title: Spontaneous Glutamatergic Synaptic Activity Regulates Constitutive COX-2 Expression in Neurons: OPPOSING ROLES FOR THE TRANSCRIPTION FACTORS CREB (cAMP RESPONSE ELEMENT BINDING) PROTEIN AND Sp1 (STIMULATORY PROTEIN-1).
abstract: Burgeoning evidence supports a role for cyclooxygenase metabolites in regulating membrane excitability in various forms of synaptic plasticity. Two cyclooxygenases, COX-1 and COX-2, catalyze the initial step in the metabolism of arachidonic acid to prostaglandins. COX-2 is generally considered inducible, but in glutamatergic neurons in some brain regions, including the cerebral cortex, it is constitutively expressed. However, the transcriptional mechanisms by which this occurs have not been elucidated. Here, we used quantitative PCR and also analyzed reporter gene expression in a mouse line carrying a construct consisting of a portion of the proximal promoter region of the mouse COX-2 gene upstream of luciferase cDNA to characterize COX-2 basal transcriptional regulation in cortical neurons. Extracts from the whole brain and from the cerebral cortex, hippocampus, and olfactory bulbs exhibited high luciferase activity. Moreover, constitutive COX-2 expression and luciferase activity were detected in cortical neurons, but not in cortical astrocytes, cultured from wild-type and transgenic mice, respectively. Constitutive COX-2 expression depended on spontaneous but not evoked excitatory synaptic activity and was shown to be N-methyl-d-aspartate receptor-dependent. Constitutive promoter activity was reduced in neurons transfected with a dominant-negative cAMP response element binding protein (CREB) and was eliminated by mutating the CRE-binding site on the COX-2 promoter. However, mutation of the stimulatory protein-1 (Sp1)-binding site resulted in an N-methyl-d-aspartate receptor-dependent enhancement of COX-2 promoter activity. Basal binding of the transcription factors CREB and Sp1 to the native neuronal COX-2 promoter was confirmed. In toto, our data suggest that spontaneous glutamatergic synaptic activity regulates constitutive neuronal COX-2 expression via Sp1 and CREB protein-dependent transcriptional mechanisms.
authors.affiliation: From the Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, New York 13210, shewett@syr.edu.
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Hewett
authors.affiliation: From the Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, New York 13210.
authors.forename: Jingxue
authors.initials: J
authors.lastname: Shi
authors.affiliation: From the Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, New York 13210.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Gong
authors.affiliation: the Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, Georgia 30912, and.
authors.forename: Krishnan
authors.initials: K
authors.lastname: Dhandapani
authors.affiliation: the Department of Medicine, University of Connecticut Health Center, Farmington, Connecticut 06030.
authors.forename: Carol
authors.initials: C
authors.lastname: Pilbeam
authors.affiliation: From the Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, New York 13210, jhewett@syr.edu.
authors.forename: James A
authors.initials: JA
authors.lastname: Hewett
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D018698:Glutamic Acid / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009473:Neuronal Plasticity; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; D016194:Receptors, N-Methyl-D-Aspartate; D016329:Sp1 Transcription Factor; D018698:Glutamic Acid; D000242:Cyclic AMP; D051546:Cyclooxygenase 2
keywords: N-methyl-d-aspartate receptor (NMDA receptor, NMDAR); cAMP response element-binding protein (CREB); constitutive expression; cyclooxygenase (COX); neuron; specificity protein 1 (Sp1); transcription; transcriptional regulation