Differentiation of mesenchymal stem cells transplanted to a rabbit degenerative disc model - Potential and limitations for stem cell therapy in disc regeneration
Differentiation of mesenchymal stem cells transplanted to a rabbit degenerative disc model - Potential and limitations for stem cell therapy in disc regeneration
复制标题
DOI：
10.1097/01.brs.0000184365.28481.e3
复制
发表时间：
2005-11-01
期刊：
影响因子：
3
通讯作者：
Hotta, T
中科院分区：
文献类型：
--
作者：
Sakai, D;Mochida, J;Hotta, T
研究设计。目的探讨兔退变髓核内移植间充质干细胞(MSCs)的体内分化状况。评估骨髓间充质干细胞移植到兔退变椎间盘髓核内的命运，并确定它们是否为细胞移植治疗退变的一种合适的选择。虽然骨髓间充质干细胞已被建议作为移植治疗腰椎间盘退变的候选供体细胞，但对其移植后的分化还没有充分的研究。将绿色荧光蛋白标记的自体骨髓间充质干细胞移植到成年兔体内。移植后48周连续计数核区移植的MSCs。免疫组织化学方法检测移植细胞的分化情况。采用二甲基亚甲基蓝比色法测定蛋白多糖含量，用逆转录聚合酶链式反应半定量测定I型和II型胶原、聚集素和VERSICAN的mRNA表达。移植后2周，细胞移植兔髓核内可见大量绿色荧光蛋白阳性细胞。他们的数量在48周内显著增加。部分GFP阳性细胞表达与细胞相关的基质分子，如II型胶原、硫酸角蛋白、硫酸软骨素、聚集素、髓核表型标志物、缺氧诱导因子1α、谷氨酰胺转运体1和基质金属蛋白酶2。移植前MSCs未见这些分子的显著表达。生化和基因表达分析显示，与未移植的椎间盘相比，总蛋白多糖含量和基质相关基因明显恢复。骨髓间充质干细胞移植到兔退变椎间盘后增殖分化为表达髓核细胞主要表型特征的细胞，提示这些细胞可能经历了部位依赖性的分化。还需要进一步的研究来评估它们的功能作用。
Study Design. An in vivo study to assess the differentiation status of mesenchymal stem cells (MSCs) transplanted to the nucleus pulposus of degenerative discs in a rabbit model.Objectives. To evaluate the fate of MSCs transplanted to the nucleus pulposus of degenerative discs in a rabbit and to determine whether they are a suitable alternative for cell transplantation therapy for disc degeneration.Summary of Background Data. Although MSCs have been proposed as candidate donor cells for transplantation to treat intervertebral disc degeneration, their differentiation after transplantation has not been adequately investigated.Methods. Autologous MSCs, labeled with green fluorescent protein, were transplanted into mature rabbits. Consecutive counts of transplanted MSCs in the nucleus area were performed for 48 weeks after transplantation. Differentiation of transplanted cells was determined by immunohistochemical analysis. The proteoglycan content of discs was measured quantitatively using a dimethylmethylene blue assay, and mRNA expression of Type I and II collagen, aggrecan and versican was measured semi-quantitatively using reverse transcription polymerase chain reaction.Results. Many cells that were positive for green fluorescent protein were observed in the nucleus pulposus of cell-transplanted rabbit discs 2 weeks after transplantation. Their number increased significantly by 48 weeks. Some GFP-positive cells were positive for cell-associated matrix molecules, such as Type II collagen, keratan sulfate, chondroitin sulfate, aggrecan, and the nucleus pulposus phenotypic markers, hypoxia inducible factor 1 alpha, glutamine transporter 1, and matrix metalloproteinase 2. MSCs did not show significant expression of these molecules before transplantation. Biochemical and gene expression analyses showed significant restoration of total proteoglycan content and matrix-related genes compared with nontransplanted discs.Conclusions. MSCs transplanted to degenerative discs in rabbits proliferated and differentiated into cells expressing some of the major phenotypic characteristics of nucleus pulposus cells, suggesting that these MSCs may have undergone site-dependent differentiation. Further studies are needed to evaluate their functional role.