Nicotinamide adenine dinucleotide inhibits the production of reactive oxygen species and myocardial cell pyroptosis caused by hypoxia/re-oxygenation injury

BACKGROUND Myocardial ischemia/reperfusion (I/R) is a significant factor that negatively impacts the treatment outcomes of coronary heart disease, particularly acute myocardial infarction. The oxidized form of nicotinamide adenine dinucleotide (NAD) - NAD+ is crucial for various cellular functions. AIM To explore the effects and mechanisms of NAD+ on cell death caused by hypoxia/re-oxygenation (H/R) injury in H9c2 cells. METHODS Cell viability was assessed using the Cell Counting Kit-8 assay. Apoptosis in H9c2 cells was evaluated through terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling staining. Intracellular reactive oxygen species levels were measured with the fluorescent probe dichloro-dihydrofluorescein diacetate. Intracellular NAD+ levels were quantified using a NAD/NAD reduced form assay kit. The impact of NAD+ on the expression of NOD-like receptor pyrin domain-containing 3, apoptosis-associated speck-like protein containing a CARD, and caspase-1 was analyzed by reverse transcription polymerase chain reaction and western blotting. RESULTS The study demonstrated that NAD+ supplementation protects H9c2 cells from H/R induced cell pyroptosis. Mechanistically, external NAD+ reduces H/R induced pyroptosis in H9c2 cells by inhibiting the NOD-like receptor pyrin domain-containing 3 inflammasome. CONCLUSION These results indicate that NAD+ supplementation may serve as a promising therapeutic strategy for I/R injury.