Silva MiP 2011
|Silva da Costa L, Pereira da Silva AP, Da Poian AT, El-Bacha T (2011) Mitochondrial bioenergetic alterations in mouse neuroblastoma cells infected with Sindbis Virus: Implications to viral replication and neuronal death. MiP2011.|
The metabolic resources crucial for viral replication are provided by host cells. As a result, the utilization of molecules rich in free energy for protein, membranes and viral RNA synthesis needs to be a strict controlled process to ensure viral propagation. The mechanisms by which viruses interact with host energy metabolism, manipulating and driving biosynthetic molecules for their own replication, on the other hand, remain fairly unknown. Accordingly, it was proposed recently that viruses are metabolic engineers because of their ability to alter host energy metabolism to favor replication . Sindbis virus (SinV), the prototype of and most widespread alphavirus, causes outbreaks of arthritis in humans and serves as a model for the study of the pathogenesis of neurological diseases induced by alphaviruses in mice . In this work, respirometric analyses were used to evaluate the effects of SinV infection on mitochondrial bioenergetics of a mouse neuroblastoma cell lineage, Neuro 2a. According to our results, the modulation of mitochondrial function significantly affected cellular ATP content and it was temporally related to viral replication cycle and cell death. At 15h, despite any effects on cell viability, SinV-infected cells presented a slight decrease in Leak respiration and a significant 36% decrease in Electron Transport System (ET-pathway) capacity, which led to a significant 30% increase in the fraction of ET capacity used to drive ATP synthesis. Accordingly, cellular ATP content was not affected by SinV infection. On the other hand, after 24 h of infection, ET-pathway capacity of SinV-infected cells showed a 65% decrease, along with a decrease in the fraction of oxygen consumption used for ATP synthesis when compared to mock-infected cells. These changes were associated with a 30% decrease in cellular ATP content and apoptotic neuronal death. An increase in reactive oxygen species accumulation was observed only after 24h of infection and, therefore, seemed to be a consequence of mitochondrial dysfunction and played a role on neuronal cell death. Taken together these results, it can be concluded that mitochondrial bioenergetics is modulated during the course of SinV infection in such way to favor ATP synthesis required to support active viral replication. These early changes in energy metabolism of Neuro 2a cells may form the molecular basis for neuronal dysfunction and SinV-induced encephalitis.
 Maynard ND, Gutschow MV, Birch EW and Covert MW (2010) The virus as metabolic engineer. Biotechnol J. 5(7):686-94.  Griffin DE and Hardwick JM (1997) Regulators of apoptosis: On the road to persistent alphavirus infection. Annu. Rev. Microbiol. 51:565–92.
Labels: MiParea: Respiration, mt-Medicine Pathology: Cancer Stress:Cell death, Oxidative stress;RONS
Tissue;cell: Neuroblastoma Preparation: Intact cells Enzyme: Complex I, Complex II;succinate dehydrogenase Regulation: ATP production, Inhibitor, Substrate Coupling state: ROUTINE