Cigarette smoke extract regulates cytosolic phospholipase A2 expression via NADPH oxidase/MAPKs/AP-1 and p300 in human tracheal smooth muscle cells.
Up-regulation of cytosolic phospholipase A(2) (cPLA(2)) by cigarette smoke extract (CSE) may play a critical role in airway inflammatory diseases. However, the mechanisms underlying CSE-induced cPLA(2) expression in human tracheal smooth muscle cells (HTSMCs) were not completely understood. Here, we demonstrated that CSE-induced cPLA(2) protein and mRNA expression was inhibited by pretreatment with the inhibitors of AP-1 (tanshinone IIA) and p300 (garcinol) or transfection with siRNAs of c-Jun, c-Fos, and p300. Moreover, CSE also induced c-Jun and c-Fos expression, which were inhibited by pretreatment with the inhibitors of NADPH oxidase (diphenyleneiodonium chloride and apocynin) and the ROS scavenger (N-acetyl-L-cysteine) or transfection with siRNAs of p47(phox) and NADPH oxidase (NOX)2. CSE-induced c-Fos expression was inhibited by pretreatment with the inhibitors of MEK1 (U0126) and p38 MAPK (SB202190) or transfection with siRNAs of p42 and p38. CSE-induced c-Jun expression and phosphorylation were inhibited by pretreatment with the inhibitor of JNK1/2 (SP600125) or transfection with JNK2 siRNA. CSE-stimulated p300 phosphorylation was inhibited by pretreatment with the inhibitors of NADPH oxidase and JNK1/2. Furthermore, CSE-induced p300 and c-Jun complex formation was inhibited by pretreatment with diphenyleneiodonium chloride, apocynin, N-acetyl-L-cysteine or SP600125. These results demonstrated that CSE-induced cPLA(2) expression was mediated through NOX2-dependent p42/p44 MAPK and p38 MAPK/c-Fos and JNK1/2/c-Jun/p300 pathways in HTSMCs.
Department of Physiology and Pharmacology, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan.
Shin-Ei
SE
Cheng
Chih-Chung
CC
Lin
I-Ta
IT
Lee
Chih-Kai
CK
Hsu
Yu Ru
YR
Kou
Chuen-Mao
CM
Yang
D015153:Blotting, Western; D002460:Cell Line; D050881:E1A-Associated p300 Protein / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D019255:NADPH Oxidases / Q000378:metabolism*; D054510:Phospholipases A2, Cytosolic / Q000378:metabolism*; D034741:RNA, Small Interfering; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012907:Smoking / Q000009:adverse effects*; D014132:Trachea / Q000166:cytology*; D018808:Transcription Factor AP-1 / Q000378:metabolism*
D034741:RNA, Small Interfering; D018808:Transcription Factor AP-1; D019255:NADPH Oxidases; D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human; D020928:Mitogen-Activated Protein Kinases; D054510:Phospholipases A2, Cytosolic