Subcellular Delivery of Hydrogen Sulfide Using Small Molecule Donors Impacts Organelle Stress

Hydrogen sulfide (H2S) is an endogenously produced gaseous signaling molecule with important roles in regulating organelle function and stress. Because of its high reactivity, targeted delivery of H2S using small molecule H2S donors has garnered significant interest to minimize off-target effects. Although mitochondrially targeted H2S donors, such as AP39, have been reported previously and exhibit significantly higher potency than nontargeted donors, the expansion of targeted H2S delivery to other subcellular organelles remains largely absent. To fill this key unmet need, we report a library of organelle-targeted H2S donors that localize H2S delivery to specific subcellular organelles, including the Golgi apparatus, lysosome, endoplasmic reticulum, and mitochondria. We measured H2S production in vitro from each donor, confirmed the localization of H2S delivery using organelle-specific H2S responsive fluorescent probes, and demonstrated enhanced potency of these targeted H2S donors in providing protection against organelle-specific stress. We anticipate this class of targeted H2S donors will enable future studies of subcellular roles of H2S and the pathways by which H2S alleviates subcellular organelle stress.