RESUMO
Blocking virulence is a promising alternative to counteract Pseudomonas aeruginosa infections. In this regard, the phenomenon of cell-cell communication by quorum sensing (QS) is an important anti-virulence target. In this field, fatty acids (FA) have gained notoriety for their role as autoinducers, as well as anti-virulence molecules in vitro, like some saturated FA (SAFA). In this study, we analyzed the anti-virulence activity of SAFA with 12 to18 carbon atoms and compared their effect with the putative autoinducer cis-2-decenoic acid (CDA). The effect of SAFA on six QS-regulated virulence factors and on the secretion of the exoenzyme ExoU was evaluated. In addition, a murine cutaneous infection model was used to determine their influence on the establishment and damage caused by P. aeruginosa PA14. Dodecanoic (lauric, C12:0) and tetradecanoic (myristic, C14:0) acids (SAFA C12-14) reduced the production of pyocyanin by 35-58% at 40 and 1,000 µM, while CDA inhibited it 62% at a 3.1 µM concentration. Moreover, the SAFA C12-14 reduced swarming by 90% without affecting biofilm formation. In contrast, CDA reduced the biofilm by 57% at 3 µM but did not affect swarming. Furthermore, lauric and myristic acids abolished ExoU secretion at 100 and 50 µM respectively, while CDA reduced it by ≈ 92% at 100 µM. Remarkably, the coadministration of myristic acid (200 and 1,000 µM) with P. aeruginosa PA14 induced greater damage and reduced survival of the animals up to 50%, whereas CDA to 500 µM reduced the damage without affecting the viability of the PA14 strain. Hence, our results show that SAFA C12-14 and CDA have a role in regulation of P. aeruginosa virulence, although their inhibition/activation molecular mechanisms are different in complex environments such as in vivo systems.
Assuntos
Infecções por Pseudomonas , Pseudomonas aeruginosa , Animais , Antibacterianos/farmacologia , Biofilmes , Camundongos , Ácidos Mirísticos/farmacologia , Percepção de Quorum , Virulência , Fatores de Virulência/farmacologiaRESUMO
The pathogenesis of the muscular symptoms and recurrent rhabdomyolysis that are commonly manifested in patients with mitochondrial trifunctional protein (MTP) and long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) deficiencies is still unknown. In this study we investigated the effects of the major long-chain monocarboxylic 3-hydroxylated fatty acids (LCHFA) accumulating in these disorders, namely 3-hydroxytetradecanoic (3HTA) and 3-hydroxypalmitic (3HPA) acids, on important mitochondrial functions in rat skeletal muscle mitochondria. 3HTA and 3HPA markedly increased resting (state 4) and decreased ADP-stimulated (state 3) and CCCP-stimulated (uncoupled) respiration. 3HPA provoked similar effects in permeabilized skeletal muscle fibers, validating the results obtained in purified mitochondria. Furthermore, 3HTA and 3HPA markedly diminished mitochondrial membrane potential, NAD(P)H content and Ca(2+) retention capacity in Ca(2+)-loaded mitochondria. Mitochondrial permeability transition (mPT) induction probably underlie these effects since they were totally prevented by cyclosporin A and ADP. In contrast, the dicarboxylic analogue of 3HTA did not alter the tested parameters. Our data strongly indicate that 3HTA and 3HPA behave as metabolic inhibitors, uncouplers of oxidative phosphorylation and mPT inducers in skeletal muscle. It is proposed that these pathomechanisms disrupting mitochondrial homeostasis may be involved in the muscle alterations characteristic of MTP and LCHAD deficiencies.
Assuntos
Cardiomiopatias/metabolismo , Erros Inatos do Metabolismo Lipídico/metabolismo , Mitocôndrias Musculares/efeitos dos fármacos , Miopatias Mitocondriais/metabolismo , Proteína Mitocondrial Trifuncional/deficiência , Ácidos Mirísticos/farmacologia , Doenças do Sistema Nervoso/metabolismo , Ácidos Palmíticos/farmacologia , Rabdomiólise/metabolismo , Animais , Cálcio/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias Musculares/metabolismo , Mitocôndrias Musculares/fisiologia , Proteína Mitocondrial Trifuncional/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , NADP/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Ratos WistarRESUMO
A synthetic mixture of an oviposition-stimulating kairomone for the yellow fever mosquito, Aedes aegypti, comprising of 83% tetradecanoic acid, 16% nonanoic acid and 1% tetradecanoic acid methyl ester (NTT, in short) was tested in a dengue endemic area in Recife, Brazil. Gravid female mosquitoes confined to a cage under semi-field conditions deposited significantly higher numbers of eggs in traps baited with NTT at doses ranging from 0.6 to 600 ng/microl than in control (water) traps. When tested in homes, egg-laying in traps baited with 60 ng NTT/microl (final concentration in trap, approximately 3.33 ng/ml) and in control traps was not significantly different, but egg deposited in traps with lower dosage (6 ng NTT/microl; final concentration in trap, approximately 0.33 ng/ml) was significantly higher than in control traps. In subsequent trials, the numbers of eggs laid in traps baited with 0.6 ng NTT/microl (final concentration in trap, approximately 0.033 ng/ml) were not significantly different from the numbers deposited in trap loaded with 6 ng NTT/microl. Egg-laying was significantly higher in these treatments than in control traps.
Assuntos
Aedes/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Feromônios/farmacologia , Febre Amarela/transmissão , Animais , Brasil , Ácidos Graxos/farmacologia , Feminino , Ácido Mirístico/farmacologia , Ácidos Mirísticos/farmacologiaRESUMO
AIMS: We investigated the in vitro effects of 3-hydroxydodecanoic (3HDA), 3-hydroxytetradecanoic (3HTA) and 3-hydroxypalmitic (3HPA) acids, which accumulate in tissues of patients affected by mitochondrial trifunctional protein (MTP) and isolated long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiencies, on various parameters of energy homeostasis in mitochondrial preparations from brain of young rats. MAIN METHODS: We measured the respiratory parameters state 4, state 3, respiratory control ratio (RCR) and ADP/O ratio by the rate of oxygen consumption, as well as the mitochondrial membrane potential and the matrix NAD(P)H levels in the presence of the fatty acids. KEY FINDINGS: We found that 3HDA, 3HTA and 3HPA markedly increased state 4 respiration and diminished the RCR using glutamate plus malate or succinate as substrates. 3HTA and 3HPA also diminished the mitochondrial membrane potential and the matrix NAD(P)H levels. In addition, 3HTA decreased state 3 respiration using glutamate/malate, but not pyruvate/malate or succinate as substrates. Our data indicate that the long-chain 3-hydroxy fatty acids that accumulate in LCHAD/MTP deficiencies act as uncouplers of oxidative phosphorylation, while 3HTA also behaves as a metabolic inhibitor. SIGNIFICANCE: It is presumed that impairment of brain energy homeostasis caused by these endogenous accumulating compounds may contribute at least in part to the neuropathology of LCHAD/MTP deficiencies.
Assuntos
3-Hidroxiacil-CoA Desidrogenases/deficiência , Encéfalo/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Ácidos Láuricos/farmacologia , Mitocôndrias/efeitos dos fármacos , Complexos Multienzimáticos/deficiência , Ácidos Mirísticos/farmacologia , 3-Hidroxiacil-CoA Desidrogenases/efeitos dos fármacos , 3-Hidroxiacil-CoA Desidrogenases/metabolismo , Animais , Encéfalo/metabolismo , Homeostase/efeitos dos fármacos , 3-Hidroxiacil-CoA Desidrogenase de Cadeia Longa , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteína Mitocondrial Trifuncional , Complexos Multienzimáticos/efeitos dos fármacos , Complexos Multienzimáticos/metabolismo , NADP/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
4-thiatetradecanoic acid exhibited weak antifungal activities against Candida albicans (ATCC 60193), Cryptococcus neoformans (ATCC 66031), and Aspergillus niger (ATCC 16404) (MIC=4.8-12.7 mM). It has been demonstrated that alpha-methoxylation efficiently blocks beta-oxidation and significantly improve the antifungal activities of fatty acids. We examined whether antifungal activity of 4-thiatetradecanoic acid can be improved by alpha-substitution. The unprecedented (+/-)-2-hydroxy-4-thiatetradecanoic acid was synthesized in four steps (20% overall yield), while the (+/-)-2-methoxy-4-thiatetradecanoic acid was synthesized in five steps (14% overall yield) starting from 1-decanethiol. The key step in the synthesis was the hydrolysis of a trimethylsilyloxynitrile. In general, the novel (+/-)-2-methoxy-4-thiatetradecanoic acid displayed significantly higher antifungal activities against C. albicans (ATCC 60193), C. neoformans (ATCC 66031), and A. niger (ATCC 16404) (MIC=0.8-1.2 mM), when compared with 4-thiatetradecanoic acid. In the case of C. neoformans the (+/-)-2-hydroxy-4-thiatetradecanoic acid was more fungitoxic (MIC=0.17 mM) than the alpha-methoxylated analog, but not as effective against A. niger (MIC=5.5 mM). The enhanced fungitoxicity of the (+/-)-2-methoxy-4-thiatetradecanoic acid, as compared to decylthiopropionic acid, might be the result of a longer half-life in the cells due to a blocked beta-oxidation pathway which results in more time to exert its toxic effects. Thus, these novel fatty acids may have applications as probes to study fatty acid metabolic routes in human cells.
Assuntos
Antifúngicos/síntese química , Ácidos Mirísticos/síntese química , Antifúngicos/farmacocinética , Antifúngicos/farmacologia , Aspergillus niger/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Linhagem Celular , Cryptococcus neoformans/efeitos dos fármacos , Meia-Vida , Humanos , Testes de Sensibilidade Microbiana , Ácidos Mirísticos/farmacocinética , Ácidos Mirísticos/farmacologia , Relação Estrutura-AtividadeRESUMO
The marine fatty acid (+/-)-2-methoxytetradecanoic acid was synthesized in two steps (71% overall yield) starting from commercially available methyl-2-hydroxy-tetradecanoate. The title compound was antifungal against Candida albicans (ATCC 14053) in RPMI medium and Aspergillus niger (ATCC 16404) and Cryptococcus neoformans (ATCC 66031) in SDB medium at the minimum inhibitory concentration (MIC) of 100 mM, which compares to the fungitoxicity of a 2-iodotetradecanoic acid against the same fungi. The title compound was also five to ten times more cytotoxic than capric acid to C. albicans and A. niger in the tested medium but comparable in cytotoxicity to either capric acid and its 2-methoxylated analog to C. neoformans. The antifungal activity of (+/-)-2-methoxytetradecanoic acid is explained in terms of inhibition of N-myristoyltransferase.
Assuntos
Antifúngicos/síntese química , Antifúngicos/farmacologia , Miristatos/síntese química , Miristatos/farmacologia , Ácidos Mirísticos/síntese química , Ácidos Mirísticos/farmacologia , Aciltransferases/antagonistas & inibidores , Aciltransferases/biossíntese , Aciltransferases/farmacocinética , Anfotericina B/farmacologia , Aspergillus niger/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Ácidos Graxos/síntese química , Técnicas In VitroRESUMO
The effects of two myristic acid analogs on Junin virus (JV) replication were investigated. The compounds chosen for the study were DL-2-hydroxymyristic acid (2OHM), an inhibitor of N-myristoyltransferase (NMT), which binds the enzyme and blocks protein myristoylation, and 13-oxamyristic acid (13OM), a competitive inhibitor of NMT which incorporates into the protein instead of myristic acid. Both types of analogs achieved dose-dependent inhibition of viral multiplication at concentrations not affecting cell viability. The 50% inhibitory concentration values determined by a virus-yield inhibition assay for different strains of JV, including a human pathogenic strain, and for the related arenavirus, Tacaribe, were in the range 1.6 to 20.1 microM, with 13OM as the most active compound. From time of addition and removal experiments, it can be concluded that both analogs inhibit a late stage in the JV replicative cycle, and their effect was partially reversible. The cytoplasmic and surface expression of JV glycoproteins was not affected in the presence of the compounds, as revealed by immunofluorescence staining, suggesting that JV glycoprotein myristoylation would not be essential for the intracellular transport of the envelope proteins, but it may have an important role in their interaction with the plasma membrane during virus budding.
Assuntos
Antivirais/farmacologia , Vírus Junin/efeitos dos fármacos , Miristatos/farmacologia , Replicação Viral/efeitos dos fármacos , Aciltransferases/antagonistas & inibidores , Aciltransferases/metabolismo , Animais , Antígenos Virais/biossíntese , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Vírus Junin/enzimologia , Vírus Junin/metabolismo , Vírus Junin/fisiologia , Lauratos/farmacologia , Miristatos/metabolismo , Ácidos Mirísticos/farmacologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Fatores de Tempo , Células Vero , Proteínas Virais/biossínteseRESUMO
Three new cytotoxic compounds, one a cyclic-peroxide-containing acid (5) and the two others alkylated dihydroxy alpha,beta-unsaturated C22 and C21 acids (6 and 7), were isolated from the marine sponge Plakortis halichondrioides, which was collected off the coast of Jamaica. The structures were elucidated through mass and mainly 1D and 2D nmr spectral analysis. All three acids are cytotoxic against P-388 murine leukemia.