Influence of cytochrome c on apoptosis induced by Anagrapha (Syngrapha) falcifera multiple nuclear polyhedrosis virus (AfMNPV) in insect Spodoptera litura cells.
We investigated the influence of cytochrome c on apoptosis induced by Anagrapha (Syngrapha) falcifera multiple nuclear polyhedrosis virus (AfMNPV). Microscopic observation revealed that infection of SL-1 cells with AfMNPV resulted in apoptosis, displaying apoptotic bodies in fluorescent-stained nuclei of AfMNPV-infected SL-1cells. Western blot analysis demonstrated that AfMNPV-induced apoptosis in insect SL-1 cells was significantly inhibited by cyclosporin A which blocked a translocation of cytochrome c from the mitochondria to the cytosol. As determined by using AC-DEVD-AFC as substrate, the activity of caspase-3 in AfMNPV-induced cells was detected as early as 4h post infection, gradually increased with time extension, and reached a highest level after 16h of infection. However, activity of caspase-3 in apoptotic cells decreased in the presence of cyclosporin A (30microM), indicating that activation of caspase-3 in SfaMNPV-induced cells was dependent on the release of cytochrome c from the mitochondria. In addition, cyclosporin A could markedly inhibit mitochondrial transmembrane potential (DeltaPsim) disruption in undergoing apoptotic cells. These data indicate that cytochrome c plays a key role in AfMNPV-induced apoptosis in S. litura cells and may be required for caspase activation during the induction of apoptosis.
Liu
Lijun
L
Institute of Entomology, Ministry of Education, Central China Normal University, Wuhan 430079, China.
Peng
Jianxin
J
Liu
Kaiyu
K
Yang
Hong
H
Li
Yi
Y
Hong
Huazhu
H
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D016572:Cyclosporine / Q000494:pharmacology; D045304:Cytochromes c / Q000378:metabolism*; D004249:DNA Damage; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D017924:Nucleopolyhedroviruses / Q000502:physiology*; D018411:Spodoptera / Q000166:cytology* / Q000187:drug effects / Q000821:virology*
D016572:Cyclosporine; D045304:Cytochromes c; D053148:Caspase 3