Local increase in interleukin-1-like activity following UVB irradiation of human skin in vivo.
ABSTRACT Using an in vivo skin chamber method, we demonstrated increased release of interleukin-1 (IL-1)-like activity at the site of irradiation with 3 times the minimal erythema dose of ultraviolet B (UVB). IL-1-like activity was estimated using the mouse thymocyte amplification assay. UVB-augmented release of IL-1-like activity peaked 1 h after irradiation and levels returned to baseline by 2 h. Release of IL-1-like activity from human skin after exposure to UV radiation may account for some of the local and systemic features of the sunburn response.
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ABSTRACT: Exposure to ultraviolet B (UVB) radiation from the sun can result in sunburn, premature aging and carcinogenesis, but the mechanism responsible for acute inflammation of the skin is not well understood. Here we show that RNA is released from keratinocytes after UVB exposure and that this stimulates production of the inflammatory cytokines tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) from nonirradiated keratinocytes and peripheral blood mononuclear cells (PBMCs). Whole-transcriptome sequencing revealed that UVB irradiation of keratinocytes induced alterations in the double-stranded domains of some noncoding RNAs. We found that this UVB-damaged RNA was sufficient to induce cytokine production from nonirradiated cells, as UVB irradiation of a purified noncoding RNA (U1 RNA) reproduced the same response as the one we observed to UVB-damaged keratinocytes. The responses to both UVB-damaged self-RNAs and UVB-damaged keratinocytes were dependent on Toll-like receptor 3 (TLR3) and Toll-like receptor adaptor molecule 1 (TRIF). In response to UVB exposure, Tlr3(-/-) mice did not upregulate TNF-α in the skin. Moreover, TLR3 was also necessary for UVB-radiation-induced immune suppression. These findings establish that UVB damage is detected by TLR3 and that self-RNA is a damage-associated molecular pattern that serves as an endogenous signal of solar injury.Nature medicine 07/2012; · 27.14 Impact Factor
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ABSTRACT: Sebaceous gland hyperplasia and increased sebum secretion after irradiation of ultraviolet (UV)-B has been widely accepted. This study was performed to clarify expression of inflammatory cytokines after irradiating UV-B in cultured sebocytes. Reverse transcription polymerase chain reaction was performed to measure gene expression of inflammatory cytokines, including interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor-α, in cultured sebocytes after exposure to 40 and 70 mJ/cm(2) UV-B. Protein expression of inflammatory cytokines and lipid production in cultured sebocytes after exposure to UV-B were measured using enzyme-linked immunoassay and lipid analysis kit. The expression of inflammatory cytokines, especially IL-1β and IL-8, was significantly increased in cultured sebocytes after treatment with UV-B. Many more studies on the effect of UV-B on sebaceous glands should be performed to reveal the pathogenic mechanism of acne.The Journal of Dermatology 12/2013; · 1.77 Impact Factor
Article: Solar radiation and human health[Show abstract] [Hide abstract]
ABSTRACT: The Sun has played a major role in the development of life on Earth. In Western culture, people are warned against Sun exposure because of its adverse effects: erythema, photoimmunosuppression, photoageing, photocarcinogenesis, cataracts and photokeratitis. However, Sun exposure is also beneficial, since moderate doses give beneficial physiological effects: vitamin D synthesis, reduction of blood pressure and mental health. Shortage of Sun exposure may be even more dangerous to human health than excessive exposure. Avoiding Sun exposure leads to vitamin D deficiency which is associated not only with rickets and osteomalacia, but also with increased risk of cardiovascular disease, multiple sclerosis, rheumatoid arthritis, diabetes, influenza, many types of cancer and adverse pregnancy outcomes. Solar radiation induces nitric oxide release in tissue and immediate pigment darkening which certainly play important roles, although these are still unknown. Action spectra relevant for health are described. We will also review what is known about spectral and intensity variations of terrestrial solar radiation as well as its penetration through the atmosphere and into human skin and tissue.Reports on Progress in Physics 05/2011; 74(6):066701. · 13.23 Impact Factor