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Diessl, J.

Publications and source records attributed to Diessl, J..

2 recordsLinked to original sources

Hydrogen sulfide dynamically upregulates copper uptake and localization

The reactivity of copper, an essential micronutrient that undergoes facile cycling between Cu1+ and Cu2+ redox states, is carefully controlled within the confines of protein binding sites, and by sequestration in storage vesicles, or harnessed to kill pathogens by active pumping of Cu1+ into phagosomes. We have discovered that hydrogen sulfide, a signaling metabolite generated in copious quantities at the host-microbiome interface, upregulates Cu accumulation in diffusely dispersed puncta across the cell, as visualized by X-ray fluorescence microscopy. The Cu is predominantly in the Cu2+ state with oxygen/nitrogen ligands. Cu import occurs via the non- canonical ZNT1 transporter, while export, following sulfide withdrawal, is ATP7A-dependent. Cu accumulates at the apices of colon crypts in a mouse model of elevated sulfide exposure due to SQOR deficiency in the intestinal epithelium, establishing in vivo relevance. Our study reveals that sulfide is a dynamic regulator of the Cu pool, stimulating Cu2+ influx into highly concentrated puncta.

cell biology↗

H2S preconditioning induces long-lived perturbations in O2 metabolism

Hydrogen sulfide exposure in moderate doses can induce profound but reversible hypometabolism in mammals. At a cellular level, H2S inhibits the electron transport chain (ETC), augments aerobic glycolysis, and glutamine-dependent carbon utilization via reductive carboxylation; however, the durability of these changes is unknown. We report that despite its volatility, H2S preconditioning increases P50(O2), the O2 pressure for half maximal cellular respiration, and has pleiotropic effects on oxidative metabolism that persist up to 24-48 h later. Notably, cyanide, another complex IV inhibitor, does not induce this type of metabolic memory. Sulfide-mediated prolonged fractional inhibition of complex IV by H2S is modulated by sulfide quinone oxidoreductase, which commits sulfide to oxidative catabolism. Since induced hypometabolism can be beneficial in disease settings that involve insufficient or interrupted blood flow, our study has important implications for attenuating reperfusion-induced ischemic injury, and/or prolonging shelf life of biologics like platelets.

biochemistry↗