The naked mole rat (Heterocephalus glaber) is a strictly subterranean, extraordinarily long-lived eusocial mammal. Although it is the size of a mouse, its maximum lifespan exceeds 30 years, making this animal the longest-living rodent. Naked mole rats show negligible senescence, no age-related increase in mortality, and high fecundity until death. In addition to delayed ageing, they are resistant to both spontaneous cancer and experimentally induced tumorigenesis. Naked mole rats pose a challenge to the theories that link ageing, cancer and redox homeostasis.
Body function rhythmicity has a key function for the regulation of internal timing and adaptation to the environment. A wealth of recent data has implicated endogenous biological rhythm generation and regulation in susceptibility to disease, longevity, cognitive performance. Concerning brain diseases, it has been established that many molecular pathways implicated in neurodegeneration are under circadian regulation. At the molecular level, this regulation relies on clock genes forming interconnected, self-sustained transcriptional/translational feedback loops.
In a long-term longitudinal study of aging in rhesus monkeys, a primary objective has been to determine the effects of aging and caloric restriction (CR) on behavioral and neural parameters. Through the use of automated devices, locomotor activity can be monitored in the home cages of the monkeys. Studies completed thus far indicate a clear age-related decline in activity consistent with such observations in many other species, including humans. However, no consistent effects of CR on activity have been observed.
A recent European Molecular Biology Laboratory Conference on Science and Society entitled "Time & Aging--Mechanisms & Meanings" fascinated scientists from different research areas as well as nonscientists. Topics discussed included not only the biological aging process but also the psychological effects of aging and social influences that affect this process.
The Editorial Board of Aging reviews research papers published in 2009, which they believe have or will have significant impact on aging research. Among many others, the topics include genes that accelerate aging or in contrast promote longevity in model organisms, DNA damage responses and telomeres, molecular mechanisms of life span extension by calorie restriction and pharmacological interventions into aging.
Across phyla, aging is associated with reduced sleep duration and efficiency. Both aging and sleep involve complex genetic architecture and diverse cell types and are heavily influenced by diet and environment. Therefore, understanding the molecular mechanisms of age-dependent changes in sleep will require integrative approaches that go beyond examining these two processes independently. The fruit fly, Drosophila melanogaster, provides a genetically amenable system for dissecting the molecular basis of these processes.
Long-term exposure to stress and its physiological mediators, in particular cortisol, may lead to impaired telomere maintenance. In this study, we examine if greater cortisol responses to an acute stressor and/or dysregulated patterns of daily cortisol secretion are associated with shorter telomere length. Twenty-three postmenopausal women comprising caregivers for dementia partners (n=14) and age- and BMI-matched non-caregivers provided home sampling of cortisol-saliva samples at waking, 30 min after waking, and bedtime, and a 12-hour overnight urine collection.
OBJECTIVE: To examine whether dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis associated with disadvantaged social position in working populations also occurs in older age groups. METHODS: This study examines the association of several indicators of social position with two measures of cortisol secretion, a product of the HPA axis. We examined the cortisol awakening response (CAR), and slope of the decline in cortisol secretion across the day.
Allostatic load, the physiological accumulation of the effects of chronic stressors, has been associated with multiple adverse health outcomes. Flattened diurnal cortisol rhythmicity is one of the prototypes of allostatic load, and has been shown to predict shorter survival among women with metastatic breast cancer. The current study compared diurnal cortisol slope in 17 breast cancer patients and 31 controls, and tested associations with variables previously found to be related to cortisol regulation, i.e, abdominal adiposity, perceived stress, social support, and explicit memory.
OBJECTIVE: Retrospective assessments of negative mood have predicted coronary artery disease development and progression. Using momentary assessment, we evaluated associations between average positive and negative mood states and diurnal mood patterns, with prevalent and incident coronary artery calcification (CAC), a measure of calcified atherosclerosis.