The Skin and Inflamm-Aging

SIMPLE SUMMARY: Aging affects all cells of the body, leading to impaired system function. Although scientists are beginning to identify some mechanisms underlying the aging process, a complete understanding remains elusive. One characteristic of aged individuals is chronic low-level inflammation throughout the body. Since inflammation induces oxidative stress and other effects that can impact proper system functioning over time, this chronic inflammation is thought to promote aging, called inflamm-aging. The cause of inflamm-aging is unclear but likely involves immune system malfunction and various other age-related alterations. Excessive inflammation of the skin, the largest organ of the body, can result in widespread effects on other systems, as is seen with inflammatory skin diseases such as psoriasis and atopic dermatitis. An important function of skin is to serve as a barrier to prevent the entry of environmental insults, such as microorganisms, and to retain water and other important substances inside the body. Disruption of this barrier results in skin inflammation that can impact the whole individual. It is known that, with age, our skin becomes less able to maintain the barrier. Therefore, we propose and discuss evidence for the idea that a poorly functioning skin barrier contributes to inflamm-aging. ABSTRACT: With its unique anatomical location facing both the external and internal environment, the skin has crucial functions, including shielding the body from damage caused by ultraviolet radiation and chemicals, preventing water loss, acting as a primary barrier against pathogens, participating in metabolic processes like vitamin D production and temperature control and relaying information to the body through sensory and proprioceptor nerves. Like all organ systems, skin is known to undergo multiple changes with aging. A better understanding of the mechanisms that mediate aging-related skin dysfunction may allow the creation of targeted therapeutics that have beneficial effects not only on aged skin but also on other organs and tissues that experience a loss of or decline in function with aging. The skin is the largest organ of the body and can contribute to serum inflammatory mediator levels. One alteration known to occur with age is an impairment of skin barrier function; since disruption of the barrier is known to induce inflammation, skin may be a major contributor to the sustained, sub-clinical systemic inflammation associated with aging. Such “inflamm-aging” may underlie many of the deleterious changes observed in aged individuals. This review explores the role of age-related skin changes, skin inflammation and inflamm-aging.