Interleukin-13 induction of 15-lipoxygenase gene expression requires p38 mitogen-activated protein kinase-mediated serine 727 phosphorylation of Stat1 and Stat3.
Interleukin-13 (IL-13) is a cytokine secreted by Th2 lymphocytes that is capable of inducing expression of 15-lipoxygenase (15-LO) in primary human monocytes. We recently demonstrated that induction of 15-LO requires the activation of Jak2 and Tyk2 kinases and Stats 1, 3, 5, and 6. Since IL-13-induced 15-LO expression was inhibited by H7 (a serine-threonine kinase inhibitor), we predicted that Stat serine phosphorylation may also be crucial for 15-LO expression. In this study, we present evidence indicating that IL-13-induced 15-LO mRNA expression was detectable as early as 1 h by real-time reverse transcription-PCR. We found that IL-13 induced a time-dependent serine phosphorylation of both Stat1 and Stat3, detectable at 15 min after IL-13 treatment. In addition, the activation of p38 mitogen-activated protein kinase (MAPK) was detected in a time-dependent fashion, with peak phosphorylation at 15 min after IL-13 treatment. SB202190, a p38 MAPK-specific inhibitor, markedly inhibited IL-13-induced Stat1 and Stat3 serine phosphorylation as well as DNA binding. Furthermore, treatment of cells with Stat1 or Stat3 decoys significantly impaired IL-13-induced 15-LO expression. Taken together, our results provide the first evidence that IL-13 induces p38 MAPK phosphorylation/activation, which regulates Stat1 and Stat3 serine 727 phosphorylation. Both of these events are important steps in IL-13-induced 15-LO expression in human monocytes.
Xu
Bo
B
Department of Cell Biology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Bhattacharjee
Ashish
A
Roy
Biswajit
B
Xu
Hong-Min
HM
Anthony
David
D
Frank
David A
DA
Feldman
Gerald M
GM
Cathcart
Martha K
MK
D000818:Animals; D001093:Arachidonate 15-Lipoxygenase / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D018793:Interleukin-13 / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009000:Monocytes / Q000166:cytology / Q000378:metabolism; D010766:Phosphorylation; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor; D012694:Serine / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases
D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D018793:Interleukin-13; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; D012694:Serine; D004247:DNA; D001093:Arachidonate 15-Lipoxygenase; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases