Differential expression of capillary VEGF isoforms following traumatic brain injury.

Abstract

OBJECTIVES: While it is known that angiogenesis occurs after trauma, we sought to characterize the expression of vascular endothelial growth factor (VEGF) subtypes, vascular endothelial growth factor receptor 2 (VEGFR2) and angiopoietin within capillaries of animals subjected to traumatic brain injury (TBI). Further, we sought to characterize pericyte cell death in isolated capillaries. METHODS: We used Marmarou's acceleration impact model to induce head trauma and measured VEGF, VEGFR2 and angiopoietin levels in isolated capillaries. TUNEL was used to determine pericyte cell death. RESULTS: The VEGF response was restricted to the VEGF120 isoform. No increase in transcripts for VEGF164 and VEGF188 was observed. VEGFR2 was marginally increased and angiopoietin was increased. A subset of pericytes were TUNEL-positive. DISCUSSION: These results show a distinct expression pattern of angiogenic factors following injury and suggest that pericyte involvement in adaptive angiogenesis may be altered following TBI.