Screening and characterizing the effects of mmu_circ_0000296 on spinal cord injury

Spinal cord injury (SCI) is a common pathologic disorder that often presents with sensory and motor deficits, severely affecting patients' daily lives. Circular RNAs (circRNAs), a class of non-coding RNAs, have been reported to be involved in regulating the development of SCI. We used RNA sequencing technology and bioinformatics analysis to find the expression and regulation patterns of circRNAs and mRNAs in a mouse model of SCI, from which we screened the potential RNA-mmu_circ_0000296 that affects the progression of SCI in the acute phase. Based on STRING, ENCORI, miRTarBase database and Cytoscape software to construct the relational network of endogenous competing RNAs (ceRNAs) and protein-protein interaction (PPI) network. Finally, in order to validate the above bioinformatics results, the differential expression of circ_0000296 was verified in mouse SCI model and LPS-induced cell model, respectively. Not only that, in in vitro experiments, we found that circ_0000296 overexpression could inhibit microglia polarization toward M1 type, reduce inflammation level, and then inhibit neuronal apoptosis. These findings will help to elucidate and refine the effects of circRNAs on the pathophysiological progression of spinal cord injury and suggest that mmu_circ_0000296 may be one of the targets for spinal cord injury therapy. To screen circRNAs affecting spinal cord injury, we established SCI mouse models. 3 control mice underwent laminectomy at the T10 level without spinal cord injury, and the other 3 experimental mice were placed on the spinal cord impingement platform after laminectomy at the T10 level, and the spinal cord was moderately contused at the T10 level using a modified Allen weight descender (10 g weight with a vertical height of 20 mm). Following surgery, daily bladder massages were given until full spontaneous or voluntary urination and daily antibiotics were given for three days. For the SCI model consistency, the following criteria were required for inclusion: (I) mice weighing between 20 and 25 g; (II) 10 g weight and 20 mm vertical height requirements for weight reduction devices; (III)tail wagging, hind limb twitching right after SCI, and flaccid paralysis of the hind limbs when awake. Exclusion criteria included: (I) The animals weight and age were below average. (II) During a laminectomy, the spinal cord unintentionally suffered damage. (III) The mice s hindlimbs could still move after they emerged from anesthesia. 6 mice were executed on the 2nd day after surgery, and spinal cord tissues about 1 cm long around the T10 level were taken for high-throughput RNA sequencing.