The resolution of acute inflammation is an active process driven by specialized pro-resolving mediators (SPMs). Which lipoxin is generated from arachidonic acid via 15-lipoxygenase and acts as a 'stop signal' for neutrophil recruitment while promoting macrophage efferocytosis?
- A Lipoxin A4 (LXA4) generated via the 15-LOX pathway in epithelial cells and transcellular biosynthesis ✓
- B Resolvin D1 (RvD1) derived from docosahexaenoic acid (DHA) via cytochrome P450
- C Protectin D1 (PDn1) from DHA via 15-LOX in neurons and retinal cells
- D Maresins (MaR1) generated from DHA in macrophages via 12-LOX
Explanation
Lipoxin A4 (LXA4) is the prototype aspirin-triggered and endogenous SPM derived from arachidonic acid. It is generated via sequential 15-LOX (in epithelial cells or eosinophils) and 5-LOX (in leukocytes) activity — transcellular biosynthesis being a hallmark. LXA4 acts on ALX/FPR2 receptors to block neutrophil transmigration, stimulate macrophage phagocytosis of apoptotic neutrophils (efferocytosis), and reduce pro-inflammatory cytokine production. Resolvins D and E are EPA/DHA-derived; protectins and maresins also come from DHA but via different biosynthetic enzymes.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.