人羊膜上皮细胞移植改善AD样病变模型大鼠学习记忆能力

Transplantation of human amnion epithelial cells improves learning and memory function in Alzheimer's disease-like pathology rat model

目的:观察人羊膜上皮细胞(h AECs)对阿尔茨海默病(AD)样病变大鼠模型的治疗效应。方法:采用胰蛋白酶消化法分离h AECs,流式细胞术分析表型。48只雄性SD大鼠随机分为假手术组、模型组、培养基组和h AECs移植组,每组12只。采用双侧脑室注入脂多糖(LPS)复制AD样病变大鼠模型。AD样病变大鼠海马区移植5×105个h AECs。细胞移植后2周,Morris水迷宫试验观察行为学变化,HE和硫磺素S染色观察海马病理变化,免疫组化染色检测β-淀粉样蛋白42(Aβ42)、Tau蛋白和乙酰胆碱(ACh)的变化,流式细胞术检测外周血T淋巴细胞亚群的变化,流式微球阵列捕获技术(cytometric bead array,CBA)检测血清细胞因子含量,免疫荧光染色检测海马区人细胞核抗原阳性细胞及其神经元特异性核蛋白(Neu N)的表达。结果:与模型组和培养基组比较,h AECs移植组大鼠逃避潜伏期明显缩短(P<0.01),跨域平台次数明显增加(P<0.05);海马神经元病损减轻,Aβ沉积减轻(P<0.05),磷酸化Tau蛋白水平下降(P<0.05),ACh增加(P<0.05);外周血Th1和Th17细胞百分比下降(P<0.05),而Th2和Treg细胞升高(P<0.05);IL-2和IFN-γ水平下调(P<0.05),而IL-4上调(P<0.05);移植区可见h AECs,并表达Neu N。结论:h AECs可明显改善AD样病变模型大鼠空间辨别性学习记忆能力,减轻海马病理损伤,其免疫调节效应可能发挥重要作用。

AIM： To observe the treatment effect and its immune regulation of human amnion epithelial cells （hAECs） on Alzheimer＇ s disease （AD）-like pathology rat model. METHODS： The hAECs were isolated from amnion with trypsin digestion, and the phenotype of hAECs was analyzed by flow cytometry. SD rats （ n = 48 ） were randomly divid- ed into sham control group, model group, medium group and hAECs group. AD-like pathology rat model was induced by bilateral intraventricular injection of lipopolysaccharide （LPS）. hAECs （5 × 10^5） were injected into the hippocampus of the AD-like pathology rats. At 2 weeks after transplantation, the animals were tested by Morris water maze to observe the function of learning and memory. The pathological change of the brain was observed by HE staining. The expression of am- yloid p-protein 42 （Aβ42） and Tau protein and the level of acetylcholine （ACh） in the injury brain were determined by immunohistochemistry. The survival and differentiation of hAECs in the hippocampus were measured by immunofluorescent technique. The percentages of lymphocyte subsets in the peripheral blood mononuclear cells were analyzed by flow cytome- try. The contents of serum cytokines were detected by cytometric bead array. RESULTS ： Compared with model group and medium group, hAECs group showed shortened escape latency （P 〈 0. 01 ）, increased frequency of going through the plat- form （P 〈 0. 05） , reduced loss of hippocampal neurons, decreased expression of Tau protein and Aβ42 in the hippocampus （ P 〈 0. 05 ）, increased ACh level in the hippocampus （ P 〈 0. 05 ）, decreased percentages of Thl and Th17 subsets, in-creased percentages of Th2 and Treg cells （ P 〈 0. 05 ） , decreased concentrations of IFN-γ and IL-2 in the serum, and in- creased concentration of IL-4 （P 〈 0. 05 ）. CONCLUSION： hAECs improve the cognitive learning and memory function and alleviate pathologic damage of hippocampus through immune regulation in AD-like pathology rats.