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.

Hypoxia/re-oxygenation; Ischemia/reperfusion injury; Nicotinamide adenine dinucleotide; Oxidative stress; Pyroptosis.