Contact repulsion of growing axons is an essential mechanism for spinal nerve patterning. In birds and mammals the embryonic somites generate a linear series of impenetrable barriers, forcing axon growth cones to traverse one half of each somite as they extend towards their body targets. This study shows that protein disulphide isomerase provides a key component of these barriers, mediating contact repulsion at the cell surface in chick half-somites. Repulsion is reduced both in vivo and in vitro by a range of methods that inhibit enzyme activity. The activity is critical in initiating a nitric oxide/S-nitrosylation-dependent signal transduction pathway that regulates the growth cone cytoskeleton. Rat forebrain grey matter extracts contain a similar activity, and the enzyme is expressed at the surface of cultured human astrocytic cells and rat cortical astrocytes. We suggest this system is co-opted in the brain to counteract and regulate aberrant nerve terminal growth.
Current re-emergence of Nipah virus (NiV) in India caused 11 deaths so far and many patients were kept in quarantine. A thorough study of previous outbreaks occurred in Malaysia, Bangladesh and India represents cases with high rate of fatality due to acute encephalitis. Our work involves genome analysis of NiV for prediction of miRNAs and their targeted genes in human in order to understand encephalitis origin. Ab-intio program-VMir was used for initial screening of genome, obtained nine pre-miRNAs was analyzed by ViralMir to check for any pseudo pre-miRNAs. Eighteen functional mature miRNAs were extracted from pre-miRNAs by using Mature-Bayes tool, which targets 669 genes in human genome as retrieved by miRDB. Gene ontology terms by PANTHER provide important pathways in which target genes were involved like Axon guidance, T cell activation, and nicotinic acetylcholine receptor signaling. Significant outcome was obtained after NCBI Gene and OMIM database mining and literature search for predicted target genes. TLR3, TJP1, NOTCH2, FHL1, and GRIA3 target genes obtained showed their involvement in host defense, blood brain barrier, neurogenesis, mental retardation and encephalitis. To conclude, we predicted significant genes in human that can be inhibited by miRNAs of NiV and results in etiology of encephalitis.