The Impact of Sunlight on Skin Aging
Purpose of Review
In this review, we summarize and discuss the current literature on photoaging. We focus on the molecular effects of UV radiation, and the histological and clinical features of chronically sun-exposed skin.
The expression of numerous proteins is altered in habitually sun-exposed skin, including sirtuins and hedgehog signaling proteins. Pharmacological manipulation of the levels of these proteins can potentially downregulate the photoaging process.
Mitochondrial and nuclear DNA damage, reactive oxygen species (ROS) production, and altered gene expression patterns are critical components of both photoaging and chronological aging. Chronic UVA and UVB exposure result in the photoaged phenotype through distinct molecular mechanisms, with UVA being primarily ROS-mediated and UVB being DNA damage-mediated. Molecular effects result in an altered dermal and epidermal environment that manifests as the photoaged phenotype. Importantly, skin phototype and environmental influences impact individual responses to chronic UV radiation.
KeywordsUltraviolet radiation Sunlight Carcinogenesis Geriatrics
Compliance with Ethical Guidelines
Conflict of Interest
Taylor Braunberger is a sub-investigator for Bayer, Estee Lauder, Unigen, and Ferndale. Amanda Nahhas is a sub-investigator for Bayer, Estee Lauder, Unigen, and Ferndale. Iltefat Hamzavi is an investigator for Incyte Corporation, Bayer, Estee Lauder, Unigen, and Ferndale. Henry Lim is a co-investigator for Allergen, Estee Lauder, Incyte, and Ferndale. Hisham Kaddurah and Gautham Vellaichamy state no conflicts of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
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