B组柯萨奇病毒诱导的细胞焦亡在心肌损伤中的作用

Coxsackievirus B causes myocardial injury through inducing pyroptosis

目的利用caspase-1抑制剂抑制焦亡，评价细胞焦亡在B组柯萨奇病毒（Coxsackievirus B，CVB）所致心肌损伤中的作用，确定CVB能否通过诱导细胞焦亡导致心肌炎症。方法Balb/c乳鼠分为四组：对照组、CVB3感染组（腹腔注射CVB3）、1次抑制剂组（CVB3感染乳鼠后注射1次caspase-1抑制剂）和3次抑制剂组（CVB3感染乳鼠后在1、3、5天分3次注射caspase-1抑制剂），Western blot检测各组乳鼠心肌组织中的caspase-1表达，HE染色观察各组乳鼠心肌组织病理变化。HeLa细胞分为8组，前4组用CVB3感染不同时间，后4组CVB3感染的同时分别加入不同剂量caspase-1抑制剂，检测CVB3病毒蛋白表达量。结果CVB3感染组的乳鼠心肌组织中激活的caspase-1含量增加，与CVB3组相比，注射caspase-1抑制剂的小鼠心肌组织中激活的caspase-1含量明显减少。正常对照组乳鼠心肌细胞组织状态正常，CVB3感染组乳鼠心肌组织大面积变性、坏死，CVB3＋caspase-1抑制剂组乳鼠心肌组织发生病理变化但程度较轻。HeLa细胞中caspase-1与CVB3蛋白含量随caspase-1抑制剂剂量增大而降低。结论抑制细胞焦亡可有效减轻CVB3所致心肌损伤，CVB诱导的焦亡参与心肌致病过程。

ObjectiveTo observe the effect of pyroptosis in the myocardial injury caused by Coxsackievirus B （CVB）, and to determine whether CVB cause myocardial inflammation through pyroptosis.MethodsNewborn Balb/c mice at the age of 3 days were divided into 4 groups： control groups; infected with CVB type 3 （CVB3） intraperitoneally; treated with Ac-YVAD-CMK intraperitoneally once at the same time of viral inoculation, or three times at 1, 3, 5 days after CVB3 infected.The expression level of caspase-1 protein was determined by Western blotting.The myocardial injury of the treated mice was observed with HE section.HeLa cells were divided into eight groups： four groups were infected with CVB3 for various time periods while the other four groups were infected with CVB3 and treated with various doses of caspase-1 inhibitor.ResultsCVB3 infection induced caspase-1 activation in cardiac muscle.Compared with the mice infected with CVB3 alone, the treatment of caspase-1 inhibitor markedly reduced the level of cleaved caspase-1.Caspase-1 inhibitor also suppressed CVB3 replication as shown in Hela cells.The myocardium of the mice treated with caspase-1 inhibitor after CVB3 infection showed slightly inflammation and necrosis compared with mice infected with the virus only.ConclusionSuppression of pyroptosis can effectively relieve themyocardial injury.The pyroptosisplays a pathological role in the CVB-related myocardial diseases.