Circular RNAs (circRNAs) are a class of conserved, endogenous non-coding RNAs 
that are involved in transcriptional and post-transcriptional gene regulation 
and are highly enriched in the nervous system. They participate in the survival 
and differentiation of multiple nerve cells, and may even promote the recovery 
of neurological function after stroke. However, their role in the inflammatory 
response after spinal cord injury remains unclear. In the present study, we 
established a mouse model of T9 spinal cord injury using the modified Allen's 
impact method, and identified 16,013 circRNAs and 960 miRNAs that were 
differentially expressed after spinal cord injury. Of these, the expression 
levels of circPrkcsh were significantly different between injured and 
sham-treated mice. We then treated astrocytes with tumor necrosis factor-α in 
vitro to simulate the inflammatory response after spinal cord injury. Our 
results revealed an elevated expression of circPrkcsh with a concurrent decrease 
in miR-488 expression in injured cells. We also found that circPrkcsh regulated 
the expression of the inflammation-related gene Ccl2. Furthermore, in tumor 
necrosis factor-α-treated astrocytes, circPrkcsh knockdown decreased the 
expression of Ccl2 by upregulating miR-488 expression, and reduced the secretion 
of inflammatory cytokines in vitro. These findings suggest that differentially 
expressed circRNAs participate in the inflammatory response after spinal cord 
injury and act as the regulators of certain microRNAs. Furthermore, circPrkcsh 
may be used as an miR-488 sponge to regulate Ccl2 expression, which might 
provide a new potential therapy for SCI. The study was approved by the Animal 
Ethics Committee of Shandong University of China (approval No. KYLL-20170303) on 
March 3, 2017.