The role of vascular endothelial growth factor (VEGF) in early brain injury (EBI) after subarachnoid hemorrhage (SAH) remains unclear. The aim of this study was to investigate effects of anti-VEGF therapy on EBI after SAH. C57BL/6 male mice underwent sham or filament perforation SAH modeling, and vehicle or two dosages (0.2 and 1 μg) of anti-VEGF antibody were randomly administrated by an intracerebroventricular injection. Neuroscore, brain water content, immunoglobulin G staining, and Western blotting were performed to evaluate EBI at 24-48 h. To confirm the role of VEGF, anti-VEGF receptor (VEGFR)-2 (a major receptor of VEGF) antibody was intracerebroventricularly administered and the effects on EBI were evaluated at 24 h. A higher dose, but not a lower dose, of anti-VEGF antibody significantly ameliorated post-SAH neurological impairments and brain edema at 24-48 h post-SAH. Post-SAH blood-brain barrier disruption was also inhibited by anti-VEGF antibody. The protective effects of anti-VEGF antibody were associated with the inhibition of post-SAH induction of VEGF, VEGFR-2, phosphorylated VEGFR-2, interleukin-1β and a matricellular protein tenascin-C (TNC). Anti-VEGFR-2 antibody also suppressed post-SAH neurological impairments and brain edema associated with VEGFR-2 inactivation and TNC downregulation. These findings demonstrated that VEGF causes post-SAH EBI via VEGFR-2 and TNC and that anti-VEGF therapy is effective for post-SAH EBI.
Keywords: Antibody neutralization; Blood-brain barrier; Subarachnoid hemorrhage; Tenascin-C; Vascular endothelial growth factor.