ERYTHROPOIETIN NEUROPROTECTIVE EFFECT ON SHSY5Y CELLS INDUCED TO APOPTOSIS BY TNF-ALPHA

PRÉGI NICOLAS; WENKER SHIRLEY; CHAMORRO MARÍA EUGENIA; PÉREZ LEIRÓS, C; NESSE ALCIRA

Congreso; X Panamerican Association for Biochemistry and Molecular Biology; 2005

X Panamerican Association for Biochemistry and Molecular Biology

The human neuroblastoma SH-SY5Y cells are an excellent model for the study of neuroprotection induced by treatment with human recombinant erythropoietin (Epo). We investigated signaling pathways involved in this Epo effect in a model of apoptosis induced by tumor necrosis factor-alpha (TNF). Apoptosis of SH-SY5Y cells was developed by addition of 25 ng/ml TNF for 24 h and detected by typical morphological changes (Hoechst staining) and DNA laddering. Under this condition, a decrease in Epo receptor (EpoR) expression was observed at mRNA and protein levels, assayed by RT-PCR and Western blot, respectively. The pretreatment for 12 h with 25 U/ml Epo attenuated the signs of apoptosis observed under the effect of TNF while the levels of EpoR expression was recovered. An increased expression of bcl-2 at mRNA and protein levels, but no changes in bcl-x, bax and c-Flip mRNA levels were also detected. An assay in the presence of the inhibitor wortmannin showed that the antiapoptotic effect of Epo was, at least in part, mediated by PI3K. In conclusion, the results show an Epo neuroprotective capacity to antagonize TNF-induced apoptosis in SHSY5Y cells, action that is partially dependent on the modulation of EpoR and also associated with the increased expression of the antiapoptotic protein Bcl-2.