RESUMO
The essential oil from Rosmarinus officinalis L., a composite mixture of plant-derived secondary metabolites, exhibits antifungal activity against virulent candidal species. Here we report the impact of rosemary oil and two of its components, the monoterpene α-pinene and the monoterpenoid 1,8-cineole, against Candida albicans, which induce ROS-dependent cell death at high concentrations and inhibit hyphal morphogenesis and biofilm formation at lower concentrations. The minimum inhibitory concentrations (100% inhibition) for both rosemary oil and 1,8-cineole were 4500 µg/ml and 3125 µg/ml for α-pinene, with the two components exhibiting partial synergy (FICI = 0.55 ± 0.07). At MIC and 1/2 MIC, rosemary oil and its components induced a generalized cell wall stress response, causing damage to cellular and organelle membranes, along with elevated chitin production and increased cell surface adhesion and elasticity, leading to complete vacuolar segregation, mitochondrial depolarization, elevated reactive oxygen species, microtubule dysfunction, and cell cycle arrest mainly at the G1/S phase, consequently triggering cell death. Interestingly, the same oils at lower fractional MIC (1/8-1/4) inhibited virulence traits, including reduction of mycelium (up to 2-fold) and biofilm (up to 4-fold) formation, through a ROS-independent mechanism.
Assuntos
Óleos Voláteis , Rosmarinus , Eucaliptol/farmacologia , Candida albicans , Espécies Reativas de Oxigênio , Virulência , Óleos Voláteis/farmacologia , Testes de Sensibilidade Microbiana , Antifúngicos/farmacologia , Monoterpenos/farmacologiaRESUMO
Microbes have an arsenal of virulence factors that contribute to their pathogenicity. A number of challenges remain to fully understand disease transmission, fitness landscape, antimicrobial resistance and host heterogeneity. A variety of tools have been used to address diverse aspects of pathogenicity, from molecular host-pathogen interactions to the mechanisms of disease acquisition and transmission. Current gaps in our knowledge include a more direct understanding of host-pathogen interactions, including signaling at interfaces, and direct phenotypic confirmation of pathogenicity. Correlative microscopy has been gaining traction to address the many challenges currently faced in biomedicine, in particular the combination of optical and atomic force microscopy (AFM). AFM, generates high-resolution surface topographical images, and quantifies mechanical properties at the pN scale under physiologically relevant conditions. When combined with optical microscopy, AFM probes pathogen surfaces and their physical and molecular interaction with host cells, while the various modes of optical microscopy view internal cellular responses of the pathogen and host. Here we review the most recent advances in our understanding of pathogens, recent applications of AFM to the field, how correlative AFM-optical microspectroscopy and microscopy have been used to illuminate pathogenicity and how these methods can reach their full potential for studying host-pathogen interactions.
Assuntos
Interações Hospedeiro-Patógeno , Humanos , Microscopia de Força AtômicaRESUMO
Macromolecules of vitellogenin were sequestered by Xenopus laevis oocytes 20-50 times (on a molar basis) more rapidly than other proteins tested. Selectivity for vitellogenin did not appear to involve molecular size or charge. The Km for vitellogenin incorporation was at least several orders of magnitude less than that for bovine serum albumin (BSA). At concentrations less than 10 mg-ml-1, BSA did not measurably compete with vitellogenin; a slight, apparent competition observed above a BSA concentration of 10 mg-ml-1 was probably spurious. Above a concentration of 2 mg-ml-1, vitellogenin promoted BSA incorporation by about 40%. These results are consistent with the notion that vitellogenin binds to specific receptor sites on the oocyte membrane and is subsequently internalized by micropinocytosis. Other proteins, such as BSA, which do not compete with vitellogenin are most likely to be incorporated by adventitious engulfment during micropinocytosis.
Assuntos
Lipoproteínas/metabolismo , Oócitos/metabolismo , Óvulo/metabolismo , Vitelogeninas/metabolismo , Animais , Feminino , Proteínas/metabolismo , Soroalbumina Bovina/farmacologia , XenopusAssuntos
Cálcio/farmacologia , Folículo Ovariano/metabolismo , Óvulo/metabolismo , Proteínas/metabolismo , Animais , Autorradiografia , Transporte Biológico , Proteínas Sanguíneas/metabolismo , Radioisótopos de Carbono , Ácido Edético/farmacologia , Estradiol , Feminino , Histocitoquímica , Marcação por Isótopo , Folículo Ovariano/citologia , Folículo Ovariano/efeitos dos fármacos , Óvulo/citologia , Óvulo/efeitos dos fármacos , Fatores de Tempo , Trítio , XenopusAssuntos
Proteínas do Ovo/metabolismo , Óvulo/metabolismo , Xenopus/embriologia , Animais , Centrifugação com Gradiente de Concentração , Proteínas do Ovo/biossíntese , Feminino , Complexo de Golgi/metabolismo , Técnicas In Vitro , Leucina , Membranas/metabolismo , Microscopia Eletrônica , Mitocôndrias/metabolismo , Óvulo/citologia , Radioisótopos de Fósforo , Ribossomos/metabolismo , TrítioAssuntos
Óvulo/metabolismo , Proteínas/metabolismo , Xenopus/embriologia , Animais , Soluções Tampão , Isótopos de Carbono , Meios de Cultura , Grânulos Citoplasmáticos , Feminino , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Microscopia Eletrônica , Óvulo/citologia , Pinocitose , Cloreto de Sódio/farmacologia , TemperaturaAssuntos
Óvulo/metabolismo , Proteínas/metabolismo , Animais , Anuros , Proteínas Sanguíneas/análise , Isótopos de Carbono , Gonadotropina Coriônica/farmacologia , Cromatografia , Meios de Cultura , Técnicas de Cultura , Epitélio/metabolismo , Estradiol/farmacologia , Feminino , Masculino , Métodos , Ovulação/efeitos dos fármacos , Fatores de Tempo , TrítioAssuntos
Anuros , Técnicas de Cultura , Óvulo/metabolismo , Proteínas/metabolismo , Animais , Autorradiografia , Membrana Celular , Gonadotropina Coriônica , Meios de Cultura , Feminino , TrítioRESUMO
Administration of estradiol 17beta to male Xenopus laevis induces the appearance in serum of large amounts of a serum lipophosphoprotein which is not readily removed from the circulation and which can be resolved from other serum components by chromatography on triethylaminoethyl-cellulose. The initial rate of production of serum lipophosphoprotein is independent of the amount of estrogen administered, but the maximum rate of production and the time taken to attain this rate are dose-dependent.