02021nas a2200109   4500008004500000245004500045210004300090260003700133490002000170520168300190856003801873       1997                        Engldsh  00aFunctional Analysis of VEGF-B and VEGF-C0 aFunctional Analysis of VEGFB and VEGFC  aHelsinkibUniveristy of Helsinki0 vMaster's Thesis3 aVascular endothelial growth factor (VEGF) is an important regulator of endothelial cell proliferation and migration dur-
ing embryonic vasculogenesis and angiogenesis as well as in pathological angiogenesis. The recently cloned new factors
structurally homologous to VEGF were designated as VEGF-B/VRF and VEGF-C/VRP. The receptor for VEGF-B is
unknown. VEGF-C is the ligand for FLT4, a receptor tyrosine kinase whose expression becomes restricted largely to
lymphatic endothelia during development and that is related to VEGF receptors FLT1 and KDR.
In this study keratin 14-promoter-directed VEGF-C overexpression in the basal epidermis of transgenic mice was capa-
ble of promoting an abundant growth of extensive lymphatic-like vessel structures in the dermis, including large vessel
lacunae resembling in their histopathology the human condition known as lymphangioma. Thus, VEGF-C appears to
induce selective angiogenesis of the lymphatic vessels in vivo. In contrast, preliminary data on mice, which overexpress
VEGF-B under the same promoter, does not yet allow us draw any conclusions about its possible biological function.
Recombinant biologically active human VEGF-C was produced using the baculovirus system. Unpurified and purified
VEGF-C were used to confirm the interaction of VEGF-C with KDR, a fact recently missed by others. The recombinant
protein is going to be used in a large number of future experiments. The production of VEGF-B seems to be intrinsically
difficult in non-mammalian cells. Although quantitatively satisfying results could not be obtained yet, the purified
growth factor will be used in experiments to identify its receptor.  uhttp://urn.fi/URN:NBN:fi-fe977347