title: Apoptotic cell death in rat lung following mustard gas inhalation.
abstract: To investigate apoptosis as a mechanism of sulfur mustard (SM) inhalation injury in animals, we studied different caspases (caspase-8, -9, -3, and -6) in the lungs from a ventilated rat SM aerosol inhalation model. SM activated all four caspases in cells obtained from bronchoalveolar lavage fluid (BALF) as early as 6 h after exposure. Caspase-8, which is known to initiate the extrinsic Fas-mediated pathway of apoptosis, was increased fivefold between 6 and 24 h, decreasing to the unexposed-control level at 48 h. The initiator, caspase-9, in the intrinsic mitochondrial pathway of apoptosis as well as the executioner caspases, caspase-3 and -6, all peaked (P< 0.01) at 24 h; caspase-3 and -6 remained elevated, but caspase-9 decreased to unexposed-control level at 48 h. To study further the Fas pathway, we examined soluble as well as membrane-bound Fas ligand (sFas-L and mFas-L, respectively) and Fas receptor (Fas-R) in both BALF cells and BALF. At 24 h after SM exposure, sFas-L increased significantly in both BALF cells (P< 0.01) and BALF (P< 0.05). However, mFas-L increased only in BALF cells between 24 and 48 h (P< 0.1 andP< 0.001, respectively). Fas-R increased only in BALF cells by 6 h (P< 0.01) after SM exposure. Apoptosis in SM-inhaled rat lung specimens was also confirmed by both immunohistochemical staining using cleaved caspase-3 and -9 antibodies and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining as early as 6 h in the proximal trachea and bronchi, but not before 48 h in distal airways. These findings suggest pathogenic mechanisms at the cellular and molecular levels and logical therapeutic target(s) for SM inhalation injury in animals.
authors.affiliation: Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Aberdeen, Maryland devon.k.andres.ctr@mail.mil.
authors.forename: Devon K
authors.initials: DK
authors.lastname: Andres
authors.affiliation: Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Aberdeen, Maryland.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Keyser
authors.affiliation: Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Aberdeen, Maryland.
authors.forename: Ashley A
authors.initials: AA
authors.lastname: Melber
authors.affiliation: Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Aberdeen, Maryland.
authors.forename: Betty J
authors.initials: BJ
authors.lastname: Benton
authors.affiliation: Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Aberdeen, Maryland.
authors.forename: Tracey A
authors.initials: TA
authors.lastname: Hamilton
authors.affiliation: Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Aberdeen, Maryland.
authors.forename: Denise M
authors.initials: DM
authors.lastname: Kniffin
authors.affiliation: Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Aberdeen, Maryland.
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Martens
authors.affiliation: Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Aberdeen, Maryland.
authors.forename: Radharaman
authors.initials: R
authors.lastname: Ray
mesh_terms: D000818:Animals; D017209:Apoptosis; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D020169:Caspases / Q000378:metabolism; D004789:Enzyme Activation; D053222:Fas Ligand Protein / Q000378:metabolism; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D019570:Inhalation Exposure; D008168:Lung / Q000201:enzymology / Q000473:pathology*; D008297:Male; D009151:Mustard Gas / Q000009:adverse effects*; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D012995:Solubility; D013997:Time Factors; D019014:fas Receptor / Q000378:metabolism
chemical_list: D053222:Fas Ligand Protein; D019014:fas Receptor; D020169:Caspases; D009151:Mustard Gas
keywords: Fas-mediated pathway; immunohistochemistry; inhalation injury; mustard gas; sulfur mustard