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Functional analyses of TRPS1 in bone morphogenesis

TRPS1在骨形态发生中的功能分析

基本信息

批准号：
14570199
负责人：
MURAGAKI Yasuteru
金额：
$ 2.3万
依托单位：
Wakayama Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14570199/
关键词：
TRPS1 knockout mouse cartilage cell proliferation apoptosis 軟骨分化 Traps1 細胞外マトリックス

项目摘要

Tricho-rhino-phalangeal syndromes (TRPSs) are human inherited skeletal disorders and its responsible gene, TRPS1, was cloned by positional cloning. TRPS1 is thought to be a transcriptional repressor with 9 zinc-finger domains including a GATA DNA binding domain and a C-terminus Ikaros-like zinc finger domain. To investigate the pathophysiological function of Trps1, we generated the Trps1-deficient mice by gene targeting. Homozygote mutant mice die soon after birth due to respiratory failure. The long bones in the limbs are shorter than in wild-type mice. However, the length of the epiphyseal cartilage is longer in Trps1-deficient mice as compared to wild-type mice. Histological examination of the mutant growth plate showed that the length of proliferation, prehypertrophic, and hyperti-ophic chondrocyte zones is extended and the shape of chondrocytes is abnormal. BrdU incorporation into chondrocytes was significantly decreased in mutant epiphyseal cartilage. Also, the number of apoptotic hypertrophic chondrocytes was dramatically decreased as detected by a TUNEL method. In in situ hybridization, the localization of Trps1 mRNA in E14.5 limbs has been found to be very much overlapped with that of Gdf5 mRNA. Since Gdf5-/-mice have joint fusion in the digit, we examined the phalangeal joints of Trps1-deficient mice. Interestingly, phalanges are still fused with interzone cells in E18.5 mutant mice, while the joint spaces are completely formed in wild-type mice. A TUNEL staining demonstrated that virtually no positive cells are detected in E15.5 mutant interzone, while some positive cells are seen in wild-type mice, suggesting that Trps1 is closely associated with apoptosis of interzone cells in phalangeal joint formation. Altogether, we concluded that Trps1 regulates proliferation and apoptosis of chondrocytes.

毛发-鼻-趾骨综合征（TRPSs）是一种人类遗传性骨骼疾病，其致病基因TRPS 1是通过定位克隆技术克隆到的。TRPS 1被认为是具有9个锌指结构域的转录抑制因子，包括加塔DNA结合结构域和C-末端Ikaros样锌指结构域。为了研究Trps 1的病理生理功能，我们通过基因打靶的方法制备了Trps 1缺陷小鼠。纯合子突变小鼠出生后不久就因呼吸衰竭而死亡。四肢的长骨比野生型小鼠短。然而，与野生型小鼠相比，Trps 1缺陷型小鼠的骺软骨长度更长。组织学检查显示，软骨细胞增殖带、前肥大带和肥大带长度延长，形态异常。BrdU掺入软骨细胞显着减少突变骺软骨。此外，凋亡的肥大软骨细胞的数量显着减少，通过TUNEL法检测。在原位杂交中，发现Trps 1 mRNA在E14.5肢体中的定位与Gdf 5 mRNA的定位非常重叠。由于Gdf 5-/-小鼠在趾中具有关节融合，我们检查了Trps 1缺陷小鼠的指关节。有趣的是，在E18.5突变小鼠中，趾骨仍然与区间细胞融合，而在野生型小鼠中，关节间隙完全形成。TUNEL染色结果显示，在E15.5突变体间区中几乎没有检测到阳性细胞，而在野生型小鼠中观察到一些阳性细胞，提示Trps 1与趾关节形成中间区细胞的凋亡密切相关。总之，我们得出结论，Trps 1调节软骨细胞的增殖和凋亡。