TGF-β2体外诱导骨髓间充质干细胞表达软骨细胞表型的观察

目的：观察骨髓间充质干细胞（MSCs）在TGF-β2诱导下向软骨细胞表型转化的能力，探讨其作为软骨组织工程种子细胞的可能性。方法：抽取兔髂骨骨髓液3-4ml，进行原代和传代培养，传代后实验组以高糖DMEM无血清特定培养液诱导f含TGF-β2 10ng／ml、地塞米松10^-7M、维生素C50μmol／L），对照组以高糖DMEM无血清培养液培养，相差显微镜下观察细胞形态变化，免疫组织化学染色检测软骨特异性Ⅱ型胶原表达。结果：诱导后细胞体外扩增能力显著降低，细胞形态由成纤维样梭形向多角形、多边形或类圆形转变，诱导21天后细胞形态变化最为显著，Ⅱ型胶原免疫组化染色深而均匀。结论：TGF-β2可有效诱导MSCs向软骨细胞表型转化，分泌软骨细胞特异性基质，有可能成为软骨组织工程较理想的种子细胞来源。

Expression of Chondrocyte Phaenotype Under the Induction of Bone Marrow Stem Cells in Vitro

Objective： To investigate the feasibility of chondrogenic phenotype differentiation of rabbit bone marrow stem cells （MSCs） under the induction of transforming growth factor-β2 as seeding cells in cartilage tissue engineering. Methods： About 3-4ml of bone marrow were aspirated from bilateral femoral, and then primary and subcultures of MSCs were carried out. In the experimental group, the subcultures of MSCs were cultured in serumfree chondroinductive medium containing TGF-β2, dexamethasone and ascorbic acid. In the control group, the cells were cultured in serum-free medium. The growth of the cultured MSCs was observed by phase-microscope. Immunohistochemical staining was eapplied to detect the expression of collagen type Ⅱ. Results： The cells of the experimental group changed from a spindle-like fibroblastic appearance to a polygonal shape, the capability of proliferation was down markedly. Immunohistochemical staining of collagen Ⅱ was positive for the pass age, especially in the 21st days. Conclusion： Under the induction of TGF-β2, MSCs could differentiate into chondrogenic phenotype and secrete specificity matrix of cartilage in vitro. MSCs can likely be served as optimal autogenous cell source for cartilage tissue engineering.