经鼻给予碱性成纤维细胞生长因子治疗大鼠脑梗死的研究

Intranasal administration of basic fibroblast growth factor for a rat model of cerebral infarction:an experimental study

目的探讨经鼻给予碱性成纤维细胞生长因子（bFGF）对脑梗死大鼠内源性神经干细胞再生的影响。方法取成年雄性SD大鼠36只,随机分为假手术组（n=12）、对照组（n=12）、bFGF组（n=12）。对照组和bFGF组大鼠采用大脑中动脉线栓法建立局灶性脑缺血-再灌注模型,术后第1-6天,分别经鼻给予等渗盐水（30μl）或bFGF（每天30μg,30μl）。在术前及术后第1、7、14、21、28天对脑梗死后大鼠神经功能恢复的程度进行改良神经功能缺损评分（mNSS）。采用苏木素染色法测定脑梗死大鼠在术后第7、28天的脑梗死体积;采用免疫组化法测定术后第7和28天缺血侧室管膜下区（SVZ）及纹状体5-溴脱氧尿核苷（BrdU）阳性细胞数;激光共聚焦观察第7天时BrdU与doublecortin（DCX）的免疫荧光双标染色情况。结果与对照组相比,bFGF组从术后第7天开始,大鼠神经功能就显著恢复,术后第1、7、14、21、28天,对照组mNSS评分分别为8.7±1.0、7.2±0.8、6.7±1.0、6.2±0.8、5.8±1.2;bFGF组分别为8.8±0.8、6.2±0.8、5.3±0.8、5.0±0.6、4.3±0.8。两组间各时间点相比,P值分别为0.756、0.044、0.033、0.016、0.028,显示了其明显的正性干预作用。而对照组与bFGF组大鼠的脑梗死体积差异无显著性。假手术组大鼠无梗死灶。BrdU免疫组化显示,术后第7和28天,经鼻给予bFGF组大鼠在SVZ和纹状体区域BrdU阳性细胞数与对照组相比均显著增高,第7天时,SVZ的大部分BrdU阳性细胞共标不成熟神经元标记物——DCX。假手术组大鼠无明显神经功能缺损症状。结论经鼻给予bFGF,能够诱导脑梗死大鼠内源性神经干细胞的增殖和存活,促进神经功能的恢复。经鼻腔给予bFGF是一种有前途的治疗脑梗死的方法。

Objective To investigate the effect of intranasal administration of basic fibroblast growth factor （bFGF） on regeneration of endogenous neural stem cells in rats with cerebral infarction.Methods Thirty-six adult male rats were randomly assigned to sham-operation, control and bFGF groups（n=12 in each group）. A focal cerebral ischemia/reperfusion model was induced by middle cerebral artery intraluminal suture occlusion （MCAO） method in the control and bFGF groups. Normal saline or bFGF （30 μg per day） was administered intranasally to the control or bFGF group rats from 1 to 6 days after the procedure. After cerebral infarction was established, the degree of neurological functional recovery of rats was assessed by mNSS scores 1, 7, 14, 21 and 28 days before and after the procedures. The volume of cerebral infarction was detected by hematoxylin staining method in rats with cerebral infarction 7 and 28 days after the procedure, the numbers of positive cells in the ipsilateral subventricular zone （SVZ） and bromodeoxyuridine （BrdU） in striatum were assessed by immunohistochemical method, A confocal laser-scanning microscope was used to observe the double-labeled cells of BrdU and doublecortin （DCX） at day 7.Results As compared with the control group, the rats in bFGF group had significant recovery of neurological function from the 7th days after the procedures （1, 7, 14, 21 and 28 days after the procedures, the scores in the control group were 8.7±1.0, 7.2±0.8, 6.7±1.0, 6.2±0.8 and 5.8±1.2, respectively, the scores in the bFGF group were 8.8±0.8, 6.2±0.8, 5.3±0.8, 5.0±0.6 and 4.3±0.8, respectively, the P values between the two groups at each time point were 0.756, 0.044, 0.033, 0.016 and 0.028, respectively）, which showed its positive intervention effects markedly. However, there were no significant differences between the control and bFGF groups in the volume of cerebral infarction. The immunohistochemistry of BrdU showed that the numbers of bFGF positive cells in SVZ and striatum at 7 and 28 days after the procedures in the bFGF group were significantly higher than those in the control group. The most BrdU positive cells of SVZ at day 7 co-labeled the immature neuronal marker-DCX.Conclusions Intranasal administration of bFGF may induce the proliferation and survival of endogenous neural stem cells and promote recovery of neurological function, Intranasal adminisit is a promising strategy for the treatment of cerebral infarction.