β-adrenergic over-stimulation and cardio-myocyte apoptosis: two receptors, one organelle, two fates?

Curr Drug Targets. 2014;15(10):956-64.

Abstract

Neuro-hormonal regulation of cardiac function via cathecol-amines results in increased heart rate and contractility. A persistent adrenergic tone, however, is an insult to the heart, affecting its regular homeostasis, altering morphology and gene expression patterns, as well as inducing apoptosis of cardio-myocytes. At the same time as being the main oxygen consumers, mitochondria are also key to the energy production required for the heart to maintain its vital functions and to integrate a series of signaling pathways that define the life and death of the cell. As α-adrenergic receptors (α-AR) orchestrate multiple biochemical events that can either trigger or inhibit cell death, mitochondria can act as a referee in the entire process. In fact, α-AR subtypes α1 and α2 activate various down-stream pathways which differently modulate intracellular calcium levels and production of mitochondrial reactive oxygen species (ROS). The delicate balance between an adaptive (cardio-protective) response resulting in increased contractility and activation of survival pathways, vs. cell death caused by calcium and ROS-induced mitochondrial disruption, along with evidence of their clinical and potential therapeutic translations, are reviewed in this communication.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Apoptosis*
  • Calcium / metabolism
  • Catecholamines / pharmacology*
  • Humans
  • Mitochondria / metabolism*
  • Myocytes, Cardiac / metabolism*
  • Myocytes, Cardiac / pathology
  • Reactive Oxygen Species / metabolism
  • Receptors, Adrenergic, beta / metabolism*
  • Signal Transduction

Substances

  • Catecholamines
  • Reactive Oxygen Species
  • Receptors, Adrenergic, beta
  • Calcium