A novel integrin α5β1 binding domain in module 4 of connective tissue growth factor (CCN2/CTGF) promotes adhesion and migration of activated pancreatic stellate cells
A novel integrin α5β1 binding domain in module 4 of connective tissue growth factor (CCN2/CTGF) promotes adhesion and migration of activated pancreatic stellate cells
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DOI：
10.1136/gut.2005.079178
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发表时间：
2006-06-01
期刊：
影响因子：
24.5
通讯作者：
Brigstock, D. R.
中科院分区：
文献类型：
--
作者：
Gao, R.;Brigstock, D. R.
背景：在胰腺纤维化和促结缔组织增生性胰腺肿瘤中，结缔组织生长因子（CCN2）表达上调。CCN2与胰腺星状细胞（PSC）上的整合素α(5)β(1)相互作用，刺激纤维生成、黏附、迁移和增殖。
目的：确定CCN2中与整合素α(5)β(1)相互作用以调节PSC功能的结构域。
方法：检测原代活化大鼠PSC对包含模块1 - 4（CCN2(1 - 4)）、模块3 - 4（CCN2(3 - 4)）、单独模块3（CCN2(3)）或单独模块4（CCN2(4)）的CCN2异构体的黏附情况。在乙二胺四乙酸（EDTA）、二价阳离子、抗整合素α(5)β(1)抗体、CCN2合成肽或肝素存在的情况下，或在用肝素酶、软骨素酶或氯酸钠预处理细胞后进行黏附研究。在无细胞系统中分析CCN2与整合素α(5)β(1)的结合。在抗整合素α(5)β(1)或肝素存在的情况下，评估CCN2(1 - 4)、CCN2(3 - 4)或CCN2(4)刺激PSC迁移的能力。
结果：CCN2(1 - 4)、CCN2(3 - 4)或CCN2(4)刺激PSC黏附，且这种黏附由Mg²⁺而非Ca²⁺支持。抗整合素α(5)β(1)抗体或用肝素酶或氯酸钠处理细胞可阻断CCN2(4)对PSC黏附或迁移的支持作用。在无细胞实验中证实了CCN2(4)与整合素α(5)β(1)之间的直接相互作用。模块4中的序列GVCTDGR介导了CCN2(4)与整合素α(5)β(1)之间的结合，以及CCN2(4)介导的PSC黏附和迁移。
结论：CCN2模块4中的GVCTDGR序列是一个新的整合素α(5)β(1)结合位点，对CCN2刺激PSC的功能至关重要，它代表了PSC介导的纤维生成的一个新的治疗靶点。
Background: Connective tissue growth factor (CCN2) is upregulated in pancreatic fibrosis and desmoplastic pancreatic tumours. CCN2 interacts with integrin alpha(5)beta(1) on pancreatic stellate cells (PSC) in which it stimulates fibrogenesis, adhesion, migration, and proliferation.Aim: To determine the structural domain(s) in CCN2 that interact with integrin alpha(5)beta(1) to regulation PSC functions.Methods: Primary activated rat PSC were tested for their adherence to isoforms of CCN2 comprising modules 1-4 (CCN2(1-4)), modules 3-4 (CCN2(3-4)), module 3 alone (CCN2(3)), or module 4 alone (CCN2(4)). Adhesion studies were performed in the presence of EDTA, divalent cations, anti-integrin alpha(5)beta(1) antibodies, CCN2 synthetic peptides, or heparin, or after pretreatment of the cells with heparinase, chondroitinase, or sodium chlorate. CCN2 integrin alpha(5)beta(1) binding was analysed in cell free systems. The ability of CCN2(1-4), CCN2(3-4), or CCN2(4) to stimulate PSC migration was evaluated in the presence of anti-integrin alpha(5)beta(1) or heparin.Results: PSC adhesion was stimulated by CCN2(1-4), CCN2(3-4), or CCN2(4) and supported by Mg2+ but not Ca2+. CCN2(4) supported PSC adhesion or migration were blocked by anti-integrin alpha(5)beta(1) antibodies or by treatment of cells with heparinase or sodium chlorate. A direct interaction between CCN2(4) and integrin alpha(5)beta(1) was demonstrated in cell free assays. The sequence GVCTDGR in module 4 mediated the binding between CCN2(4) and integrin alpha(5)beta(1) as well as CCN2(4) mediated PSC adhesion and migration.Conclusions: A GVCTDGR sequence in module 4 of CCN2 is a novel integrin alpha(5)beta(1) binding site that is essential for CCN2 stimulated functions in PSC and which represents a new therapeutic target in PSC mediated fibrogenesis.