Airborne agricultural particulate matter induces inflammatory cytokine secretion by respiratory epithelial cells: mechanisms of regulation by eicosanoid lipid signal mediators.
Malireddy-S; Lawson-C; Steinhour-E; Hart-J; Kotha-SR; Patel-RB; Zhao-L; Wilkins-JR; Marsh-CB; Magalang-UJ; Romberger-D; Wewers-MD; Parinandi-NL
Indian J Biochem Biophys 2013 Oct; 50(5):387-401
The purpose of this study was to elucidate the mechanism of the airborne poultry dust (particulate matter, PM)-induced respiratory tract inflammation, a common symptom in agricultural respiratory diseases. The study was based on the hypothesis that poultry PM would induce the release of inflammatory cytokine interleukin-8 (IL-8) by respiratory epithelial cells under the upstream regulation by cytosolic phospholipase A2 (cPLA2) activation and subsequent formation of cyclooxygenase (COX)- and lipoxygenase (LOX)-catalyzed arachidonic acid (AA) metabolites (eicosanoids). Human lung epithelial cells (A549) in culture were treated with the poultry PM (0.1-1.0 mg) for different lengths of time, following which PLA2 activity, release of eicosanoids and secretion of IL-8 in cells were determined. Poultry PM (1.0 mg/ml) caused a significant activation of PLA2 in a time-dependent manner (15-60 min), which was significantly attenuated by the calcium-chelating agents, cPLA2-specific inhibitor (AACOCF3) and antioxidant (vitamin C) in A549 cells. Poultry PM also significantly induced the release of COX- and LOX-catalyzed eicosanoids (prostaglandins, thromboxane A2 and leukotrienes B4 and C4) and upstream activation of AA LOX in the cells. Poultry PM also significantly induced release of IL-8 by the cells in a dose- and time-dependent manner, which was significantly attenuated by the calcium chelating agents, antioxidants and COX- and LOX-specific inhibitors. The current study for the first time revealed that the poultry PM-induced IL-8 release from the respiratory epithelial cells was regulated upstream by reactive oxygen species, cPLA2-, COX- and LOX-derived eicosanoid lipid signal mediators.
Agriculture; Agricultural-industry; Agricultural-workers; Animal-husbandry-workers; Poultry; Poultry-industry; Poultry-workers; Organic-dusts; Airborne-dusts; Airborne-particles; Particulate-dust; Farmers; Respiratory-system-disorders; Pulmonary-system-disorders; Lung-disorders; Lung-cells; Phospholipids; Prostaglandin-inhibitors; Leukocytes; Lipases; Laboratory-testing; Cell-cultures; Chelating-agents; Antioxidants; Lipids; Oxidative-processes;
Author Keywords: Organic poultry dust; Phospholipase A2; Interleukin-8; Lung epithelial cell; Prostaglandins; Leukotrienes; Occupational farm respiratory diseases
Narasimham L Parinandi, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University, College of Medicine, Columbus, OH 43210 USA
Agriculture, Forestry and Fishing
Indian Journal of Biochemistry and Biophysics
University of Nebraska