Correlations between degrees of traumatic brain injury and expressions of monocyte chemoattractant protein-1 and vascular endothelial growth factor in the serum, and CD34+ cells in the damage zone of rats

Abstract

Objective To explore the correlations between degrees of traumatic brain injury and expressions of serum monocyte chemoattractant protein-1 (MCP-1),and serum vascular endothelial growth factor (VEGF),and number of CD34+ cells of the damage zone in rats.Methods Eighty clean adult SD rats were randomly divided into control group,sham-operated group,slight injury group and severe injury group (n=20).Feeney protocol was employed to establish the rat brain traumatic models.Modified neurological severity scale (mNSS) was used to evaluate the neurological function 3 and 7 d after the injury; the peripheral blood was collected at 1,3,6 and 9 h,and 1,3,5 and 7 d after the injury,and the expressions of serum MCP-1 and VEGF were detected by enzyme-linked immuno sorbent assay (ELISA).After the rats being affused with paraformaldehyde,the brain tissues were collected at 6 h,1,3 and 7 d after the injury; the CD34+ cells in the injury areas were detected by immunohistochemistry (SP staining).Results As compared with the rats in the slight injury group,those in the severe injury group had significantly higher mNSS scores (P＜0.05).Immunohistochemistry showed that the number of CD34+ cells of the damage zone was small in control group and sham-operated group; the CD34+ cells appeared in the injury area of slight injury group and severe injury group,and the amount ofCD34+ cells in severe injury group was smaller than that in the slight injury group.ELISA showed the expressions of MCP-1 and VEGF in peripheral blood in the control group and sham-operated group were significantly lower than those in the slight injury group and severe injury group at all observation time points (P＜0.05);the expression of MCP-1 in the severe injury group was significantly higher than that in the slight injury group (P＜0.05); the expression of VEGF in the slight injury group was statistically higher than that in the severe injury group (P＜0.05).Conclusion The expression of serum MCP-1 is positively correlated to the severity of brain trauma injury; the expression of serum VEGF and the number ofCD34+ cells in the area of brain injury are negatively correlated to the severity of brain trauma injury; all of these indices could be used to evaluate the severity of traumatic brain injury in rats. Key words: Traumatic brain injury; Monocyte chemoattractant protein-1; Vascular endothelial growth factor; CD34+ cell; Classification