The Differentiation Stage of Transplanted Stem Cells Modulates Nerve Regeneration

Ching-Wen Huang,Mu-Ming Poo,Shyam Patel,Wen-Chin Huang,Flavia Fernandes Ferreira da Silva,Leon J. Nesti,Xuefeng Qiu,Song Li,Aijun Wang

doi:10.1038/s41598-017-17043-4

Abstract

In regenerative medicine applications, the differentiation stage of implanted stem cells must be optimized to control cell fate and enhance therapeutic efficacy. We investigated the therapeutic potential of human induced pluripotent stem cell (iPSC)-derived cells at two differentiation stages on peripheral nerve regeneration. Neural crest stem cells (NCSCs) and Schwann cells (NCSC-SCs) derived from iPSCs were used to construct a tissue-engineered nerve conduit that was applied to bridge injured nerves in a rat sciatic nerve transection model. Upon nerve conduit implantation, the NCSC group showed significantly higher electrophysiological recovery at 1 month as well as better gastrocnemius muscle recovery at 5 months than the acellular group, but the NCSC-SC group didn’t. Both transplanted NCSCs and NCSC-SCs interacted with newly-growing host axons, while NCSCs showed better survival rate and distribution. The transplanted NCSCs mainly differentiated into Schwann cells with no teratoma formation, and they secreted higher concentrations of brain-derived neurotrophic factor and nerve growth factor than NCSC-SCs. In conclusion, transplantation of iPSC-NCSCs accelerated functional nerve recovery with the involvement of stem cell differentiation and paracrine signaling. This study unravels the in vivo performance of stem cells during tissue regeneration, and provides a rationale of using appropriate stem cells for regenerative medicine.

Highlights

To address these critical issues of stem cell therapies, in this study, we investigated the impact of different stages of induced pluripotent stem cell (iPSC)-derived neural lineage cells on peripheral nerve regeneration in a rat sciatic nerve transection model
Human dermal fibroblasts were reprogrammed with Yamanaka factors delivered by electroporation to generate integration-free human iPSCs (Fig. 1A), and the fully characterized iPSC lines were used to derive Neural crest stem cells (NCSCs) (Fig. 1B) by using an optimized protocol
We investigated whether the differentiation stage of transplanted iPSC-derived neural lineage cells could impact functional nerve recovery in vivo

Summary

Introduction

We and others have shown that NCSCs can be differentiated from iPSCs33–35, and further differentiate into cell types of all three germ layers, e.g., neurons, Schwann cells, vascular smooth muscle cells (SMCs), bone cells, cartilage cells, melanocytes and endocrine cells, which makes NCSCs a valuable stem cell source for tissue regeneration and an ideal model system to study the lineage commitment and therapeutic potential of stem cells. Previous studies have shown that transplantation of iPSC-induced NCSCs in nerve conduits promotes nerve regeneration at 1 month[36], but those iPSCs are not integration-free and the underlying mechanisms are not clear. The therapeutic effects of the cells at various differentiation stages were investigated and compared in a rat sciatic nerve transection model wherein the nerve injury was bridged with a poly(L-lactide-co-caprolactone) (PLCL) nanofibrous conduit. The mechanisms of transplanted cells-induced nerve regeneration, including in vivo differentiation and paracrine signaling, were further studied

Methods

Results

Conclusion