Mitochondria in Pathological Cardiac Remodeling

Circulating mitochondrial biomarkers in acute coronary syndrome

Background

Acute coronary syndrome (ACS) is the leading cause of mortality in developed countries. Mitochondrial dysfunction is a hallmark of various cardiometabolic diseases, including ACS. Emerging evidence suggests that evaluating mitochondrial biomarkers in plasma may offer valuable insights into the pathophysiology and management of these conditions. The present study aims to analyse the effect of ACS, sex and their interaction on plasma levels of mitochondrial markers, such as peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), mitochondrial open reading frame of the 12S rRNA type-c (MOTS-c) and citrate syntetase (CS).

Methods

A total of 18 ACS patients (8 women and 10 men) and 20 controls (8 women and 12 men) were included in this study. Venous blood samples were collected from participants after a 12-h overnight fast. Plasma levels of mitochondrial PGC-1α, MOTS-c and CS were measured.

Results

ACS significantly reduced plasma levels of PGC-1α and MOTS-c. Sex did not shown a significant effect on these markers. Additionally, MOTS-c positively correlated with the first troponin and hemoglobin, PGC-1α negatively correlated with glucose and positively with HDL-cholesterol, and CS showed negative correlations with NT-proBNP, C-reactive protein, and hemoglobin.

Conclusion

Mitochondria markers, MOTS-c and PGC-1α, are altered in ACS patients, with no observed sex differences. These findings represent an initial step toward integrating personalized medicine into the clinical management of ACS. Nonetheless, further studies are required to fully elucidate the role of these markers in this pathology.

Mitochondrial transplantation for cardioprotection and induction of angiogenesis in ischemic heart disease

To date, the regenerative potential of mitochondrial transplantation (MT) has been extensively investigated under several pathologies. Among various cardiovascular diseases, ischemic heart disease (IHD), the most prevalent pathological condition in human medicine, is induced by coronary artery narrowing, or occlusion, leading to bulk necrotic changes and fibrosis within the myocardium. Data associated with the pro-angiogenic activity of mitochondria have not been completely elucidated in terms of cardiac tissue regeneration. Here, we aimed to highlight the recent studies and advantages related to the application of mitochondrial mass in the ischemic myocardium. How and by which mechanisms, mitochondria can reduce aberrant myocardial tissue remodeling via different pathways such as angiogenesis and de novo blood formation was discussed in detail. We hope that data from the current review article help us understand the molecular and cellular mechanisms by which transplanted mitochondria exert their regenerative properties in the ischemic myocardium.

Mitochondrial calcium signaling and redox homeostasis in cardiac health and disease

The energy demand of cardiomyocytes changes continuously in response to variations in cardiac workload. Cardiac excitation-contraction coupling is fueled primarily by adenosine triphosphate (ATP) production by oxidative phosphorylation in mitochondria. The rate of mitochondrial oxidative metabolism is matched to the rate of ATP consumption in the cytosol by the parallel activation of oxidative phosphorylation by calcium (Ca2+) and adenosine diphosphate (ADP). During cardiac workload transitions, Ca2+ accumulates in the mitochondrial matrix, where it stimulates the activity of the tricarboxylic acid cycle. In this review, we describe how mitochondria internalize and extrude Ca2+, the relevance of this process for ATP production and redox homeostasis in the healthy heart, and how derangements in ion handling cause mitochondrial and cardiomyocyte dysfunction in heart failure.