甲基丙二酸血症患儿血浆microRNA表达变化的初步研究

A preliminary study of plasma microRNA levels in children with methylmalonic acidemia

目的筛选甲基丙二酸血症(MMA)患儿血浆中表达差异的microRNA(miRNA),并检测miR-9-1在MMA患儿血浆中的表达变化,初步探讨miR-9-1作为MMA潜在的生物标记物的意义。方法收集17例MMA患儿血浆样本,其中MMA合并高同型半胱氨酸血症12例(MMA+HHcy组)、不伴高同型半胱氨酸血症的MMA 5例(MMA组);另收集10例非MMA的高同型半胱氨酸血症(HHcy组)和10例健康对照者的血浆样本。采用miRNA微阵列基因芯片法筛选具表达差异的miRNA,选择具有表达差异的miR-9-1行RTPCR法检测血浆中miR-9-1的表达。选择经维生素B12治疗的MMA患儿检测治疗后血浆miR-9-1表达的变化。结果 miRNA微阵列基因芯片共筛选出26个具有表达差异的miRNA,其中下调2倍以上的miRNA 16个(包括miR-9-1),上调2倍以上的10个。MMA+HHcy组、MMA组及HHcy组miR-9-1的表达量较健康对照组均显著下调(P<0.01)。维生素B12治疗反应良好的患儿治疗后血浆中miR-9-1较治疗前显著上调,与健康对照组比较差异无统计学意义。结论 miR-9-1在MMA患儿血浆中显著下调,维生素B12治疗后显著上调,可作为监控MMA病情变化的指标。

Objective To screen out differentially expressed microRNAs（miRNAs） in the plasma of children with methylmalonic acidemia（MMA）,to determine the expression of miR-9-1 in plasma and to preliminarily evaluate the significance of miR-9-1 as a biomarker in MMA.Methods Plasma was obtained from 17 MMA children,10 hyperhomocysteinemia（HHcy） children without MMA（HHcy group）,and 10 normal controls.Of 17 MMA children,12 had HHcy（MMA＋HHcy group）,and 5 had no HHcy（MMAgroup）.The differentially expressed miRNAs were screened out by miRNA microarray.Differentially expressed miR-9-1 was selected,and plasma miR-9-1 levels were determined by RT-PCR.Urine was collected from MMA patients who received vitamin B12 treatment,and plasma miR-9-1 levels were determined by RT-PCR after treatment.Results The miRNA microarray analysis showed that 26 miRNAs were differentially expressed,among which 16 miRNAs（including miR-9-1） were down-regulated over 2 times,while 10 miRNAs were up-regulated over 2 times.The MMA＋HHcy,MMA and HHcy groups had significantly down-regulated miR-9-1 compared with the normal control group（P＆lt;0.01）.The patients who showed a good response to vitamin B12 treatment had significantly increased plasma miR-9-1 levels,without significant difference compared with the normal control group.Conclusions Plasma miR-9-1 is significantly down-regulated in MMA patients,but it is significantly up-regulated after vitamin B12 treatment,suggesting that miR-9-1 may act as a biomarker in monitoring the progression of MMA.[Chin J Contemp Pediatr,2014,16（6）： 629-633]