The Effects Of P53on WRD Cell Apoptosis Induced By MVC Virus Infection

Object MVC (Minute Virus of canine) is a member of Bocavirus family. Our group hasdiscovered previously that DNA damage, cell apoptosis and cell cycle arrest could be inducedafter MVC infection. However, the relative pathways of apoptosis by MVC induced are notclear so far. Therefore, the expression changes of p53and its downstream target genes and theintervention effect of p53inhibitor were detected in WRD cell infected by MVC virus in thisstudy, so as to investigate the effects of p53on WRD cell apoptosis after MVC infection.Method Firstly, cell morphological changes were observed after Bocavirus MVC infectedWRD; The cell apoptosis was detected and analyzed through TUNEL assays; The effect ofp53inhibitor on cell viability and target cell apoptosis during cell infection were observed byMTT assays and flow cytometry analysis. Based on the results of p53in cell apoptosis,mRNA expression of p53was detected by PCR and Real-time PCR, and p53protein levelexpression was detected by Western blot. Furthermore, the phosphorylation level of p53andthe downstream P21, FAS-L expression levels were also analyzed by Western blot.Result1. The cell apoptosis bodies were observed obviously in the infected cells by usingTUNEL assay.2. In the detection of p53mRNA level, PCR results showed that p53expression was increased clearly on12h after infection, and P53protein was also increased bywestern blot detection, consistent with the results of p53mRNA level.3. P53-Ser15and P21expressions were increased along with the MVC infection. While the FAS-L expression wasnot obviously changed during all period of MVC infection.4. The cell vitality in p53inhibitorintervention group was higher than that of the non-intervention group by using MTT assay.5.The flow cytometry analysis showed that p53inhibitor could decrease cell apoptosis inducedby MVC infection.Conclusions With cytopathic effect of WRD cell induced by MVC, both mRNA and protein expression levels of p53were increased, and P53phosphorylation was also enhanced. TheP53expression induced by MVC could promote the p21expression, regulated by p53. MVCinfection did not induce the expression change of FAS-L in WRD cells, indicating that deathreceptor pathway may not intervene in the MVC induced apoptosis process. P53inhibitorcould decrease apoptosis level of the target cell WRD induced by MVC infection. In summary,p53has involved in apoptosis process of the target cell WRD induced by MVC infection.