Syndecan-1-Induced ECM Fiber Alignment Requires Integrin αvβ3 and Syndecan-1 Ectodomain and Heparan Sulfate Chains.
Syndecan-1-Induced ECM Fiber Alignment Requires Integrin αvβ3 and Syndecan-1 Ectodomain and Heparan Sulfate Chains.
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DOI：
10.1371/journal.pone.0150132
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Friedl A
中科院分区：
文献类型：
--
作者：
Yang N;Friedl A
细胞表面蛋白聚糖syndecan-1（Sdc 1）的表达经常诱导浸润性乳腺癌的间质成纤维细胞。我们最近已经确定了间质Sdc 1表达和细胞外基质（ECM）纤维排列之间的相关性，在体外和体内。来自Sdc 1阳性的人乳腺成纤维细胞（HMF）的ECM显示出对齐的纤维结构，这与Sdc 1阴性的HMF产生的ECM中更随机的纤维排列形成鲜明对比。我们进一步证明，对齐的纤维结构促进乳腺癌细胞的定向迁移和侵袭。为了破译形成对齐的、允许入侵的ECM的分子机制，将一系列Sdc 1突变体引入HMF。我们发现Sdc 1的胞外域和硫酸乙酰肝素链都是Sdc 1在调节ECM排列中的完全活性所必需的，而跨膜和胞质结构域则是必需的。sdc 1通过其胞外域调节几种整合素的活性。整合素是富含纤连蛋白的ECM组装的关键参与者。此外，整联蛋白能够调节细胞形态，并且细胞形状和取向可能影响ECM结构。因此，我们研究了整合素在Sdc 1介导的ECM纤维排列中的作用。当在允许ECM产生的条件下以过度融合状态培养时，Sdc 1过表达的HMF获得增强的纺锤形形态，这通过siRNA介导的β3整合素表达沉默而部分逆转。此外，通过功能阻断抗体或β3敲低抑制αvβ3整联蛋白活性在很大程度上消除了对齐的ECM纤维结构，从而消除了Sdc 1诱导的ECM的侵袭许可特性。结果表明，Sdc 1可能通过αvβ3整合素调节ECM产生过程中的纤连蛋白原纤维形成和/或改变细胞形态，从而介导ECM纤维排列。了解ECM组织的机制可能会导致乳腺癌的新型基质靶向治疗的发展，旨在将侵入许可的微环境转换为侵入限制的微环境。
Expression of the cell surface proteoglycan syndecan-1 (Sdc1) is frequently induced in stromal fibroblasts of invasive breast carcinomas. We have recently identified a correlation between stromal Sdc1 expression and extracellular matrix (ECM) fiber alignment, both in vitro and in vivo. ECMs derived from Sdc1-positive human mammary fibroblasts (HMF) showed an aligned fiber architecture, which contrasted markedly with the more random fiber arrangement in the ECM produced by Sdc1-negative HMFs. We further demonstrated that aligned fiber architecture promotes the directional migration and invasion of breast carcinoma cells. To decipher the molecular mechanisms governing the formation of an aligned, invasion-permissive ECM, a series of Sdc1 mutants was introduced into HMF. We found that both the ectodomain and heparan sulfate chains of Sdc1 were required for full activity of Sdc1 in regulating ECM alignment, while transmembrane and cytoplasmic domains were dispensable. Sdc1 regulates the activities of several integrins via its ectodomain. Integrins are key players in the assembly of fibronectin-rich ECM. In addition, integrins are capable of regulating cell morphology and cell shape and orientation may affect ECM architecture. Therefore, we investigated the role of integrins in Sdc1-mediated ECM fiber alignment. Sdc1-overexpressing HMF gained an enhanced spindle-shaped morphology when cultured in an overconfluent state under conditions permissive for ECM production, which was partially reversed by siRNA-mediated silencing of β3 integrin expression. Moreover, suppression of αvβ3 integrin activity by a function-blocking antibody or β3 knockdown largely abolished the aligned ECM fiber architecture and consequently the invasion-permissive properties of the ECM induced by Sdc1. The results suggest that Sdc1 may modulate fibronectin fibrillogenesis and/or alter cell morphology during ECM production through αvβ3 integrin, thereby mediating ECM fiber alignment. Understanding the mechanisms governing ECM organization may lead to the development of novel stroma-targeted therapy for breast cancer, aiming at converting an invasion-permissive to an invasion-restrictive microenvironment.