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Requirement for PLCγ2 in IL‐3 and GM‐CSF‐stimulated MEK/ERK phosphorylation in murine and human hematopoietic stem/progenitor cells
Author(s) -
Leon Carlos M.M.P.,
Barbosa Christiano M.V.,
Justo Giselle Z.,
Borelli Primavera,
Junior José Dias Resende,
de Oliveira José S.R.,
Ferreira Alice T.,
ParedesGamero Edgar J.
Publication year - 2011
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.22507
Subject(s) - progenitor cell , microbiology and biotechnology , haematopoiesis , stem cell , biology , mapk/erk pathway , signal transduction , cytokine , interleukin 3 , immunology , t cell , il 2 receptor , immune system
Even though the involvement of intracellular Ca 2+ ( ${\rm Ca}_{{\rm i}}^{{\rm 2 + }} $ ) in hematopoiesis has been previously demonstrated, the relationship between ${\rm Ca}_{{\rm i}}^{{\rm 2 + }} $ signaling and cytokine‐induced intracellular pathways remains poorly understood. Herein, the molecular mechanisms integrating Ca 2+ signaling with the extracellular signal‐regulated kinase 1/2 (ERK1/2) pathway in primary murine and human hematopoietic stem/progenitor cells stimulated by IL‐3 and GM‐CSF were studied. Our results demonstrated that IL‐3 and GM‐CSF stimulation induced increased inositol 1,4,5‐trisphosphate (IP 3 ) levels and ${\rm Ca}_{{\rm i}}^{{\rm 2 + }} $ release in murine and human hematopoietic stem/progenitor cells. In addition, ${\rm Ca}_{{\rm i}}^{{\rm 2 + }} $ signaling inhibitors, such as inositol 1,4,5‐trisphosphate receptor antagonist (2‐APB), PKC inhibitor (GF109203), and CaMKII inhibitor (KN‐62), blocked phosphorylation of MEK activated by IL‐3 and GM‐CSF, suggesting the participation of Ca 2+ ‐dependent kinases in MEK activation. In addition, we identify phospholipase Cγ2 (PLCγ2) as a PLCγ responsible for the induction of Ca 2+ release by IL‐3 and GM‐CSF in hematopoietic stem/progenitor cells. Furthermore, the PLCγ inhibitor U73122 significantly reduced the numbers of granulocyte‐macrophage colony‐forming units after cytokine stimulation. Similar results were obtained in both murine and human hematopoietic stem/progenitor cells. Taken together, these data indicate a role for PLCγ2 and Ca 2+ signaling through the modulation of MEK in both murine and human hematopoietic stem/progenitor cells. J. Cell. Physiol. 226: 1780–1792, 2011. © 2010 Wiley‐Liss, Inc.