摘要目的 旨在从MLL3(mixed-lineage leukemia 3,MLL3)基因入手,尝试探讨Alzheimer病(Alzheimer's disease,AD)与该基因表达量的相关关系.方法 在45例AD患者、25例血管性痴呆(vascular dementia,VD)患者和60名年龄性别相匹配的对照组中进行,在新鲜外周血样本中抽提总RNA,反转录成cDNA,基因表达量的检测在ABI Prism7900HT型序列监测系统上进行,采用SYBRGreenⅠ的方法对患者及对照组样本的mRNA进行绝对定量,采集的荧光数据经SDS2.1软件自动处理,每个样本作3次乎行检测,取平均值作为该样本的最终定量.对组间基因表达量的差异进行独立样本的t检验.结果 检测得到MLL3基因在对照组中的表达量为(0.59±0.18)amol/μg cDNA,在AD患者组中的表达量为(2.52 ±0.59)amol/μg cDNA,在VD患者组中的表达量为(0.33 ±0.05)amol/μg cDNA.经显著性检验,AD患者组与正常对照组相比较,t=3.140,df 52.67,P=0.003,差异有统计学意义,95%CI:0.174～0.791;VD患者组与正常对照组相比较,t=-0.959,df 82,P=0.341,差异无统计学意义.调用本实验室已有的ApoE基因分型资料,分析ApoE基因型与MLL3基因表达之间的相互关系,经差异显著性检验,不携带ε4等位基因的AD患者组与不携带ε4等位基因的正常对照组相比较t=3.255,df30.40,P=0.003,差异有统计学意义,95%CI:0.177～0.772.结论 MLL3基因表达的增强可能特异性地与AD的发生相关联,并且这种关联性尤以不携带ApoE基因ε4等位基因的AD显著.

abstractsObjective To search the association between the level of expressed MLL3(mixed-lineage leukemia 3,MLL3)gene and Alzheimer's disease(AD).Methods 45 patients with AD,25 patients with VD(vascular dementia,VD)and 60 healthy controls were involved in this research work.Total cellular RNA was extracted from peripheral blood,then reverse transcripted into cDNA.Real-time quantitative PCR using SYBR Green Ⅰ dye was performed with ABI PRISM 7900 HT(Applied Biosystems).Experiments were typically performed three times with triplicate determination and each gene expression level was determined by the average of three independent experiments.T test was used to analyze the sample quantities.Results The MLL3 gene expression levels were(0.59±0.18)amol/μg cDNA in healthy controls,(2.52 ±0.59)amol/μg cDNA in AD patients and(0.33±0.05)amoL/μg cDNA in VD patients.Compared with healthy COntrols,AD patients had up-regulated expression level(t=3.140,df 52.67,P=0.003,95%CI:0.174～0.791),and the expression level in VD patients and that of healthy controls had no statistical differences(t=-0.959,df 82,P =0.341).Taking the ApoE genotype into account,MLL3 gene expression levels in AD patients without ε4 allele had up-regulated than that of healthy controls without ε4 allele(t=3.255,df 30.40,P=0.003,95%CI:0.177～0.772).Conclusion It seems that the enhanced MLL3 gene expression associates with AD particularly with the AD patients without ε4 allele.