Desmosomal Junctions and Connexin-43 Remodeling in High-Pacing-Induced Heart Failure Dogs

Ion channel trafficking implications in heart failure

Heart failure (HF) is recognized as an epidemic in the contemporary world, impacting around 1%-2% of the adult population and affecting around 6 million Americans. HF remains a major cause of mortality, morbidity, and poor quality of life. Several therapies are used to treat HF and improve the survival of patients; however, despite these substantial improvements in treating HF, the incidence of HF is increasing rapidly, posing a significant burden to human health. The total cost of care for HF is USD 69.8 billion in 2023, warranting a better understanding of the mechanisms involved in HF. Among the most serious manifestations associated with HF is arrhythmia due to the electrophysiological changes within the cardiomyocyte. Among these electrophysiological changes, disruptions in sodium and potassium currents' function and trafficking, as well as calcium handling, all of which impact arrhythmia in HF. The mechanisms responsible for the trafficking, anchoring, organization, and recycling of ion channels at the plasma membrane seem to be significant contributors to ion channels dysfunction in HF. Variants, microtubule alterations, or disturbances of anchoring proteins lead to ion channel trafficking defects and the alteration of the cardiomyocyte's electrophysiology. Understanding the mechanisms of ion channels trafficking could provide new therapeutic approaches for the treatment of HF. This review provides an overview of the recent advances in ion channel trafficking in HF.

[The role of imbalance of myocardial cell adhesion proteins in cardiac arrhythmia and heart failure]

A review of the literature data on the role of imbalance of cellular adhesion proteins (CAP) of the heart in the development of cardiac arrhythmias and heart failure. The CAPS of the intercalated discs belonging to the cadherin and desmin groups provide a mechanical connection of cardiomyocytes, proteins from the connexin group are responsible for the transmission of an electrical impulse. The imbalance of CAP has mainly a hereditary origin and is accompanied by the destruction of intercalated discs, blockage of impulse transmission with the development of electrical instability of the myocardium and cardiac arrhythmias, including ventricular and atrial fibrillation. This is the case with cardiomyopathies, coronary heart disease. Endothelial dysfunction also plays an essential role in atrial fibrillation, which is associated with an imbalance in the CAP of the endothelial lining of the endocardium and blood vessels.