Effect of adenovirus-mediated RNA interference of IL-1β expression on spinal cord injury in rats

Study design: We introduced an adenoviral vector expressing interleukin-1 beta (IL-1 beta) small-hairpin RNA (shRNA) into the injured spinal cords to evaluate the therapeutic potential of IL-1 beta downregulation in a rat model of spinal cord injury (SCI). Objectives: The purpose of this study was to investigate the possible protective effects of the IL-1 beta downregulation on traumatic SCI in rats. Setting: Department of Orthopedic Surgery, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, People's Republic of China. Methods: An adenoviral shRNA targeting IL-1 beta was constructed and injected at the T12 section 7 days before SCI. The rats' motor functions were evaluated by the Basso-Beattie-Bresnahan (BBB) rating scale. Immunofluorescence, enzyme-linked immunosorbent assay, flow-cytometric analysis and western blots were also performed. Results: Animals downregulating IL-1 beta had significantly better recovery of locomotor function and less neuronal loss after SCI. In addition, IL-1 beta downregulation significantly decreased tumor necrosis factor-alpha (TNF-alpha) level and Bax expression, reduced the activity of caspase-3 and increased Bcl-2 expression after SCI. Conclusion: This study demonstrated that the IL-1 beta downregulation may have potential therapeutic benefits for both reducing secondary damages and improving the outcomes after traumatic SCI.