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

摘要:

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。

Abstract:

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 (MMA group). 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<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.