摘要目的 探讨髓样细胞触发受体1(TREM-1)在肺炎链球菌溶血素(PLY)致大鼠脑损伤中的动态变化及意义.方法 将64只SD大鼠按简单随机法均等分为PLY组和对照组,分别经左侧颈内动脉注射0.1mL PLY和等体积灭菌9g/L盐水;观察注射后4h、6h、12 h和24 h不同时间点脑组织大体和组织学变化,并应用免疫组织化学法检测脑组织中神经细胞损伤标志物胶质纤维酸性蛋白(GFAP)和神经元特异性烯醇化酶(NSE)蛋白表达水平,同时应用酶联免疫吸附法检测TREM-1、肿瘤坏死因子-α(TNF-α)及白细胞介素6(IL-6)表达水平.结果 PLY组脑组织大体和组织学结果提示大鼠脑损伤存在,且脑组织中GFAP和NSE蛋白表达及TNF-α和IL-6表达在4h开始增加,随注射时间点推移,其表达水平动态增加,与相应时间点对照组相比,差异均有统计学意义(P均＜0.05).PLY组脑组织TREM-1蛋白表达在4h明显增加,在6h有所下降,但仍高于对照组,差异均有统计学意义(P均＜0.05),12 h与24 h TREM-1蛋白表达水平明显下降,与对照组相比差异无统计学意义(P均＞0.05).结论 TREM-1蛋白表达在PLY诱发的大鼠脑损伤早期明显上调,可能通过促进炎性因子TNF-α和IL-6的表达而参与脑损伤的病理发展过程.

abstractsObjective To investigate the dynamic level changes and significance of triggering receptor expressed on myeloid cells-1 (TREM-1) in the injury brain tissues of rats caused by pneumolysin (PLY).Methods Sixty-four SD rats were randomly and equally divided into PLY group and control group,0.1 mL PLY and isopyknic normal saline was given through left internal carotid artery respectively.Brain tissue gross and histological changes were observed at different time(4 h,6 h,12 h,24 h),meanwhile the expression levels of neurocyte damage marker glial fibrillary acidic protein (GFAP) and neuron-specific enolase (NSE) protein were detected by immunohistochemistry;and the expression levels of TREM-1,tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were detected respectively by enzyme-linked immunosorbent assay.Results The observation of brain tissue gross and histological changes indicated the existence of brain injury,and the expression levels of GFAP,NSE,TNF-α and IL-6 protein increased from 4 h after PLY were injected and augmented dynamically as time went on,compared with the control group at corresponding time points,the differences were statistically significant (all P ＜ 0.05).The level of TREM-1 in the PLY group reached a peak at the 4 h time point,but decreased somewhat at the 6 h time point,the level of TREM-1 was still higher than that in control group,the differences were statistically significant(all P ＜ 0.05).However,the level of TREM-1 in the PLY group declined obviously at 12 h and 24 h time points,compared with that in control group,there were no significant differences (all P ＞ 0.05).Conclusions The expression levels of TREM-1 up-regulated obviously in the early stage of brain damage induced by PLY,which might be involved in the pathological process of brain damage by promoting the expression of TNF-α and IL-6.