Leishmania amazonensis: heme stimulates (Na(+)+K(+))ATPase activity via phosphatidylinositol-specific phospholipase C/protein kinase C-like (PI-PLC/PKC) signaling pathways.
In the present paper we studied the involvement of the phosphatidylinositol-specific PLC (PI-PLC)/protein kinase C (PKC) pathway in (Na(+)+K(+))ATPase stimulation by heme in Leishmania amazonensis promastigotes. Heme stimulated the PKC-like activity with a concentration of 50nM. Interestingly, the maximal stimulation of the PKC-like activity promoted by phorbol ester was of the same magnitude promoted by heme. However, the stimulatory effect of heme is completely abolished by ET-18-OCH(3) and U73122, specific inhibitors of PI-PLC. (Na(+)+K(+))ATPase activity is increased in the presence of increased concentrations of heme, being maximally affected at 50nM. This effect was completely reversed by 10nM calphostin C, an inhibitor of PKC. Thus, the effect of 50nM heme on (Na(+)+K(+))ATPase activity is completely abolished by ET-18-OCH(3) and U73122. Taken together, these results demonstrate that the heme receptor mediates the stimulatory effect of heme on the (Na(+)+K(+))ATPase activity through a PI-PLC/PKC signaling pathway.
Almeida-Amaral
Elmo Eduardo
EE
Laboratório de Bioquímica de Tripanosomatideos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz - FIOCRUZ, Pavilhão Leônidas Deane, 4 degrees andar, sala 405, Manguinhos, 21045-900 Rio de Janeiro, RJ, Brazil.
Cardoso
Viviane Carrozino
VC
Francioli
Fernanda Gomes
FG
Meyer-Fernandes
José Roberto
JR
D004963:Estrenes / Q000494:pharmacology; D006418:Heme / Q000494:pharmacology*; D007894:Leishmania mexicana / Q000187:drug effects* / Q000201:enzymology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D054801:Phosphoinositide Phospholipase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010742:Phospholipid Ethers / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D011760:Pyrrolidinones / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects / Q000378:metabolism*
D004963:Estrenes; D010726:Phosphodiesterase Inhibitors; D010742:Phospholipid Ethers; D011760:Pyrrolidinones; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; C026659:edelfosine; D006418:Heme; D011493:Protein Kinase C; D054801:Phosphoinositide Phospholipase C; D000254:Sodium-Potassium-Exchanging ATPase