Unfortunately, there are no animal models with which to study activation of BKV replication in the human kidney and the accompanying PVAN. Here we report studies of the restriction of BKV replication in murine cells and extracts and the cause(s) of this restriction. Upon infection of murine cells, BKV expressed DNA Damage inhibitor large T antigen (TAg), but viral DNA replication and progeny
were not detected. Transfection of murine cells with BKV TAg expression vectors also caused TAg expression without accompanying DNA replication. Analysis of the replication of DNAs containing chimeric BKV and murine polyomavirus origins revealed the importance of BKV core origin sequences and TAg for DNA replication. A sensitive assay was developed with purified BKV TAg that supported TAg-dependent BKV DNA replication with human but not with murine cell extracts. Addition of human replication
proteins, DNA polymerase alpha-primase, replication protein A, or topoisomerase I to the murine extracts with BKV TAg did not rescue viral DNA replication. Notably, addition of murine extracts to human extracts inhibited BKV TAg-dependent DNA replication at a step prior to or during unwinding of the viral origin. These findings and differences in replication specificity between BKV TAg and the TAgs of simian virus 40 (SV40) and JC virus (JCV) and their respective origins implicate features of the BKV TAg check details and origin distinct from SV40 and JCV in restriction of BKV replication in murine cells.”
“The rat’s prefrontal cortex plays a role in integration of feeding-related information. In this study, we investigated the neuronal activity changes of medial
prefrontal cortex during licking of sucrose solution by freely moving rats. We found two Isoconazole different types of excitatory and two different types of inhibitory single neuron responses time locked to the beginning of the licking clusters. Changes in firing rates occurred either within 2 s before the first lick of the licking cluster or during the licking cluster. These observations suggest that neuronal responses in the medial prefrontal cortex may represent anticipation and consummation of liquid food reward. NeuroReport 20:1235-1239 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.”
“The p38 and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs) play important roles in the host innate immune response. The protein kinase regulated by RNA (PKR) is implicated in p38 MAPK activation in response to proinflammatory signals in mouse embryonic fibroblasts. To test the role of PKR in the activation of p38 and JNK MAPKs in human cells following viral infection, HeLa cells made stably deficient in PKR by using an RNA interference strategy were compared to cells with sufficient PKR.