Regeneration of the Olfactory Epithelium. Role of Wnt and Sox2 in the differentiation of the olfactory receptors neurons

FRONTERA, JIMENA; CERVINO, AILEN; PAZ, DANTE

Huerta Grande. Cordoba

Congreso; XXVIII Congreso de la Sociedad Argentina de Investigación en Neurociencias & Reunión Satélite: ?Bases Neurales de la Conducta: Neuroetología y Neurobiología de la Memoria en el Cono Sur?; 2013

Sociedad Argentina de Investigación en Neurociencias

The olfactory epithelium (OE) has been known for its capability of actively generating olfactory receptor neurons throughout adulthood, and rapid neuronal regeneration after extensive damage to the tissue, due to the presence of neural stem cells (NSC) in the basal layer of the OE. Wnt promotes cell proliferation and regulates neurogenesis in multiple tissues. In the other hand, during neurogenesis, Sox2 antagonizes proneural genes in order to maintain progenitors. Therefore, in the last years a directional Wnt-Sox2-proneural pathway has been investigated in order to describe the regulation of the transition from proliferation to differentiation of NSC .In the present study, we analyzed the Sox2 expression in the olfactory basal cells and the activation of Wnt signaling pathways in normal and regenerating OE. We found that sox2 expression is significantly increased during extensive regeneration and would be regulated by Wnt. Immunohistochemistry and qRT-PCR showed that after Wnt inhibition, sox2 expression is significantly decreased during OE regeneration. Analysis of Wnt/B-catenin signaling pathway showed that B-catenin is not trans-located in to the nucleus in the Sox2+ cells. Moreover, analysis of Wnt/JNK pathway activation through the immunodetection of pJnk showed that neither this signaling would be activated by Wnt in the sox2+ basal cells. These results suggest that Wnt is regulating Sox2 expression in OE basal cells although through activation of another Wnt signaling pathway were B-catenin and pJNK are not involved.