【摘要】 目的探讨粒细胞集落刺激因子(G-CSF)对阿尔茨海默病(AD)大鼠认知障碍的改善作用及其对脑内炎症反应的影响。方法 45只雄性SD大鼠,随机分为3组,包括假手术组、模型组、G-CSF组,每组15只。采用β-淀粉样蛋白1-42(Aβ1-42)复制AD大鼠模型,并给予G-CSF治疗。观察并比较大鼠的学习记忆功能及脑组织病理学变化。采用Western blotting检测核因子κB p65(NF-κB p65)、磷酸化p-38丝裂原活化蛋白激酶(p-p38MAPK)、诱导型一氧化氮合酶(i NOS)、环氧化酶-2(COX-2)、肿瘤坏死因子α(TNF-α)和白细胞介素-1β(IL-1β)蛋白的表达,采用Real-time PCR检测i NOS、COX-2、TNF-α和IL-1βmRNA水平。结果模型组大鼠神经细胞数量明显减少,细胞核固缩明显,核仁不清。G-CSF组大鼠脑组织神经细胞核固缩现象均有显著改善。假手术组、模型组、G-CSF组逃避潜伏期分别为(35.68±6.73) s、(57.92±7.35) s及(40.27±8.91) s;目标象限游泳时间分别为54.72%±4.22%、36.73%±3.21%及44.68%±4.01%;穿过平台次数分别为(8.7±2.1)次、(3.9±1.6)次及(6.5±1.7)次;与模型组相比,假手术组、G-CSF组的逃避潜伏期均显著缩短,目标象限游泳时间显著增加,穿过平台次数显著增加,差异均有统计学意义(P<0.05)。假手术组、模型组、G-CSF组NF-κB p65蛋白表达水平为0.144±0.033、0.502±0.035及0.473±0.061; pp38 MAPK蛋白水平为0.194±0.021、0.511±0.039及0.266±0.048,与模型组相比,假手术组、G-CSF组NF-κB p65、pp38MAPK蛋白水平均显著降低,差异均有统计学意义(P<0.05)。与模型组比较,假手术组、G-CSF组i NOS、COX-2、TNF-α和IL-1β的蛋白和mRNA水平显著降低(P<0.05)。结论 G-CSF具有良好的抑制AD模型大鼠脑神经细胞凋亡,改善大鼠学习记忆功能障碍的作用,其作用可能通过抑制p38MAPK和NF-κB p65的信号通路的过度激活,下调i NOS、COX-2、TNF-α和IL-1β等炎性因子的表达,抑制脑内神经炎症状态而实现。更多还原

【Abstract】 Objective To investigate the effect of granulocyte colony-stimulating factor(G-CSF) on cognitive impairment in Alzheimer’s disease(AD) in rats and its effect on brain inflammatory response.Methods Forty-five male Sprague-Dawley rats were randomly divided into 3 groups:sham operation group,model group,and G-CSF group.Rat models were induced by intracerebro ventricular injection of amyloid beta-peptides 1-42(Aβ1-42),and then G-CSF were given to G-CSF group.The learning and memory function and brain histopathological changes were observed and compared.The expression of nuclear factor κB p65(NF-κB p65),phosphorylated p38 mitogen activated protein kinase(pp38 MAPK),inducible nitric oxide synthase(i NOS),cyclooxygenase-2(COX-2),tumor necrosis factor α(TNF-α) andinterleukin-1β(IL-1β) were detected by Western blotting.The levels of i NOS,COX-2,TNF-α and IL-1β mRNA were detected by Real-time PCR.Results The number of neurons in the model group decreased significantly,the nuclear condensation was obvious and the nucleolus was unclear.Neuronal nuclear condensation was significantly improved in GCSF group.The escape latency of the sham group,model group and G-CSF group were(35.68±6.73) s,(57.92±7.35)s and(40.27±8.91) s.The swimming time of the target quadrant was 54.72% ± 4.22%,36.73% ± 3.2% and 44.68% ±4.01%.The times of crossing the platform were 8.7±2.1,3.9±1.6 and 6.5±1.7.Compared with the model group and the control group,the escape latency of G-CSF group were significantly shorter,target quadrant swimming time increased significantly,through the platform number increased significantly,the difference had statistical significance(P<0.05).In the sham group,model group and G-CSF group,the protein levels of NF-κB p65 were 0.144±0.033,0.502±0.035 and0.473±0.061,the protein levels of p-p38 MAPK were 0.194±0.021,0.511±0.039 and 0.266±0.048.Compared with the model group,the levels of NF-κB p65 and p-p38 MAPK protein in the sham group and G-CSF group decreased significantly,and the difference was statistically significant(P < 0.05).Compared with the model group,the protein and mRNA levels of i NOS,COX-2,TNF-α and IL-1β in the sham group and G-CSF group were significantly lower than those in the model group(P < 0.05).Conclusion G-CSF can improve the learning and memory dysfunction of rats with Alzheimer’s disease probably through inhibiting the activation of p38 MAPK and NF-κB p65 signaling pathways and downregulating i NOS,COX-2,TNF-α and IL-1β expressions to inhibit the neuroinflammatory state of the brain.更多还原