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Mitochondrial modulation of calcium pulsars in native endothelial cells (1075.3)
Author(s) -
Béziau Delphine,
Charbel Chimène,
Toussaint Fanny,
Blanchette Alexandre,
Mayer Gaétan,
Ledoux Jonathan
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.1075.3
Subject(s) - mitochondrion , microbiology and biotechnology , calcium , pulsar , calcium in biology , biophysics , intracellular , biology , confocal , membrane potential , function (biology) , chemistry , physics , organic chemistry , astrophysics , optics
Calcium homeostasis is the crux of endothelial function and the regulation of vascular tone. Endothelial Ca 2+ is thus highly dynamic and finely tuned. Amongst Ca 2+ dynamics, Ca 2+ pulsars are spontaneous Ca 2+ release by IP 3 receptors within myoendothelial projections (MEP). However, regulatory mechanisms of endothelial Ca 2+ pulsars remain to be determined. Mitochondria play a major role in intracellular Ca 2+ regulation in several cell types and may represent a modulator of endothelial Ca 2+ dynamics like Ca 2+ pulsars. We then hypothesized that mitochondria are active regulators of Ca 2+ pulsars. Given the specific localization of Ca 2+ pulsars, we first established the mitochondrial distribution in native mouse endothelium by confocal and electron microscopy. Mitochondria appeared heterogeneously distributed in endothelial cells but were found to be three times more concentrated near MEP. The functional interaction between mitochondria and Ca 2+ pulsars was then investigated with real‐time confocal microscopy. Interestingly, mitochondrial uncouplers FCCP and CCCP significantly decreased Ca 2+ pulsars frequency. Our data suggest that mitochondria are clustered near MEP to modulate Ca 2+ pulsars and might therefore be an important regulator of endothelial function. Grant Funding Source : Supported by FRQS, HSFC, CFI, SQHA and CIHR.