Almost half of American adults over 60 years old report being lonely, a condition that can have a major impact on health and mortality risk in later life. Adults with weak social relationships experience a 50% higher mortality rate than more socially integrated adults?an effect on par with that of smoking, obesity, or alcoholism. One explanation for this association is if better social integration increases resilience against stressful experiences, a hypothesis known as ?stress buffering.? Yet despite the importance of social integration for human health, the behavioral and molecular mechanisms that mediate its potential role in stress buffering remain poorly understood, limiting its practical application to improving resilience during aging. The objective of the proposed study is to identify the genomic mechanisms that link social integration to stress sensitivity and inflammation during acute stress. If a main benefit of SI is to buffer against acute stress, I hypothesize that low levels of social integration will be associated with dysregulation of the gene regulatory response to acute stress. To test this hypothesis, I will leverage the advantages of studying rhesus macaques, a well-established animal model for human aging and social behavior. I propose a two-pronged approach that combines experimental manipulations of the social environment (Aims 1 and 3) with studies of free-ranging macaques (Aim 2), thus yielding insight into the relationship between acute stress and gene regulation in both a controlled setting and in a more natural environment. In both contexts, I will combine genome-wide gene expression, DNA methylation, and chromatin accessibility measurements to characterize the genomic pathways associated with social integration and its relationship with the acute stress response. I will also test whether these relationships are exaggerated for older animals, and whether the presence of a close social partner can enhance resilience to psychosocial stress. At its conclusion, this project will yield a detailed understanding of how social integration impacts gene regulation in pathways that become dysregulated with age and whether social support can buffer against acute stressors at the genomic level. Together, these results will advance our understanding of the mechanisms through which social integrations promotes resilience in the elderly. In addition, the proposed program of mentored training activities will allow me to develop a strong, independent research career in aging, focused on the nexus of aging, social behavior, and genomics.

Public Health Relevance

Older adults who are more socially integrated are healthier and live longer, possibly due to an improved ability to cope with acute stress ? a hypothesis known as ?stress buffering?. This project investigates how variation in social integration alters gene regulation in response to an acute stressor. Its results will greatly advance our understanding of the role that the quality and quantity of interpersonal relationships play in resilience during healthy aging.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Career Transition Award (K99)
Project #
5K99AG051764-02
Application #
9326108
Study Section
Neuroscience of Aging Review Committee (NIA)
Program Officer
Gerald, Melissa S
Project Start
2016-08-15
Project End
2017-09-15
Budget Start
2017-07-15
Budget End
2017-09-15
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Duke University
Department
Type
Organized Research Units
DUNS #
044387793
City
Durham
State
NC
Country
United States
Zip Code
27705
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Snyder-Mackler, Noah; Sanz, JoaquĆ­n; Kohn, Jordan N et al. (2016) Social status alters immune regulation and response to infection in macaques. Science 354:1041-1045