title: Thrombin induces ICAM-1 expression in human lung epithelial cells via c-Src/PDGFR/PI3K/Akt-dependent NF-κB/p300 activation.
abstract: Up-regulation of ICAM-1 (intercellular adhesion molecule-1) is frequently implicated in lung inflammation and lung diseases, such as IPF (idiopathic pulmonary fibrosis). Thrombin has been shown to play a key role in inflammation via the induction of adhesion molecules, which then causes lung injury. However, the mechanisms underlying thrombin-induced ICAM-1 expression in HPAEpiCs (human pulmonary alveolar epithelial cells) remain unclear. In the present study, we have shown that thrombin induced ICAM-1 expression in HPAEpiCs. Pre-treatment with the inhibitor of thrombin [PPACK (D-Phe-Pro-Arg-chloromethyl ketone)], c-Src (PP1), PDGFR (platelet-derived growth factor receptor) (AG1296), PI3K (phosohinositide 3-kinase) (LY294002), NF-κB (nuclear factor κB) (Bay11-7082) or p300 (GR343) and transfection with siRNAs of c-Src, PDGFR, Akt, p65 and p300 markedly reduced thrombin-induced ICAM-1 expression and monocyte adherence to HPAEpiCs challenged with thrombin. In addition, we established that thrombin stimulated the phosphorylation of c-Src, PDGFR, Akt and p65, which were inhibited by pre-treatment with their respective inhibitors PP1, AG1296, LY294002 or Bay11-7082. In addition, thrombin also enhanced Akt and NF-κB translocation from the cytosol to the nucleus, which was reduced by PP1, AG1296 or LY294002. Thrombin induced NF-κB promoter activity and the formation of the p65-Akt-p300 complex, which were inhibited by AG1296, LY294002 or PP1. Finally, we have shown that thrombin stimulated in vivo binding of p300, Akt and p65 to the ICAM-1 promoter, which was reduced by AG1296, LY294002, SH-5 or PP1. These results show that thrombin induced ICAM-1 expression and monocyte adherence via a c-Src/PDGFR/PI3K/Akt/NF-κB-dependent pathway in HPAEpiCs. Increased understanding of the signalling mechanisms underlying ICAM-1 gene regulation will create opportunities for the development of anti-inflammatory therapeutic strategies.
authors: *Department of Anesthetics, Chang Gung Memorial Hospital at Lin-Kou and College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan.
authors: Shin-Ei
authors: SE
authors: Cheng
authors: †Department of Physiology and Pharmacology and Health Ageing Research Center, College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan.
authors: I-Ta
authors: IT
authors: Lee
authors: *Department of Anesthetics, Chang Gung Memorial Hospital at Lin-Kou and College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan.
authors: Chih-Chung
authors: CC
authors: Lin
authors: †Department of Physiology and Pharmacology and Health Ageing Research Center, College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan.
authors: Li-Der
authors: LD
authors: Hsiao
authors: †Department of Physiology and Pharmacology and Health Ageing Research Center, College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan.
authors: Chuen-Mao
authors: CM
authors: Yang
mesh_terms: D002460:Cell Line; D050881:E1A-Associated p300 Protein / Q000378:metabolism*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006490:Hemostatics / Q000494:pharmacology*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor / Q000378:metabolism; D013917:Thrombin / Q000494:pharmacology*
chemical_list: D006490:Hemostatics; D016328:NF-kappa B; D018799:Intercellular Adhesion Molecule-1; D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human; D019869:Phosphatidylinositol 3-Kinases; D017479:Receptors, Platelet-Derived Growth Factor; D016392:Proto-Oncogene Proteins pp60(c-src); D051057:Proto-Oncogene Proteins c-akt; D013917:Thrombin