ABSTRACT
Objective To investigate the changes of brain edma and expression of blood high mobil-ity group box 1(HMGB1) and calcium binding protein S100B after traumatic brain injury (TBI) in IL-4 knockout (IL-4 KO) mice,and to explore the effects of IL-4 on traumatic brain injury. Methods Twenty male wild type ( WT) or twenty male IL-4 KO BALB/cJ mice were randomly divided into WT sham TBI group,WT TBI group,IL-4 KO sham TBI group and IL-4 KO TBI group(n=10 in each group).The model of traumatic brain injury was established by the free falling body epidural impact method,then the brain water content was measured. The expression of aquaporin-4 ( APQ4) and HMGB1 in injured brain of each group was detected by Western blot,and the concentration of HMGB1 and S100B in serum was detected by ELISA assay. Results ( 1 ) The brain water content of injured lateral brain of BALB/cJ mice with IL-4 gene knockout was significantly higher than that of wild type mice with brain injury model (WT group: (80.03± 0.35)％;IL-4 KO group:(81.93±0.41)％;P<0.05).(2) The Western blot showed that the expression of AQP4 and HMGB1 in brain tissue of BALB/cJ mice with IL-4 gene knockout was significantly higher than those in wild type mice after traumatic brain injury. ( 3) The results of ELISA showed that the levels of HMGB1 and S100B in the serum of IL-4 knockout BALB/cJ mice were significantly higher than those of wild type mice (HMGB1:WT group:(9.21±0.74)ng/ml;IL-4 gene knock-out group:(13.39±1.33)ng/ml,P<0.05;S100B protein:WT group:(11.11±0.84)pg/ml;IL-4 KO group: (18.11±2.02)pg/ml,P<0.05 ). Conclusion The brain tissue water content and the expression of APQ4 are increased in IL-4 KO TBI mice.The expression of HMGB1 in brain issue and serum and S100B in serum are also up-regulated.