Roles of Sema3A and VEGF165 in cortical neurons and vascular endothelial cells during oxygen glucose deprivation stimulation

To investigate the expressions and roles of semaphorin3A (Sema3A) and vascular endothelial growth factor 165 (VEGF165) in cultured rat cortical neurons and vascular endothelial cells after oxygen glucose deprivation (OGD) stimulation. Cultured cortical neurons (NC) and vascular endothelial cells (VEC) of Sprague Dawley (SD) rats (SPF grade) were randomly divided into control group and OGD treatment group. Western blot assay, immunofluorescent staining and immunohistochemical methods were used to determine the expressions of VEGF165, Sema3A and neuropilin-1 (Nrp-1) protein. Cell migration was determined by Transwell, while TUNEL assay was used to measure apoptosis. The expressions of Sema3A, Nrp-1 and VEGF165 in NC and VEC cells after OGD treatment were up-regulated, when compared with the control group. With transfection of Sema3A shRNA, apoptosis of neurons decreased significantly after 2 h of OGD treatment, but the apoptosis of VEC cells was not obvious. The migration rate of VEC cells in the treatment group was significantly increased, relative to that of the control group. Stimulation with OGD induces neuronal expression of VEGF165 and regulates the migration of vascular endothelial cells, thereby enhancing their participation in angiogenesis, which may involve Sema3A.

Phylogenetic analysis and positive-selection site detecting of vascular endothelial growth factor family in vertebrates

Vascular endothelial growth factor (VEGF), known to play an important role in vascular homeostasis, vascular integrity and angiogenesis, is little known about the evolutionary relationship of its five members especially the role of gene duplication and natural selection in the evolution of the VEGF family. In this study, seventy-five full-length cDNA sequences from 33 vertebrate species were extracted from the NCBI's GenBank, UniProt protein database and the Ensembl database. By phylogenetic analyses, we investigated the origin, conservation, and evolution of the VEGFs. Five VEGF family members in vertebrates might be formed by gene duplication. The inferred evolutionary transitions that separate members which belong to different gene clusters correlated with changes in functional properties. Selection analysis and protein structure analysis were combined to explain the relationship of the site-specific evolution in the vertebrate VEGF family. Eleven positive selection sites, one transmembrane region and the active sites were detected in this process.