Role of Ca[superscript 2+] in the Control of H[subscript 2]O[subscript 2-]Modulated Phosphorylation Pathways Leading to eNOS Activation in Cardiac Myocytes
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Sartoretto-2012-Role of Ca2+ in the.pdf
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Author(s)
Sartoretto, Juliano L.
Kalwa, Hermann
Shiroto, Takashi
Sartoretto, Simone M.
Pluth, Michael D.
Lippard, Stephen J.
Michel, Thomas
Date Issued
September 2012
Journal
PLoS ONE
Publisher
Public Library of Science
Citation
Sartoretto, Juliano L. et al. “Role of Ca[superscript 2+] in the Control of H[subscript 2]O[subscript 2-]Modulated Phosphorylation Pathways Leading to eNOS Activation in Cardiac Myocytes.” Ed. Gianfranco Pintus. PLoS ONE 7.9 (2012): e44627.
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Final published version
Abstract
Nitric oxide (NO) and hydrogen peroxide (H[subscript 2]O[subscript 2]) play key roles in physiological and pathological responses in cardiac myocytes. The mechanisms whereby H[subscript 2]O[subscript 2]–modulated phosphorylation pathways regulate the endothelial isoform of nitric oxide synthase (eNOS) in these cells are incompletely understood. We show here that H[subscript 2]O[subscript 2] treatment of adult mouse cardiac myocytes leads to increases in intracellular Ca[superscript 2+] ([Ca[superscript 2+]][superscript i]), and document that activity of the L-type Ca[superscript 2+] channel is necessary for the H2O2-promoted increase in sarcomere shortening and of [Ca[superscript 2+]][superscript i]. Using the chemical NO sensor Cu[subscript 2](FL2E), we discovered that the H[subscript 2]O[subscript 2]-promoted increase in cardiac myocyte NO synthesis requires activation of the L-type Ca[superscript 2+] channel, as well as phosphorylation of the AMP-activated protein kinase (AMPK), and mitogen-activated protein kinase kinase 1/2 (MEK1/2). Moreover, H[subscript 2]O[subscript 2]-stimulated phosphorylations of eNOS, AMPK, MEK1/2, and ERK1/2 all depend on both an increase in [Ca[superscript 2+]]i as well as the activation of protein kinase C (PKC). We also found that H[subscript 2]O[subscript 2]-promoted cardiac myocyte eNOS translocation from peripheral membranes to internal sites is abrogated by the L-type Ca[superscript 2+] channel blocker nifedipine. We have previously shown that kinase Akt is also involved in H[subscript 2]O[subscript 2]-promoted eNOS phosphorylation. Here we present evidence documenting that H[subscript 2]O[subscript 2]-promoted Akt phosphorylation is dependent on activation of the L-type Ca[superscript 2+] channel, but is independent of PKC. These studies establish key roles for Ca[superscript 2+]- and PKC-dependent signaling pathways in the modulation of cardiac myocyte eNOS activation by H[subscript 2]O[subscript 2].
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
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DOI of Published Version
https://doi.org/10.1371/journal.pone.0044627
