Repression of PDGF-R-α after cellular injury involves TNF-α, formation of a c-Fos-YY1 complex, and negative regulation by HDAC.
Wound healing is a complex dynamic process involving a variety of cell types, including fibroblasts that express and respond to cytokines and growth factors in the local microenvironment. The mechanisms controlling gene expression after injury at a transcriptional level are poorly understood. Here we show that decreased expression of a key receptor, PDGF-receptor (R)-α, after fibroblast injury is due to the release and paracrine activity of TNF-α. TNF-α inhibits PDGF-R-α expression and this involves formation of a c-Fos-Yin Yang 1 (YY1) complex and histone deacetylase (HDAC) activity. c-Fos, induced by TNF-α, negatively regulates PDGF-R-α transcription. Small interfering RNA (siRNA) targeting c-Fos or the zinc finger transcription factor YY1 inhibits TNF-α suppression of PDGF-R-α expression. Coimmunoprecipitation studies show that TNF-α stimulates the formation of a complex between c-Fos with YY1. Furthermore, chromatin immunoprecipitation (ChIP) analysis reveals the enrichment of c-Fos, YY1, and HDAC-1 at the PDGF-R-α promoter in cells exposed to TNF-α. With suberoylanilide hydroxamic acid (SAHA) and HDAC-1 siRNA, we demonstrate that HDAC mediates TNF-α repression of PDGF-R-α. These findings demonstrate that transcriptional repression of PDGF-R-α after fibroblast injury involves paracrine activity of endogenous TNF-α, the formation of a c-Fos-YY1 complex, and negative regulatory activity by HDAC.
Centre for Vascular Research, University of New South Wales, Sydney, Australia.
Ning
N
Zhang
Cecilia W S
CW
Chan
Estella
E
Sanchez-Guerrero
Levon M
LM
Khachigian
D000818:Animals; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism*; D006877:Hydroxamic Acids / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D011401:Promoter Regions, Genetic; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D000077337:Vorinostat; D050986:YY1 Transcription Factor / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D006877:Hydroxamic Acids; D016760:Proto-Oncogene Proteins c-fos; D034741:RNA, Small Interfering; D014409:Tumor Necrosis Factor-alpha; D050986:YY1 Transcription Factor; C494698:YY1 protein, human; D000077337:Vorinostat; D020796:Receptor, Platelet-Derived Growth Factor alpha; D006655:Histone Deacetylases