Simultaneous targeting of mitochondria and monocytes enhances neuroprotection against ischemia–reperfusion injury

Abstract

Ischemia-reperfusion injury impairs the efficacy of reperfusion therapy after ischemic stroke. cyclophilin D (cypD)-mediated openings of mitochondrial permeability transition pore (mptp) and subsequent monocyte-mediated inflammation are considered as major mechanisms of reperfusion injury. However, no medical therapies are currently available. Therefore, we have tested a hypothesis that simultaneous targeting of mPTP and inflammation confers substantial neuroprotection after cerebral ischemia-reperfusion. To address this point, we prepared CypD knockout mice, CC chemokine receptor 2 (CCR2) knockout mice and CypD/CCR2 double knockout mice. These mice were subjected to 60 min transient cerebral ischemia by occluding middle cerebral arteries. Neurological deficits evaluated 3 days after reperfusion were significantly attenuated in CypD/CCR2 double knockout mice as compared to wild-type mice and other single knockout mice. Then, we have prepared polymeric nanoparticles containing cyclosporine A (CsA-NPs) and pitavastatin (Pitava-NPs), targeting mPTP opening and inflammation, respectively. Simultaneous administration of CsA-NP and Pitava-NP at the time of reperfusion also decreased infarct size and attenuated neurological deficits as compared to control nanoparticles and single administration of CsA-NPs or Pitava-NPs. These results indicate that simultaneous targeting of the mPTP opening and monocyte-mediated inflammation could be a novel strategy for better neurological outcomes in patients with ischemic stroke. Innovative therapeutic strategies for protecting the brain from ischemia-reperfusion (IR) injury are necessary to decrease infarct volume and improve clinical outcomes after reperfusion therapy for the treatment of ischemic stroke 1 .Within several minutes after reperfusion, opening of mitochondrial permeability transition pore (mPTP) triggers cell deaths in tissues exposed to IR injury 2. Inflammatory monocytes, Ly6C high CCR2 + in mice or CD14 high CD16 − in humans, accumulate to the cerebral tissue as early as several hours after reperfusion and also trigger cell death 3-8. Cyclosporine A (CsA) is a widely used drug after organ transplantation which binds to cyclophilin A and inhibits calcineurin activities in T cells, and thus exerts immunosuppressive effects. CsA also binds to cyclophilin D (CypD), which results in inhibition of mPTP opening and subsequent cell deaths 9. In experimental animals, intravenous administered CsA decreases infarct size 10. In clinical trials, however, intravenously administered CsA (2.0 mg/kg) failed to improve neurological outcomes after ischemic stroke 11 .This discrepancy raises at least two possibilities. First, monotherapy targeting only mPTP was insufficient in humans. Second, drug delivery to target organ was insufficient. In this study, we prepared mice lacking both CypD and CCR2 to elucidate whether targeting two mechanisms, i.e. mPTP opening and inflammation, confers substantial neuroprotection as evidenced by

Melatonin-Induced Postconditioning Suppresses NMDA Receptor through Opening of the Mitochondrial Permeability Transition Pore via Melatonin Receptor in Mouse Neurons

“…This result appears to differ from other previous findings [ 57 ] but is consistent with our previous report [ 11 ]. Okahara et al reported that both the mPTP opening and inflammation are necessary to improve the neurological outcomes after cerebral ischemia-reperfusion injury on experiments using cyclophilin D and CC chemokine receptor 2-knockout mice [ 60 ]. Hawrysh et al reported the mechanism of tolerance against anoxia in turtle neurons, finding that anoxia activates mito-K ATP channels, leading to matrix depolarization and triggering the transient opening of the mPTP and Ca 2+ release via the mPTP, and ultimately silencing the NMDARs in turtle neurons [ 6 ].…”

Smac/DIABLO can predict postoperative delirium in elderly patients after cardiac surgery : A prospective nested case-control study

“…Mitochondrial-targeted therapy of the nervous system gradually started from fundamental study to clinical application. Several novel therapeutic agents, such as cyclosporine A, Nicorandilan, and Mitochondrial calcium uniporter (MUC) by adjust the mitochondrion channel, reducing oxidative stress and Ca2+ overload, inhibiting ROS burst, protect nerve cells [34,35]. Further researches on these mitochondrial-targeted drugs might provide an available strategy for future POD treatment.…”

Mitochondria-Targeted Drug Delivery in Cardiovascular Disease: A Long Road to Nano-Cardio Medicine

“…Along the same line, in another work, PLGA-based polymeric NPs containing CsA (CsA-NPs) and pitavastatin (Pitava-NPs) were simultaneously administered to target mitochondrial dysfunction and monocyte-mediated inflammation in a mouse model of acute cerebral IR [ 47 ]. Through blocking MPTP opening and chemokine receptor-2-dependent inflammation, concomitant administration of CsA-NPs and Pitava-NPs at the time of reperfusion decreased infarct size and attenuated neurological deficits as compared to single administration of CsA-NPs or Pitava-NPs ( Figure 5 ).…”

“…Through blocking MPTP opening and chemokine receptor-2-dependent inflammation, concomitant administration of CsA-NPs and Pitava-NPs at the time of reperfusion decreased infarct size and attenuated neurological deficits as compared to single administration of CsA-NPs or Pitava-NPs ( Figure 5 ). Given the crucial involvement of MPTP opening and inflammation in promoting cardiac injuries, it is conceivable that a similar NP-based combination therapy could also provide benefits in CVD [ 47 ]. Finally, the highly versatile Mito-porter DDS can potentially be employed to achieve mitochondria-targeted multiple delivery of protective agents, including nutraceutics and CsA, for a more efficient combination therapy in CVD ( Figure 5 ).…”