目的：探讨microRNA-29b (miR-29b)在肌萎缩侧索硬化（amyotrophic lateral sclerosis，ALS）中的表达水平及其在该病诊断中的可能价值。方法：留取16只SOD1-G93A ALS模型鼠和16只野生型鼠脑皮质、脊髓、前肢肌肉组织和血浆，提取microRNA，采用实时荧光定量聚合酶链反应（real-time quantitative polymerase chain reaction，RT-qPCR）方法检测miR-29b的表达量，并通过受试者工作特征曲线（receiver operator characteristic curve，ROC）评估SOD1-G93A ALS模型鼠miR-29b对于ALS的诊断价值。结果：以U6 snRNA为内参，实验组SOD1-G93A ALS模型鼠脑皮质miR-29b相对表达量显著高于对照组水平(P=0.001)。按周龄分组，8、12和16周龄实验组SOD1-G93A ALS模型鼠脑皮质miR-29b的相对表达量显著高于对照组水平（3个不同周龄的实验组vs.对照组显著性检验分别为P=0.044、P=0.018、P=0.045）。通过SOD1-G93A ALS模型鼠脑皮质miR-29b的相对表达量（以U6 snRNA为内参）对ALS进行诊断时，ROC曲线下面积（area under the curve，AUC）为0.885，如果以0.185 6为诊断临界值，灵敏度和特异度均较高，分别为92.9%和71.4%。结论：miR-29b可能会成为早期诊断ALS的检测指标。

Objective：To investigate microRNA-29b (miR-29b) expression in cerebral cortex, spinal cord, fore limb muscle, and serum of SOD1-G93A amyotrophic lateral sclerosis (ALS) mice, and to identify the biomarker and to assess diagnostic values for ALS. Methods: Cerebral cortex, spinal cord, fore limb muscle and serum from 16 SOD1-G93A ALS mice and 16 wild-type mice were taken and then microRNA extracted, detecting the expression of miR-29b by real-time quantitative polymerase chain reaction (RT-qPCR). The diagnostic performance of miR-29b for ALS was estimated by the receiver operating characteristic (ROC) curve. Results: The results from the validation indicated that the differences in miR-29b between the cerebral cortex of SOD1-G93A ALS and the healthy control subjects were statistically significant (P=0.001). Meanwhile, the expressions 8, 12, and 16 weeks later were higher than those of the controls (ALS vs. Control: 8 weeks, P=0.044; 12 weeks, P=0.018; 16 weeks, P=0.045). When the relative expression level of miR-29b was used to diagnose ALS in SOD1-G93A ALS mice, the area under the ROC (area under the curve, AUC) was 0.885, if the diagnostic threshold was set at 0.185 6, the sensitivity and specificity were 92.9% and 71.4%. Conclusion: MiR-29b may act as medical monitoring indices of ALS in early time.