title: Quiescent and proliferative fibroblasts exhibit differential p300 HAT activation through control of 5-methoxytryptophan production.
abstract: Quiescent fibroblasts possess unique genetic program and exhibit high metabolic activity distinct from proliferative fibroblasts. In response to inflammatory stimulation, quiescent fibroblasts are more active in expressing cyclooxygenase-2 and other proinflammatory genes than proliferative fibroblasts. The underlying transcriptional mechanism is unclear. Here we show that phorbol 12-myristate 13-acetate (PMA) and cytokines increased p300 histone acetyltransferase activity to a higher magnitude (> 2 fold) in quiescent fibroblasts than in proliferative fibroblasts. Binding of p300 to cyclooxygenase-2 promoter was reduced in proliferative fibroblasts. By ultrahigh-performance liquid chromatography coupled with a quadrupole time of flight mass spectrometer and enzyme-immunoassay, we found that production of 5-methoxytryptophan was 2-3 folds higher in proliferative fibroblasts than that in quiescent fibroblasts. Addition of 5-methoxytryptophan and its metabolic precursor, 5-hydroxytryptophan, to quiescent fibroblasts suppressed PMA-induced p300 histone acetyltransferase activity and cyclooxygenase-2 expression to the level of proliferative fibroblasts. Silencing of tryptophan hydroxylase-1 or hydroxyindole O-methyltransferase in proliferative fibroblasts with siRNA resulted in elevation of PMA-induced p300 histone acetyltransferase activity to the level of that in quiescent fibroblasts, which was rescued by addition of 5-hydroxytryptophan or 5-methoxytryptophan. Our findings indicate that robust inflammatory gene expression in quiescent fibroblasts vs. proliferative fibroblasts is attributed to uncontrolled p300 histone acetyltransferase activation due to deficiency of 5-methoxytryptophan production. 5-methoxytryptophan thus is a potential valuable lead compound for new anti-inflammatory drug development.
authors: Metabolomic Medicine Research Center, China Medical University, Taichung, Taiwan ; Graduate Institute of Clinical Medicine Science, China Medical University, Taichung, Taiwan.
authors: Huei-Hsuan
authors: HH
authors: Cheng
authors: Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Miaoli, Taiwan ; Institute of Biotechnology, National Tsing Hua University, Hsin-Chu, Taiwan.
authors: Kai-Hsuan
authors: KH
authors: Wang
authors: Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Miaoli, Taiwan.
authors: Ling-yun
authors: LY
authors: Chu
authors: Metabolomic Medicine Research Center, China Medical University, Taichung, Taiwan ; Graduate Institute of Clinical Medicine Science, China Medical University, Taichung, Taiwan.
authors: Tzu-Ching
authors: TC
authors: Chang
authors: Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Miaoli, Taiwan.
authors: Cheng-Chin
authors: CC
authors: Kuo
authors: Metabolomic Medicine Research Center, China Medical University, Taichung, Taiwan ; Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Miaoli, Taiwan ; Institute of Biotechnology, National Tsing Hua University, Hsin-Chu, Taiwan.
authors: Kenneth K
authors: KK
authors: Wu
mesh_terms: D000893:Anti-Inflammatory Agents / Q000737:chemistry; D002454:Cell Differentiation; D049109:Cell Proliferation; D002851:Chromatography, High Pressure Liquid; D051546:Cyclooxygenase 2 / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology*; D020868:Gene Silencing; D006801:Humans; D007124:Immunoenzyme Techniques; D007249:Inflammation; D013058:Mass Spectrometry; D011401:Promoter Regions, Genetic; D034741:RNA, Small Interfering / Q000378:metabolism; D012685:Sepharose / Q000737:chemistry; D019809:Streptavidin / Q000737:chemistry; D014364:Tryptophan / Q000031:analogs & derivatives* / Q000737:chemistry; D050880:p300-CBP Transcription Factors / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D034741:RNA, Small Interfering; C027986:5-methoxytryptophan; D014364:Tryptophan; D012685:Sepharose; D019809:Streptavidin; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D050880:p300-CBP Transcription Factors