Adiponectin multimers and metabolic syndrome traits: relative adiponectin resistance in African Americans.

African Americans (AAs) tend to have lower total adiponectin levels compared to European Americans (EA); however, it is not known whether race affects adiponectin multimer distribution and their relationships to metabolic traits. We measured total adiponectin, high molecular weight (HMW), low molecular weight (LMW) (i.e.

Sublethal mitochondrial stress with an attendant stoichiometric augmentation of reactive oxygen species may precipitate many of the beneficial alterations in cellular physiology produced by caloric restriction, intermittent fasting, exercise and dietary phytonutrients: "Mitohormesis" for health and vitality.

The precise mechanistic sequence producing the beneficial effects on health and lifespan seen with interventions as diverse as caloric restriction, intermittent fasting, exercise, and consumption of dietary phytonutrients is still under active characterization, with large swaths of the research community kept in relative isolation from one another. Among the explanatory models capable of assisting in the identification of precipitating elements responsible for beneficial influences on physiology seen in these states, the hormesis perspective on biological systems under stress has yielded considerable insight into likely evolutionarily consistent organizing principles functioning in all four conditions. Recent experimental findings provide the tantalizing initial lodestones for an entirely new research front examining molecular substrates of stress resistance.

RhoA, Rho kinase, JAK2, and STAT3 may be the intracellular determinants of longevity implicated in the progeric influence of obesity: Insulin, IGF-1, and leptin may all conspire to promote stem cell exhaustion.

The aging process in higher mammals is increasingly being shown to feature a potentially substantial contribution from the longitudinal deterioration of normative stem cell dynamics seen with the passage of time. The precise mechanistic sequence producing this phenomenon is not entirely understood, but recent evidence has strongly implicated intracellular downstream effectors of endocrinologic pathways thought to be engaged by the obese state, specifically the insulin, IGF-1, and leptin signaling pathways. Among the intracellular effectors of these signals, a uniquely potent influence on stem cell dynamics may be attributable to Rho/ROCK, JAK kinase activity and STAT3 activity.

Histone-deacetylase inhibitors may accelerate the aging process in stem cell-dependent mammals: stem cells, Ku70, and Drosophila at the crossroads.

The exact contribution of the sirtuin family of NAD+-dependent histone deacetylases to longevity in metazoans is, at present, not completely understood but nonetheless regarded as significant. Despite the rapidly accreting evidence solidifying the role of NAD+-dependent histone deacetylase activity in longevity-promoting experimental interventions, the utility of histone-deacetylase inhibitors in the management of a diverse group of oncologic conditions draws question to the notion of universally beneficial effects of experimental interventions designed to promote deacetylase activity. The recent determination that overexpression of any one of the seven human sirtuin deacetylases fails to extend replicative lifespan in differentiated human cells calls attention to the possibility of unforeseen complexity in the determinants of human lifespan.