Energy Metabolism Focused Analysis of Sexual Dimorphism in Biological Aging and Hypothesized Sex-specificity in Sirtuin Dependency.

The process of biological aging or senescence refers to the gradual loss of homeostasis and subsequent loss of function - leading to higher chances of mortality. Many mechanisms and driving forces have been suggested to facilitate the evolution of a molecular circuit acting as a trade-off between survival and proliferation, resulting in senescence. A major observation on biological aging and longevity in humans and model organisms is the prevalence of significant sexual divergence in the onset, mechanisms and effects of aging associated processes.

Are there Different Kinds of Aging?

Background: Most syndromes of accelerated aging are caused by mutations affecting the integrity of the genetic material. Among them, the most studied is Werner's syndrome, "adult progeria", caused by a recessive autosomal mutation with a frequency of 1 in 10 million, which affects a helicase involved in DNA repair. In Werner syndrome, there is a loss of heterochromatin, though the stability of heterochromatin is also affected in "normal" aging.

A new hypothesis of aging.

Introduction And Aims: There are over 300 hypotheses of aging, but none of them has enough predictive power to explain most experiments and observations on this process. On the basis of a critical analysis of the most relevant data on aging, especially on the factors that influences its rhythm, we present a new hypothesis, as well as the way the hypothesis' predictions explain some of the phylogenetic implications of the aging process.

Methods: The hypothesis starts from a new, biochemical view on evolution and the behavior of living matter.