目的探讨协同信号分子B7-H3对肺炎链球菌性脑膜炎小鼠模型中炎性趋化因子巨噬细胞炎性蛋白2(MIP-2)mRNA表达的影响。方法1.5~2.0个月健康雄性BALB/C小鼠48只,随机分为4组:9g/L盐水组(Ns组)、B7-H3蛋白组(B7-H3组)、肺炎链球菌组(SP组)、肺炎链球菌+B7-H3蛋白组(联合组),每组12只;经小鼠侧脑室穿刺分别注入9g/L盐水、B7-H3蛋白、肺炎链球菌3型、肺炎链球菌3型+B7-H3蛋白建立动物模型。注射后6、24h依据loeffler5分制评分方法对各组小鼠进行神经行为评分,然后麻醉处死小鼠,取脑组织,用Real—timePCR方法检测小鼠脑组织内MIP-2mRNA的相对表达量。应用SPSS18.0软件进行统计学分析。结果侧脑室穿刺注射6、24h后各组小鼠神经行为学评分结果:B7-H3组神经行为评分与NS组比较差异无统计学意义(P〉0.05);SP组评分较NS组明显降低,差异具有统计学意义(P〈0.05);联合组较sP组评分更明显降低,差异具有统计学意义(P〈0.05)。Real—timePCR方法检测结果:sP组在注射6h后MIP-2mRNA的相对表达量较NS组升高[(1.210±0.932)比(1.000±0.008)],但差异无统计学意义(P〉0.05);在注射24h后sP组MIP-2mRNA的相对表达明显高于Ns组[(12.880±7.792)比(1.000±0.091)],差异具有统计学意义(P〈0.05);联合组与sP组比较:6hMIP-2相对表达量增高[(1.240±0.804)比(1.210±0.932)],但无统计学差异(P〉0.05),24h相对表达量明显升高[(38.760±6.061)比(12.880±7.792)],差异具有统计学意义(P〈0.05)。结论在肺炎链球菌性脑膜炎模型中,协同信号分子B7-H3使炎性趋化因子MIP-2mRNA的表达上调,促进病情进展。
Objective To investigate the effect of B7-H3 protein, a collaborative signal molecule,on macro- phage-inflammatory protein 2 (MIP-2) mRNA level in Streptococcus pneumococcal meningitis mouse models. Methods Forty-eight healthy male BALB/C mice at the age of 1.5 -2.0 months were randomly divided into 4 groups:9 g/L saline group ( NS group) , B7-H3 protein group ( BT-H3 group ) , Streptococcus pneumoniae group ( SP group) , and Strep- tococcus pneumoniae plus B7-H3 protein group( combination group) , 12 mice in each group. Mouse models were estab- lished by intracerebral ventricular injection with 9 g/L saline, B7-H3 protein, Streptococcus pneumoniae type 3 or Strep- tococcus pneumoniae type 3 plus B7-H3 protein. Neurobehavior of different groups was evaluated according to loeffler nile after injection for 6 h and 24 h, then the mice were sacrificed and MIP-2 mRNA levels were tested by Real - time PCR. The results were analyzed by SPSS 18.0 software. Results Neurobehavior scoring results showed that there were no significant differences between B7-H3 group and NS group ( P 〉 0.05 ) after infection for 6 h and 24 h, while the score of SP group was decreased compared with that of NS group (P 〈 0.05 ) , and the score of combination group was significantly decreased compared with that of SP group ( P 〈 0.05 ). Real - time PCR results showed that, compared with the NS group, the relative MIP-2 mRNA level in SP group increased after injection for 6 hours (1. 210±0. 932 vs 1. 000±0. 008 ) , but the difference was not significant ( P 〉 0.05 ), while at 24 h post infection, the relative MIP-2 mRNA expressions in SP group were significantly increased compared with that of NS group( 12.880±7. 792 vs 1. 000±0. 091 ) ,the difference was significant (P 〈 0.05 ). At 6 h post infection, SP + B7-H3 treatment enhanced the MIP-2 mRNA production compared to SP infection alone, but the difference was not significant [ ( 1. 240±0. 804 ) vs ( 1. 210±0.932 ) ] ?