目的 研究闭合性颅脑损伤大鼠血清和海马SAX2蛋白质表达谱,探寻脑损伤生物标志蛋白。方法 选72只雄性SD大鼠随机分为手术对照组及损伤后4、8、12、24、48 h组,复制Marmarou落体打击大鼠脑损伤模型,分别进行常规HE染色、尼氏染色;并用强阴离子交换芯片(SAX2)质谱技术分析大鼠闭合性脑损伤后不同时间血清和海马中蛋白质表达谱的改变。结果 (1)SAX2芯片共获得530个血清蛋白质峰,147个海马蛋白质峰,6个组中,SAX2芯片在血清和海马中都能捕获的蛋白质数是14个。(2)血清中检测到的差异蛋白质,损伤后共有45个蛋白质峰的相对强度与手术对照组比较差异有统计学意义(P＜0.05);另有97个蛋白质峰在对照组中未检测到。(3)海马中检测到的差异蛋白质,损伤后共有18个蛋白质峰的相对强度与手术对照组比较差异有统计学意义(P＜0.05);另有40个蛋白质峰在对照组中未检测到。(4)在SAX2芯片上,血清和海马中均能检测到3656Da这一蛋白质,该蛋白质在血清中于损伤后4 h可以检测到,在海马中于损伤后12 h可检测到。结论 脑损伤可引起血清和海马SAX2蛋白质表达谱变化;血清和海马SAX2蛋白质表达谱存在差异,提示血清中出现的部分蛋白质可能为脑损伤诱导的血细胞基因表达产物;在血清和海马中检测到的差异蛋白质以及损伤后新出现的蛋白质峰,可能是脑损伤生物标志蛋白。

Objective To study the alteration of SAX2 protein expression pattern in rat serum and hippocampus after closed head injury and to find biomarkers of brain injury. Methods Male Sprague-Dawley rats were randomly divided into sham operation group and injury groups which were subjected to Marmarou’s brain injury and then subdivided into 4 h、8 h、12 h、24 h and 48 h groups according to the time elapsed after injury. The pathological study included H&E staining and toluidine blue staining. The change of protein expression pattern in serum and hippocampus were monitored with strong anion exchange chips (SAX2). Results (1)A total of 530 protein peaks were detected on SAX2 chips in serum,and a total of 147 protein peaks in hippocampus. (2) Among the total of protein peaks detected, the relative intensity of 45 protein peaks was shown to be differentially altered on SAX2 chips in serum of injury groups, compared with sham operation group(P＜0.05). There were 97 protein peaks in serum of injury groups, which could not be detected in sham operation group with SAX2 chips. (3) The relative intensity of 18 protein peaks was shown to be differentially altered on SAX2 chips in hippocampus of injury groups compared with sham operation group(P＜0.05). There were 40 protein peaks in hippocampus of injury groups which could not be detected in sham operation group with SAX2 chips. (4) On SAX2 chips, only one protein(3656Da) peak was detected not only in serum but also in hippocampus. Conclusions The alteration of SAX2 protein expression patterns in serum and hippocampus can be induced after brain injury. The SAX2 protein expression patterns of serum and hippocampus after brain injury are different, which suggests that part of protein in serum can be a production of blood cells gene expression induced by brain injury. The distinct proteins detected in serum and hippocampus includ the proteins which are significant, compared with sham operation group and those which are not detected in sham operation group. They can be biomarkers of brain injury.