Cyclooxygenase-2 (COX-2) in the Central Nervous System (COX-2)

Cyclooxygenase-2 (COX-2), officially designated prostaglandin-endoperoxide synthase 2 (PTGS2), is an inducible enzyme found in the central nervous system that catalyzes the conversion of arachidonic acid to prostaglandins, particularly prostaglandin E2 (PGE2).[1][6] In the brain, COX-2 is constitutively expressed in glutamatergic neurons of the cerebral cortex, hippocampus, and amygdala, and becomes further upregulated in response to inflammatory stimuli, cytokines, seizure activity, and neuronal activation.[1][2][4] COX-2 plays a critical physiological role in synaptic transmission, long-term potentiation, memory consolidation, and neural plasticity through its production of PGE2 and its interactions with endocannabinoid signaling.[1][2] However, excessive COX-2 expression and activity contribute to neuropathology in multiple neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and in acute conditions such as traumatic brain injury and stroke-induced ischemia, primarily through enhanced glutamate excitotoxicity and neuroinflammation.[1][2][4] COX-2 is a validated therapeutic target; selective COX-2 inhibitors such as celecoxib and other NSAIDs reduce neuroinflammation and provide neuroprotection in animal models, though their clinical use remains complicated by cardiovascular and gastrointestinal safety concerns and the need to preserve COX-2's normal physiological functions in memory and cognition.[2][3][4]

Other names

Prostaglandin-endoperoxide synthase 2PTGS2Inducible cyclooxygenaseCOX-2

NSAIDs and selective COX-2 inhibitors block COX-2 catalytic activity, thereby reducing the conversion of arachidonic acid to prostaglandins and subsequently decreasing the production of prostaglandin E2. This enzyme inhibition suppresses excessive excitatory glutamatergic neurotransmission, enhances endocannabinoid signaling by preventing their metabolism, reduces neuroinflammation by inhibiting microglial activation, and prevents neuronal excitotoxicity.