Up‐regulation of miR‐26a promotes neurite outgrowth and ameliorates apoptosis by inhibiting PTEN in bupivacaine injured mouse dorsal root ganglia

Abstract

Local anesthetic of bupivacaine may inhibit neurite outgrowth and induce apoptosis in mouse dorsal root ganglia (DRG) neurons. In this work, we intended to investigate the functional role of microRNA 26a (miR-26a) in regulating bupivacaine-induced nerve injury in DRG neurons. DRG neurons were extracted from C57BL/6 mice and cultured in vitro. Bupivacaine was applied in vitro and it induced apoptosis, inhibited neurite growth, and significantly down-regulated miR-26a gene in DRG neurons. MiR-26a mimic was then used to up-regulate miR-26a expression in DRG neurons. We found that miR-26a up-regulation promoted neurite outgrowth and reduced apoptosis in bupivacaine-injured DRG neurons. Luciferase assay and Western blot confirmed that Phosphatase and tensin homolog (PTEN) was down-stream target of miR-26a in DRG neurons. Ectopic PTEN up-regulation was then able to reverse the protective effect of miR-26a overexpression on bupivacaine-induced nerve injury in DRG neurons. Overall, this work demonstrated that miR-26a had a functional role in regulating bupivacaine-induced nerve injury in DRG neurons. Up-regulating miR-26a to suppress PTEN signaling pathway may be an effective method to protect local anesthetic-induced nerve injury in spinal cord.

Spatiotemporal regulation of GSK3β levels by miRNA-26a controls axon development in cortical neurons

“…The search for a molecular mechanism that elucidates the capacity of miR-26a to control both neuron polarity and axon outgrowth led us to investigate PTEN and GSK3β, which, respectively, bear three and two highly conserved miR-26a-binding site sequences in their 3′UTRs (Fig. S3A,B) and have been previously described as functional targets of miR-26a (Cui et al, 2015;Jiang et al, 2015;Li and Sun, 2013). Knockdown of GSK3β and the use of specific inhibitors cause the formation of multiple axons (Gartner et al, 2006;Jiang et al, 2005).…”

Long noncoding RNA BDNF-AS regulates ketamine-induced neurotoxicity in neural stem cell derived neurons

“…The neurite outgrowth assay to compare neuronal growth among mouse embryonic neural stem cells -derived neurons was performed according to a previously described method [17]. Briefly, differentiation culture was fixed by 4% PFA PBS for 30 mins, then blocked by PBS with 1% goat serum and 0.1% Triton (Sigma-Aldrich, USA) for 1 h. Mouse monoclonal tuj1 antibody and a rabbit polyclonal anti-NeuN antibody (1:500, Sigma Aldrich, USA) were applied overnight at 4 C, followed by the application of Alex567 goat-anti-mouse and Alex488 goat-anti-rabbit secondary antibodies (1: 5000, Thermo Fisher Scientific, USA) for 2 h at room temperature.…”

The roles of extracellular vesicle microRNAs in the central nervous system

“…In the mature CNS, miRNAs also contribute to maintaining health and homeostasis. For example, many studies have implicated miR‐26a in several neuronal processes, including the regulation of neuron morphology, axon regeneration, and synapse development and plasticity via directly targeting Glycogen synthase kinase 3β (GSK‐3β; Jiang et al, ), Phosphatase and tensin homolog (PTEN; Cui, Xu, Qiu, & Fan, ; Li & Sun, ), Brain‐derived neurotrophic factor (BDNF; Caputo et al, ) and ribosomal S6 kinase 3 (RSK3; Gu et al, ). A reduction in levels of miR‐26a was also recently implicated in brain ageing (Zhang et al, c).…”