嗅鞘细胞移植治疗脊髓损伤的研究进展

Advancement in the treatment of spinal cord injury by olfactory ensheathing cells transplantation

中文关键词:  华通胶间充质干细胞  共培养  诱导分化  髓核细胞

英文关键词:Wharton′s jelly-derived mesenchymal stem cells  Coculture  Differentiation  Nucleus pulposus cells

中文摘要:

  脊髓损伤（spinal cord injury，SCI）的治疗一直是医学界的难题，现今临床上仍无确实有效的治疗方法。目前，SCI修复的研究策略主要有以下几方面：药物治疗、细胞移植治疗、组织移植治疗、基因治疗以及联合治疗等。近年来细胞移植治疗被广泛研究，包括胚胎干细胞（embryonic stem cells，ESCs）、雪旺氏细胞（Schwann cells， SCs）、嗅鞘细胞（olfactory ensheathing cells，OECs）、神经干细胞（neural stem cells，NSCs）、骨髓间充质干细胞（bone marrow stromal cells，BMSCs）、脐血细胞（umbilical cord blood cells，UCBCs）等，其中OECs以独特的生物学特性和功能引起医学界广泛关注。笔者就OECs移植治疗SCI的研究进展综述如下。

英文摘要:

  【Abstract】 Objectives: To investigate the differentiation of human Wharton′s jelly-derived mesenhymal stem cells(WJMSCs) into nucleus pulposus-like cells by coculture with cell-cell contact in vitro. Methods: Umbilical cord was obtained from normal birth, and the mesenchyamal stem cells were isolated from the umbilical cord Wharton′s jelly. Human nucleus pulposus cells(NPCs) were isolated from human intervertebral nucleus pulposus. WJMSCs were taken for flow cytometric analysis(CD73/CD90/CD105/CD34/CD45/HLA-ABC/HLA-DR). Fluorescent labeled WJMSCs and no-labled NPCs were cocultured for 7 days by cell-cell contact method. Cells were seeded at ratio of 1∶1. WJMSCs cultured alone served as controls. MoFlo high-speed cell sorting was conducted to separate fluorescent labeled WJMSCs and NPCs after coculture. Total RNA was extracted from cells using Trizol reagent. After the cDNA was obtained by reverse transcription, relative gene expressions of type Ⅰ collagen, type Ⅱ collagen, type Ⅵ collagen, aggrecan, SOX-9 and versican were determined by Real-Time PCR and normalized to the GAPDH housekeeping gene. WJMSCs cultured alone served as controls. The 2-ΔΔCt value was then used to calculate relative expression of each target gene. Results: WJMSCs were isolated from human umbilical cord and expanded as primary cultures. After attachment, the cells gradually spread out and were shown as fibroblast-like morphology. According to the immunophenotypic analysis of flow cytometry, the WJMSCs expressed CD73, CD90, CD105, and HLA-ABC, but did not express CD34, CD45 and HLA-DR. While WJMSCs and NPCs were cocultured with cell-cell contact, SOX-9, type Ⅱ collagen and aggrecan mRNA increased significantly in WJMSCs(P<0.01). There were no significant changes in type Ⅰ collagen, type Ⅵ collagen and versican mRNA expression(P>0.05). Conclusions: WJMSCs display the characteristics of mesenchymal stem cells. Coculture of NPCs and WJMSCs with cell-cell contact can induce WJMSCs differentiating into a NPCs phenotype within 7 days, which indicates that WJMSCs may be a promising seed cell for tissue engineering therapies or cell-based therapies for degenerated intervertebral discs.