Development of novel strategy for targeting of functional proteins into hasement membrance

生长因子与多种细胞外基质蛋白结合，包括热休克蛋白、胶原和纤维连接蛋白。然而，与LN亚型的相互作用仍不清楚。在这项研究中，我们用ELISA法检测了三种血管生成相关生长因子HGF、bFGF和VEGF与LN 1、2/4、5、8和10/11的相互作用。HGF优先与LN 10/11和LN 8结合，而肝素、低pH和肝素酶II处理则抑制结合。与293F细胞表达的LN 10的结合弱于与A549细胞表达的LN 10/11的结合。诱变研究表明，HGF结合部位可能位于LN10的短臂。此外，LN10/11结合的HGF可促进HMEC-1细胞的增殖。碱性成纤维细胞生长因子对LNS也表现出类似的结合偏好，VEGE与LNS的结合相对较弱。综上所述，富含血管基底膜的LN 10/11能够以不同的亲和力捕获血管生成相关生长因子HGF、bFGF和VEGF，促进细胞增殖。这些相互作用可能在不同的生理或病理过程中受到环境因素的调节，如硫酸肝素的修饰和pH的变化。

Growth factors bind to various ECM proteins including HSPG, collagen, and fibronectin. However, interaction with LN isoforms remains unknown. In this study, we examined the interaction of three angiogenesis-related growth factors, HGF, bFGF, and VEGF, with LN 1, 2/4, 5, 8, and 10/11 by ELISA. HGF bound preferentially to LN 10/11 and LN 8, and binding was inhibited by heparin, low pH, and heparitinase II treatment. Binding to the 293F cell-expressed LN 10 was weaker than that to LN 10/11 from A549 cells. Mutagenesis studies indicated that HGF-binding sites possibly reside in the short arm of LN 10. Moreover, LN 10/11-bound HGF promoted proliferation of HMEC-1 cells. bFGF also exhibited similar binding preference for LNs, and binding of VEGE to LNs is comparably weak. In conclusion, LN 10/11, rich in blood vessel basement membrane, could capture the angiogenesis-related growth factor such as HGF, bFGF and VEGF with different affinity to promote cell proliferation. These interactions were possibly regulated by such environment factors as heparan sulfate modification and pH change during different physiological or pathological processes.