EphA4 activity stimulates retinal stem cells proliferation and regulates their sorting iN vitro

CINDY LORENA OLMOS CARREÑO; LUCIANO FIORE; MARIA AGUSTINA SCARAFIA; JUAN GUILLERMO MAHECHA CASTAÑEDA; LUANA SADER LIMA; NESTOR CARRI; VIVIANA SANCHEZ; GABRIEL SCICOLONE

Mar del Plata

Congreso; XXX Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias (SAN); 2015

Sociedad Argentina de Investigación en Neurociencias

The chicken embryonic retina presents multipotent stem cells in the ciliary zone (CZ).We showed that stem cells express molecules of the Eph-ephrin system. We investigated whether the EphA4 expressed in retinal neurospheres regulates proliferation of stem cells obtained from CZ and whether these stem cells express positional information.We cultured dissociated cells obtained from chicken embryonic nasal and temporal CZ,favoring neurospheres formation. We added BrdU to detect proliferating cells and compared nasal and temporal control neurospheres with nasal and temporal neurospheres treated with Kyl peptide (specific inhibitor of EphA4).We compared the distribution of BrdU + cells, the ratio of BrdU + cells /Hoechst + nucleous, the level of activated EphA4 and the expression of topographic markers (FoxG1 and ephin-A5 for nasal retina).It was shown that: 1) BrdU + cells concentrate in the peripheral zone of neurospheres; 2) partial inhibition of EphA4 activity reduces the proportion of proliferating cells by reducing its density in the peripheral zone, changing their peripheral location to a more homogeneous distribution. 3) It was also shown that nasal neurospheres express higher levels of FoxG1 and ephrin-A5 such as the case for nasal retina.Results show that EphA4 activity not only increases stem cells proliferation but also favors sorting of proliferating cells. Besides, they show that stem cells express positional information.