目的 观察神经营养因子3(NT3)-壳聚糖载体对大鼠运动皮层损伤后的前肢行为学功能恢复的效果,并检测其对损伤区及侧脑室下区神经干细胞(NSCs)的增殖和分化的影响。方法 65只Wistar大鼠分为正常对照组(n=7)、单纯损伤组(n=29)和NT3-壳聚糖组(n=29)。制作大鼠运动皮层吸除损伤性脑损伤模型。NT3-壳聚糖组于手术后立即植入NT3-壳聚糖载体,单纯损伤组不给予任何治疗措施。分别于术后3 d、7 d、14 d、1个月、2个月和3个月,应用食物球抓取实验观察大鼠前肢功能恢复情况,应用HE染色观察损伤区的空腔体积,应用免疫荧光染色评价NSCs的增殖和分化。结果 NT3-壳聚糖组右侧前肢抓取成功率高于单纯损伤组右侧(F>6.00, P≤0.05)。NT3-壳聚糖组空腔体积均显著小于单纯损伤组(F>629.5, P<0.001)。在NSCs分化实验中,NT3-壳聚糖组各时间点损伤区BrdU细胞数均显著高于单纯损伤组(F>171.43, P<0.001)。在NSCs增殖实验中,NT3-壳聚糖组BrdU阳性细胞数显著高于正常对照组和单纯损伤组(F>155.06, P<0.001),术后7 d损伤同侧Dcx阳性细胞数显著高于单纯损伤组(F=62.367, P<0.001),BrdU/Dcx双阳性细胞数显著高于正常对照组(F=33.527, P<0.001)。结论 NT3-壳聚糖载体可增加脑损伤所致的侧脑室下区NSCs的增殖,促进损伤区新生神经元的发生以及大鼠前肢运动功能恢复。
Objective To observe the effects of neurotrophin 3 (NT3)-chitosan on motor function, and proliferation and differentiation of the neural stem cells (NSCs) in the injury area and subventricular zone (SVZ) in rats with motor cortex injury. Methods Sixty-five Wistar rats were divided into control group (n=7), injury group (n=29) and NT3-chitosan group (n=29). The motor cortex was aspirated and removed as cerebral injury model. NT3-chitosan was immediately implanted into the injured area after operation, and the control group received no intervention. Pellet reaching test was performed to detect the recovery of the forelimb function, HE staining was used to observe the lesion cavity size, and immunofluorescence staining was used to observe the proliferation and differentiation of NSCs 3 days, 7 days, 14 days, 1 month, 2 months and 3 months after operation. Results The grasp success rate was higher (F>6.00, P≤0.05), and the lesion cavity size was significantly smaller (F>629.5, P<0.001) in the NT3-chitosan group than in the injury group. In the NSCs differentiation experiment, the number of BrdU cells at all the time points was significantly higher in the NT3-chitosan group than in the injury group (F>171.43, P<0.001). In the NSCs proliferation experiment, the number of BrdU positive cells was still significantly higher in the NT3-chitosan group than in the control group and in the injury group (F>155.06, P<0.001), the number of Dcx positive cells was significantly higher in the NT3-chitosan group than in the injury group (F=62.367, P<0.001), and the number of BrdU/Dcx positive cells was significantly higher in the NT3-chitosan group than in the control group (F=33.527, P<0.001). Conclusion NT3-chitosan could activate NSCs in the SVZ, and promote endogenous neurogenesis and forelimb function recovery in rats after motor cortex injury.
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