RESUMEN
Objective: To construct a recombinant lentivirus harboring RNAi sequence targeting rat nogo receptor gene and to observe its infection efficiency of 293T cells. Methods: Lentivirus shuttle plasmid containing siNgR199 cDNA was constructed by gene engineering and was used to transfect 293T cells in the presence of packaging plasmids. Forty-eight hours later the supernatant was collected and the titer of virus was determined. The recombinant lentivirus and the standard lentivirus were used to transfect 293T cells at 1 MOI,3 MOI,5 MOI,10 MOI and 20 MOI. Polymerase chain reaction (PCR) was used to detect the recombinant vector; enhanced green fluorescent protein (EGFP) expression was used to determine the titer and the infection rate of the recombinant lentivirus under fluorescent microscope. Results: Restriction endonuclease and PCR analysis confirmed that the siNgR199 cDNA was successfully inserted into the lentivirus vector. The titer of the recombinant lentivirus harboring siNgR199 was 1×108 ifu/ ml and the best MOI was 3. Conclusion: The recombinant lentivirus containing siNgR199 gene has been successfully constructed, which lays a foundation for future axon regeneration in treatment of spinal cord injury.
RESUMEN
<p><b>OBJECTIVE</b>To evaluate the effects of lentiviral vector-mediated RNA interfere gene Nogo receptor (NgR) of rat cortical neurons in repairing spinal cord injury.</p><p><b>METHODS</b>The recombinant-lentiviral vector with small inferring RNA siNgR199 which had been constructed was transfected into rat cortical neuron cells in vitro in 3 multiplicity of infection (MOI). The infection rate was determined with fluorescent microscope, and the target gene was detected by PCR analysis. Then, the recombinant was injected into the cortical motor area of the rats with severe spinal cord injury, and the saline was also injected into other rats with severe spinal cord injury as a match control. The functional recovery of the rats' hindlimb was assessed using BBB score and the nerve fiber of the injured region was observed by nerve tracing.</p><p><b>RESULTS</b>The rate of recombinant infecting rat cortical neuron in vitro exceeded 99%. PCR analysis confirmed that the effect of lentiviral vector-mediated RNA interfering gene NgR of rat cortical neurons in vitro was 61%. Although all rats with spinal cord injury were observed to have the hindlimb functional recovery, these rats injected with recombinant had better hindlimb functional recovery than others showing by more BBB score (P < 0.01). Moreover, it was found that some nerve fiber passed the injured spinal cord region of the rats which were injected with recombinant.</p><p><b>CONCLUSION</b>The recombinant lentiviral vector with siNgR199 which had been constructed is able to promote the growth of nerve fiber and the functional recovery of the rats' hindlimb.</p>