RESUMO
Our previous research suggests an important regulatory role of CK2-mediated phosphorylation of enzymes involved in the thymidylate biosynthesis cycle, i.e., thymidylate synthase (TS), dihydrofolate reductase (DHFR), and serine hydroxymethyltransferase (SHMT). The aim of this study was to show whether silencing of the CK2α gene affects TS and DHFR expression in A-549 cells. Additionally, we attempted to identify the endogenous kinases that phosphorylate TS and DHFR in CCRF-CEM and A-549 cells. We used immunodetection, immunofluorescence/confocal analyses, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), in-gel kinase assay, and mass spectrometry analysis. Our results demonstrate that silencing of the CK2α gene in lung adenocarcinoma cells significantly increases both TS and DHFR expression and affects their cellular distribution. Additionally, we show for the first time that both TS and DHFR are very likely phosphorylated by endogenous CK2 in two types of cancer cells, i.e., acute lymphoblastic leukaemia and lung adenocarcinoma. Moreover, our studies indicate that DHFR is phosphorylated intracellularly by CK2 to a greater extent in leukaemia cells than in lung adenocarcinoma cells. Interestingly, in-gel kinase assay results indicate that the CK2α' isoform was more active than the CK2α subunit. Our results confirm the previous studies concerning the physiological relevance of CK2-mediated phosphorylation of TS and DHFR.
Assuntos
Adenocarcinoma de Pulmão , Tetra-Hidrofolato Desidrogenase , Humanos , Fosforilação , Tetra-Hidrofolato Desidrogenase/química , Timidilato Sintase/metabolismoRESUMO
Mast cells (MCs) play important roles in normal immune responses and pathological states. The location of MCs on the boundaries between tissues and the external environment, including gut mucosal surfaces, lungs, skin, and around blood vessels, suggests a multitude of immunological functions. Thus, MCs are pivotal for host defense against different antigens, including allergens and microbial pathogens. MCs can produce and respond to physiological mediators and chemokines to modulate inflammation. As long-lived, tissue-resident cells, MCs indeed mediate acute inflammatory responses such as those evident in allergic reactions. Furthermore, MCs participate in innate and adaptive immune responses to bacteria, viruses, fungi, and parasites. The control of MC activation or stabilization is a powerful tool in regulating tissue homeostasis and pathogen clearance. Moreover, MCs contribute to maintaining the homeostatic equilibrium between host and resident microbiota, and they engage in crosstalk between the resident and recruited hematopoietic cells. In this review, we provide a comprehensive overview of the functions of MCs in health and disease. Further, we discuss how mouse models of MC deficiency have become useful tools for establishing MCs as a potential cellular target for treating inflammatory disorders.
Assuntos
Homeostase/imunologia , Infecções/imunologia , Mastócitos/imunologia , Neoplasias/imunologia , Animais , Humanos , Imunidade/imunologia , Inflamação/imunologiaRESUMO
Our study aimed to characterise the action mode of N-phenacyldibromobenzimidazoles against C. albicans and C. neoformans. Firstly, we selected the non-cytotoxic most active benzimidazoles based on the structure-activity relationships showing that the group of 5,6-dibromobenzimidazole derivatives are less active against C. albicans vs. 4,6-dibromobenzimidazole analogues (5e-f and 5h). The substitution of chlorine atoms to the benzene ring of the N-phenacyl substituent extended the anti-C. albicans action (5e with 2,4-Cl2 or 5f with 3,4-Cl2). The excellent results for N-phenacyldibromobenzimidazole 5h against the C. albicans reference and clinical isolate showed IC50 = 8 µg/mL and %I = 100 ± 3, respectively. Compound 5h was fungicidal against the C. neoformans isolate. Compound 5h at 160-4 µg/mL caused irreversible damage of the fungal cell membrane and accidental cell death (ACD). We reported on chitinolytic activity of 5h, in accordance with the patterns observed for the following substrates: 4-nitrophenyl-N-acetyl-ß-d-glucosaminide and 4-nitrophenyl-ß-d-N,N',Nâ³-triacetylchitothiose. Derivative 5h at 16 µg/mL: (1) it affected cell wall by inducing ß-d-glucanase, (2) it caused morphological distortions and (3) osmotic instability in the C. albicans biofilm-treated. Compound 5h exerted Candida-dependent inhibition of virulence factors.
Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Benzimidazóis/química , Animais , Antifúngicos/síntese química , Antifúngicos/toxicidade , Benzimidazóis/síntese química , Benzimidazóis/farmacologia , Benzimidazóis/toxicidade , Biofilmes/efeitos dos fármacos , Candida albicans/citologia , Candida albicans/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Quitina/metabolismo , Chlorocebus aethiops , Cryptococcus neoformans/citologia , Cryptococcus neoformans/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Testes de Sensibilidade Microbiana , Microscopia Confocal , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade , Células VeroRESUMO
A newly synthetized series of N-phenacyl derivatives of 2-mercaptobenzoxazole, including analogues of 5-bromo- and 5,7-dibromobenzoxazole, were screened against Candida strains and the action mechanism was evaluated. 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(4-bromophenyl)ethanone (5d), 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(2,3,4-trichloro-phenyl)ethanone (5i), 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(2,4,6-trichlorophenyl)ethanone (5k) and 2-[(5-bromo-1,3-benzoxazol-2-yl)sulfanyl]-1-phenylethanone (6a) showed anti-C. albicans SC5314 activity, where 5d displayed MICT = 16 µg/mL (%R = 100) and a weak anti-proliferative activity against the clinical strains: C. albicans resistant to azoles (Itr and Flu) and C. glabrata. Derivatives 5k and 6a displayed MICP = 16 µg/mL and %R = 64.2 ± 10.6, %R = 88.0 ± 9.7, respectively, against the C. albicans isolate. Derivative 5i was the most active against C. glabrata (%R = 53.0 ± 3.5 at 16 µg/mL). Benzoxazoles displayed no MIC against C. glabrata. Benzoxazoles showed a pleiotropic action mode: (1) the total sterols content was perturbed; (2) 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(3,4-dichlorophenyl)ethanol and 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(2,3,4-trichlorophenyl)ethanol (8h-i) at the lowest fungistatic conc. inhibited the efflux of the Rho123 tracker during the membrane transport process; (3) mitochondrial respiration was affected/inhibited by the benzoxazoles: 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(4-chlorophenyl)ethanol and 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(4-bromophenyl)ethanol 8c-d and 8i. Benzoxazoles showed comparable activity to commercially available azoles due to (1) the interaction with exogenous ergosterol, (2) endogenous ergosterol synthesis blocking as well as (3) membrane permeabilizing properties typical of AmB. Benzoxazoles display a broad spectrum of anti-Candida activity and action mode towards the membrane without cross-resistance with AmB; furthermore, they are safe to mammals.
Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Benzoxazóis/química , Benzoxazóis/farmacologia , Candida/efeitos dos fármacos , Testes de Sensibilidade MicrobianaRESUMO
Candida albicans CNB1 plays a role in the response in vitro and in vivo to stress generated by PB-WUT-01, namely 1,3-dimethyl-7-(2-((1-(3-(perbromo-2H-benzo[d][1,2,3]triazol-2-yl)propyl)-1H-1,2,3-triazol-4-yl)methoxy)propyl)-1H-purine-2,6(3H,7H)-dione. The antifungal mechanism involved the calcineurin pathway-regulated genes SAP9-10. Galleria mellonella treated with PB-WUT-01 (at 0.64 µg/mg) showed limited candidiasis and remained within the highest survival rates. The molecular mode of action of PB-WUT-01 was rationalized by in silico docking studies toward both human and C. albicans calcineurin A (CNA) and calcineurin B (CNB) complexes, respectively. PB-WUT-01 acting as a calcineurin inhibitor in the C. albicans cells enhances the cells' susceptibility. Therefore it could be a suitable alternative treatment in patients with candidiasis.
Assuntos
Antifúngicos/farmacologia , Inibidores de Calcineurina/farmacologia , Calcineurina/metabolismo , Candida albicans/efeitos dos fármacos , Teofilina/análogos & derivados , Animais , Antifúngicos/síntese química , Antifúngicos/metabolismo , Apoptose/efeitos dos fármacos , Ácido Aspártico Endopeptidases/metabolismo , Biofilmes/efeitos dos fármacos , Inibidores de Calcineurina/síntese química , Inibidores de Calcineurina/metabolismo , Candida albicans/fisiologia , Chlorocebus aethiops , Proteínas Fúngicas/metabolismo , Larva/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Mariposas , Ligação Proteica , Teofilina/metabolismo , Teofilina/farmacologia , Células VeroRESUMO
BACKGROUND: The combination effect of 5-fluorouracil (5-FU) with either CX-4945 or a new inhibitor of protein kinase CK2, namely 14B (4,5,6,7-tetrabromo-1-(3-bromopropyl)-2-methyl-1H-benzimidazole), on the viability of MCF-7 and triple-negative MDA-MB-231 breast cancer cell lines was studied. METHODS: Combination index (CI) values were determined using an MTT-based assay and the Chou-Talalay model. The effect of the tested drug combinations on pro-apoptotic properties and cell cycle progression was examined using flow cytometry. The activation of FAK, p38 MAPK, and ERK1/2 kinases and the expression of selected pro-apoptotic markers in MDA-MB-231 cell line after the combined treatment were evaluated by the western blot method. Confocal microscopy was used to examine actin network in MDA-MB-231. RESULTS: Our results showed that a synergistic effect (CI < 1) occurred in MDA-MB-231 after treatment with both combinations of 5-FU with 14B or CX-4945, whereas the combination of 5-FU and 14B evoked an antagonistic effect in MCF-7. We conclude that the synergistic interactions (CI < 1) observed for both the combinations of 5-FU and 14B or CX-4945 in MDA-MB-231 correlated with an activation of p38 MAPK, inhibition of FAK, increased expression of apoptogenic markers, prolongation of S-phase of cell cycle, and destabilization of actin network. CONCLUSIONS: The obtained results support the recent observation that CK2 inhibitors can improve 5-FU-based anticancer therapy and FAK kinase can be an attractive molecular target in breast cancer therapy.
Assuntos
Neoplasias da Mama/metabolismo , Fluoruracila/farmacologia , Quinase 1 de Adesão Focal/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Neoplasias da Mama/tratamento farmacológico , Caseína Quinase II/antagonistas & inibidores , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo , Sinergismo Farmacológico , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Naftiridinas/farmacologia , Fenazinas/farmacologiaRESUMO
With the appearance of the antifungal resistance, novel antifungal agents need to be identified. In this context new 2,5-disubstituted tetrazole derivatives containing benzothiazole, benzoxazole or phenylsulfonyl moiety were synthesized by N-alkylation of aryltetrazole with 2-[(3-chloropropyl)sulfanyl]-1,3-benzothiazole or 2-[(3-chloropropyl)sulfanyl]-1,3-benzoxazole and Michael-type addition of aryltetrazole to phenyl vinyl sulfone. The chemical structures of the synthesized compounds were confirmed by means of 1H NMR, 13C NMR, IR and HRMS spectral data. The compounds were tested against the moulds: Fusarium sambucinum, Fusarium oxysporum, Colletotrichum coccodes, Aspergillus niger, and the yeast Candida albicans. The results showed that among the moulds only C. coccodes was significantly sensitive to all the structures examined. All the tetrazole derivatives acted at the same level against C. albicans and demonstrated a high cell growth inhibition (97-99%) at the concentrations ranging from 16 to 0.0313µg/mL. The mode of action of 2-({3-[5-(4-chlorophenyl)-2H-tetrazol-2-yl]propyl}sulfanyl)-1,3-benzoxazole (5c) and 2-({3-[5-(2-chlorophenyl)-2H-tetrazol-2-yl]propyl}sulfanyl)-1,3-benzoxazole (5d) was established by verifying fungal growth in the presence of osmotic protector-sorbitol. The effect of compound 5c or 5d combined with Fluconazole was determined using the checkerboard method. The calculated fractional inhibitory concentration index (FIC) indicated antagonism (FIC >1). Additionally, survival experiments with lepidopteran Galleria mellonella treated with compounds 5c and 5d were performed and demonstrated the lack of toxicity of these compounds.
Assuntos
Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Tetrazóis/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Relação Dose-Resposta a Droga , Fungos/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade , Tetrazóis/síntese química , Tetrazóis/químicaRESUMO
A series of new N-substituted benzimidazole derivatives was synthesized and their antifungal activity against Candida albicans was evaluated. The chemical step included synthesis of appropriate ketones containing benzimidazole ring, reduction of ketones to the racemic alcohols, and acetylation of alcohols to the esters. All benzimidazole derivatives were obtained with satisfactory yields and in relatively short times. All synthesized compounds exhibit significant antifungal activity against Candida albicans 900028 ATCC (% cell inhibition at 0.25 µg concentration > 98%). Additionally, racemic mixtures of alcohols were separated by lipase-catalyzed kinetic resolution. In the enzymatic step a transesterification reaction was applied and the influence of a lipase type and solvent on the enantioselectivity of the reaction was studied. The most selective enzymes were Novozyme SP 435 and lipase Amano AK from Pseudomonas fluorescens (E > 100).
Assuntos
Antifúngicos/química , Benzimidazóis/química , Benzimidazóis/farmacologia , Lipase/química , Antifúngicos/farmacologia , Catálise , Cinética , Lipase/metabolismo , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Series of 4-(5-aryl-2H-tetrazol-2-yl)butan-2-ol, 1-(5-aryl-2H-tetrazol-2-yl)propan-2-ol and their acetates have been screened against Candida albicans. Among the tested compounds, (±)-1-[5-(2-chlorophenyl)-2H-tetrazol-2-yl]propan-2-yl acetate (E5) proved to be the most effective inhibitor of fungal growth and was further evaluated against young (adhesion phase) and mature biofilm in vitro. The activity exhibited by the tested tetrazole derivatives against C. albicans associated with minor cytotoxicity towards Vero epithelial cells make us suggest that E5 could be a promising structure in the development of new antifungals. Serine protease Kex2 appeared essential for the resistance mechanism. Further investigations of in vivo activity, drug interactions, and E5 structure optimization are needed.
Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/genética , Pró-Proteína Convertases/genética , Proteínas de Saccharomyces cerevisiae/genética , Tetrazóis/química , Tetrazóis/farmacologia , Animais , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/fisiologia , Chlorocebus aethiops , Farmacorresistência Fúngica/genética , Genes Fúngicos , Mutação , Relação Estrutura-Atividade , Células VeroRESUMO
The successful preventing and effective treatment of invasive Candida albicans infections required research focused on synthesis of new classes of agents and antifungal activity studies. Bromodichloromethyl-4-chloro-3-nitrophenyl sulfone (named compound 6); dichloromethyl-4-chloro-3-nitrophenyl sulfone (named 7); and chlorodibromomethyl-4-hydrazino-3-nitrophenyl sulfone (named 11) on inhibition of planktonic cells' growth, leucine arylamidase APE2 gene expression, and adhesion to epithelial cells were investigated. In vitro anti-Candida activities were determined against wild-types, and the morphogenesis mutants: Δefg1 and Δcph1. MICs of compounds 6, 7 and 11 (concentrated at 0.25-16µg/ml) were determined using the Clinical and Laboratory Standards Institute Broth Microdilution Method (M27-A3 Document). APE2 expression was analyzed using RT-PCR; relative quantification was normalized against ACT1 in cells growth in YEPD and on Caco-2 cell line. Adherence assay of C. albicans to Caco-2 was performed in 24-well-plate. The structure activity relationship suggested that sulfone containing hydrazine function at C-1 (compound 11) showed higher antifungal activity (cell inhibition%=100 at 1-16µg/ml) than the remaining sulfones with chlorine at C-1. Δcph1/Δefg1 was highly sensitive to compound 11, while the sensitivity was reduced in Δcph1/Δefg1::EFG1 (%=100 at 16-fold higher concentration). Compound 11 significantly affected adherence to epithelium (P ⩽0.05) and hyphae formation. The APE2 up-regulation plays role in sulfones' resistance on MAP kinase pathway. Either CPH1 or EFG1 play a role in the resistance mechanism in sulfones. The strain-dependent phenomenon is a factor in the sulfone resistance mechanism. Sulfones' mode of action was attributed to reduced virulence arsenal in terms of adhesiveness and pathogenic potential related to the APE2 expression and morphogenesis.
Assuntos
Antifúngicos/síntese química , Candida albicans/efeitos dos fármacos , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Sulfonas/química , Antifúngicos/química , Antifúngicos/farmacologia , Células CACO-2 , Candida albicans/enzimologia , Candida albicans/genética , Adesão Celular/efeitos dos fármacos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Humanos , Hidrazinas/química , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Sulfonas/síntese química , Sulfonas/farmacologiaRESUMO
The influence of halogenated methyl sulfones, i.e. bromodichloromethyl-4-chloro-3-nitrophenyl sulfone (named halogenated methyl sulfone 1), dichloromethyl-4-chloro-3-nitrophenyl sulfone (halogenated methyl sulfone 2), and chlorodibromomethyl-4-hydrazino-3-nitrophenyl sulfone (halogenated methyl sulfone 3), on cell growth inhibition, aspartic protease gene (SAP4-6) expression, adhesion to epithelium, and filamentation was investigated. Antifungal susceptibility of the halogenated methyl sulfones was determined with the M27-A3 protocol in the range of 16-0.0313 µg/mL. Adherence to Caco-2 cells was performed in 24-well plates; relative quantification was normalized against ACT1 in cells after 18 h of growth in YEPD and on Caco-2 cells. SAP4-6 expression was analyzed using RT-PCR. Structure-activity relationship studies suggested that halogenated methyl sulfone 1 containing bromodichloromethyl or dichloromethyl function at C-4 (halogenated methyl sulfone 2) of the phenyl ring showed the best activity (100% cell inhibition at 0.5 µg/mL), while hydrazine at C-1 (halogenated methyl sulfone 3) reduced the sulfone potential (100% = 4 µg/mL). SAP4-6 were up- or down-regulated depending on the strains' genetic background and the substitutions on the phenyl ring. Halogenated methyl sulfone 2 repressed germination and affected adherence to epithelium (P ≤ 0.05). The tested halogenated methyl sulfones interfered with the adhesion of Candida albicans cells to the epithelial tissues, without affecting their viability after 90 min of incubation. The mode of action of the halogenated methyl sulfones was attributed to the reduced virulence of C. albicans. SAP5 and SAP6 contribute to halogenated methyl sulfones resistance. Thus, halogenated methyl sulfones can inhibit biofilm formation due to their interference with adherence and with the yeast-to-hyphae transition.
Assuntos
Antifúngicos/síntese química , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Desenho de Fármacos , Sulfonas/síntese química , Sulfonas/farmacologia , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Células CACO-2 , Candida albicans/genética , Candida albicans/crescimento & desenvolvimento , Candida albicans/metabolismo , Candida albicans/patogenicidade , Adesão Celular/efeitos dos fármacos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , RNA Fúngico/metabolismo , RNA Mensageiro/metabolismo , Relação Estrutura-Atividade , VirulênciaRESUMO
Secreted aspartic proteases (Saps) are considered as key virulence factors of Candida albicans. Hopefully our outlook will widen the knowledge of SAP7's role in C. albicans pathogenesis. The goal of our study was to investigate SAP7 expression during C. albicans adhesion to intestinal human cells. Another objective was to study the role of SAP8-10 and transcriptional regulators: EFG1 and CPH1, using the mutants: Δsap, Δefg1, Δcph1 during growth on Caco-2 monolayer. SAP7 expression was analyzed using real time RT-PCR; relative quantification was normalized against ACT1 in cells after growth on Caco-2. Adherence assay of C. albicans to Caco-2 was performed in a 24-well-plate. The results proved that SAP7 can play a role during the initial adaptation of C. albicans to intestinal tract and decreases over time. Up-regulation of SAP7 occured in the absence of SAP8 and SAP10 (genetic alternations dependence). SAP7 can be regulated by the morphogensis' regulators during C. albicans growth on epithelium. Adhesion of the mutants was indistinguishable from SC5314. The lack of neither SAP8-10 nor EFG1/CPH1 influences the adhesive behaviour of C. albicans. Deletion of SAP8-10 resulted in no filamentation defects. The results help better understand the role of SAP7 during adhesion and morphogenesis in C. albicans.
Assuntos
Ácido Aspártico Endopeptidases/metabolismo , Candida albicans/enzimologia , Candida albicans/fisiologia , Neoplasias Colorretais/microbiologia , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/metabolismo , Hifas/crescimento & desenvolvimento , Fatores de Transcrição/metabolismo , Ácido Aspártico Endopeptidases/genética , Células CACO-2 , Candida albicans/genética , Candida albicans/crescimento & desenvolvimento , Proteínas de Ligação a DNA/genética , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Humanos , Hifas/enzimologia , Hifas/genética , Hifas/metabolismo , Fatores de Transcrição/genéticaRESUMO
The different members of the secreted aspartyl proteinase (Sap) family of the human pathogenic yeast Candida albicans are proposed to play different roles during infection and are differentially expressed at various body sites. In recent reports, expression analysis has focused on the genes SAP1-6, while the expression pattern of SAP7-10 was less well studied. We analyzed the SAP7-SAP10 expression profile of C. albicans under human serum influence that may be elucidated in the course of blood infection in humans and how this in vitro expression profile is associated with hyphal formation. The phenotypes of strains were examined under scanning electron microscopy. Quantitative RT-PCR (2-(deltadeltaC)T) was used to monitor SAP expression of C. albicans wild type cells and mutants lacking SAP9 and/or SAP10. Of the four analyzed SAP genes, only SAP7 was detectably induced in the double mutant and in the wild type strains in the model that mimics bloodstream infections. On the other hand, in the wild types (isolate 83 and CAF2-1), SAP7 was expressed 0.8- or 0.4-fold less than SAP10, respectively. Our findings suggest that Sap7 may respond to the challenge of the human blood environment. Furthermore, the results support the notion that compensatory upregulation of SAP7 and SAP8 in the deltasap9/deltasap10 mutant occurs in these conditions. SAP7-10 expression was strain-specific. Our findings point to a link between morphogenesis and expression of SAP9 in serum, where these conditions induce both hyphae and SAP9, but temporal gene expression patterns might be controlled by other factors.
Assuntos
Ácido Aspártico Proteases/metabolismo , Candida albicans/metabolismo , Meios de Cultura/química , Regulação Enzimológica da Expressão Gênica/fisiologia , Regulação Fúngica da Expressão Gênica/fisiologia , Micologia/métodos , Ácido Aspártico Proteases/genética , Candida albicans/genética , HumanosRESUMO
The arrangement of organelles in the sub-apical productive non-growing vacuolated hyphal cells of the high- and the low-penicillin-pro- ducing strains Penicillium chrysogenum was compared using transmission electron microscopy. In the productive cells of the high-yielding strain the endoplasmic reticulum and the polyribosomes with associated peroxisomes are frequently arranged at the periphery of the cytoplasm and around the vacuoles. At the high activity of penicillin G biosynthesis the immuno-label of the cytosolic isopenicillin N synthase is concentrated at the polyribosomes arranged in the peripheral cytoplasm and along the tonoplast as well as around the peroxisomes. On the basis of the obtained results the compartmentalization of the pathway of penicillin G biosymthesis is discussed. The obtained results support the phenylacetic acid detoxification hypothesis of penicillin G biosynthesis.
Assuntos
Penicilina G/metabolismo , Penicillium chrysogenum/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Transporte Biológico , Vias Biossintéticas , Oxirredutases/genética , Oxirredutases/metabolismo , Penicillium chrysogenum/genética , Penicillium chrysogenum/ultraestrutura , Fenilacetatos/metabolismoRESUMO
Fungal virulence factors represent a strategy for the design of new compounds with effective activities against Candida spp. Dichloromethyl-4-chloro-3-nitrophenylsulfone (named Compound 1) and chlorodibromomethyl-4-hydrazino-3-nitrophenylsulfone (Compound 2) versus Candida albicans virulence factors (SAP2 expression and adhesion to Caco-2 cell line) were investigated. Candida albicans SC5314 and its mutants: Δsap9, Δsap10, Δsap9/10 were used. MICs of the Compounds (concentrated at 0.0313-16 µg/ml) were determined using M27-A3. Percentage of cell inhibition was assessed spectrophotometrically (OD405) after 48 h at 35 °C. The SAP2 expression was analyzed with the use of RT-PCR; relative quantification was normalized against ACT1 in cells grown in YEPD and on Caco-2. Adherence assay of C. albicans to Caco-2 was performed in a 24-well-plate. Compound 1 showed higher activity (% = 100 at 4 µg/ml) than Compound 2 (MIC90 = 16 µg/ml). Dichloromethyl at the para position of the phenyl ring exerted anti-Candidal potential. Under Compound 1, SAP2 was down-regulated in all the strains (P ≤ 0.05). Conversely, SAP2 was over-expressed in Δsap9-10 (untreated cells) compared with the wild-type. The Compounds significantly affected adherence to epithelium (P ≤ 0.05). The tested sulfones interfered with the adhesion of C. albicans cells to the epithelial tissues without affecting their viability after 90-min of incubation. The Compounds' mode of action was attributed to the reduced adhesiveness and the lower SAP2 expression. Saps9-10 play a role in C. albicans adhesion and they can be involved in the sulfone resistance mechanisms.
Assuntos
Antifúngicos/farmacologia , Ácido Aspártico Endopeptidases/biossíntese , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Adesão Celular/efeitos dos fármacos , Proteínas Fúngicas/biossíntese , Expressão Gênica/efeitos dos fármacos , Sulfonas/farmacologia , Antifúngicos/química , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Células CACO-2 , Candida albicans/crescimento & desenvolvimento , Células Epiteliais/microbiologia , Proteínas Fúngicas/antagonistas & inibidores , Perfilação da Expressão Gênica , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espectrofotometria , Relação Estrutura-Atividade , Sulfonas/química , Temperatura , Fatores de TempoRESUMO
Environmental concerns and climate protection are gaining increasing emphasis nowadays. A growing number of industries and scientific fields are involved in this trend. Sustainable electronics is an emerging research strand. Environmentally friendly and biodegradable or biobased raw materials can be used for the development of green flexible electronic devices, which may serve to reduce the pollution generated by plastics and electronics waste. In this work, we present cytocompatible, electrically conductive structures of nanocarbon water-soluble composites based on starch films. To accomplish this goal, potato starch-based films with glycerol as a plasticiser were developed along with a water-soluble vehicle for nanocarbon-based electroconductive pastes specifically dedicated to screen printing technology. Films were characterized by optical microscopy, scanning electron microscopy (SEM) mechanical properties and surface free energy.
RESUMO
The challenge of integrating hydroxyapatite nanoparticles (nHAp) with polymers is hindered by the conflict between the hydrophilic and hygroscopic properties of nHAp and the hydrophobic properties of polymers. This conflict particularly affects the materials when calcium phosphates, including nHAp, are used as a filler in composites in thermal processing applications such as 3D printing with fused filament fabrication (FFF). To overcome this, we propose a one-step surface modification of nHAp with calcium stearate monolayer. Moreover, to build the scaffold with suitable mechanical strength, we tested the addition of nHAp with diverse morphology-spherical, plate- and rod-like nanoparticles. Our analysis showed that the composite of polycaprolactone (PCL) reinforced with nHAp with rod and plate morphologies modified with calcium stearate monolayer exhibited a significant increase in compressive strength. However, composites with spherical nHAp added to PCL showed a significant reduction in compressive modulus and compressive strength, but both parameters were within the applicability range of hard tissue scaffolds. None of the tested composite scaffolds showed cytotoxicity in L929 murine fibroblasts or MG-63 human osteoblast-like cells, supporting the proliferation of the latter. Additionally, PCL/nHAp scaffolds reinforced with spherical nHAp caused osteoactivation of bone marrow human mesenchymal stem cells, as indicated by alkaline phosphatase activity and COL1, RUNX2, and BGLAP expression. These results suggest that the calcium stearate monolayer on the surface of the nHAp particles allows the production of polymer/nHAp composites suitable for hard tissue engineering and personalized implant production in 3D printing using the FFF technique.
Assuntos
Durapatita , Nanopartículas , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais , Alicerces Teciduais/química , Durapatita/química , Durapatita/farmacologia , Camundongos , Animais , Humanos , Nanopartículas/química , Linhagem Celular , Poliésteres/química , Osteoblastos/metabolismo , Osteoblastos/citologia , Osteogênese/efeitos dos fármacos , Teste de MateriaisRESUMO
This study was planned to evaluate structural damages in adsorbed vaccines affected by freezing using scanning electron microscopy and X-ray analysis of the elements. Randomly selected 42 vials of eight different types of WHO pre-qualified adsorbed freeze-sensitive vaccines from 10 manufacturers were included in the study. Vaccines were kept at 5 °C. Selected numbers of vials from each type were then exposed to -25 °C for 24 h periods. All samples were evaluated for their structure using scanning electron microscopy, X-ray analysis of the elements and precipitation time. Scanning electron microscopy of vaccines affected by freezing showed either smooth or rough surfaced conglomerates associated with phosphate content of the precipitate. These vaccines precipitated 2-15 times faster compared to non-frozen samples. Non-frozen samples showed uniform flocculent structure either dense or dispersed. X-ray analysis of precipitates in frozen samples confirmed that the precipitate is mainly aluminium clutters. Scanning electron microscopy confirmed that the lattice structure of bonds between adsorbent and the antigen is broken and aluminium forms conglomerates that grow in size and weight. The precipitation time of vaccines affected by freezing is 4.5 times faster on average compared to non-frozen samples. These facts form the basis of the "shake test".
Assuntos
Congelamento , Vacinas/química , Adsorção , Técnicas de Química Analítica/métodos , Floculação , Humanos , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Raios XRESUMO
INTRODUCTION: The study evaluated the cell wall carbohydrates fraction in blastoconidia grown in YEPD medium at 30 degrees C and in the conglomerate of true hyphae grown in human serum at 37 degrees C. MATERIAL AND METHODS: The clinical isolate obtained from a child with widespread C. albicans infection was used in the study. The cells were broken with glass beads, centrifuged to harvest the cell wall followed by subjection to TFA hydrolysis and in the result of that released monosaccharides were detected by HPAEC-PAD. Both, serum and temperature conditions (37 degrees C) affected germination process influencing the cell wall carbohydrates content when incubation in serum was prolonged from 1 to 18 h. RESULTS: The mannan content of blastoconidia was almost twofold higher compared to filamentous forms (149.25 +/- 299.24 vs 77.26 +/- 122.07). The glucan content was threefold lower in blastoconidia compared to hyphae (251.86 +/- 243.44 vs 755.81 +/- 1299.30). The chitin level was fourfold lower in blastoconidia compared to filaments (23.86 +/- 54.09 vs 106.29 +/- 170.12). The reason for the differences in the carbohydrates content may be related to type of morphology induced in different environmental conditions. Among tested carbohydrates, glucan appeared to be present in appreciably larger amounts in both tested morphological fractions. The ultrastructure of the blastoconidial cell wall revealed striking differences compared to the hyphae indicating the carbohydrates content alterations for wall assembly during hyphal growth at alkaline pH and temp. 37 degrees C. CONCLUSIONS: The study provided evidence for the relationship between morphogenesis, cell-cell adhesion induced by serum and changes in the level of carbohydrates content.
Assuntos
Candida albicans/química , Candida albicans/ultraestrutura , Candidíase/microbiologia , Carboidratos/análise , Parede Celular/química , Candida albicans/classificação , Candida albicans/patogenicidade , Pré-Escolar , Humanos , Especificidade da EspécieRESUMO
Recent progress in medical sciences and therapy resulted in an increased number of immunocompromised individuals. Candida albicans is the leading opportunistic fungal pathogen causing infections in humans, ranging from superficial mucosal lesions to disseminated or bloodstream candidiasis. Superficial candidiasis not always presents a risk to the life of the infected host, however it significantly lowers the quality of life. Superficial Candida infections are difficult to treat and their frequency of occurrence is currently rising. To implement successful treatment doctors should be up to date with better understanding of C. albicans resistance mechanisms. Despite high frequency of Candida infections there is a limited number of antimycotics available for therapy. This review focuses on current understanding of the mode of action and resistance mechanisms to conventional and emerging antifungal agents for treatment of superficial and mucosal candidiasis.