Cyclooxygenase inhibition in ischemic brain injury

TL;DR

This review explores the roles of COX-1 and COX-2 enzymes in ischemic brain injury, discussing their biochemistry, expression, and the potential of COX inhibitors as neuroprotective therapies.

Contribution

It provides a comprehensive analysis of COX isoforms' involvement in ischemic brain damage and evaluates the therapeutic potential of selective COX inhibition.

Findings

COX-2 expression is dramatically induced after ischemia.

Selective COX inhibitors show potential neuroprotective effects.

Genetic knockout models help clarify COX roles in ischemic injury.

Abstract

Neuroinflammation is one of the key pathological events involved in the progression of brain damage caused by cerebral ischemia. Metabolism of arachidonic acid through cyclooxygenase (COX) enzymes is known to be actively involved in the neuroinflammatory events leading to neuronal death after ischemia. Two isoforms of COX, termed COX-1 and COX-2, have been identified. Unlike COX-1, COX-2 expression is dramatically induced by ischemia and appears to be an effector of tissue damage. This review article will focus specifically on the involvement of COX isozymes in brain ischemia. We will discuss issues related to the biochemistry and selective pharmacological inhibition of COX enzymes, and further refer to their expression in the brain under normal conditions and following excitotoxicity and ischemic cerebral injury. We will review present knowledge of the relative contribution of each COX isoform to the brain ischemic pathology, based on data from investigations utilizing selective COX-1/COX-2 inhibitors and genetic knockout mouse models. The mechanisms of neurotoxicity associated with increased COX activity after ischemia will also be examined. Finally, we will provide a critical evaluation of the therapeutic potential of COX inhibitors in cerebral ischemia and discuss new targets downstream of COX with potential neuroprotective ability.