Bone marrow-derived neural crest precursors improve nerve defect repair partially through secreted trophic factors

Haiyan Shi,Mi Shen,Fei Ding,Qianru He,Yaxian Wang,Junling Yang,Yumin Yang,Xiaoli Li,Qi Zhang,Yahong Zhao,Chengbin Xue

doi:10.1186/s13287-019-1517-1

Abstract

BackgroundEmerging evidence suggests that neural crest-derived cells (NCCs) present important functions in peripheral nerve regeneration to correct the insufficiency of autogenous Schwann cells. Postmigratory NCCs have been successfully isolated from adult rat bone marrow in our previous work. In this study, we aim to provide neural crest-derived Schwann cell precursors (SCPs) for repair of nerve defects in adult rats, and partially reveal the mechanisms involved in neuroregeneration of cell therapy.MethodsA clonal cell line of neural crest precursors of rat bone marrow origin (rBM-NCPs) with SCP identity was expanded in adherent monolayer culture to ensure the stable cell viability of NCPs and potentiate the repair of nerve defects after rBM-NCPs implantation based on tissue engineering nerve grafts (TENG). Here the behavioral, morphological, and electrophysiological detection was performed to evaluate the therapy efficacy. We further investigated the treatment with NCP-conditioned medium (NCP-CM) to sensory neurons after exposure to oxygen-glucose-deprivation (OGD) and partially compared the expression of trophic factor genes in rBM-NCPs with that in mesenchymal stem cells of bone marrow origin (rBM-MSCs).ResultsIt was showed that the constructed TENG with rBM-NCPs loaded into silk fibroin fiber scaffolds/chitosan conduits repaired 10-mm long sciatic nerve defects more efficiently than conduits alone. The axonal regrowth, remyelination promoted the reinnervation of the denervated hind limb muscle and skin and thereby alleviated muscle atrophy and facilitated the rehabilitation of motor and sensory function. Moreover, it was demonstrated that treatment with NCP-CM could restore the cultured primary sensory neurons after OGD through trophic factors including epidermal growth factor (EGF), platelet-derived growth factor alpha (PDGFα), ciliary neurotrophic factor (CNTF), and vascular endothelial growth factor alpha (VEGFα).ConclusionsIn summary, our findings indicated that monolayer-cultured rBM-NCPs cell-based therapy might effectively repair peripheral nerve defects partially through secreted trophic factors, which represented the secretome of rBM-NCPs differing from that of rBM-MSCs.

Highlights

Emerging evidence suggests that neural crest-derived cells (NCCs) present important functions in peripheral nerve regeneration to correct the insufficiency of autogenous Schwann cells
The induction of differentiation displayed that the derived Schwann cells from rBM-Neural crest precursor (NCP) became elongated long-spindle shape and side-by-side alignment (Fig. 1d), as well as positive expression of Schwann cell-specific markers, including S100β, Glial fibrillary acidic protein (GFAP) and p75 (Fig. 1e)
After the characterization of the monolayer-cultured rBM-NCPs, cells were labeled with Qdot-tracker 565 and detected immediately in vitro, and the labeled cells were still detectable in frozen sections of tissue engineering nerve grafts (TENG) after transplantation for 1 week (Fig. 1f)

Summary

Introduction

Emerging evidence suggests that neural crest-derived cells (NCCs) present important functions in peripheral nerve regeneration to correct the insufficiency of autogenous Schwann cells. Schwann cell precursors (SCPs) are usually derived from neural crest cells (NCCs), emerged in contact with neuronal axons during peripheral nerve development [1]. SCPs present many important functions for peripheral nerve development and regeneration, including neuronal survival, axonal growth, myelination, nerve fasciculation, and target innervation. They may differentiate into various neural cells (e.g., glia, endoneurial fibroblasts, visceral neurons) and non-neural-like cells (e.g., mesenchymal stromal cells) [4]. The repair type Schwann cells enable to control the infiltration of inflammatory cells across the blood-nerve barrier, clear myelin, and axonal debris; regulate the extracellular matrix balance; and produce cytokines to guide axonal regrowth across the nerve gap

Objectives

Methods

Results

Discussion

Conclusion