Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
PLoS Pathog ; 19(4): e1011338, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37075064

RESUMO

Fungal pathogens overcome antifungal drug therapy by classic resistance mechanisms, such as increased efflux or changes to the drug target. However, even when a fungal strain is susceptible, trailing or persistent microbial growth in the presence of an antifungal drug can contribute to therapeutic failure. This trailing growth is caused by adaptive physiological changes that enable the growth of a subpopulation of fungal cells in high drug concentrations, in what is described as drug tolerance. Mechanistically, antifungal drug tolerance is incompletely understood. Here we report that the transcriptional activator Rpn4 is important for drug tolerance in the human fungal pathogen Candida albicans. Deletion of RPN4 eliminates tolerance to the commonly used antifungal drug fluconazole. We defined the mechanism and show that Rpn4 controls fluconazole tolerance via two target pathways. First, Rpn4 activates proteasome gene expression, which enables sufficient proteasome capacity to overcome fluconazole-induced proteotoxicity and the accumulation of ubiquitinated proteins targeted for degradation. Consistently, inhibition of the proteasome with MG132 eliminates fluconazole tolerance and resistance, and phenocopies the rpn4Δ/Δ mutant for loss of tolerance. Second, Rpn4 is required for wild type expression of the genes required for the synthesis of the membrane lipid ergosterol. Our data indicates that this function of Rpn4 is required for mitigating the inhibition of ergosterol biosynthesis by fluconazole. Based on our findings, we propose that Rpn4 is a central hub for fluconazole tolerance in C. albicans by coupling the regulation of protein homeostasis (proteostasis) and lipid metabolism to overcome drug-induced proteotoxicity and membrane stress.


Assuntos
Antifúngicos , Complexo de Endopeptidases do Proteassoma , Humanos , Antifúngicos/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteostase , Fluconazol , Candida albicans/metabolismo , Tolerância a Medicamentos , Ergosterol , Farmacorresistência Fúngica , Testes de Sensibilidade Microbiana
2.
Biomarkers ; 28(1): 97-110, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36377411

RESUMO

INTRODUCTION: Patients with cardiovascular disease (CVD) and acute SARS-CoV-2 infection might show an altered immune response during COVID-19. MATERIAL AND METHODS: Twenty-three patients with CVD and SARS-CoV-2 infection were prospectively enrolled and received a cardiological assessment at study entry and during follow-up visit. Inclusion criteria of our study were age older than 18 years, presence of CVD, and acute SARS-CoV-2 infection. The median age of the patient cohort was 69 (IQR 55-79) years. 12 (52.2%) patients were men. Peripheral monocytes and chemokine/cytokine profiles were analysed. RESULTS: Numbers of classical and non-classical monocytes were significantly decreased during acute SARS-CoV-2 infection compared to 3-month recovery. While classical monocytes reached the expected level in peripheral blood after 3 months, the number of non-classical monocytes remained significantly reduced. DISCUSSION: All three monocyte subsets exhibited changes of established adhesion and activation markers. Interestingly, they also expressed higher levels of pro-inflammatory cytokines like macrophage migration inhibitory factor (MIF) at the time of recovery, although MIF was only slightly increased during the acute phase. CONCLUSION: Changes of monocyte phenotypes and increased MIF expression after 3-month recovery from acute SARS-CoV-2 infection may indicate persistent, possibly long-lasting, pro-inflammatory monocyte function in CVD patients.


Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Monócitos , Citocinas , Quimiocinas
3.
Appl Microbiol Biotechnol ; 107(13): 4337-4353, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37204448

RESUMO

Brevibacillus laterosporus (Bl) is a Gram-positive and spore-forming bacterium. Insect pathogenic strains have been characterised in New Zealand, and two isolates, Bl 1821L and Bl 1951, are under development for use in biopesticides. However, growth in culture is sometimes disrupted, affecting mass production. Based on previous work, it was hypothesised that Tectiviridae phages might be implicated. While investigating the cause of the disrupted growth, electron micrographs of crude lysates showed structural components of putative phages including capsid and tail-like structures. Sucrose density gradient purification yielded a putative self-killing protein of ~30 kDa. N-terminal sequencing of the ~30 kDa protein identified matches to a predicted 25 kDa hypothetical and a 31.4 kDa putative encapsulating protein homologs, with the genes encoding each protein adjacent in the genomes. BLASTp analysis of the homologs of 31.4 kDa amino acid sequences shared 98.6% amino acid identity to the Linocin M18 bacteriocin family protein of Brevibacterium sp. JNUCC-42. Bioinformatic tools including AMPA and CellPPD defined that the bactericidal potential originated from a putative encapsulating protein. Antagonistic activity of the ~30 kDa encapsulating protein of Bl 1821L and Bl 1951during growth in broth exhibited bacterial autolytic activity. LIVE/DEAD staining of Bl 1821L cells after treatment with the ~30 kDa encapsulating protein of Bl 1821L substantiated the findings by showing 58.8% cells with the compromised cell membranes as compared to 37.5% cells in the control. Furthermore, antibacterial activity of the identified proteins of Bl 1821L was validated through gene expression in a Gram-positive bacterium Bacillus subtilis WB800N. KEY POINTS: • Gene encoding the 31.4 kDa antibacterial Linocin M18 protein was identified • It defined the autocidal activity of Linocin M18 (encapsulating) protein • Identified the possible killing mechanism of the encapsulins.


Assuntos
Bacillus , Bacteriocinas , Brevibacillus , Animais , Brevibacillus/genética , Brevibacillus/metabolismo , Antibacterianos/metabolismo , Insetos
4.
Curr Top Microbiol Immunol ; 425: 277-296, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31807895

RESUMO

Proper structure and function of the fungal cell wall are controlled by metabolic processes, as well as an interplay between a range of cellular organelles. Somewhat surprisingly, mitochondrial function has been shown to be important for proper cell wall biogenesis and integrity. Mitochondria also play a role in the susceptibility of fungi to cell wall-targeting drugs. This is true in a range of fungal species, including important human fungal pathogens. The biochemical mechanisms that explain the roles of mitochondria in cell wall biology have remained elusive, but studies to date strongly support the idea that mitochondrial control over cellular lipid homeostasis is at the core of these processes. Excitingly, recent evidence suggests that the mitochondria-lipid linkages drive resistance to the echinocandin drug caspofungin, a clinically important therapeutic that targets cell wall biosynthesis. Here, we review the state of affairs in mitochondria-fungal cell wall research and propose models that could be tested in future studies. Elucidating the mechanisms that drive fungal cell wall integrity through mitochondrial functions holds promise for developing new strategies to combat fungal infections, including the possibility to potentiate the effects of antifungal drugs and curb drug resistance.


Assuntos
Parede Celular , Fungos/citologia , Fungos/patogenicidade , Mitocôndrias/metabolismo , Micoses/microbiologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Parede Celular/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Equinocandinas/farmacologia , Equinocandinas/uso terapêutico , Fungos/efeitos dos fármacos , Humanos , Micoses/tratamento farmacológico
5.
Clin Rehabil ; 35(8): 1164-1174, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33685232

RESUMO

OBJECTIVE: To explore whether a structured counselling-based intervention increases vigorous physical activity behaviour of adolescent and young adult cancer survivors. DESIGN: Randomized controlled phase II trial. SETTING: University Cancer Center Hamburg, Germany. SUBJECTS: Eighty-nine participants (mean age 24.1 ± 6.3) were randomized to control (n = 44) or intervention group (n = 45). INTERVENTIONS: The intervention group was consulted about physical activity behaviour via interview (week 0), and telephone counselling (weeks 1, 3 and 12). The control group only received general physical activity guidelines for cancer survivors (week 0). MAIN MEASURES: The primary outcome was the rate of participants with ⩾9 metabolic equivalent (MET)-hours per week of vigorous activity post-intervention, measured with the International Physical Activity Questionnaire. Secondary outcomes included assessing physical activity behaviour (e.g. amount and type of physical activity) and quality of life. Assessments were completed in weeks 0 (baseline), 12 (post-intervention) and 52 (follow-up). RESULTS: Sixty-nine participants completed the post-intervention- and 47 the follow-up-assessment. The rate of participants performing vigorous physical activity increased from baseline to post-intervention for both without differing significantly (P = 0.541). Both increased their total metabolic equivalent from baseline to post-intervention (intervention group from 55.2 ± 43.7 to 61.7 ± 29.4, control group from 75.3 ± 81.4 to 88.3 ± 80.2). At follow-up the intervention group (73.7 ± 80.2) was more active than baseline when compared to the control group (78.5 ± 50.0). CONCLUSIONS: A structured counselling-based physical activity intervention did not significantly impact the level of vigorous physical activity behaviour in adolescent and young adult cancer survivors.


Assuntos
Sobreviventes de Câncer/psicologia , Aconselhamento/métodos , Exercício Físico/psicologia , Adolescente , Adulto , Metabolismo Energético/fisiologia , Feminino , Alemanha , Humanos , Masculino , Motivação , Neoplasias/terapia , Qualidade de Vida , Telefone , Adulto Jovem
6.
Curr Genet ; 65(4): 837-845, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30783741

RESUMO

Mitochondrial fission shows potential as a therapeutic target in non-infectious human diseases. The compound mdivi-1 was identified as a mitochondrial fission inhibitor that acts against the evolutionarily conserved mitochondrial fission GTPase Dnm1/Drp1, and shows promising data in pre-clinical models of human pathologies. Two recent studies, however, found no evidence that mdivi-1 acts as a mitochondrial fission inhibitor and proposed other mechanisms. In mammalian cells, Bordt et al. showed that mdivi-1 inhibits complex I in mitochondria (Dev Cell 40:583, 2017). In a second study, we have recently demonstrated that mdivi-1 does not trigger a mitochondrial morphology change in the human yeast pathogen Candida albicans, but impacts on endogenous nitric oxide (NO) levels and inhibits the key virulence property of hyphal formation (Koch et al., Cell Rep 25:2244, 2018). Here we discuss recent insights into mdivi-1's action in pathogenic fungi and the potential and challenges for repurposing it as an anti-infective. We also outline recent findings on the roles of mitochondrial fission in human and plant fungal pathogens, with the goal of starting the conversation on whether the research field of fungal pathogenesis can benefit from efforts in other disease areas aimed at developing therapeutic inhibitors of mitochondrial division.


Assuntos
Fungos/efeitos dos fármacos , Mitocôndrias/genética , Dinâmica Mitocondrial/genética , Quinazolinonas/farmacologia , Apoptose/genética , Complexo I de Transporte de Elétrons/genética , Fungos/patogenicidade , GTP Fosfo-Hidrolases/genética , Humanos , Hifas/efeitos dos fármacos , Hifas/crescimento & desenvolvimento , Hifas/patogenicidade , Mitocôndrias/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Óxido Nítrico/genética , Óxido Nítrico/metabolismo
7.
Psychooncology ; 26(12): 2127-2134, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28370730

RESUMO

OBJECTIVE: We developed an integrative day care clinic program for cancer patients focusing on mind-body techniques and health-promoting lifestyle modification (7-hour once-per-week group sessions over 12 weeks). METHODS: A cohort study design with a waiting group was implemented. Outcome parameters were assessed at the beginning, at the end of the active program, and at a 6-month follow-up. Patients waiting >4 and <12 weeks before treatment start were allocated to the waiting group and additionally assessed at the start of their day care program. Outcome measures included quality of life (FACT-G, FACT-B/C, WHO-5), fatigue (FACIT-F), depression/anxiety (HADS), and mood states (ASTS). A per protocol analysis using mixed linear models was performed. RESULTS: One hundred patients were screened on-site for eligibility. Eighty-six cancer survivors (83% female; mean age 53.7 ± 9.7 years; 49% breast cancer) were included into the study. Sixty-two patients were allocated to the intervention group and 24 patients, to the waiting group (mean waiting time 5 ± 1 weeks). Sixty-six data sets were included in the final analysis. Significant improvements were observed in favor of the intervention group after 12 weeks compared with the waiting group at the end of the waiting period for quality of life, anxiety/depression, and fatigue. Results from the 6-month follow-up for the whole study population showed lasting improvement of quality of life. CONCLUSIONS: The program can be considered as an effective means to improve quality of life, fatigue, and mental health of cancer patients. Moreover, it appears to have a sustainable effect, which has to be proved in randomized trials.


Assuntos
Terapia Comportamental/métodos , Neoplasias da Mama/terapia , Estilo de Vida , Terapias Mente-Corpo/métodos , Atenção Plena/métodos , Qualidade de Vida/psicologia , Adulto , Afeto , Idoso , Instituições de Assistência Ambulatorial , Neoplasias da Mama/psicologia , Estudos de Coortes , Hospital Dia , Depressão/terapia , Fadiga , Feminino , Humanos , Saúde Mental , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento
8.
Arch Toxicol ; 91(12): 3823-3833, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28612261

RESUMO

Antimony is utilized in a large variety of industrial applications, leading to significant environmental and occupational exposure. Mainly based on animal experiments, the IARC and MAK Commission have classified antimony and its inorganic compounds as Group 2B or 2 carcinogens, respectively. However, the underlying mode(s) of action are still largely unknown. In the present study, we investigated the impact of non-cytotoxic up to cytotoxic concentrations of SbCl3 on DNA DSB repair and cell cycle control in HeLa S3 cells. We induced DSB by γ-irradiation and analyzed inhibitory actions of antimony on potential molecular targets of the DSB repair machinery. Antimony disturbed cell cycle control, affecting phosphorylation of Chk1. Furthermore, the repair of DSB was impaired in the presence of antimony, as monitored by pulsed-field gel electrophoresis and γH2AX foci formation of cells in G1 and G2 phase. Specifically, BRCA1 and RAD51 were identified as molecular targets. Our results point towards an interference with both non-homologous end-joining (NHEJ) and homologous recombination (HR), and inhibitory effects may be explained by interactions with critical cysteine groups; this needs to be further investigated. Altogether, the results provide further evidence for the impairment of DNA repair processes as one underlying mechanism in antimony-induced carcinogenicity.


Assuntos
Antimônio/toxicidade , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Antimônio/administração & dosagem , Proteína BRCA1/genética , Ciclo Celular/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Dano ao DNA/efeitos da radiação , Reparo do DNA por Junção de Extremidades/efeitos dos fármacos , Reparo do DNA/efeitos da radiação , Células HeLa , Recombinação Homóloga/efeitos dos fármacos , Humanos , Rad51 Recombinase/genética , Radiação Ionizante
9.
Biochim Biophys Acta ; 1851(7): 977-86, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25720564

RESUMO

Steryl esters and triacylglycerols are the major storage lipids of the yeast Saccharomyces cerevisiae. Steryl esters are formed in the endoplasmic reticulum by the two acyl-CoA:sterol acyltransferases Are1p and Are2p, whereas steryl ester hydrolysis is catalyzed by the three steryl ester hydrolases Yeh1p, Yeh2p and Tgl1p. To shed light on the regulatory link between steryl ester formation and hydrolysis in the maintenance of cellular sterol and free fatty acid levels we employed yeast mutants which lacked the enzymes catalyzing the degradation of steryl esters. These studies revealed feedback regulation of steryl ester formation by steryl ester hydrolysis although in a Δtgl1Δyeh1Δyeh2 triple mutant the gene expression levels of ARE1 and ARE2 as well as protein levels and stability of Are1p and Are2p were not altered. Nevertheless, the capacity of the triple mutant to synthesize steryl esters was significantly reduced as shown by in vitro and in vivo labeling of lipids with [(14)C]oleic acid and [(14)C]acetate. Enzymatic analysis revealed that inhibition of steryl ester formation occurred at the enzyme level. As the amounts and the formation of sterols and fatty acids were also decreased in the triple mutant we concluded that defects in steryl ester hydrolysis also caused feedback inhibition on the formation of sterols and fatty acids which serve as precursors for steryl ester formation. In summary, this study demonstrates a regulatory link within the steryl ester metabolic network which contributes to non-polar lipid homeostasis in yeast cells.


Assuntos
Ésteres/metabolismo , Saccharomyces cerevisiae/metabolismo , Esterol Esterase/metabolismo , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Estabilidade Enzimática , Ácidos Graxos/metabolismo , Regulação Enzimológica da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Hidrólise , Metabolismo dos Lipídeos/genética , Organismos Geneticamente Modificados , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Esterol Esterase/genética , Esterol O-Aciltransferase/genética , Esterol O-Aciltransferase/metabolismo
10.
Arch Toxicol ; 90(10): 2369-88, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27334373

RESUMO

Single nucleotide polymorphisms (SNPs) are the most frequent type of genetic alterations between individuals. An SNP located within the coding sequence of a gene may lead to an amino acid substitution and in turn might alter protein function. Such a change in protein sequence could be functionally relevant and therefore might be associated with susceptibility to human diseases, such as cancer. DNA repair mechanisms are known to play an important role in cancer development, as shown in various human cancer syndromes, which arise due to mutations in DNA repair genes. This leads to the question whether subtle genetic changes such as SNPs in DNA repair genes may contribute to cancer susceptibility. In numerous epidemiological studies, efforts have been made to associate specific SNPs in DNA repair genes with altered DNA repair and cancer. The present review describes some of the common and most extensively studied SNPs in DNA repair genes and discusses whether they are functionally relevant and subsequently increase the likelihood that cancer will develop.


Assuntos
Reparo do DNA/genética , Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Animais , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/genética , Predisposição Genética para Doença , Humanos
11.
Environ Monit Assess ; 188(10): 564, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27629554

RESUMO

Monitoring the impacts of land-use practices is of particular importance with regard to biodiversity hotspots in developing countries. Here, conserving the high level of unique biodiversity is challenged by limited possibilities for data collection on site. Especially for such scenarios, assisting biodiversity assessments by remote sensing has proven useful. Remote sensing techniques can be applied to interpolate between biodiversity assessments taken in situ. Through this approach, estimates of biodiversity for entire landscapes can be produced, relating land-use intensity to biodiversity conditions. Such maps are a valuable basis for developing biodiversity conservation plans. Several approaches have been published so far to interpolate local biodiversity assessments in remote sensing data. In the following, a new approach is proposed. Instead of inferring biodiversity using environmental variables or the variability of spectral values, a hypothesis-based approach is applied. Empirical knowledge about biodiversity in relation to land-use is formalized and applied as ascription rules for image data. The method is exemplified for a large study site (over 67,000 km(2)) in central Chile, where forest industry heavily impacts plant diversity. The proposed approach yields a coefficient of correlation of 0.73 and produces a convincing estimate of regional biodiversity. The framework is broad enough to be applied to other study sites.


Assuntos
Biodiversidade , Monitoramento Ambiental/métodos , Agricultura Florestal/métodos , Florestas , Tecnologia de Sensoriamento Remoto/métodos , Árvores/classificação , Chile
12.
J Biol Chem ; 289(28): 19306-16, 2014 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-24847060

RESUMO

Lipid droplets are specific organelles for the storage of triacylglycerols and steryl esters. They are surrounded by a phospholipid monolayer with a small but specific set of proteins embedded. Assembly and insertion of proteins into this surface membrane is an intriguing question of lipid droplet biology. To address this question we studied the topology of Tgl3p, the major triacylglycerol lipase of the yeast Saccharomyces cerevisiae, on lipid droplets. Employing the method of limited proteolysis of lipid droplet surface proteins, we found that the C terminus of Tgl3p faces the inside of the organelle, whereas the N terminus is exposed at the cytosolic side of lipid droplets. Detailed analysis of the C terminus revealed a stretch of seven amino acids that are critical for protein stability and functionality. The negative charge of two aspartate residues within this stretch is crucial for lipase activity of Tgl3p. A portion of Tgl3p, which is located to the endoplasmic reticulum, exhibits a different topology. In the phospholipid bilayer of the endoplasmic reticulum the C terminus faces the cytosol, which results in instability of the protein. Thus, the topology of Tgl3p is important for its function and strongly dependent on the membrane environment.


Assuntos
Citosol/enzimologia , Retículo Endoplasmático/enzimologia , Membranas Intracelulares/enzimologia , Lipase/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Retículo Endoplasmático/genética , Estabilidade Enzimática , Lipase/genética , Estrutura Terciária de Proteína , Proteólise , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
13.
Biochim Biophys Acta ; 1842(10): 1393-402, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25016085

RESUMO

Tgl3p, Tgl4p and Tgl5p are the major triacylglycerol lipases of the yeast Saccharomyces cerevisiae catalyzing degradation of triacylglycerols stored in lipid droplets. Previous results from our laboratory (Athenstaedt and Daum, 2005, J. Biol. Chem. 280, 37301-37309) demonstrated that a yeast strain lacking all three triacylglycerol lipases accumulates not only triacylglycerols at high amount, but also steryl esters. Here we show a metabolic link between synthesis and mobilization of non-polar lipids. In particular, we demonstrate that a block in tri-acylglycerol degradation in a tgl3∆tgl4∆tgl5∆ triple mutant lacking all major triacylglycerol lipases causes marked changes in non-polar lipid synthesis. Under these conditions formation of triacylglycerols is reduced, whereas steryl ester synthesis is enhanced as shown by quantification of non-polar lipids, in vivo labeling of lipids using [(14)C]oleic acid and [(14)C]acetic acid as precursors, and enzyme analyses in vitro. In summary, this study demonstrates that triacylglycerol metabolism and steryl ester metabolism are linked processes. The importance of balanced storage and degradation of these components for lipid homeostasis in the yeast is highlighted.

14.
J Biol Chem ; 288(27): 19939-48, 2013 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-23673660

RESUMO

Tgl3p, the major triacylglycerol lipase of the yeast Saccharomyces cerevisiae, is a component of lipid droplets but is also present in the endoplasmic reticulum in a minor amount. Recently, it was shown that this enzyme can also serve as a lysophospholipid acyltransferase (Rajakumari, S., and Daum, G. (2010) Mol. Biol. Cell 21, 501-510). Here, we describe the effects of the presence/absence of triacylglycerols and lipid droplets on the functionality of Tgl3p. In a dga1Δlro1Δare1Δare2Δ quadruple mutant lacking all four triacylglycerol- and steryl ester-synthesizing acyltransferases and consequently the lipid droplets, the gene expression of TGL3 was only slightly altered. In contrast, protein level and stability of Tgl3p were markedly reduced in the absence of lipid droplets. Under these conditions, the enzyme was localized to the endoplasmic reticulum. Even the lack of the substrate, triacylglycerol, affected stability and localization of Tgl3p to some extent. Interestingly, Tgl3p present in the endoplasmic reticulum seems to lack lipolytic as well as acyltransferase activity as shown by enzymatic analysis and lipid profiling. Thus, we propose that the activity of Tgl3p is restricted to lipid droplets, whereas the endoplasmic reticulum may serve as a parking lot for this enzyme.


Assuntos
Retículo Endoplasmático/enzimologia , Lipase/metabolismo , Metabolismo dos Lipídeos/fisiologia , Lipídeos , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Retículo Endoplasmático/genética , Estabilidade Enzimática/fisiologia , Deleção de Genes , Genes Fúngicos , Lipase/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
15.
J Biol Chem ; 288(50): 36061-72, 2013 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-24187129

RESUMO

Saccharomyces cerevisiae, as well as other eukaryotes, preserves fatty acids and sterols in a biologically inert form, as triacylglycerols and steryl esters. The major triacylglycerol lipases of the yeast S. cerevisiae identified so far are Tgl3p, Tgl4p, and Tgl5p (Athenstaedt, K., and Daum, G. (2003) YMR313c/TGL3 encodes a novel triacylglycerol lipase located in lipid particles of Saccharomyces cerevisiae. J. Biol. Chem. 278, 23317-23323; Athenstaedt, K., and Daum, G. (2005) Tgl4p and Tgl5p, two triacylglycerol lipases of the yeast Saccharomyces cerevisiae, are localized to lipid particles. J. Biol. Chem. 280, 37301-37309). We observed that upon cultivation on oleic acid, triacylglycerol mobilization did not come to a halt in a yeast strain deficient in all currently known triacylglycerol lipases, indicating the presence of additional not yet characterized lipases/esterases. Functional proteome analysis using lipase and esterase inhibitors revealed a subset of candidate genes for yet unknown hydrolytic enzymes on peroxisomes and lipid droplets. Based on the conserved GXSXG lipase motif, putative functions, and subcellular localizations, a selected number of candidates were characterized by enzyme assays in vitro, gene expression analysis, non-polar lipid analysis, and in vivo triacylglycerol mobilization assays. These investigations led to the identification of Ayr1p as a novel triacylglycerol lipase of yeast lipid droplets and confirmed the hydrolytic potential of the peroxisomal Lpx1p in vivo. Based on these results, we discuss a possible link between lipid storage, lipid mobilization, and peroxisomal utilization of fatty acids as a carbon source.


Assuntos
Hidrolases de Éster Carboxílico/metabolismo , Lipase/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Desidrogenase do Álcool de Açúcar/metabolismo , Transporte Biológico , Hidrolases de Éster Carboxílico/genética , Meios de Cultura/química , Regulação Fúngica da Expressão Gênica , Hidrólise , Lipase/genética , Ácido Oleico/análise , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genética , Triglicerídeos/metabolismo
16.
JAMA Netw Open ; 7(3): e242375, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38526495

RESUMO

Importance: There is a lack of trials examining the effect of counseling interventions for child, adolescent, and younger adult (CAYA) cancer survivors. Objective: To assess lifestyle habits and the psychosocial situation of CAYAs to determine the efficacy of needs-based interventions in the CARE for CAYA program (CFC-P). Design, Setting, and Participants: The CFC-P was conducted as a multicenter program in 14 German outpatient clinics, mainly university cancer centers. Recruitment began January 1, 2018; a randomized clinical trial was conducted until July 15, 2019; and intervention was continued as a longitudinal cohort study until March 31, 2021. Data preparation was conducted from April 1, 2021, and analysis was conducted from August 14, 2021, to May 31, 2022. Herein, predefined confirmatory analyses pertain to the RCT and descriptive results relate to the overall longitudinal study. Data analysis was based on the full analysis set, which is as close as possible to the intention-to-treat principle. Intervention: A comprehensive assessment determined needs in physical activity, nutrition and psychooncology. Those with high needs participated in 1 to 3 modules. In the RCT, the IG received 5 counseling sessions plus newsletters, while the control group CG received 1 counseling session. Main Outcomes and Measures: The primary outcome was the change in the rate of CAYAs with high needs at 52 weeks. Secondary outcomes were feasibility, modular-specific end points, satisfaction, quality of life, and fatigue. Results: Of 1502 approached CAYAs aged 15 to 39 years, 692 declined participation. Another 22 CAYAs were excluded, resulting in 788 participants. In the randomized clinical trial, 359 CAYAs were randomized (intervention group [IG], n = 183; control group [CG], n = 176), and 274 were followed up. In the RCT, the median age was 25.0 (IQR, 19.9-32.2) years; 226 were female (63.0%) and 133 male (37.0%). After 52 weeks, 120 CAYAs (87.0%) in the IG and 115 (86.5%) in the CG still had a high need in at least 1 module (odds ratio, 1.04; 95% CI, 0.51-2.11; P = .91). Both groups reported reduced needs, improved quality of life, reduced fatigue, and high satisfaction with the CFC-P. Conclusions and Relevance: In this randomized clinical trial, the implementation of a lifestyle program in this cohort was deemed necessary, despite not meeting the primary outcome. The interventions did not alter the rate of high needs. The results may provide guidance for the development of multimodal interventions in the follow-up care of CAYAs. Trial Registration: German Clinical Trial Register: DRKS00012504.


Assuntos
Sobreviventes de Câncer , Neoplasias , Adolescente , Adulto , Criança , Feminino , Masculino , Humanos , Estudos Longitudinais , Sobrevivência , Qualidade de Vida , Estudos de Coortes , Estilo de Vida , Fadiga , Neoplasias/terapia
17.
J Biol Chem ; 287(26): 21806-15, 2012 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-22570489

RESUMO

2000 ribosomes have to be synthesized in yeast every minute. Therefore the fast production of ribosomal proteins, their efficient delivery to the nucleus and correct incorporation into ribosomal subunits are prerequisites for optimal growth rates. Here, we report that the ankyrin repeat protein Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized Rps3 from the cytoplasm into the nucleus where Rps3 is assembled into pre-ribosomal subunits. A yar1 deletion strain displays a similar phenotype as an rps3 mutant strain, showing an accumulation of 20S pre-rRNA and a 40S export defect. The combination of an rps3 mutation with a yar1 deletion leads to an enhancement of these phenotypes, while increased expression of RPS3 suppresses the defects of a yar1 deletion strain. We further show that Yar1 protects Rps3 from aggregation in vitro and increases its solubility in vivo. Our data suggest that Yar1 is a specific chaperone for Rps3, which serves to keep Rps3 soluble until its incorporation into the pre-ribosome.


Assuntos
Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/fisiologia , Transporte Ativo do Núcleo Celular , Núcleo Celular/metabolismo , Chaperoninas/metabolismo , Citoplasma/metabolismo , Deleção de Genes , Regulação Fúngica da Expressão Gênica , Proteínas de Fluorescência Verde/metabolismo , Humanos , Mutação , Proteínas Recombinantes/metabolismo , Schizosaccharomyces/metabolismo , Sacarose/química
18.
Cancers (Basel) ; 15(18)2023 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-37760564

RESUMO

Cancer often causes long-term physical and psychological impairments. Lifestyle modification and nature-based interventions (NBIs) can have a positive impact on patients' quality of life (QOL). This participants-blinded, non-randomized controlled study assessed parameters at weeks 0, 12, and 24, including, as a primary endpoint, QOL in cancer patients on the Functional Assessment of Cancer Therapy-General (FACT-G) at week 12. QOL in breast cancer patients, fatigue, well-being, stress, anxiety/depression, socio-psychological well-being, benefits of nature interaction, insomnia, self-efficacy, mindfulness, and self-compassion were assessed as secondary endpoints. N = 107 cancer patients (96.3% women; 52.5 ± 9.3 years, 80.4% breast cancer) were assigned to either a 12-week nature-based (NDC; n = 56) or conventional (DC; n = 51) oncology day care clinic program, whereby the assignment group was not known to the participants. There was no significant group difference for the primary endpoint. At week 24, QOL, fatigue, mindfulness and self-compassion scores were significantly higher, and at weeks 12 and 24, the insomnia score was significantly lower in NDC compared to DC. In conclusion, this study indicates positive and clinically relevant effects of the program on QOL, fatigue, and psychological parameters. NBIs seem to have a more pronounced effect.

19.
ACS Omega ; 6(9): 6404-6413, 2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33718731

RESUMO

The emergence of a new strain of coronavirus in late 2019, SARS-CoV-2, led to a global pandemic in 2020. This may have been preventable if large scale, rapid diagnosis of active cases had been possible, and this has highlighted the need for more effective and efficient ways of detecting and managing viral infections. In this work, we investigate three different optical techniques for quantifying the binding of recombinant SARS-CoV-2 spike protein to surface-immobilized oligonucleotide aptamers. Biolayer interferometry is a relatively cheap, robust, and rapid method that only requires very small sample volumes. However, its detection limit of 250 nM means that it is not sensitive enough to detect antigen proteins at physiologically relevant levels (sub-pM). Surface plasmon resonance is a more sensitive technique but requires larger sample volumes, takes longer, requires more expensive instrumentation, and only reduces the detection limit to 5 nM. Surface-enhanced Raman spectroscopy is far more sensitive, enabling detection of spike protein to sub-picomolar concentrations. Control experiments performed using scrambled aptamers and using bovine serum albumin as an analyte show that this apta-sensing approach is both sensitive and selective, with no appreciable response observed for any controls. Overall, these proof-of-principle results demonstrate that SERS-based aptasensors hold great promise for development into rapid, point-of-use antigen detection systems, enabling mass testing without any need for reagents or laboratory expertise and equipment.

20.
Clin Transl Immunology ; 10(3): e1261, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33747511

RESUMO

OBJECTIVES: Circulating antibodies are important markers of previous infection and immunity. Questions remain with respect to the durability and functionality of SARS-CoV-2 antibodies. This study explored antibody responses in recovered COVID-19 patients in a setting where the probability of re-exposure is effectively nil, owing to New Zealand's successful elimination strategy. METHODS: A triplex bead-based assay that detects antibody isotype (IgG, IgM and IgA) and subclass (IgG1, IgG2, IgG3 and IgG4) responses against Nucleocapsid (N) protein, the receptor binding domain (RBD) and Spike (S) protein of SARS-CoV-2 was developed. After establishing baseline levels with pre-pandemic control sera (n = 113), samples from PCR-confirmed COVID-19 patients with mild-moderate disease (n = 189) collected up to 8 months post-infection were examined. The relationship between antigen-specific antibodies and neutralising antibodies (NAbs) was explored with a surrogate neutralisation assay that quantifies inhibition of the RBD/hACE-2 interaction. RESULTS: While most individuals had broad isotype and subclass responses to each antigen shortly after infection, only RBD and S protein IgG, as well as NAbs, were relatively stable over the study period, with 99%, 96% and 90% of samples, respectively, having responses over baseline 4-8 months post-infection. Anti-RBD antibodies were strongly correlated with NAbs at all time points (Pearson's r ≥ 0.87), and feasibility of using finger prick sampling to accurately measure anti-RBD IgG was demonstrated. CONCLUSION: Antibodies to SARS-CoV-2 persist for up to 8 months following mild-to-moderate infection. This robust response can be attributed to the initial exposure without immune boosting given the lack of community transmission in our setting.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa