星形胶质细胞、胶质纤维酸性蛋白及内皮抑素水平与重症创伤性脑损伤结局的关系探讨

Relationship Between Astrocye,Glial Fibrillary Acidic Protein and Endostatin Levels and Outcome of Severe Traumatic Brain Injury

目的:探讨星形胶质细胞(AC)、胶质纤维酸性蛋白(GFAP)及内皮抑素(ES)水平与重症创伤性脑损伤(TBI)结局的关系。方法:选取105只健康雄性Wistar大鼠,采用随机数字表法分为健康组、TBI组、假手术组,各35只。TBI组采用改进的Feney’s自由落体撞击法制作脑外伤模型,保证撞击后大鼠的神经功能损伤评分相同;假手术组仅切开头皮和颅骨开窗;健康组不做处理。各组分别在伤后6 h、12 h、24 h、3 d、7 d、14 d、21 d随机取出5只大鼠,应用改良神经功能损伤评分系统(mNSS)进行神经功能评分。常规苏木精-伊红染色法(HE)染色,采用免疫组织化学染色法作GFAP、ES染色,分别以AC、小胶质细胞的胞质内出现黄色或棕褐色颗粒为阳性细胞。结果:健康组及假手术组GFAP免疫组织化学染色AC胞质呈棕褐色,形如蜘蛛,周围有放射状突起;ES免疫组织化学染色无明显阳性细胞。TBI组HE染色,可见脑组织水肿,部分神经元及神经胶质细胞变性坏死,损伤3 d内,挫伤灶内细胞数目减少,随时间延长可见胶质细胞逐渐增生。TBI组GFAP阳性细胞平均面积随时间延长而逐渐增加,在7 d及14 d达到高峰,且TBI组阳性细胞平均面积大于健康组,差异有统计学意义(P<0.05)。大鼠GFAP与重症TBI结局有关,其GFAP阳性细胞平均面积水平越高,mNSS评分越高。与健康组比较,TBI组6~24 h未检测到ES明显表达变化,差异无统计学意义(P>0.05),伤后3~21 d ES含量逐渐增加,差异有统计学意义(P<0.05)。结论:可通过AC、GFAP及ES水平判断重症TBI结局。

Objective:To investigate the relationship between astrocyte(AS),glial fibrillary acidic protein(GFAP)and endostatin(ES)levels and the outcome of severe traumatic brain injury(TBI).Methods:A total of 105 healthy male Wista rats were selected and divided into healthy group,TBI group and sham operation group according to random number table method,with 35 rats in each group.In TBI group,the modified Feney's free-fall impact method was used to establish the brain injury model and ensure that the neurological injury score of rats after impact was the same.The sham operation group was treated with scalp and skull incision.The healthy group was not treated.Five rats were randomly selected from each group at 6 h,12 h,24 h,3 d,7 d,14 d and 21 d post-injury,respectively.The modified neurologic severity score(mNSS)was used to score the neurological function.Conventional hematoxylin-eosin staining(HE)was performed.Immunohistochemical staining was used for GFAP and ES staining.The yellow or brown particles in the cytoplasm of AC and microglia were considered as positive cells.Results:GFAP immunohistochemical staining showed that AC cytoplasm in healthy group and sham operation group was brown,like spider,with radial protrusions around it.ES immunohistochemical staining showed no obvious positive cells.In the TBI group,HE staining showed edema of brain tissue,degeneration and necrosis of some neurons and glial cells.Within 3 d of injury,the number of cells in the contusion focus was reduced,and glial cells were gradually proliferated with the prolonging time.The average area of GFAP positive cells in TBI group increased gradually with the prolonging time,and reached the peak on 7 d and 14 d.The average area of positive cells in TBI group was higher than that in healthy group,with statistically significant difference(P<0.05).GFAP in rats was related to the outcome of severe TBI.The higher average area of GFAP positive cells indicated the higher mNSS scores.Compared with the healthy group,the expression of ES in TBI group was not significantly changed at 6-24 h,without statistically significant difference(P>0.05),and the content of ES gradually increased at 3-21 d after injury,with statistically significant difference(P<0.05).Conclusion:The levels of AC,GFAP and ET can be used to judge the outcome of severe TBI.