Scientific publications

Erythropoietin can induce the expression of bcl-x(L) through Stat5 in erythropoietin-dependent progenitor cell lines

Silva M, Benito A, Sanz C, Prosper F, Ekhterae D, Nuñez G, Fernandez-Luna JL.
Servicio de Inmunologia, Hospital Universitario Marques de Valdecilla, INSALUD, 39008 Santander, Spain.

Magazine: The Journal of Biological Chemistry

Date: Aug 6, 1999

Cell Therapy Area [SP]

Erythropoietin (Epo) initiates its cellular response by binding to the Epo receptor, which triggers the activation of signal transducer and activator of transcription (Stat) 5 protein. Cell culture studies of erythroid progenitors have suggested that Epo functions as a survival factor by repressing apoptosis at least in part through Bcl-x(L), an anti-apoptotic protein of the Bcl-2 family. In this report, we examine whether Stat5 can induce transactivation of the bcl-x gene in response to Epo. Two Epo-responsive progenitor cell lines, HCD-57 and Bcl-2-transfected Ba/F3-Epo receptor (Ba/F3-EpoR-Bcl-2), were used in this study.

After Epo stimulation, we observed a correlation between expression of bcl-x(L) and activation of Stat5 as assessed by the expression of oncostatin M, a direct target of Stat5, and the phosphorylation and nuclear translocation of Stat5. Moreover, a Stat binding element in the bcl-x promoter was found to be active in response to Epo, a finding that was further confirmed because mutagenesis of this sequence motif abrogated its promoter activity and overexpression of a dominant negative Stat5 protein blocked transactivation. When DNA-protein binding analyses were performed, we found that Stat5, not Stat1 or Stat3, was the protein bound to the bcl-x promoter in response to Epo.

These data suggest that Epo-dependent activation of Stat5 is a transcriptional pathway that can be used by Epo-responsive progenitor cells to induce the expression of bcl-x(L) and consequently to inhibit apoptosis.

CITATION  J Biol Chem. 1999 Aug 6;274(32):22165-9



The Clínica is the greater private hospital with technological equipment of Spain, all in a single center.

Imagen de un PET, tecnología de vanguardia en la Clínica Universidad de Navarra


The professionals of the Clínica perform continuous research and training, always to the benefit of the patient.

Imagen profesionales de la Clínica Universidad de Navarra


Learn why we are different from other healthcare centers. Quality, speed, comfort and results.

Imagen del edificio de la Clínica Universidad de Navarra