TXNIP介导的NLRP3炎症小体激活在心肌微血管内皮细胞缺氧/复氧损伤中的作用

目的 研究硫氧还蛋白结合蛋白（TXNIP）介导的NLRP3炎症小体激活在心肌微血管内皮细胞（CMECs）缺氧/复氧（H/R）损伤中的作用。方法 分离培养C57BL/6J小鼠CMECs,随机分为对照组、H/R损伤组、H/R+Scrambled siRNA组和H/R+TXNIP siRNA组。各组处理后使用ELISA试剂盒检测细胞IL-1β水平,采用免疫共沉淀的方法检测TXNIP和NLRP3的相互作用,Western blot检测TXNIP和NLRP3的表达水平,乳酸脱氢酶试剂盒检测细胞培养上清LDH释放情况和细胞Caspase-3活性。结果 与对照组相比,H/R后CMECs的NLRP3表达水平明显升高（P<0.05）,NLRP3炎症小体激活（IL-1β水平升高,P<0.01）,且TXNIP和NLRP3的结合效果明显增强（P<0.01）。运用TXNIP siRNA抑制TXNIP表达后行H/R处理,与H/R+Scrambled siRNA组相比,NLRP3炎症小体激活水平明显下降（IL-1β水平降低）,细胞Caspase-3活力和LDH释放水平均显著降低（均P<0.05）。结论 在CMECs发生H/R损伤时,NLRP3炎症小体激活,TXNIP和NLRP3的相互作用增强;抑制TXNIP表达后,NLRP3炎症小体激活水平降低,内皮损伤减轻。说明TXNIP介导的NLRP3炎症小体激活参与CMECs的H/R损伤,可能成为CMECs的H/R损伤的新机制。     

NLRP3炎性体加重小鼠脑缺血再灌注损伤的机制探讨

目的：探讨Nod样受体蛋白3（NLRP3）炎性体（NLRP3蛋白、IL-1β、IL-8）在小鼠脑缺血再灌注损伤中的作用和机制。方法将C57BL／6小鼠随机分为对照组和格列本脲（ NLRP3抑制剂）组各20只,每组中一半小鼠通过大脑中动脉栓塞法构建缺血再灌注（ IR）模型,其余接受假手术处理。格列本脲组术前30 min腹腔注射500 mg／kg格列本脲。造模成功后对小鼠进行神经学评分,2,3,5,-氯化三苯基四氮唑染色,并计算缺血梗死面积,HE染色观察病理变化,TUNEL染色观察各组神经元凋亡情况,Western Blot检测小鼠脑组织NLRP3蛋白表达,ELISA检测小鼠脑组织中IL-1β、IL-18浓度。结果各组IR小鼠脑损伤程度均重于假手术小鼠,但是对照组IR小鼠脑损伤程度比格列本脲组严重。 HE染色和TUNEL染色显示,IR小鼠脑组织出现明显损伤,神经元凋亡数量明显增多,格列本脲可减轻IR造成的病理损伤程度。与对照组相比,格列本脲组的脑组织NLRP3蛋白表达及IL-1β、IL-18升高程度明显降低（ P均＜0．05）。结论 NLRP3炎性体可促进小鼠脑IR损伤,主要通过增加细胞因子释放和促进神经元凋亡实现的。     

心肌缺血/再灌损伤时TXNIP表达水平升高并增加心肌自噬

目的 探讨心肌缺血/再灌注（MI/R）时硫氧还蛋白相互结合蛋白（TXNIP）表达及对心肌细胞自噬水平的影响。 方法 构建TXNIP敲除鼠及TXNIP过表达小鼠,制作上述小鼠MI/R模型,观察MI/R后心肌TXNIP表达水平是否与心肌损伤及自噬有关。 结果 与假手术组（Sham）小鼠相比,小鼠心肌TXNIP表达水平在缺血及再灌注损伤过程中持续升高（P<0.01）。在小鼠MI/R后,心脏超声证实与野生型（WT）小鼠相比,TXNIP过表达小鼠LVEF（%）值更低（P<0.05）;伊文氏蓝/TTC染色同样证实TXNIP过表达小鼠心肌梗死面积更大（P<0.05）。而TXNIP敲除鼠MI/R后心脏LVEF（%）值（P<0.05）及心肌梗死面积（P<0.05）均较WT小鼠显著减轻。通过免疫印迹（LC3Ⅱ/LC3I及P62表达）及电子显微镜观察自噬小体检测发现,相比WT小鼠,TXNIP敲除小鼠心肌自噬程度更轻（P<0.05）,TXNIP过表达小鼠则心肌自噬程度更重（P<0.05）。 结论 上述结果证实了在MI/R后TXNIP升高导致心脏功能的降低,心肌梗死面积的增加及心肌细胞自噬的增多。     

红景天苷抑制缺血/再灌注诱导的心肌微血管内皮细胞凋亡

目的探讨红景天苷对大鼠心肌微血管内皮细胞(CMECs)缺血/再灌注损伤的影响及其可能的机制。方法分离培养大鼠CMECs,建立模拟缺血/再灌注模型,分为对照组、模拟缺血/再灌注(SI/R)组、SI/R+红景天苷组(1.0、2.5、5.0、10.0μmol/L)组。待红景天苷最适浓度确认为5μmol/L后,增加SI/R+红景天苷+LY[磷酯酰肌醇3激酶(PI3k)特异性抑制剂LY294002]组。MTT法检测细胞增殖能力,细胞划痕实验检测细胞迁移能力,TUNEL法检测细胞凋亡,采用Western blot检测Akt磷酸化水平,以及凋亡抑制蛋白生存素和Bcl-2的表达。结果与对照组相比较,SI/R组CMECs增殖能力明显降低(0.410±0.011比0.200±0.014,P=0.041),凋亡率显著上升(4.15%±0.12%比26.05%±0.97%,P=0.018),而与SI/R组相比,SI/R+红景天苷组(1.0、2.5、5.0、10.0μmol/L)细胞增殖能力明显升高并呈剂量依赖性,细胞迁移率,而凋亡率则明显下降(均为P<0.05),LY294002组凋亡指数与SI/R+红景天苷组相比显著提高(22.03%±0.98%比16.28%±1.40%,P=0.029)。与SI/R组相比较,红景天苷可显著上调Akt的磷酸化,以及上调抗凋亡蛋白生存素和Bcl-2的表达(均为P<0.05),而此作用可被LY294002显著抑制(均为P<0.05)。结论红景天苷可显著抑制缺血/再灌注损伤诱导的CMECs凋亡,促进细胞存活,改善细胞功能,其作用机制可能与激活PI3K/Akt,以及上调凋亡抑制蛋白生存素和Bcl-2表达相关。     

Inflammasome activation of cardiac fibroblasts is essential for myocardial ischemia/reperfusion injury

Background- Inflammation plays a key role in the pathophysiology of myocardial ischemia/reperfusion (I/R) injury; however, the mechanism by which myocardial I/R induces inflammation remains unclear. Recent evidence indicates that a sterile inflammatory response triggered by tissue damage is mediated through a multiple-protein complex called the inflammasome. Therefore, we hypothesized that the inflammasome is an initial sensor for danger signal(s) in myocardial I/R injury. Methods and Results- We demonstrate that inflammasome activation in cardiac fibroblasts, but not in cardiomyocytes, is crucially involved in the initial inflammatory response after myocardial I/R injury. We found that inflammasomes are formed by I/R and that its subsequent activation of inflammasomes leads to interleukin-1β production, resulting in inflammatory responses such as inflammatory cell infiltration and cytokine expression in the heart. In mice deficient for apoptosis-associated speck-like adaptor protein and caspase-1, these inflammatory responses and subsequent injuries, including infarct development and myocardial fibrosis and dysfunction, were markedly diminished. Bone marrow transplantation experiments with apoptosis-associated speck-like adaptor protein-deficient mice revealed that inflammasome activation in bone marrow cells and myocardial resident cells such as cardiomyocytes or cardiac fibroblasts plays an important role in myocardial I/R injury. In vitro experiments revealed that hypoxia/reoxygenation stimulated inflammasome activation in cardiac fibroblasts, but not in cardiomyocytes, and that hypoxia/reoxygenation-induced activation was mediated through reactive oxygen species production and potassium efflux. Conclusions- Our results demonstrate the molecular basis for the initial inflammatory response after I/R and suggest that the inflammasome is a potential novel therapeutic target for preventing myocardial I/R injury.     

Protein kinase activation and myocardial ischemia/reperfusion injury

Myocardial ischemia and ischemia/reperfusion activate several protein kinase pathways. Protein kinase activation potentially regulates the onset of myocardial cell injury and the reduction of this injury by ischemic and pharmacologic preconditioning. The primary protein kinase pathways that are potentially activated by myocardial ischemia/reperfusion include: the MAP kinases, ERK 1/2, JNK 1/2, p38 MAPKalpha/beta; the cell survival kinase, Akt; and the sodium-hydrogen exchanger (NHE) kinase, p90RSK. The literature does not support a role for ischemia/reperfusion in the activation of the tyrosine kinases, Src and Lck, or the translocation and activation of PKC. This review will detail the role of these protein kinases in the onset of myocardial cell death by necrosis and apoptosis and the reduction of this injury by preconditioning.     

冠状动脉微血管内皮细胞释放的神经调节蛋白-1对缺血/再灌注心肌的作用及其机制探讨

目的探讨大鼠缺血/再灌注损伤(I/RI)时,神经调节蛋白-1(NRG-1)在冠状动脉微血管内皮细胞(CMECs)-心肌细胞共培养中的作用及其机制。方法分离培养大鼠CMECs和心肌细胞,建立CMECs-心肌细胞共培养(Coculture)模型和体外模拟缺血/再灌注(SI/R)模型,收集CMECs培养上清。MTT法检测心肌细胞活性,TUNEL法检测心肌细胞凋亡指数,Western blot法检测CMECs培养上清中NRG-1表达、心肌细胞p Erb B2、p ERK基因和环氧化酶-2(COX-2)水平,含半胱氨酸的天冬氨酸蛋白水解酶-3(caspase-3)酶活性反应心肌细胞凋亡。结果在心肌细胞中,与对照组相比,SI/R(4 h/4 h)组细胞活性明显降低(P<0.01),SI/R+Coculture组细胞活性升高(P=0.02)。CMECs在SI/R 4 h/4 h时,NRG-1的分泌较对照组增加最明显(P<0.01)。心肌细胞SI/R组凋亡指数和Caspase-3酶活性比对照组明显升高(27.97±0.90比3.58±0.23,P<0.01;375.93±11.76比100.00±0.00,P<0.01)。共培养或NRG-1处理细胞后,凋亡指数和Caspase-3酶活性较SI/R组降低(16.82±1.03比27.97±0.90,P<0.01;166.16±15.15比375.93±11.76,P<0.01),且Erb B2和ERK磷酸化水平以及COX-2表达明显增加(均为P<0.01)。用Erb B2或ERK1/2抑制剂预处理心肌细胞后,共培养和NRG-1的作用消失(均为P<0.01)。结论在I/RI过程中,CMECs释放NRG-1,抑制I/RI诱导的心肌细胞凋亡,其保护作用与增加Erb B2、ERK磷酸化和COX-2表达可能有关。     

NLRP3炎性体在心肌梗死后心室重塑中的作用

NLRP3炎性体是一种细胞内多蛋白复合物,是无菌性炎症反应的关键介质,在心肌梗死（myocardial Infarction,MI）的病理生理机制中发挥重要作用。NLRP3炎性体可调节半胱氨酸蛋白酶（caspase-1）的激活,促进IL-1β等炎症因子产生,参与细胞程序性死亡。大量研究表明,抑制NLRP3炎性体可有效减轻MI后炎症反应,从而改善MI后心功能不全及心室重塑。因此,NLRP3炎性体可能是减少MI后心血管事件的发生及改善预后新的治疗靶点,本文就NLRP3炎性体在MI后心室重塑中的作用进行综述。     

CD137 signaling aggravates myocardial ischemia-reperfusion injury by inhibiting mitophagy mediated NLRP3 inflammasome activation

BACKGROUND The inflammatory response caused by the NLRP3 is closely related to the formation of myocardial ischemiareperfusion injury. Costimulatory receptor CD137 and its ligand play a crucial role in regulating the inflammatory immune response in atherosclerosis, which is the fundamental cause of cardiovascular diseases. However, the roles of CD137 signaling in the process of myocardial ischaemia-reperfusion(IR) injury remain unknown.METHODS Genetic ablation was used to determine the functiona...     

PI3K/Akt信号参与介导虎杖甙对缺血/再灌注心肌的保护作用

目的 探讨虎杖甙对小鼠心肌缺血/再灌注损伤的影响及可能机制。方法 建立小鼠缺血/再灌注损伤模型,随机将小鼠分为5组（每组18只）：假手术组（Sham）、缺血/再灌注组（I/R）、缺血/再灌注+虎杖甙组（I/R+PD）、缺血/再灌注+虎杖甙+LY294002组（I/R+PD+LY294002）和缺血/再灌注+LY294002组（I/R+LY294002）。小鼠心脏超声检测心功能;Masson染色评估胶原容积分数（CVF);TTC染色测定小鼠心肌梗死面积;ELISA法检测血浆CK和LDH水平;Tunel法测定小鼠心肌细胞凋亡,Western blot检测p-Akt的表达。结果 与Sham组相比,I/R组LVEF和LVFS值均显著降低（P<0.05）,心肌梗死面积、血浆CK和LDH水平均显著增加（P<0.05）,心肌细胞凋亡显著增加（P<0.05）,心肌CVF值显著增加（P<0.05）,心肌p-Akt蛋白表达显著增加（P<0.05）;与I/R组相比,I/R+PD组LVEF和LVFS值均显著增加（P<0.05）,心肌梗死面积、血浆CK和LDH水平均显著降低（...     

Different signaling pathways induce apoptosis in endothelial cells and cardiac myocytes during ischemia/reperfusion injury

Apoptosis contributes, with necrosis, to the cardiac cell loss after ischemia/reperfusion injury. The apoptotic cascade is initiated either by mitochondrial damage and activation of caspase-9 or by death receptor ligation and activation of caspase-8. In the present study, performed in the isolated rat heart exposed either to ischemia alone or ischemia followed by reperfusion, cleavage of caspase-9 was observed primarily in endothelial cells. Conversely, caspase-8 cleavage was only found in cardiomyocytes, where it progressively increased throughout reperfusion. Addition of a specific caspase-9 inhibitor to the perfusate before ischemia prevented endothelial apoptosis, whereas preischemic infusion of a specific caspase-8 inhibitor affected only myocyte apoptosis. Additionally, caspase-8-mediated BID processing was observed only during reperfusion. Production of tBID then sustains mitochondrial injury and perpetuates caspase-9 activation.     

他汀类药物抑制心肌缺血-再灌注炎症损伤的机制

近年研究表明,炎症反应在心肌缺血-再灌注损伤(myocardial ischemia-reperfusion injury,MIRI)中占有重要地位,炎症反应与MIRI之间有着密切关系.实验证实,他汀类药物除具有降血脂的作用以外,还有心肌保护效应.本文主要从他汀类药物抑制中性粒细胞介导的心肌损伤、磷脂酰肌醇(-3)激酶(phosphatidyl inositol 3-kinase,PI3K)/蛋白激酶B(protein kinase B,Akt)/内皮型一氧化氮合酶信号通路两个方面阐述在心肌缺血-再灌注过程中,他汀类药物抑制心肌炎症损伤的主要机制.     

Histamine H2 receptor activation exacerbates myocardial ischemia/reperfusion injury by disturbing mitochondrial and endothelial function

There is evidence that H2R blockade improves ischemia/reperfusion (I/R) injury, but the underlying cellular mechanisms remain unclear. Histamine is known to increase vascular permeability and induce apoptosis, and these effects are closely associated with endothelial and mitochondrial dysfunction, respectively. Here, we investigated whether activation of the histamine H2 receptor (H2R) exacerbates myocardial I/R injury by increasing mitochondrial and endothelial permeability. Serum histamine levels were measured in patients with coronary heart disease, while the influence of H2R activation was assessed on mitochondrial and endothelial function in cultured cardiomyocytes or vascular endothelial cells, and myocardial I/R injury in mice. The serum histamine level was more than twofold higher in patients with acute myocardial infarction than in patients with angina or healthy controls. In neonatal rat cardiomyocytes, histamine dose-dependently reduced viability and induced apoptosis. Mitochondrial permeability and the levels of p-ERK1/2, Bax, p-DAPK2, and caspase 3 were increased by H2R agonists. In cultured human umbilical vein endothelial cells (HUVECs), H2R activation increased p-ERK1/2 and p-moesin levels and also enhanced permeability of HUVEC monolayer. All of these effects were abolished by the H2R blocker famotidine or the ERK inhibitor U0126. After I/R injury or permanent ischemia, the infarct size was reduced by famotidine and increased by an H2R agonist in wild-type mice. In H2R KO mice, the infarct size was smaller; myocardial p-ERK1/2, p-DAPK2, and mitochondrial Bax were downregulated. These findings indicate that H2R activation exaggerates myocardial I/R injury by promoting myocardial mitochondrial dysfunction and by increasing cardiac vascular endothelial permeability.     

Nitric oxide in myocardial ischemia/reperfusion injury

Administration of nitric oxide (NO), NO donors or drugs that enhance NO release (statins, calcium antagonists, ACE-inhibitors, dexamethasone) prior to ischemia protects the myocardium against ischemia/reperfusion injury. While this exogenous administration of NO prior to ischemia can initiate a preconditioning-like phenomenon, endogenous NO-synthase (NOS)-derived NO is not involved in triggering or mediating the early phase of ischemic preconditioning's protection, but does play a pivotal role for initiating and mediating the delayed phase of ischemic preconditioning's protection. The present review now summarizes the importance of endogenous and exogenous NO when given at the time of reperfusion for vascular and myocardial function and morphological outcome following ischemia/reperfusion. Given the inconsistency of the published data, potential confounding factors that might affect experimental results on the role of NO in myocardial ischemia/reperfusion were identified, such as (1) the lack of characterization of the involved NOS isoforms in myocardial ischemia/reperfusion injury in different animal species, (2) the lack of direct measurements of myocardial NO concentration and/or NOS activity to assure sufficient NOS inhibition, (3) the lack of consideration of nonenzymatic NO production as a potential source of NO, and (4) the absence of plasma or blood components in in vitro studies influencing NO delivery and metabolism. Future research on the importance of NO in ischemia/reperfusion injury will have to focus more precisely on the identification and standardization of potential confounding experimental factors that influence synthesis, transport, and interaction of NO with various targets in blood and tissue.     

微小RNA在心肌缺血再灌注损伤中的作用及机制

微小RNA（microRNA,miRNA）是一类在进化上高度保守的小分子非编码RNA,大约南19～25个核苷酸组成,具有转录后渊控蛋白质编码基因表达的功能,     

T细胞参与心肌I/R损伤的研究进展

心肌I/R损伤（MI/RI）是治疗心肌梗死过程中的并发症之一,中性粒细胞、巨噬细胞等固有免疫细胞引起的炎性反应是导致MI/RI的重要原因。众多免疫细胞如何在MI/RI中发挥作用是目前研究的热点问题。近年来,越来越多的研究表明T细胞在MI/RI中发挥重要作用。本文将阐述T细胞在MI/RI中的作用及机制的研究进展,并分析目前存在的问题及发展方向。     

氧化应激在糖尿病所致的心肌缺血/再灌注损伤中的作用

近年来,糖尿病（DM）患病率与日俱增,且并发症多。当DM患者伴发缺血性心肌病（IHD）时极易诱发心肌缺血/再灌注损伤（MI/RI）,而氧化应激在MI/RI中发挥着关键作用。由于胰岛素抵抗诱发的脂质代谢紊乱、内皮细胞功能障碍以及脂联素抵抗会导致心肌细胞凋亡增多、细胞抗氧化防御系统减弱以及促存活细胞信号通路受损,致使糖尿病性心脏病患者更易发生MI/RI,最终导致心力衰竭。氧化应激的3个主要机制分别是:活性氧簇（ROS）和活性氮簇(RNS)以及解偶联的一氧化氮合酶（NOS）通过氧化/硝化反应干扰线粒体质量调控系统,在这篇综述中,我们将主要对氧化应激在DM发生的MI/RI中可能存在的作用机制进行探讨。     

人参二醇组皂甙对实验犬心肌缺血再灌注损伤保护作用的研究

结扎犬左冠脉前降支９０ｍｉｎ，恢复再灌注２４０ｍｉｎ。将犬随机分为治疗组及对照组。缺血即刻、治疗组静点人参二醇组皂甙（ＰＤＳ）２５ｍｇ／ｋｇ，以生理盐水１００ｍｌ稀释，对照组静点生理盐水１００ｍｌ。观察血清肌酸磷酸激酶（ＣＰＫ）、血清过氧化脂质（ＬＰＯ）及心肌超氧化物歧化酶（ＳＯＤ）活力和ＬＰＯ含量的变化。结果表明，治疗组在缺血９０ｍｉｎ、再灌注１２０ｍｉｎ、２４０ｍｉｎ、血清ＣＰＫ值显著低于对照组（Ｐ＜０．０５），于再灌注２４０ｍｉｎ、血清及心肌ＬＰＯ含量显著低于对照组（Ｐ＜０．０５），心肌ＳＯＤ活力显著高于对照组（Ｐ＜０．０５）。提示ＰＤＳ对犬在体缺血再灌注损伤心脏具有保护作用，认为可能是通过提高心肌组织ＳＯＤ活力，加强氧自由基清除，减轻了细胞损伤。     

lncRNA减轻心肌缺血再灌注损伤的研究进展

长链非编码RNA(lncRNA)是一类长度大于200个核苷酸且无蛋白质编码能力的RNA,但在增殖、凋亡、迁移、侵袭和分化等多种生物过程中起着非常重要的调节作用。研究发现lncRNA与心肌缺血再灌注(I/R)损伤的发生发展密切相关。本综述讨论了lncRNA减少心肌I/R损伤及其可能机制的研究进展。