title: Differential role of hydrogen peroxide in UV-induced signal transduction.
abstract: The present study investigated the differential requirement of ROS in UV-induced activation of these pathways. Exposure of the mouse epidermal C141 cells to UV radiation led to generation of ROS as measured by electron spin resonance (ESR) and by H2O2 and O2. fluorescence staining assay. Treatment of cells with UV radiation or H2O2 also markedly activated Erks, JNKs, p38 kinase and led to increases in phosphorylation of Akt and p70(S6k) in mouse epidermal JB6 cells. The scavenging of UV-generated H2O2 by N-acety-L-cyteine (NAC, a general antioxidant) or catalase (a specific H2O2 inhibitor) inhibited UV-induced activation of JNKs, p38 kinase, Akt and p70(S6k), while it did not show any inhibitory effects on Erks activation. Further, pretreatment of cells with sodium formate (an .OH radical scavenger) or superoxide dismutase (O2-. radical scavenger) did not inhibit any of these pathways. These results demonstrate that H2O2 generation is required for UV-induced phosphorylation of Akt and p70(S6k), and involved in activation of JNKs and p38 kinase, but not Erks.
authors.affiliation: Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Ding
authors.forename: Jingxia
authors.initials: J
authors.lastname: Li
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Leonard
authors.forename: Xianglin
authors.initials: X
authors.lastname: Shi
authors.forename: Max
authors.initials: M
authors.lastname: Costa
authors.forename: Vincent
authors.initials: V
authors.lastname: Castranova
authors.forename: Val
authors.initials: V
authors.lastname: Vallyathan
authors.forename: Chuanshu
authors.initials: C
authors.lastname: Huang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D004578:Electron Spin Resonance Spectroscopy; D004789:Enzyme Activation / Q000187:drug effects / Q000528:radiation effects; D005419:Flavonoids / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects / Q000528:radiation effects; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D017382:Reactive Oxygen Species / Q000378:metabolism; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism; D015398:Signal Transduction / Q000528:radiation effects*; D013481:Superoxides / Q000378:metabolism; D014466:Ultraviolet Rays; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D005419:Flavonoids; D011518:Proto-Oncogene Proteins; D017382:Reactive Oxygen Species; D013481:Superoxides; D006861:Hydrogen Peroxide; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one