Chen C W, Tsai Y H, Deng W P, Shih S N, Fang C L, Burch J G, Chen W H, Lai W F
Institute of Medical Sciences, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan.
J Orthop Res. 2005 Mar;23(2):446-53. doi: 10.1016/j.orthres.2004.09.002.
Chondrogenic differentiation by mesenchymal progenitor cells (MPCs) is associated with cytokines such as transforming growth factor-beta 1 (TGF-beta1) and dexamethasone. Extracellular matrix (ECM) also regulates the differentiation by MPCs. To define whether ECM plays a functional role in regulation of the chondrogenic differentiation by MPCs, an in vitro model was used. That model exposed to dexamethasone, recombinant human TGF-beta1(rhTGF-beta1) and collagens. The results showed that MPCs incorporated with dexamethasone and rhTGF-beta1 increased proliferation and expression of glycosaminoglycan (GAG) after 14 days. Type II collagen enhanced the GAG synthesis, but did not increase alkaline phosphatase (ALP) activity. When adding dexamethasone and rhTGF-beta1 MPCs increased mRNA expression of Sox9. Incorporation with type II collagen, dexamethasone and rhTGF-beta1, MPCs induced mRNA expression of aggrecan and enhanced levels of type II collagen, and Sox9 mRNA. In contrast, incorporation with type I collagen, dexamethasone and rhTGF-beta1 MPCs reduced levels of aggrecan, and Sox9 mRNA, and showed no type II collagen mRNA. Altogether, these results indicate that type I and II collagen, in addition to the cytokine effect, may play a functional role in regulating of chondrogenic differentiation by MPCs.
间充质祖细胞（MPCs）的软骨形成分化与诸如转化生长因子-β1（TGF-β1）和地塞米松等细胞因子相关。细胞外基质（ECM）也调节MPCs的分化。为了确定ECM在MPCs软骨形成分化调节中是否发挥功能作用，使用了一种体外模型。该模型暴露于地塞米松、重组人TGF-β1（rhTGF-β1）和胶原蛋白。结果显示，与地塞米松和rhTGF-β1结合的MPCs在14天后增殖增加且糖胺聚糖（GAG）表达增强。II型胶原增强了GAG合成，但未增加碱性磷酸酶（ALP）活性。当添加地塞米松和rhTGF-β1时，MPCs的Sox9 mRNA表达增加。与II型胶原、地塞米松和rhTGF-β1结合，MPCs诱导了聚集蛋白聚糖的mRNA表达并增强了II型胶原和Sox9 mRNA的水平。相反，与I型胶原、地塞米松和rhTGF-β1结合的MPCs降低了聚集蛋白聚糖和Sox9 mRNA的水平，且未显示II型胶原mRNA。总之，这些结果表明，除细胞因子作用外，I型和II型胶原可能在调节MPCs软骨形成分化中发挥功能作用。
