Antiapoptotic Mechanism of Insulin in Reoxygenation-induced Injury in Cultured Cardiomyocytes of Neonatal Rats

To examine the protective effect of insulin on reoxygenation-induced injury and explore the underlying mechanisms, the model of anoxia/reoxygenation （A/R） injury was established by inducing anoxia for 2 h and reoxygenation for 4 h in cultured cardiomyocytes of neonatal rats. The rats were randomized to four groups receiving vehicle, insulin, LY294002, insulin plus LY294002 at the onset of reoxygenation after 2 h of anoxia. At the end of reoxygenation of 4 h, activity of lactate dehydrogenase （LDH） and content of malondialdehyde （MDA） were spectrophotometrically determined, apoptosis of cardiomyocytes were detected by using TUNEL and DNA Ladder, and Western blotting was employed to examine the expression of phosphorylated Akt in all groups. Our results showed that compared with vehicle-treated group, activities of LDH, contents of MDA, apoptosis index （AI） were significantly decreased, and expression of phosphorylated Akt was increased significantly in insulin-treated group. However, changes in LDH, MDA, AI and phosphorylated Akt resulting from insulin were attenuated or abolished by LY294002 （PI3K inhibitor）. These data strongly suggest that early administration of insulin at reoxygenation protects cardiomyocytes from reoxygenation-induced apoptosis through PI3K/Akt signaling pathway.     

The effect of oxidative stress in myocardial cell injury in mice exposed to chronic intermittent hypoxia

Background Obstructive sleep apnea syndrome （OSAS） is an important risk factor for cardiovascular diseases. Chronic intermittent hypoxia （CIH） is considered to be one of the most important causes of cardiovascular diseases in OSA patients. This repeated hypoxia and reoxygenation cycle is similar to hypoxia-reperfusion injury, which initiates oxidative stress. In this study, we observed cardiocytes injury induced by CIH and the effect of N-acetylcysteine （NAC）. Methods Thirty ICR mice were randomly assigned to 3 groups： control, CIH and NAC （CIH＋NAC） groups. Malondialdehyde （MDA） and superoxide dismutase （SOD） of cardiocyte homogenates were measured. Serum lipids were measured by an instrument method. Serum cardiac troponin I （cTnl） was detected by enzyme-linked immunosorbent assays （ELISA）. Myocardium pathological sections were observed. Results （1） The SOD activity and MDA concentration of cardiocyte homogenates in the CIH group were significantly higher than in other groups （P 〈0.005）. The MDA concentration of the NAC group was lower than that of the control group （P 〈0.01）. （2） The serum cTnl concentration of the CIH and NAC groups was significantly higher than that of the control group （P 〈0.01）. （3） Serum triglyceride levels in the NAC group were lower than in the other groups （P 〈0.01）, while there were no significant differences in low density lipoprotein and high density lipoprotein among the three groups. （4） The degeneration of myocardium, transverse striation blurred, and fabric effusion were observed in tissue sections in the CIH and NAC groups. However, normal tissue was found in the control group. Conclusion The oxidative stress induced by CIH can injure cardiocytes and the injury effect can be partially inhibited by NAC.     

An experimental study on thymus immune tolerance to treat surgical brain injury

Background Many researches demonstrate that the secondary brain injury which is caused by autoimmune attack toward brain antigens plays an important role in surgical brain injury （SBI）.Although traditional immunosuppression can reduce autoimmune attack,it will lower the body immunity.Immune tolerance,by contrast,not only does not lower the body immunity,but also could lighten autoimmunity.This study used thymus tolerance to develop an immune system that is tolerant to autologous cerebrospinal fluid （CSF） and autologous brain tissue so that autoimmune injury can be suppressed following the disruption of the blood-brain barrier,thereby reducing brain damage.Methods Eighty experimental rabbits were divided into five groups by random number table method：16 in SBI group （group A）,16 in SBI＋CSF drainage group （group B）,16 in SBI＋CSF drainage＋PBS injection group （group C）,16 in SBI＋CSF drainage＋CSF intrathymic injection group （group D）,and 16 in SBl＋brain homogenate intrathymic injection group （group E）.Rabbits＆#39; CSF was drained in group B; was drained and injected PBS into thymus in group C; was drained and injected CSF into thymus in group D; and was injected brain homogenate in group E.Half of the rabbits in each group were phlebotomized on 1st,3rd,7th,and 14th days to observe the changes in IL-I,TGF-β by ELISA test,and CD4CD25 regulatory T cells ratio by flow cytometry,and in other animals brain tissues were taken on 7th day for exploring FasL expression by RT-PCR.The least significant difference （LSD） test was used to make paired comparisons; P ＜0.05 was considered statistically significant.Results The levels of FasL,TGF-β,and the ratios of CD4CD25 regulatory T cells in groups D and E were apparently higher than those in other three groups （P ＜0.05）.Likewise,the levels of IL-1 in these two groups were lower than the other three groups （P ＜0.05）.Moreover,the ratios of CD4CD25 regulatory T cells and the levels of TGF-β in groups B and C were higher than those in group A,but the level of IL-1 was lower than that in group A （P ＜0.05）.There was no significant difference between groups B and C,and groups D and E.Conclusion Thymic injection of CSF and brain homogenate may be able to reduce inflammation after SBI,so thymus immune tolerance may be a useful therapy to treat SBI.     

Role of coxsackievirus and adenovirus receptor in the pathogenesis of dilated cardiomyopathy and its influencing factor

Background Although clinical treatment for heart failure and sudden death has been improved over the last few decades, the morbidity and mortality of dilated cardiomyopathy （DCM） have increased. So a better understanding of the underlying molecular events leading to DCM is urgent. Persistent viral infection （especially coxsackievirus group B3） of the myocardium in viral myocarditis and DCM has never been neglected by experts. Recent data indicate that the up-regulation of coxsackievirus and adenovirus receptor （CAR） in viral cardiomyopathy contributes to viral infection as a key factor in the pathogenesis of this disease. This study aimed to investigate the role and regulatory mechanism of CAR in DCM by the bioinformatic method. Methods We identified the clusters of genes co-expressed with CAR by clustering algorithm based on the public available microarray dataset of DCM （Kittleson, et al. 2005）, and mapped these genes into the protein-protein interaction networks to investigate the interaction relationship to each other at the protein level after confirming that the samples are characterized by the cluster of genes in correctly partitioning. Results The gene cluster GENESET 11 containing 33 genes including CAR with similar expression pattern was identified by cluster algorithm, of which 19 genes were found to have interaction information of the protein encoded by them in the current human protein interaction database. Especially, 12 genes present as critical nodes （called HUB node） at the protein level are involved in energy metabolism, signal transduction, viral infection, immuno-response, cell apoptosis, cell proliferation, tissue repair, etc. Conclusions The genes in GENESET 11 together with CAR may play a pathogenic role in the development of DCM, mainly involved in the mechanism of energy metabolism, signal transduction, viral infection, immuno-response, cell apoptosis and tissue repair.     

Effects of Murine Cytomegalovirus Infection on Sperm Viability in Mice

In order to explore the effects of testicular infection of murine cytomegalovirus （MCMV） on mature sperm viability at different periods following MCMV inoculation in mice, 91 BALB/c mice without MCMV infection were randomly divided into two groups： an experimental group （n= 56） and a control group （n=35）. The mice in the experimental group were treated by inoculating MCMV intratesticularly, while those in the controlled group were directly inoculated with DMEM without MCMV. The mice in both groups were sacrificed separately on the day 1,1.5, 2, 4, 6, 9 and 14 post-inoculation （D1, 1.5, 2, 4, 6, 9 and 14 PI）. The MCMV M83 mRNA gene was detected in the testis by in situ hybridization （ISH） with MCMV late-mRNA probe labeled with digoxin. Sperm viability of mature sperm in the epididymis cauda was measured. The results demonstrated the positive signal of ISH of MCMV was found mainly in the cytoplasm of the testicular interstitial cells and spermatogenic cells in the experimental group. Compared with that in the controlled group, the sperm viability in the experimental group was decreased significantly on D1 PI and D1.5 PI （P〈 0.05）. No statistically significant difference in the sperm viability was found after D2 PI between two groups （P〉0.05）. This suggested that sperm viability in mice might be descended significantly shortly after MCMV infection and might return to normal with time, indicating that MCMV acute infection might temporarily degrade sperm quality and influence procreation transiently.     

Influence of silencing soluble epoxide hydrolase with RNA interference on cardiomyocytes apoptosis induced by doxorubicin

In order to investigate the influence of silencing soluble epoxide hydrolase(sEH) with double-stranded small interfering RNA(siRNA) on cardiomyocytes apoptosis induced by doxorubicin(DOX),two plasmids containing siRNA sequences specific to sEH were constructed and transfected into the primary cultured cardiomyocytes by using FuGENE HD transfection agents.The mRNA and protein expression levels of sEH were detected by semiquantitative RT-PCR and Western blotting respectively,and the plasmids that silenced sEH most significantly were selected,and renamed EH-R.The plasmids carrying a nonspecific siRNA coding sequence(PCN) served as the negative control.Cardiomyocytes were divided into four groups:control group,DOX group,PCN+DOX group,and EH-R+DOX group.Apoptosis of cardiomyocytes was induced by DOX at a concentration of 1 μmol/L.Apoptosis rate of cardiomyocytes was determined by flow cytometery.The protein expression levels of Bcl-2 and Bax were detected by Western blotting.The results showed that the expression of sEH was down-regulated by EH-R plasmid.The expression levels of sEH mRNA and protein in the EH-R+DOX group were significantly decreased as compared with other groups(P<0.01).As compared with the control group,the apoptosis rate of cardiomyocytes in three DOX-treated groups was obviously increased,the expression levels of Bax increased,and those of Bcl-2 decreased(P<0.01).However,the expression levels of Bax were decreased,those of Bcl-2 increased and the apoptosis rate of cardiomyocytes obvi-ously decreased in EH-R+DOX group when compared with those in the DOX group and the PCN+DOX group(P<0.01 for each).It was concluded that the recombinant plasmids could be successfully constructed,and transfected into the primary cultured cardiomyocytes.They could ameliorate the DOX-induced cardiomyocytes apoptosis by selectively inhibiting the expression of sEH with RNAi and increasing the expression of Bcl-2.     

EFFECT OF COXSACKIEVIRUS B3 ON ION CHANNEL CURRENTS IN RAT VENTRICULAR MYOCYTES

Objective. To investigate the effects of coxsackievirus B3 ( CVB3 ) on ion channel currents in rat ventricular my-ocytes. Methods. Rat hearts were isolated with collagenase to acquire single ventricular myocytes, L-type voltage-depen-dent calcium channel( VDCC) current (ICa),Na^ current (INa), outward potassium current (Iout), inwardly rectifying potassium current(IKI) were recorded using whole cell patch clamp techniques. Results. CVB3 infection increased Ica and Iout, while decreased IKI; but it had no obvious effect on INa. Conclusion. The effects of CVB3 on ICa,Iout, IKI may be one of the mechanisms of myocytes damage and the oc-currence of abnormal electroactivities induced by CVB3 infection.     

PROTECTIVE ROLE OF SOPHOCARPINE IN COXSACKIEVIRUS B3 INFECTION IN CULTURED RAT CARDIOMYOCYTES

Coxsackievirus B3(CVB3) has been identifiedas the major causative agent of the viral myocarditisand dilated cardiomyopathy. The direct injury of thevirus and the immuno-induced injury are the twomechanisms causing the inflammation of the myocar-dium. A se…     

槐果碱体外抗柯萨奇病毒B3m的作用

目的以HeLa细胞为模型,观察从苦参中提取的槐果碱在体外抗柯萨奇病毒B3m(CVB3m)的作用。方法①用微量细胞培养法观察槐果碱对HeLa细胞的毒性。②用细胞病变效应(CPE)抑制法观察槐果碱体外抗CVB3m作用。③用MTT法和结晶紫染色法观察槐果碱对CVB3m感染的HeLa细胞的保护作用:在96孔板上种植HeLa细胞并予CVB3m吸附1h,加入不同浓度的槐果碱,并设立病毒、细胞、槐果碱对照,培养15h后以MTT法和结晶紫染色法测定比较各组细胞能量代谢率和细胞存活数。结果①槐果碱稀释到<391μg/mL,对HeLa细胞无毒性;≥783μg/mL引起HeLa细胞CPE。②槐果碱6.25~50μg/mL有直接抗病毒作用,减轻CPE;>100μg/mL反而会加重、加快CPE。③槐果碱1.56~25μg/mL对感染CVB3m的HeLa细胞有保护作用,用MTT法和结晶紫染色法测得细胞能量合成代谢、细胞存活数较病毒对照组增加(P<0.05);槐果碱在50、100μg/mL时反而加重病毒对细胞的抑制,使细胞存活数、细胞代谢率较病毒对照组下降(P<0.05)。结论一定浓度的槐果碱在体外有抗CVB3m作用,对感染CVB3m的HeLa细胞有保护作用。     

Effect of Prevention and Treatment of Murine Acute Viral Myocarditisand Protection of Lymphoid Organ Atrophy withXinkang Oral Liquid (心康口服液)

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病毒性心肌炎致病机理的实验研究：组织病理和心电图观察

BALB/C小鼠注射柯萨奇B3病毒(CVB3m)后,第2天出现病毒血症,并从心肝肾脑等脏器分离出病毒,肝组织呈肝炎或重症肝炎病理图象,第5天抗体产生,病毒血症终止,除心脏外,其它脏器中病毒消失。病理检查可见心肌坏死,第8,9天,心肌坏死达高峰,心肌内病毒、循环抗体消失。心肌超微结构显示线粒体、心肌纤维、心肌组织等进行性病变。89%(54/63)的小鼠种毒后第3天开始出现心电图改变,主要表现在P波倒置,QRS时间延长,房室传导阻滞和出现异常Q波。心电图检测的成功,对利用动物模型进行致病机理、免疫,药物治疗等研究提供了方便。     

柯萨奇B3病毒性心肌炎模型小鼠的免疫学指标检测

目的：建立急性病毒性心肌炎小鼠模型并检测其免疫功能指标。方法：腹腔注射CVB3建立急性病毒性心肌炎小鼠模型，用MTT比色法检测NK、TNF、IFN的活性；进行小鼠心肌组织病毒分离、病理检查，检测小鼠体重、心脏及脾脏重量变化。结果：CVB3感染鼠的体重及心脏、脾脏的重量均明显减轻；血清中TNF活性及脾细胞诱生TNF量显著增高；脾脏NK活性增高，但脾细胞诱生IL－2量降低；IFN无明显变化。结论：急性病毒性心肌炎模型小鼠的NK活性、细胞因子等指标均发生明显变化。     

复方羌芪水提液体外抗柯萨奇病毒B3作用的研究

目的：测定复方羌芪水提液的体外抗ＣＶＢ３作用，并对其抗病毒机理进行初步的探讨。方法：用含有不同浓度复方羌芪水提液的维护液培养ＣＶＢ３感染的Ｖｅｒｏ细胞，４８ｈ后用ＭＴＴ法测定细胞活性；培养上清液滴定ＴＣＩＤ５０。结果：复方氏水提液能抑制ＣＶＢ３对Ｖｅｒｏ细胞的致病变作用（ＣＰＥ），使细胞夏活率升高，培养上清病毒滴度降低；且随药物浓度及药物与病毒作用时间的延长抑制作用增强。结论：复方羌芪水提液的抗病     

成人病毒性肝炎患者柯萨奇病毒感染研究

目的 :探讨成人病毒性肝炎患者中柯萨奇病毒B组 (CoxsackievirusB ,CVB)散发性感染状况。方法 :用ELISA法测定病毒性肝炎患者血清中抗CVB -IgM抗体 ,同时应用荧光定量PCR方法测定HBVDNA及HCVRNA含量。结果 :4 5 7例病毒性肝炎患者中抗CVB -IgM阳性 13例 ,其中CVB单独感染者 1例。CVB感染组与阴性对照组在临床表现、肝功能试验、HBVDNA含量等方面相比无明显差异。结论 :病毒性肝炎患者中CVB感染率为 2 .84 % ,其肝炎病原学意义有待进一步研究     

柯萨奇病毒B3的多克隆抗体制备

目的制备柯萨奇病毒B3(coxsackievirus B3,CVB3)的多克隆抗体。方法针对CVB3基因的VP1区设计特异性引物,RT-PCR扩增VP1基因并将其克隆到pGEX-6p-1中,经IPTG诱导表达后,以GST-VP1融合蛋白作为抗原免疫新西兰大白兔,制备多克隆抗体。采用ELISA、Western blot以及间接免疫荧光检测多克隆抗体的效价和特异性。结果 ELISA检测血清的效价不低于1∶64 000,Western blot和间接免疫荧光显示该抗体具有良好的特异性。结论成功制备了效价较高的CVB3多克隆抗体,可应用于CVB3蛋白的检测。     

Antiviral effects of aqueous extract from Spatholobus suberectus Dunn. against coxsackievirus B3 in mice

Objective  

To investigate the antiviral effects of the aqueous extract of Spatholobus suberectus Dunn. (A.E.), a Chinese medicinal herb, against coxsackievirus B3 (CVB3).