Flow cytometric analysis of circulating microvesicles derived from myocardial ischemic preconditioning and cardioprotection of ischemia/reperfusion injury in rats

Objective: To establish a flow cytometric method to detect the alteration of phenotypes and concentration of circulating microvesicles(MVs) from myocardial ischemic preconditioning(IPC) treated rats(IPC-MVs), and to investigate the effects of IPC-MVs on ischemia/reperfusion(I/R) injury in rats. Methods: Myocardial IPC was elicited by three cycles of 5-min ischemia and 5-min reperfusion of the left anterior descending(LAD) coronary artery. Platelet-free plasma(PFP) was isolated through two steps of centrifugation at room temperature from the peripheral blood, and IPC-MVs were isolated by ultracentrifugation from PFP. PFP was incubated with anti-CD61, anti-CD144, anti-CD45 and anti-Erythroid Cells, and added 1, 2 μm latex beads to calibrate and absolutely count by flow cytometry. For functional research, I/R injury was induced by 30-min ischemia and 120-min reperfusion of LAD. IPC-MVs 7 mg/kg were infused via the femoral vein in myocardial I/R injured rats. Mean arterial blood pressure(MAP), heart rate(HR) and ST-segment of electrocardiogram(ECG) were monitored throughout the experiment. Changes of myocardial morphology were observed after hematoxylin-eosin(HE) staining. The activity of plasma lactate dehydrogenase(LDH) was tested by Microplate Reader. Myocardial infarct size was measured by TTC staining. Results: Total IPC-MVs and different phenotypes, including platelet-derived MVs(PMVs), endothelial cell-derived MVs(EMVs), leucocyte-derived MVs(LMVs) and erythrocyte-derived MVs(RMVs) were all isolated which were identified membrane vesicles(<1 μm) with corresponding antibody positive. The numbers of PMVs, EMVs and RMVs were significantly increased in circulation of IPC treated rats(P<0.05, respectively). In addition, at the end of 120-min reperfusion in I/R injured rats, IPC-MVs markedly increased HR(P<0.01), decreased ST-segment and LDH activity(P<0.05, P<0.01). The damage of myocardium was obviously alleviated and myocardial infarct size was significantly lowered after IPC-MVs treatment(P<0.01). Conclusion: The method of flow cytometry was successfully established to detect the phenotypes and concentration alteration of IPC-MVs, including PMVs, EMVs, LMVs and RMVs. Furthermore, circulating IPC-MVs protected myocardium against I/R injury in rats.

Changes of cTnI in myocardial ischemic and reperfusion injury during correction of cardiac defects in children

Objective The purpose of this study is to investgate changes of cTnI in myocardial ischemic and reperfusion injury during correction of cardiac defects in children. Methods From June, 1999 to May,2000,45 children (30 male, 15 female) undergoing correction of cardiac defects were divided into three groups randomly: group Ⅰ no myocardial ischemia,group Ⅱ myocardial ischemia less than 60 minutes, group Ⅲmyocardial ischemia 】 60 minutes. There were no significant differences in the three groups in age, sex ratio, C/T ratio, or left ventricular function. Blood samples for analysis were collected before skin incision and at time intervals up to 6 days postoperatively. Analysis of creatine kinase MB.LDH and cardiac-specific troponin I was used for the detection of myocardial damage. Meantime, the ECG was checked for myocardial infarction. After the reperfusion, myocardial tissue was obtained from the free wall of right ventricle myocardial structure studies. Results The level of cTnI was increased

The role of glycogen synthase kinase 3 beta in brain injury induced by myocardial ischemia/reperfusion injury in a rat model of diabetes mellitus

Myocardial ischemia/reperfusion injury can lead to severe brain injury.Glycogen synthase kinase 3 beta is known to be involved in myocardial ischemia/reperfusion injury and diabetes mellitus.However,the precise role of glycogen synthase kinase 3 beta in myocardial ischemia/reperfusion injury-induced brain injury is unclear.In this study,we observed the effects of glycogen synthase kinase 3 beta on brain injury induced by myocardial ischemia/reperfusion injury in diabetic rats.Rat models of diabetes mellitus were generated via intraperitoneal injection of streptozotocin.Models of myocardial ischemia/reperfusion injury were generated by occluding the anterior descending branch of the left coronary artery.Post-conditioning comprised three cycles of ischemia/reperfusion.Immunohistochemical staining and western blot assays demonstrated that after 48 hours of reperfusion,the structure of the brain was seriously damaged in the experimental rats compared with normal controls.Expression of Bax,interleukin-6,interleukin-8,terminal deoxynucleotidyl transferase d UTP nick end labeling,and cleaved caspase-3 in the brain was significantly increased,while expression of Bcl-2,interleukin-10,and phospho-glycogen synthase kinase 3 beta was decreased.Diabetes mellitus can aggravate inflammatory reactions and apoptosis.Ischemic post-conditioning with glycogen synthase kinase 3 beta inhibitor lithium chloride can effectively reverse these changes.Our results showed that myocardial ischemic post-conditioning attenuated myocardial ischemia/reperfusion injury-induced brain injury by activating glycogen synthase kinase 3 beta.According to these results,glycogen synthase kinase 3 beta appears to be an important factor in brain injury induced by myocardial ischemia/reperfusion injury.

N-乙酰半胱氨酸联合缺血后处理减轻糖尿病小鼠心肌缺血再灌注后肺损伤的作用研究

目的研究N-乙酰半胱氨酸(NAC)联合缺血后处理(IPostC)对糖尿病小鼠心肌缺血再灌注后肺损伤的作用。方法选择15周龄雄性db/db糖尿病小鼠30只,分为假手术组(D-SO组,n=10)、心肌缺血/再灌注组(D-I/R组,n=10)和NAC联合缺血后处理组(D-NAC+IPostC组,n=10)。D-SO组小鼠开胸后不做任何处理;D-I/R组小鼠干预为冠状动脉左前降支结扎60 min,后复灌15 min。D-NAC+IPostC组在结扎冠状动脉左前降支前30 min腹腔注射NAC150 mg/kg,缺血后处理的干预方式为小鼠缺血60 min后即刻进行3个周期再灌注/缺血,然后再灌注15 min。于再灌注结束后颈动脉取血,检测血清C反应蛋白(CRP)、肿瘤坏死因子-α(TNF-α)、单核细胞趋化蛋白-1(MCP-1)水平,处死小鼠,取肺组织,检测湿干重(W/D)比值,光镜下观察肺组织病理形态学变化,计算肺损伤评分,测定肺组织氧化应激相关标志物谷胱甘肽(GSH)、超氧化物歧化酶(SOD)及丙二醛(MDA)水平,采用Western Blot法检测肺组织缺氧诱导因子1α(HIF-1α)和血管内皮生长因子(VEGF)的表达水平。结果与D-SO组比较,D-I/R组小鼠光镜下病理学损伤严重(P<0.05),肺W/D比值增加(P<0.05),血清TNF-α、CRP水平降低(P<0.05),MCP-1水平升高(P<0.05),肺组织MDA含量增加(P<0.05),SOD及GSH活性降低(P<0.05),肺组织HIF-1α及VEGF表达上调(P<0.05)。与D-I/R组比较,D-NAC+IPostC组肺组织镜下病理学损伤明显减轻(P<0.05),肺W/D比值降低(P<0.05),血清TNF-α、MCP-1水平降低(P<0.05),CRP水平升高(P<0.05),肺组织氧化应激因子MDA含量降低(P<0.05),抗氧化应激因子SOD及GSH活性升高(P<0.05),肺组织HIF-1α、血管内皮生长因子(VEGF)水平表达增高(P<0.05)。结论NAC联合IPostC可减轻糖尿病心肌缺血再灌注小鼠肺损伤,其机制可能与HIF-1α/VEGF信号通路相关。

双下肢缺血后处理保护再灌注心肌时效性及对线粒体通路调控的研究

目的:观察双下肢缺血后处理(即远隔器官缺血后处理,remote ischemic postconditioning,RIpostC)保护缺血再灌注小鼠心肌的时效性及对心肌线粒体依赖性凋亡和坏死通路的调控。方法:成年雄性C57BL/6J野生型小鼠被随机分为假手术(sham)组、心肌缺血再灌注(myocardial ischemia/reperfusion,MI/R)组、缺血后处理组、RIpostC组及RIpostC延迟1、5、10、15、30和60 min组。阻断左冠脉45 min,再灌注24 h,建立MI/R模型;气囊袖带阻断双下肢血流5 min,再灌注5 min,实施RIpostC。再灌注24 h后,Evans blue和TTC染色观察心肌梗死面积与血清心肌钙蛋白I变化。TUNEL和高迁移率族盒蛋白1(high mobility group box protein 1,HMGB1)染色观察心肌凋亡和坏死;线粒体水肿实验观察心肌线粒体膜电位变化;Western blot观察心肌细胞凋亡和线粒体膜通透性转换孔(mitochondrial permeability transition pore,mPTP)相关蛋白表达。结果:与MI/R组比较,RIpostC及RIpostC延迟1、5、10和15 min组心肌梗死面积明显减少,RIpostC延迟30和60 min组则无明显改变。缺血后处理与RIpostC对缺血再灌注心肌有类似保护效应。RIpostC减少缺血再灌注心肌细胞凋亡和坏死发生。RIpostC降低缺血再灌注心肌亲环蛋白D(cyclophilin D,CypD)、Bax和Bak蛋白表达水平。结论:心肌再灌注后15 min内实施RIpostC能够减少心肌梗死面积,其保护作用与缺血后处理类似;RIpostC通过调控线粒体依赖性凋亡和坏死通路减轻MI/R损伤。

2012—2022年针灸治疗心肌缺血再灌注损伤的动物实验分析

目的系统分析2012—2022年针灸治疗心肌缺血再灌注损伤(myocardial ischemia reperfusion injury,MIRI)的动物实验研究情况,为今后的实验研究提供参考。方法查阅2012年1月1日—2022年6月1日中国知网、维普、万方、CBM、PubMed和Web of Science数据库发表的文献,对纳入文献的实验动物、造模方法、干预方案、对照组措施和结局指标等信息进行总结分析。结果共纳入164篇文献,文献研究所用实验动物有大鼠、小鼠和兔子;干预措施涉及电针(n=149)、艾灸(n=16)等,电针治疗中有81篇针刺单穴内关,31篇针刺内关相关配穴,频率以2/100 Hz、2 Hz为多,刺激强度主要为1 mA,治疗时间以20 min为多;结局指标涉及形态学、功能学及分子生物学。结论目前的研究肯定了针灸治疗MIRI的效果,在今后的研究中建议多关注实验动物选择、穴位配伍、针灸干预方案、干预手段联合作用效果的比较,注重对作用机制和临床应用的探索,最终指导临床提高临床疗效。

中医药调控间充质干细胞治疗心肌缺血再灌注损伤的研究进展

各类心血管疾病心肌缺血后再次恢复血流信号导致心肌组织的二次损伤,称为心肌缺血再灌注损伤(myocardial ischemia-reperfusion injury,MIRI)。间充质干细胞(mesenchymal stem cells,MSCs)是一类具有较强的增殖、免疫、分化及改善心肌功能等能力的干细胞。目前已有研究揭示MSCs对于抑制心肌炎症反应、防治心肌细胞凋亡及促进心肌血管再生等过程具有十分重要的作用。因此,促进MSCs的增殖,诱导其分化成心肌细胞,可在一定程度上减轻MIRI。而大量研究表明中医药对于MSCs具有诱导性,并有增强其功能的作用。结合三者之间的关系,可得出中医药具有调控MSCs治疗MIRI作用。文章通过对中药单体及复方调控MSCs治疗MIRI相关文献进行查阅,主要梳理了MSCs对MIRI的影响,对中医药调控MSCs治疗MIRI的实验成果及机制的相关研究进行综述,以助寻求新的MIRI临床治疗策略和可靠的依据。

匝迪-5味丸改善心肌缺血再灌注损伤的作用机制预测及验证

目的探讨匝迪-5味丸改善心肌缺血再灌注损伤(MIRI)的作用机制。方法通过网络药理学方法筛选匝迪-5味丸改善MIRI的潜在作用靶点和通路。将72只大鼠随机分为模型组、假手术组、丹参组[复方丹参滴丸80 mg/(kg·d)]和匝迪-5味丸高、中、低剂量组[1.6、0.8、0.4 g/(kg·d)],每组12只。各组大鼠灌胃相应药物,每天1次,连续14 d。末次给药后,结扎大鼠左冠状动脉前降支建立MIRI模型,假手术组大鼠只穿线不结扎。检测建模后各组大鼠血清中肌酸激酶(CK)、乳酸脱氢酶(LDH)、天冬氨酸转氨酶(AST)、心肌肌钙蛋白T(CTn-T)的含量,心肌细胞凋亡率,心肌组织中磷脂酰肌醇3-激酶(PI3K)、蛋白激酶B(Akt)、B淋巴细胞瘤2(Bcl-2)及Bcl-2相关X蛋白(Bax)、胱天蛋白酶3(caspase-3)蛋白表达水平;观察心肌组织形态变化。结果共获得匝迪-5味丸的活性成分177个,作用靶点220个,参与改善心肌缺血相关的靶点51个,其中核心靶点为AKT1,涉及PI3K-Akt、内质网、缺氧诱导因子-1等多个通路。与模型组比较,丹参组和匝迪-5味丸高剂量组大鼠血清中CK、LDH、AST、CTn-T含量和心肌细胞凋亡率,以及心肌组织中caspase-3、Bax蛋白表达水平均显著降低(P<0.05或P<0.01),心肌组织中PI3K、Akt、Bcl-2蛋白表达水平均显著升高(P<0.05或P<0.01),心肌组织病理形态改变均明显改善;匝迪-5味丸低、中剂量组大鼠上述指标亦有不同程度改善。结论匝迪-5味丸可能通过激活PI3K-Akt信号通路抑制细胞凋亡,从而发挥改善MIRI的作用。

缺血后适应对急性ST段抬高型心肌梗死患者PCI介入术后缺血-再灌注损伤的预后影响

目的:观察缺血后适应(IPoC)对急性ST段抬高型心肌梗死(STEMI)患者经皮冠状动脉介入术(PCI)后缺血-再灌注损伤(IRI)预后影响。方法:将90例STMEI患者按照不同治疗方式分为对照组(常规方法行PCI)和观察组(再灌注开始1 min内行IPoC),每组各45例。比较两组患者ST段回落情况,心肌再灌注评价,心肌坏死标志物,心功能指标,外周血氨基末端B型钠尿肽原(NT-proBNP)、超敏C反应蛋白(hs-CRP)、内皮素1(ET-1)和主要心脏不良事件。结果:观察组患者术后6 h完全回落高于术后2 h(P<0.05);术后心肌再灌注评价指标CTFC和WMSI,心肌坏死标志物c-TnI、CK和CK-MB,外周血NT-proBNP、hs-CRP和ET-1水平均低于对照组(P<0.05);主要心脏不良事件发生率低于对照组(P<0.05)。结论:IPoC能有效改善STMEI患者PCI介入后IRI,能降低心肌酶和NT-proBNP、hs-CRP和ET-1水平,改善预后,值得临床应用推广。

心肌缺血再灌注损伤大鼠HMGB1表达水平的Meta分析

目的对心肌缺血再灌注损伤(MIRI)大鼠高迁移率族蛋白B1(HMGB1)表达水平进行Meta分析。方法在PubMed、Embase及中国国家知识基础设施(CNKI)数据库检索相关文章,最终共纳入16篇文献,从这些文章中提取假手术组、模型组、预处理组的样本量、均数和标准差,采用SYRCLE动物实验风险评估工具进行方法学质量评价,应用Stata12.0软件进行Meta分析。结果MIRI大鼠模型组HMGB1表达水平显著高于假手术组(SMD=8.66,95%CI:6.49~10.82,P<0.001),MIRI大鼠预处理组HMGB1表达水平明显低于模型组(SMD=-3.33,95%CI:-4.22~-2.44,P<0.001)。亚组分析表明,不同预处理方式可能导致异质性存在。敏感性分析显示Meta分析结果可信度较高,而漏斗图显示存在发表偏倚。结论MIRI大鼠HMGB1表达水平升高,通过治疗可降低MIRI大鼠HMGB1表达水平。

热休克预处理对大鼠在体MIRI的保护效应

目的探讨热休克预处理对大鼠在体MIRI的保护效应。方法健康成年雄性Wist-ar大鼠30只,随机分三组:SO组、MIRI组、HS组。左冠状动脉结扎法建立MIRI模型。各组经预处理后,动态监测LVSP、±dp/dtmax、LVEDP等血流动力学指标,检测血浆CK-MB、SOD、MDA等生化指标。术毕光镜下观察心肌组织病理变化。结果与MIRI组比较,HS组复灌末LVEDP水平明显降低(P<0.05)、LVSP、±dp/dtmax水平升高(P<0.05)、血浆CK-MB漏出量明显减少(P<0.05)、血浆MDA水平降低(P<0.05)、SOD活性升高(P<0.05)。光镜下,HS组心肌纤维排列较整齐,未见细胞间连接点断裂,闰盘少见。结论热休克预处理对大鼠在体MIRI具有保护作用,其保护机制可能与抗自由基损伤有关。

参附注射液灌胃对MIRI模型大鼠Ca^(2+)、KATP通道的影响

目的探讨参附注射液(SFI)灌胃对心肌缺血再灌注损伤(MIRI)模型大鼠Ca^(2+)、KATP通道的影响。方法选取健康SD大鼠21只,随机分为三组,建立MIRI模型,观察组SFI灌胃给药,对照组SFI+格列本脲灌胃给药,缺血再灌注组于缺血前15 min静脉输注生理盐水。观察三组超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)、肿瘤坏死因子-α(TNF-α)、血清白细胞介素-6(IL-6)、心肌肌钙蛋白I(cTnI)、肌酸激酶(CK)水平。结果观察组及对照组的SOD水平显著高于缺血再灌注组,MDA、GSH-Px、TNF-α、IL-6、cTnI、CK水平显著低于缺血再灌注组(P<0.05)。结论 SFI可提高MIRI模型大鼠机体清除氧自由基能力,降低细胞损伤,减少Ca^(2+)内流,提高ATP水平,抑制炎症因子,对心肌灌注再损伤具有保护作用,而ATP水平提高后KATP通道则未开放。

基于CiteSpace的中医药防治心肌缺血再灌注损伤知识图谱分析

目的探讨国内外中医药防治心肌缺血再灌注损伤(Myocardial ischemia reperfusion injury,MIRI)的发展前沿及研究热点,为进一步相关研究提供参考。方法检索CNKI和WOS建库至2023年10月31日期间中医药防治MIRI的文献,用CiteSpace 6.2.R4进行作者合作网络图谱、机构合作网络图谱、关键词聚类图谱、关键词突现图谱展示并进行分析。结果共纳入2865篇中文文献,160篇英文文献,国内外主要受关注的研究作者分别是李冀和Jin Chen、主要研究机构分别是黑龙江中医药大学和Chinese Academy of Medical Sciences-Peking Union Medical College,关键词共现及突现分析表明国内外MIRI中医药干预措施包括中药、中药复方、中药单体、电针,研究热点为铁死亡、细胞焦亡和内质网应激。结论在中医药防治MIRI研究中,应加强国内研究团队之间的合作,促进国内研究机构的联系,结合研究热点,全面发展该领域。

lncRNA MALAT1/HMGB1在缺血后处理减轻缺血再灌注损伤中的作用

目的探讨长链非编码RNA(long non-coding RNA,lncRNA)肺腺癌转录子1(MALAT1)以及下游调控蛋白高迁移率族蛋白B1(High-mobility group protein box-1,HMGB1)在缺血后处理降低大鼠心肌缺血-再灌注损伤(ischemia/reperfusion injury,IRI)中的作用。方法将24只大鼠饲养7天后,随机分成3组:假手术(Sham)组、缺血再灌注(ischemia/reperfusion,IR)组、缺血后处理(ischemic post-conditioning,IPO)组。模型构建完毕24 h进行检测大鼠血清中心肌肌钙蛋白I(cTnI)和白介素6(IL-6)表达水平,取材检测大鼠心肌梗死面积,检测大鼠心肌组织中MALAT1转录表达水平的差异,HMGB1、Toll样受体4(Toll-like receptor4,TLR4)蛋白含量差异。结果与Sham组比较,IR、IPO组血清中cTnI、IL-6水平明显升高,心肌梗死面积明显增加,心肌组织中MALAT1表达水平显著上调,HMGB1、TLR4水平明显升高(P<0.05)。与IR组比较,IPO组cTnI浓度显著降低,心肌梗死面积显著减小,心肌组织中lncRNA-MALAT1相对表达量降低,HMGB1、TLR4蛋白含量降低(P<0.05)。结论及时的缺血后处理可有效减缓大鼠心肌缺血-再灌注的损伤程度,其相关机制可能与抑制MALAT1调节控制HMGB1、TLR4表达水平之间有一定的关联。

加味瓜蒌薤白汤对大鼠心肌缺血再灌注损伤的保护作用

目的:观察加味瓜蒌薤白汤对心肌缺血再灌注损伤(myocardial ischemia reperfusion injury,MIRI)大鼠心功能指标和心肌组织病理形态的影响。方法:将64只Wistar大鼠随机分为对照组11只、模型组11只、加味瓜蒌薤白汤低剂量组(1.134 g·kg^(-1))11只、中剂量组(2.268 g·kg^(-1))11只、高剂量组(4.536 g·kg^(-1))10只及复方丹参滴丸组(86 mg·kg^(-1))10只。除对照组外,其余大鼠采用结扎冠状动脉的方式建立MIRI模型。造模成功后,各药物组以相应药物灌胃,对照组和模型组给予生理盐水灌胃,每日1次,共7 d。采用ELISA法检测大鼠血清肌钙蛋白T(cardiac troponin T,CTNT)、内皮素-1(endothelin-1,ET-1)、血栓素B2(thromboxane B2,TXB2)含量;采用超声心动图检测大鼠左室舒张末期内径(left ventricular internal dimension diameter,LVIDd)、左室射血分数(left ventricular ejection fraction,LVEF)、左室收缩末期内径(left ventricular internal systolic diameter,LVIDs)、心输出量(cardiac output,CO)、左室舒张末期容积(left ventricular internal diastolic volume,LVEDV)、每搏输出量(stroke volume,SV)、左室收缩末期容积(left ventricular internal systolic volume,LVESV);采用HE染色观察大鼠心肌组织病理形态。结果:与对照组比较,模型组大鼠血清CTNT、ET-1和TXB2含量升高(P<0.05);与模型组比较,加味瓜蒌薤白汤中剂量组和复方丹参滴丸组大鼠血清CTNT、ET-1和TXB2含量降低(P<0.05)。与对照组比较,模型组大鼠LVIDd、LVEDV增加(P<0.01),且LVIDs、LVESV、SV、CO、LVEF减少(P<0.05);与模型组比较,加味瓜蒌薤白汤中剂量组和复方丹参滴丸组大鼠LVIDd、LVEDV减少(P<0.05),且LVIDs、LVESV、SV、CO、LVEF增加(P<0.05)。HE染色结果显示,对照组大鼠心肌细胞排列整齐,无炎症细胞浸润;模型组大鼠大量心肌纤维呈不规则排列,心肌间质水肿和坏死;加味瓜蒌薤白汤高剂量组大鼠心肌细胞轻度肿胀,肌原纤维排列较规则;复方丹参滴丸组大鼠心包膜下心肌细胞坏死,中性粒细胞浸润,间质充血水肿。结论:加味瓜蒌薤白汤对大鼠MIRI具有显著的保护作用。

羟考酮在心肌缺血再灌注损伤中的作用

缺血性心脏病是全球最重要的死亡原因之一,而心肌缺血再灌注损伤(MIRI)是缺血性心脏病常见的并发症。目前,临床上尚无针对MIRI的有效防治方法。在过去几十年里,羟考酮不仅作为镇痛药得到广泛应用,并且由很多研究发现其对于保护心肌组织的MIRI有一定作用。该综述主要围绕羟考酮能够通过抑制氧化应激,抑制炎性因子表达,保护心肌内皮细胞完整性等对MIRI起到治疗与预防作用。旨在回顾已发表的关于羟考酮在MIRI中的相关作用机制,并为该领域的进一步研究提供参考。

利用正交试验筛选阿魏酸等四种药物干预在体大鼠MIRI凋亡最佳组合

目的利用正交实验方法探究阿魏酸、芍药苷、甘草酸及肉桂酸四种药物组合预处理对大鼠在体心肌缺血再灌注损伤(MIRI)的心肌细胞凋亡的干预作用,并寻找最佳药物组合。方法本实验采用了结扎SD大鼠心脏冠状动脉前降支(LA)的方法建立在体大鼠心肌缺血再灌注损伤模型;采用L16(44)正交实验设计和0.5%Evan's蓝灌注心肌及1%TTC磷酸缓冲液孵育心肌观察心肌坏死;利用TUNEL法检测心肌细胞凋亡。结果比较各因素的极差发现阿魏酸、甘草酸、芍药苷、肉桂酸对大鼠MIRI模型心肌梗死面积影响的顺序是:芍药苷>甘草酸>阿魏酸>肉桂酸;阿魏酸、甘草酸、芍药苷、肉桂酸对大鼠MIRI模型的心肌细胞凋亡指数影响的顺序是:芍药苷>甘草酸>肉桂酸>阿魏酸;阿魏酸、甘草酸、芍药苷、肉桂酸四药混合干预大鼠MIRI心肌细胞凋亡指数最佳选择方案是:芍药苷(高剂量,100 mg/kg)、甘草酸(高剂量,100 mg/kg)、阿魏酸(中剂量,300 mg/kg)、肉桂酸(中剂量,200 mg/kg)。结论芍药苷(高剂量,100 mg/kg)、甘草酸(高剂量,100 mg/kg)、阿魏酸(中剂量,300 mg/kg)、肉桂酸(中剂量,200 mg/kg)组合是降低心肌细胞凋亡、减少心肌梗死面积的最佳组合。

Role of Beclin 1-dependent Autophagy in Cardioprotection of Ischemic Preconditioning

Emerging evidence indicates that ischemic preconditioning （IPC） induces autophagy which attenuates myocardial ischemia/reperfusion （I/R） injury. However, the precise mechanisms remain com- plex and unclear. The present study was to investigate which autophagy pathway was involved in the cardioprotection induced by IPC, so that we can acquire an attractive treatment way for iscbemic heart disease. Adult male Sprague-Dawley （SD） rats were randomly divided into sham group, I/R group and IPC group. IPC was induced with three cycles of 5 min regional ischemia alternating with 5 m^n reper- fusion in a heart I/R model. Samples were taken from the center of the infracted heart and examined by using the electron microscopy, the terminal deoxynucleotidyl transferase-mediated nick end-labeling （TUNEL） method, Western blotting and co-immunoprecipitation （Co-IP）. A large number of autophagic vacuoles were observed in the cardiomyocytes oflPC group as compared with I/R group. LC3-II forma- tion, an autophagy marker, was up-regulated in IPC group as compared with FR group （P〈0.05）. Moreover, the interaction between Beclin 1 and Bcl-2 was significantly increased in IPC group as com- pared with I/R group （P〈0.01）. It was also found that IPC decreased I/R-induced apoptosis （P〈0.01）. These results suggest that IPC inhibits Beclin 1-dependent excessive autophagy in reperfusion phase and cooperates with anti-apoptosis pathway to diminish the cell death induced by the myocardial I/R injury.

姜黄素通过调节HMGB1/NF-κB通路对大鼠心肌缺血再灌注损伤的保护作用研究

目的:探讨姜黄素对大鼠心肌缺血再灌注损伤(MI/RI)的保护作用及可能机制。方法:100只健康8周龄Sprague-Dawley大鼠采用随机数字表法分为假手术组、模型组、地尔硫䓬组、姜黄素组,每组25只。H9c2细胞分为对照组、缺氧/复氧组、姜黄素组。采用冠状动脉结扎法构建大鼠MI/RI模型,H9c2心肌细胞缺氧/复氧体外模拟MI/RI。采用BL-420S生物功能实验系统采集心电图(ECG)测量值;四唑盐(MTT)法测定H9c2细胞活性;酶联免疫吸附测定法(ELISA)测定血清和细胞上清液中的炎性细胞因子水平;苏木精-伊红(HE)染色及2,3,5-三苯基氯化四唑(TTC)观察损伤的心肌组织情况。蛋白质免疫印迹法(Western Blot)检测高迁移率族蛋白B1(HMGB1)/核转录因子-κB(NF-κB)通路相关蛋白水平。结果:TTC染色结果显示,姜黄素组心肌灰色改变较模型组少,地尔硫䓬组与姜黄素组心肌组织病理学无明显差异;苏木精-伊红(HE)染色结果显示,姜黄素组心肌组织纤维排列尚规则,无明显出血、水肿等改变,炎性细胞数量较少,地尔硫䓬组与姜黄素组心肌组织病理学则无明显差异。与假手术组比较,模型组ST段明显抬高(P<0.05);与模型组比较,姜黄素组ST段明显降低(P<0.05)。地尔硫䓬组与姜黄素组ST段比较,差异无统计学意义(P>0.05)。与对照组比较,缺氧/复氧组、姜黄素组H9c2细胞活力降低(P<0.05);与缺氧/复氧组比较,姜黄素组H9c2细胞活力明显升高(P<0.05)。与假手术组比较,模型组、地尔硫䓬组、姜黄素组大鼠血清白细胞介素(IL-)6、IL-1β、肿瘤坏死因子-α(TNF-α)、肌酸激酶(CK)、乳酸脱氢酶(LDH)水平,HMGB1、p-IκBα、p-NF-κB p65蛋白水平明显升高(P<0.05);与模型组比较,地尔硫䓬组、姜黄素组大鼠血清IL-6、IL-1β、TNF-α、CK、LDH水平,HMGB1、p-IκBα、p-NF-κB p65蛋白水平明显降低(P<0.05)。与对照组比较,缺氧/复氧组、姜黄素组H9c2细胞上清液中IL-6、IL-1β、TNF-α、CK、LDH水平,HMGB1、p-IκBα、p-NF-κB p65蛋白表达水平明显升高(P<0.05);与缺氧/复氧组比较,姜黄素组H9c2细胞上清液中IL-6、IL-1β、TNF-α、CK、LDH水平,HMGB1、p-IκBα、p-NF-κB p65蛋白表达水平明显降低(P<0.05)。结论:姜黄素对大鼠心肌MI/RI损伤有保护作用,其机制可能与其参与HMGB1/NF-κB通路的调控有关。