Division of Cardiovascular Medicine, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA.
J Pharmacol Exp Ther. 2010 Mar;332(3):898-905. doi: 10.1124/jpet.109.162602. Epub 2009 Dec 15.
Parstatin, the N-terminal 41-amino-acid peptide cleaved by thrombin from the protease-activated receptor 1, protects against rat myocardial ischemia and reperfusion injury. In this study, we determined that the parstatin fragment 1-26, the putative signal peptide of protease-activated receptor 1, contains the functional domain of parstatin. We assessed a synthesized parstatin(1-26) peptide in an in vivo rat model of myocardial regional ischemia-reperfusion injury (n = 6/group). Infarct size in control rat hearts was 58 +/- 1% area at risk. Parstatin(1-26) was able to reduce infarct size to 13 +/- 1% (P < 0.001) and 22 +/- 1% area at risk (P < 0.01) when given before or after reperfusion. The infarct-sparing effects of parstatin(1-26) were abolished by inhibition of G(i) proteins (pertussis toxin), phosphoinositide 3-kinase/Akt (wortmannin), nitric-oxide synthase (NOS; N(G)-monomethyl-l-arginine), soluble guanylyl cyclase [1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ)], and sarcolemmal and mitochondrial K(ATP) channels [glibenclamide, 5-hydroxydecanoic acid, and sodium (5-(2-(5-chloro-2-methoxybenzamido)ethyl)-2-methoxyphenylsulfonyl) (methylcarbamothioyl)amide (HMR 1098)]. Parstatin(1-26) cardioprotection was also abolished by atractyloside, a mitochondrial permeability transition pore (mPTP) opener. The inhibitors and opener alone had no effect on infarct size. Furthermore, preischemic treatment with parstatin(1-26) increased Akt and endothelial NOS phosphorylation at the time of reperfusion. After a 120-min reperfusion, parstatin(1-26) increased nitric oxide levels (12 +/- 0.4 to 17 +/- 0.9 mmol/g tissue) and cyclic GMP levels (87 +/- 21 to 395 +/- 36 pmol/g tissue). Parstatin(1-26) treatment either before or after ischemia results in an extremely efficacious protection against ischemia-reperfusion injury that depends on a G(i) protein-mediated pathway involving mPTP, the end effector of the preconditioning pathway. This suggests that parstatin(1-26) has a potential therapeutic role in the treatment of ischemia and reperfusion injury.
凝血酶从蛋白酶激活受体 1 切割得到的 N 端 41 个氨基酸肽段 parstatin，可保护大鼠心肌免受缺血再灌注损伤。本研究中，我们发现蛋白酶激活受体 1 的假定信号肽片段 1-26 包含 parstatin 的功能域。我们在大鼠心肌局部缺血再灌注损伤模型（n = 6/组）中评估了合成的 parstatin(1-26)肽。对照组大鼠心脏的梗死面积为 58 ± 1%危险区。parstatin(1-26)在再灌注前或再灌注后给药可将梗死面积减少至 13 ± 1%（P < 0.001）和 22 ± 1%危险区（P < 0.01）。G(i)蛋白（百日咳毒素）、磷酸肌醇 3-激酶/Akt（wortmannin）、一氧化氮合酶（NOS；N(G)-单甲基-l-精氨酸）、可溶性鸟苷酸环化酶[1H-[1,2,4]恶二唑[4,3-a]喹喔啉-1-酮（ODQ）]、肌浆网和线粒体 K(ATP)通道[格列本脲、5-羟基癸酸和钠（5-（2-（5-氯-2-甲氧基苯甲酰胺基）乙基）-2-甲氧基苯磺酰基）（甲基氨基甲酰基硫代）酰胺（HMR 1098] 的抑制剂均可消除 parstatin(1-26)的心脏保护作用。线粒体通透性转换孔（mPTP）开放剂 atractyloside 也可消除 parstatin(1-26)的心脏保护作用。这些抑制剂和开放剂单独使用对梗死面积无影响。此外，缺血预处理用 parstatin(1-26)在再灌注时增加 Akt 和内皮型一氧化氮合酶磷酸化。再灌注 120 分钟后，parstatin(1-26)增加一氧化氮水平（12 ± 0.4 至 17 ± 0.9 mmol/g 组织）和环鸟苷酸水平（87 ± 21 至 395 ± 36 pmol/g 组织）。parstatin(1-26)在缺血前或缺血后处理均可产生非常有效的缺血再灌注损伤保护作用，这依赖于一种 G(i)蛋白介导的途径，该途径涉及 mPTP，即预处理途径的终末效应物。这表明 parstatin(1-26)在缺血和再灌注损伤的治疗中有潜在的治疗作用。
