N-Sulfation of Heparan Sulfate Regulates Early Branching Events in the Developing Mammary Gland
N-Sulfation of Heparan Sulfate Regulates Early Branching Events in the Developing Mammary Gland
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DOI：
10.1074/jbc.m112.423327
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发表时间：
2012-12-07
影响因子：
4.8
通讯作者：
Nigam, Sanjay K.
中科院分区：
文献类型：
--
作者：
Bush, Kevin T.;Crawford, Brett E.;Nigam, Sanjay K.
分支形态发生是上皮器官（例如乳腺、肾、肺、唾液腺、前列腺、胰腺）发育的基本过程，部分依赖于硫酸乙酰肝素蛋白聚糖的硫酸化。适当的硫酸化由生物合成酶介导，包括外生骨素-2（Ext 2）、N-脱乙酰基酶/N-磺基转移酶和硫酸乙酰肝素O-磺基转移酶。最近的条件敲除表明，尽管初级分支依赖于硫酸乙酰肝素，但其它阶段依赖于N-硫酸盐和/或2-O硫酸化的选择性添加（Crawford，B. E、加纳岛B.，Bishop，J.R.，Zhang、黑腹叶蝉D.是的，Bush，K. T.，Nigam，S. K.，和Esko，J.D.（2010）PLoS One 5，e10691; Garner，O. B.，Bush，K. T.，Nigam，S. K.，Yamaguchi，Y.，徐，D.，Esko，J.D.，和Nigam，S. K.（2011）Dev. 355，394-403）。在这里，我们分析了删除Ndst 2和Ndst 1的效果。而Ndst 1的缺失对一级或二级分支没有重大影响，Ndst 2的缺失似乎导致分支的轻度增加。当这两个基因被删除，导管的增长是非常减少（可能是由于可变的Cre重组酶活性），但过剩的分支结构是明显的，无论腺体生长或出生后年龄的程度。“超支化”是一种不寻常的表型。对N-硫酸化和生长因子结合的影响进行了生物化学证实。结果表明，N-硫酸化或需要N-硫酸化的因子调节发育中的乳腺中的初级和次级分支事件。与以前的工作一起，数据表明，不同阶段的导管分支和小叶肺泡形成的硫酸乙酰肝素生物合成酶在适当的生长因子的情况下，由不同的集合进行调节。
Branching morphogenesis, a fundamental process in the development of epithelial organs (e.g. breast, kidney, lung, salivary gland, prostate, pancreas), is in part dependent on sulfation of heparan sulfate proteoglycans. Proper sulfation is mediated by biosynthetic enzymes, including exostosin-2 (Ext2), N-deacetylase/N-sulfotransferases and heparan sulfate O-sulfotransferases. Recent conditional knockouts indicate that whereas primary branching is dependent on heparan sulfate, other stages are dependent upon selective addition of N-sulfate and/or 2-O sulfation (Crawford, B. E., Garner, O. B., Bishop, J. R., Zhang, D. Y., Bush, K. T., Nigam, S. K., and Esko, J. D. (2010) PLoS One 5, e10691; Garner, O. B., Bush, K. T., Nigam, S. K., Yamaguchi, Y., Xu, D., Esko, J. D., and Nigam, S. K. (2011) Dev. Biol. 355, 394-403). Here, we analyzed the effect of deleting both Ndst2 and Ndst1. Whereas deletion of Ndst1 has no major effect on primary or secondary branching, deletion of Ndst2 appears to result in a mild increase in branching. When both genes were deleted, ductal growth was variably diminished (likely due to variable Cre-recombinase activity), but an overabundance of branched structures was evident irrespective of the extent of gland growth or postnatal age. "Hyperbranching" is an unusual phenotype. The effects on N-sulfation and growth factor binding were confirmed biochemically. The results indicate that N-sulfation or a factor requiring N-sulfation regulates primary and secondary branching events in the developing mammary gland. Together with previous work, the data indicate that different stages of ductal branching and lobuloalveolar formation are regulated by distinct sets of heparan sulfate biosynthetic enzymes in an appropriate growth factor context.