eNOS and iNOS trigger apoptosis in the brains of sheep and goats naturally infected with the border disease virus.

In this study, apoptotic and anti-apoptotic mechanisms and if present, which pathway to trigger the apoptosis in the brains of Border Disease Virus (BDV) infected lambs (n=10) and goat kids (n=5) were investigated. Briefly, apoptotic (caspase 3, caspase 9) and anti-apoptotic markers (Bcl-2), cytokine response (TNF-α, INF-γ), reactive gliosis and myelin loss were examined. eNOS, iNOS, caspase 9, caspase 3 and GFAP expressions were higher in BDV infected tissues compared to control animals (6 kids and 6 lambs) (p<0.05). Double immunoperoxidase test revealed that TUNEL positive apoptotic cells showed significant association with increased eNOS-iNOS and iNOS-BDV expressions. However, no significant differences were found for TNFR1, TNF-α and INF-γ expressions in BD (p>0.05). There was a positive correlation between the intensity of myelin loss, GFAP activity and severity of infection. Inconclusion, as a novel finding, it is established that eNOS and iNOS overexpressions are co-associated with apoptosis in BDV infected neurons and neuroglia. The results also strongly suggested that BDV infected apoptotic cells mainly prefer the intrinsic pathway that might be most likely related to increased nitric oxide levels.