Disturbed Cardiac Metabolism Triggers Atrial Arrhythmogenesis in Diabetes Mellitus: Energy Substrate Alternate as a Potential Therapeutic Intervention.

Atrial fibrillation (AF) is the most common type of sustained arrhythmia in diabetes mellitus (DM). Its morbidity and mortality rates are high, and its prevalence will increase as the population ages. Despite expanding knowledge on the pathophysiological mechanisms of AF, current pharmacological interventions remain unsatisfactory; therefore, novel findings on the underlying mechanism are required.

ZFHX3 knockdown dysregulates mitochondrial adaptations to tachypacing in atrial myocytes through enhanced oxidative stress and calcium overload.

Aim: To investigate the role of zinc finger homeobox 3 gene (ZFHX3) in tachypacing-induced mitochondrial dysfunction and explore its molecular mechanisms and potential as a therapeutic target in atrial fibrillation (AF).

Methods: Through a bioluminescent assay, a patch clamp, confocal fluorescence and fluorescence microscopy, microplate enzyme activity assays and Western blotting, we studied ATP and ADP production, mitochondrial electron transfer chain complex activities, ATP-sensitive potassium channels (I ), mitochondrial oxidative stress, Ca content, and protein expression in control and ZFHX3 knockdown (KD) HL-1 cells subjected to 1 and 5-Hz pacing for 24 hours.

Results: Compared with 1-Hz pacing, 5-Hz pacing increased ATP and ADP production, I , phosphorylated adenosine monophosphate-activated protein kinase and inositol 1,4,5-triphosphate (IP ) receptor (IP R) protein expression.

Pitx2c inhibition increases atrial fibroblast activity: Implications in atrial arrhythmogenesis.

Background: A Pitx2c deficiency increases the risk of atrial fibrillation (AF). Atrial structural remodelling with fibrosis blocks electrical conduction and leads to arrhythmogenesis. A Pitx2c deficiency enhances profibrotic transforming growth factor (TGF)-β expression and calcium dysregulation, suggesting that Pitx2c may play a role in atrial fibrosis.

Activation of Class I histone deacetylases contributes to mitochondrial dysfunction in cardiomyocytes with altered complex activities.

Histone deacetylases (HDACs) play vital roles in the pathophysiology of heart failure, which is associated with mitochondrial dysfunction. Tumor necrosis factor-α (TNF-α) contributes to the genesis of heart failure and impairs mitochondria. This study evaluated the role of HDACs in TNF-α-induced mitochondrial dysfunction and investigated their therapeutic potential and underlying mechanisms.

Targeting histone deacetylases: A novel therapeutic strategy for atrial fibrillation.

Atrial fibrillation (AF) is a common cardiac arrhythmia associated with high mortality and morbidity. Current treatments of AF have limited efficacy and considerable side effects. Histone deacetylases (HDACs) play critical roles in the pathophysiology of cardiovascular diseases and contribute to the genesis of AF.