Macrophage dynamics in kidney repair: elucidation of a COX-2–dependent MafB pathway to affect macrophage differentiation

Cylocloxygenase-2 is an important mediator of arachidonic acid metabolism. Pan et al. recently identified a robust increase in the expression of cylocloxygenase-2 in proresolving macrophages (M2) during the repair phase of acute kidney injury. The investigators determined the prostaglandin E2 was produced in macrophages and demonstrated that signaling through the E-type prostanoid receptor 4 stimulated the expression of the anti-inflammatory transcription factor MafB. MafB was further shown to be essential for macrophage differentiation and mediation of the intrinsic repair response following experimental acute kidney injury.