Department of Orthopaedic Surgery, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu-city, Mie 514-8507, Japan.
Biochem Biophys Res Commun. 2010 Jan 1;391(1):1116-21. doi: 10.1016/j.bbrc.2009.12.034. Epub 2009 Dec 11.
Fibulin-3 is a member of the fibulin family that has been newly recognized as extracellular matrix proteins. We assessed the effects of fibulin-3 overexpression on chondrocyte differentiation using the clonal murine cell line ATDC5. The ATDC5-FBLN3 stably expressing fibulin-3 protein was spindle-shaped cell compared to the ATDC5-mock with plump cell. The cell growth in the ATDC5-FBLN3 was accelerated in comparison to that in the ATDC5-mock. The ATDC5-FBLN3 was not stained by Alcian blue, nor was there any cartilage aggregate formed after the induction of chondrogenic differentiation. The expression of type II collagen, aggrecan, and type X collagen was completely suppressed in ATDC5-FBLN3 even after the induction of differentiation. The overexpression of fibulin-3 reduced the expression of Sox5 and Sox6, while it maintained the expression of Sox9. These findings suggest that fibulin-3 may play an important role as a negative regulator of chondrocyte differentiation.
纤连蛋白 3 是纤连蛋白家族的一员，它最近被新认定为细胞外基质蛋白。我们使用克隆鼠细胞系 ATDC5 评估了纤连蛋白 3 过表达对软骨细胞分化的影响。与丰满细胞的 ATDC5- mock 相比，稳定表达纤连蛋白 3 蛋白的 ATDC5-FBLN3 呈梭形细胞。与 ATDC5- mock 相比，ATDC5-FBLN3 的细胞生长加速。ATDC5-FBLN3 未被阿利新蓝染色，在诱导软骨分化后也未形成任何软骨聚集。即使在诱导分化后，ATDC5-FBLN3 中 II 型胶原、聚集蛋白聚糖和 X 型胶原的表达也完全受到抑制。纤连蛋白 3 的过表达降低了 Sox5 和 Sox6 的表达，而 Sox9 的表达得到维持。这些发现表明纤连蛋白 3 可能作为软骨细胞分化的负调节剂发挥重要作用。
