Aβ31-35和ApoE4对体外大鼠基底前脑神经元存活和生长的协同作用

COMBINED EFFECTS OF Aβ31-35 AND ApoE4 ON NEURONAL SURVIVAL AND GROWTH OF THE BASAL FOREBRAIN in vitro IN THE RAT

目的 探讨 β-淀粉样蛋白 (Aβ)和载脂蛋白 (Apo E4)对基底前脑神经元存活和生长的影响 ,研究Alzheimer病 (AD)发病的细胞分子机制。 方法 体外培养基底前脑神经细胞 ,MTT法和免疫细胞化学方法结合体视学分析 ,观察 Aβ31- 35和 Apo E4对基底前脑神经元存活及胞体和突起生长的影响。 结果 (1) MTT法测得的 Aβ- 31- 35 +Apo E4组的 A值 ,与对照组比较明显减小 (P<0 .0 5 ) ,说明神经元的存活力降低 ,存活数量减少 ;(2 )Aβ31- 35 +Apo E4组的神经元胞体最长径和最短径明显低于对照组和 Apo E4组 (P<0 .0 5 ) ;平均突起长度也明显低于对照组、Apo E4组和 Aβ31- 35 (10 μmol/ L)组 (P<0 .0 1) ;(3) Aβ31- 35 (2 0 μm ol/ L)组平均突起长度比对照组、Apo E4组和 Aβ31- 35 (10 μmol/ L)组明显减小 (P<0 .0 1) ;(4) Aβ31- 35 +Apo E4组和 Aβ31- 35 (2 0 μm ol/ L)组的胆碱能神经元最长突起长度、总突起长度及平均突起长度均明显低于对照组 (P<0 .0 1) ;且这两组的 Ch AT阳性神经元的胞体平均灰度也明显低于对照组 (P<0 .0 5 ) ,说明 Ch AT的活性下降。单独 Apo E4对基底前脑神经元的存活和生长均无明显影响。 结论 Aβ31- 35 +Apo E4比单独 Aβ31-

Objective\ In order to explore the combined effects of β\|amyloid protein(Aβ) and apolipoprotein E4(ApoE4) on neurons in the basal forebrain in rat. Methods\ The survival and growth of cultured neurons were measured by MTT assay and immunocytochemistry combined with morphometry. Results\ (1)The average A values of group Aβ31\|35+ApoE4 were lower than that of the control( P <0\^05),which showed that the viability and number of neurons were decreased;(2)The average maximum and minimum diameter of neurons in group Aβ31\|35+ApoE4 and group Aβ31\|35(20μmol/L)were decreased as compared with those of control and group ApoE4( P <0\^05);(3)The average neurite length of group Aβ31\|35+ApoE4 and group Aβ31\|35(20μmol/L) were decreased significantly as compared with that of control, group ApoE4 and group Aβ\|31\|35(10μmol/L)( P <0\^01);(4)The longest process length,the total neurite length,the average neurite and the average gray degrees of ChAT\|positive neurons were decreased significantly in group Aβ\|31\|35+ApoE4 and group Aβ31\|35(20μmol/L) as compared with those of control( P <0\^05),the decrease of the gray degrees of ChAT\|positive neurons indicated that Aβ31\|35+ApoE4 and Aβ31\|35 reduced choline acetyltransferase activity(ChAT).ApoE4 had no significant effect on survival and morphology of the basal forebrain neurons. Conclusion\ The combination of Aβ31\|35 with ApoE4 is more neurotoxic than that of Aβ31\|35 alone,which implies that ApoE4 may play an important role in enhancing the neurotoxicity of Aβ31\|35.\;