PI3K/Akt, MAPK Erk1/2 and NFkB are involved in G-CSF-induced MMP-2 activity and VEGF secretion in a human trophoblastic cell line

FURMENTO VERÓNICA A.; MARINO JULIETA; ROGUIN LEONOR

Bariloche

Simposio; Second South American Spring Symposium in Signal Transduction and Molecular Medicine (SISTAM); 2012

Granulocyte-Colony Stimulating Factor (G-CSF) is a potent hematopoietic factor that exerts its role through its interaction with the cell surface G-CSF Receptor (G-CSFR). The presence of G-CSFR has been reported in the myeloid linage, but it has also been detected in placental tissue cells. The relevance of G-CSF signaling and regulation in placental tissue still remains to be studied. Previously, we have demonstrated that the presence of functional G-CSF receptors is related to an increase in the activity of metalloproteinase-2 (MMP-2) and the levels of Vascular Endothelial Growth Factor (VEGF) in the human Swan71 trophoblastic cell line. The aim of this work was to examine the involvement of some signaling pathways in these biological outputs.When we studied MAPK Erk1/2 and Akt phosphorilation kinetics, Western blot (WB) assays showed that maximum levels of MAPK Erk1/2 and Akt phosphorilation were obtained after 60 and 15 minutes of incubation with 1 µg/ml of G-CSF, respectively. We also studied whether NFkB was activated. WB assays revealed that NFkB inhibitor levels significantly diminished after 16 hr of incubation with 1 µg/ml of G-CSF. In addition, WB and inmunocitochemistry assays showed that NFkB translocated to the nucleus after 24 hr of incubation with G-CSF. On the other hand, results obtained by using specific signaling pathways inhibitors such as PD 98059, Ly 294002 and Bay 11-7082 suggested that the three pathways would be participating in the biological actions triggered by the cytokine.In conclusion, our data suggest that G-CSF activates PI3K/Akt, MAPK Erk1/2 and NFkB pathways in the human Swan71 trophoblastic cell line. These pathways would be implicated in the G-CSF-induced increase of MMP-2 activity and VEGF secretion.