Darling Eric M, Athanasiou Kyriacos A
Department of Bioengineering, Rice University, MS 142, P.O. Box 1892, Houston, TX 77251, USA.
J Orthop Res. 2005 Mar;23(2):425-32. doi: 10.1016/j.orthres.2004.08.008.
Articular chondrocytes are often expanded in vitro and then used to assist in healing articular cartilage defects. We investigated the extent of dedifferentiation in monolayer-passaged, zonal articular chondrocytes by using quantitative, real-time PCR. The relative gene expressions for collagen type I and II, aggrecan, and superficial zone protein were analyzed for relevant passage numbers (P0-P4) to determine how the expansion of chondrocytes affects the expression of cartilage extracellular matrix proteins. Results reveal that dramatic changes occur as early as first passage. Furthermore, these changes are shown to persist even when the expanded cells are encapsulated in 3D, alginate beads. Successful tissue engineering and autologous cell transplantation procedures rely heavily on having a cell source that expresses the chondrocytic phenotype. The results of this study suggest that major problems exist at the front-end of cartilage regeneration efforts.
关节软骨细胞通常在体外进行扩增，然后用于协助修复关节软骨缺损。我们通过定量实时聚合酶链反应研究了单层传代的不同区域关节软骨细胞的去分化程度。分析了I型和II型胶原蛋白、聚集蛋白聚糖和浅表区蛋白在相关传代数（P0 - P4）时的相对基因表达，以确定软骨细胞的扩增如何影响软骨细胞外基质蛋白的表达。结果显示，早在首次传代时就发生了显著变化。此外，即使将扩增后的细胞封装在三维藻酸盐珠中，这些变化仍会持续存在。成功的组织工程和自体细胞移植程序在很大程度上依赖于拥有表达软骨细胞表型的细胞来源。本研究结果表明，软骨再生努力的前端存在重大问题。
