Insights on the role of l-lactate as a signaling molecule in skin aging

Abstract

Abstractl-lactate is a catabolite from the anaerobic metabolism of glucose, which plays a paramount role as a signaling molecule in various steps of the cell survival. Its activity, as a master tuner of many mechanisms underlying the aging process, for example in the skin, is still presumptive, however its crucial position in the complex cross-talk between mitochondria and the process of cell survival, should suggest that l-lactate may be not a simple waste product but a fine regulator of the aging/survival machinery, probably via mito-hormesis. Actually, emerging evidence is highlighting that ROS are crucial in the signaling of skin health, including mechanisms underlying wound repair, renewal and aging. The ROS, including superoxide anion, hydrogen peroxide, and nitric oxide, play both beneficial and detrimental roles depending upon their levels and cellular microenvironment. Physiological ROS levels are essential for cutaneous health and the wound repair process. Aberrant redox signaling activity drives chronic skin disease in elderly. On the contrary, impaired redox modulation, due to enhanced ROS generation and/or reduced levels of antioxidant defense, suppresses wound healing via promoting lymphatic/vascular endothelial cell apoptosis and death. This review tries to elucidate this issue.

Associations between genetically predicted sex and growth hormones and facial aging in the UK Biobank: a two−sample Mendelian randomization study

“…Human facial aging is increasingly being studied; however, to our knowledge, no studies have investigated the roles of sex hormones in facial aging using GWAS data. Sex hormone levels are thought to fluctuate with age and to be associated with facial aging, and testosterone and bioavailable testosterone levels decline with age, particularly in men ( 26 ). Estradiol levels also decline with age, with a rapid decline in women after menopause ( 27 , 28 ).…”

Exercise intensity-dependent lactate elevation in skin interstitial fluid and its long-lasting effect

“…In addition, a recent study suggested that regular exercise rejuvenated aging skin conditions 35 . A recent review highlighted that lactate acts as a signaling molecule that interacts with mitochondrial biogenesis and turnover and tunes the ability of cells to respond to stressors 36 . Therefore, these physiological adaptations in skin tissue might occur due to lactate accumulation after exercise.…”

“…The present results of skin ISF lactate dynamics in this study can provide new hypotheses. Growing evidence suggests that chronic exercise improved skin conditions (2,3), and lactate acts as a signaling molecule that interacts with mitochondrial biogenesis and turnover and tunes the ability of cells to respond to stressors (9). These findings and the present results suggest that the beneficial physiological adaptation of skin tissue to chronic exercise might be due to the accumulated effects of acute exercise-induced long-lasting lactate elevation in the skin ISF.…”

Ozone in the adjunct medical treatment. The round personality of a molecule with hormetic properties

“…In aging, ozone exerts its ability in eliciting pro-survival mechanisms, which usually are induced by low doses of this compound, 23 and which may activate complex regulatory systems involving mitochondria turnover and other regulatory molecules usually associated with stress such as H 2 O 2 and lactate. 24 Most of the finesse in using ozone in the so-called "ozone therapy", 25,26 which is not a therapy but a medical adjunct treatment, lies on the physician's ability in tailoring sound and effective protocols with proper ozone dosages and sound, standardized administration routes. The purpose is to elicit the production of ROS and other mediators, such as 4-HNE, in a way able to induce their "signaling" property, rather than intrinsic toxic activity.…”

“…In aging, ozone exerts its ability in eliciting pro-survival mechanisms, which usually are induced by low doses of this compound, 23 and which may activate complex regulatory systems involving mitochondria turnover and other regulatory molecules usually associated with stress such as H 2 O 2 and lactate. 24…”