RESUMEN
Inflammasome activation and pyroptotic cell death are known to contribute to the pathogenesis of cardiovascular diseases, such as myocardial ischemia-reperfusion (I/R) injury, although the underlying regulatory mechanisms remain poorly understood. Here we report that expression levels of the E3 ubiquitin ligase membrane-associated RING finger protein 2 (MARCH2) were elevated in ischemic human hearts or mouse hearts upon I/R injury. Genetic ablation of MARCH2 aggravated myocardial infarction and cardiac dysfunction upon myocardial I/R injury. Single-cell RNA-seq analysis suggested that loss of MARCH2 prompted activation of NLRP3 inflammasome in cardiomyocytes. Mechanistically, phosphoglycerate mutase 5 (PGAM5) was found to act as a novel regulator of MAVS-NLRP3 signaling by forming liquid-liquid phase separation condensates with MAVS and fostering the recruitment of NLRP3. MARCH2 directly interacts with PGAM5 to promote its K48-linked polyubiquitination and proteasomal degradation, resulting in reduced PGAM5-MAVS co-condensation, and consequently inhibition of NLRP3 inflammasome activation and cardiomyocyte pyroptosis. AAV-based re-introduction of MARCH2 significantly ameliorated I/R-induced mouse heart dysfunction. Altogether, our findings reveal a novel mechanism where MARCH2-mediated ubiquitination negatively regulates the PGAM5/MAVS/NLRP3 axis to protect against cardiomyocyte pyroptosis and myocardial I/R injury.
RESUMEN
Aging is a complex irreversible biological process associated with increased prevalence of chronic disease and high healthcare burden. Several theories have been proposed for the biology of aging including free radical accumulation, DNA damage, apoptosis, telomere shortening, autophagy failure, and disturbed autonomic response. Aging is also closely associated with progressive deterioration of cardiovascular and neurological functions. Linkage, genome-wide association (GWAS), and next-generation sequencing analysis have confirmed a number of susceptibility loci for aging, in particular, Alzheimer's disease. Recent evidence from our group and others also revealed a tie between genetic mutation of mitochondrial aldehyde dehydrogenase (ALDH2) and life span as well as cardiovascular aging. ALDH2 represents the single most gene with the greatest number of human genetic polymorphism and is deemed an important enzyme for detoxification of reactive aldehydes. Here, we will briefly review the tie between ALDH2 and cardiovascular aging process. While recent work on ALDH2 research has broadened the pathogenic mechanisms of ALDH2 mutation or deficiency, therapeutic potential targeting ALDH2 in the elderly still remains debatable.