Antiapoptotic activity of Stat5 required during terminal stages of myeloid differentiation.
Genes Dev
; 14(2): 232-44, 2000 Jan 15.
Article
em En
| MEDLINE
| ID: mdl-10652277
ABSTRACT
Stat5 is activated by multiple receptors of hematopoietic cytokines. To study its role during hematopoiesis, we have generated primary chicken myeloblasts expressing different dominant-negative (dn) alleles of Stat5. This caused a striking inability to generate mature cells, due to massive apoptosis during differentiation. Bcl-2 was able to rescue differentiating cells expressing dnStat5 from apoptosis, suggesting that during cytokine-dependent differentiation the main function of the protein is to ensure cell survival. Our findings with dnStat5-expressing chicken myeloblasts were confirmed with primary hematopoietic cells from Stat5a/Stat5b-deficient mice. Bone marrow cells from these animals displayed a strong increase in apoptotic cell death during GM-CSF-dependent functional maturation in vitro. The antiapoptotic protein Bcl-x was induced by GM-CSF and IL-3 in a Stat5-dependent fashion. Ectopic expression of Bcl-x rescued Stat5-deficient bone marrow cells from apoptosis, indicating that Stat5 promotes the survival of myeloid progenitor cells through its ability to induce transcription of the bcl-x gene. Finally, the recruitment of myeloid cells to inflammatory sites was found strongly impeded in Stat5-deficient mice. Taken together, our findings suggest that Stat5 may promote cytokine-dependent survival and proliferation of differentiating myeloid progenitor cells in stress or pathological situations, such as inflammation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transativadores
/
Apoptose
/
Proteínas de Ligação a DNA
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Hematopoese
/
Proteínas do Leite
Limite:
Animals
Idioma:
En
Revista:
Genes Dev
Ano de publicação:
2000
Tipo de documento:
Article