PT  - JOURNAL ARTICLE
AU  - Mana Mirjany
AU  - Lap Ho
AU  - Giulio Maria Pasinetti
TI  - Role of Cyclooxygenase-2 in Neuronal Cell Cycle Activity and Glutamate-Mediated Excitotoxicity
AID  - 10.1124/jpet.301.2.494
DP  - 2002 May 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 494--500
VI  - 301
IP  - 2
4099  - http://jpet.aspetjournals.org/content/301/2/494.short
4100  - http://jpet.aspetjournals.org/content/301/2/494.full
SO  - J Pharmacol Exp Ther2002 May 01; 301
AB  - In previous studies we found that neuronal overexpression of human cyclooxygenase (COX)-2 in transgenic mice potentiated excitotoxicity in vivo and in vitro. To clarify the molecular mechanisms involved in COX-2-mediated potentiation of excitotoxicity, we used cDNA microarray to identify candidate genes the expression of which is altered in the cerebral cortex of homozygous human hCOX-2 transgenic mice. We found that the mRNA expression of the cell cycle kinase (CDK) inhibitor-inhibitor kinase (INK) p18INK4, a specific inhibitor of CDK 4,6, which controls the activation of the retinoblastoma (Rb) tumor suppressor protein phosphorylation, was decreased in the brain of adult hCOX-2 homozygous transgenics. Conversely, chronic treatment of the hCOX-2 transgenics with the preferential COX-2 inhibitor nimesulide reversed the hCOX-2-mediated decrease of cortical p18INK4 mRNA expression in the brain. Further in vitro studies revealed that in primary cortico-hippocampal neurons derived from homozygous hCOX-2 transgenic mice, COX-2 overexpression accelerates glutamate-mediated apoptotic damage that is prevented by the CDK inhibitor flavoperidol. Moreover, treatment of wild-type primary cortico-hippocampal neuron cultures with the COX-2 preferential inhibitor nimesulide significantly attenuated glutamate-mediated apoptotic damage, which coincided with inhibition of glutamate-mediated pRb phosphorylation. These data indicate that hCOX-2 overexpression causes neuronal cell cycle deregulation in the brain and provides further rationale for targeting neuronal COX-2 in neuroprotective therapeutic research. The American Society for Pharmacology and Experimental Therapeutics