The Role of proteoglycans in chondrocyte differentiation of mesenchymal stem cells

1.我们评估了超声（US）对间充质干细胞（MSCs）向软骨细胞缠结软骨基质形成分化的影响。当用转化生长因子-β（TGF-β）处理在团块中培养的人MSC时，通过阿辛蓝染色和聚集蛋白聚糖免疫染色评估它们分化成软骨细胞，但未处理的细胞团块和仅用BMP-6处理的细胞团块没有。此外，当低强度US每天应用于TGF-β处理的细胞团20分钟时，软骨细胞分化增强。结论：1. TGF-β对MSCs向软骨细胞的分化具有重要作用，超声可促进MSCs向软骨细胞的分化.使用软骨形成/软骨细胞N1511细胞，我们评估了多功能蛋白聚糖/PG-M在软骨细胞分化中的作用。N1511细胞在早期表现出多功能蛋白聚糖的瞬时高表达，在晚期表现出聚集蛋白聚糖的瞬时高表达，这反映了它们在软骨细胞分化过程中的体内表达模式。当使用反义技术抑制多功能蛋白聚糖表达时，如通过实时RT-PCR评估的，以下聚集蛋白聚糖表达降低和延迟。这些结果表明，多功能蛋白聚糖在软骨细胞分化早期的瞬时表达正调控软骨细胞的分化.除了高瞬时表达外，多功能蛋白聚糖持续表达，特别是在关节软骨中。我们发现多功能蛋白聚糖与透明质酸和连接蛋白共定位。生化分析进一步证实了多功能蛋白聚糖聚集体的存在。这些结果表明，存在两种蛋白多糖聚集体，这可能发挥不同的作用。

1. We evaluated the effects of ultrasound (US) on differentiation of mesenchymal stem cells (MSCs) toward chondrocyte snarl cartilage matrix formation. When human MSCs cultured in the pellets were treated with transforming growth factor-beta (TGF-b), they differentiated into chondrocytes as assessed by alcian blue staining and immunostaining for aggrecan, but non-treated cell pellets and cell pellets treated with BMP-6 alone did not. Furthermore, when low-intensity US was applied for 20 min everyday to the TGF-beta-treated cell pellets, chondrocyte differentiation was enhanced. These results suggest that TGF-b is essential for chondrocyte differentiation of MSCs in pellets and US enhances the differentiation.2. Using chondrogenic/chondrocytic N1511 cells, we evaluated the role of versican/PG-M in chondrocyet differentiation. N1511 cells exhibited transient high expression of versican at an early stage and that of aggrecan at a late stage, which reflects their in vivo expression patterns during chondrocyte differentiation. When versican expression was inhibited using an antisense technology, the following aggrecan expression was decreased and delayed, as assessed by realtime RT-PCR. These results suggest that transient versican expression at the early stage positively regulate chondrocyte differentiaion.3. In addition to high transient expression, versican is continuously expressed, especially in the articular cartilage. We found that versican is colocalized with both hyaluronan and link protein there. Biochemical analysis further confirmed the presence of versican aggregate. These results suggest the presence of tow proteoglycan aggregates, which may play distinct roles.