Abstract

Erythropoietin-producing hepatoma-amplified sequence (Eph) receptor tyrosine kinases and their cell-surface-bound ligands, the ephrins, function as a unique signaling system triggered by cell to cell interaction and have been shown to mediate neurodevelopmental processes. However, the role of Eph in spinal cord injury (SCI) was unclear. Here, the lentiviral expressing vectors, pGCSIL-green fluorescent protein (GFP) vectors expressing an active small interfering RNA (siRNA) targeting EphB3 sequence were used to determine the effect of RNAi knockdown of EphB3 on function recovery of limb in adult rats by Basso-Beattie-Bresnahan (BBB) scores. Four weeks after intraparenchymal administration of the siRNA into the right lumbar, EphB3 mRNA and protein levels in siRNA group were significantly reduced (P < 0.01) in the spine when compared with the negative group animals. BBB locomotor scores were significantly increased (P < 0.05) in siRNA animals when compared with the control animals. These results indicate that vector-derived siRNAs can effectively produce spatial knockdown of EphB3 gene expression, and this knockdown selectively increased BBB scores of the rats. This preclinical study demonstrates the use of RNAi to target the expression of genes mediating SCI and the therapeutic potential of this approach.

Key word: Spinal cord injury, erythropoietin-producing hepatoma-amplified sequence (Eph) B3 receptors, quantitative reverse transcription polymerase chain reaction (qRT-PCR), EphB3, western-blot, Basso-Beattie-Bresnahan (BBB) scale.