M. Rahmanian et al., HYALURONAN OLIGOSACCHARIDES INDUCE TUBE FORMATION OF A BRAIN ENDOTHELIAL-CELL LINE IN-VITRO, Experimental cell research, 237(1), 1997, pp. 223-230
In remodeling tissues the formation of new blood vessels is an essenti
al process which is regulated by different factors. During such proces
ses an increase in hyaluronan synthesis and turnover is often seen and
recent observations have suggested that hyaluronan can both promote a
nd inhibit neovascularization depending on its molecular mass. In this
work we show that a brain capillary endothelial cell line forms tubes
in a collagen gel after stimulation by hyaluronan oligosaccharides. U
ltrastructural examination of the tubes by transmission electron micro
scopy revealed that the cord-like outgrowths consisted of 3-10 tightly
packed cells containing a continuous:lumen. The tube formation in res
ponse to hyaluronan oligosaccharide was not mediated by activation of
receptors for fibroblast growth factor. The endothelial cell line, whi
ch does not synthesize hyaluronan, exhibited specific hyaluronan-bindi
ng sites, with about 3000 hyaluronan molecules (M-r 3.85 x 10(6)) boun
d per cell at saturation and K-d was 0.05 x 10(-9) M. Furthermore, the
cell line was stained with mAb IVd4 that recognizes a novel class of
hyaluronan-binding proteins and mAb IM7 which recognizes CD44 molecule
s. (C) 1997 Academic Press.