Hydrogen Sulfide Protects Human Cardiac Fibroblasts Against H 2 O 2 -induced Injury Through Regulating Autophagy-Related Proteins.

Autophagy, an intracellular bulk degradation process of proteins and organelles, can be induced by myocardial ischemia in the heart. However, the causative role of autophagy in the survival of human cardiac fibroblasts and the underlying mechanisms are incompletely understood. Oxidative stress can induce autophagy in cultured cells upon hydrogen peroxide (H2 O2 ) exposure. Because hydrogen sulfide (H2 S) regulates reactive oxygen species (ROS) and apoptosis, we hypothesize that H2 S may have a cardioprotective function. To examine our hypothesis, we investigated the regulation of autophagy by the H2 S donor sodium hydrosulfide (NaHS), using a cell model of human cardiac fibroblasts from adult ventricles (HCF-av) that suffered from endoplasmic reticulum (ER) stress by H2 O2 . In the present study, we found that the apoptosis and autophagy were induced along with ER stress by H2 O2 in the primary cultured HCF-av cells. In contrast, H2 S suppressed HCF-av cell apoptosis and autophagic flux, in part directly by inhibiting ROS production and preserving mitochondrial functions.