Cacna2d2 inhibits axonal regeneration following surgical decompression in a rat model of cervical spondylotic myelopathy.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is a clinically symptomatic condition due to spinal cord compression, leading to spinal cord dysfunction. Surgical decompression is the main treatment of CSM, but the mechanisms of axonal regeneration after surgical decompression are still fragmentary. METHODS: In a rat model of CSM, the cacna2d2 (α2δ2) expression levels in anterior horn of spinal cord were observed following compression and decompression by western blot and immunofluorescence. The expression levels of 5 hydroxytryptamine (5HT) and GAP43 were also analyzed by immunofluorescence. Furthermore, gabapentin intervention was performed for 4 weeks after decompression to analyze the changes of behaviors and anterior horn of spinal cords. RESULTS: Following decompression, the expression levels of α2δ2 in the anterior horn of spinal cord were decreased, but the expression levels of 5HT andGAP43 were increased. Compared with the vehicle treated rats, gabapentin treatment for 4 weeks ameliorated the behaviors of rats and improved the damaged anterior horn of spinal cord. Besides, inhibition of α2δ2 through gabapentin intervention enhanced the axonal regeneration in the anterior horn of damaged spinal cord. CONCLUSIONS: Inhibition of α2δ2 could enhance axonal recovery in anterior horn of damaged spinal cord induced by CSM after surgical decompression, providing a potential method for promoting axon regeneration following surgery.

Long noncoding RNA NORAD regulates cancer cell proliferation and migration in human osteosarcoma by endogenously competing with miR-199a-3p.

In this study, we evaluated the expressions and functions of a long noncoding RNA (lncRNA), Noncoding RNA activated by DNA damage (NORAD) in human osteosarcoma. NORAD expressions were evaluated by qRT-PCR in in vitro osteosarcoma cell lines and in vivo clinical specimens. SiRNA-induced NORAD downregulation was conducted in Saos-2 and 143B cells, and the functional effects of NORAD downregulation on osteosarcoma cells were evaluated by CCK-8 proliferation assay, 24-well transwell invasion assay and in vivo tumor explant assay, respectively. The possibility of NORAD endogenously competing microRNA target, hsa-miR-199a-3p was examined by dual-luciferase reporter assay and qRT-PCR. Then, hsa-miR-199a-3p was downregulated in NORAD-inhibited osteosarcoma cells to examine its role in regulating NORAD inhibition induced cancer suppression in osteosarcoma cells. NORAD was found to be significantly overexpressed in both osteosarcoma cells and osteosarcoma tumors. In Saos-2 and 143B cells transfected with NORAD-specific siRNA, their proliferation, invasion, and in vivo explant growth were all markedly suppressed. Hsa-miR-199a-3p was confirmed to be the competing target of NORAD. Its downregulation in Saos-2 and 143B cells inversely augment proliferation and invasion that were initially suppressed by NORAD-downregulation. The results of our study show that NORAD plays an important role in regulating cancer cell functions of osteosarcoma, possibly through endogenously competing with hsa-miR-199a-3p.

TXNIP Participated in NLRP3-Mediated Inflammation in a Rat Model of Cervical Spondylotic Myelopathy.

Background: Cervical spondylotic myelopathy (CSM) is a spinal cord disease caused by cervical disc degeneration and related pathological changes. Cervical spondylotic myelopathy may result from inflammation responses and neuronal damage. Thioredoxin-interacting protein (TXNIP)/NOD-like receptor protein 3 (NLRP3) signaling promotes inflammation. However, the effects of TXNIP/NLRP3 on the pathogenesis of CSM have not been reported. Methods: A rat model of chronic cervical cord compression was established to observe changes in the levels of of TNXIP/NeuN and NLRP3/NeuN expression in the damaged anterior horn of the spinal cord following progression of CSM. Rats were injected with TXNIP small interfering RNA (siRNA) and scrambled control to determine the effects of TXNIP inhibition on NLRP3-mediated inflammation in rats with CSM. Behaviors effects and the expression of NLRP3 and pro-caspase-1 in the damaged spinal cord were evaluated. Results: The expression levels of TXNIP and NLRP3 were significantly increased in the damaged anterior horn of the spinal cord following CSM. Injection of TXNIP siRNA significantly improved behavioral measures and decreased apoptosis in the damaged anterior horn of spinal cord. Furthermore, the levels of NLRP3 and pro-caspase-1 in the lesioned area were reduced by the TXNIP siRNA injection. Conclusion: Thioredoxin-interacting protein participated in NLRP3 mediated inflammation in a rat model of CSM, which indicated that TXNIP may be a potential therapeutic target in improving CSM.