On the Roles and Regulation of Chondroitin Sulfate and Heparan Sulfate in Zebrafish Pharyngeal Cartilage Morphogenesis
On the Roles and Regulation of Chondroitin Sulfate and Heparan Sulfate in Zebrafish Pharyngeal Cartilage Morphogenesis
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DOI：
10.1074/jbc.m112.401646
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发表时间：
2012-09-28
影响因子：
4.8
通讯作者：
Ledin, Johan
中科院分区：
文献类型：
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作者：
Holmborn, Katarina;Habicher, Judith;Ledin, Johan
本研究探讨了硫酸乙酰肝素（HS）蛋白聚糖和硫酸软骨素（CS）蛋白聚糖在斑马鱼咽软骨结构发育中的作用。对uxs1和b3gat3突变体进行了分析，由于常见蛋白聚糖连接四糖形成缺陷，预计这两种突变体的HS和CS生物合成均受损；同时也分析了ext2和extl3突变体，预计它们的HS聚合存在缺陷。值得注意的是，各突变株对HS和CS生物合成的影响与之前的假设不同。在uxs1和b3gat3突变幼虫中，CS的生物合成几乎完全消失，而这些突变体仍能够合成对照幼虫所产生HS的50%。另一方面，extl3和ext2突变体被证明合成的高硫酸化HS量减少。此外，extl3突变体产生的CS水平高于对照幼虫，而吗啉代介导的csgalnact1/csgalnact2抑制导致HS生物合成增加。因此，Extl3和Csgalnact1/Csgalnact2蛋白的平衡影响HS/CS比率。对单一突变株以及ext2;uxs1双突变体的咽软骨元件形态进行了表征。发现了HS和CS产生与表型之间的相关性，即HS生物合成受损会影响软骨细胞的嵌入，而CS生物合成受损会抑制软骨细胞周围细胞外基质的形成。
The present study addresses the roles of heparan sulfate (HS) proteoglycans and chondroitin sulfate (CS) proteoglycans in the development of zebrafish pharyngeal cartilage structures. uxs1 and b3gat3 mutants, predicted to have impaired biosynthesis of both HS and CS because of defective formation of the common proteoglycan linkage tetrasaccharide were analyzed along with ext2 and extl3 mutants, predicted to have defective HS polymerization. Notably, the effects on HS and CS biosynthesis in the respective mutant strains were shown to differ from what had been hypothesized. In uxs1 and b3gat3 mutant larvae, biosynthesis of CS was shown to be virtually abolished, whereas these mutants still were capable of synthesizing 50% of the HS produced in control larvae. extl3 and ext2 mutants on the other hand were shown to synthesize reduced amounts of hypersulfated HS. Further, extl3 mutants produced higher levels of CS than control larvae, whereas morpholino-mediated suppression of csgalnact1/csgalnact2 resulted in increased HS biosynthesis. Thus, the balance of the Extl3 and Csgalnact1/Csgalnact2 proteins influences the HS/CS ratio. A characterization of the pharyngeal cartilage element morphologies in the single mutant strains, as well as in ext2;uxs1 double mutants, was conducted. A correlation between HS and CS production and phenotypes was found, such that impaired HS biosynthesis was shown to affect chondrocyte intercalation, whereas impaired CS biosynthesis inhibited formation of the extracellular matrix surrounding chondrocytes.