Thioredoxin 2 protects mice against experimental myocardial infarction

Abstract

Graphical abstract Experimental Myocardial infarction (MI) using ligation procedure induces cardiac dysfunction, high level of ROS, inflammation, apoptosis, fibrosis and cardiomyocyte (CM) loss. AAV overexpressing human Trx-2, specifically in CM mitochondria improves mouse cardiac function, reduces the size of cardiac infarct, increases the expression of cardiac anti-inflammatory markers, reduces apoptosis and oxidative stress. However, it does not increase CM proliferation. Abstract Introduction and objective Myocardial infarction (MI), which in general results from complications of atherosclerosis, is characterized by high inflammation and cardiomyocytes (CMs) apoptosis and by major loss of CMs. Regeneration of these lost CMs represents a major challenge for MI therapy. The increase of mitochondrial reactive oxygen species (ROS) is involved in cell cycle arrest which can be restarted by hypoxia or in the presence of ROS scavengers. Among ROS scavengers, mitochondrial thioredoxin 2 (Trx-2), an important antioxidant protein, could play a role in the CMs renewal. Method In this study, we investigated the effect of Trx-2 on mouse heart after an experimental MI. Results Trx-2 improves mouse cardiac function, reduces cardiac infarction size and increases the expression of cardiac anti-inflammatory markers. In addition, it reduces apoptosis and oxidative stress in heart tissue of mice after MI but it does not increase CM proliferation in cell culture or in heart tissue. Conclusion Mitochondrial Trx-2 effectively protects against heart infarction, likely via the reduction of oxidative stress, inflammation and apoptosis but not through CM renewal. Significance statement The current study unveils the complexities of MI and highlights mitochondrial Trx-2 role. Post-MI, marked by inflammation, CM apoptosis and significant CM loss. Trx-2 emerges as a vital protector. Its intervention improves mouse cardiac function, reduces infarction size and fosters an anti-inflammatory environment. By uncovering these mechanisms, the study suggests potential therapeutic strategies for oxidative stress, inflammation and apoptosis in MI, positioning Trx-2 as a promising candidate for future cardiac interventions.