title: Requirement for PLCγ2 in IL-3 and GM-CSF-stimulated MEK/ERK phosphorylation in murine and human hematopoietic stem/progenitor cells.
abstract: Even though the involvement of intracellular Ca(2+) Ca(i)(2+) in hematopoiesis has been previously demonstrated, the relationship between Ca(i)(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 Ca(i)(2+) release in murine and human hematopoietic stem/progenitor cells. In addition, Ca(i)(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.
authors.affiliation: Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
authors.forename: Carlos M M P
authors.initials: CM
authors.lastname: Leon
authors.forename: Christiano M V
authors.initials: CM
authors.lastname: Barbosa
authors.forename: Giselle Z
authors.initials: GZ
authors.lastname: Justo
authors.forename: Primavera
authors.initials: P
authors.lastname: Borelli
authors.forename: José Dias
authors.initials: JD
authors.lastname: Resende
authors.forename: José S R
authors.initials: JS
authors.lastname: de Oliveira
authors.forename: Alice T
authors.initials: AT
authors.lastname: Ferreira
authors.forename: Edgar J
authors.initials: EJ
authors.lastname: Paredes-Gamero
mesh_terms: D000328:Adult; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D002469:Cell Separation; D002478:Cells, Cultured; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007377:Interleukin-3 / Q000378:metabolism*; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008875:Middle Aged; D051966:Phospholipase C gamma / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D011994:Recombinant Proteins; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004791:Enzyme Inhibitors; C508596:IL3 protein, human; D007377:Interleukin-3; D011994:Recombinant Proteins; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D015544:Inositol 1,4,5-Trisphosphate; D011493:Protein Kinase C; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D048049:Extracellular Signal-Regulated MAP Kinases; D020930:MAP Kinase Kinase Kinases; D051966:Phospholipase C gamma