Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ultraviolet radiation exposure damages DNA and promotes the development of skin cancer. In addition, UV exposure suppresses the immune response. Although the mechanism by which epidermal exposure to UV induces systemic immune suppression is not fully understood, it is clear that cytokines are involved. Therefore, quantitative measurement of cytokines is a critical aspect of modern research techniques. Determining the level of synthesis and secretion of cytokines in vivo or in vitro can be achieved through several possible techniques, depending on the sampling size, its physical state, and the type of answers required to test the hypothesis. When studying transcriptional activation, the level of cytokine mRNA is often determined using reverse transcription polymerase chain reaction (RT-PCR), ribonuclease protection assay (RPA), or Northern blot. Quantitative determinations of specific protein levels require a capture ELISA. As with any analytical technique, there are compromises among expense of sensitivity, labor, and time. These methods are discussed as they pertain to surveying cytokine induction and their relative usefulness to the laboratory scientist.
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PMID:Determining the role of cytokines in UV-induced immunomodulation. 1223 Nov 90

The main cause of skin cancer and photo-aging is chronic exposure to ultraviolet B (UVB) radiation. Such damage can be ameliorated by retinoid treatment. UVB-radiation-induced skin carcinogenesis is associated with the induction of activator protein 1 (AP1) signaling and factors, namely FOS and JUN family members. We investigated the effects of several retinoids, all-trans-retinoic acid (tRA), 9-cis-retinoic acid (cRA), and N-(4-hydroxyphenyl)-retinamide (HPR), on UVB-induced damage in primary mouse keratinocytes. In addition, the interplay between UVB radiation, retinoid receptors, and AP1 signaling was assessed using Western blot analysis and ribonuclease protection and gene reporter assays. Exposure of keratinocytes to UVB radiation caused a down-regulation of the retinoid receptor protein levels in a proteasome-mediated manner. In contrast, FOS and JUN proteins were transiently induced shortly after exposure to UVB radiation. Retinoid treatment caused a dose-dependent reduction in the levels of retinoid receptor proteins. When irradiated cells were treated with retinoids, no significant effects on AP1 protein expression were noted. Interestingly, pretreatments with tRA and cRA, but not HPR, suppressed UVB-radiation-induced AP1 activity by more than 50%, whereas post-treatment failed to produce similar effects. Our findings indicate that the inhibition of AP1 activity by retinoids explains, at least in part, the chemopreventive potential of retinoids in UV-radiation-associated epidermal damage.
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PMID:Regulation of ultraviolet B radiation-mediated activation of AP1 signaling by retinoids in primary keratinocytes. 1573 37