硫化氢对柯萨奇病毒感染的病毒性心肌炎小鼠的保护作用

The protective role of hydrogen sulfide in a mouse model of viral myocarditis induced by Coxsachie-virus B3

目的研究硫化氢对柯萨奇病毒B3（Coxsachievirus B3， CVB3）感染的病毒性心肌炎小鼠的保护作用以及胱硫醚γ-裂解酶（ CSE）/硫化氢（ H2 S）通路在其体内的表达情况。方法将110只5周龄的雄性BALB/c小鼠随机分为4组：正常对照组、病毒性心肌炎组、硫氢化钠（外源性H2 S供体）组和DL-炔丙基甘氨酸（ PAG，CSE不可逆抑制剂）组。以腹腔注射CVB3建立急性病毒性心肌炎模型，接种当天记为第0天，24 h后每组每日经腹腔分别注射相应干预药物。分别于接种后第4天和第10天从各组随机抽取10只处死，留取血清和心肌标本。观察心肌炎症病理改变，酶联免疫吸附法检测H2 S及IL-6、TNF-α等炎症因子含量，逆转录-聚合酶链反应法检测心肌组织CVB3、CSE的mRNA表达水平，免疫组化及蛋白质印迹法定性、定量检测CSE蛋白水平表达。结果与正常对照组比较，病毒性心肌炎组血清和组织H2 S浓度、CSE mRNA、CSE蛋白水平表达均明显下调，给予NaHS干预可明显上调H2 S水平，减轻心肌损伤、减轻炎症细胞浸润以及间质水肿，对病毒CVB3 mRNA的表达有抑制作用，而给予PAG干预，可明显抑制H2 S和CSE表达，加重心肌损伤、炎症细胞浸润及间质水肿，促进CVB3 mRNA的复制。结论在病毒性心肌炎中，CSE/H2 S通路表达明显受到抑制，给予PAG干预可明显抑制该通路的表达，加重心肌损伤，促进病毒复制，外源性供给硫化氢可对感染心肌起到保护作用，且可抑制病毒复制。

Objective To investigate the protective role of hydrogen sulfide and the expression of cystathionine gamma-lyase/hydrogen sulfide pathway in a mouse model of myocarditis induced by Coxsachie -virus B3（CVB3）.Methods A total of 110 five-week-old BALB/c male mice were randomly divided into four groups：the control group, viral myocarditis group, sodium bisulfide （NaHS） group （50 μmol/kg） and DL-propargylglycine （PAG） group （40 mg/kg）.The experimental model of viral myocarditis was induced by intraperitoneal injection of CVB 3.Then the four groups were respectively administered with PBS , PBS, NaHS and PAG from day 1 to day 10 after infection.Blood and heart specimens were harvested from 10 mice of each group on day 4 and day 10 for evaluation of myocardial edema .The pathological changes in heart tis-sues were observed through hematoxylin-eosin staining.Levels of H2 S, IL-6 and TNF-αwere measured by ELISA.The expressions of CSE and CVB 3 at mRNA level were determined by quantitative real time PCR （ qRT -PCR ） analysis and the expression of CSE at protein level was detected by Western blot .Results Compared with the control group , the levels of H2 S and the expressions of CSE at mRNA and protein levels were down-regulated in mice with CVB 3-induced myocarditis .With the treatment of NaHS , the levels of H 2 S in serum and tissue were both up-regulated , and the histopathological damage was alleviated .However , PAG as an irreversible CSE inhibitor inhibited the expressions of H 2 S and CSE and aggravated myocardial injury , inflammatory cells infiltration and interstitial edema .Moreover , the RT-PCR analysis also showed that the＆nbsp;expression of CVB3 at mRNA level was inhibited by NaHS but enhanced by PAG .Conclusion The expres-sion of CSE/H2 S pathway is down-regulated in mice with CVB 3-induced viral myocarditis .PAG could pro-mote virus propagation and exacerbate the disease through inhibiting the production of endogenous H 2 S, while NaHS as a H2 S donor has a protective effect on infected myocardium by suppressing virus replication at an early stage .