The role of H2S in isoproterenol-induced cardiac hypertrophy: A comparative study using slow releaser GYY4137 and a newly synthetized fast releaser BM-112.

Cardiac hypertrophy is a compensatory response often associated with cardiovascular diseases. While myocardial hypertrophy provides some advantages at the initial stages of these conditions, sustained hypertrophy can damage the heart, leading to arrhythmia and heart failure. An increasing number of H2S donors, with diverse chemical and pharmacological properties, have been identified as potential therapeutic agents against oxidative stress and myocardial hypertrophy, with the possibility of regulating autophagy. The aim of this project was to investigate the effect of H2S on isoproterenol (ISO)-induced cardiac hypertrophy and oxidative stress, as well as its impact on mitochondrial function and autophagy. As exogenous H2S sources, we employed a newly synthesized fast H2S-releasing aspirin derivative (BM-112) and GYY4137 a known slow releasing donor. Our results confirmed that H2S was successfully released from BM-112 in a cell culture medium, and each compound enhanced significantly the intracellular level of H2S, as measured using the HSip-1 DA probe. Biocompatibility of BM-112 was assessed using MTT assay, which showed no cytotoxic effect on H9c2 at concentrations below 50 µM. Both H2S releasing molecules, BM-112 and GYY4137, significantly inhibited ISO-induced hypertrophy in cardiomyocytes, as evidenced by decreased cell size. GYY4137 effectively inhibited ISO-induced oxidative stress (DCF-DA) and mitigated mitochondrial dysfunction (MitoSOX Red and JC-1), whereas BM-112 failed to alleviate these effects. Changes in autophagic protein expressions were analyzed by Western blot, and LC3B/p62 colocalization was visualized with Lysotracker Red. We identified impaired autophagic flux in the presence of ISO and BM-112. However, GYY4137 treatment promoted autophagy beyond basal levels.Taken together, GYY4137, but not BM-112, successfully prevented adrenergic overstimulation-induced hypertrophy by reducing oxidative stress, mitigating mitochondrial dysfunction, and enhancing autophagic flux.