Astragaloside IV attenuates myocardial fibrosis by inhibiting TGF-β1 signaling in coxsackievirus B3-induced cardiomyopathy

Myocardial fibrosis plays an important role in coxsackievirus B3 (CVB3) induced dilated cardiomyopathy. Excessive transforming growth factor (TGF)-β1 contributes to a pathologic excess of tissue fibrosis. We investigated the effect of astragaloside IV on myocardial fibrosis in CVB3-induced dilated cardiomyopathy. BALB/c mice were inoculated with CVB3 to induce acute viral myocarditis on day 7 (acute VMC group), monthly for 3 months to induce chronic myocarditis (chronic VMC group), and monthly for 9 months to induce dilated cardiomyopathy (DCM group). The same method was used for the DCM+Astra group as that of the DCM group, but former group was given with astragaloside IV-containing drinking water. Compared to DCM group, astragaloside IV treatment significantly increased the survival rate. Histological findings and the collagen volume fraction showed that astragaloside IV decreased fibrosis in heart tissues. Astragaloside IV decreased the level of the serum carboxy-terminal propeptide of procollagen type I (PICP) and the ratio of PICP/ N-terminal type I procollagen propeptide (PINP). Ameliorated myocardial fibrosis was consistent with the downregulated expression of TGF-β1 and its downstream pSmad2/3 and Smad4 in the myocardium of the DCM+Astra group compared to the DCM group. The level of type I collagen was lower in the DCM+Astra group than the DCM group. The same effect was found in the in vitro study. These findings showed that astragaloside IV had a potent preventive effect on myocardial fibrosis in CVB3-induced dilated cardiomyopathy that might be due to downregulation of TGF-β1-Smad signaling.     

卡维地洛对柯萨奇病毒B3感染小鼠儿茶酚胺及IL-6表达水平的影响

目的：研究卡维地洛对急性柯萨奇B3（CVB3）病毒性心肌炎小鼠的儿茶酚胺及炎症因子IL-6表达水平的影响。方法： 随机将80只雄性BALB/C小鼠分为3组：正常对照组（n=20）,心肌炎组（n=30）,卡维地洛组（n=30）。后两组经腹腔接种CVB3诱发急性病毒性心肌炎,感染 24 h 后卡维地洛组每日灌胃给予卡维地洛 10 mg/kg,连续 14 d。于接种第7和14天随机从各组抽取8只小鼠取血后处死并留取心脏等标本。比较干预组与对照组心肌病理改变,采用高效液相色谱 电化学法检测去甲肾上腺素含量,采用RT-PCR法检测心肌IL-6mRNA的表达,采用酶联免疫吸附实验方法检测心肌IL-6蛋白的表达。结果：与心肌炎组比较,卡维地洛组心肌病理损伤明显减轻。与正常组比较,病毒性心肌炎小鼠血浆去甲肾上腺素明显升高,卡维地洛干预后小鼠血浆去甲肾上腺素明显下降（P〈0．05）。与正常组比较,心肌炎组心肌IL-6表达明显上调（P〈0．05）。与心肌炎组比较,卡维地洛组IL-6表达明显下调（P〈0．05）。结论：卡维地洛通过抑制儿茶酚胺对心肌的毒性作用以及下调心肌IL-6表达水平,减轻心肌炎小鼠的心肌损害。     

Regulation of inflammation and myocardial fibrosis in experimental autoimmune myocarditis

Autoimmune responses and inflammation are involved in the pathogenesis of many cardiovascular diseases. There is compelling evidence that inflammatory mechanisms may contribute to progressive heart failure. Thus, myocardial infiltration of lymphocytes and mononuclear cells, increased expression of pro-inflammatory chemokines and cytokines and circulating autoantibodies are frequently observed in myocarditis and dilated cardiomyopathy (DCM). Experimental autoimmune myocarditis (EAM) in rodents may be elicited by immunization of cardiac myosin and EAM in rats mimics human fulminant myocarditis in the acute phase and human DCM in the chronic phase. Our animal model, EAM was demonstrated to progress into the clinicopathological state similar to DCM in the chronic phase, and was found to be characterized by the enlargement of the heart, dilatation of ventricles, diffuse and extensive myocardial fibrosis, besides being a cellular immunity and inflammation mediated disease. Severity of myocarditis was characterized by increased inflammation, cardiac fibrosis and decreased myocardial performance in rats with DCM. Pharmacological interventions such as angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARBs) significantly attenuated the myosin-induced inflammation and cardiac fibrosis and thereby improving myocardial function in rats with DCM. A growing body of evidence shows that ACEI and ARBs contribute to the pharmaceutical management of patients with heart failure mediated by immune and inflammatory response. The purpose of this review is to emphasize the role of inflammation and myocardial fibrosis in rats with DCM after EAM and study the effects of pharmacological interventions such as ACEI, ARBs in the treatment of heart failure through the suppression of inflammatory cytokines and fibrosis.     

黄芪三萜皂苷对CVB3诱导病毒性心肌炎的保护作用研究

目的：研究黄芪三萜皂苷（Astragalus saponins,AST）对CVB3病毒诱导病毒性心肌炎的保护作用及机制。方法：利用CVB3病毒、原代心肌细胞及小鼠构建病毒性心肌炎模型并使用AST进行干预,在实验过程中记录小鼠的生存率和体质量变化,体外超声评价小鼠的心脏功能及检测心肌蛋白中LDH和CK-MB水平。心肌组织天狼星红染色评价纤维化水平及TUNNEL染色检测心肌凋亡情况。Western Blot检测心肌蛋白中Caspase-3和Fas表达情况以研究AST保护病毒性心肌炎的机制。结果：AST能够显著增加CVB3注射后的小鼠生存率、缓解CVB3诱导小鼠的体质量减轻。体外超声结果显示,AST能够显著改善CVB3诱导小鼠心脏的收缩功能障碍。CBV3诱导组小鼠心肌蛋白中LDH和CM-KB水平较正常小鼠显著增加,而AST对此有显著的抑制作用。心肌组织病理染色结果显示,AST对CVB3诱导的心肌扩张和纤维化具有显著的保护作用。CVB3诱导组小鼠心肌组织的凋亡水平显著高于正常小鼠,而AST对此有显著的抑制作用。在CVB3感染的心肌组织中,Caspase-3和Fas表达水平显著的升高,而AST能够显著的抑制CVB3诱导的二者在心肌组织中的表达。结论：AST通过提高小鼠的生存率、抑制心肌扩张、心肌组织纤维化和心肌细胞凋亡对CVB3诱导的病毒性心肌炎具有显著的保护作用,这种作用可能与抑制CVB3诱导的Caspase-3和Fas在心肌组织中表达有关。     

蛋白酶体抑制剂MG-132对柯萨奇B3病毒性心肌炎小鼠的作用研究

目的：研究泛素蛋白酶体抑制剂MG-132对柯萨奇B3（CVB3）病毒性心肌炎小鼠的作用,探讨泛素蛋白酶体系统在病毒性心肌炎发病学中的作用机制。方法：随机将80只雄性BALB／C小鼠分为4组（,2—20）：正常对照组、心肌炎组、心肌炎＋处理组、正常＋处理组。腹腔接种CVB3诱发急性心肌炎,次日腹腔注射MG-132,0．75mg／kg;连续给药7d,对照组腹腔注射PBS。第8天小鼠取材,观察心脏病理变化,测定心肌CVB3病毒复制及血清肌钙蛋白、脑钠肽水平。结果：MG-132显著减轻心肌炎小鼠心脏病理损伤,显著降低心脏重量／身体重量比值,MG-132干预后第8天小鼠血清肌钙蛋白、脑钠肽水平显著降低,同时荧光定量PCR显示CVB3mR—NA复制水平显著降低。结论：MG-132通过抑制CVB3病毒复制,显著减轻心肌炎小鼠心脏病理损伤,起到保护心肌作用。     

MYOCARDITIS AS SYSTEMIC DISEASE: NEW PERSPECTIVES ON PATHOGENESIS

1. Myocarditis may be an early indicator of or may subsequently lead to dilated cardiomyopathy in humans. This hypothesis has evolved from research on viruses that induce myocarditis, wherein the coxsackie B group viruses (CVB) in the family Picornaviridae are the most common known viral infectants of heart muscle. 2. Many competing hypotheses exist as to the pathogenesis of CVB3-induced myocarditis, including direct virus-induced myocyte damage and immunopathological disease with autoimmune sequelae. Evidence to support the direct-damage and viral RNA-persistence hypothesis is derived from in situ hybridization and gene amplification studies. 3. Recent use of terminal deoxynucleotidyl transferase-mediated nick-end labelling indicates that this injury in target organs is largely non-apoptotic in nature. Most apoptotic bodies in cardiac tissue are derived from immune cells. 4. Beyond infection of heart muscle, CVB3 can also associate with, infect and persist in cells of immune origin. The CVB3 localizes to follicles in spleens and lymph nodes of the murine host and this particular localization may continue in mice susceptible to more aggressive myocarditis. Whether virus-immune cell association in these compartments is advantageous (or essential) to the host in the evolution of anti-viral immune responses or whether it is more advantageous to the virus in immunosuppression of the host is not known. 5. We suggest that CVB3 can directly perturb or alter the immune response, thereby delaying viral clearance from vulnerable systemic organs. Both host and viral genetic factors can influence susceptibility, persistance and disease progression. 6. Picornaviruses use a unique method for the initiation of translation, involving the internal binding of the ribosome on a sequence element of the 5′ untranslated region, termed an internal ribosome entry sit. (IRES). 7. The IRES of CVB3 is located at approximately stem loops G, H and I, spanning nucloetides 530 and 630. Arrest of host translation is also a feature of picornavirus infection. Such regulation of host cell translation machinery no doubt fosters viral replication at the expense of the host cell. 8. Differences between cell types in the mechanisms, along with those at other key steps in the viral life cycle and in signalling via kinase pathways, may determine viral tropism and cellular destruction and the physiological outcome of neighbourin. cells.     

Selenium and viral virulence

A mouse model of coxsackievirus-induced myocarditis is being used to investigate nutritional determinants of viral virulence. This approach was suggested by research carried out in China which showed that mice fed diets composed of low selenium ingredients from a Keshan disease area suffered more extensive heart damage when infected with a coxsackie B4 virus than infected mice fed the same diet but supplemented with selenium by esophageal intubation. Selenium deficiency in our mice increased the virulence of an already virulent strain of coxsackievirus B3 (CVB3/20) and also allowed conversion of a non-virulent strain (CVB3/0) to virulence. Such conversion of CVB3/0 was accompanied by a change in the viral genome to more closely match that of the virulent virus, CVB3/20. As far as the authors are aware, this is the first report of host nutrition influencing the genetic make-up of an invading pathogen. Nutritionists may need to consider this mechanism of increased viral virulence in order to gain a better understanding of diet/infection relationships.     

卡维地洛和美托洛尔对病毒性心肌炎小鼠IL-12与IFN-γ表达水平的影响

目的：对比研究卡维地洛和美托洛尔对柯萨奇B3（CVB3）病毒性心肌炎小鼠的作用。方法：随机将110只雄性BALB/C小鼠分为4组：正常对照组（n=20）,心肌炎组（n=30）,卡维地洛组（n=30）与美托洛尔组（n=30）。后3组经腹腔接种CVB3诱发急性心肌炎,感染24h后卡维地洛组与美托洛尔组分别每日灌胃给予卡维地洛10mg/kg、美托洛尔30mg/kg,直至第14天末,分别于接种第7天和第14天随机从各组抽取若干只小鼠取血后处死并留取心脏等标本。结果：卡维地洛组显著减轻心脏病理损伤,显著降低心脏重量/身体重量（HW/BW）比值,但美托洛尔组与心肌炎组比较无统计学差异;卡维地洛干预后第7天小鼠心肌IFN-γ与IL-12含量显著升高,MDA含量显著降低,但美托洛尔组与心肌炎组比较无统计学差异;干预后第14天卡维地洛组SOD含量显著增加、MDA含量显著降低,美托洛尔组SOD和MDA含量与心肌炎组比较无统计学差异。结论：卡维地洛通过增加心肌IFN-γ与IL-12表达以及抗氧化损伤的作用,减轻心肌炎小鼠的心肌损害,起到保护性作用,而美托洛尔无类似作用。     

Bifidobacterium as an oral delivery carrier of interleukin-12 for the treatment of Coxsackie virus B3-induced myocarditis in the Balb/c mice

IL-12 plays an important role in the treatment of many infectious diseases by being administered intravenously or intramuscularly. However, intravenous or intramuscular administration is difficult and inconvenient and may cause side effects. The aim of this study is to develop a novel oral delivery system for IL-12 using genetically engineered Bifidobacterium longum as the carrier and further investigate the efficacy of IL-12-expressed B. longum on the coxsackie virus B3 (CVB3)-induced myocarditis in mice. A mIL-12 gene expression vector pBBADs-IL-12 for B. longum was constructed and transformed into Bifidobacterium. Subsequently, the expression of mIL-12 in the engineered B. longum was identified in vitro by western blot and enzyme-linked immunosorbent assay (ELISA) after l-arabinose induction. Moreover, our data indicated that oral administration of IL-12-expressed B. longum for two weeks after CVB3 infection in the Balb/c mice could downregulate the severity of virus-induced myocarditis, markedly reduce the virus titers in the heart and induce a Th1 pattern in the spleen and heart compared with the controls. In conclusion, a novel oral delivery system of Bifidobacterium for murine IL-12 has been successfully established. Oral administration of mIL-12-transformed B. longum may play a therapeutic role in the treatment of CVB3-induced myocarditis in the mice.     

Cardiomyocyte-specific deletion of Senp2 contributes to CVB3 viral replication and inflammation

Viral myocarditis (VMC) is characterized by cardiac inflammation and excessive inflammatory responses after viral infection. SENP2, a deSUMO-specific protease, has been reported to regulate antiviral innate immunity. This study aimed to investigate whether SENP2 affects CVB3-induced VMC. We generated a CVB3-induced VMC mouse model in 6-week-old cardiomyocyte-specific Senp2 knockout mice. The mice were sacrificed at days 0, 2, 4 and 6 after CVB3 infection. The survival rate, body weight, myocardial histopathological changes, viral load, cytokine levels and antiviral gene expression in cardiac tissues of both groups were investigated. Our study indicated that the expression of Senp2 in primary cardiomyocytes was upregulated by CVB3 infection. Moreover, deletion of Senp2 in the heart exacerbated CVB3 infection-induced myocarditis, facilitated CVB3 viral replication and downregulated the expression of antiviral proteins. In conclusion, our findings suggest a protective role for SENP2 in CVB3-induced VMC.     

The comparison of α-bromo-4-chlorocinnamaldehyde and cinnamaldehyde on coxsackie virus B3-induced myocarditis and their mechanisms

Early experiments showed cinnamaldehyde had obvious therapeutic effect on viral myocarditis, but cinnamaldehyde was unstable in vivo. To overcome this limitation, we used cinnamaldehyde as a lead compound to synthesize α-bromo-4-chlorocinnamaldehyde (BCC). In the present study, we compared the therapeutic effects of BCC with cinnamaldehyde on coxsackie virus B3 (CVB3)-induced viral myocarditis (VMC), as well as investigated the possible mechanism. The antiviral and cytotoxic effects in vitro were evaluated on HeLa cells infected by CVB3 and rat cardiomyocytes respectively. Our results showed that IC50 were 0.78±0.13 μM and 48.16±5.79 μM in BCC and cinnamaldehyde-treated cells. 50% toxic concentration (TC) in BCC-treated cells was 22-fold higher than in the cinnamaldehyde group. In vivo BALB/c mice were infected with CVB3 for establishing VMC models. The results demonstrated that BCC reduced the viral titers and cardiac pathological changes in a dose-dependent manner. Myocardial virus titers were significantly lower in the 50 mg/kg BCC-treated group than in cinnamaldehyde groups. In addition, BCC could significantly inhibit the replication of CVB3 mRNA and the secretion of inflammatory cytokines TNF-α, IL-β and IL-6 in CVB3-infected cardiomyocytes. We further observed that BCC suppressed CVB3-induced NF-κB activation, IκB-α degradation and phosphorylation in a concentration-dependent manner, and reduced Toll like receptor (TLR) 4 protein level in hearts. These results suggest that BCC had a promising therapeutic effect on VMC with a highly significant favorable effects and less toxicity than cinnamaldehyde. Furthermore, the effect of BCC on VMC might be through inhibition of inflammatory signaling.     

The antiviral effect of jiadifenoic acids C against coxsackievirus B3

Coxsackievirus B type 3 (CVB3) is one of the major causative pathogens associated with viral meningitis and myocarditis, which are widespread in the human population and especially prevalent in neonates and children. These infections can result in dilated cardiomyopathy (DCM) and other severe clinical complications. There are no vaccines or drugs approved for the prevention or therapy of CVB3-induced diseases. During screening for anti-CVB3 candidates in our previous studies, we found that jiadifenoic acids C exhibited strong antiviral activities against CVB3 as well as other strains of Coxsackie B viruses (CVBs). The present studies were carried out to evaluate the antiviral activities of jiadifenoic acids C. Results showed that jiadifenoic acids C could reduce CVB3 RNA and proteins synthesis in a dose-dependent manner. Jiadifenoic acids C also had a similar antiviral effect on the pleconaril-resistant variant of CVB3. We further examined the impact of jiadifenoic acids C on the synthesis of viral structural and non-structural proteins, finding that jiadifenoic acids C could reduce VP1 and 3D protein production. A time-course study with Vero cells showed that jiadifenoic acids C displayed significant antiviral activities at 0–6 h after CVB3 inoculation, indicating that jiadifenoic acids C functioned at an early step of CVB3 replication. However, jiadifenoic acids C had no prophylactic effect against CVB3. Taken together, we show that jiadifenoic acids C exhibit strong antiviral activities against all strains of CVB, including the pleconaril-resistant variant. Our study could provide a significant lead for anti-CVB3 drug development.KEY WORDS: CVB3, Jiadifenoic acids C, Antiviral activityAbbreviations: CAR, coxsackievirus and adenovirus receptor; CPE, cytopathic effect; CVB3, coxsackievirus B type 3; CVBs, coxsackie B viruses; DAF, decay accelerating factor; DCM, dilated cardiomyopathy; IC₅₀, 50% inhibitory concentration; IRES, internal ribosomal entry site; MOI, multiplicity of infection; NTR, non-translated region; RBV, ribavirin; RdRp, RNA-dependent RNA polymerase; SI, selectivity index; Vero, African green monkey kidney cells     

Effect of prophylactically applied CpG ODN on the development of myocarditis in mice infected with Coxsackievirus B3

Coxsackievirus B3 was one of the major pathogens causing viral myocarditis. Toll-like receptor 9 activation contributed to the innate immune response in the process of CVB3-induced myocarditis. In order to find out how CpG oligodeoxynucleotide, known as a TLR-9 agonist, would affect the CVB3-induced myocarditis, we chose a C-type CpG oligodeoxynucleotide (YW002) injected to the mice one day before CVB3 challenge. On day 4 post CVB3 infection, 3 mice in each group were randomly sacrificed and their hearts were isolated to detect CVB3 replication. On day 10, the CVB3 neutralizing antibody and inflammatory change of the hearts were detected. The results indicated that the CVB3-induced myocarditis was aggravated with the declining body weight of mice, decreasing neutralizing antibody, and uncontrolling virus replication by injecting 20 μg YW002 per mouse. When adjusted the amount at 10 μg YW002 per mouse, there were no signs of aggravation in myocarditis. Plus, the mortality of the infected mice was reduced, the neutralizing antibody level was raised and the replication of virus was restrained. These results suggested that a proper amount of CpG oligodeoxynucleotide application could help to inhibit CVB3 infection.     

Cocaethylene and heart disease during murine AIDS.

Cocaethylene is an active cocaine metabolite believed to play a causative role in the increased incidence of sudden cardiac death in individuals who co-administer alcohol and cocaine. Prolonged and excessive abuse of cocaine and alcohol will result in marked alteration of host immunity to increased susceptibility to infection. To test the chronic direct effect of cocaethylene on the heart function, a conductance catheter system (CCS) was used in vivo in this study. To test whether cocaethylene injection exacerbates coxsackievirus B3 (CVB3) or cytomegalovirus (CMV) cardiomyopathy during murine AIDS, female C57BL/6 mice were infected with LP-BM5 retrovirus and superinfected with CVB3 or CMV. Daily, mice were injected intraperitoneally with cocaethylene in 0.9% saline solution (concentration increased gradually from 15 to 25 mg/ml). Histopathology of heart tissue was analyzed in all groups, and cytokines of spleen were measured in the CMV-infected groups. Results showed there was little effect on the cardiovascular system after cocaethylene injection. Cocaethylene injection during murine retrovirus infection greatly exacerbated the pathogenesis of CVB3 or CMV infection, whereas CMV-infected mice showed relatively moderate cardiac pathology compared with CVB3 infection. Both CMV and retrovirus infection suppressed the Th1 response. Our data suggest that cocaethylene treatment shifts the cytokine balance and suppresses Th1 response particularly, facilitating increased CVB3- or CMV-induced myocarditis.     

Treg responses are associated with PM2.5-induced exacerbation of viral myocarditis

Abstract

The adverse cardiovascular events induced by ambient fine particles (PM_2.5) are paid more attention in the world. The current study was conducted to explore the mechanisms of T regulatory cells (Treg) responses in PM_2.5-induced exacerbation of viral myocarditis. The male BALB/c mice were administered an intratracheal (i.t.) instillation of 10?mg/kg b.w. PM_2.5 suspension. Twenty-four hours later, the mice were injected intraperitoneally (i.p.) with 100?μl of coxsackievirus B3 (CVB3) diluted in Eagle's minimal essential medium (EMEM). Seven days after the treatment, serum, splenetic, and cardiac tissues were examined. The results showed that pre-exposure to PM_2.5 aggravated the cardiac inflammation in the CVB3-infected mice along with an increase of Treg cells in the spleen. The mRNA expressions of interleukin-6 (IL-6), TNF-α, transforming growth factor-β (TGF-β), and Foxp3 were up-regulated in the PM_2.5-pretreated mice than that in the CVB3-treated mice. Similar results were found in the sera. In addition, compared with the CVB3-treated mice, the cardiac protein expression of TGF-β increased in the PM_2.5-pretreated mice. These results demonstrated that preexposure to PM_2.5 exacerbated virus-induced myocarditis possibly through the depression of the immune response and increase of inflammation in myocardium through the Treg responses.     

Antiviral Activity of Chrysin Derivatives against Coxsackievirus B3 in vitro and in vivo

Chrysin is a 5,7-dihydroxyflavone and was recently shown to potently inhibit enterovirus 71 (EV71) by suppressing viral 3C protease (3C^pro) activity. In the current study, we investigated whether chrysin also shows antiviral activity against coxsackievirus B3 (CVB3), which belongs to the same genus (Enterovirus) as EV71, and assessed its ability to prevent the resulting acute pancreatitis and myocarditis. We found that chrysin showed antiviral activity against CVB3 at 10 μM, but exhibited mild cellular cytotoxicity at 50 μM, prompting us to synthesize derivatives of chrysin to increase the antiviral activity and reduce its cytotoxicity. Among four 4-substituted benzyl derivatives derived from C(5) benzyl-protected derivatives 7, 9–11 had significant antiviral activity and showed the most potent activity against CVB3 with low cytotoxicity in Vero cells. Intraperitoneal injection of CVB3 in BALB/c mice with 1×10⁶ TCID₅₀ (50% tissue culture infective dose) of CVB3 induced acute pancreatitis with ablation of acinar cells and increased serum CXCL1 levels, whereas the daily administration of 9 for 5 days significantly alleviated the pancreatic inflammation and reduced the elevation in serum CXCL1 levels. Collectively, we assessed the anti-CVB3 activities of chrysin and its derivatives, and found that among 4-substituted benzyl derivatives, 9 exhibited the highest activity against CVB3 in vivo, and protected mice from CVB3-induced pancreatic damage, simultaneously lowering serum CXCL1 levels.     

Coxsackievirus B3 infection promotes generation of myeloid dendritic cells from bone marrow and accumulation in the myocardium

Myocarditis is associated with increased number of CD4⁺ T cells in the myocardium after coxsackievirus B3 (CVB3) infection. Previous studies show that CD11c⁺ myeloid dendritic cells (mDC) loaded with myosin could induce myocarditis. This study aims to investigate the generation and accumulation of mDC in CVB3-induced myocarditis. The presence of mDC in myocardium was detected by immunohistochemisty. Bone marrow-derived mDC were generated from uninfected and CVB3-infected mice. The percentage of CD11c⁺ mDC on cultured cells and mean fluorescence index (MFI) of double positive cells (CD11c⁺CD40⁺, CD11c⁺CD80⁺) were measured by flow cytometry. The expression of chemokine receptors (CCR5, CCR7) on mDC and chemokines (CCL4, CCL19) in the myocardium was detected. The migration of mDC in response to CCL4 or CCL19 was measured by chemotaxis assay. Mature mDC were elevated in the myocardium from CVB3-infected mice. The percentage of mDC generated from CVB3-infected group was increased. The MFI of CD11c⁺CD40⁺ and CD11c⁺CD80⁺ was increased in CVB3-infected group. The mDC showed a down-regulation of CCR5 and unaffected CCR7 mRAN levels associated with elevated CCL4 and CCL19 in the myocardium in CVB3-infected group. Numbers of migrating bone marrow-derived mDC from CVB3-infected mice were increased in vitro. We conclude that CVB3 infection induced the greater generation of mDC from bone marrow and accumulation of mature mDC in myocardial tissues. This migration was associated with increased levels of both CCL4 and CCL19 in the heart tissue. These suggest that blocking the migration of mDC may provide a novel therapy for myocarditis.     

牛磺酸对培养大鼠心肌细胞感染 Coxsackie B_3 病毒的影响

目的：观察牛磺酸对病毒性心肌炎模型的保护作用。方法：取新生ＳＤ大鼠心室肌制备培养搏动心肌细胞，１８ｈ后接种１００ＴＣＩＤ５０的ＣｏｘｓａｃｋｉｅＢ３病毒（ＣＶＢ３）做为实验性病毒性心肌炎模型。结果：牛磺酸能剂量依赖性地减少感染ＣＶＢ３后心肌细胞乳酸脱氢酶、天冬氨酸氨基转移酶的释放，降低上清液的病毒滴度，对搏动停止、细胞病变及超微结构均有保护作用，并发现感染ＣＶＢ３后心肌细胞内牛磺酸含量下降。结论：临床应用牛磺酸治疗病毒性心肌炎有实验依据。     

Phyllaemblicin B inhibits Coxsackie virus B3 induced apoptosis and myocarditis

Coxsackie virus B3 (CVB3) is believed to be a major contributor to viral myocarditis since virus-associated apoptosis plays a role in the pathogenesis of experimental myocarditis. In this study, we investigated the in vitro and in vivo antiviral activities of Phyllaemblicin B, the main ellagitannin compound isolated from Phyllanthus emblica, a Chinese herb medicine, against CVB3. Herein we report that Phyllaemblicin B inhibited CVB3-mediated cytopathic effects on HeLa cells with an IC₅₀ value of 7.75 ± 0.15 μg/mL. In an in vivo assay, treatment with 12 mg kg⁻¹ d⁻¹ Phyllaemblicin B reduced cardiac CVB3 titers, decreased the activities of LDH and CK in murine serum, and alleviated pathological damages of cardiac muscle in myocarditic mice. Moreover, Phyllaemblicin B clearly inhibited CVB3-associated apoptosis effects both in vitro and in vivo. These results show that Phyllaemblicin B exerts significant antiviral activities against CVB3. Therefore, Phyllaemblicin B may represent a potential therapeutic agent for viral myocarditis.     

氧化苦参碱对病毒性心肌炎小鼠心肌细胞凋亡及相关因子的影响

目的 探讨氧化苦参碱(oxymatrine,OMT)对病毒性心肌炎小鼠心肌细胞凋亡及其凋亡相关因子蛋白表达的影响。方法 42只BALB/c小鼠随机分为正常对照组(NC)、病毒性心肌炎模型组(VM)、OMT高剂量组(OMT-H,25?mg·kg^-1·d^-1)、OMT中剂量组(OMT-M,12.5 mg·kg^-1·d^-1)、OMT低剂量组(OMT-L,6.25 mg·kg^-1·d^-1)、OMT极低剂量组(OMT-EL,3.125 mg·kg^-1·d^-1)、利巴韦林对照组(RB,100 mg·kg^-1·d^-1)。病毒性心肌炎小鼠由柯萨奇病毒B3型腹腔注射感染所致,各治疗组从末次给予病毒24 h后开始,腹腔注射,每日1次。于治疗第12天,每组处死小鼠6只,留取心肌标本。TUNEL法检测心肌细胞凋亡情况,免疫印迹法和免疫组织化学法检测Bcl-2和Bax蛋白的表达情况。结果 OMT治疗显著降低了病毒性心肌炎小鼠凋亡心肌细胞的数量,与病毒性心肌炎模型组比较,OMT-L组效果最佳(P<0.01)。与病毒性心肌炎模型组小鼠比较,OMT治疗组的小鼠心肌组织中Bax蛋白表达降低,而Bcl-2蛋白表达没有明显改变。结论 氧化苦参碱可减少病毒性心肌炎小鼠心肌细胞的凋亡,该作用与下调Bax蛋白表达有关。