Abstract
15-series prostaglandins (PGE₂s) and isoprostanes (isoPGE₂s) are robust biomarkers of oxidative stress, possess potent biological activity, and may be derived through cyclooxygenase or free radical pathways. Thus, their quantification is critical in understanding many biological processes where PG, isoPG, or oxidative stress are involved. LC/MS/MS methods allow a highly selective, sensitive, simultaneous analysis for prostanoids without derivatization. However, the LC/MS/MS methods currently used do not allow for simultaneous separation of the major brain PGE₂/D₂) and isoPGE₂ without derivatization and multiple HPLC separations. The developed LC/MS/MS method allows for the major brain PGE₂/PGD₂/isoPGE₂ such as PGE₂, entPGE₂, 8-isoPGE₂, 11β-PGE₂, PGD₂, and 15(R)-PGD₂ to be separated and quantified without derivatization. The method was validated by analyzing free and esterified isoPGE₂ in mouse brains fixed with head-focused microwave irradiation before or after global ischemia. Using the developed method, we report for the first time the esterified isoPGE₂ levels in brain tissue under basal conditions and upon global ischemia and demonstrate a nonreleasable pool of esterified isoPG upon ischemia. In addition, we demonstrated that PGE₂s found esterified in the sn-2 position in phospholipids are derived from a free radical nonenzymatic pathway under basal conditions. Our method for brain PG analysis provides a high level of selectivity to detect changes in brain PG and isoPG mass under both basal and pathological conditions.
Highlights
15-series prostaglandins (PGE2s) and isoprostanes are robust biomarkers of oxidative stress, possess potent biological activity, and may be derived through cyclooxygenase or free radical pathways
We developed an LC/MS/MS method that allows for the major brain PGE2/D2 series molecules such as PGD2, 15(R)-PGD2, PGE2, entPGE2, 8-isoPGE2, and 11-PGE2 to be separated and quantified without derivatization and validated the method by analyzing free and esterified isoPGE2 in brains fixed with headfocused microwave irradiation before or after global ischemia
We report for the first time esterified isoPGE2 levels in brain tissue under basal conditions and upon global ischemia and demonstrate a nonreleasable pool of isoPG esterified onto brain PL
Summary
15-series prostaglandins (PGE2s) and isoprostanes (isoPGE2s) are robust biomarkers of oxidative stress, possess potent biological activity, and may be derived through cyclooxygenase or free radical pathways. Their quantification is critical in understanding many biological processes where PG, isoPG, or oxidative stress are involved. We demonstrated that PGE2s found esterified in the sn-2 position in phospholipids are derived from a free radical nonenzymatic pathway under basal conditions. Prostaglandins (PGs) are important signaling molecules that are ubiquitously produced in many tissues and regulate many physiological functions under both normal and pathophysiological conditions In the brain, they modulate synaptic plasticity through modulation of adrenergic, noradrenergic, and glutamatergic neurotransmission and regulation of membrane excitability [1,2,3,4].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
