Exosome-Mediated siRNA pool Inhibits Axonal Growth Inhibitor in Cortical Neurons of Spinal Cord Injury in Rats

Abstract

Background: As exosomes have been confirmed as a reservoir of siRNAs involved in certain diseases, the current study aims to investigate whether exosomal-siRNA could exert a protective role in spinal cord injury (SCI). Methods and Results: Exosomes in our experiment were isolated from lysosomal membrane-associated protein 2b (Lamp2b) overexpression HEK 293T cells, and purity of exosomes was characterized by the expression of CD9, CD47, and CD63 via western blot. Furthermore, the siRNA pool contains four siRNAs including siRNA-NgR, siRNA-LINGO-1, siRNA-Troy, and siRNA-PTEN was loaded to the exosomes, which indicated a significant role for the siRNA pool in reducing the expression of axon growth inhibitory factors. Upon the completion of loading into exosomes (exo-siRNA pool), the exo-siRNA pool was injected into primary cortical neurons of the SCI model in rats before cell proliferation and Rho expression were determined With the results revealed that purified addition could be applied to future experiments. The exo-siRNA pooled transfection caused downregulation of axon growth suppressors in primary cortical neurons including Nogo receptors (NgR), leucine-rich repeats and immunoglobulin domain-containing protein 1 (LINGO-1), Troy, and phosphatase and tenson homolog (PTEN). Cell proliferation and Rho expression of primary cortical neurons inhibited the expression of axonal growth inhibitors in rats with SCI by transfecting exogenous Sirna. Conclusion: This study confirmed that exosomes derived from Lamp2b overexpression HEK 293T cells facilitated both the recovery of functions and the survival of neurons when being loaded with the siRNA pool.

Nanoparticles in traumatic spinal cord injury: therapy and diagnosis

“…128 Furthermore, several studies have investigated the use of exosomes containing miRNAs such as miR-133b, 129 miR-126, 130,131 miR-216a-5p, 132 miR-544, 133 microRNA-124-3p, 134 miR-25, 135 miR-21 136,137 and siRNA. [138][139][140] Results all favor the use of these miRNAs and siRNA for SCI recovery.…”