TY - JOUR
T1 - Inhibition of the Na+/H+ antiporter induces cell death in TF-1 erythroleukemia cells stimulated by the stem cell factor
AU - Acevedo-Olvera, Leonardo Fermin
AU - Diaz-Garcia, Hector
AU - Parra-Barrera, Alberto
AU - Caceres-Perez, Alejandro Arturo
AU - Gutierrez-Iglesias, Gisela
AU - Rangel-Corona, Rosalva
AU - Caceres-Cortes, Julio Roberto
N1 - Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015/9/1
Y1 - 2015/9/1
N2 - Leukemia cells produce acidic metabolites due to their high metabolic condition. An alkaline pHi (intracellular pH) shift, caused by activation of the Na+/H+ exchange, is an important event in the mechanism of growth factor activity. However, the role of the Na(+)/H(+) exchanger in the survival of erythroleukemia TF-1 cells has not yet been studied in detail. The aim of this study was to identify the effects of 5-(N-ethyl-N-isopropyl) amiloride (EIPA), a highly specific blocker of the Na(+)/H(+) exchanger, on the survival of SCF-dependent TF-1 cells. The effects of EIPA on survival and mitochondrial membrane potential were studied when exposing wild type TF-1 cells and TF-1 cells expressing bcl-2 to EIPA for 48 h. Ectopic expression of the bcl-2 gene maintained a mildly alkaline pH and prevented the simultaneous appearance of apoptosis and autophagy (typically displayed by TF-1 cells) in the presence of EIPA. Consistent with Stem Cell Factor (SCF) function, we found that this molecule rescued TF-1 cells during autophagy but not apoptosis, allowing these cells to subsequently respond to GM-CSF. Serum deprivation or SCF withdrawal induced cell death at 36 h in TF-1 and TF-1 neo cells, whereas TF-1/bcl-2 cells tended to undergo apoptosis and show acidic vacuoles after 96 h, pointing to a transient anti-apoptotic effect. The present study shows the suppressive effect of EIPA on the proliferation of leukemia cell line stimulated with SCF, apparently by decreasing the mitochondria membrane potential and averting alkalinization. Through the constitutive expression of bcl-2, TF-1 cells were survival factor independent. Proliferation in these cells was not affected by EIPA at the concentrations used against parental TF-1 cells, indicating that the inhibitory effect in SCF-stimulated cells can be attributed to specific blocking of the Na(+)/H(+) exchanger.
AB - Leukemia cells produce acidic metabolites due to their high metabolic condition. An alkaline pHi (intracellular pH) shift, caused by activation of the Na+/H+ exchange, is an important event in the mechanism of growth factor activity. However, the role of the Na(+)/H(+) exchanger in the survival of erythroleukemia TF-1 cells has not yet been studied in detail. The aim of this study was to identify the effects of 5-(N-ethyl-N-isopropyl) amiloride (EIPA), a highly specific blocker of the Na(+)/H(+) exchanger, on the survival of SCF-dependent TF-1 cells. The effects of EIPA on survival and mitochondrial membrane potential were studied when exposing wild type TF-1 cells and TF-1 cells expressing bcl-2 to EIPA for 48 h. Ectopic expression of the bcl-2 gene maintained a mildly alkaline pH and prevented the simultaneous appearance of apoptosis and autophagy (typically displayed by TF-1 cells) in the presence of EIPA. Consistent with Stem Cell Factor (SCF) function, we found that this molecule rescued TF-1 cells during autophagy but not apoptosis, allowing these cells to subsequently respond to GM-CSF. Serum deprivation or SCF withdrawal induced cell death at 36 h in TF-1 and TF-1 neo cells, whereas TF-1/bcl-2 cells tended to undergo apoptosis and show acidic vacuoles after 96 h, pointing to a transient anti-apoptotic effect. The present study shows the suppressive effect of EIPA on the proliferation of leukemia cell line stimulated with SCF, apparently by decreasing the mitochondria membrane potential and averting alkalinization. Through the constitutive expression of bcl-2, TF-1 cells were survival factor independent. Proliferation in these cells was not affected by EIPA at the concentrations used against parental TF-1 cells, indicating that the inhibitory effect in SCF-stimulated cells can be attributed to specific blocking of the Na(+)/H(+) exchanger.
KW - Apoptosis
KW - Autophagy
KW - Na(+)/H(+) exchanger
KW - Stem cell factor
KW - TF-1 cells
UR - http://www.scopus.com/inward/record.url?scp=84938677663&partnerID=8YFLogxK
U2 - 10.1016/j.cyto.2015.06.020
DO - 10.1016/j.cyto.2015.06.020
M3 - Artículo
SN - 1043-4666
VL - 75
SP - 142
EP - 150
JO - Cytokine
JF - Cytokine
IS - 1
ER -