Neurotrophic role of VEGF in the olfactory epithelium Bufo arenarum

POZZI AG; JUNGBLUT LD; YOVANOVICH CA; HEER T; PAZ DA

Pinamar, Buenos Aires

Congreso; 10th Congress of Panamerican Association for Biochemistry and Molecular Biology. 20th Annual Meeting Argentine Society for Neurochemistry; 2005

Sociedad Argentina de Investigaciones en Bioquimica y Biología Molecular. Sociedad Argentina de Neuroquimica

Recently, Vascular Endothelial Growth Factor (VEGF) has been shown to be a neurotrophic factor in the peripheral and central nervous system. Co-expression of VEGF and its receptor Flk-1 in neurons was noted. In the Olfactory epithelium, neurons are replaced continuously by means of apoptosis, proliferation and differentiation processes. We have observed the presence of VEGF and Flk-1 in the olfactory system during development of the toad Bufo arenarum. VEGF co localizes with Flk-1 in mature neurons, however Flk-1 was also observed in the basal cells (stem) layer. Because VEGF promotes neuronal proliferation in other system, we examined the possibility that it also stimulates neuronal proliferation in the olfactory epithelium during larval development. Intracerebral administration of VEGF (2ng/µl) increased immunostaining of Flk-1 and BDNF. These increments were confirmed by Western blot. On the other hand, VEGF injection stimulated PCNA immunostaining and BrdU incorporation into immature basal cell and scattered cells in other layers of the epithelium. In addition, the treatment with green tea (0.5%), and VEGF inhibitor, caused and increase of the activated-caspase 3 immunostaining (apoptotic marker). These evidences suggest that VEGF play an important role as a neurotrophic factor in the development of the olfactory epithelium in Bufo arenarum.