Hydrogen sulfide (H2S) is an endogenous signaling molecule which plays important roles in physiological functions of the cardiovascular system, but it’s mechanism of action is poorly understood. We have translated a common methodology to assess protein sulfenic acids to characterize and quantify endogenous hydrogen sulfide (H2S) and small oxoacids of sulfur (SOS = HOSH, HOSOH) in numerous cell lines and mammalian tissue samples. The method using nucleophilic and electrophilic traps for H-S and HO-S bonds to trap small molecular weight species, and allows quantification of these species giving both intra- and extra-cellular concentrations based on an H2S calibration curve. We compare the production of H2S and SOS across human, bacteria and yeast cell lines, as well in primary human human primary vascular cell lines: smooth muscle and endothelial cells derived from both human arterial and coronary tissues. H2S and its metabolites are orders of magnitude higher in smooth muscle (nanomolar) as compared to endothelial cell lines (picomolar) and yeast (femtomolar). We proposed the sulfomic index as a profile of non-protein S-oxide redox status. H2S and SOS were also found to be effluxed from smooth muscle cells in higher concentrations than endothelial cells in similar ratios. Human aortic smooth muscle cells were selected to examine changes in intracellular and efflux concentrations of H2S and SOS under hypoxic growth conditions. Under hypoxia, the smooth muscle cells demonstrated reduced mitochondrial respiration and increased ROS production, with a corresponding reduction in levels of H2S and HOSOH, but large increases in levels of HSOH, which we attribute to retrograde electron transfer to Complex 1 during hypoxia. We believe that measurements and characterizations these analytes under different disease states may help uncover the mechanisms of action attributed to H2S in cardiovascular health and disease. Several collaborators provided assistance and materials in this work and will be acknowledged in the presentation.

New HD LC MS methods of characterizing concentrations H2S and its oxidized metabolites in cell cultures.

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ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.