EphA3 ectodomain and uPA increase retinal ganglion cells axon growth by regulating FAK activity.

MEDORI, MARA; OLMOS CARREÑO, CINDY LORENA; SCICOLONE, GABRIEL; SPELZINI, GONZALO; SANCHEZ, VIVIANA; TERUEL, LUISA R; FIORE, LUCIANO

Villa Carlos Paz

Congreso; XXXIV Reunion Anual SAN 2019; 2019

Sociedad Argentina de Investigacion en Neurociencias

The Eph/ephrin system regulates axon guidance during chicken retinotectal mapping. We demonstrated that tectal EphA3 stimulates axon growth of nasal retinal ganglion cells (RGC) toward the caudal tectum preventing them from branching in the rostral tectum. The complex formed by urokinase plasminogen activator (uPA) and its receptor (uPAR) promotes neuritogenesis and is closely related to the phosphorylation of the focal adhesion kinase (FAK).The purposes of this work were to study the relationship between the effects of EphA3 and uPA on RGC axon growth and which molecules participate downstream in these processes.We cultured chicken embryo dissociated retinal neurons and retinal explants exposed to control conditions, to EphA3 ectodomain (EphA3-Fc), to uPA or to EphA3-Fc plus uPA to evaluate their effects on axon growth and on FAK activity. The results showed that: uPA produces a higher increase in axon growth than the EphA3-Fc and that the combination of both of them produces an intermediate effect. Besides uPA and EphA3-Fc modify FAK activity in a different way.This shows that uPA and EphA3 increase RGC axon growth in a non-additive way and that both of them regulate FAK activity.