COX-2

Cyclooxygenase-2 (COX-2) is an inducible enzyme catalyzing the conversion of arachidonic acid to prostaglandin endoperoxides, central to prostanoid biosynthesis and inflammatory signaling^[1][2]. Mechanistically, COX-2 activity is regulated by both its catalytic and allosteric subunits, allowing modulation by fatty acids and selective inhibitors, distinguishing it from constitutive COX-1^[2]. COX-2 is strongly upregulated in response to pro-inflammatory cytokines, hypoxia, and tumor microenvironment signals, orchestrating prostaglandin E₂ (PGE₂) production and downstream activation of NF-κB and PI3K-Akt pathways^[3][4][5]. In disease models, COX-2 contributes to cancer progression, atherosclerosis, and migraine through modulation of immune responses, vascular smooth muscle activity, and neuronal-glial interactions^[6][7][5]. Compared with COX-1, COX-2 expression is more context-dependent and spatially regulated, being highly inducible in endothelial cells, arterial versus venous smooth muscle, and neuronal populations under stress or inflammatory stimuli^[8][9][10]. Experimental studies demonstrate COX-2 as a critical mediator of ischemic preconditioning in the heart, providing cardioprotection via PGE₂ and PGI₂ signaling^[11]. Selective COX-2 inhibitors, including synthetic NSAIDs and dual COX/LOX modulators, are utilized to interrogate COX-2 function and develop anti-inflammatory therapies with reduced gastrointestinal and cardiovascular side effects^[3][12]. Agonist studies further highlight receptor-mediated induction of COX-2, exemplifying its role in colon carcinoma and trigeminal ganglia models^[13][7].