title: Reactive oxygen species in HaCaT keratinocytes after UVB irradiation are triggered by intracellular Ca(2+) levels.
abstract: It is recognized that reactive oxygen species (ROS) are responsible for skin damage due to UVB-radiation (UVB-R). However, the triggering substance(s) for ROS generation after UVB-R is uncertain with respect to the activation of NADPH oxidase (Nox), xanthine oxidase (XOD), and respiratory chain-chain reactions in mitochondria. As a first step in identifying the trigger(s) for UVB-induced ROS generation, we examined the relationship between Ca(2+) levels and ROS generation in HaCaT keratinocytes. UVB-R exposure of HaCaT keratinocytes resulted in an immediate elevation of ROS that recurred 7 hours later. This was accompanied by immediately elevated intracellular Ca(2+) . A Ca(2+) chelating agent, BAPTA, abolished the elevation of ROS after UVB-R completely. In addition, exogenous H(2)O(2) did not increase intracellular Ca(2+) levels. This suggests that intracellular Ca(2+) is the first trigger for UVB-induced ROS generation.Journal of Investigative Dermatology Symposium Proceedings (2009) 14, 50-52; doi:10.1038/jidsymp.2009.12.
authors.affiliation: Cosmos Technical Center Co., LTD., 3-24-3 Hasune, Itabashi-Ku, Tokyo, Japan. masaki@ns-cosmos.co.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Masaki
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Izutsu
authors.forename: Shoichi
authors.initials: S
authors.lastname: Yahagi
authors.forename: Yuri
authors.initials: Y
authors.lastname: Okano
mesh_terms: D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects / Q000528:radiation effects; D002460:Cell Line; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects*; D017382:Reactive Oxygen Species / Q000378:metabolism* / Q000633:toxicity; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D002614:Chelating Agents; D017382:Reactive Oxygen Species; D004533:Egtazic Acid; D006861:Hydrogen Peroxide; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium