Role of cyclooxygenase-2 induction by transcription factor Sp1 and Sp3 in neuronal oxidative and DNA damage response.
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.
Lee
Junghee
J
Geriatric Research Education and Clinical Center, Bedford Veteran's Affairs Medical Center, 200 Springs Rd., Bedford, MA 01730, USA.
Kosaras
Bela
B
Aleyasin
Hossein
H
Han
Jeong A
JA
Park
David S
DS
Ratan
Rajiv R
RR
Kowall
Neil W
NW
Ferrante
Robert J
RJ
Lee
Sam W
SW
Ryu
Hoon
H
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*
D017931:DNA Primers; D016329:Sp1 Transcription Factor; D051704:Sp2 Transcription Factor; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2