| Popis: |
Brazil has experienced an increase in outbreaks caused by flaviviruses. The high incidence of Dengue fever, the morbidity of Zika in children, and the high mortality of yellow fever affected millions in the recent years. Deciphering host-virus interactions is important to treat viral infections, and the mitogen-activated protein kinases (MAPK) are an interesting target because of their role in flavivirus replication. In particular, the mitogen-activated protein kinase kinase (MEK), which targets the extracellular signal-regulated kinase (ERK), is necessary to dengue and yellow fever infections. In this study, we evaluated the role of the MEK/ERK pathway, and the effect of the MEK inhibitor, Trametinib, in ZIKV PE243 Asian strain and the prototype ZIKV MR766 African strain, addressing genome replication, morphogenesis and viral release. ZIKV infection stimulated ERK phosphorylation in Vero cells at 12 and 18 hours post-infection (hpi). Trametinib showed a sustained antiviral activity, inhibiting both ZIKV strains for at least four days and electron microscopy showed a probable inhibition of ZIKV morphogenesis. ZIKV PE243 can complete one cycle in Vero cells in 14 hours: genome replication was detected around 8 hpi, intracellular viral particles at 12 hpi, and extracellular progeny at 14 hpi. Treatments of 6-hour intervals evidenced that Trametinib inhibited late stages of viral replication, and the titration of intra- or extracellular virions showed that the treatment especially affected viral morphogenesis and release. Thus, ZIKV stimulated ERK phosphorylation during viral morphogenesis and release, which correlated with Trametinib inhibiting both, the signaling pathway and the viral replication all together. |
