TITLE:
Review of Major Theories of Skin Aging
AUTHORS:
Alfredo Gragnani, Sarita Mac Cornick, Verônica Chominski, Samuel Marcos Ribeiro de Noronha, Silvana Aparecida Alves Corrêa de Noronha, Lydia Masako Ferreira
KEYWORDS:
Aging, Genetics, Reactive Oxygen Species, Telomerase, Cell Senescence
JOURNAL NAME:
Advances in Aging Research,
Vol.3 No.4,
August
29,
2014
ABSTRACT: Here we aim to describe each factor that leads to skin aging and describe their mechanisms. A PubMed database searches (from January 2004 to March 2014) using aging and skin as searched terms. There are substantial evidences showing that aging is associated with damage from free radicals represented by various reactive oxygen species (ROS). Mitochondria are producers and also targets of oxidative stress. The cycle of mitochondrial dysfunction can trigger the aging process. In the cellular senescence and telomeres theory, the diploid cells exhibit a limited proliferation potential. After a finite number of divisions, they enter a state of senescence with a stop replication in cell proliferation. It is suggested that aging is associated mainly with hyper-regulation of apoptosis. Obesity presumably accelerates the process of aging, which is aggravated by smoking. And the influence of the environment, called solar UV irradiation is of considerable importance to skin aging. There are several mechanisms that trigger the natural aging process and contribute to age-related changes, including oxidative stress theory of free radicals, the mitochondrial dysfunction, telomere shortening, UV radiation and other mechanisms that taken together or alone may or not accelerate the change in skin.