Abstract:

BACKGROUND: Hyaluronic acid is the most important component of intra-articular synovial fluid and plays a very important role on the cell morphogenesis, but its effect on bone marrow mesenchymal stem cells (MSCs) in the repair of cartilage defects remains unclear.
OBJECTIVE: To investigate the role of intra-articular environment to the MSCs by studying the influence of exogenous hyaluronic acid on proliferation and chondrogenic differentiation of rabbit bone marrow MSCs.
METHODS: The rabbit MSCs were isolated and cultured in the method of whole bone marrow and adherent culture. The fourth passage of cells were used for the experiment. The experimental group cells were induced by hyaluronic acid solution, with transforming growth factor-β3 induced group served as a positive control. The negative control group was joined regular medium. The features of chondrocytes were identified by toluidine blue staining, immunohistochemistry and RT-PCR to detect the expression of collagen Ⅱ after 7, 14, 21 day’s induction respectively.
RESULTS AND CONCLUSION: After induced by hyaluronic acid, the speed of cell proliferation slowed down. The cell morphology changed from long spindle to polygonal, oval. The extracellular matrix showed metachromasia with toluidine blue and positive with type Ⅱ collagen immunohistochemical staining. RT-PCR detection also showed the expression of type Ⅱ collagen mRNA. All the above showed the characteristics of cartilage cell differentiation. But their expressions were weaker than the positive control group. The results indicated that the exogenous hyaluronic acid can induce the rabbit MSCs differentiate to chondrocytes. But its capacity is weaker than transforming growth factor-β3. Therefore, the intra-articular environment plays a positive role in promoting chondrogenic differentiation of MSCs and supported that hyaluronic acid could be used as a matrix for cartilage tissue engineering.