Quantitative Multimodal Evaluation of Passaging Human Neural Crest Stem Cells for Peripheral Nerve Regeneration

摘要

Peripheral nerve injury is a major burden to societies worldwide, however, current therapy options (e.g. autologous nerve grafts) are unable to produce satisfactory outcomes. Many studies have shown that stem cell transplantation holds great potential for peripheral nerve repair, and human neural crest stem cells (NCSCs), which give rise to a variety of tissues in the peripheral nervous system, are particularly promising. NCSCs are one of the best candidates for clinical translation, however, to ensure the viability and quality of NCSCs for research and clinical use, the effect of in vitro cell passaging on therapeutic effects need be evaluated given that passaging is required to expand NCSCs to meet the demands of transplantation in preclinical research and clinical trials. To date, no study has investigated the quality of NCSCs past the 5^th passage in vivo. In this study, we employed a multimodal evaluation system to investigate changes in outcomes between transplantation with 5^th (p5) and 6^th passage (p6) NCSCs in a 15mm rat sciatic nerve injury and repair model. Using CatWalk gait analysis, gastrocnemius muscle index, electrophysiology, immunohistochemistry, and histomorphometric analysis, we showed that p6 NCSCs demonstrated decreased cell survival, Schwann-cell differentiation, axonal growth, and functional outcomes compared to p5 NCSCs (all p<0.05). In conclusion, p6 NCSCs showed significantly reduced therapeutic efficacy compared to p5 NCSCs for peripheral nerve regeneration.