Transplantation of adult monkey neural stem cells into a contusion spinal cord injury model in rhesus macaque monkeys.

Objective: Currently, cellular transplantation for spinal cord injuries (SCI) is the subject of numerous preclinical studies. Among the many cell types in the adult brain, there is a unique subpopulation of neural stem cells (NSC) that can self-renew and differentiate into neurons. The study aims, therefore, to explore the efficacy of adult monkey NSC (mNSC) in a primate SCI model. Materials and Methods: In this experimental study, isolated mNSCs were analyzed by flow cytometry, immunocytochemistry, and RT-PCR. Next, BrdU-labeled cells were transplanted into a SCI model. The SCI animal model was confirmed by magnetic resonance imaging (MRI) and histological analysis. Animals were clinically observed for 6 months. Results: Analysis confirmed homing of mNSCs into the injury site. Transplanted cells expressed neuronal markers (TubIII). Hind limb performance improved in transplanted animals based on Tarlov's scale and our established behavioral tests for monkeys. Conclusion: Our findings have indicated that mNSCs can facilitate recovery in contusion SCI models in rhesus macaque monkeys. Additional studies are necessary to determine the improvement mechanisms after cell transplantation.