Norepinephrine enhances the LPS-induced expression of COX-2 and secretion of PGE₂in primary rat microglia

• Main Authors: Candelario-Jalil Eduardo, de Oliveira Antonio CP, Haake Elisabeth, Fiebich Bernd L, Schlachetzki Johannes CM, Heneka Michael T, Hüll Michael
• Format: Article
• Language: English
• Published: BMC 2010-01-01
• Series: Journal of Neuroinflammation
• Online Access: http://www.jneuroinflammation.com/content/7/1/2

<p>Abstract</p> <p>Background</p> <p>Recent studies suggest an important role for neurotransmitters as modulators of inflammation. Neuroinflammatory mediators such as cytokines and molecules of the arachidonic acid pathway are generated and released by microglia. The monoamine norepinephrine reduces the production of cytokines by activated microglia <it>in vitro</it>. However, little is known about the effects of norepinephrine on prostanoid synthesis. In the present study, we investigate the role of norepinephrine on cyclooxygenase- (COX-)2 expression/synthesis and prostaglandin (PG)E₂production in rat primary microglia.</p> <p>Results</p> <p>Interestingly, norepinephrine increased COX-2 mRNA, but not protein expression. Norepinephrine strongly enhanced COX-2 expression and PGE₂production induced by lipopolysaccharide (LPS). This effect is likely to be mediated by β-adrenoreceptors, since β-, but not α-adrenoreceptor agonists produced similar results. Furthermore, β-adrenoreceptor antagonists blocked the enhancement of COX-2 levels induced by norepinephrine and β-adrenoreceptor agonists.</p> <p>Conclusions</p> <p>Considering that PGE₂displays different roles in neuroinflammatory and neurodegenerative disorders, norepinephrine may play an important function in the modulation of these processes in pathophysiological conditions.</p>