Negative correlation of CD34+ cells with blood-brain barrier permeability following traumatic brain injury in a rat model.

Abstract

TBI causes localized cerebral ischemia that, in turn, is accompanied by both changes in BBB permeability and recruitment of CD34(+) cells to the injured tissue. However, it remains unknown whether CD34(+) cell recruitment is linked to BBB permeability. This study is a preliminary investigation into possible correlations between CD34(+) cell recruitment and BBB permeability following TBI in a rat model. Male SD rats were subjected to mild fluid percussion injury. BBB permeability was assessed by measuring extrinsic EB dye extravasation and endogenous EBA expression at days 1, 3, 5, 7, and 12 post injury. The number of CD34(+) cells in the damaged tissue was analyzed by immunohistochemistry at each time point. EB dye extravasation reached a peak at day 3 following TBI, while EBA expression displayed the reverse profile. Accumulation of CD34(+) cells in injured brain tissue was evident at five days post injury. It revealed a negative linear correlation between CD34(+) cell and BBB permeability. The negative linear correlation between CD34(+) cell recruitment and BBB permeability following TBI provides a support for further study of CD34(+) cell transplantation for BBB repair after TBI.