Transcellular biosynthesis of cysteinyl leukotrienes in rat neuronal and glial cells

Abstract

Leukotrienes are mediators of inflammation that belong to a family of lipids derived from arachidonic acid by the action of 5-lipoxygenase. Leukotrienes have been detected in the central nervous system in association with different pathological events, but little is known about their biosynthesis or function in the brain. When rat neurons and glial cells in primary culture were stimulated with the calcium ionophore, no significant biosynthesis of leukotrienes was detected using liquid chromatography/mass spectrometry (LC/MS) techniques. However, when exogenous LTA4 was added to these cultured cells, both neurons and glia were able to synthesize LTC4. Activated neutrophils are known to supply LTA4 to other cells for transcellular biosynthesis of cysteinyl-leukotrienes. Since neutrophils can infiltrate brain tissue after stroke or traumatic brain injury, we examined whether neutrophils play a similar role in the central nervous system. When peripheral blood neutrophils were co-cultured with rat neurons, glia cells, and then stimulated with calcium ionophore, a robust production of LTC4, LTD4, and LTE4 was observed, revealing that neurons and glia can participate in the transcellular mechanism of leukotriene biosynthesis. The formation of LTC4 through this mechanism may be relevant in the genesis and progression of the inflammatory response as a result of brain injury. © 2007 The Authors.