Therapeutic Potential of Lentivirus-Mediated shRNA Delivery in Spinal Cord Injury

Traumatic spinal cord injury (SCI) results in an initial primary injury, followed by secondary events that exacerbate the damage. As a key factor of secondary injury, inflammation is initiated in part by the rapid influx of circulating immune cells. These cells begin to release various inhibitory factors, which can contribute to additional neuronal cell death, demyelination, and functional deficits following SCI. P38 mitogen-activated protein kinase (MAPK) is specifically activated after SCI, which results in the production of multiple factors that inhibit axon growth and activate nociceptors, contributing to various functional deficits. Short hairpin RNA (shRNA) interference is an efficient tool for the specific knockdown of disease-related gene expression after SCI. In this study, P38 MAPK-shRNA encoded-lentiviral vectors (LV-shP38) were delivered into the injured spinal cord to silence downstream P38 MAPK signaling. We performed qRT-PCR to investigate the effects of LV-shP38 from the spinal cord, dorsal root ganglia, and spleen. The data indicate that LV-shP38 significantly increases the expression of pro-regenerative factors, while reducing the expression of pro-inflammatory factors compared to control group (luciferase encoded lentiviral vector). Our LV-mediated gene silencing therapy will enable efficient and extended delivery of shRNA, thereby overcoming current hurdles to successfully introduce RNA interference-based therapies into the clinic.