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

生长因子结合各种ECM蛋白，包括HSPG、胶原和纤连蛋白。然而，与LN亚型的相互作用仍然未知。在这项研究中，我们研究了三个血管生成相关的生长因子，HGF，bFGF和VEGF，与LN 1，2/4，5，8，和10/11的相互作用，通过ELISA。HGF优先结合LN 10/11和LN 8，肝素、低pH和肝素酶II处理可抑制结合。与293 F细胞表达的LN 10的结合弱于与来自A549细胞的LN 10/11的结合。突变研究表明，HGF结合位点可能位于LN 10的短臂。此外，LN 10/11结合的HGF促进HMEC-1细胞的增殖。bFGF对LN也表现出类似的结合偏好，并且VEGE与LN的结合非常弱。结论：LN 10/11富含血管基底膜，能以不同的亲和力捕获HGF、bFGF和VEGF等血管生成相关生长因子，促进细胞增殖。这些相互作用可能受到硫酸乙酰肝素修饰和pH变化等环境因素的调节，在不同的生理或病理过程中。

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.