title: High-fat diet exacerbates inflammation and cell survival signals in the skin of ultraviolet B-irradiated C57BL/6 mice.
abstract: Inflammation induced by chronic exposure to ultraviolet (UV) radiation has been implicated in various skin diseases. We formulated the hypothesis that a high-fat diet may influence the UV-induced inflammatory responses in the skin. C57BL/6 mice were fed a high-fat diet or control diet and exposed to UVB radiation (120 mJ/cm(2)) three times/week for 10 weeks. The mice were then sacrificed and skin and plasma samples collected for analysis of biomarkers of inflammatory responses using immunohistochemistry, western blotting, ELISA and real-time PCR. We found that the levels of inflammatory biomarkers were increased in the UVB-exposed skin of the mice fed the high-fat diet than the UVB-exposed skin of the mice fed the control diet. The levels of inflammatory biomarkers of early responses to UVB exposure (e.g., myeloperoxidase, cyclooxygenase-2, prostaglandin-E(2)), proinflammatory cytokines (i.e., tumor necrosis factor-alpha, interleukin-1beta, interleukin-6), and proliferating cell nuclear antigen and cell survival signals (phosphatidylinositol-3-kinase and p-Akt-Ser(473)) were higher in high-fat-diet-fed mouse skin than control-diet-fed mouse skin. The plasma levels of insulin growth factor-1 were greater in the UVB-irradiated mice fed the high-fat diet than the UVB-irradiated mice fed the control diet, whereas the levels of plasma adiponectin were significantly lower. This pronounced exacerbation of the UVB-induced inflammatory responses in the skin of mice fed a high-fat diet suggests that high-fat diet may increase susceptibility to inflammation-associated skin diseases, including the risk of skin cancer.
authors.affiliation: Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
authors.forename: Syed M
authors.initials: SM
authors.lastname: Meeran
authors.forename: Tripti
authors.initials: T
authors.lastname: Singh
authors.forename: Tim R
authors.initials: TR
authors.lastname: Nagy
authors.forename: Santosh K
authors.initials: SK
authors.lastname: Katiyar
mesh_terms: D052242:Adiponectin / Q000097:blood; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015415:Biomarkers; D015153:Blotting, Western; D002470:Cell Survival / Q000187:drug effects* / Q000528:radiation effects*; D051546:Cyclooxygenase 2 / Q000096:biosynthesis; D004032:Diet; D004041:Dietary Fats / Q000633:toxicity*; D015232:Dinoprostone / Q000096:biosynthesis; D005260:Female; D007124:Immunoenzyme Techniques; D020287:In Situ Nick-End Labeling; D007249:Inflammation / Q000139:chemically induced / Q000473:pathology*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D020556:Neutrophil Infiltration / Q000187:drug effects; D051058:Oncogene Protein v-akt / Q000096:biosynthesis; D009195:Peroxidase / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000096:biosynthesis; D012867:Skin / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D014466:Ultraviolet Rays; D015430:Weight Gain / Q000187:drug effects
chemical_list: D052242:Adiponectin; D015415:Biomarkers; D004041:Dietary Fats; D007334:Insulin-Like Growth Factor I; D009195:Peroxidase; D051546:Cyclooxygenase 2; D019869:Phosphatidylinositol 3-Kinases; D051058:Oncogene Protein v-akt; D015232:Dinoprostone