The Effect Of Cardiac Mast Cells And TLR4to The Pathogenesis Of VMC In Mice

Objective:Explore the role and pathogenesis mechanism of mast cells and TLR4in the occurrence and development process of viral myocarditis.Methods:Coxsackie virus B3(CVB3) was intrapertoneal injected into BALB/C mice to creat the viral myocarditis models(model group,n=24). Control mice was intrapertoneal injected with virus-free Eagle’s solution (control group,n=24). Observe the general situation of the two groups of mice. Mice cardiac tissues were stained by HE,Masson and transmission electron microscopy to observe the pathological changes after inoculated with the virus7、14、28days, stained by Toluidine-blue and used transmission electron microscopy to observe the mast cells. The expression of TLR4was measured by immunohisto-chemistry and RT-PCR. Analyze the relationship of mast cells and TLR4mRNA of the model group.Results:1.The establish of VMC model:after intraperitoneal injected with CVB3, the mice of model group performed the changes of general behavior like hair loss and weight loss。 The HE staining showed that the model group had myocardial edema and necrosis, each time of the model group, the pathological scores were higher than the control group (P<0.05)。Masson staining showed that there were a lot myocardial interstitial and perivascular collagen deposition of the model group were on days28, and the CVF were higher than that of the model group on days7、14and the control group (all P<0.05)。The transmission electron microscopy showed that the myocardial arrangement were disorderly, and the myocardial nuclers were out of shape。2.The number and the shape of mast cells:the toluidine blue staining showed that the number of mast cells was increased in the model group. and the difference was statistically significant(P<0.05); And the transmission electron microscopy showed that the degranulation of mast cells were more signifucant than the control group. 3.The expression of TLR4:The immunohistochemical staining and RT-PCR showed that each time of model group,the myocardial positive area of TLR4expression and TLR4mRNA expression were upregulated than that of the control group, the difference was statistically significant(P<0.05);4.Each time the expression of the number of mast cells and TLR4mRNA of model group were correlated positively(R2=0.877, P<0.05).Conclusion:That mast cells and TLR4play an important role in inflammatory reaction and fibrosis of VMC. Cardiac mast cells and TLR4may promote mutually in the development process of VMC in mice.