging-leukocyte telomere length (LTL) and cellular senescence signal p16INK4a. Seventy-three adults (Mage = 43.0, SD = 7.2; 55% female) with children between 8-13 years of age completed interview-based and questionnaire measures of their exposures to and experiences of stress, as well as daily reports of stress appraisals over an 8-week diary period. Blood samples were used to assess markers of cellular aging: LTL and gene expression of senescent cell signal p16INK4a (CDKN2A). Random effects models covarying for age, sex, ethnicity/race, and BMI revealed that participants with greater chronic stress exposure over the previous 6 months (b = 0.011, p =  .04), perceived stress (b = 0.020, p <  .001), and accumulated daily stress appraisals over the 8-week period (b = 0.013, p =  .02) showed increased p16INK4a. No significant associations with LTL were found. These findings extend previous work on the impact of stress on biological aging by linking chronic stress exposure and daily stressful experiences to an accumulation of senescent cells. Findings also support the hypothesis that chronic stress is associated with accelerated aging by inducing cellular senescence, a common correlate of age-related diseases.

Developmental Adaptation to Stress: An Evolutionary Perspective

The assumption that early stress leads to dysregulation and impairment is widespread in developmental science and informs prevailing models (e.g., toxic stress). An alternative evolutionary–developmental approach, which complements the standard emphasis on dysregulation, proposes that early stress may prompt the development of costly but adaptive strategies that promote survival and reproduction under adverse conditions. In this review, we survey this growing theoretical and empirical literature, highlighting recent developments and outstanding questions. We review concepts of adaptive plasticity and conditional adaptation, introduce the life history framework and the adaptive calibration model, and consider how physiological stress response systems and related neuroendocrine processes may function as plasticity mechanisms. We then address the evolution of individual differences in susceptibility to the environment, which engenders systematic person–environment interactions in the effects of stress on development. Finally, we discuss stress-mediated regulation of pubertal development as a case study of how an evolutionary–developmental approach can foster theoretical integration.

Aspects of the parent-child relationship and parent metabolic outcomes

Much is known about the effect of parent-child relationships on child health; less is known about how parent-child relationships influence parent health. To assess the association between aspects of the parent-child relationship and parent metabolic outcomes, and whether these associations are moderated by parent gender. Five metabolic outcomes (systolic and diastolic blood pressure, heart rate, total cholesterol and glycated hemoglobin) were assessed among 261 parents (45.83 ± 5.50 years) of an adolescent child (14.57 ± 1.072 years). Parents completed questionnaires assessing their child's hassles and the quality of their days with their child. Parents' perceptions of their child's hassles were associated with parent heart rate (B = 2.954, SE = 1.267, p = 0.021) and cholesterol (B = 0.028, SE = 0.011, p = 0.010), such that greater perceived child hassles were associated with higher heart rate and cholesterol levels, on average. These associations were not moderated by parent gender (all ps > 0.30). Parent report of their day with their child was not associated with parent metabolic outcomes (all ps > 0.20). Parent gender moderated the association between parent report of their day with their child and parent systolic blood pressure (B = 13.861, SE = 6.200, p = 0.026), such that less positive reports were associated with higher blood pressure readings among fathers, but not mothers. This study suggests that parent metabolic health may in part be influenced by aspects of the parent-child relationship.