胱天蛋白酶募集域蛋白9介导心肌缺血再灌注损伤发生发展的机制研究进展

及时血运重建恢复冠状动脉血流是心肌梗死患者治疗的关键，但再灌注同时可能对缺血心肌造成二次损伤，即心肌缺血再灌注损伤。胱天蛋白酶募集域蛋白9(CARD9)是主要在骨髓细胞表达的重要衔接蛋白，在心肌缺血再灌注损伤中能够介导心肌细胞炎症反应、凋亡及自噬，可在炎症及免疫反应中充当调节器，从而参与心肌缺血再灌注损伤的发生发展。深入了解CARD9介导心肌缺血再灌注损伤的相关机制，或可为心肌缺血再灌注损伤的治疗提供新思路。     

卡维地洛在心肌缺血再灌注损伤中的作用

卡维地洛是第三代肾上腺素β受体阻滞剂，具有非选择性β受体阻滞和选择性α1受体阻滞活性。在防治心肌缺血再灌注损伤，促进心肌细胞存活方面具有重要作用。本文就卡维地洛在心肌缺血再灌注损伤防治中的肾上腺受体阻滞、抗氧化和自由基清除、心肌保护等主要作用作一综述。     

Apelin/APJ信号在心血管系统的生理和病理生理作用

Apelin是G蛋白耦联受体APJ的内源性配体,在心血管系统高度表达。Apelin/APJ信号具有增强心肌收缩力、降低血压、促进新生血管形成、保护心肌缺血及再灌注损伤、调控脂肪-胰岛素轴等作用。在治疗心力衰竭、高血压、缺血性心血管疾病、心肌缺血-再灌注损伤等方面具有很大潜力。     

Apelin／APJ信号在心血管系统的生理和病理生理作用

Apelin是G蛋白耦联受体APJ的内源性配体,在心血管系统高度表达.Apelin/APJ信号具有增强心肌收缩力、降低血压、促进新生血管形成、保护心肌缺血及再灌注损伤、调控脂肪-胰岛素轴等作用.在治疗心力衰竭、高血压、缺血性心血管疾病、心肌缺血-再灌注损伤等方面具有很大潜力.     

大鼠心肌缺血/再灌注损伤心肌细胞凋亡与Fas、FasL基因表达的变化

目的：探讨大鼠实验性心肌缺血再灌注时心肌细胞凋亡与Fas及Fas蛋白配体（Fas Ligand,FasL）基因表达的变化及与心肌组织损伤的关系。方法：以穿线结扎或松扎左冠状动脉制备大鼠心肌缺血再灌注模型。64只大鼠随机分成假手术组（假手术24h）、缺血再灌注I组（缺血30min、再灌注24h）、缺血再灌注Ⅱ组（缺备30min、再灌注72h）及缺血再灌注Ⅲ组（缺血3h、再灌注24h）。以缺口末端标记法检测心肌细胞凋亡的变化,S－P免疫组化法分别检测Fas与FasL蛋白水平变化,采用逆转录聚合酶链反应法检测Fas基因mRNA的表达改变,并分析心肌组织病理学损伤程度。结果：心肌缺血再灌注后心肌细胞凋亡指数Fas蛋白阳性染色指数与炎性细胞FasL蛋白阳性染色指数均增加,且均随缺血或再灌注时间延长而进一步增高; Fas基因的mRNA表达也上调,但以再灌注24h时达高峰;心肌缺血再灌注后心肌组织呈大小不一的灶性坏死,坏死周围有爆炸性一细胞浸润。结论：心肌缺血再灌注时心肌细胞凋亡、Fas基因的蛋白与mRNA表达水平及炎性细胞的FasL蛋白表达量均增加,心肌细胞凋亡与Fas/FasL系统参与了心肌缺血再灌注损伤过程。     

心肌缺血预适应状态下肌浆网功能变化的研究进展

心肌缺血预适应(IPC)是对抗心肌缺血再灌注损伤的一种内源性保护途径。近年 来研究表明,心肌肌浆网可能是IPC发挥心肌保护作用的重要靶点之一,IPC通过对肌浆 网上的钙转运蛋白功能的调节,延缓了缺血再灌注损伤导致的细胞内钙超载的发生。而 IPC可能是通过钙/钙调素依赖性蛋白激酶 Ⅱ、腺苷受体以及蛋白激酶C等途径作用于肌 浆网。     

单核细胞趋化蛋白-1与心肌缺血再灌注损伤的关系

心肌缺血/再灌注损伤是一个重要的临床问题,而临床上对心肌缺血/再灌注损伤的防治尚缺乏有效的方法.近年发现单核细胞趋化蛋白-1在心肌缺血再灌注的早期出现并呈动态变化,抑制其出现和发展会影响心肌缺血再灌注动物的表现和预后.对单核细胞趋化蛋白-1进行干预可能成为未来新的治疗方向.     

卡维地洛在心肌缺血再灌注损伤中的作用

卡维地洛是第三代肾上腺素β受体阻滞剂,具有非选择性β受体阻滞和选择性α1受体阻滞活性.在防治心肌缺血再灌注损伤,促进心肌细胞存活方面具有重要作用.本文就卡维地洛在心肌缺血再灌注损伤防治中的肾上腺受体阻滞、抗氧化和自由基清除、心肌保护等主要作用作一综述.     

热休克蛋白在心肌缺血再灌注损伤中的保护作用

热休克蛋白是细胞受应激原刺激后诱导产牛的、有利于增强机体抵御恶劣环境的一组应激蛋白,心肌缺血再灌注可诱导生成热休克蛋自,并使之随心肌损伤的加重而增多,对心肌缺血冉灌注所致的损伤起到保护作用。热休克蛋白具有保护缺血心脏,减轻再灌注损害的作用,还可以作为监测指标,更好地估计心肌损伤程度,预测转归。本文通过阅读围内外文献对热休克蛋白在心肌缺血再灌注中的保护作用加以综述。     

Toll样受体参与心肌缺血再灌注损伤的研究进展

<正>再灌注治疗在急性心肌梗死患者中应用逐渐增多,其引发的再灌注损伤日益受到人们的重视,对其发生机制进行了积极的探索研究,近年来研究发现,固有免疫的成员之一Toll样受体在心肌缺血再灌注损伤的炎症反应中起了重要作用,本文就Toll受体在心肌缺血再灌注损伤中的作用及发生机制展开综述。1 TLRs概述Toll样受体家族(TLRs)是最早被人类认识的免疫细胞的模式识别受体(PRRS),TLRs最初发现是果     

Tissue factor deficiency and PAR-1 deficiency are protective against renal ischemia reperfusion injury

Ischemia/reperfusion (IR) injury is a leading cause of acute renal failure and an important contributor to allograft damage. Tissue factor (TF) is up-regulated during IR, and TF inhibition reduces renal injury. However, the underlying mechanisms by which TF contributes to injury have not been elucidated. We postulated that TF contributes to IR injury by production of coagulation proteases and subsequent signaling by protease activated receptor (PARs). We compared renal injury after 25 minutes of bilateral renal ischemia and varying periods of reperfusion in C57BL/6 mice, those expressing low levels of TF (low-TF), hirudin-treated C57BL/6, and mice lacking either PAR-1 or PAR-2. C57BL/6 mice developed severe renal failure and died within 48 hours of reperfusion. In contrast, low-TF, hirudin-treated C57BL/6, and PAR-1-/- mice were protected from renal failure and had reduced mortality, tubular injury, neutrophil accumulation, and lower levels of the chemokines KC and MIP-2. Importantly, PAR-1-/- mice had lower chemokine levels despite up-regulation of TF and fibrin deposition. In addition, treating PAR-1-/- mice with hirudin conferred no additional benefit. Somewhat surprisingly, PAR-2 deficiency did not protect from renal failure. These experiments indicate that increased TF activity after renal IR leads to increased CXC chemokine expression and subsequent neutrophil-mediated injury predominantly by thrombin-dependent PAR-1 signaling.     

蛋白酶激活受体2与心肌缺血/再灌注损伤

氧化应激、炎症和细胞凋亡在心肌缺血/再灌注损伤(myocardial ischemia/reperfusion injury,MI/RI)中起重要作用，而蛋白酶激活受体（protease-activated receptor，PAR）-2与MI/RI之间存在密切关系。PAR-2广泛分布于心血管系统，可被多种蛋白酶激活，启动多种生物学效应。本文从上述几方面对PAR-2与MI/RI的关系进行阐述，为MI/RI的防治提供理论依据。     

曲美他嗪对人再灌注损伤心肌蛋白酶活化受体-2表达的影响

目的:观察曲美他嗪口服预处理对再灌注损伤心肌蛋白酶活化受体-2(PAR-2)的表达影响,探讨其对心肌缺血再灌注损伤的保护作用。方法:将40例行体外循环二尖瓣瓣膜置换术患者随机分为曲美他嗪组和对照组,每组20例,曲美他嗪组术前予以曲美他嗪预处理2周(曲美他嗪片20mg/次,3次/d)。术中取开放升主动脉恢复心肌血供30min时的右房心肌,采用实时定量PCR检测心肌组织PAR-2的mRNA水平;免疫组织化学法检测心肌组织PAR-2的蛋白水平;在主动脉开放后30min、6h、24h经颈内中心静脉置管处取血,测定肌酸激酶同工酶(CK-MB)、肌钙蛋白I(cTnI)和肌红蛋白(MYO)的水平。结果:①与对照组比较,曲美他嗪组心肌组织PAR-2的mRNA及蛋白表达水平明显升高(P<0.05),CK-MB、cTnI、MYO的水平(主动脉开放后30min、6h)显著降低(P<0.05)。结论:曲美他嗪对心肌缺血再灌注损伤具有显著的保护作用,其机制可能与上调PAR-2的表达有关。     

蛋白酶激活受体-2对缺血再灌注大鼠心肌细胞凋亡的影响

目的 探讨蛋白酶激活受体2(PAR-2)对缺血再灌注大鼠心肌细胞凋亡的影响.方法 40只雄性SD大鼠随机分为5组:假手术组(sham组),缺血再灌注组(I/R组)和丝-亮-异亮-甘-精-亮-酰胺(SLIGRL-NH2)低剂量组(0.5 mg/kg)、中剂量组(1 mg/kg)、高剂茸组(3 mg/kg),每组8只,建立大鼠在体心肌缺血再灌注模型.采用末端标记法(TUNEL)和DNA琼脂糖凝胶电泳的方法检测心肌细胞凋亡,免疫组织化学法检测凋亡相关蛋白Bcl-2、Bax的表达,实时荧光定量PCR检测心肌细胞PAR-2mRNA的表达情况.结果 (1)SLIGRL-NH2中、高剂量组凋亡指数明显低于I/R组(SLIGRL-NH2中、高剂量组分别为23.36%±3.77%、15.56%±1.24%比I/R组35.19%±4.50%,P<0.05～0.01);凋亡相关蛋白Bcl-2高于I/R组(SLIGRL-NH2中、高剂量组分别为0.983±0.103、1.197±0.119比I/R组0.761±0.043,P<0.05～0.01);凋亡相关蛋白Bax的表达显著低于I/R组(SLIGRL-NH2中、高剂量组分别为0.646±0.041,0.578±0.029比I/R组0.759±0.035,P均<0.01);PAR-2mRNA的表达明显高于I/R组(SLIGRL-NH2中、高剂量组分别为3.73±0.45,7.62±0.81比I/R组1.42±0.41,P均<0.01).(2)DNA凝胶电泳结果显示,I/R组、SLIGRL-NH2低剂量组可见到DNA梯带,假手术组和SLIGRL-NH2中、高剂量组则无明显DNA梯带.结论 PAR-2激动剂SLIGRL-NH2可上调并激活PAR-2,并通过增加Bcl-2/Bax的比值抑制大鼠缺血再灌注心肌细胞的凋亡而发挥心肌保护效应,且该作用具有一定的剂量依赖效应.     

Protease-activated receptor-2 stimulates angiogenesis and accelerates hemodynamic recovery in a mouse model of hindlimb ischemia

Proteinase-activated receptors (PAR-2) are expressed by the cardiovascular system and mediate vasodilation, plasma protein extravasation, and endothelial cell proliferation, all regarded as essential steps for neovascularization. We investigated the angiogenic action of PAR-2 signaling in vivo. The effect of the PAR-2 activating peptide (PAR-2AP, SLIGRL-NH2) was assessed in the absence of ischemia, and the therapeutic potential of PAR-2AP and the PAR-2 agonist trypsin (at 300 and 1.5 nmol IM daily for 21 days, respectively) was also tested in mice subjected to unilateral limb ischemia. PAR-2AP increased capillarity in normoperfused adductor skeletal muscles, whereas neither the vehicle of the PAR2-AP nor the PAR-2 reverse peptide (PAR-2RP, LRGILS-NH2) did produce any effect. In addition, both PAR-2AP and trypsin enhanced reparative angiogenic response to limb ischemia, an effect that was not produced by PAR-2RP or the vehicle of PAR-2 agonists. Potentiation of reparative angiogenesis by PAR-2AP or trypsin resulted in an accelerated hemodynamic recovery and enhanced limb salvage. In conclusions, our study is the first to demonstrate the angiogenic potential of PAR-2 stimulation in vivo. If similar effects occur in humans, PAR-2AP agonists could have some therapeutic potential for the treatment of tissue ischemia.     

The two-receptor system PAR-1/PAR-4 mediates α-thrombin-induced [Ca2+]i mobilization in human astrocytoma cells

The proteinase-activated receptor 1 (PAR-1) was characterized as a functional receptor for thrombin in cells from different brain tumor entities. Whether PAR-1 alone accounts for thrombin-induced effects in human cancer cells, or whether other PAR contribute is unknown. We established primary cultures from two neurosurgically removed human astrocytomas and investigated intracellular signaling roles of PAR-1 and PAR-4 by estimating the effect of α-thrombin and PAR-activating peptides on [Ca²⁺]_i mobilization in single astrocytoma cells. α-Thrombin or the PAR-1-activating peptide SFLLRN induced a transient calcium mobilization. This suggests the involvement of PAR-1 in α-thrombin-induced calcium signaling in human astrocytoma cells. In addition, a second, PAR-4-dependent, mechanism exists. This was deduced from the findings that a further calcium signal could be observed in human astrocytoma cells stimulated with α-thrombin after SFLLRN and the PAR-4-activating peptide GYPGQV also induced a calcium response. In addition, the observation that trypsin, known to activate both PAR-2 and PAR-4, but not the specifically PAR-2-activating peptide SLIGRL induced calcium signaling is a further indication of functional PAR-4-type thrombin receptors in human astrocytoma cells. This is the first report demonstrating a signaling role for a dual thrombin receptor system in human tumor cells. Received: 28 July 1999 / Accepted: 23 September 1999     

Protease-activated receptor-2 modulates myocardial ischemia-reperfusion injury in the rat heart

Protease-activated receptor-2 (PAR-2) is a member of seven transmembrane domain G protein-coupled receptors activated by proteolytic cleavage whose better known member is the thrombin receptor. The pathophysiological role of PAR-2 remains poorly understood. Because PAR-2 is involved in inflammatory and injury response events, we investigated the role of PAR-2 in experimental myocardial ischemia-reperfusion injury. We show for the first time that PAR-2 activation protects against reperfusion-injury. After PAR-2-activating peptide (2AP) infusion, we found a significant recovery of myocardial function and decrease in oxidation at reflow. Indeed, the glutathione cycle (glutathione and oxidized glutathione) and lipid peroxidation analysis showed a reduced oxidative reperfusion-injury. Moreover, ischemic risk zone and creatine kinase release were decreased after PAR-2AP treatment. These events were coupled to elevation of PAR-2 and tumor necrosis factor alpha (TNFalpha) expression in both nuclear extracts and whole heart homogenates. The recovery of coronary flow was not reverted by L-nitroarginine methylester, indicating a NO-independent pathway for this effect. Genistein, a tyrosine kinase inhibitor, did not revert the PAR-2AP effect. During early reperfusion injury in vivo not only oxygen radicals are produced but also numerous proinflammatory mediators promoting neutrophil and monocyte targeting. In this context, we show that TNFalpha and PAR-2 are involved in signaling in pathophysiological conditions, such as myocardial ischemia-reperfusion. At the same time, because TNFalpha may exert pro-inflammatory actions and PAR-2 may constitute one of the first protective mechanisms that signals a primary inflammatory response, our data support the concept that this network may regulate body responses to tissue injury.     

钙敏感受体与缺血/再灌注损伤诱发心肌细胞凋亡的线粒体途径的关系

目的探讨钙敏感受体（CaR）参与心肌缺血／再灌注损伤诱发细胞凋亡的机制。方法Langendorff离体灌流的方法复制心脏缺血／再灌注模型。观察缺血／再灌注和加入CaR激动剂时CaR的表达情况。TUNEL染色观察不同组别细胞凋亡,应用激光扫描共聚焦显微镜观察大鼠心肌细胞的线粒体膜电位的变化。Western blot检测心肌组织线粒体中细胞色素C及Bcl-2的表达。结果心肌缺血／再灌注和加入CaR激动剂时CaR的表达明显高于对照组（P均〈0．01）。TUNEL染色发现缺血／再灌注组和激动剂组细胞凋亡率明显增加（P均〈0．05）,同时此两组的线粒体膜电位下降明显（P均〈0．05）,线粒体细胞色素C与Bcl-2的表达也明显下降（P均〈0．05）。结论CaR激活在缺血／再灌注时通过诱发线粒体损伤,促进细胞凋亡。     

Role of cardiac ATP-sensitive K+ channels induced by angiotensin II type 1 receptor antagonist on metabolism, contraction and relaxation in ischemia-reperfused rabbit heart

The role of cardiac adenosine triphosphate-sensitive K+ (K(ATP)) channels induced by angiotensin II type 1 (AT1) receptor antagonist, CV-11974, on myocardial metabolism and contraction during ischemia, and reperfusion by the phosphorus 31-nuclear magnetic resonance in Langendorff-perfused rabbit hearts was investigated. After 20 min of continuous normothermic global ischemia, 30 min of postischemic reperfusion was carried out. CV-11974 with or without the K(ATP) channel blocker, glibenclamide, or the bradykinin B2 receptor antagonist, D-Arg-[Hyp3,D-Phe7]bradykinin, was administered 40 min prior to the global ischemia. Adenosine triphosphate (ATP), creatine phosphate (PCr), inorganic phosphate (Pi), intracellular pH (pHi), left ventricular systolic developed pressure, left ventricular end-diastolic pressure (LVEDP), and coronary flow were measured. Twenty-eight hearts were divided into 4 experimental groups consisting of 7 hearts each. Group I consisted of controls, Group II perfused with CV-11974 (10(-6) mol/L), Group III perfused with CV-11974 (10(-6) mol/L) in combination with glibenclamide (10(-6) mol/L), and Group IV perfused with CV-11974 (10(-6) mol/L) in combination with D-Arg-[Hyp3,D-Phe7]bradykinin (10(-6) mol/L). Group II showed a significant inhibition of the decrease in ATP during ischemia and reperfusion compared with Group I (p<0.01), being 42+/-3% and 19+/-4% at ischemia, 69+/-3% and 47+/-4% at reperfusion in Group II and Group I, respectively. Group II also showed a significant inhibition of the increase in LVEDP during ischemia and reperfusion compared with Group I (p<0.01), being 13+/-4 mmHg and 52+/-8 mmHg at ischemia, 8+/-2 mmHg and 26+/-5 mmHg at reperfusion in Group II and Group I, respectively. However, Group II did not inhibit the decrease in ATP and the increase in LVEDP during ischemia and reperfusion. Group IV also showed no inhibition of the aforementioned parameters during the same period. These results suggest that CV-11974 has a significant beneficial effect for improving myocardial energy metabolism and relaxation during both myocardial ischemia and reperfusion, which is provided by K(ATP) channels and bradykinin B2 receptor. The cardioprotective quality of the AT1 receptor antagonist is caused by the K(ATP) channels that are mediated by the bradykinin B2 receptor.