title: [Role of oxidative stress in endoplasmic reticulum stress? induced apoptosis of alveolar macrophages triggered by quartz dust].
abstract: OBJECTIVE
  To investigate the role of oxidative stress in the endoplasmic reticulum stress-induced apoptosis of alveolar macrophages triggered by quartz dust.
  
  
  METHODS
  Seventy-two healthy adult Wistar rats were randomly divided into control group, quartz dust group, quartz dust plus N-acetyl cysteine (NAC) group, and NAC group, with 18 rats in each group. One milliliter of sterile saline (for the control and NAC groups) or 1 ml of saline with 5%ultrafine quartz dust (for dust group and dust plus NAC group) was given to each rat by non-exposed endotracheal infusion. From the second day after dust infusion, rats in dust plus NAC group and NAC group received intragastric administration of NAC (100 mg/kg). In each week, the treatment with NAC lasted for 5 consecutive days, followed by 2 days' interval. For each group, 6 rats were randomly selected on the 14th, 28th, or 56th day after dust exposure; they were sacrificed by bloodletting from the femoral artery, and the lungs were collected. Bronchoalveolar lavage fluid was collected to separate macrophages. The protein expression of caspase-12 in alveolar macrophages, the apoptosis rate and reactive oxygen species (ROS) content of alveolar macrophages, and the protein carbonyl content of alveolar macrophages were determined by Western blot, flow cytometry, and colorimetry, respectively.
  
  
  RESULTS
  Increased protein expression of caspase-12, apoptosis rate, and content of ROS and protein carbonyl were discovered on the 14th day in the dust group, in comparison with the control group (P < 0.05), and the increase lasted till the 28th and 56th days. (P < 0.05). Compared with the dust group, the dust plus NAC group showed significant decreases in the content of ROS on the 14th, 28th, and 56th days (P < 0.05), significant decreases in the content of protein carbonyl on the 28th and 56th days (P < 0.05), and significant decreases in the protein expression of caspase-12 and apoptosis rate (P < 0.05).
  
  
  CONCLUSIONS
  Oxidative stress is potentially involved in the endoplasmic reticulum stress-induced apoptosis of alveolar macrophages triggered by quartz dust. Oxidative damage of protein in the endoplasmic reticulum may play an important role in the process.
authors.affiliation: Department of Occupational Health, School of Public Health, Shanxi Medical University , Taiyuan 030001, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Occupational Health, School of Public Health, Shanxi Medical University , Taiyuan 030001, China.
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Occupational Health, School of Public Health, Shanxi Medical University , Taiyuan 030001, China.
authors.forename: Qiuying
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Occupational Health, School of Public Health, Shanxi Medical University , Taiyuan 030001, China.
authors.forename: Chengyun
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Occupational Health, School of Public Health, Shanxi Medical University , Taiyuan 030001, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D053454:Caspase 12 / Q000378:metabolism; D004391:Dust; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D016676:Macrophages, Alveolar / Q000187:drug effects / Q000473:pathology*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D050050:Protein Carbonylation; D011791:Quartz / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D004391:Dust; D017382:Reactive Oxygen Species; D011791:Quartz; C506443:Casp12 protein, rat; D053454:Caspase 12