Glycation Stress and Photo-Aging in Skin

Abstract

Reducing sugars, such as glucose in basic solutions, and lipids by β-oxidation or peroxidation generate formyl (aldehyde) and ketone groups. Aldehydes and ketones have a highly polarized carbonyl (C=O) group, the oxygen atom of which is electronegative and may react with nucleophiles in proteins. As a result, aldehydes and ketone groups may react non-enzymatically with cell proteins by glycation, and degrade protein function. Although similar reactions have been observed in vivo, we have little information on the relationship between these reactions and age-related changes in skin.Many age-related regressive changes are actually due to protein degradation, such as posttranslational modification (proteomic denaturation), accumulation of degenerated wastes, deterioration of functional proteins, functional disorder of the tricarboxylic acid (TCA) cycle, or activation of inflammatory pathways by intracellular signals 1) . All of these changes are symptomatic of "glycation stress". Review Article Glycation Stress and Photo-Aging in Skin AbstractThis article reviews glycation stress as a factor linked to age-related diseases and functional and structural alterations of the skin. Photo-aging and glycation stress are major causes of skin deterioration. Glycation occurs when a reducing sugar, such as glucose or fructose, combines with a protein in a non-enzymatic reaction forming a glycated protein. Further reactions form advanced glycation end products (AGEs), which may accumulate in tissue. AGEs may also bind to a receptor for AGEs (RAGE), thus inducing inflammatory changes in skin and other tissues. The concept of glycation stress includes cellular and tissue responses to reducing sugars and aldehydes, not just to the production of AGEs.Glycation stress may be induced and affected by many factors, including exposure to ultraviolet light, which drastically intensifies AGE accumulation. AGEs modify skin collagen by reducing skin elasticity, and one result is wrinkle formation. AGEs accumulated in skin may be detected using auto-fluorescence (AF); our data from 136 healthy Japanese females shows the AF level is correlated with age.Glycation stress, and subsequently skin aging, may be reduced by managing levels of blood glucose, low-density lipoprotein cholesterol, and triglyceride through an appropriate diet, lifestyle, and intake of anti-glycation materials such as AGE generation inhibitors, AGE decomposers, and AGE receptor antagonists. Study of glycation stress may help identify new anti-aging treatments.

Permeation of Hydrophilic Molecules across Glycated Skin Is Differentially Regulated by the Stratum Corneum and Epidermis–Dermis

“…8,9) AGEs are generated via the non-enzymatic Maillard reaction between reducing sugars and proteins, lipids or nucleic acids. 10,11) Because glycated proteins tend to be resistant to proteinases, they accumulate in tissues with glycation stress, including due to aging and diabetes mellitus (DM). Skin accumulation of AGEs has been detected in both the epidermis and dermis.…”

What does the Anti-Aging Medical Checkup show?: Data presentation

“…In the antiaging check-up, aging is measured by five items including muscle age, vascular age, neural age, hormone age, and bone age, while risk factors of aging are measured by five items, i.e. immune 5,6) , physical and mental stress, glycative stress [7][8][9] , and lifestyles. When explaining the check-up result to examinees, it is easier for them to show it by functional age, rather than describing numerical values which might "increase or decrease".…”

“…Glycative stress is a series of phenomena where an excessive intake of glucose, fructose, fats, and alcohols modify protein, fats, DNA base molecules, and amyloid in the body, resulting in the lowering of the function to form body waste including advanced glycation end products (AGEs) or degeneration of functional proteins 7,8) . In the cases of diabetes, metabolic syndromes, lipid abnormalities, alcoholism, as well as chronic kidney diseases, glycative stress is kept so high as to cause a variety of diseases and regressive changes such as osteoporosis 18) , dementia 19) , skin aging 7) , ovarian hypofunction 2) , cataract/agerelated macular degeneration 20) , and hair aging 21) .…”

Effect of Halophilic Bacterium, Haloarcula vallismortis, Extract on UV-induced Skin Change

“…이 중 UVB는 피부 광노화의 대표적인 원인으로 피부에서 염증반응을 일으키며, 축 적된 UV자극은 피부 당화(glycation)산물을 조직에 축 적시켜 장벽손상 및 노화를 촉진시킨다 [1]. 또 표피 기 저층과 진피 상부까지 도달하여 피부각화를 지속시키 고 각질세포 및 섬유아세포의 DNA pyrimidine 잔기에 손상을 주어 cyclobutane pyrimidine dimer (CPD)를 형 성한다 [2].…”