Altered brain lipid composition in cyclooxygenase-2 knockout mouse

Abstract

Cyclooxygenase (COX)-2 plays an important role in brain arachidonic acid (20:4n-6) metabolism, and its expression is upregulated in animal models of neuroinflammation and excitotoxicity. Our hypothesis was that brain lipid composition would be altered in COX-2 knockout (COX-2−/−) compared with wild-type (COX-2+/+) mice, reflecting the important role of COX-2 in brain lipid metabolism. Concentrations of different lipids were measured in high-energy microwaved brain from COX-2−/− and COX-2+/+ mice. Compared with the COX-2+/+ mouse brain, the brain of the COX-2−/− mouse had a statistically significant 15% increase in phosphatidylserine (PtdSer) and significant 37, 27, and 32% reductions in triacylglycerol and cholesterol concentrations and in the cholesterol-to-phospholipid ratio, respectively. The normalized concentration of palmitic acid (16:0) was increased in PtdSer, as was the brain concentration of unesterified arachidic acid (20:0). A lifetime absence of COX-2 produces multiple changes in brain lipid composition. These changes may be related to reported changes in fatty acid kinetics and in resistance to neuroinflammation and excitotoxicity in the COX-2−/− mouse.

Keywords

• fatty acids
• cholesterol
• phosphatidylserine