Institut National de la Santé et de la Recherche Médicale, UMRS 791, Université de Nantes, Laboratoire d'Ingénierie Ostéo-Articulaire et Dentaire, Group STEP Skeletal tissue Engineering and Physiopathology, Faculté de chirurgie dentaire, Nantes Cedex 1, France.
Cell Transplant. 2011;20(10):1575-88. doi: 10.3727/096368910X557191. Epub 2011 Feb 3.
Articular cartilage is an avascular tissue composed of chondrocytes, a unique cell type responsible for abundant matrix synthesis and maintenance. When damaged, it never heals spontaneously under physiological circumstances. Therefore, the delivery of mesenchymal stem cells using hydrogel has been considered for cartilage repair. This study aims at investigating the influence of in vitro chondrogenic differentiation of human adipose tissue-derived stem cells (hATSCs) on in vivo cartilage formation when associated with a cellulose-based self-setting hydrogel (Si-HPMC). hATSCs were characterized for their proliferation, surface marker expression, and multipotency. The in vitro chondrogenic potential of hATSCs cultured within Si-HPMC in control or chondrogenic medium was evaluated by measuring COL2A1, ACAN, SOX9, and COMP expression by real-time PCR. Alcian blue and type II collagen staining were also performed. To determine whether in vitro chondrogenically differentiated hATSCs may give rise to cartilage in vivo, cells differentiated as a monolayer or in pellets were finally associated with Si-HPMC and implanted subcutaneously into nude mice. Cartilage formation was assessed histologically by alcian blue and type II collagen staining. Our data demonstrate that hATSCs exhibited proliferation and self-renewal. hATSCs also expressed typical stem cell surface markers and were able to differentiate towards the adipogenic, osteogenic, and chondrogenic lineages. Real-time PCR and histological analysis indicated that Si-HPMC enabled chondrogenic differentiation of hATSCs in inductive medium, as demonstrated by increased expression of chondrogenic markers. In addition, histological analysis of implants showed that chondrogenically differentiated hATSCs (monolayers or pellets) have the ability to form cartilaginous tissue, as indicated by the presence of sulphated glycosaminoglycans and type II collagen. This study therefore suggests that an in vitro induction of hATSCs in 2D was sufficient to obtain cartilaginous tissue formation in vivo. Si-HPMC associated with autologous hATSCs could thus be a significant tool for regenerative medicine in the context of cartilage damage.
关节软骨是一种无血管组织，由软骨细胞组成，软骨细胞是一种独特的细胞类型，负责大量基质的合成和维持。当受到损伤时，在生理条件下它永远不会自发愈合。因此，使用水凝胶输送间充质干细胞已被考虑用于软骨修复。本研究旨在研究人脂肪组织源性干细胞（hATSCs）在体外向软骨分化对与纤维素基自凝固水凝胶（Si-HPMC）相关的体内软骨形成的影响。研究对 hATSCs 的增殖、表面标志物表达和多能性进行了特征描述。通过实时 PCR 测量 COL2A1、ACAN、SOX9 和 COMP 的表达，评估了在对照或软骨形成培养基中培养于 Si-HPMC 内的 hATSCs 的体外软骨形成潜能。还进行了阿尔新蓝和 II 型胶原染色。为了确定体外软骨分化的 hATSCs 是否能在体内产生软骨，最终将分化为单层或微球的细胞与 Si-HPMC 结合并植入裸鼠皮下。通过阿尔新蓝和 II 型胶原染色对软骨形成进行组织学评估。我们的数据表明，hATSCs 表现出增殖和自我更新。hATSCs 还表达了典型的干细胞表面标志物，并能够向脂肪形成、成骨和软骨形成谱系分化。实时 PCR 和组织学分析表明，Si-HPMC 能够在诱导培养基中诱导 hATSCs 向软骨分化，表现为软骨形成标志物的表达增加。此外，植入物的组织学分析表明，软骨分化的 hATSCs（单层或微球）具有形成软骨组织的能力，这表明存在硫酸化糖胺聚糖和 II 型胶原。因此，本研究表明，在 2D 中体外诱导 hATSCs 足以在体内获得软骨组织形成。与自体 hATSCs 相关的 Si-HPMC 可能是软骨损伤再生医学的重要工具。
