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1.
Sci Rep ; 10(1): 6676, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32317674

RESUMO

Grape-derived proanthocyanidins could act as a protector against various environmental stresses for Saccharomyces cerevisiae during wine fermentation, resulting in the increased physiological activity, fermentation efficiency and improved wine quality. In order to explore the possible protection mechanism of proanthocyanidins globally, RNA-seq analysis for wine yeast AWRI R2 cultivated with 0 g/L (group A), 0.1 g/L (group B), 1.0 g/L (group C) proanthocyanidins were applied in this study. Differentially expressed genes were enriched into six metabolic pathways including vitamin B6, thiamine, amino acids, aminoacyl-tRNA, carbohydrate and steroid based on KEGG enrichment analysis. Four key genes (SNZ2, THI6, THI21 and THI80), participated in the biosynthesis of vitamin B6 and thiamine, were up-regulated significantly in proanthocyanidins treated yeast cells and the gene expression levels were verified by RT-qPCR. Yeast cells supplemented with proanthocyanidins performed increased intracellular levels of vitamin B6 and thiamine and higher cell viability compared to the control group. In addition, the composition of intracellular fatty acids showed an obvious alternation in proanthocyanidins-treated yeast cells, in which the UFAs content increased whereas the SFA content decreased. In general, we provided an indirect protection effect of proanthocyanidins on the yeast cells to alleviate environmental stresses during wine fermentation.


Assuntos
Fermentação/efeitos dos fármacos , Perfilação da Expressão Gênica , Proantocianidinas/farmacologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia , Vinho/microbiologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Ácidos Graxos/metabolismo , Fermentação/genética , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Ontologia Genética , Redes e Vias Metabólicas/efeitos dos fármacos , Redes e Vias Metabólicas/genética , Viabilidade Microbiana/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Tiamina/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Vitamina B 6/metabolismo
2.
J Dairy Sci ; 103(4): 3125-3132, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32037179

RESUMO

The objective of this study was to evaluate the capacity of 6 mycotoxin binders (MTB) to adsorb 3 AA and 4 water-soluble vitamins (WSV). Two experiments were conducted in in vitro conditions to simulate postruminal digestion with pepsin, malic acid, citric acid, acetic acid, and lactic acid at pH 3.0 and intestinal digestion with bile salts and pancreatin extract at pH 6.5. Experiment 1 was conducted with AA, and experiment 2 was conducted with WSV. Within experiment, main factors were the MTB (bentonite, clinoptiolite, sepiolite, montmorillonite, activated carbon, and yeast cell walls), the substrate (AA: Lys, Met, and Thr; WSV: B1, B2, B3, and B6), and the incubation strategy (substrates alone or mixed). Data were analyzed for the effects of main factors and their interactions. In experiment 1, the adsorption average for AA when incubated separately was 44.3%, ranging from 62.4% for Thr by clinoptiolite to 20.0% for Thr by activated carbon. When incubated together, the average adsorption was reduced to 19.9%, suggesting competition among substrates for adsorption. Adsorption ranged from 29.8% for Thr by yeast cell walls to 5.6% for Met by clinoptiolite, but there were significant interactions among MTB and AA. In experiment 2, the average adsorption of WSV when incubated separately or together was 34.1 and 45.1%, respectively, suggesting possible synergies among substrates. When vitamins were incubated separately, adsorption ranged from 90.5% for vitamin B1 to 4.0% for vitamin B3 by montmorillonite. Vitamins B1 (except by yeast cell walls) and B6 (except by bentonite, sepiolite, and montmorillonite) were absorbed the most, and vitamin B3 was absorbed the least (except by activated carbon and yeast cell walls, which were least together with vitamin B2). When vitamins were incubated together, adsorption ranged from 97.0% for vitamin B1 by montmorillonite to 0% for vitamin B2 by activated carbon and vitamin B3 by bentonite. Vitamins B1 by all MTB and B6 by clinoptiolite, sepiolite, and yeast cell walls were the most adsorbed, and vitamin B3 (except by activated carbon and yeast cell wall) was the least absorbed. There were significant interactions among MTB and WSV. Mycotoxin binders have a high degree of adsorption of the AA and WSV tested in in vitro conditions, which may limit their bioavailability. Results also suggest that when substrates were incubated together some interactions for adsorption occurred, which were competitive among AA and synergic among vitamins.


Assuntos
Aminoácidos/metabolismo , Micotoxinas/metabolismo , Complexo Vitamínico B/metabolismo , Adsorção , Animais , Bentonita/metabolismo , Parede Celular , Carvão Vegetal/metabolismo , Feminino , Humanos , Masculino , Gravidez , Riboflavina/metabolismo , Tiamina/metabolismo , Leveduras
3.
Chem Commun (Camb) ; 56(18): 2787-2790, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32025667

RESUMO

Expanding the catalytic repertoire of ribozymes to include vitamin synthesis requires efficient labelling of RNA with the substrate of interest, prior to in vitro selection. For this purpose, we rationally designed and synthesized six GMP-conjugates carrying a synthetic pre-thiamine or biotin precursor and investigated their transcription incorporation properties by T7 RNA polymerase.


Assuntos
RNA Polimerases Dirigidas por DNA/metabolismo , Guanosina Monofosfato/biossíntese , Proteínas Virais/metabolismo , Vitaminas/biossíntese , Biocatálise , Biotina/química , Biotina/metabolismo , Guanosina Monofosfato/química , Estrutura Molecular , Tiamina/química , Tiamina/metabolismo , Vitaminas/química
5.
Nutrients ; 12(1)2020 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-31963892

RESUMO

Background: To measure daily sodium intake in patients on chronic hemodialysis and to compare the intake of nutrients, minerals, trace elements, and vitamins in patients who had a daily sodium intake below or above the value of 1500 mg recommended by the American Heart Association. Methods: Dietary intake was recorded for 3 days by means of 3-day diet diaries in prevalent patients on chronic hemodialysis. Each patient was instructed by a dietitian on how to fill the diary, which was subsequently signed by a next of kin. Results: We studied 127 patients. Mean sodium intake (mg) was 1295.9 ± 812.3. Eighty-seven (68.5%) patients had a daily sodium intake <1500 mg (group 1) and 40 (31.5%) ≥ 1500 mg (group 2). Correlation between daily sodium intake and daily calorie intake was significant (r = 0.474 [0.327 to 0.599]; p < 0.0001). Daily calorie intake (kcal/kg/day) was lower in group 1 (21.1 ± 6.6; p = 0.0001) than in group 2 (27.1 ± 10.4). Correlation between daily sodium intake and daily protein intake was significant (r = 0.530[0.392 to 0.644]; p < 0.0001). The daily protein intake (grams/kg/day) was lower in group 1 (0.823 ± 0.275; p = 0.0003) than in group 2 (1.061 ± 0.419). Daily intake of magnesium, copper, iron, zinc, and selenium was significantly lower in group 1 than in group 2. Daily intake of vitamin A, B2, B3, and C did not differ significantly between group 1 and group 2. Daily intake of vitamin B1 was significantly lower in group 1 than in group 2. Significantly lower was, in group 1 than in group 2, the percentage of patients within the target value with regard to intake of calories (11.5% vs. 37.5%; p = 0.001) and proteins (9.2% vs. 27.5%; p = 0.015) as well as of iron (23% vs. 45%; p = 0.020), zinc (13.8% vs. 53.8%; p = 0.008) and vitamin B1 (8.1% vs. 50%; p < 0.001). Conclusion: A low daily intake of sodium is associated with an inadequately low intake of calorie, proteins, minerals, trace elements, and vitamin B1. Nutritional counselling aimed to reduce the intake of sodium in patients on chronic hemodialysis should not disregard an adequate intake of macro- and micronutrients, otherwise the risk of malnutrition is high.


Assuntos
Proteínas na Dieta/administração & dosagem , Ingestão de Energia , Ferro na Dieta/administração & dosagem , Falência Renal Crônica/terapia , Recomendações Nutricionais , Diálise Renal , Sódio na Dieta/administração & dosagem , Tiamina/administração & dosagem , Zinco/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Proteínas na Dieta/metabolismo , Feminino , Humanos , Ferro na Dieta/metabolismo , Itália , Falência Renal Crônica/metabolismo , Falência Renal Crônica/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Sódio na Dieta/metabolismo , Tiamina/metabolismo , Fatores de Tempo , Zinco/metabolismo
7.
PLoS One ; 15(1): e0227201, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31895939

RESUMO

The eastern Baltic cod (Gadus morhua) population has been decreasing in the Baltic Sea for at least 30 years. Condition indices of the Baltic cod have decreased, and previous studies have suggested that this might be due to overfishing, predation, lower dissolved oxygen or changes in salinity. However, numerous studies from the Baltic Sea have demonstrated an ongoing thiamine deficiency in several animal classes, both invertebrates and vertebrates. The thiamine status of the eastern Baltic cod was investigated to determine if thiamine deficiency might be a factor in ongoing population declines. Thiamine concentrations were determined by chemical analyses of thiamine, thiamine monophosphate and thiamine diphosphate (combined SumT) in the liver using high performance liquid chromatography. Biochemical analyses measured the activity of the thiamine diphosphate-dependent enzyme transketolase to determine the proportion of apoenzymes in both liver and brain tissue. These biochemical analyses showed that 77% of the cod were thiamine deficient in the liver, of which 13% had a severe thiamine deficiency (i.e. 25% transketolase enzymes lacked thiamine diphosphate). The brain tissue of 77% of the cod showed thiamine deficiency, of which 64% showed severe thiamine deficiency. The thiamine deficiency biomarkers were investigated to find correlations to different biological parameters, such as length, weight, otolith weight, age (annuli counting) and different organ weights. The results suggested that thiamine deficiency increased with age. The SumT concentration ranged between 2.4-24 nmol/g in the liver, where the specimens with heavier otoliths had lower values of SumT (P = 0.0031). Of the cod sampled, only 2% of the specimens had a Fulton's condition factor indicating a healthy specimen, and 49% had a condition factor below 0.8, indicating poor health status. These results, showing a severe thiamine deficiency in eastern Baltic cod from the only known area where spawning presently occurs for this species, are of grave concern.


Assuntos
Doenças dos Peixes/metabolismo , Gadus morhua/metabolismo , Deficiência de Tiamina/veterinária , Tiamina/metabolismo , Animais , Encéfalo/metabolismo , Feminino , Fígado/metabolismo , Masculino , Tiamina/análise , Deficiência de Tiamina/metabolismo
8.
PLoS One ; 15(1): e0227714, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31917814

RESUMO

Vitamin B1 (thiamin) deficiency is an issue periodically affecting a wide range of taxa worldwide. In aquatic pelagic systems, thiamin is mainly produced by bacteria and phytoplankton and is transferred to fish and birds via zooplankton, but there is no general consensus on when or why this transfer is disrupted. We focus on the occurrence in salmon (Salmo salar) of a thiamin deficiency syndrome (M74), the incidence of which is highly correlated among populations derived from different spawning rivers. Here, we show that M74 in salmon is associated with certain large-scale abiotic changes in the main common feeding area of salmon in the southern Baltic Sea. Years with high M74 incidence were characterized by stagnant periods with relatively low salinity and phosphate and silicate concentrations but high total nitrogen. Consequently, there were major changes in phytoplankton and zooplankton, with, e.g., increased abundances of Cryptophyceae, Dinophyceae, Diatomophyceae and Euglenophyceae and Acartia spp. during high M74 incidence years. The prey fish communities also had increased stocks of both herring and sprat in these years. Overall, this suggests important changes in the entire food web structure and nutritional pathways in the common feeding period during high M74 incidence years. Previous research has emphasized the importance of the abundance of planktivorous fish for the occurrence of M74. By using this 27-year time series, we expand this analysis to the entire ecosystem and discuss potential mechanisms inducing thiamin deficiency in salmon.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Cadeia Alimentar , Salmo salar/fisiologia , Deficiência de Tiamina/veterinária , Animais , Monitorização de Parâmetros Ecológicos/tendências , Feminino , Incidência , Oceanos e Mares , Fitoplâncton/química , Tiamina/metabolismo , Deficiência de Tiamina/epidemiologia , Deficiência de Tiamina/etiologia , Zooplâncton/química
9.
Am J Clin Nutr ; 111(1): 110-121, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31764942

RESUMO

BACKGROUND: Transporter-mediated drug-nutrient interactions have the potential to cause serious adverse events. However, unlike drug-drug interactions, these drug-nutrient interactions receive little attention during drug development. The clinical importance of drug-nutrient interactions was highlighted when a phase III clinical trial was terminated due to severe adverse events resulting from potent inhibition of thiamine transporter 2 (ThTR-2; SLC19A3). OBJECTIVE: In this study, we tested the hypothesis that therapeutic drugs inhibit the intestinal thiamine transporter ThTR-2, which may lead to thiamine deficiency. METHODS: For this exploration, we took a multifaceted approach, starting with a high-throughput in vitro primary screen to identify inhibitors, building in silico models to characterize inhibitors, and leveraging real-world data from electronic health records to begin to understand the clinical relevance of these inhibitors. RESULTS: Our high-throughput screen of 1360 compounds, including many clinically used drugs, identified 146 potential inhibitors at 200 µM. Inhibition kinetics were determined for 28 drugs with half-maximal inhibitory concentration (IC50) values ranging from 1.03 µM to >1 mM. Several oral drugs, including metformin, were predicted to have intestinal concentrations that may result in ThTR-2-mediated drug-nutrient interactions. Complementary analysis using electronic health records suggested that thiamine laboratory values are reduced in individuals receiving prescription drugs found to significantly inhibit ThTR-2, particularly in vulnerable populations (e.g., individuals with alcoholism). CONCLUSIONS: Our comprehensive analysis of prescription drugs suggests that several marketed drugs inhibit ThTR-2, which may contribute to thiamine deficiency, especially in at-risk populations.


Assuntos
Interações Alimento-Droga , Proteínas de Membrana Transportadoras/química , Preparações Farmacêuticas/química , Transporte Biológico/efeitos dos fármacos , Células HEK293 , Humanos , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Preparações Farmacêuticas/metabolismo , Medicamentos sob Prescrição/química , Medicamentos sob Prescrição/metabolismo , Tiamina/metabolismo
10.
Diab Vasc Dis Res ; 17(1): 1479164119878427, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31726874

RESUMO

Thiamine prevents high glucose-induced damage in microvasculature, and progression of retinopathy and nephropathy in diabetic animals. Impaired thiamine availability causes renal damage in diabetic patients. Two single-nucleotide polymorphisms in SLC19A3 locus encoding for thiamine transporter 2 are associated with absent/minimal diabetic retinopathy and nephropathy despite long-term type 1 diabetes. We investigated the involvement of thiamine transporter 1 and thiamine transporter 2, and their transcription factor specificity protein 1, in high glucose-induced damage and altered thiamine availability in cells of the inner blood-retinal barrier. Human endothelial cells, pericytes and Müller cells were exposed to hyperglycaemic-like conditions and/or thiamine deficiency/over-supplementation in single/co-cultures. Expression and localization of thiamine transporter 1, thiamine transporter 2 and transcription factor specificity protein 1 were evaluated together with intracellular thiamine concentration, transketolase activity and permeability to thiamine. The effects of thiamine depletion on cell function (viability, apoptosis and migration) were also addressed. Thiamine transporter 2 and transcription factor specificity protein 1 expression were modulated by hyperglycaemic-like conditions. Transketolase activity, intracellular thiamine and permeability to thiamine were decreased in cells cultured in thiamine deficiency, and in pericytes in hyperglycaemic-like conditions. Thiamine depletion reduced cell viability and proliferation, while thiamine over-supplementation compensated for thiamine transporter 2 reduction by restoring thiamine uptake and transketolase activity. High glucose and reduced thiamine determine impairment in thiamine transport inside retinal cells and through the inner blood-retinal barrier. Thiamine transporter 2 modulation in our cell models suggests its major role in thiamine transport in retinal cells and its involvement in high glucose-induced damage and impaired thiamine availability.


Assuntos
Retinopatia Diabética/metabolismo , Células Endoteliais/efeitos dos fármacos , Células Ependimogliais/efeitos dos fármacos , Glucose/toxicidade , Proteínas de Membrana Transportadoras/metabolismo , Pericitos/efeitos dos fármacos , Vasos Retinianos/efeitos dos fármacos , Tiamina/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Microambiente Celular , Técnicas de Cocultura , Retinopatia Diabética/genética , Retinopatia Diabética/patologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Células Ependimogliais/metabolismo , Células Ependimogliais/patologia , Humanos , Proteínas de Membrana Transportadoras/genética , Pericitos/metabolismo , Pericitos/patologia , Vasos Retinianos/metabolismo , Vasos Retinianos/patologia , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/metabolismo , Transcetolase/metabolismo
11.
Appl Environ Microbiol ; 86(3)2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31704686

RESUMO

Thiamine is a vitamin that functions as a cofactor for key enzymes in carbon and energy metabolism in all living cells. While most plants, fungi, and bacteria can synthesize thiamine de novo, the oleaginous yeast Yarrowia lipolytica cannot. In this study, we used proteomics together with physiological characterization to elucidate key metabolic processes influenced and regulated by thiamine availability and to identify the genetic basis of thiamine auxotrophy in Y. lipolytica Specifically, we found that thiamine depletion results in decreased protein abundance for the lipid biosynthesis pathway and energy metabolism (i.e., ATP synthase), leading to the negligible growth and poor sugar assimilation observed in our study. Using comparative genomics, we identified the missing 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate synthase (THI13) gene for the de novo thiamine biosynthesis in Y. lipolytica and discovered an exceptional promoter, P3, that exhibits strong activation and tight repression by low and high thiamine concentrations, respectively. Capitalizing on the strength of our thiamine-regulated promoter (P3) to express the missing gene from Saccharomyces cerevisiae (scTHI13), we engineered a thiamine-prototrophic Y. lipolytica strain. By comparing this engineered strain to the wild-type strain, we revealed the tight relationship between thiamine availability and lipid biosynthesis and demonstrated enhanced lipid production with thiamine supplementation in the engineered thiamine-prototrophic Y. lipolytica strain.IMPORTANCE Thiamine plays a crucial role as an essential cofactor for enzymes involved in carbon and energy metabolism in all living cells. Thiamine deficiency has detrimental consequences for cellular health. Yarrowia lipolytica, a nonconventional oleaginous yeast with broad biotechnological applications, is a native thiamine auxotroph whose affected cellular metabolism is not well understood. Therefore, Y. lipolytica is an ideal eukaryotic host for the study of thiamine metabolism, especially because mammalian cells are also thiamine auxotrophic and thiamine deficiency is implicated in several human diseases. This study elucidates the fundamental effects of thiamine deficiency on cellular metabolism in Y. lipolytica and identifies genes and novel thiamine-regulated elements that eliminate thiamine auxotrophy in Y. lipolytica Furthermore, the discovery of thiamine-regulated elements enables the development of thiamine biosensors with useful applications in synthetic biology and metabolic engineering.


Assuntos
Proteínas Fúngicas/metabolismo , Proteoma , Deficiência de Tiamina/metabolismo , Tiamina/metabolismo , Yarrowia/metabolismo
12.
Environ Sci Pollut Res Int ; 27(1): 941-953, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31820241

RESUMO

Although thiamine (THI) and hydrogen sulphide (H2S) both have widely been tested in the plant under stress conditions, cross talk between THI and H2S in the acquisition of cadmium (Cd) stress tolerance needs to be studied. So, an experiment was designed to study the participation of endogenous H2S in THI-induced tolerance to Cd stress in strawberry plants. A foliar spray solution containing THI (50 mg L-1) was sprayed once a week for 4 weeks to the foliage of strawberry plants under Cd stress (1.0 mM CdCl2). The plant dry weight, total chlorophyll, maximum efficiency of PSII (Fv/Fm), leaf potassium (K+) and calcium (Ca2+) as well as leaf water potential were significantly reduced, but the proline, ascorbate (AsA), glutathione (GSH), malondialdehyde (MDA), hydrogen peroxide (H2O2), electron leakage (EL) and leaf Cd as well as endogenous H2S and NO were increased by Cd stress. Application of THI alleviated the oxidative damage due to Cd stress and caused a further elevation in endogenous H2S and NO contents. Remarkably, THI-induced Cd stress tolerance was further improved by addition of sodium hydrosulfide (0.2 mM NaHS), a H2S donor. To get an insight whether or not H2S involved in THI-improved tolerance to Cd toxicity in strawberry plants, an H2S scavenger, hypotaurine (HT 0.1 mM), was supplied along with the THI and NaHS treatments. THI-improved tolerance to Cd stress was partly reversed by HT by reducing leaf H2S and NO to the level and above of these under Cd toxicity alone, respectively. The findings evidently showed that leaf H2S and NO together involved in induced tolerance to Cd toxicity by THI. This evidence was also proved by the partly increases in MDA and H2O2 and decreases in antioxidant defence enzymes such as superoxide dismutase, catalase and peroxidase as well as the plant biomass and partly enhanced leaf Cd content by exogenous applied HT along with THI.


Assuntos
Cádmio/toxicidade , Fragaria/efeitos dos fármacos , Sulfeto de Hidrogênio/metabolismo , Poluentes do Solo/toxicidade , Tiamina/metabolismo , Antioxidantes/metabolismo , Ácido Ascórbico , Catalase/metabolismo , Clorofila/metabolismo , Fragaria/metabolismo , Glutationa/metabolismo , Peróxido de Hidrogênio , Malondialdeído , Oxirredução , Peroxidases , Folhas de Planta/metabolismo , Sulfetos , Superóxido Dismutase/metabolismo
13.
Food Chem ; 302: 125365, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31442703

RESUMO

Retention of labile vitamins such as thiamine (vitamin B1) in NASA spaceflight foods intended for extended-duration missions is critical for the health of the crew. In this study, the degradation kinetics of thiamine in three NASA spaceflight foods (brown rice, split pea soup, BBQ beef brisket) during storage was determined for the first time, using an interactive isothermal model developed by our group. Results showed that brown rice and split pea soup demonstrated resistance to thiamine degradation, while thiamine in beef brisket was less stable. Model-predicted thiamine retention in brown rice stored at 20 °C for 720 days was 55% of the original thiamine content after thermal processing, 42% for split pea soup, and 3% for beef brisket. Water activity, moisture content, and pH differences did not sufficiently explain the variation in the degradation kinetics of thiamine among these foods.


Assuntos
Armazenamento de Alimentos , Alimentos , Tiamina/metabolismo , Análise de Alimentos/métodos , Concentração de Íons de Hidrogênio , Cinética , Oryza , Carne Vermelha , Voo Espacial , Temperatura , Tiamina/análise , Estados Unidos , United States National Aeronautics and Space Administration , Água/química
14.
G3 (Bethesda) ; 10(1): 321-331, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31732505

RESUMO

Regulatory networks often converge on very similar cis sequences to drive transcriptional programs due to constraints on what transcription factors are present. To determine the role of constraint loss on cis element evolution, we examined the recent appearance of a thiamine starvation regulated promoter in Candida glabrata This species lacks the ancestral transcription factor Thi2, but still has the transcription factor Pdc2, which regulates thiamine starvation genes, allowing us to determine the effect of constraint change on a new promoter. We identified two different cis elements in C. glabrata - one present in the evolutionarily recent gene called CgPMU3, and the other element present in the other thiamine (THI) regulated genes. Reciprocal swaps of the cis elements and incorporation of the S. cerevisiae Thi2 transcription factor-binding site into these promoters demonstrate that the two elements are functionally different from one another. Thus, this loss of an imposed constraint on promoter function has generated a novel cis sequence, suggesting that loss of trans constraints can generate a non-convergent pathway with the same output.


Assuntos
Candida glabrata/genética , Regulação Fúngica da Expressão Gênica , Regiões Promotoras Genéticas , Tiamina/metabolismo , Candida glabrata/metabolismo , Evolução Molecular , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
15.
PLoS One ; 14(12): e0224984, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31800573

RESUMO

Changes in eating behavior of adolescents are associated with high consumption of processed and ultra-processed foods. This study evaluated the association between these foods and the prevalence of inadequate micronutrient intake in adolescents. A cross-sectional study was conducted with 444 adolescents from public schools in the city of Natal, northeastern Brazil. The adolescents' habitual food consumption was evaluated using two 24-hour dietary recalls. Foods were categorized according to the degree of processing (processed and ultra-processed) and distributed into energy quartiles, using the NOVA classification system. Inadequacies in micronutrient intake were assessed using the estimated average requirement (EAR) as the cutoff point. Multivariate logistic regression models were used to estimate the relationship between energy percentage from processed and ultra-processed foods and prevalence of inadequate micronutrient intake. The mean (Standard Deviation (SD)) consumption of total energy from processed foods ranged from 5.8% (1.7%) in Q1 to 20.6% (2.9%) in Q4, while the mean consumption of total energy from ultra-processed foods ranged from 21.4% (4.9%) in Q1 to 61.5% (11.7%) in Q4. The rates of inadequate intake of vitamin D, vitamin E, folate, calcium, and selenium were above 80% for both sexes across all age groups. Energy consumption from processed foods was associated with higher prevalence of inadequate selenium intake (p < 0.01) and lower prevalence of inadequate vitamin B1 intake (p = 0.04). Energy consumption from ultra-processed foods was associated with lower prevalence of inadequate zinc and vitamin B1 intake (p < 0.01 and p = 0.03, respectively). An increase in the proportion of energy obtained from processed and ultra-processed foods may reflect higher prevalence of inadequate selenium intake and lower prevalence of vitamin B1 and zinc inadequacy.


Assuntos
Ingestão de Energia , Fast Foods/efeitos adversos , Selênio/metabolismo , Deficiência de Tiamina/epidemiologia , Tiamina/metabolismo , Zinco/metabolismo , Adolescente , Fenômenos Fisiológicos da Nutrição do Adolescente , Brasil , Criança , Fast Foods/estatística & dados numéricos , Feminino , Humanos , Masculino , Recomendações Nutricionais , Instituições Acadêmicas/estatística & dados numéricos , Selênio/deficiência , População Urbana/estatística & dados numéricos , Zinco/deficiência
17.
PLoS Biol ; 17(10): e3000512, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31658248

RESUMO

Endocytosis of membrane proteins in yeast requires α-arrestin-mediated ubiquitylation by the ubiquitin ligase Rsp5. Yet, the diversity of α-arrestin targets studied is restricted to a small subset of plasma membrane (PM) proteins. Here, we performed quantitative proteomics to identify new targets of 12 α-arrestins and gained insight into the diversity of pathways affected by α-arrestins, including the cell wall integrity pathway and PM-endoplasmic reticulum contact sites. We found that Art2 is the main regulator of substrate- and stress-induced ubiquitylation and endocytosis of the thiamine (vitamin B1) transporters: Thi7, nicotinamide riboside transporter 1 (Nrt1), and Thi72. Genetic screening allowed for the isolation of transport-defective Thi7 mutants, which impaired thiamine-induced endocytosis. Coexpression of inactive mutants with wild-type Thi7 revealed that both transporter conformation and transport activity are important to induce endocytosis. Finally, we provide evidence that Art2 mediated Thi7 endocytosis is regulated by the target of rapamycin complex 1 (TORC1) and requires the Sit4 phosphatase but is not inhibited by the Npr1 kinase.


Assuntos
Arrestinas/genética , Proteínas de Membrana Transportadoras/genética , Proteínas de Transporte de Nucleosídeos/genética , Processamento de Proteína Pós-Traducional , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Tiamina/metabolismo , Arrestinas/metabolismo , Membrana Celular/efeitos dos fármacos , Membrana Celular/genética , Membrana Celular/metabolismo , Parede Celular/efeitos dos fármacos , Parede Celular/genética , Parede Celular/metabolismo , Endocitose/genética , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Regulação Fúngica da Expressão Gênica , Proteínas de Membrana Transportadoras/metabolismo , Modelos Moleculares , Mutação , Proteínas de Transporte de Nucleosídeos/metabolismo , Ligação Proteica , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Estrutura Secundária de Proteína , Proteômica/métodos , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Transdução de Sinais , Tiamina/farmacologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Complexos Ubiquitina-Proteína Ligase/genética , Complexos Ubiquitina-Proteína Ligase/metabolismo , Ubiquitinação
18.
Proc Natl Acad Sci U S A ; 116(44): 22219-22228, 2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31611373

RESUMO

Horizontal acquisition of bacterial genes is presently recognized as an important contribution to the adaptation and evolution of eukaryotic genomes. However, the mechanisms underlying expression and consequent selection and fixation of the prokaryotic genes in the new eukaryotic setting are largely unknown. Here we show that genes composing the pathway for the synthesis of the essential vitamin B1 (thiamine) were lost in an ancestor of a yeast lineage, the Wickerhamiella/Starmerella (W/S) clade, known to harbor an unusually large number of genes of alien origin. The thiamine pathway was subsequently reassembled, at least twice, by multiple HGT events from different bacterial donors involving both single genes and entire operons. In the W/S-clade species Starmerella bombicola we obtained direct genetic evidence that all bacterial genes of the thiamine pathway are functional. The reconstructed pathway is composed by yeast and bacterial genes operating coordinately to scavenge thiamine derivatives from the environment. The adaptation of the newly acquired operons to the eukaryotic setting involved a repertoire of mechanisms until now only sparsely documented, namely longer intergenic regions, post-horizontal gene transfer (HGT) gene fusions fostering coordinated expression, gene relocation, and possibly recombination generating mosaic genes. The results provide additional evidence that HGT occurred recurrently in this yeast lineage and was crucial for the reestablishment of lost functions and that similar mechanisms are used across a broad range of eukaryotic microbes to promote adaptation of prokaryotic genes to their new environment.


Assuntos
Transferência Genética Horizontal , Genes Bacterianos , Óperon , Saccharomycetales/genética , Tiamina/genética , Bactérias/genética , Tiamina/metabolismo
19.
Biochemistry (Mosc) ; 84(8): 829-850, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31522667

RESUMO

Thiamine (vitamin B1) is a precursor of the well-known coenzyme of central metabolic pathways thiamine diphosphate (ThDP). Highly intense glucose oxidation in the brain requires ThDP-dependent enzymes, which determines the critical significance of thiamine for neuronal functions. However, thiamine can also act through the non-coenzyme mechanisms. The well-known facilitation of acetylcholinergic neurotransmission upon the thiamine and acetylcholine co-release into the synaptic cleft has been supported by the discovery of thiamine triphosphate (ThTP)-dependent phosphorylation of the acetylcholine receptor-associated protein rapsyn, and thiamine interaction with the TAS2R1 receptor, resulting in the activation of synaptic ion currents. The non-coenzyme regulatory binding of thiamine compounds has been demonstrated for the transcriptional regulator p53, poly(ADP-ribose) polymerase, prion protein PRNP, and a number of key metabolic enzymes that do not use ThDP as a coenzyme. The accumulated data indicate that the molecular mechanisms of the neurotropic action of thiamine are far broader than it has been originally believed, and closely linked to the metabolism of thiamine and its derivatives in animals. The significance of this topic has been illustrated by the recently established competition between thiamine and the antidiabetic drug metformin for common transporters, which can be the reason for the thiamine deficiency underlying metformin side effects. Here, we also discuss the medical implications of the research on thiamine, including the role of thiaminases in thiamine reutilization and biosynthesis of thiamine antagonists; molecular mechanisms of action of natural and synthetic thiamine antagonists, and biotransformation of pharmacological forms of thiamine. Given the wide medical application of thiamine and its synthetic forms, these aspects are of high importance for medicine and pharmacology, including the therapy of neurodegenerative diseases.


Assuntos
Hipoglicemiantes/metabolismo , Metformina/metabolismo , Tiamina/análogos & derivados , Tiamina/metabolismo , Complexo Vitamínico B/metabolismo , Animais , Encéfalo/metabolismo , Coenzimas , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Metformina/administração & dosagem , Metformina/efeitos adversos , Camundongos , Fosforilação , Transporte Proteico/fisiologia , Ratos , Tiamina/efeitos adversos , Tiamina/farmacologia , Deficiência de Tiamina/etiologia , Deficiência de Tiamina/prevenção & controle , Tiamina Pirofosfato/metabolismo , Complexo Vitamínico B/efeitos adversos , Complexo Vitamínico B/farmacologia
20.
Lett Appl Microbiol ; 69(5): 379-384, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31513285

RESUMO

The impacts of thiamin and pyridoxine along with YAN on alcoholic fermentation and hydrogen sulphide production by Saccharomyces cerevisiae were studied. Using a synthetic grape juice medium, three fermentation trials were conducted; (i) 2 × 3 factorial design with thiamin (0, 0·2, or 0·5 mg l-1 ) and YAN (60 or 250 mg l-1 ) as variables, (ii) 2 × 3 factorial design with pyridoxine (0, 0·25, or 0·5 mg l-1 ) and YAN (60 or 250 mg l-1 ) as variables, and (iii) 3 × 3 factorial design with thiamin (0, 0·2 or 0·5 mg l-1 ) and pyridoxine (0, 0·25 or 0·5 mg l-1 ) as variables in media containing 60 mg l-1 YAN. Although the progress of fermentations was affected by thiamin or pyridoxine, YAN had a larger impact than either vitamin. H2 S production was significantly lower with increasing amounts of thiamin in those fermentations under low YAN (60 mg l-1 ) while even lower amounts (<30 µg l-1 ) were produced under high YAN (250 mg l-1 ) with or without the vitamin. The highest amounts of H2 S were synthesized in those fermentations without any pyridoxine (>110 µg l-1 ), with the lowest production in media with pyridoxine and high YAN (<20 µg l-1 ). SIGNIFICANCE AND IMPACT OF THE STUDY: Concentrations of thiamin, pyridoxine and yeast assimilable nitrogen (YAN) influenced the synthesis of hydrogen sulphide (H2 S) by Saccharomyces cerevisiae in a synthetic grape juice medium. With a few exceptions, an increase in the concentration of either vitamin or YAN resulted in less H2 S released. This is the first report to demonstrate that both thiamin and pyridoxine along with YAN affected H2 S production, emphasizing the need to assess yeast nutrients to lower risks of off-odours during fermentation.


Assuntos
Sucos de Frutas e Vegetais/análise , Sulfeto de Hidrogênio/metabolismo , Saccharomyces cerevisiae/metabolismo , Tiamina/análise , Vitamina B 6/análise , Vitis/química , Meios de Cultura/análise , Meios de Cultura/síntese química , Meios de Cultura/metabolismo , Fermentação , Sucos de Frutas e Vegetais/microbiologia , Sulfeto de Hidrogênio/análise , Odorantes/análise , Piridoxina/análise , Piridoxina/metabolismo , Tiamina/metabolismo , Vitamina B 6/metabolismo , Vitis/microbiologia
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