title: Role of cyclooxygenase-2 induction by transcription factor Sp1 and Sp3 in neuronal oxidative and DNA damage response.
abstract: Cyclooxygenase-2 (COX-2) has been implicated in neuronal survival and death. However, the precise regulatory mechanisms involved in COX-2 function are unclear. In the present study we found that COX-2 is induced in response to glutathione depletion-induced oxidative stress in primary cortical neurons. Two proximal specific Sp1 and Sp3 binding sites are responsible for the COX-2 promoter activity under normal as well as oxidative stress conditions through enhanced Sp1 and Sp3 DNA binding activity. Site-directed mutagenesis confirmed that -268/-267 positions serve as specific Sp1 and Sp3 recognition sites under oxidative stress. Enforced expression of Sp1 and Sp3 using HSV vectors increased the promoter activity, transcription, and protein level of COX-2 in cortical neurons. The dominant negative form of Sp1 abrogated the oxidative stress-induced promoter activity and expression of COX-2. We also demonstrated that adenovirus-mediated COX-2 gene delivery protected neurons from DNA damage induced by oxidative, genotoxic, and excitotoxic stresses and by ischemic injury. Moreover, COX-2(-/-) cortical neurons were more susceptible to DNA damage-induced cell death. These results indicate that in primary neurons Sp1 and Sp3 play an essential role in the modulation of COX-2 transcription, which mediates neuronal homeostasis and survival by preventing DNA damage in response to neuronal stress.
authors.affiliation: Geriatric Research Education and Clinical Center, Bedford Veteran's Affairs Medical Center, 200 Springs Rd., Bedford, MA 01730, USA.
authors.forename: Junghee
authors.initials: J
authors.lastname: Lee
authors.forename: Bela
authors.initials: B
authors.lastname: Kosaras
authors.forename: Hossein
authors.initials: H
authors.lastname: Aleyasin
authors.forename: Jeong A
authors.initials: JA
authors.lastname: Han
authors.forename: David S
authors.initials: DS
authors.lastname: Park
authors.forename: Rajiv R
authors.initials: RR
authors.lastname: Ratan
authors.forename: Neil W
authors.initials: NW
authors.lastname: Kowall
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Ferrante
authors.forename: Sam W
authors.initials: SW
authors.lastname: Lee
authors.forename: Hoon
authors.initials: H
authors.lastname: Ryu
mesh_terms: D000818:Animals; D001483:Base Sequence; D002545:Brain Ischemia / Q000235:genetics / Q000473:pathology; D002470:Cell Survival; D002540:Cerebral Cortex / Q000201:enzymology*; D003001:Cloning, Molecular; D051545:Cyclooxygenase 1 / Q000235:genetics; D051546:Cyclooxygenase 2 / Q000172:deficiency / Q000235:genetics*; D004249:DNA Damage; D017931:DNA Primers; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D009474:Neurons / Q000166:cytology / Q000473:pathology / Q000502:physiology*; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D051704:Sp2 Transcription Factor / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D016329:Sp1 Transcription Factor; D051704:Sp2 Transcription Factor; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2