title: [The role of heme oxygenase 1 in hydrogen peroxide induced apoptosis and mitochondrial trans membrane potential change in rat primary type II alveolar epithelium cells].
abstract: OBJECTIVE
  To understand the role of heme oxygenase-1 (HO-1) in hydrogen peroxide [H(2)O(2)] induced apoptosis and mitochondrial trans-membrane potential (MTMP) change in primary alveolar epithelial cell type II(AEC II).
  
  
  METHODS
  Primary AEC II collected from healthy Sprague Dawley (SD) rats were cultured for 24 hours, then divided into four groups to be treated with: (1) saline; (2) H(2)O(2)  (0.5 mmol/L); (3) H(2)O(2) +HO-1 (0.2 mmol/L); (4) H(2)O(2)  +zinc original porphyrin IX (HO-1 inhibitor, 20 μmol/L). The morphology of cells in the cultures was examined by fluorescent microscopy 2.5 hours later, and the number of apoptotic cells / the MTMP determined by flow-cytometry 0.5, 1.0, 1.5, 2.0 and 2.5 hours later.
  
  
  RESULTS
  Large number of cells in with green (early apoptotic) or red (later apoptotic) fluorescence were observed by microscope in cultures treated with H(2)O(2) , and H(2)O(2) + HO-1 inhibitor, but such cells were obviously fewer in HO-1 treated cultures. Compared with saline treated cells, H(2)O(2)  treated cells had significantly higher apoptosis rate, that increased with time, reaching peak value 2.5 hours into the treatment [0.5 hour: (30.27 ± 0.74)% vs. (3.76 ± 0.81)%, 2.5 hours: (40.46 ± 0.91)% vs. (22.74 ± 0.60)%, both P < 0.05], while the rate of MTMP depolarization was significantly lower (0.99 ± 0.21 vs. 1.91 ± 0.16, P < 0.05) in these cells. Compared with H(2)O(2)  treated cells, the apoptosis rate in HO-1 treated cells was significantly lower [0.5 hour: (5.99 ± 0.60)% vs. (30.27 ± 0.74)%, 2.5 hours: (22.69 ± 1.69)% vs. (40.46 ± 0.91)%, both P < 0.05], and their rate of MTMP depolarization higher (2.02 ± 0.12 vs. 0.99 ± 0.21, P < 0.05). Compared with HO-1 treated cells, HO-1 inhibitor treated cells had significantly higher apoptosis rate which reached peak value 2.5 hours into the treatment [0.5 hour: (30.73 ± 1.08)% vs. (5.99 ± 0.60)%, 2.5 hours: (41.38 ± 0.57)% vs. (22.69 ± 1.69)%, both P < 0.05], while rate of MTMP depolarization in these cells was significantly lower (0.98 ± 0.09 vs. 2.02 ± 0.12, P < 0.05).
  
  
  CONCLUSIONS
  HO-1 could maintain the integrity of AEC II and stabilize their mitochondria membrane potential, protecting the cells from H(2)O(2)  induced damage.
authors.affiliation: Zunyi Medical College, Zunyi 563000, Guizhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wu
authors.forename: Miao
authors.initials: M
authors.lastname: Chen
authors.forename: Shuang
authors.initials: S
authors.lastname: Wu
authors.forename: Hong-min
authors.initials: HM
authors.lastname: Wang
authors.forename: Ming-jiang
authors.initials: MJ
authors.lastname: Qian
authors.forename: Yu-hui
authors.initials: YH
authors.lastname: Wang
authors.forename: Xiao-yun
authors.initials: XY
authors.lastname: Fu
mesh_terms: D056809:Alveolar Epithelial Cells / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D051547:Heme Oxygenase-1 / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D006861:Hydrogen Peroxide; D051547:Heme Oxygenase-1