Ganss Bernhard, Kobayashi Hiroaki
CIHR Group in Matrix Dynamics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
J Bone Miner Res. 2002 Dec;17(12):2151-60. doi: 10.1359/jbmr.2002.17.12.2151.
The differentiation of many mesenchyme-derived cells, including cells that form bone and cartilage, is regulated at the level of gene transcription, but many of the factors involved in this regulation remain to be identified. In this study, a modified RNA fingerprinting technique was used to identify the KRAB domain zinc finger transcription factor Zfp60 as a candidate regulator of cell differentiation in mouse calvaria primary cultures. The highest expression of Zfp60 mRNA in vivo was found between embryonic day 11 (E11) and E15 during mouse embryonic development, coinciding with stages of active organ formation. The expression of Zfp60 mRNA and protein was analyzed further in mouse embryos during skeletal development. The most prominent expression was found in prehypertrophic chondrocytes, where it coincides with the expression of key regulators of chondrocyte maturation, Indian hedgehog (Ihh), and the parathyroid hormone-related peptide (PTHrP) receptor. Zfp60 mRNA was also found transiently expressed during chondrogenesis of C1 cells in vitro, preceding collagen type X expression and cellular hypertrophy. Overexpression of Zfp60 inhibited cartilage differentiation in the chondrogenic ATDC5 cell line. These results suggest a role for Zfp60 as a negative regulator of gene transcription, specifically during the development and/or differentiation of chondrocytes.
包括形成骨骼和软骨的细胞在内的许多间充质来源细胞的分化，在基因转录水平受到调控，但参与这种调控的许多因子仍有待确定。在本研究中，一种改良的RNA指纹技术被用于鉴定KRAB结构域锌指转录因子Zfp60，作为小鼠颅骨原代培养物中细胞分化的候选调节因子。在小鼠胚胎发育期间，体内Zfp60 mRNA的最高表达在胚胎第11天（E11）至E15之间被发现，这与活跃的器官形成阶段一致。在骨骼发育过程中，对小鼠胚胎中Zfp60 mRNA和蛋白质的表达进行了进一步分析。最显著的表达出现在前肥大软骨细胞中，在此处它与软骨细胞成熟的关键调节因子印度刺猬因子（Ihh）和甲状旁腺激素相关肽（PTHrP）受体的表达一致。在体外C1细胞软骨形成过程中，也发现Zfp60 mRNA短暂表达，先于X型胶原表达和细胞肥大。Zfp60的过表达抑制了软骨形成性ATDC5细胞系中的软骨分化。这些结果表明Zfp60作为基因转录的负调节因子发挥作用，特别是在软骨细胞的发育和/或分化过程中。
