title: Thrombin induces inducible nitric oxide synthase expression via the MAPK, MSK1, and NF-κB signaling pathways in alveolar macrophages.
abstract: In this study, we investigated the roles of mitogen activated protein kinase (MAPK), mitogen stress-activated protein kinase 1 (MSK1), and nuclear factor-κB (NF-κB) signaling pathways in thrombin-induced inducible nitric oxide synthase (iNOS) expression in alveolar macrophages (NR8383). Treatment of NR8383 cells with thrombin caused an increase in iNOS expression in a concentration- and time-dependent manner. Treatment of NR8383 cells with SB203580 (4-(4-Fluorophenyl)-2-[4-(methylsulfinyl)phenyl]-5-(4-pyridyl)-1H-imidazole, a p38 MAPK inhibitor), PD98059 (2'-amino-3'-methoxyflavone, a MAPK kinase (MEK) inhibitor), and SP600125 (anthra[1-9-cd]pyrazol-6(2H)-one, a JNK inhibitor) all inhibited thrombin-induced iNOS expression. Stimulation of cells with thrombin caused an increase in p38 MAPK, ERK, and JNK phosphorylation. Treatment of cells with Ro 31-8220 (an MSK1 inhibitor) and MSK1 small interfering RNA (MSK1 siRNA) both inhibited thrombin-induced iNOS expression. Thrombin caused time-dependent activation of MSK1 Ser531 phosphorylation, which was inhibited by SB203580 and PD98059, but not by SP600125. Treatment of cells with pyrrolidine dithiocarbamate (PDTC, an NF-κB inhibitor) inhibited thrombin-induced iNOS expression in a concentration-dependent manner. Treatment of NR8383 cells with thrombin induced κB-luciferase activity and p65 Ser276 phosphorylation. Thrombin-induced increases in p65 Ser276 phosphorylation and κB-luciferase activity were inhibited by SB203580, PD98059, Ro 31-8220, and MSK1 siRNA. Taken together, these results suggest that the signaling pathways of MAPK, MSK1, and NF-κB play important roles in thrombin-induced iNOS expression in alveolar macrophages.
authors: Department of Chest Medicine, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.
authors: Chen-Chun
authors: CC
authors: Lin
authors: Chung-Huang
authors: CH
authors: Shih
authors: You-Lan
authors: YL
authors: Yang
authors: Mauo-Ying
authors: MY
authors: Bien
authors: Chien-Huang
authors: CH
authors: Lin
authors: Ming-Chih
authors: MC
authors: Yu
authors: Munisamy
authors: M
authors: Sureshbabu
authors: Bing-Chang
authors: BC
authors: Chen
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D016676:Macrophages, Alveolar / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D013917:Thrombin / Q000494:pharmacology*; D051996:Transcription Factor RelA / Q000737:chemistry / Q000378:metabolism*
chemical_list: D051996:Transcription Factor RelA; D012694:Serine; D052247:Nitric Oxide Synthase Type II; D038744:Ribosomal Protein S6 Kinases, 90-kDa; C116919:mitogen and stress-activated protein kinase 1; D020928:Mitogen-Activated Protein Kinases; D013917:Thrombin