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Mitochondria Modulates Calcium Pulsars Kinetics in Native Endothelial Cells from Mouse Mesenteric Arteries
Author(s) -
Toussaint Fanny,
Béziau Delphine,
Charbel Chimène,
Blanchette Alexandre,
Mayer Gaétan,
Ledoux Jonathan
Publication year - 2016
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.30.1_supplement.727.3
Subject(s) - mitochondrion , biology , pulsar , calcium , mesenteric arteries , microbiology and biotechnology , bursting , biophysics , population , medicine , neuroscience , physics , environmental health , artery , astrophysics
Endothelial control of vascular tone is modulated by local calcium (Ca 2+ ) signaling events like Ca 2+ pulsars, an IP 3 R‐dependant Ca 2+ release restricted to myoendothelial projections (MEP). Aside from the recent report of Ca 2+ pulsars being modulated by CaMKII, mechanisms regulating endothelial spontaneous Ca 2+ release remain unidentified. Mitochondria are important modulators of intracellular Ca 2+ dynamics in various cell types and, we hypothesized mitochondria may control endothelial Ca 2+ pulsars. High‐speed confocal microscopy was used to investigate mitochondria's influence on endothelial Ca 2+ pulsar in cut‐open mouse mesenteric arteries ( en face configuration). Preventing mitochondrial Ca 2+ uptake by uncoupling with FCCP uncovered a new Ca 2+ pulsar site population that had a lower frequency (≈+30%) but larger diffusional spread (+57%) than controls. Inhibition of mitochondrial Ca 2+ uptake via the uniporter using Ru360 increased the spread of Ca 2+ pulsars (≈+30%), though kinetics were not significantly altered. Significantly, inhibition of mitochondrial Ca 2+ export (CGP37157, CsA) increased the number of active Ca 2+ pulsar sites, each with a decreased bursting frequency. In summary, these results suggest that mitochondrial uptake and release of Ca 2+ acts as a critical local modulator of Ca 2+ pulsar kinetics and may therefore be crucial to endothelial control of vascular tone. Support or Funding Information FRQS, HSFC, CFI, SQHA and CIHR