黄芪甲甙对小鼠柯萨奇B3病毒性心肌炎的抗氧化作用

目的观察黄芪甲甙对小鼠柯萨奇B3病毒性心肌炎的抗氧化作用。方法Balb/c小鼠50只随机分5组(每组10只),空白对照组腹腔无菌注射不含病毒的Eagle’s培养基0.1 mL,在腹腔注射病毒培养基30 min后,以生理盐水0.1 mL灌胃,共7d;病毒性心肌炎对照组小鼠每只腹腔注射0.1 mL内含1×102TCID50柯萨奇B3病毒的Eagle’s培养基,在腹腔注射含病毒的Eagle’s培养基30 min后,以生理盐水0.1 mL灌胃,共7 d;黄芪甲甙低、中、高剂量干预组在腹腔注射病毒30 min后,用黄芪甲甙剂量分别为0.07、0.2、0.6 g/(kg.d)0.1 mL灌胃,共7 d。观察小鼠生存数;心肌病变积分;心肌谷胱甘肽过氧化物酶、过氧化氢酶、超氧化物歧化酶活力及逆转录聚合酶链反应检测铜锌超氧化物歧化酶-mRNA水平表达。结果(1)与空白对照组比较,病毒性心肌炎对照组小鼠的生存数明显下降,心肌病变积分明显升高(3.23±0.83,P<0.01);与病毒性心肌炎对照组比较,黄芪甲甙高剂量干预组可明显提高小鼠的生存数(P<0.01),心肌病变积分明显下降(1.86±0.59比3.23±0.83,P<0.01);(2)与病毒性心肌炎对照组比较,黄芪甲甙高剂量干预组心肌组织谷胱甘肽过氧化物酶、过氧化氢酶、超氧化物歧化酶活力呈增高趋势,心肌组织谷胱甘肽过氧化物酶(39.73±8.02比9.99±2.71,P<0.05)、过氧化氢酶(6.35±2.33比1.36±0.87,P<0.05)、超氧化物歧化酶(65.71±4.93比40.15±6.03,P<0.01)活力明显增强,铜—锌超氧化物歧化酶-mRNA水平表达明显增高(0.43±0.11比0.32±0.01,P<0.01)。但黄芪甲甙低、中剂量干预组,虽然也在一定程度使心肌组织谷胱甘肽过氧化物酶、过氧化氢酶、超氧化物歧化酶活力及逆转录聚合酶链反应检测铜—锌超氧化物歧化酶-mRNA表达水平增加,有一定的量效关系,但与病毒性心肌炎对照组比较无统计学意义(P>0.05)。结论黄芪甲甙通过增加心肌抗氧化酶活力,对小鼠柯萨奇B3病毒性心肌炎具有明显的保护作用。     

Vγ1+γδT,early cardiac infiltrated innate population dominantly producing IL-4, protect mice against CVB3 myocarditis by modulating IFNγ+ T response

Viral myocarditis (VMC) is an inflammation of the myocardium closely associated with Coxsackievirus B3 (CVB3) infection. Vγ1⁺γδT cells, one of early cardiac infiltrated innate population, were reported to protect CVB3 myocarditis while the precise mechanism not fully addressed. To explore cytokine profiles and kinetics of Vγ1⁺γδT and mechanism of protection against VMC, flow cytometry was conducted on cardiac Vγ1 cells in C57BL/6 mice following CVB3 infection. The level of cardiac inflammation, transthoracic echocardiography and viral replication were evaluated after monoclonal antibody depletion of Vγ1γδT. We found that Vγ1⁺γδT cells infiltration peaked in the heart at day3 post CVB3 infection and constituted a minor source of IFN-γ but major producers for early IL-4. Vγ1γδT cells were activated earlier holding a higher IL-4-producing efficiency than CD4⁺Th cells in the heart. Depletion of Vγ1⁺γδT resulted in a significantly exacerbated cardiac infiltration, increased T, macrophage and neutrophil population in heart homogenates and worse cardiomyopathy; which was accompanied by a significant expansion of peripheral IFNγ⁺CD4+ and CD8 + T cells. Neutralization of IL-4 in mice resulted in an exacerbated acute myocarditis confirming the IL-4-mediated protective mechanism of Vγ1. Our findings identify a unique property of Vγ1⁺γδT cells as one dominant early producers of IL-4 upon CVB3 acute infection which is a key mediator to protect mice against acute myocarditis by modulating IFNγ-secreting T response.     

Internalization and trafficking mechanisms of coxsackievirus B3 in HeLa cells

Coxsackievirus B3 (CVB3) is nonenveloped and has a single-stranded positive-sense RNA genome. CVB3 induces myocarditis and ultimately dilated cardiomyopathy. Although there are mounting evidences of an interaction between CVB3 particles and the cellular receptors, coxsackievirus and adenovirus receptor (CAR) and decay-accelerating factor (DAF), very little is known about the mechanisms of internalization and trafficking. In the present study, we used the CVB3 H3 strain, which is CAR-dependent but DAF-independent Woodruff variant and found that during entry, CVB3 particles were colocalized in clathrin, after interacting primarily with CAR, which was not recycled to the plasma membrane. We also found that CVB3 internalization was dependent on the function of dynamin, a large GTPase that has an essential role in endocytosis. Heat-shock cognate protein, Hsc70, which acts as a chaperone in the release of coat proteins from clathrin-coated vesicles (CCV), played a role in CVB3 trafficking processes. Moreover, endosomal acidification was crucial for CVB3 endocytosis. Finally, CVB3 was colocalized in early endosome autoantigen 1 (EEA1) molecules, which are involved in endosome-endosome tethering and fusion. In conclusion, these data together indicate that CVB3 uses clathrin-mediated endocytosis and is transcytosed to early endosomes.     

Gene therapy with CCL2 (MCP-1) mutant protects CVB3-induced myocarditis by compromising Th1 polarization

Viral myocarditis, which is most prevalently caused by Coxsackievirus B3 (CVB3) infection, affects about 5-20% of the world population and lacks efficient treatments. We previously reported that monocyte chemotactic protein-1 (MCP-1, CCL2) was significantly induced during CVB3 infection and greatly contributed to the myocardic inflammation and injury. Herein a CCL2 mutant with removed chemotactic activity was administrated and its therapeutic effect on CVB3-induced myocarditis was explored. A dominant negative CCL2 mutant, lacking the N-terminal amino acids 2-8 (CCL2^Δ2-8), was genetically constructed and intramuscularly injected into BALB/c mice after CVB3 infection, severity of myocarditis was evaluated by weight loss, survival rate, serological indices and pathological observation. Systemic and local Th1/Th2 cytokine profiles were also assessed. Mice receiving pCCL2^Δ2-8 exhibited a profound attenuation of myocarditis compared to pcDNA3.1 or non-treated mice, as evidenced by invariant body weight, decreased serum CK-MB level, reduced myocardial inflammatory infiltration and increased survival. This effect was not attributable to the efficient viral clearance, but associated with weakened Th1 immune responses, as evidenced by significantly reduced CD4⁺IFN-γ⁺ T cell frequency and Th1 cytokine level systemically and locally. Strategy of blocking in vivo CCL2 activity could effectively alleviate the severity of CVB3-induced myocarditis and may present an alternative therapeutic approach against viral myocarditis.     

C家族趋化因子XCL 1增强CVB3基因疫苗的抗病毒免疫应答及保护作用

为提高以往构建的基因疫苗pcDNA3.1-VP1的抗B3型柯萨奇病毒(CVB3)感染的免疫效果,以编码C家族趋化因子XCL1的质粒pcDNA3.1-XCL1共注射,观察诱导的CVB3特异性免疫应答及CVB3病毒性心肌炎预防效果。将两种质粒各50μg混合后分别于0、2、4、6周肌注免疫小鼠4次,末次免疫后4周分别以5×LD50剂量CVB3攻击小鼠观察保护率,或以3×LD50剂量CVB3感染小鼠观察病毒性心肌炎的诱生。结果显示,与单纯pcDNA3.1-VP1质粒相比,XCL1质粒共注射可增强血清CVB3特异性IgG以及特异性CTL应答。5×LD50病毒攻击后,共注射组体重降低7.28%,而pcDNA3.1-VP1组体重降低10.97%;共注射组28 d保护率达40%,高于pcDNA3.1-VP1组的30%。3×LD50病毒感染后心肌组织病理显示,共注射组心外膜下仅有轻微炎症,心肌内未见炎症细胞浸润,而pcDNA3.1-VP1组除心外膜下有较多淋巴细胞聚集外,心肌内有少量炎症浸润和坏死灶。提示XCL1质粒共注射可增强CVB3特异性体液和细胞免疫应答及抗病毒保护,可有效预防病毒性心肌炎的发生。     

感染柯萨奇病毒B3诱导人心肌纤维细胞因子的产生

目的：CVB3感染可导致严重的心脏病，其机制尚不清楚，细胞因子可能有重要作用，但确切来源细胞尚不清楚，心肌纤维细胞是主要间质分子，感染CVB3后检测其细胞因子的产生。方法：采用ELISA方法检测了感染CVB3心肌纤维细胞培养上清液IL－6、IL－8、IL－1α、IL－1β和TNF－α的产生，结果：发现感染CVB3 24小时后IL－6和IL－8即明显升高（P＜0．01），96小时后IL－1α有所升高（P＜0．05），IL－1β和TNF－α无明显变化，结论：IL－6、IL－8、IL－1α在CVB3心肌炎中可能有一定作用。     

茱萸颗粒体外抗CVB3病毒的实验研究

茱萸颗粒是我院心内科李七一教授经临床多年摸索,拟定治疗病毒性心肌炎的有效良方.目的:观察茱萸颗粒对CVB3病毒的作用.方法:采用体外抗CVB3病毒和大鼠心肌细胞感染CVB3实验.结果:茱萸颗粒20mg/ml对CVB3感染Vero细胞具有明显保护作用,同时可抑制CVB3毒力.茱萸颗粒0.5mg/ml至4mg/ml可减轻CVB3感染心肌细胞CPE,心肌酶谱显示:茱萸颗粒可明显降低感染CVB3心肌细胞中LDH,LDH1,AST和HBDH释放,减少心肌细胞损坏.结论:茱萸颗粒具有抗CVB3感染和保护心肌细胞的作用.     

肉桂油治疗小鼠CVB3m病毒性心肌炎的实验研究

目的:研究肉桂油(OC)对柯萨奇病毒B3m(CVB3m)诱发性小鼠病毒性心肌炎(VMC)的治疗作用.方法:0.1 mL CVB3m ip建立BALB/c小鼠VMC模型.正常对照组同法接种0.1 mL不含病毒的Eagle液,与感染病毒小鼠隔离饲养.于接种病毒72 h后给药,OC治疗组(49.1,36.7,26.5 mg/kg肉桂油,ig)、阳性药物组(50 mg/kg黄芪注射液,ip)、模型组与正常对照组(2500 mg/kg生理盐水,ig),连续给药1 wk.观察指标:累计死亡率与中位生存时间;接种病毒后10 d心肌组织光、电镜组织病理学检查;心肌匀浆MDA含量、SOD活性;血清中乳酸脱氢酶(LDH)、肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)含量;21 d心肌组织光镜病理检查.结果:OC 49.1和36.7 mg/kg治疗组可降低小鼠死亡率,延长中位生存时间,降低急性期血清中CK,CK-MB含量以及心肌中MDA含量,提高SOD活性;减轻急性期、亚急性期小鼠心肌组织的坏死与钙化,与模型组比较差异显著(P<0.05).结论:OC具有治疗柯萨奇病毒B3m诱发性小鼠VMC的作用.     

牡荆素对CVB3诱导的病毒性心肌炎大鼠心肌损伤的保护作用及机制研究

目的：探究牡荆素（Vitexin）对大鼠心肌损伤的保护作用及机制。方法：选择Balb/c新生乳鼠腹腔注射柯萨奇病毒B3（Coxsackie virus B₃，CVB3）建立大鼠病毒性心肌炎模型，分别设置正常未感染组（对照组）、感染CVB3组（模型组）、CVB3+Vitexin（10 mg·kg^-1）组[简称Vitexin（10 mg·kg^-1）组]、CVB3+Vitexin（20 mg·kg^-1）组[简称Vitexin（20 mg·kg^-1）组]和CVB3+Vitexin（50 mg·kg^-1）组[简称Vitexin（50 mg·kg^-1）组]，连续腹腔注射给药1周。HE染色观察心肌细胞损伤水平，TUNEL染色检测肿瘤细胞凋亡。免疫组织化学法和酶联免疫吸附实验（enzyme-linked immunosorbent assay，ELISA）检测心肌炎标记分子和心肌损伤标记物。利用蛋白质免疫印迹（Western Blot）技术检测肿瘤凋亡及其下游靶基因等相关分子表达。结果：与对照组比较，模型组细胞受损严重，炎症因子、心肌损伤标志物及细胞凋亡因子显著升高（P<0.05），TGF-β1及TNF-α蛋白活性显著升高（P<0.05）。相较于模型组，Vitexin处理组心肌细胞形态正常，心肌纤维排列整齐；细胞凋亡显著减少；Vitexin处理组心肌炎症因子、心肌损伤标志物及细胞凋亡因子显著低于模型组（P<0.05）。TGF-β1及TNF-α蛋白活性显著降低（P<0.05）；并且Vitexin高剂量优于低剂量组。结论：Vitexin可以减少细胞凋亡，降低炎症因子水平来保护心肌炎症细胞受到CVB3病毒诱导的损伤；Vitexin可能是通过抑制TGF-β1及TNF-α蛋白活性来发挥影响。     

生脉散提取物对实验性病毒性心肌炎的作用

目的：观察生脉散提取物(SMT)对实验性病毒性心肌炎的治疗作用。方法：BAIB／c小鼠腹腔注射CVB3后，第4天出现病毒性心肌炎体征，到第8天病变到达高峰，形成病毒性心肌炎动物模型。通过观察小鼠体重变化，血清中LDH、AST和MDA的含量，心肌组织中病毒滴度，心肌组织病理变化和超微结构变化，研究SMT对实验性病毒性心肌炎的治疗作用。结果：SMT提高心肌炎小鼠的体重增长速度；降低血清中LDH、AST及MDA的含量；改善心脏病理变化，改善心肌组织的超微结构；抑制病毒在心肌组织内的增殖。结论：SMT对病毒性心肌炎有一定的治疗作用，其作用机理与抗氧化和抑制病毒在心肌组织中复制有关。