Angiogenesis in skin aging and photoaging.
Angiogenesis, the process of generating new blood vessels, is affected by various physiological and pathological conditions of skin. The skin aging process can be divided into intrinsic aging and photoaging. With aging, cutaneous blood vessels undergo pronounced alterations. A reduction of the cutaneous microvasculature has been observed in the skin of elderly individuals. Human skin is exposed daily to solar ultraviolet (UV) radiation, infrared rays and heat, and these stimuli are known to induce skin angiogenesis. Interestingly, although acute UV irradiation stimulates skin angiogenesis, cutaneous blood vessels are decreased in chronically photodamaged skin. The reason for the differential effects of acute and chronic UV exposure on skin angiogenesis remains to be elucidated. This review discusses the vascularization changes in intrinsically aged and photoaged human skin, the effects of UV irradiation, infrared rays and heat on skin angiogenesis, and the effects of topical retinoic acid treatment on UV-induced angiogenesis and cutaneous vascularity in aged and photoaged human skin. An understanding of the molecular mechanisms of aging- and photoaging-dependent changes of skin angiogenesis may provide us with new insights to prevent and treat the skin aging process.
Chung
Jin Ho
JH
Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea.
Eun
Hee Chul
HC
D003879:Dermatologic Agents / Q000494:pharmacology*; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D007259:Infrared Rays / Q000009:adverse effects; D045726:Metalloproteases / Q000378:metabolism; D009389:Neovascularization, Pathologic / Q000503:physiopathology*; D012867:Skin / Q000098:blood supply / Q000473:pathology* / Q000528:radiation effects; D015595:Skin Aging / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D014212:Tretinoin / Q000494:pharmacology*; D014466:Ultraviolet Rays / Q000009:adverse effects*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D003879:Dermatologic Agents; D042461:Vascular Endothelial Growth Factor A; D014212:Tretinoin; D045726:Metalloproteases