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1.
Microb Pathog ; 185: 106437, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37913825

RESUMO

BACKGROUND: Our previous proteomics data obtained from Candida albicans recovered after serial passage in a murine model of systemic infection revealed that Orf19.36.1 expression correlates with the virulence of the fungus. Therefore, the impact of ORF19.36.1 upon virulence was tested in this study. MATERIALS & METHODS: CRISPR-Cas9 technology was used to construct homozygous C. albicans orf19.36.1 null mutants and the phenotypes of these mutants examined in vitro (filamentation, invasion, adhesion, biofilm formation, hydrolase activities) and in vivo assays. RESULTS: The deletion of ORF19.36.1 did not significantly impact the phenotypes examined or the virulence of C. albicans in two infection models. CONCLUSION: These results suggest that, although Orf19.36.1 expression correlates with virulence, this protein is not essential for C. albicans pathobiology.


Assuntos
Candida albicans , Candidíase , Proteínas Fúngicas , Animais , Camundongos , Candidíase/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Virulência/genética
2.
Microb Pathog ; 164: 105413, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35066070

RESUMO

Candida albicans is one of the major pathogens found in superficial and invasive infections. This fungus expresses several virulence factors and fitness attributes that are essential to the pathogenesis. In our previous study using a murine model of serial systemic candidiasis, virulence of the recovered C. albicans was enhanced and several virulence factors were also modified after five successive passages through mice (P1-P5). In this study, we aimed to correlate the different fungal morphologies, as well as the filamentation, invasion, and stress resistance abilities, of the cells recovered after passing through this model of infection with our previous findings regarding virulence. We obtained two colony morphology types from the recovered cells, differing in their peripheral filamentation. The morphotype 1, which presented zero to five filaments in the colony edge, was higher in P2, while morphotype 2, which presented more than five filaments in the colony edge, was predominant from P3 to P5. In general, morphotype 1 showed similar levels regarding filamentation in serum, invasion of agar and cells, and resistance to osmotic, oxidative, and thermal stress in all passages analyzed. The morphotype 2, however, exhibited an enhancement in these abilities over the passages. We observed an accordance with the increased virulence over the passages obtained in our previous study and the increased adaptability profile of morphotype 2. Therefore, we suggest that the behavior observed previously in the pathogenesis and virulence could be attributed, at least in part, to the greater presence and ability of morphotype 2.


Assuntos
Candida albicans , Candidíase , Animais , Candidíase/microbiologia , Proteínas Fúngicas , Camundongos , Virulência , Fatores de Virulência
3.
Artigo em Inglês | MEDLINE | ID: mdl-30348661

RESUMO

Paracoccidioidomycosis (PCM), caused by Paracoccidioides, is a systemic mycosis with granulomatous character and a restricted therapeutic arsenal. The aim of this work was to search for new alternatives to treat largely neglected tropical mycosis, such as PCM. In this context, the enzymes of the shikimate pathway constitute excellent drug targets for conferring selective toxicity because this pathway is absent in humans but essential for the fungus. In this work, we have used a homology model of the chorismate synthase (EC 4.2.3.5) from Paracoccidioides brasiliensis (PbCS) and performed a combination of virtual screening and molecular dynamics testing to identify new potential inhibitors. The best hit, CP1, successfully adhered to pharmacological criteria (adsorption, distribution, metabolism, excretion, and toxicity) and was therefore used in in vitro experiments. Here we demonstrate that CP1 binds with a dissociation constant of 64 ± 1 µM to recombinant chorismate synthase from P. brasiliensis and inhibits enzymatic activity, with a 50% inhibitory concentration (IC50) of 47 ± 5 µM. As expected, CP1 showed no toxicity in three cell lines. On the other hand, CP1 reduced the fungal burden in lungs from treated mice, similar to itraconazole. In addition, histopathological analysis showed that animals treated with CP1 displayed less lung tissue infiltration, fewer yeast cells, and large areas with preserved architecture. Therefore, CP1 was able to control PCM in mice with a lower inflammatory response and is thus a promising candidate and lead structure for the development of drugs useful in PCM treatment.


Assuntos
Antifúngicos/farmacologia , Descoberta de Drogas/métodos , Paracoccidioides/efeitos dos fármacos , Paracoccidioidomicose/tratamento farmacológico , Fósforo-Oxigênio Liases/antagonistas & inibidores , Quinolinas/farmacologia , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Células HeLa , Células Endoteliais da Veia Umbilical Humana , Humanos , Itraconazol/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Simulação de Dinâmica Molecular , Paracoccidioides/classificação , Paracoccidioides/isolamento & purificação , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/microbiologia , Análise de Sequência de Proteína
4.
Bioorg Chem ; 84: 87-97, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30496872

RESUMO

Drug repositioning is the process of discovery, validation and marketing of previously approved drugs for new indications. Our aim was drug repositioning, using ligand-based and structure-based computational methods, of compounds that are similar to two hit compounds previously selected by our group that show promising antifungal activity. Through the ligand-based method, 100 compounds from each of three databases (MDDR, DrugBank and TargetMol) were selected by the Tanimoto coefficient, as similar to LMM5 or LMM11. These compounds were analyzed by the scaffold trees, and up to 10 compounds from each database were selected. The structure-based method (molecular docking) using thioredoxin reductase as the target drug was performed as a complementary approach, resulting in six compounds that were tested in an in vitro assay. All compounds, particularly raltegravir, showed antifungal activity against the genus Paracoccidioides. Raltegravir, an antiviral drug, showed promising antifungal activity against the experimental murine paracoccidioidomycosis, with significant reduction of the fungal burden and decreased alterations in the lung structure of mice treated with 1 mg/kg of raltegravir. In conclusion, the combination of two in silico methods for drug repositioning was able to select an antiviral drug with promising antifungal activity for treatment of paracoccidioidomycosis.


Assuntos
Antifúngicos/farmacologia , Antivirais/farmacologia , Infecções Fúngicas Invasivas/tratamento farmacológico , Paracoccidioidomicose/tratamento farmacológico , Animais , Antifúngicos/síntese química , Antifúngicos/química , Antivirais/síntese química , Antivirais/química , Candida/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Relação Dose-Resposta a Droga , Reposicionamento de Medicamentos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Estrutura Molecular , Paracoccidioides/efeitos dos fármacos , Relação Estrutura-Atividade
5.
Biotechnol Lett ; 41(12): 1391-1401, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31659577

RESUMO

OBJECTIVE: To select potential ligands of ALS3 for drug development with anti-adhesion and/or anti-biofilm activities. METHODOLOGY: ALS3 model was considered stable by DM. The main features of protein flexibility were represented by two conformers which were used in the virtual screening. Twenty-four small molecules were selected for in vitro assays. Five of them presented the best biological activity with ability to inhibit the adhesion and C. albicans biofilm formation on abiotic surface. RESULTS: To select potential ligands of ALS3 for drug development with anti-adhesion and/or anti-biofilm activities. CONCLUSION: In silico tools application was able to select promising compounds with anti-adhesion activity, opening a new perspective of medical device treatment.


Assuntos
Antifúngicos/isolamento & purificação , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Adesão Celular/efeitos dos fármacos , Descoberta de Drogas/métodos , Proteínas Fúngicas/antagonistas & inibidores , Simulação de Acoplamento Molecular/métodos , Antifúngicos/química , Biofilmes/efeitos dos fármacos , Proteínas Fúngicas/química , Ligação Proteica , Conformação Proteica
6.
Microb Pathog ; 113: 225-232, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29074432

RESUMO

BACKGROUND: Although the majority of Candida infections are thought to come from endogenous sources, the healthcare workers' (HCWs) hands are being increasingly reported as vehicles for the transmission of pathogens. The aim of the present study was to evaluate the susceptibility of yeast isolated from the HCWs' hands and ICU (Intensive Care Unit) surfaces to antifungal agents and to determine the virulence potential and the genetic similarity between the same. METHODS: The susceptibility of yeasts from the HCWs' hands (n = 57) and ICU surfaces (n = 98) to conventional antifungals (fluconazole, voriconazole, amphotericin B and micafungin) was evaluated using the broth microdilution assay accordance with CLSI M27-A3. Additionally, some virulence factors such as adhesion and biofilm capacity on abiotic surfaces and on endothelial cells were evaluated, as well as germ tube formation. The similarity among yeast isolates were evaluated by the RAPD technique using the P4, OPA18 and OPE18 primers. RESULTS: Five species of Candida were found on the HCWs' hands (C. albicans, C. parapsilosis (sensu stricto), C. glabrata, C. tropicalis and C. krusei) and two on ICU surfaces (C. albicans and C. parapsilosis (sensu stricto)). The isolates from hands had higher resistance rates, with C. glabrata having the highest indices (100% FLU; 100% MFG). The similarity of C. albicans from HCWs and ICU surfaces was ≥80% according to the three primers analyzed. Candida spp. from hands had a greater potential for adhesion and biofilm formation on abiotic surfaces (p < 0.05). C. albicans from ICU surfaces had the greatest potential of adhesion on endothelial cells after 2 and 24 h, and presented high filamentation in SEM images and formed more and larger germ tubes (p < 0.05). CONCLUSION: the present study showed the significant virulence potential of yeasts transmitted in the hospital environment for the first time. Additionally, healthy people working in the ICU can carry these yeasts, which are capable of surviving in hospital surfaces, on their hands, offering a risk to patients, especially those who are immunocompromised.


Assuntos
Candida/isolamento & purificação , Infecção Hospitalar/microbiologia , Infecção Hospitalar/transmissão , Mãos/microbiologia , Pessoal de Saúde , Fatores de Virulência/análise , Antifúngicos/farmacologia , Biofilmes/crescimento & desenvolvimento , Brasil/epidemiologia , Candida/classificação , Candida/efeitos dos fármacos , Candida/patogenicidade , Candidíase/transmissão , Farmacorresistência Fúngica , Células Endoteliais/microbiologia , Humanos , Unidades de Terapia Intensiva , Testes de Sensibilidade Microbiana , Técnica de Amplificação ao Acaso de DNA Polimórfico
7.
Appl Microbiol Biotechnol ; 100(9): 4015-25, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26695160

RESUMO

The thioredoxin system plays a critical role in maintaining the cytoplasm redox state, participating in functions that are important to the cellular viability of fungi. Although functional and structural information on targets in human pathogenic fungi has been scarcely described in the literature, such studies are essential for in silico drug design and biotechnological applications. Therefore, the aims of the present study were to produce recombinant proteins of the thioredoxin system from Candida albicans and evaluate their possible use as prophylactic or alternative therapies against the most important pathogenic fungus associated with nosocomial infections. We focused on biochemical and structural analyses of recombinant thioredoxin reductase from C. albicans with His-tag (CaTrxR-His) for further biotechnology applications. Heterologous CaTrxR-His was efficiently expressed in the soluble fraction of the Escherichia coli lysate. CaTrxR-His was obtained with a high level of purity and presented specific enzymatic activity. Conformational changes of the protein were observed at different pHs and temperatures, with higher thermal stability at pH 8.0. The CaTrxR-His vaccine was shown to effectively induce high levels of CaTrxR-specific immunoglobulin G antibodies in Balb/c mice and reduce the renal fungal burden of experimental disseminated candidiasis in mice. These data may greatly impact future development strategies for vaccine and drug designs against C. albicans infection.


Assuntos
Candida albicans/enzimologia , Tiorredoxina Dissulfeto Redutase/imunologia , Tiorredoxina Dissulfeto Redutase/metabolismo , Animais , Anticorpos Antifúngicos/sangue , Antígenos de Fungos/genética , Antígenos de Fungos/metabolismo , Candida albicans/genética , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Concentração de Íons de Hidrogênio , Imunoglobulina G/sangue , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Temperatura , Tiorredoxina Dissulfeto Redutase/genética
8.
Molecules ; 19(3): 2925-56, 2014 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-24609016

RESUMO

Nosocomial infections caused by fungi have increased greatly in recent years, mainly due to the rising number of immunocompromised patients. However, the available antifungal therapeutic arsenal is limited, and the development of new drugs has been slow. Therefore, the search for alternative drugs with low resistance rates and fewer side effects remains a major challenge. Plants produce a variety of medicinal components that can inhibit pathogen growth. Studies of plant species have been conducted to evaluate the characteristics of natural drug products, including their sustainability, affordability, and antimicrobial activity. A considerable number of studies of medicinal plants and alternative compounds, such as secondary metabolites, phenolic compounds, essential oils and extracts, have been performed. Thus, this review discusses the history of the antifungal arsenal, surveys natural products with potential antifungal activity, discusses strategies to develop derivatives of natural products, and presents perspectives on the development of novel antifungal drug candidates.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Pesquisa/tendências , Animais , Fungos/efeitos dos fármacos , História do Século XX , Humanos , Pesquisa/história
9.
Future Microbiol ; : 1-14, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39268668

RESUMO

Aim: To search for potential inhibitors to homoserine dehydrogenase (HSD) in Paracoccidioides brasiliensis the causative agent of paracoccidioidomycosis, an infection with a high mortality rate in Brazil.Materials & methods: The enzyme was modeled and used in the virtual screening of the compounds. The library was first screened by the Autodock, in which 66 molecules were better ranked than substrate, and then, also evaluated by the Molegro and Gold programs.Results: The HS23 and HS87 molecules were selected in common by the three programs, and ADME/Tox evaluation indicates they are not toxic. The molecular dynamics of PbHSD bonded to ligands showed stable complexes until 50 ns. To validate the results, compounds were purchased for assays of minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), synergic profile with Amphotericin B (AmB) and cytotoxicity. The two molecules presented MIC of 32 µg/ml and MFC of 64 µg/ml against the P. brasiliensis (strain Pb18). They also showed synergistic activity with AmB and a lack of toxicity against Hela and Vero cell lines.Conclusion: These results suggest that the HS23 and HS87 are promising candidates as PbHSD inhibitors and may be used as hits for the development of new drugs against paracoccidioidomycosis.


[Box: see text].

10.
J Biomol Struct Dyn ; 41(7): 2971-2980, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35196960

RESUMO

The development of new drugs against Mycobacterium tuberculosis is an essential strategy for fighting drug resistance. Although 3-dehydroquinate dehydratase (MtDHQ) is known to be a highly relevant target for M. tuberculosis, current research shows new putative inhibitors of MtDHQ selected by a large-scale ensemble-docking strategy combining ligand- and target-based chemoinformatic methods to deep learning. Initial chemical library was reduced from 216 million to approximately 460 thousand after pharmacophore, toxicity and molecular weight filters. Final library was subjected to an ensemble-docking protocol in GOLD which selected the top 300 molecules (GHITS). GHITS displayed different structures and characteristics when compared to known inhibitors (KINH). GHITS were further screened by post-docking analysis in AMMOS2 and deep learning virtual screening in DeepPurpose. DeepPurpose predicted that a number of GHITS had comparable or better affinity for the target than KINH. The best molecule was selected by consensus ranking using GOLD, AMMOS2 and DeepPurpose scores. Molecular dynamics revealed that the top hit displayed consistent and stable binding to MtDHQ, making strong interactions with active-site loop residues. Results forward new putative inhibitors of MtDHQ and reinforce the potential application of artificial intelligence methods for drug design. This work represents the first step in the validation of these molecules as inhibitors of MtDHQ.


Assuntos
Aprendizado Profundo , Mycobacterium tuberculosis , Ligantes , Inteligência Artificial
11.
Future Med Chem ; 15(24): 2239-2255, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38014535

RESUMO

Background: Paracoccidioidomycosis (PCM) is a systemic infection caused by Paracoccidioides spp. (Pb). PCM can be associated or clinically confused with tuberculosis (TB), another pulmonary infection, caused by Mycobacterium tuberculosis (Mtb). Futhermore, the long treatment time of TB and PCM and the cases of TB drug resistance impose difficulties for the cure of these diseases. Results: New 1,3,4-oxadiazoles containing the 4-methoxynaphthalene ring were synthesized and their antimicrobial activity was evaluated against Pb and Mtb. The derivative 6n (with 2-hydroxy-5-nitrophenyl subunit) is the most promising of the series. Conclusion: The 1,3,4-oxadiazole 6n can be used as a prototype drug candidate, with anti-Pb and anti-MTb activities, showing a broad-spectrum profile for the treatment of both pulmonary infections.


Assuntos
Anti-Infecciosos , Mycobacterium tuberculosis , Paracoccidioidomicose , Tuberculose , Humanos , Oxidiazóis/farmacologia , Chumbo/uso terapêutico , Tuberculose/tratamento farmacológico , Paracoccidioidomicose/tratamento farmacológico , Paracoccidioidomicose/microbiologia , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico
12.
Photodiagnosis Photodyn Ther ; 42: 103498, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36882144

RESUMO

BACKGROUND: Onychomycosis (OM) is a common nail plate disorder caused by dermatophyte molds, yeasts, and non-dermatophyte molds, which use keratin in the nail plate as an energy source. OM is characterized by dyschromia, increased nail thickness, subungual hyperkeratosis, and onychodystrophy, and is typically treated with conventional antifungals despite frequent reports of toxicity, fungal resistance, and OM recurrence. Photodynamic therapy (PDT) with hypericin (Hyp) as a photosensitizer (PS) stands out as a promising therapeutic modality. When excited by a specific wavelength of light and in the presence of oxygen, to lead to photochemical and photobiological reactions on the selected targets. METHODS: OM diagnosis was made in three suspected cases, and the causative agents were identified by classical and molecular methods, and confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). Susceptibility of planktonic cells of the clinical isolates to conventional antifungals and PDT-Hyp was evaluated, and photoacoustic spectroscopy (PAS) of Hyp permeation in nail fragments ex vivo was analyzed. Furthermore, the patients opted to undergo PDT-Hyp treatment and were subsequently followed up. The protocol was approved by the human ethics committee (CAAE, number 14107419.4.0000.0104). RESULTS: The etiological agents of OM in patients ID 01 and ID 02 belonged to the Fusarium solani species complex, being identified as Fusarium keratoplasticum (CMRP 5514) and Fusarium solani (CMRP 5515), respectively. For patient ID 03, the OM agent was identified as Trichophyton rubrum (CMRP 5516). PDT-Hyp demonstrated a fungicidal effect in vitro, with reductions of p3 log10 (p < 0.0051 and p < 0.0001), and the PAS analyses indicated that Hyp could completely permeate through both healthy and OM-affected nails. After four sessions of PDT-Hyp, mycological cure was observed in all three cases, and after seven months, clinical cure was confirmed. CONCLUSION: PDT-Hyp showed satisfactory results in terms of efficacy and safety, and thus can be considered a promising therapy for the clinical treatment of OM.


Assuntos
Doenças da Unha , Onicomicose , Fotoquimioterapia , Humanos , Onicomicose/tratamento farmacológico , Onicomicose/microbiologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Fármacos Fotossensibilizantes/uso terapêutico , Fotoquimioterapia/métodos , Doenças da Unha/tratamento farmacológico
13.
Mycopathologia ; 174(1): 1-10, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22249604

RESUMO

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease, endemic in Latin America, caused by the thermal dimorphic fungus Paracoccidioides brasiliensis. Although some fungal antigens have already been characterized and used for serological diagnosis, cross-reactions have been frequently observed. Thus, the examination of fungal forms in clinical specimens or isolation of P. brasiliensis by culture is still the most frequent method for the diagnosis of this mycosis. In this study, a random peptide phage display library was used to select mimotopes of P. brasiliensis, which were employed as antigens in an indirect enzyme-linked immunosorbent assay. The protective monoclonal antibody against experimental PCM (anti-gp75) was used as molecular target to screen a phage display library. That approach led to a synthetic peptide named P2, which was synthesized and tested against PCM patients' sera to check whether it was recognized. There was significant recognition of P2 by sera of untreated PCM patients when compared with normal human sera. Sera from treated PCM group, patients with other mycosis or co-infected with HIV had much lower recognition of P2 than untreated patient group. The test showed a sensitivity of 100 and 94.59% of specificity in relation to human sera control. These data indicate a potential use of P2 as diagnostic tool in PCM. Its application for serological diagnosis of PCM may contribute to the development and standardization of simpler, faster and highly reproducible immunodiagnostic tests at low cost.


Assuntos
Anticorpos Antifúngicos/sangue , Micologia/métodos , Paracoccidioidomicose/diagnóstico , Peptídeos , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Biblioteca de Peptídeos , Peptídeos/isolamento & purificação , Sensibilidade e Especificidade , Testes Sorológicos/métodos
14.
Pathogens ; 10(3)2021 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-33800117

RESUMO

Candida albicans is the most common species isolated from nosocomial bloodstream infections. Due to limited therapeutic arsenal and increase of drug resistance, there is an urgent need for new antifungals. Therefore, the antifungal activity against C. albicans and in vivo toxicity of a 1,3,4-oxadiazole compound (LMM6) was evaluated. This compound was selected by in silico approach based on chemical similarity. LMM6 was highly effective against several clinical C. albicans isolates, with minimum inhibitory concentration values ranging from 8 to 32 µg/mL. This compound also showed synergic effect with amphotericin B and caspofungin. In addition, quantitative assay showed that LMM6 exhibited a fungicidal profile and a promising anti-biofilm activity, pointing to its therapeutic potential. The evaluation of acute toxicity indicated that LMM6 is safe for preclinical trials. No mortality and no alterations in the investigated parameters were observed. In addition, no substantial alteration was found in Hippocratic screening, biochemical or hematological analyzes. LMM6 (5 mg/kg twice a day) was able to reduce both spleen and kidneys fungal burden and further, promoted the suppresses of inflammatory cytokines, resulting in infection control. These preclinical findings support future application of LMM6 as potential antifungal in the treatment of invasive candidiasis.

15.
Front Cell Infect Microbiol ; 11: 684525, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249777

RESUMO

Invasive aspergillosis is one of the major causes of morbidity and mortality among invasive fungal infections. The search for new antifungal drugs becomes imperative when existing drugs are not able to efficiently treat these infections. Ebselen, is an organoselenium compound, already successfully approved in clinical trials as a repositioned drug for the treatment of bipolar disorder and prevention of noise-induced hearing loss. In this study, we aimed to reposition ebselen for the treatment of invasive aspergillosis by showing ebselen effectiveness in a murine model. For this, BALB/c mice were immunosuppressed and infected systemically with Aspergillus fumigatus. Animals were divided and treated with ebselen, voriconazole, or drug-free control, for four days. The kidneys were used for CFU count and, histopathological and cytokine analysis. Ebselen was able to significantly reduce the fungal burden in the kidneys of infected mice with efficacy comparable with voriconazole treatment as both had reductions to the same extent. The absence of hyphae and intact kidney tissue structure observed in the histopathological sections analyzed from treated groups corroborate with the downregulation of IL-6 and TNF. In summary, this study brings for the first time in vivo evidence of ebselen efficacy against invasive aspergillosis. Despite these promising results, more animal studies are warranted to evaluate the potential role of ebselen as an alternative option for the management of invasive aspergillosis in humans.


Assuntos
Aspergilose , Infecções Fúngicas Invasivas , Animais , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Azóis , Modelos Animais de Doenças , Infecções Fúngicas Invasivas/tratamento farmacológico , Isoindóis , Camundongos , Camundongos Endogâmicos BALB C , Compostos Organosselênicos
16.
Biochem Biophys Rep ; 21: 100724, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32021910

RESUMO

An elevated prevalence of cryptococcal infection is a tendency in low-income countries and constitutes a global public health problem due to factors such as the limited efficacy of antifungal therapy and the AIDS/transplant immunocompromised patients. The fungus Cryptococcus neoformans, implicated in this burden, has had several genes validated as drug targets. Among them, the thioredoxin system is one of the major regulators of redox homeostasis and antioxidant defense acting on protein disulfide bonds. Thioredoxin 1 from C. neoformans (CnTrx1) was cloned and expressed in E. coli and the recombinant protein was purified and crystallized. Functional assay shows that CnTrx1 catalyzes the reduction of insulin disulfide bonds using dithiothreitol, while acting as a monomer in solution. The crystal structure of oxidized CnTrx1 at 1.80 Å resolution presents a dimer in the asymmetric unit with typical Trx-fold. Differences between the monomers in the asymmetric unit are found specially in the loop leading to the Cys-Gly-Pro-Cys active-site motif, being even larger when compared to those found between reduced and oxidized states of other thioredoxins. Although the thioredoxins have been isolated and characterized from many organisms, this new structural report provides important clues for understanding the binding and specificity of CnTrx1 to its targets.

17.
PLoS One ; 15(1): e0227876, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31935275

RESUMO

Candida krusei is one of the most common agents of invasive candidiasis and candidemia worldwide, leading to high morbidity and mortality rates. This species has become a problem due to its intrinsic resistance and reduced susceptibility to azoles and polyenes. Moreover, the number of antifungal drugs available for candidiasis treatment is limited, demonstrating the urgent need for the discovery of novel alternative therapies. In this work, the in vivo and in vitro activities of a new oxadiazole (LMM11) were evaluated against C. krusei. The minimum inhibitory concentration ranged from 32 to 64 µg/mL with a significant reduction in the colony forming unit (CFU) count (~3 log10). LMM11 showed fungicidal effect, similar to amphotericin, reducing the viable cell number (>99.9%) in the time-kill curve. Yeast cells presented morphological alterations and inactive metabolism when treated with LMM11. This compound was also effective in decreasing C. krusei replication inside and outside macrophages. A synergistic effect between fluconazole and LMM11 was observed. In vivo treatment with the new oxadiazole led to a significant reduction in CFU (0.85 log10). Furthermore, histopathological analysis of the treated group exhibited a reduction in the inflammatory area. Taken together, these results indicate that LMM11 is a promising candidate for the development of a new antifungal agent for the treatment of infections caused by resistant Candida species such as C. krusei.


Assuntos
Antifúngicos/química , Candida/efeitos dos fármacos , Candidíase/tratamento farmacológico , Oxidiazóis/química , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Candida/patogenicidade , Candidíase/microbiologia , Sobrevivência Celular/efeitos dos fármacos , Humanos , Macrófagos/efeitos dos fármacos , Oxidiazóis/farmacologia , Células-Tronco/efeitos dos fármacos
18.
PLoS One ; 15(12): e0243197, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33306677

RESUMO

Vulvovaginal candidiasis (VVC) is a common vaginitis that affects women, especially in childbearing age, caused by Candida albicans in almost 80% of cases. Considering the limited drug arsenal available and the increasing fungal resistance profile, the search for new therapeutic sources with low toxicity and easy administration should be supported. Propolis has been used as a traditional medicine for multiple diseases, considering its particular composition and pharmaceutical properties that permits its wide applicability; it has also emerged as a potential antifungal agent. Thus, this study performed an in vitro and in vivo investigation into the efficacy of a new mucoadhesive thermoresponsive platform for propolis delivery (MTS-PRPe) in a preclinical murine model of VVC treatment caused by C. albicans. The methodologies involved chemical analysis, an assessment of the rheological and mucoadhesive properties of propolis formulations, in vitro and in vivo antifungal evaluations, histological evaluations and electron microscopy of the vaginal mucosa. The results demonstrated the antifungal activity of propolis extract and MTS-PRP against the standard strain and a fluconazole-resistant clinical isolate of C. albicans, in both in vitro and in vivo assays. These results were similar and even better, depending on the propolis concentration, when compared to nystatin. Thus, the formulation containing propolis exhibited good performance against C. albicans in a vulvovaginal candidiasis experimental model, representing a promising opportunity for the treatment of this infection.


Assuntos
Apiterapia/métodos , Candidíase Vulvovaginal/terapia , Sistemas de Liberação de Medicamentos/métodos , Própole/uso terapêutico , Adesivos , Animais , Antifúngicos/uso terapêutico , Candida albicans/efeitos dos fármacos , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Própole/administração & dosagem , Reologia
19.
Pharmacol Ther ; 195: 21-38, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30347212

RESUMO

The need for better antifungal therapy is commonly accepted in view of the high mortality rates associated with systemic infections, the low number of available antifungal classes, their associated toxicity and the increasing number of infections caused by strains with natural or acquired resistance. The urgency to expand the range of therapeutic options for the treatment of fungal infections has led researchers in recent decades to seek alternative antifungal targets when compared to the conventional ones currently used. Although new potential targets are reported, translating the discoveries from bench to bedside is a long process and most of these drugs fail to reach the patients. In this review, we discuss the development of antifungal drugs focusing on the approach of drug repurposing and the search for novel drugs for classical targets, the most recently described gene targets for drug development, the possibilities of immunotherapy using antibodies, cytokines, therapeutic vaccines and antimicrobial peptides.


Assuntos
Antifúngicos/uso terapêutico , Micoses/terapia , Animais , Anticorpos Monoclonais/uso terapêutico , Produtos Biológicos/uso terapêutico , Desenvolvimento de Medicamentos , Humanos , Imunoterapia , Vacinas/uso terapêutico
20.
Artigo em Inglês | MEDLINE | ID: mdl-31293987

RESUMO

Candida albicans is the major pathogen isolated from nosocomial bloodstream infections, leading to higher mortality rates. Thus, due to its clinical relevance, studies aiming to understand host-pathogen interactions in C. albicans infection are necessary. Therefore, we performed proteomic analysis using a murine model of serial systemic infection by C. albicans to evaluate possible changes in the protein profile of the pathogen over time. Firstly, we observed a reduction in the median survival time of infected animals with increasing passage number, suggesting a higher pathogenicity acquired during repeated infections. By LC-MS/MS, it was possible to obtain protein profiles from the wild-type strain (WT) and compare them to proteins extracted from Candida cells recovered from infected tissues during passages one, three, and four (P1, P3, and P4). We obtained 56, 29, and 97 proteins in P1, P3, P4, respectively, all varying in abundance. Regarding biological processes, the majority of proteins were related to carbohydrate metabolism, stress responses and amino acid metabolism. The proteins were also categorized according to their potential role in virulence traits, such as biofilm production, yeast-to-hyphae transition, phenotypic switching, proteins related to stress responses, and uncharacterized proteins. Therefore, serial infection in combination with proteomic approach enabled us to deepen the existing knowledge about host-pathogen interactions.


Assuntos
Candida albicans/metabolismo , Candidíase/metabolismo , Proteínas Fúngicas/metabolismo , Interações Hospedeiro-Patógeno/fisiologia , Proteômica , Aminoácidos/metabolismo , Animais , Biofilmes , Candida albicans/patogenicidade , Candidíase/microbiologia , Metabolismo dos Carboidratos , Cromatografia Líquida , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Espectrometria de Massas em Tandem , Virulência , Fatores de Virulência/metabolismo
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