Tumor necrosis factor-alpha-induced cyclooxygenase-2 expression in human tracheal smooth muscle cells: involvement of p42/p44 and p38 mitogen-activated protein kinases and nuclear factor-kappaB.
This study was to determine the mechanism of tumor necrosis factor-alpha (TNF-alpha)-enhanced cyclooxygenase (COX)-2 expression associated with prostaglandin E2 (PGE2) synthesis in human tracheal smooth muscle cells (HTSMCs). TNF-alpha markedly increased COX-2 expression and PGE2 synthesis in a time- and concentration-dependent manner, whereas COX-1 remained unaltered. Tyrosine kinase inhibitor (genistein), phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor (D-609) and PKC inhibitor (GF109203X) attenuated TNF-alpha-induced COX-2 expression and PGE2 synthesis in HTSMCs. TNF-alpha-induced COX-2 expression and PGE2 synthesis were also inhibited by PD98059 (an inhibitor of MEK1/2) and SB203580 and SB202190 (inhibitors of p38 MAPK), respectively, suggesting the involvement of p42/p44 and p38 MAPKs in these responses. This hypothesis was further supported by that TNF-alpha induced a transient activation of p42/p44 and p38 MAPKs in a time-and concentration-dependent manner. Furthermore, TNF-alpha-induced activation of nuclear factor-kappaB (NF-kappaB) reversely correlated with the degradation of IkappaB-alpha in HTSMCs. TNF-alpha-induced COX-2 expression and PGE2 synthesis was also inhibited by NF-kappaB inhibitor pyrrolidinedithiocarbamate (PDTC). These findings suggest that the increased expression of COX-2 correlates with the release of PGE2 from TNF-alpha-challenged HTSMCs, at least in part, mediated through p42/p44 and p38 MAPKs as well as NF-kappaB signaling pathways in HTSMCs.
Lin
Chih-Chung
CC
Department of Anesthetics, College of Medicine, Chang Gung University Kwei-San, Tao-Yuan, Taiwan.
Hsiao
Li-Der
LD
Chien
Chin-Sung
CS
Lee
Chiang-Wen
CW
Hsieh
Jen-Tsung
JT
Yang
Chuen-Mao
CM
D002478:Cells, Cultured; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000096:biosynthesis; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis* / Q000378:metabolism; D008565:Membrane Proteins; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000201:enzymology*; D016328:NF-kappa B / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014132:Trachea / Q000166:cytology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases
D004791:Enzyme Inhibitors; D007527:Isoenzymes; D008565:Membrane Proteins; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D015232:Dinoprostone