Epigenetic Regulation and its Effects on Aging and Cardiovascular Disease

Emerging Trends in Atherosclerosis: Time to Address Atherosclerosis From a Younger Age

Over the past two decades, research efforts into cardiovascular disease (CVD) have uncovered findings that fundamentally challenge our understanding of CVD, particularly atherosclerosis. Atherosclerosis was primarily attributed to the well-described abnormal lipid accumulation theory, involving plaque growth with subsequent plaque hemorrhage resulting in acute vessel thrombosis that may or may not rupture. This perspective has now evolved to encompass more complex pathways, wherein the accumulation of abnormal products of oxidation and inflammation is the most likely factor mediating atherosclerotic plaque growth. Furthermore, atherosclerosis was traditionally thought of as a disease in patients aged 40 and older. However, mounting evidence has demonstrated that significant atherosclerosis and CVD events are more prevalent in younger patients than previously realized and accelerating in incidence. With this alarming trend among younger individuals, our review sought to explore why this trend may be happening and what can be done about this developing problem.

Rhein alleviates myocardial ischemic injury by inhibiting mitochondrial division, activating mitochondrial autophagy and suppressing myocardial cell apoptosis through the Drp1/Pink1/Parkin pathway

BACKGROUND

Rhein, which has antioxidant and anti-inflammatory response properties, is a beneficial treatment for different pathologies. However, the mechanism by which rhein protects against myocardial ischemic injury is poorly understood.

METHODS AND RESULTS

To establish an acute myocardial infarction (AMI) rat model, we performed left anterior descending (LAD) ligation. Sprague‒Dawley rats were randomly divided into four groups: sham, AMI, AMI + rhein (AMI + R), and AMI + mitochondrial fission inhibitor (AMI + M). The extent of myocardial injury was evaluated by TTC staining, serum myocardial injury markers, and HE and Masson staining. Cardiac mitochondria ultrastructure was visualized by transmission electron microscopy. TUNEL assay and flow cytometry analysis were used to estimate cell apoptosis. Protein expression levels were measured by Western blotting. In vitro, the efficacy of rhein was assessed in H9c2 cells under hypoxic condition. Our results revealed that rats with AMI exhibited increased infarct size and indicators of myocardial damage, along with activation of Drp1-dependent mitochondrial fission, decreased mitophagy and increased apoptosis rates. However, pretreatment with rhein significantly reversed these effects and demonstrated similar efficacy to Mdivi-1. Furthermore, rhein pretreatment protected against myocardial ischemic injury by inhibiting mitochondrial fission, as evidenced by decreased Drp1 expression. It also enhanced mitophagy, as indicated by increased expression of Beclin1, Pink1 and Parkin, an increased LC3-II/LC3-I ratio and increased formation of autolysosomes. Additionally, rhein pretreatment mitigated apoptosis in AMI. These results were also confirmed in vitro in H9c2 cells.

CONCLUSION

Our results demonstrate that rhein pretreatment exerts cardioprotective effects against myocardial ischemic injury via the Drp1/Pink1/Parkin pathway.

Obesity-Induced Hyperglycemia and Heart Failure Preserved Ejection Fraction: Uncharted Territories to Remission

Until the end of World War II, food security was a global challenge. Consequently, in 1948, type 2 diabetes was relatively uncommon, with the majority of cases being type 1 diabetes requiring insulin therapy. Since then, food has become increasingly palatable and readily available, leading to a rise in obesity across all age groups. Understanding the impact of obesity on our health has become crucial for optimizing healthcare. In this context, we draw attention to two significant, yet relatively uncharted pathogenic effects associated with obesity: Hyperglycemia and Heart Failure with Preserved Ejection Fraction (HFpEF). Thorough pathophysiologic, hemodynamic, and echocardiographic characterization have revealed the existence of a distinct phenotype known as "obese HFpEF" within the broader HFpEF population, and "obesity-induced hyperglycemia" within the diabetes population. In these phenotypes, patients often present with higher Body Mass Index and experience clinical symptoms decades earlier. Recent insights have enhanced our understanding of the mechanisms underlying obesity-mediated heart failure preserved ejection fraction and hyperglycemia. Early detection offers the potential for reversibility of many pathologies associated with obesity through adequate weight reduction. The objective of this review is to provide a deeper insight into these uncharted territories and explore the potential for improved outcomes by reframing these two narratives toward achieving remission. Such a shift has the potential to positively impact individual engagement with healthier lifestyles.