title: Selective up-regulation of P2X4-receptor gene expression by interferon-gamma in vascular endothelial cells.
abstract: Extracellular nucleotides are involved in the development of vascular inflammation. However, little is known about whether effects of nucleotides are modulated under inflammatory states. We investigated effects of interferon-gamma (INF-gamma) on ATP-induced responses in vascular endothelial cells. Treatment of human umbilical vein endothelial cells (HUVECs) with IFN-gamma for 24 h resulted in an enhancement of the ATP-induced increase in intracellular Ca2+ concentration ([Ca2+]i) without affecting the UTP-induced one. The increased Ca2+ response to ATP in IFN-gamma-treated cells was dependent on the extracellular Ca2+, and was not inhibited by the phospholipase C inhibitor U73122. RT-PCR and Western blotting revealed that HUVECs dominantly expressed P2X4 receptor. IFN-gamma increased P2X4-receptor mRNA and protein, accompanied by an increase in ATP-triggered membrane current. IFN-gamma did not affect P2X4-receptor mRNA stability, but increased P2X4-receptor gene transcription in a cycloheximide-insensitive manner. IFN-gamma stimulated phosphorylation of signal transducer and activator of transcription-1 (STAT1). Epigallocatechin gallate (EGCG), an inhibitor of STAT1-mediated signaling, and AG490, a Janus kinase (JAK) inhibitor, impaired P2X4-receptor mRNA up-regulation by IFN-gamma. These results indicate that INF-gamma selectively increases P2X4-receptor gene expression, leading to an up-regulation of purinergic signaling in vascular endothelial cells.
authors.affiliation: Department of Pharmacology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Yan
authors.initials: Y
authors.lastname: Tang
authors.forename: Isao
authors.initials: I
authors.lastname: Matsuoka
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Ono
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Inoue
authors.forename: Junko
authors.initials: J
authors.lastname: Kimura
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000187:drug effects / Q000378:metabolism*; D058848:Receptors, Purinergic P2X4; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050794:STAT1 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects; D014471:Umbilical Veins / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects*; D014544:Uridine Triphosphate / Q000378:metabolism
chemical_list: C548226:P2RX4 protein, human; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; D058848:Receptors, Purinergic P2X4; D050794:STAT1 Transcription Factor; D007371:Interferon-gamma; D000255:Adenosine Triphosphate; D002118:Calcium; D014544:Uridine Triphosphate