β-淀粉样蛋白诱导骨髓间充质干细胞向神经元样细胞分化过程中Tau蛋白的过度磷酸化  

Beta-amyloid 25-35 causes Tau protein hyperphosphorylation of bone marrow mesenchymal stem cells differentiating into neuron-like cells

作　　者：李俊[1] 赵天春[1] 段萍[1] 韩雪飞[1] 梁晨[1] 邢莹[2] 

机构地区：[1]郑州大学基础医学院干细胞中心,河南省郑州市450001 [2]新乡医学院,河南省新乡市453003

出　　处：《中国组织工程研究与临床康复》2011年第40期7425-7428,共4页Journal of Clinical Rehabilitative Tissue Engineering Research

摘　　要：背景：大多数学者认为β-淀粉样蛋白是阿尔茨海默病发病的始动因素,而Tau蛋白过度磷酸化可能是阿尔茨海默病最重要的分子病理变化之一。目的：观察β-淀粉样蛋白25~35对大鼠骨髓间充质干细胞分化的神经元样细胞Tau蛋白磷酸化的影响。方法：体外分离纯化大鼠骨髓间充质干细胞,将第4代骨髓间充质干细胞分为两组：实验组中加入预诱导培养基和20μmol/Lβ-淀粉样蛋白25~35,24h后用含2%二甲基亚砜和200μmol/L丁羟茴醚的DMEM诱导其向神经细胞分化,5h后收取细胞。对照组诱导方法同实验组,但在诱导过程中未加入β-淀粉样蛋白25~35。结果与结论：光镜下可见纺锤状的骨髓间充质干细胞诱导后出现长突起,呈现神经细胞样形态,但实验组突起数量和长度均少于对照组;免疫细胞化学法检测两组诱导后的神经元样细胞为神经元特异性烯醇化酶阳性;免疫蛋白印记法证明实验组的GSK-3β、Tau[pSer262]和Tau[pSer396]表达均显著高于对照组。结果提示β-淀粉样蛋白25~35能够通过GSK-3β途径诱导骨髓间充质干细胞分化的神经元样细胞Tau蛋白过度磷酸化。BACKGROUND： Many scholars believe that β-amyloid protein is the initial factor for the occurrence of Alzheimer’s disease, and the hyperphosphorylation of Tau protein may be one of the most important molecular pathological changes in Alzheimer’s disease. OBJECTIVE： To study the effect of β-amyloid 25-35 （Aβ25-35） on Tau protein phosphorylation of rat bone marrow mesenchymal stem cells （BMSCs） differentiating into neuron-like cells. METHODS： BMSCs were isolated and purified from SD rats, and the fourth passage BMSCs were divided into two groups： Aβ25-35 experiment group was added pre-induction medium （containing 10 μg/L bFGF, 10% FBS in DMEM） and 20 μmol/L Aβ25-35, 24 hours later, the cells were induced into neurons-like cells by DMEM with 2% DMSO and 200 μmol/L BHA, and harvested 5 hours later; control group was treated with the same induction method but with no Aβ25-35. Morphological changes were observed by light microscope, neuron-specific enolase （NSE） detected by immunocytochemistry; GSK-3β, Tau [pSer262] and Tau [pSer396] are tested by Western blot. RESULTS AND CONCLUSION： With the observation of light microscope, spindle shaped BMSCs after induction showed up neuron-like cells shape with long projections, which were different from Aβ25-35 experiment group with the length and quantity of the projections shorter and less; both two groups showed Tau＋ by immunocytochemistry; Western blotting showed that GSK-3β, Tau [pSer262] and Tau [pSer396] of Aβ25-35 treatment group were significantly higher than those of the control group. Aβ25-35 can induce BMSCs differentiating into neuron-like cells leading to the hyperphosphorylation of Tau protein through GSK-3.

关 键 词：TAU蛋白 磷酸化 β-淀粉样蛋白 骨髓间充质干细胞 大鼠 

分 类 号：R394.2[医药卫生—医学遗传学]