RESUMEN
[This corrects the article DOI: 10.1038/s42003-018-0226-0.].
RESUMEN
Despite advances in next generation sequencing technologies, determining the genetic basis of ocular disease remains a major challenge due to the limited access and prohibitive cost of human forward genetics. Thus, less than 4,000 genes currently have available phenotype information for any organ system. Here we report the ophthalmic findings from the International Mouse Phenotyping Consortium, a large-scale functional genetic screen with the goal of generating and phenotyping a null mutant for every mouse gene. Of 4364 genes evaluated, 347 were identified to influence ocular phenotypes, 75% of which are entirely novel in ocular pathology. This discovery greatly increases the current number of genes known to contribute to ophthalmic disease, and it is likely that many of the genes will subsequently prove to be important in human ocular development and disease.
RESUMEN
Our previous study demonstrated that vascular endothelial growth factor (VEGF), now referred to as VEGF-A, plays a significant role in blood-brain barrier (BBB) breakdown and angiogenesis after brain injury. In this study, VEGF-A expression was compared with that of VEGF-B in the rat cortical cold injury model over a period of 6 hours to 6 days post-injury. VEGF-A and VEGF-B mRNA were detected by in situ hybridization and their protein was detected by immunohistochemistry. The presence of VEGF-A and VEGF-B proteins in endothelium of lesion vessels was related to BBB breakdown by double labeling for either of these growth factors and fibronectin, which was used as a marker of BBB breakdown. Significant induction of both VEGF-A and VEGF-B mRNA occurred at the lesion site during the period of maximal endothelial proliferation. VEGF-A mRNA levels peaked at 3 and 4 days post-injury and returned to basal expression by day 6, while VEGF-B mRNA levels remained elevated up to day 6. VEGF-B protein was constitutively expressed in endothelium of all cerebral vessels. After brain injury, there was increased immunoreactivity for VEGF-B at the lesion site, this protein being present in the endothelium and vascular smooth muscle cells of pial vessels, in inflammatory cells, and later in proliferating endothelial cells, endothelium of neovessels, and astrocytes. Lesion vessels showing BBB breakdown to fibronectin showed endothelial VEGF-A protein but not VEGF-B protein. Constitutive expression of VEGF-B in normal endothelium suggests that it may have a role in maintenance of the BBB in steady states, while its induction at both the gene and protein level post-injury indicates that it has an essential role in angiogenesis and the repair processes after brain injury.