Cardioprotective Effect of Morphine and a Blocker of Glycogen Synthase Kinase 3β, SB216763 [3-(2,4-Dichlorophenyl)-4(1-methyl-1H-indol-3-yl)-1H-pyrrole-2,5-dione], via Inhibition of the Mitochondrial Permeability Transition Pore

Abstract

Morphine has been shown to protect the myocardium against ischemia-reperfusion injury through inhibition of glycogen synthase kinase-3␤ (GSK-3␤). Given that GSK-3␤ is known to modulate the mitochondrial permeability transition pore (mPTP), we investigated the role of mPTP in the cardioprotective effect of morphine and the GSK-3␤ inhibitor SB216763 [SB; 3-(2,4-dichlorophenyl)-4(1-methyl-1H-indol-3-yl)-1H-pyrrole-2,5-dione] during ischemia-reperfusion. Both morphine (0.3 mg/kg) and SB (0.6 mg/kg) reduced infarct size in a model of regional myocardial ischemia-reperfusion in rats (13 Ϯ 1 and 14 Ϯ 3% of the area at risk versus 33 Ϯ 4% in controls; p Ͻ 0.05). Morphine and SB protected the ischemic myocardium against Ca 2ϩ -induced mPTP opening as demonstrated by the increased capacity of mitochondria to retain Ca 2ϩ when they were isolated from the ischemic zone 10 min after the onset of reperfusion (59 Ϯ 8 and 66 Ϯ 3 versus 29.5 Ϯ 6 nmol Ca 2ϩ /mg ⅐ protein, respectively; p Ͻ 0.05). This was associated with a restoration of mitochondrial oxidative phosphorylation parameters. In isolated adult rat cardiomyocytes subjected to anoxiareoxygenation, morphine (2 M), SB (3 M), and the direct mPTP inhibitor cyclosporine A (3 M) delayed mPTP opening as assessed by the calcein loading Co 2ϩ -quenching technique. This was accompanied by an increase in cell survival as measured by nuclear staining with propidium iodide. These in vitro effects of morphine on inhibition of mPTP opening during anoxia-reoxygenation were suppressed by the phosphatidylinositol 3-kinase (PI3-kinase) inhibitor wortmannin (0.1 M). These data indicate that the infarct-limiting effect of morphine and SB is linked by a cause-effect relationship, which leads to an increased mitochondrial resistance and inhibition of mPTP opening through the PI3-kinase pathway and subsequent inactivation of GSK-3␤.There are many investigations that suggest that the opening of mitochondrial permeability transition pore (mPTP) is involved in myocardial ischemia-reperfusion injury (Di Lisa and Bernardi, 2006;Halestrap, 2006;Javadov and Karmazyn, 2007) and that raising the threshold for mPTP opening is a relevant strategy to provide cardioprotection (Tissier et al., 2008).

RETRACTED: Glycogen synthase kinase 3β transfers cytoprotective signaling through connexin 43 onto mitochondrial ATP-sensitive K + channels

“…Some animals were administered vehicle control (1% DMSO in 0.9% NaCl solution) and 70 or 600 μg/kg SB216763 i.v. (SigmaAldrich Chemical Co.) 5 min before coronary artery occlusion, as indicated (3,41). In some animals, TAT 47-57 -conjugated RRNYRRNY or TAT 47-57 -conjugated RRPPYN control was administered by an i.p.…”

The SR/ER-mitochondria calcium crosstalk is regulated by GSK3β during reperfusion injury

“…Ventricular cardiomyocytes were isolated using enzymatic digestion according to previously described procedure. 35,36 Briefly, WT mice were anesthetized with pentobarbital (70 mg/kg) (Sanofi Santé Animale, Libourne, France) and the heart was quickly harvested and retrogradely perfused at 37°C for 6-8 min with a perfusion buffer (113 mM NaCl, 4.7 mM KCl, 0.6 mM KH 2 PO 4 , 0.6 mM Na 2 HPO 4 , 1.2 mM MgSO 4 , 12 mM NaHCO 3 , 10 mM KHCO 3 , 10 mM HEPES, 30 mM Taurine, pH 7.4) containing 10 mM 2,3-butanedione, 5.5 mM glucose, 12.5 μM CaCl 2 , 0.1 mg/ml of liberase (Roche) and 0.14 mg/ml trypsin (Sigma). Isolated myocytes were then maintained in culture in laminin-(10 μg/ml) precoated dishes with M199 medium (Invitrogen) and allowed to attach for 2 h before analysis.…”

GSK-3.BETA., a Therapeutic Target for Cardiomyocyte Protection

“…Although pre-clinical studies except for one using mice 55,57,60,72,73,75 have shown that inhibitors of GSK-3β could limit infarct size in animal models of AMI, efficacy of the GSK-3β inhibitors has not yet been assessed in human cardiac tissues. However, protection of the human heart was reportedly achieved by an inhibitor of mPTP, cyclosporine A, 110 ischemic preconditioning, [113][114][115] and postconditioning.…”

“…Direct inhibition of GSK-3β by the use of structurally different pharmacological inhibitors (SB-216763, lithium chloride) administered before either ischemia or reperfusion limits infarct size. 55,57,60,72,73 It is interesting to note that inhibitors of GSK-3β increase the level of phospho-GSK-3β, which is explained by GSK-3β-mediated positive regulation of protein phosphatase-1 (Figure 3). 74 Nevertheless, these findings support the notion that inactivation of GSK-3β by phosphorylation at Ser9 is a common mechanism of protection of cardiomyocytes against necrosis in many cardioprotective interventions.…”