Transplantation of N-Acetyl Aspartyl-Glutamate Synthetase-Activated Neural Stem Cells after Experimental Traumatic Brain Injury Significantly Improves Neurological Recovery
Background/Aims: Neural stem cells (NSCs) hold considerable potential as a therapeutic tool for repair of the damaged nervous system. In the current study, we examined whether transplanted N-acetyl aspartyl-glutamate synthetase (NAAGS)-activated NSCs (NAAGS/NSCs) further improve neurological recovery following traumatic brain injury (TBI) in Sprague-Dawley rats. Methods: Animals received TBI and stereotactic injection of NSCs, NAAGS/NSCs or phosphate buffered saline without cells (control) into the injured cortex. NAAGS protein expression was detected through western blot analysis. Dialysate NAAG levels were analyzed with radioimmunoassay. Cell apoptosis was detected via TUNEL staining. The expression levels of specific pro-inflammatory cytokines were detected with enzyme-linked immunosorbent assay. Results: Groups with transplanted NSCs and NAAGS/NSCs displayed significant recovery of the motor behavior, compared to the control group. At 14 and 21 days post-transplantation, the motor behavior in NAAGS/NSC group was significantly improved than that in NSC group (p<0.05). Additionally, transplanted NAAGS/NSCs inhibited cell apoptosis and the expression levels of specific pro-inflammatory cytokines, including interleukin-1β, interleukin-6 and tumor necrosis factor-α. Conclusion: Our results collectively demonstrate that NAAGS/NSCs provide a more powerful autoplastic therapy for the injured nervous system.