Background: Vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1) can promote angiogenesis and vascular stability after brain injury. Circulating endothelial progenitor cells (EPCs) also play a crucial role in neovascularization and tissue repair after traumatic brain injury (TBI). We sought to compare the expression of VEGF and Ang-1 in serum and the circulating EPCs in patients after severe TBI with that of healthy control subjects.
Methods: We obtained peripheral blood and serum samples from 21 patients with severe TBI and 11 healthy control subjects. EPCs in blood samples from severe TBI patients and healthy controls were quantified by flow cytometry 1 day, 4 days, 7 days, 14 days, and 21 days after severe TBI. VEGF and Ang-1 were measured by enzyme linked immunosorbent assay at the same time points.
Results: Compared with control subjects, circulating EPCs in patients with severe TBI decreased 4 days (p < 0.05), but increased 7 days and 14 days (p < 0.05) after TBI. VEGF increased significantly during the follow-up period (p < 0.05). Ang-1 increased gradually and reached peak at 7 days and 14 days after TBI. The circulating EPCs were significantly correlated with VEGF and Ang-1 at 7 days and 14 days after severe TBI.
Conclusions: Our results suggest that the increased VEGF and Ang-1 are closely related to increase in circulating EPCs in response to severe TBI, which may be needed for vascular repairs after severe TBI.