oligomycins and Inflammation

Biofilm-associated prosthetic joint infections (PJIs) cause significant morbidity due to their recalcitrance to immune-mediated clearance and antibiotics, with Staphylococcus aureus (S. aureus) among the most prevalent pathogens. We previously demonstrated that S. aureus biofilm-associated monocytes are polarized to an anti-inflammatory phenotype and the adoptive transfer of pro-inflammatory macrophages attenuated biofilm burden, highlighting the critical role of monocyte/macrophage inflammatory status in dictating biofilm persistence. The inflammatory properties of leukocytes are linked to their metabolic state, and here we demonstrate that biofilm-associated monocytes exhibit a metabolic bias favoring oxidative phosphorylation (OxPhos) and less aerobic glycolysis to facilitate their anti-inflammatory activity and biofilm persistence. To shift monocyte metabolism in vivo and reprogram cells to a pro-inflammatory state, a nanoparticle approach was utilized to deliver the OxPhos inhibitor oligomycin to monocytes. Using a mouse model of S. aureus PJI, oligomycin nanoparticles were preferentially internalized by monocytes, which significantly reduced S. aureus biofilm burden by altering metabolism and promoting the pro-inflammatory properties of infiltrating monocytes as revealed by metabolomics and RT-qPCR, respectively. Injection of oligomycin alone had no effect on monocyte metabolism or biofilm burden, establishing that intracellular delivery of oligomycin is required to reprogram monocyte metabolic activity and that oligomycin lacks antibacterial activity against S. aureus biofilms. Remarkably, monocyte metabolic reprogramming with oligomycin nanoparticles was effective at clearing established biofilms in combination with systemic antibiotics. These findings suggest that metabolic reprogramming of biofilm-associated monocytes may represent a novel therapeutic approach for PJI.

Topics: Animals; Biofilms; Cellular Reprogramming; Implants, Experimental; Inflammation; Mice; Monocytes; Oligomycins; Oxidative Phosphorylation; Staphylococcal Infections; Staphylococcus aureus

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Brain Ischemia; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Hippocampus; Humans; Inflammation; Lipopolysaccharides; Mice; Microglia; Neuroprotective Agents; Oligomycins; Oxidative Stress; Oxidopamine; Parkinsonian Disorders; Plant Preparations; Rats; Rotenone; Tissue Culture Techniques

In RA, synoviocytes cause increased oxidative stress, leading to mitochondrial alterations that may participate in the pathogenesis of RA. Here we investigated whether mitochondrial dysfunction induces inflammatory responses in cultured normal human synoviocytes, a hallmark of RA.. Mitochondrial dysfunction was induced with the inhibitor oligomycin. The effects of mitochondrial dysfunction on cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2) and IL-8 expression; cellular and mitochondrial reactive oxygen species (ROS) production; nuclear factor-κB (NF-κB) activation and p65 translocation were studied. ROS scavengers (N-acetylcysteine and mitoTEMPO) and an NF-κB inhibitor (BAY-117085) were used to investigate the pathways involved. The natural anti-inflammatory antioxidant resveratrol was also tested.. Mitochondrial dysfunction per se significantly stimulated mitochondrial ROS production as well as low-grade expressions of COX-2, PGE2 and IL-8. Interestingly, mitochondrial dysfunction induced by pretreatment of synoviocytes with oligomycin synergized with IL-1β to increase the expression of these inflammatory mediators. The inflammatory effects of mitochondrial damage appeared to be dependent on ROS production and NF-κB activation since the inflammatory response was counteracted by both N-acetylcysteine and mitoTEMPO and it was also reduced by BAY-117085. Antimycin A and paraquat (inhibitors of mitochondrial function) also induced inflammatory responses. Furthermore, resveratrol significantly reduced the inflammatory response by decreasing ROS production and NF-κB activation.. These data suggest that mitochondrial dysfunction could induce an inflammatory response in normal human synoviocytes and sensitize these cells, causing a significant amplification of the inflammatory response induced by IL-1β. Resveratrol may represent a promising strategy in controlling the synovial inflammatory response.

Topics: Aged; Arthritis, Rheumatoid; Cells, Cultured; Cyclooxygenase 2; Dinoprostone; Enzyme Inhibitors; Humans; Inflammation; Interleukin-1beta; Interleukin-8; Middle Aged; Mitochondria; NF-kappa B; Oligomycins; Oxidative Stress; Reactive Oxygen Species; Resveratrol; Stilbenes; Synovial Membrane

Adjuvant formulations boost humoral responses by acting through several, yet incompletely elucidated pathways. In this study, we show that oligomycin or 5-aminoimidazole-4-carboxamide-1-β-D-ribonucleoside (AICAR) enhances Ab production when coinjected with T cell-dependent Ags. Oligomycin and AICAR lead to intracellular ATP reduction, suggesting that metabolic stress could be sensed by immune cells and leads to increased humoral responses. AICAR promotes IL-4 and IL-21 by naive Th cells but does not affect dendritic cell activation/maturation in vitro or in vivo. Accordingly, the adjuvant effect of AICAR or oligomycin does not require MyD88 or caspase-1 expression in vivo. Because AICAR is well tolerated in humans, this compound could represent a novel and safe adjuvant promoting humoral responses in vivo with a minimal reactogenicity.

Topics: Adenosine Triphosphate; Adjuvants, Immunologic; Aminoimidazole Carboxamide; Animals; Carrier Proteins; Cells, Cultured; Immunoglobulin G; Inflammasomes; Inflammation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; NLR Family, Pyrin Domain-Containing 3 Protein; Oligomycins; Ribonucleotides; Stress, Physiological; Up-Regulation

In pathological situations, different modes of cell death are observed, and information on the role and uptake of nonapoptotic corpses is scarce. Here, we modeled two distinct forms of death in human Jurkat T cells treated with staurosporine: classical apoptosis under normal culture conditions and programmed death with necrotic morphology under ATP-depleting conditions (necPCD). When offered to phagocytes, both types of cell corpses (but not heat-killed unscheduled necrotic cells) reduced the release of the proinflammatory cytokine TNF from the macrophages. The necPCD cells were efficiently engulfed by macrophages and microglia, and from mixtures of necPCD and apoptotic cells macrophages preferentially engulfed the necrotic cells. Using a newly developed assay, we demonstrated that phosphatidylserine is translocated to the surface of such necrotic cells. We demonstrate that this can occur independently of calcium signals, and that surface phosphatidylserine is essential for the uptake of necrotic cells by both human macrophages and murine microglia.

Topics: Animals; Annexin A5; Antibodies, Monoclonal; Apoptosis; Calcium; CD36 Antigens; Cell Line; Cell Membrane; Cells, Cultured; Escherichia coli; Formaldehyde; Humans; Inflammation; Ionomycin; Jumonji Domain-Containing Histone Demethylases; Jurkat Cells; Lipopolysaccharide Receptors; Liposomes; Macrophages; Membrane Lipids; Mice; Microglia; Microscopy, Confocal; Microscopy, Fluorescence; Necrosis; Oligomycins; Oligopeptides; Phagocytosis; Phosphatidylserines; Polymers; Receptors, Cell Surface; Staurosporine; Tumor Necrosis Factor-alpha