Serum exosomal microRNA transcriptome profiling in subacute spinal cord injured rats.

MicroRNAs (miRNAs) are involved in a series of pathology of spinal cord injury (SCI). Although, locally expressed miRNAs have advantages in studying the pathological mechanism, they cannot be used as biomarkers. The "free circulation" miRNAs can be used as biomarkers, but they have low concentration and poor stability in body fluids. Exosomal miRNAs in body fluids have many advantages comparing with free miRNAs. Therefore, we hypothesized that the specific miRNAs in the central nervous system might be transported to the peripheral circulation and concentrated in exosomes after injury. Using next-generation sequencing, miRNA profiles in serum exosomes of sham and subactue SCI rats were analyzed. The results showed that SCI can lead to changes of serum exosomal miRNAs. These changed miRNAs and their associated signaling pathways may explain the pathological mechanism of suacute SCI. More importantly, we found some valuable serum exosomal miRNAs for diagnosis and prognosis of SCI.