FGF-2 overexpression opposes the beta amyloid toxic injuries to the vascular endothelium.

ABSTRACT

Recent evidences suggest that Abeta peptides modulate endothelial cell (EC) functions. At low concentrations, Abeta1-40 enhances the pro-angiogenic activity of FGF-2, whereas deposition of excess Abeta causes EC dysfunction and cerebral amyloid angiopathy (CAA). We investigated whether FGF-2 attenuates EC dysfunction caused by pathological Abeta levels. We studied Abeta1-40 on EC survival, as well as on signals responsible of their angiogenic phenotype. At 5-50 microM Abeta1-40 reduced EC population, caused apoptosis, downregulated FGF-2 production, inhibited FGF-2 binding to heparin, and FGFR1 phosphorylation. Toxic effects were owing to lack of FGF-2 stimulation, as EC overexpressing FGF-2 displayed extraordinary resistance to Abeta1-40 injuries. The FGF-2 mechanism responsible for reversing damages, involves the downstream enhancement of Akt, a pathway independent of eNOS activation. In conclusion, we demonstrate that FGF-2 protects EC from the effects of excess Abeta1-40, suggesting that it may attenuate the consequences of Abeta deposition in pathologies as CAA.