Subhash Katewa (Kapahi lab, Buck Institute) talked about the metabolic adaptations that occur in flies whose lifespan is being extended by dietary restriction (DR). Katewa is studying translational control in DR using a method called translational profiling, which uses the number of ribosomes bound to each mRNA as an index of translational activity (more ribosomes = more translation). He found that DR increases translation of messages that encode a variety of mitochondrial functions; this observation led to some interesting findings about the differential turnover of triglycerides in DR vs ad libitum flies.

Adam Freund (Campisi lab, Buck Institute) spoke about the sources of age-related inflammation, focusing on the senescence-associated secretory phenotype (SASP). Freund has elucidated mechanisms of SASP control that intermediate between the most upstream events in senescence (DNA damage) and its downstream effects (secretion of inflammatory factors). I have it on good authority that he has a completed manuscript on the subject, hopefully to be publshed soon, so I won’t say more about his story here. (Mr. Freund happens to be my baymate.)

Dario Valenzano (Brunet lab, Stanford University) is studying the genetic architecture of longevity in a short-lived fish Nothobranchius furzeri, the shortest-living vertebrate that can be reared in captivity. As a graduate student, Valenzano developed a system of biomarkers for tracking the progress of aging in skin, brain and other tissues – not only physical markers like the senescence-associated beta-galactosidase but also behavioral markers that change over the lifespan. He is now proceeding to map the longevity-associated genes in N. furzeri and testing the sufficiency of the genes he finds. Early results indicate that short-lived and long-lived fish are dying from different causes, as evidenced by a bimodal distribution of death rate vs. age.

Adolfo Sánchez-Blanco (Kim lab, Stanford University Medical School) described the “molecular odometer” for aging in the worm C. elegans. He began with the observation that lifespan is variable, even among clonally identical individuals kept under identical conditions. With genetics and environment taken out of the picture, what makes some individuals live longer than others? In order to address this question, SB had to develop a molecular marker (e.g., promoter activity of some gene) that measures physiological age (as opposed to chronological age), and then determine whether the expression level of that marker in individual worms is predictive of lifespan. SB has identified several such genes whose expression at middle age strongly predicts remaining lifespan. He is now actively looking for interventions that abolish the correlation between marker expression and longevity: if the marker gene’s activity is serving to overcome the life-shortening effect of some stress, then removing that stress will not necessarily abolish the variability in the marker, but will eliminate the correlation between marker levels and lifespan. (This is a subtle but important logical issue; I would have thought that one should look for interventions that drove the population distribution of marker levels toward the favorable side of the distribution. It was clear from questions that a lot of audience members had trouble with this logic, and I’m still not sure I understand it myself.)

(next session)

Ouroboros

One approach to understanding the senescent growth arrest is to examine the factors that are required for the division of young cells and to determine whether the senescent cells are able to respond to these factors. Any defect in their response would presumably shed light on the mechanism of the growth arrest. In virtually all cell types, cell division is regulated by the presence of growth factors. Growth factors are small proteins that bind to specific receptors on the surface of cells. The receptors for growth factors contain intrinsic enzymatic activity that is activated by growth factor binding. (more…)

An increase in the concentration of free radicals, measured using electron spin resonance (ESR) spectroscopy, can reflect the degree of oxidative stress. An in vivo ESR spectroscopy technique has been developed to measure free radical reactions even in the whole animal non-invasively using nitroxide free radicals, which are sensitive to both redox state and ROS. Rates of penetration of nitroxide free radicals into the skin and their distribution in the skin have been measured by the ESR technique. Thus, the generation and distribution of radicals produced during normal metabolism or induced after irradiation of the skin by sunlight can be measured. (more…)

An international consensus statement on physical activity, fitness and health (Bouchard et al 1994) identifies six areas affected by physical exercise: body shape, bone strength, muscle strength, flexibility skeleton, physical fitness and motor fitness of metabolism. Other areas benefit from physical activity is cognitive function, mental health and adaptation to society. Exercise was defined as a regular activity that follows a specific pattern, and whose purpose is to achieve desirable results in terms of fitness, as a better general health or physical functioning. (more…)

The word cognizable is being used to access the features and functions of T cells which may still unknown or understood. In other words, aspects of the functioning of T cells and details of the operation that already exist and are waiting to be unveil.

The first visible effects of aging affect clonal restriction, and clonal dominance of T-cell as biomarkers of aging in the elderly (more…)

The population of man aged over 65 will exceed the number of children under 5 years old in 2040, for the first time in history, according to a study released by the Census Bureau United States, which warned of the impact that this development. It is predicted huge impact will occurs in both the developed and developing countries. Diverse area will affected by these changes in population’s composition. (more…)

The term biomarker, which is encountered with increasing frequency in the gerontological literature, is used with a variety of implicit or explicit definitions. In some contexts, a biomarker is expected to predict longevity; in other usages, it is expected to be correlated with physiological age; in still other, it is expected to be descriptive of a fundamental aspect of aging, and so on. (more…)

Biomarkers today are used by health practitioners and researchers in a variety of settings, including clinical settings, laboratories, and community-based surveys. Epidemiological studies using biomarkers have expanded our knowledge base about aging in the community, population differences in health, and the clinical significance of many biomarkers. (more…)

Aging theories cover the physiological, genetic, biochemical properties of a typical organism, and the way these properties change with time. Theories of genetic dealing with the identity of aging obesity genes, accumulation of errors in the genetic machinery, programmed senescence, and telomeres theory. Biochemical theories are concerned with generation of free radicals, the rate of living, energy metabolism, and the health of mitochondria. While Theory of Physiological deal most entirely with the endocrine system and the purpose of hormones in governing the rate of cellular aging. (more…)