title: Histamine induces Egr-1 expression in human aortic endothelial cells via the H1 receptor-mediated protein kinase Cdelta-dependent ERK activation pathway.
abstract: Histamine, a potent inflammatory mediator, has multiple effects on the pathogenesis of atherosclerosis. This study investigates the effect of histamine on the expression of early growth response factor 1 (Egr-1), a master transcription factor that regulates the expression of an array of atherogenic genes in atherosclerotic lesions. Histamine markedly and rapidly induces Egr-1 mRNA and protein expression in primary human aortic endothelial cells (HAECs). Histamine-induced Egr-1 expression is dependent on the activation of the H1 receptor. Histamine also rapidly and transiently activates protein kinase C-delta (PKCdelta), extracellular signal-regulated kinase (ERK)1/2, p38 kinase, and c-Jun N-terminal kinase (JNK) prior to Egr-1 induction. Using specific pharmacological inhibitors and small interfering RNA technology, we determined that PKCdelta and ERK, but not p38 and JNK, mediate histamine-induced Egr-1 expression. Our data provide the first evidence that histamine regulates expression of Egr-1 in mammalian cells and demonstrate a novel role of PKCdelta in up-regulation of Egr-1 expression. The present study reveals the following regulatory mechanism: histamine up-regulates Egr-1 expression in primary HAECs via the H1 receptor and the PKCdelta-dependent ERK activation pathway. Our data also imply that CREB, a downstream component of the ERK pathway, regulates Egr-1 expression in HAECs. Importantly, these results suggest a central role of Egr-1 in histamine-induced gene expression and in histamine-induced vascular disease.
authors.affiliation: Department of Pathobiology, The University of Tennessee College of Veterinary Medicine, Knoxville, Tennessee 37996, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Hao
authors.forename: Mingqi
authors.initials: M
authors.lastname: Tan
authors.forename: Xuemin
authors.initials: X
authors.lastname: Xu
authors.forename: Mei-Zhen
authors.initials: MZ
authors.lastname: Cui
mesh_terms: D001011:Aorta / Q000378:metabolism* / Q000473:pathology; D050197:Atherosclerosis / Q000378:metabolism / Q000473:pathology; D050882:CREB-Binding Protein / Q000378:metabolism; D002478:Cells, Cultured; D051766:Early Growth Response Protein 1 / Q000096:biosynthesis*; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D004789:Enzyme Activation / Q000187:drug effects; D006632:Histamine / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism / Q000494:pharmacology*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D051745:Protein Kinase C-delta / Q000378:metabolism*; D011969:Receptors, Histamine H1 / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; D018836:Inflammation Mediators; D011969:Receptors, Histamine H1; D006632:Histamine; D050882:CREB-Binding Protein; C494363:CREBBP protein, human; D051745:Protein Kinase C-delta; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases