Mechanosensitivity of microdomain calcium signalling in the heart

Patrick Schonleitner, Uli Schotten, Gudrun Antoons*

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

14 Citations (Web of Science)

Abstract

In cardiac myocytes, calcium (Ca2+) signalling is tightly controlled in dedicated microdomains. At the dyad, i.e. the narrow cleft between t-tubules and junctional sarcoplasmic reticulum (SR), many signalling pathways combine to control Ca2+-induced Ca2+ release during contraction. Local Ca2+ gradients also exist in regions where SR and mitochondria are in close contact to regulate energetic demands. Loss of microdomain structures, or dysregulation of local Ca2+ fluxes in cardiac disease, is often associated with oxidative stress, contractile dysfunction and arrhythmias. Ca2+ signalling at these microdomains is highly mechanosensitive. Recent work has demonstrated that increasing mechanical load triggers rapid local Ca2+ releases that are not reflected by changes in global Ca2+. Key mechanisms involve rapid mechanotransduction with reactive oxygen species or nitric oxide as primary signalling molecules targeting SR or mitochondria microdomains depending on the nature of the mechanical stimulus. This review summarizes the most recent insights in rapid Ca2+ microdomain mechanosensitivity and re-evaluates its (patho)physiological significance in the context of historical data on the macroscopic role of Ca2+ in acute force adaptation and mechanically-induced arrhythmias. We distinguish between preload and afterload mediated effects on local Ca2+ release, and highlight differences between atrial and ventricular myocytes. Finally, we provide an outlook for further investigation in chronic models of abnormal mechanics (eg post-myocardial infarction, atrial fibrillation), to identify the clinical significance of disturbed Ca2+ mechanosensitivity for arrhythmogenesis. (C) 2017 Published by Elsevier Ltd.

Original languageEnglish
Pages (from-to)288-301
Number of pages14
JournalProgress in Biophysics & Molecular Biology
Volume130
DOIs
Publication statusPublished - Nov 2017

Keywords

  • Preload
  • Afterload
  • Calcium sparks
  • Microdomains
  • Mechanotransduction
  • Stretch-induced arrhythmias
  • RAT ATRIAL MYOCYTES
  • PIG VENTRICULAR MYOCYTES
  • SLOW FORCE RESPONSE
  • NITRIC-OXIDE SYNTHASE
  • INTRACELLULAR CA2+ TRANSIENTS
  • STRETCH-INDUCED ARRHYTHMIAS
  • INOSITOL 1,4,5-TRISPHOSPHATE RECEPTORS
  • TRIGGERED PROPAGATED CONTRACTIONS
  • MECHANO-CHEMO-TRANSDUCTION
  • CARDIAC MYOCYTES

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