Effect of GM-CSF and NGF on the neural cell death after spinal cord injury of rats

Abstract

Recently, we reported that GM-CSF showed therapeutic effects oil the spinal cord injury(SCI) in rat model possibly via its anti-apoptotic activity in the nervous system. This Study investigated the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) with nerve growth factor(NGF) on the repair of spinal cord injury(SCI). GM-CSF treatment in rat SCI model, either with or without intraspinal administration of NGF, reduced the apoptotic event(TUNEL assay). Administration of GM-CSF and/or NGF reduced the expression of pro-apoptotic protein(Bax), while further induced that of the anti-apoptotic protein(Bcl-2). By the BBB scoring system, the administration of GM-CSF resulted in the behavioral recovery at 4 and 7 days after injury. However. NGF had no significant effect oil the behavioral recovery. Overall, GM-CSF was shown to exert neuroprotective effect after SCI by regulating the expression of apoptosis related genes, but no cooperative effect with intraspinal administration of NGF was observed. This result suggests that GM-CSF and NGF played redundant roles during the recovery of SCI and further optimization in the therapeutic strategy is necessary.