ABSTRACT
Emergent resistance to all clinical antibiotics calls for the next generation of therapeutics. Here we report an effective antimicrobial strategy targeting the bacterial hydrogen sulfide (H2S)-mediated defense system. We identified cystathionine γ-lyase (CSE) as the primary generator of H2S in two major human pathogens, Staphylococcus aureus and Pseudomonas aeruginosa, and discovered small molecules that inhibit bacterial CSE. These inhibitors potentiate bactericidal antibiotics against both pathogens in vitro and in mouse models of infection. CSE inhibitors also suppress bacterial tolerance, disrupting biofilm formation and substantially reducing the number of persister bacteria that survive antibiotic treatment. Our results establish bacterial H2S as a multifunctional defense factor and CSE as a drug target for versatile antibiotic enhancers.
Subject(s)
Anti-Bacterial Agents/pharmacology , Cystathionine gamma-Lyase/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Hydrogen Sulfide/metabolism , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/drug effects , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Biofilms , Crystallography, X-Ray , Cystathionine gamma-Lyase/chemistry , Cystathionine gamma-Lyase/genetics , Cystathionine gamma-Lyase/metabolism , Drug Discovery , Drug Resistance, Bacterial , Drug Synergism , Drug Tolerance , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/metabolism , Mice , Microbial Sensitivity Tests , Models, Molecular , Molecular Docking Simulation , Molecular Structure , Pseudomonas Infections/drug therapy , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/enzymology , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/growth & development , Small Molecule Libraries/chemistry , Small Molecule Libraries/metabolism , Small Molecule Libraries/pharmacology , Staphylococcal Infections/drug therapy , Staphylococcal Infections/microbiology , Staphylococcus aureus/enzymology , Staphylococcus aureus/genetics , Staphylococcus aureus/growth & developmentABSTRACT
The glycolytic rate in neurons is low in order to allow glucose to be metabolized through the pentose-phosphate pathway (PPP), which regenerates NADPH to preserve the glutathione redox status and survival. This is controlled by 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3), the pro-glycolytic enzyme that forms fructose-2,6-bisphosphate, a powerful allosteric activator of 6-phosphofructo-1-kinase. In neurons, PFKFB3 protein is physiologically inactive due to its proteasomal degradation. However, upon an excitotoxic stimuli, PFKFB3 becomes stabilized to activate glycolysis, thus hampering PPP mediated protection of redox status leading to neurodegeneration. Here, we show that selective inhibition of PFKFB3 activity by the small molecule AZ67 prevents the NADPH oxidation, redox stress and apoptotic cell death caused by the activation of glycolysis triggered upon excitotoxic and oxygen-glucose deprivation/reoxygenation models in mouse primary neurons. Furthermore, in vivo administration of AZ67 to mice significantly alleviated the motor discoordination and brain infarct injury in the middle carotid artery occlusion ischemia/reperfusion model. These results show that pharmacological inhibition of PFKFB3 is a suitable neuroprotective therapeutic strategy in excitotoxic-related disorders such as stroke.
