Biological Technologies, Pfizer Global Research and Development, Cambridge, Massachusetts, United States of America.
PLoS One. 2011 Mar 14;6(3):e17670. doi: 10.1371/journal.pone.0017670.
Neuropathic pain resulting from nerve lesions or dysfunction represents one of the most challenging neurological diseases to treat. A better understanding of the molecular mechanisms responsible for causing these maladaptive responses can help develop novel therapeutic strategies and biomarkers for neuropathic pain. We performed a miRNA expression profiling study of dorsal root ganglion (DRG) tissue from rats four weeks post spinal nerve ligation (SNL), a model of neuropathic pain. TaqMan low density arrays identified 63 miRNAs whose level of expression was significantly altered following SNL surgery. Of these, 59 were downregulated and the ipsilateral L4 DRG, not the injured L5 DRG, showed the most significant downregulation suggesting that miRNA changes in the uninjured afferents may underlie the development and maintenance of neuropathic pain. TargetScan was used to predict mRNA targets for these miRNAs and it was found that the transcripts with multiple predicted target sites belong to neurologically important pathways. By employing different bioinformatic approaches we identified neurite remodeling as a significantly regulated biological pathway, and some of these predictions were confirmed by siRNA knockdown for genes that regulate neurite growth in differentiated Neuro2A cells. In vitro validation for predicted target sites in the 3'-UTR of voltage-gated sodium channel Scn11a, alpha 2/delta1 subunit of voltage-dependent Ca-channel, and purinergic receptor P2rx ligand-gated ion channel 4 using luciferase reporter assays showed that identified miRNAs modulated gene expression significantly. Our results suggest the potential for miRNAs to play a direct role in neuropathic pain.
神经病理性疼痛是由神经损伤或功能障碍引起的，是最难治疗的神经疾病之一。更好地了解导致这些适应性反应的分子机制，可以帮助开发治疗神经病理性疼痛的新策略和生物标志物。我们对脊髓神经结扎（SNL）后 4 周大鼠背根神经节（DRG）组织进行了 miRNA 表达谱研究，SNL 是一种神经病理性疼痛模型。TaqMan 低密度阵列鉴定出 63 种 miRNA 的表达水平在 SNL 手术后发生了显著改变。其中，59 种 miRNA 下调，并且同侧 L4 DRG 而不是受损的 L5 DRG 显示出最显著的下调，这表明未受损传入神经中的 miRNA 变化可能是神经病理性疼痛发展和维持的基础。TargetScan 用于预测这些 miRNA 的 mRNA 靶标，发现具有多个预测靶位的转录本属于神经重要途径。通过采用不同的生物信息学方法，我们确定了神经突重塑作为一个显著调节的生物学途径，并且一些预测通过针对调节分化的 Neuro2A 细胞中神经突生长的基因的 siRNA 敲低得到了证实。在电压门控钠离子通道 Scn11a 的 3'-UTR、电压依赖性钙通道的 alpha 2/delta1 亚基和嘌呤能受体 P2rx 配体门控离子通道 4 的预测靶位点的体外验证中，使用荧光素酶报告基因检测显示鉴定出的 miRNA 显著调节基因表达。我们的结果表明，miRNA 有可能在神经病理性疼痛中发挥直接作用。
