Protective effect of MFG-E8 after cutaneous ischemia-reperfusion injury.

We recently demonstrated that the secreted glycoprotein and integrin-ligand MFG-E8 promotes cutaneous wound healing by enhancing angiogenesis. Several studies have identified potential roles for MFG-E8 in regulation of ischemia-reperfusion (I/R) injury in the brain, kidney, and liver. Our objective was to assess the role of MFG-E8 in the formation of skin ulcers using a murine model of cutaneous I/R injury-cutaneous pressure ulcers. Cutaneous I/R was performed by trapping the dorsal skin between two magnetic plates for 12 hours, followed by plate removal. Expression of MFG-E8 increased in the dermis during ischemia, and then decreased after reperfusion. Administration of recombinant (r)MFG-E8 in I/R areas at the beginning of reperfusion significantly inhibited the formation of cutaneous pressure ulcers, and the number of CD31(+) vessel and NG2(+) pericytes in wounds were increased in I/R mice treated with rMFG-E8. The number of M1 macrophages and the amount of proinflammatory mediators monocyte chemotactic protein-1,induced nitric oxide synthase, IL-6, tumor necrosis factor-α, and IL-1β in the wound area were reduced by the administration of rMFG-E8. We conclude that MFG-E8 may inhibit the formation of pressure ulcers induced by cutaneous I/R injury by regulating angiogenesis and inflammation. Exogenous application of MFG-E8 might have therapeutic potential for cutaneous I/R injuries, including decubitus ulcers and Raynaud's phenomenon-induced digital ulcers.