Soluble Endoglin Specifically Binds Bone Morphogenetic Proteins 9 and 10 via Its Orphan Domain, Inhibits Blood Vessel Formation, and Suppresses Tumor Growth
Soluble Endoglin Specifically Binds Bone Morphogenetic Proteins 9 and 10 via Its Orphan Domain, Inhibits Blood Vessel Formation, and Suppresses Tumor Growth
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DOI：
10.1074/jbc.m111.260133
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发表时间：
2011-08-26
影响因子：
4.8
通讯作者：
Grinberg, Asya V.
中科院分区：
文献类型：
--
作者：
Castonguay, Roselyne;Werner, Eric D.;Grinberg, Asya V.
Endoglin（CD105）是转化生长因子超家族的跨膜蛋白，在血管生成中起着至关重要的作用。内尾突变导致称为遗传出血性毛细血管扩张（HHT1）的血管缺陷。建议内尾的可溶形式有助于先兆子痫的发病机理。为了进一步了解其功能，我们克隆，表达，纯化和表征了小鼠和人内og的细胞外结构域（ECD），融合到免疫球蛋白FC结构域。我们发现，在表面等离子体共振（BIACORE）和基于细胞的测定中，小鼠和人内od型ECD ECD-FC与骨形态发生蛋白9和10（BMP9和BMP10）具有高亲和力。我们通过研究了它们对蛋白质的选择性和生物学活性的贡献，对内元的不同领域进行了函数映射分析。 BMP9/BMP10结合位点位于由氨基酸序列26-359组成的人内o的孤儿域。我们确定了内o和II型受体与BMP9上重叠位点结合的。在体内鸡绒毛膜膜膜测定中，小鼠和被截短的人内og骨ECD-FC都显着降低了VEGF诱导的血管形成。最后，鼠内og鼠ECD-FC充当了一种抗血管生成因子，可减少体内血管造影剂中VEGF/FGF诱导的血管生成的血管发芽，并减少结肠26小鼠肿瘤模型中的肿瘤负担。我们的发现共同表明可溶性内og eCD在调节血管生成方面的重要作用，并突出内og胶-FC作为潜在的抗血管生成治疗剂的功效。
Endoglin (CD105), a transmembrane protein of the transforming growth factor beta superfamily, plays a crucial role in angiogenesis. Mutations in endoglin result in the vascular defect known as hereditary hemorrhagic telangiectasia (HHT1). The soluble form of endoglin was suggested to contribute to the pathogenesis of preeclampsia. To obtain further insight into its function, we cloned, expressed, purified, and characterized the extracellular domain (ECD) of mouse and human endoglin fused to an immunoglobulin Fc domain. We found that mouse and human endoglin ECD-Fc bound directly, specifically, and with high affinity to bone morphogenetic proteins 9 and 10 (BMP9 and BMP10) in surface plasmon resonance (Biacore) and cell-based assays. We performed a function mapping analysis of the different domains of endoglin by examining their contributions to the selectivity and biological activity of the protein. The BMP9/BMP10 binding site was localized to the orphan domain of human endoglin composed of the amino acid sequence 26-359. We established that endoglin and type II receptors bind to overlapping sites on BMP9. In the in vivo chick chorioallantoic membrane assay, the mouse and the truncated human endoglin ECD-Fc both significantly reduced VEGF-induced vessel formation. Finally, murine endoglin ECD-Fc acted as an anti-angiogenic factor that decreased blood vessel sprouting in VEGF/FGF-induced angiogenesis in in vivo angioreactors and reduced the tumor burden in the colon-26 mouse tumor model. Together our findings indicate an important role of soluble endoglin ECD in the regulation of angiogenesis and highlight efficacy of endoglin-Fc as a potential anti-angiogenesis therapeutic agent.