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Multifaceted pathways protect human skin from UV radiation


The recurrent interaction of skin with sunlight is an intrinsic constituent of human life, and exhibits both beneficial and detrimental effects. The apparent robust architectural framework of skin conceals remarkable mechanisms that operate at the interface between the surface and environment. In this Review, we discuss three distinct protective mechanisms and response pathways that safeguard skin from deleterious effects of ultraviolet (UV) radiation. The unique stratified epithelial architecture of human skin along with the antioxidant-response pathways constitutes the important defense mechanisms against UV radiation. The intricate pigmentary system and its intersection with the immune-system cytokine axis delicately balance tissue homeostasis. We discuss the relationship among these networks in the context of an unusual depigmenting disorder, vitiligo. The elaborate tunable mechanisms, elegant multilayered architecture and evolutionary selection pressures involved in skin and sunlight interaction makes this a compelling model to understand biological complexity.

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Figure 1: Architecture of epidermal cell layers of human skin.
Figure 2: Schematic of skin lipids and their associated pathway in epidermal layers.
Figure 3: Photodamage and stress response in the skin.
Figure 4: Kinetics of pigmentation response and pathways activated in the epidermis upon exposure to UV light.
Figure 5: Temporal regulation of skin pigmentation by IFN-γ: scheme of events in melanocytes and keratinocytes as a part of a delayed tanning response and recovery.
Figure 6: Photograph of an individual with vitiligo.


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This work was supported by grant (TOUCH-BSC0302). P.G., A.R. and R.G. are supported by the Council for Scientific and Industrial Research (CSIR), India. We acknowledge CSIR and Department of Biotechnology for institutional support to CSIR-Institute of Genomics and Integrative Biology and National Institute of Immunology, respectively.

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Correspondence to Rajesh S Gokhale.

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R.S.G. is the co-founder director on the board of Vyome Biosciences, a biopharmaceutical company in the area of dermatology.

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Natarajan, V., Ganju, P., Ramkumar, A. et al. Multifaceted pathways protect human skin from UV radiation. Nat Chem Biol 10, 542–551 (2014).

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