Activation of the Mitochondrial Apoptotic Signaling Platform during Rubella Virus Infection

Claus, Claudia; Manssen, Lena; Hübner, Denise; Roßmark, Sarah; Bothe, Viktoria; Petzold, Alice; Große, Claudia; Reins, Mareen; Mankertz, Annette; Frey, Teryl K.; Liebert, Uwe G.

Viruses 2015, 7, 6108-6126 Thereafter, the mRNA expression level of Cyp40 was determined to verify whether this massive shift of Cyp40 to the nucleus was also associated with an increase in Cyp40 protein synthesis. Figure 6C indicates that the mRNA expression level of Cyp40 at 1 (96%¨31%) and 3 dpi (136%¨40%) in RV-infected Vero cells was comparable to the mock-infected population (set as 100%). However, at 2 dpi an increase in the mRNA expression level of Cyp40 was detectable (219%¨61%). Taking the influence of RV on p53 intracellular distribution into account, different stress stimuli were applied and subjected to immunofluorescence analysis, such that it could be determined whether a co-activation mechanism between these two proteins exists. Figure 6F shows that both heat shock and incubation with 0.003% hydrogen peroxide induced a shift of Cyp40 and p53 to the nucleus. The application of both camptothecin (CPT) and cycloheximide (CHX) reflects that nuclear As a next step, the effect of NIM811 (2 µM at 2 hpi) and PFTµ (12.5 µM at 24 hpi) on Cyp40 distribution was investigated. Neither the application of NIM811 nor PFTµ had a noticeable influence on Cyp40 distribution in mock-infected Vero cells, shown in Figure 6D which is representative of the SC-treated mock population. Under RV infection, Cyp40 distribution after application of PFTµ is comparable to the SC-treated population. NIM811 appears to have a minor, but negligible effect on Cyp40 distribution. Western blot analysis of nuclear fractions ( Figure 6E ) confirmed results obtained by the immunofluorescence analysis ( Figure 6D ).