Chondrogenesis of bone marrow mesenchymal stem cells in co-culture system with chondrocyte

Abstract

Objective To explore the effect of osteoarthritis (OA) chondrocytes and normal chondrocytes on the chondrogenesis of bone marrow mesenchymal stem cells (BMSCs) in self designed co-culture system. Methods Rabbit BMSCs and chondrocytes were isolated and expanded in vitro. OA chondrocytes were harvested from the rabbit of established osteoarthritis model. We made a BMSCs-low melting agarose constructs, then put it onto the self-made 6 well plates lattice assembly for co-culture with chondrocytes. The groups were divided into Normal P0-BMSCs, Normal P3-BMSCs, OA PO-BMSCs, OA P3-BMSCs and BMSCs (control) group. At 3, 7, 14 day culture, cultured cells in all groups were collected for real-time PCR, glycosaminoglycan (GAG) content, cytoactive detection, and histological observation. Results Type Ⅱ collagen gene expression was up-regulated in group Normal PO-BMSCs, which showed 5.1-, 7.2-, 11.2-fold increase over that of control group at 3, 7, 14 days, respectively. Type Ⅰ, Ⅱ collagen and aggrecan gene expressions were not obviously up-regulated. In group OA P3-BMSCs, type Ⅰ collagen gene expression level lower than the control group in 3, 7, 14 day. In normal PO-BMSCs, GAG content showed 2.59-fold increase over that of the control group. GAG content of group OA PO-BMSCs and control group showed no significant differences.Others groups showed significant differences in comparison with the control group (P＜0.05). Alcian stain showed positive in all groups. The normal PO-BMSCs group showed the darkest blue-stained. Conclusion Rabbit normal PO chondrocytes and rabbit OA P0 chondrocytes significantly enhanced chondrogenic differentiation of rabbit BMSCs. The secreted morphogens of the rabbit normal P3 chondrocytes and rabbit OA P3 chondrocytes do not have a significant effect on chondrogenic differentiation of rabbit BMSCs. Key words: Bone marrow; Mesenchymal stem cells; Chondrocytes; Cell differentiation