title: Involvement of reactive oxygen species in indomethacin-induced apoptosis of small intestinal epithelial cells.
abstract: BACKGROUND
  The precise pathogenic mechanism of nonsteroidal antiinflammatory drug-induced small intestinal injury is still unknown. In the present study, we investigated the mechanism by which indomethacin induced mucosal injury by using an in vitro model of small intestine.
  
  
  METHODS
  The colon cancer cell line Caco-2, exhibiting a small intestinal phenotype starting as a crypt cell and differentiating to a villous phenotype, and RIE, a rat intestinal epithelial cell line, were employed. Indomethacin was added to differentiated the Caco-2 and RIE monolayer, and cell death was quantified by MTT assay and LDH release in the cell culture supernatant. Indomethacin-induced cell death was also qualified by fluorescent probes under the fluorescent microscope. As a functional study, the permeability of the Caco-2 monolayer was assessed by measuring transepithelial electrical resistance (TEER) and the flux of FITC-conjugated dextran across the monolayer. Indomethacin-induced reactive oxygen species production in Caco-2 and RIE was evaluated by redoxsensitive fluorogenic probes using a fluorometer. In some experiments, antioxidants were used to clarify the role of reactive oxygen species on indomethacin-induced Caco-2 cell death.
  
  
  RESULTS
  Indomethacin caused cell death (mainly apoptosis) of Caco-2 and RIE in a dose-and time-dependent manner that was correlated with increased permeability of the Caco-2 monolayer. Exposure of Caco-2 and RIE with indomethacin also resulted in a significant reactive oxygen species production that was inhibited by the pretreatment of these cells with antioxidants.
  
  
  CONCLUSIONS
  Taken together, reactive oxygen species production is one of the mechanisms by which indomethacin induced small intestinal injury.
authors.affiliation: Department of Molecular Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, 465 Kajiicho, Kamigyo-ku, Kyoto, 602-8566, Japan.
authors.forename: Tatsushi
authors.initials: T
authors.lastname: Omatsu
authors.forename: Yuji
authors.initials: Y
authors.lastname: Naito
authors.forename: Osamu
authors.initials: O
authors.lastname: Handa
authors.forename: Natsuko
authors.initials: N
authors.lastname: Hayashi
authors.forename: Katsura
authors.initials: K
authors.lastname: Mizushima
authors.forename: Ying
authors.initials: Y
authors.lastname: Qin
authors.forename: Ikuhiro
authors.initials: I
authors.lastname: Hirata
authors.forename: Satoko
authors.initials: S
authors.lastname: Adachi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Okayama
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kishimoto
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Takagi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kokura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yoshikawa
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000633:toxicity*; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D018938:Caco-2 Cells; D002454:Cell Differentiation; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D017097:Electric Impedance; D005470:Fluorometry; D006801:Humans; D007213:Indomethacin / Q000008:administration & dosage / Q000633:toxicity*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism; D010539:Permeability / Q000187:drug effects; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D017382:Reactive Oxygen Species; D007213:Indomethacin