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Antiviral Research Oct 2021Human cytomegalovirus (HCMV) is a near ubiquitous herpesvirus that relies on host cell metabolism for efficient replication. Although it has been shown that HCMV...
Human cytomegalovirus (HCMV) is a near ubiquitous herpesvirus that relies on host cell metabolism for efficient replication. Although it has been shown that HCMV requires functional host cell mitochondria for efficient replication, it is unknown whether mitochondrial targeted pharmacological agents can be repurposed as antivirals. Here we report that treatment with drugs targeting the electron transport chain (ETC) complexes inhibit HCMV replication. Addition of rotenone, oligomycin, antimycin and metformin resulted in decreased HCMV titers in vitro, independent of HCMV strain. This further illustrates the dependence of HCMV replication on functional mitochondria. Metformin, an FDA approved drug, delays HCMV replication kinetics resulting in a reduction of viral titers. Repurposing metformin as an antiviral is advantageous as its safety profile and epidemiological data are well accepted. Our findings provide new insight into the potential for targeting HCMV infection through host cell metabolism and how these pharmacological interventions function.
Topics: Antiviral Agents; Cells, Cultured; Cytomegalovirus; Electron Transport; Fibroblasts; Foreskin; Humans; Male; Metformin; Oligomycins; Virus Replication
PubMed: 34390771
DOI: 10.1016/j.antiviral.2021.105159 -
PLoS Pathogens Mar 2020Biofilm-associated prosthetic joint infections (PJIs) cause significant morbidity due to their recalcitrance to immune-mediated clearance and antibiotics, with...
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
PubMed: 32142554
DOI: 10.1371/journal.ppat.1008354 -
Cellular Physiology and Biochemistry :... 2012Although the precise mechanisms involved in intestinal barrier dysfunction induced by proinflammatory cytokines are incompletely understood, pharmacological restoration...
Although the precise mechanisms involved in intestinal barrier dysfunction induced by proinflammatory cytokines are incompletely understood, pharmacological restoration of barrier function is very important to the management of intestinal disease. This study was aimed to investigate the protective role of HIF-1α inhibitor oligomycin against intestinal epithelial barrier dysfunction induced by proinflammatory cytokines IFN-γ and TNF-α, and the underlying mechanisms. To induce barrier dysfunction, Caco-2 monolayers were treated with IFN-γ and TNF-α simultaneously. The cytokines-treated Caco-2 monolayers in the absence and in the presence of oligomycin were used for physiological, morphological, and biochemical analyses. The results showed that at the concentration of blocking HIF-1α activation, oligomycin significantly ameliorated TER reduction and paracellular permeability increase in Caco-2 monolayers challenged with IFN-γ and TNF-α. Oligomycin also largely attenuated the IFN-γ and TNF-α-related relocalization of tight junction proteins ZO-1 and occludin. Western blot analysis revealed that oligomycin abolished the increases of both MLC phosphorylation and MLCK protein expression induced by IFN-γ and TNF-α challenge. Quantitative RT-PCR analysis showed that oligomycin inhibited the IFN-γ and TNF-α-induced up-regulation of MLCK mRNA. It is concluded that oligomycin is able to attenuate intestinal epithelial barrier dysfunction induced by proinflammatory cytokines IFN-γ and TNF-α. The mechanism by which oligomycin protects intestinal barrier function may, at least in part, be attributed to block the up-regulated MLCK transcription and protein expression induced by IFN-γ and TNF-α.
Topics: Base Sequence; Blotting, Western; Caco-2 Cells; DNA Primers; Fluorescent Antibody Technique; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Interferon-gamma; Intestinal Mucosa; Myosin Light Chains; Myosin-Light-Chain Kinase; Oligomycins; Phosphorylation; Real-Time Polymerase Chain Reaction; Tumor Necrosis Factor-alpha
PubMed: 22613980
DOI: 10.1159/000188076 -
Science (New York, N.Y.) May 2018Mitochondrial adenosine triphosphate (ATP) synthase comprises a membrane embedded F motor that rotates to drive ATP synthesis in the F subunit. We used single-particle...
Mitochondrial adenosine triphosphate (ATP) synthase comprises a membrane embedded F motor that rotates to drive ATP synthesis in the F subunit. We used single-particle cryo-electron microscopy (cryo-EM) to obtain structures of the full complex in a lipid bilayer in the absence or presence of the inhibitor oligomycin at 3.6- and 3.8-angstrom resolution, respectively. To limit conformational heterogeneity, we locked the rotor in a single conformation by fusing the F6 subunit of the stator with the δ subunit of the rotor. Assembly of the enzyme with the F6-δ fusion caused a twisting of the rotor and a 9° rotation of the F c-ring in the direction of ATP synthesis, relative to the structure of isolated F Our cryo-EM structures show how F and F are coupled, give insight into the proton translocation pathway, and show how oligomycin blocks ATP synthesis.
Topics: Adenosine Triphosphate; Cryoelectron Microscopy; Membrane Lipids; Mitochondrial Membranes; Mitochondrial Proton-Translocating ATPases; Molecular Motor Proteins; Oligomycins; Protein Conformation; Protein Subunits; Saccharomyces cerevisiae Proteins; Single Molecule Imaging
PubMed: 29650704
DOI: 10.1126/science.aas9699 -
Scientific Reports Oct 2020Dendritic spine injury underlies synaptic failure in many neurological disorders. Mounting evidence suggests a mitochondrial pathway of local nonapoptotic caspase...
Dendritic spine injury underlies synaptic failure in many neurological disorders. Mounting evidence suggests a mitochondrial pathway of local nonapoptotic caspase signaling in mediating spine pruning. However, it remains unclear whether this caspase signaling plays a key role in spine loss when severe mitochondrial functional defects are present. The answer to this question is critical especially for some pathological states, in which mitochondrial deficits are prominent and difficult to fix. F1Fo ATP synthase is a pivotal mitochondrial enzyme and the dysfunction of this enzyme involves in diseases with spinopathy. Here, we inhibited F1Fo ATP synthase function in primary cultured hippocampal neurons by using non-lethal oligomycin A treatment. Oligomycin A induced mitochondrial defects including collapsed mitochondrial membrane potential, dissipated ATP production, and elevated reactive oxygen species (ROS) production. In addition, dendritic mitochondria underwent increased fragmentation and reduced positioning to dendritic spines along with increased caspase 3 cleavage in dendritic shaft and spines in response to oligomycin A. Concurring with these dendritic mitochondrial changes, oligomycin A-insulted neurons displayed spine loss and altered spine architecture. Such oligomycin A-mediated changes in dendritic spines were substantially prevented by the inhibition of caspase activation by using a pan-caspase inhibitor, quinolyl-valyl-O-methylaspartyl-[-2,6-difluorophenoxy]-methyl ketone (Q-VD-OPh). Of note, the administration of Q-VD-OPh showed no protective effect on oligomycin A-induced mitochondrial dysfunction. Our findings suggest a pivotal role of caspase 3 signaling in mediating spine injury and the modulation of caspase 3 activation may benefit neurons from spine loss in diseases, at least, in those with F1Fo ATP synthase defects.
Topics: Adenosine Triphosphate; Amino Acid Chloromethyl Ketones; Animals; Caspase 3; Caspase Inhibitors; Cell Death; Dendritic Spines; Female; Hippocampus; Male; Membrane Potential, Mitochondrial; Mice; Mice, Inbred C57BL; Mitochondria; Mitochondrial Proton-Translocating ATPases; Neurons; Oligomycins; Quinolines; Reactive Oxygen Species
PubMed: 33067541
DOI: 10.1038/s41598-020-74613-9 -
Journal of Global Antimicrobial... Sep 2020The aim of this study was to obtain Streptomyces xinghaiensis (fradiae) ATCC 19609 mutants resistant to oligomycin A and its derivatives and to identify the underlying...
OBJECTIVES
The aim of this study was to obtain Streptomyces xinghaiensis (fradiae) ATCC 19609 mutants resistant to oligomycin A and its derivatives and to identify the underlying mechanism of resistance. This study was based on the premise that S. xinghaiensis ATCC 19609 contains several oligomycin A biological targets, explaining why the strain remains supersensitive to oligomycin A despite all efforts to obtain resistant mutants using standard genetic methods.
METHODS
The method to obtain oligomycin A-resistant mutants was performed in two steps: first, mutants slightly resistant to an oligomycin A derivative with an attenuated effect were obtained; and second, oligomycin A-resistant mutants were obtained from those mutants obtained earlier. The genomes of the mutants were then sequenced and a bioinformatics analysis of the detected mutations was conducted.
RESULTS
Mutants with seven mutations were required to obtain oligomycin A-resistant mutant strains of S. xinghaiensis characterised by a level of resistance comparable with that of the model organism Streptomyces lividans. Five of these mutations caused amino acid substitutions in the well-known oligomycin A biological target, namely the F0F1-ATP synthase A subunit, and the others caused amino acid substitutions in unexplored biological targets, including RecB-like recombinase, type IV helicase, DNA ligase and single-domain response regulator.
CONCLUSION
A new oligomycin resistance mechanism involving a pathway that repairs double-strand breaks in DNA known as non-homologous end joining (NHEJ) was discovered.
Topics: Computational Biology; Drug Resistance, Bacterial; Mutation; Oligomycins; Streptomyces
PubMed: 32061812
DOI: 10.1016/j.jgar.2020.01.026 -
International Journal of Molecular... Sep 2022Platelets produce inorganic polyphosphate (polyP) upon activation to stimulate blood coagulation. Some researchers have linked polyP metabolism to ATP production,...
Platelets produce inorganic polyphosphate (polyP) upon activation to stimulate blood coagulation. Some researchers have linked polyP metabolism to ATP production, although the metabolic linkage is yet to be elucidated. We found evidence for this possibility in our previous study on professional athletes (versus non-athletes), and proposed that the regulatory mechanism might be different for these two groups. To explore this aspect further, we investigated the effects of modulated ATP production on polyP levels. Blood samples were obtained from Japanese healthy, non-athletes in the presence of acid-citrate-dextrose. The platelets in the plasma were treated with oligomycin, rotenone, and GlutaMAX to modulate ATP production. PolyP level was quantified fluorometrically and visualized using 4',6-diamidino-2-phenylindole. Correlations between polyP and ATP or NADH were then calculated. Contrary to the hypothesis, inhibitors of ATP production increased polyP levels, whereas amino acid supplementation produced the opposite effect. In general, however, polyP levels were positively correlated with ATP levels and negatively correlated with NADH levels. Since platelets are metabolically active, they exhibit high levels of ATP turnover rate. Therefore, these findings suggest that ATP may be involved in polyP production in the resting platelets of non-athletes.
Topics: Adenosine Triphosphate; Amino Acids; Citrates; Glucose; Humans; NAD; Oligomycins; Polyphosphates; Rotenone
PubMed: 36232597
DOI: 10.3390/ijms231911293 -
Journal of Cerebral Blood Flow and... Jan 2017Cerebral edema represents a major threat following traumatic brain injury. However, therapeutic measures for control of intracranial pressure alone have failed to...
Cerebral edema represents a major threat following traumatic brain injury. However, therapeutic measures for control of intracranial pressure alone have failed to restore cerebral metabolism and improve neurological outcome. Since mitochondrial damage results in ATP depletion and deactivation of membrane ionic pumps, we hypothesized that modulation of ATP bioavailability may directly affect cytotoxic edema. Intracranial pressure measurements were performed in Sprague-Dawley rats treated by intraperitoneal injection of dimethylsulfoxide (vehicle), cyclosporine A (CsA), or Oligomycin B (OligB) following cortical contusion and further correlated with water content, mitochondrial damage, and electron microscopic assessment of neuronal and axonal edema. As hypothesized, ultra-structural figures of edema closely correlated with intracranial pressure elevation, increased water content and mitochondrial membrane permeabilization expressed by loss of transmembrane mitochondrial potential. Further, mitochondrial damage evidenced ultra-structurally by figures of swollen mitochondria with severely distorted cristae correlated with both cytotoxic edema and mitochondrial dysfunction. Importantly, cerebral edema and mitochondrial impairment were significantly worsened by treatment with OligB, whereas a noticeable improvement could be observed in animals that received injections of CsA. Since OligB and CsA are responsible for symmetrical and opposite effects on oxidative metabolism, these findings support the hypothesis of a causative relationship between edema and mitochondrial function.
Topics: Animals; Brain Edema; Brain Injuries, Traumatic; Cyclosporine; Intracranial Pressure; Mitochondria; Mitochondrial Membranes; Oligomycins; Rats; Rats, Sprague-Dawley
PubMed: 26672111
DOI: 10.1177/0271678X15621068 -
European Journal of Biochemistry Sep 19801. Oligomycin and dicyclohexylcarbodiimide-sensitive ATPase was isolated from beef-heart mitochondria and treated with 3.5 M NaBr in order to remove F1. The residue,...
1. Oligomycin and dicyclohexylcarbodiimide-sensitive ATPase was isolated from beef-heart mitochondria and treated with 3.5 M NaBr in order to remove F1. The residue, called F0, was found to consist of seven components. Five of these are stained by Coomassie blue after dodecylsulfate-polyacrylamide-gel electrophoresis. Two of them correspond to the oligomycin-sensitivity-conferring protein and coupling factor F6, with apparent molecular weights of 21,000 and 9,400, respectively. Three additional polypeptides of molecular weights 23,000, 10,500 and 8,600 were not identified with known proteins. Two components not stained with Coomassie blue were detected by autoradiography of the gels of F0 preincubated with [14C]dicyclohexylcarbodiimide. These two components probably represent monomeric and oligomeric forms of the dicyclohexylcarbodiimide-binding protein. 2. F0 induced an oligomycin and dicyclohexylcarbodiimide-sensitive enhancement of K+ + valinomycin-driven proton translocation across the membrane of artificial phospholipid vesicles. 3. The interaction of F0 with purified, soluble beef heart F1 was investigated. F0 was capable of binding F1 and conferring oligomycin and dicyclohexylcarbodiimide sensitivity and cold stability on its ATPase activity. Furthermore F0 was found to diminish the specific activity of F1-ATPase. A comparison of these effects at varying F0/F1 ratios shows that F0 binds F1 in both an oligomycin-sensitive and an oligomycin-insensitive manner, and that both types of binding involve a conferral of cold stability and a decrease in specific activity. High F0/F1 ratios favoured in oligomycin-sensitive type of binding, indicating that F1 binds preferentially to oligomycin-sensitivity-conferring sites. Treatment of ATPase complex with trypsin resulted in an F0 with a decreased proportion of oligomycin-sensitivity-conferring binding sites and a diminished ability to lower the specific activity an cold lability of F1. 4. Reconstitution of F0 treated with trypsin and F1, oligomycin-sensitivity-conferring protein and F6 showed that at a constant amount of F1 bound, both oligomycin-sensitivity-conferring protein and F6 increased the oligomycin sensitivity of ATPase activity. It was therefore concluded that both of these coupling factors are involved in the conferral of oligomycin sensitivity. 5. The effect of the order of addition of F1, oligomycin-sensitivity-conferring protein and F6 to F0 on the reconstitution of oligomycin-sensitive ATPase activity, and of F1 and oligomycin-sensitivity-conferring protein to submitochondrial particles on the reconstitution of respiratory control, was investigated. The highest values of oligomycin sensitivity and respiratory control were obtained when F1 was added as the first component, indicating that F1 plays a directing role in the organisation of the components.
Topics: Adenosine Triphosphatases; Animals; Bromides; Carbodiimides; Carrier Proteins; Cattle; Dicyclohexylcarbodiimide; Liposomes; Macromolecular Substances; Membrane Proteins; Mitochondria, Heart; Mitochondrial Proton-Translocating ATPases; Molecular Weight; Oligomycins; Oxidative Phosphorylation Coupling Factors; Proton-Translocating ATPases; Protons; Sodium; Sodium Compounds
PubMed: 6108210
DOI: 10.1111/j.1432-1033.1980.tb04859.x -
EMBO Reports May 2014Larvae of Drosophila melanogaster reared at 23°C and switched to 14°C for 1 h are 0.5°C warmer than the surrounding medium. In keeping with dissipation of energy,...
Larvae of Drosophila melanogaster reared at 23°C and switched to 14°C for 1 h are 0.5°C warmer than the surrounding medium. In keeping with dissipation of energy, respiration of Drosophila melanogaster larvae cannot be decreased by the F-ATPase inhibitor oligomycin or stimulated by protonophore. Silencing of Ucp4C conferred sensitivity of respiration to oligomycin and uncoupler, and prevented larva-to-adult progression at 15°C but not 23°C. Uncoupled respiration of larval mitochondria required palmitate, was dependent on Ucp4C and was inhibited by guanosine diphosphate. UCP4C is required for development through the prepupal stages at low temperatures and may be an uncoupling protein.
Topics: Animals; Cells, Cultured; Cold Temperature; Drosophila Proteins; Drosophila melanogaster; Enzyme Inhibitors; Gene Knockout Techniques; Guanosine Diphosphate; Larva; Membrane Transport Proteins; Mitochondria; Oligomycins; Oxygen Consumption; Palmitates; Respiration; Thermogenesis; Uncoupling Agents
PubMed: 24639557
DOI: 10.1002/embr.201337972