MicroRNA-223 targets NLRP3 to relieve inflammation and alleviate spinal cord injury.

AIMS

To explore the possible mechanism that microRNA-223 regulates the spinal cord injury as well as the posttranscriptional control of genes after spinal injury.

MATERIALS AND METHODS

Rats contusion spinal cord injury model and microglia model were established and examined by pathological test and the inflammatory cytokines levels were evaluated by RT-PCR. Then microRNA-223 was overexpressed in spinal cord to see the impact on rats with spinal cord injury. The overexpression of microRNA-223 in microglia stimulated by LPS was used to assess the inflammation. Then bioinformatic method combined with luciferase reporter genes were used to detect the target gene of microRNA-223. Then NLRP3, one of the target genes of microRNA-223 were regulated to see the impact on microglia as well as spinal injury rats.

KEY FINDINGS

It showed that microRNA-223 increased after acute spinal injury. However, the suppression of microRNA-223 aggravated the spinal injury as well as the inflammation while the over-expression of microRNA-223 alleviated the spinal injury to some extent, decreased the inflammation and improved nervous system function. In vitro, it was found that the over-expression of microRNA-223 in microglia suppressed inflammation induced by LPS and vice versa. NLRP3 was found the target of microRNA-223. The up-regulation of NLRP3 could diminish the effects of microRNA-223 and aggravated inflammation in microglia.

SIGNIFICANCE

The over-expression of microRNA-223 alleviated the inflammation and improved neuron function. NLRP3 was the downstream target of microRNA-223, the overexpression of which led to severe inflammation in microglia.