Nanoparticle-mediated simultaneous targeting of mitochondrial injury and inflammation attenuates myocardial ischemia-reperfusion injury

BACKGROUND: The opening of mitochondrial permeability transition pore and inflammation cooperatively progress myocardial ischemia-reperfusion (IR) injury, which hampers therapeutic effects of primary reperfusion therapy for acute myocardial in-farction. We examined the therapeutic effects of nanoparticle-mediated medicine that simultaneously targets mitochondrial permeability transition pore and inflammation during IR injury. METHODS AND RESULTS: We used mice lacking cyclophilin D (CypD, a key molecule for mitochondrial permeability transition pore opening) and C-C chemokine receptor 2 and found that CypD contributes to the progression of myocardial IR injury at early time point (30–45 minutes) after reperfusion, whereas C-C chemokine receptor 2 contributes to IR injury at later time point (45–60 minutes) after reperfusion. Double deficiency of CypD and C-C chemokine receptor 2 enhanced cardioprotec-tion compared with single deficiency regardless of the durations of ischemia. Deletion of C-C chemokine receptor 2, but not deletion of CypD, decreased the recruitment of Ly-6C^high monocytes after myocardial IR injury. In CypD-knockout mice, administration of interleukin-1β blocking antibody reduced the recruitment of these monocytes. Combined administration of polymeric nanoparticles composed of poly-lactic/glycolic acid and encapsulating nanoparticles containing cyclosporine A or pitavastatin, which inhibit mitochondrial permeability transition pore opening and monocyte-mediated inflammation, respec-tively, augmented the cardioprotection as compared with single administration of nanoparticles containing cyclosporine A or pitavastatin after myocardial IR injury. CONCLUSIONS: Nanoparticle-mediated simultaneous targeting of mitochondrial injury and inflammation could be a novel therapeutic strategy for the treatment of myocardial IR injury.