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Abstract: MicroRNAs (miRNAs) are a novel class of small non-coding RNAs that regulate gene expression at the post-transcriptional level. Here we report early alterations of miRNAs expression following rat sciatic nerve injury using microarray analysis. We harvested dorsal root ganglia (DRG) tissues and identified 19 miRNAs that showed significant changes at four early time points after sciatic nerve transection. Subsequently, miR-188 and miR-500 microarray results were verified by real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The bioinformatics analysis indicated that the potential targets for these miRNAs were involved in the intracellular signaling cascade, the regulation of signal transduction, the regulation of cellular process and the response to cAMP that were known to play important roles in mobilizing the inherent capacity for neurite outgrowth and promoting regeneration during the early phase of sciatic nerve injury. Our results show that abnormal expression of miRNAs may contribute to illustrate the molecular mechanisms of nerve regeneration and miRNAs are potential targets for therapeutic interventions that may enhance intrinsic regenerative ability. [Copyright &y& Elsevier]

Abstract: Dorsal root ganglia (DRG) neurons spontaneously undergo robust neurite growth after axotomy. Long noncoding RNAs (lncRNAs) are an important class of pervasive genes involved in a variety of biological functions. However, the functions of lncRNAs in the regulation of responses of DRG neurons to injury stimuli remain untested. Here, lncRNA microarray analysis was performed to profile the lncRNAs in L4–L6 DRGs following rat sciatic nerve resection. The 105 lncRNAs were identified to be differentially expressed at 0, 1, 4, 7 d post injury. A coexpression network of 24 down-regulated lncRNAs and coding genes was constructed, and 115 targets of these 24 lncRNAs were found to be mainly involved in cell phenotype modulation, including glial cell migration, purinergic nucleotide receptor signaling pathway, vasodilation, regulation of multi-organism process, and neuropeptide signaling pathway, and also to be potentially associated with several key regeneration signaling pathways, including MAPK signaling pathway, and neuroactive ligand–receptor interaction. LncRNA BC089918 was selected from 24 down-regulated lncRNAs for validation by quantitative real-time polymerase chain reaction and in situ hybridization. And silencing of BC089918 with small interfering RNAs indicted that the lncRNA had a particular promoting effect on neurite outgrowth. Our data demonstrated a distinct involvement of lncRNAs in DRGs after nerve injury, thus contributing to illustration of molecular mechanisms responsible for nerve regeneration. [Copyright &y& Elsevier]