Age and homeostasis

Abstract

Homeostasis is the ability of the body to maintain sufficient for life permanence of structure and function. A contradiction is that the essence of life is inevitable changes in the structure and function. The most common homeostasis violator is oxidative stress. Numerous genes triggered by Nrf2, NFκB, TFAM, and PGC1α transcription factors are involved in neutralizing the action of oxidative stress. The adaptive response is induced not only by oxidative stress but also by heat shock, glycemic stress, cold shock, osmotic stress, exhastion, starvation, mechanical stress, antigenic impact, and emotional or psychological stress. In stress, cells accumulate products of incomplete proteolysis, aggregates. The homeostatic response is evident as increased content of chaperones that contribute to the proper folding of proteins, and proteasomes that destroy the aggregates. However, the capability for an adequate response to stress declines with age, and the range of adaptive homeostasis modulation narrows. The probability of going beyond this narrowed range and of cell death is increasing.