Role of cell/cell interactions in silica-induced production of inflammatory mediators in the lung.
FASEB J 2004 Mar; 18(5)(Suppl):A1139-A1140
Exposure of rat alveolar macrophages (AM) to silica in vitro upregulates mRNA expression of a limited number inflammatory mediators compared mRNA upregulation in AM isolated after in vivo exposure to silica (Rao et al., FASEB J. 17:C294, 2003). This observation suggested that cell/cell interactions may play a role in upregulating mRNA expression of some inflammatory mediators. In order to study cell/cell interactions, we isolated AM, rat alveolar type II cells (type II) and lung fibroblasts (LF). mRNA expression of five genes (IL-1(, IL-6, IL-10, iNOS and GM-CSF) was measured by real-time RT/PCR following co-culture of AM with previously cultured type II cells or LF, with or without 200 (g/ml of silica (Min-U-Sil 5). Silica had no additional effects on the expression of any of the cytokines. Therefore, only the data with co-cultures alone, without silica exposure, are shown below: Type II LF AM* Type II* + AM* LF* +AM* IL-1( 1.21 ( 0.07 0.03 ( 0.01 1.1 ( 0.06 N.D. 2.2 ( 1 IL-6 1.27 ( 0.15 0.06 ( 0.26 3.9 ( 3.16 36 ( 26 1730 ( 531 IL-10 1.21 ( 0.11 1.8 ( 0.5 1.4 ( 1.46 0.2 ( 0.3 27 ( 9 iNOS 1.36 ( 0.11 0.15 ( 0.02 1.7 ( 1.63 0.7 ( 0.4 11.5 ( 4 GM-CSF 1.33 ( 0.18 0.06 ( 0.18 3.5 ( 0.71 23 ( 11 40 ( 17 *The numbers in these columns represent mRNA expression (mean ( SEM of at least 3 separate experiments) relative to AM alone (column 2). N.D. not detectable. These data indicate that LF are an important source of inflammatory mediators and that AM/LF interactions play a role in the expression of IL-6, IL-10 and iNOS in basal co-cultures.
In-vitro-studies; In-vitro-study; Cell-alteration; Cell-biology; Cell-culture-techniques; Cell-function; Cell-metabolism; Cellular-function; Cellular-transport-mechanism; Lung; Lung-cells; Pulmonary-system-disorders; Pulmonary-function-tests; Pulmonary-function; Dust-analysis; Silica-dusts
NIOSH, PPRB, HELD, Morgantown, WV 26505
Abstract; Conference/Symposia Proceedings
The FASEB Journal. Experimental Biology 2004, Washington, DC, April 17-21, 2004