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1.
Food Res Int ; 175: 113688, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38129031

RESUMO

Bos taurus indicus bulls are very susceptible to pre-slaughter stress, which directly impacts the decline in muscle pH, leading to darker meat. The aim was to investigate the effect of succinate and atmosphere on the color stability of Nellore (Bos taurus indicus) Longissimus lumborum steaks classified by ultimate pH (pHu): normal pHu (5.40 ≤ pHu ≤ 5.79) and high pHu (pHu ≥ 5.80). The experimental treatment systems were: (i) vacuum packaging without succinate injection, (ii) HiOx-MAP (80 % O2 + 20 % CO2), and (iii) HiOx-MAP (80 % O2 + 20 % CO2) enhanced with sodium succinate injection (pH 5.4). Steaks from all treatment systems were stored at 4 °C for 14 days and tested for instrumental color, myoglobin content, oxygen consumption (OC), metmyoglobin-reducing activity (MRA), lipid oxidation, and microbiological analysis. High and normal pHu vacuum-packaged steaks exhibited greater color stability due to higher MRA. High and normal pHu steaks packaged with HiOx-MAP or HiOx-MAP enhanced with succinate showed improved color due to lower deoxymyoglobin content (%DMb) and OC up to the eighth day of storage. Still, succinate injection promoted increased (P < 0.05) lipid oxidation in normal pHu steaks and reduced MRA after 14 days. These findings emphasize the intricate interplay between pHu and packaging systems on Bos taurus indicus meat quality. Further research in this area could contribute to a better understanding of meat color abnormalities and provide insights into potential meat preservation and enhancement strategies.


Assuntos
Embalagem de Alimentos , Ácido Succínico , Bovinos , Masculino , Animais , Dióxido de Carbono , Carne/análise , Metamioglobina , Succinatos , Concentração de Íons de Hidrogênio , Lipídeos
2.
J Mater Chem B ; 11(20): 4556-4571, 2023 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-37161773

RESUMO

Polyethyleneimine (PEI) derivatives substituted by lactose, succinic acid or alkyl domains were evaluated as nonviral gene delivery vectors towards balancing gene transfection and cytotoxicity. The investigations were focused on pDNA transfection into arising retinal pigment epithelia (ARPE-19) and human hepatocellular carcinoma (HepG2) cell lines. The first mentioned cell line was chosen as motivated by the non-negligible number of ocular disorders linked to gene aberrations, whereas the second one is a cell line overexpressing the asialoglycoprotein receptor (ASGP-R), which can bind to galactose residues. The presence of short alkyl domains (C4 and C6), and particularly the succinylation of the PEI chains, improved the biological outputs of the gene vectors. The presence of hydrophobic units possibly enhances lytic activity, whereas the incorporation of succinic acid slightly reduces polymer-DNA interaction strength, thereby enabling more efficient intracellular unpacking and cargo release. Succinylation is also supposed to decrease cytotoxicity and avoid protein adsorption to the polyplexes. The presence of long carbon chains (for instance, C12) nevertheless, results in higher levels of cytotoxicity and respective lower transfection rates. The sugar-decorated polyplexes are overall less cytotoxic, but the presence of lactose moieties also leads to larger polyplexes and notably weak polymer-DNA binding, which compromise the transfection efficiency. Yet, along with the presence of short lytic alkyl domains, the double-substitution of PEI synergistically boosts gene transfection probably due to the uptake of higher DNA and polymer amounts without cell damage. Overall, the experimental data suggest that ocular and hepatic gene therapies may be potentialized by fine-tuning the hydrophobic-to-hydrophilic balance, and succinic acid is a favorable motif for the modification of PEI.


Assuntos
Neoplasias Hepáticas , Ácidos Nucleicos , Humanos , Polietilenoimina/química , Plasmídeos , Ácido Succínico , Lactose , Transfecção , DNA/genética , DNA/química , Neoplasias Hepáticas/genética
3.
Am J Physiol Endocrinol Metab ; 324(3): E226-E240, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36724126

RESUMO

Obesity is one of the leading noncommunicable diseases in the world. Despite intense efforts to develop strategies to prevent and treat obesity, its prevalence continues to rise worldwide. A recent study has shown that the tricarboxylic acid intermediate succinate increases body energy expenditure by promoting brown adipose tissue thermogenesis through the activation of uncoupling protein-1; this has generated interest surrounding its potential usefulness as an approach to treat obesity. It is currently unknown how succinate impacts brown adipose tissue protein expression, and how exogenous succinate impacts body mass reduction promoted by a drug approved to treat human obesity, the glucagon-like-1 receptor agonist, liraglutide. In the first part of this study, we used bottom-up shotgun proteomics to determine the acute impact of exogenous succinate on the brown adipose tissue. We show that succinate rapidly affects the expression of 177 brown adipose tissue proteins, which are mostly associated with mitochondrial structure and function. In the second part of this study, we performed a short-term preclinical pharmacological intervention, treating diet-induced obese mice with a combination of exogenous succinate and liraglutide. We show that the combination was more efficient than liraglutide alone in promoting body mass reduction, food energy efficiency reduction, food intake reduction, and an increase in body temperature. Using serum metabolomics analysis, we showed that succinate, but not liraglutide, promoted a significant increase in the blood levels of several medium and long-chain fatty acids. In conclusion, exogenous succinate promotes rapid changes in brown adipose tissue mitochondrial proteins, and when used in association with liraglutide, increases body mass reduction.NEW & NOTEWORTHY Exogenous succinate induces major changes in brown adipose tissue protein expression affecting particularly mitochondrial respiration and structural proteins. When given exogenously in drinking water, succinate mitigates body mass gain in a rodent model of diet-induced obesity; in addition, when given in association with the glucagon-like peptide-1 receptor agonist, liraglutide, succinate increases body mass reduction promoted by liraglutide alone.


Assuntos
Tecido Adiposo Marrom , Liraglutida , Animais , Camundongos , Tecido Adiposo Marrom/metabolismo , Metabolismo Energético , Liraglutida/farmacologia , Liraglutida/uso terapêutico , Obesidade/metabolismo , Proteoma/metabolismo , Ácido Succínico/farmacologia , Ácido Succínico/metabolismo , Ácido Succínico/uso terapêutico , Termogênese , Proteína Desacopladora 1/metabolismo
4.
Int Forum Allergy Rhinol ; 13(8): 1525-1534, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36565436

RESUMO

BACKGROUND: Succinate, although most famous for its role in the Krebs cycle, can be released extracellularly as a signal of cellular distress, particularly in situations of metabolic stress and inflammation. Solitary chemosensory cells (SCCs) express SUCNR1, the succinate receptor, and modulate type 2 inflammatory responses in helminth and protozoal infections in the small intestine. SCCs are the dominant epithelial source of interleukin-25, as well as an important source of cysteinyl leukotrienes in the airway, and have been implicated as upstream agents in type 2 inflammation in chronic rhinosinusitis (CRS) and asthma. METHODS: In this study, we used scRNAseq analysis, live cell imaging of intracellular calcium from primary sinonasal air-liquid interface (ALI) cultures from 1 donor, and measure antimicrobial peptide release from 5 donors to demonstrate preliminary evidence suggesting that succinate can act as a stimulant of SCCs in the human sinonasal epithelium. RESULTS: Results from scRNAseq analysis show that approximately 10% of the SCC/ionocyte cluster of cells expressed SUCNR1 as well as a small population of immune cells. Using live cell imaging of intracellular calcium, we also demonstrate that clusters of cells on primary sinonasal ALI cultures initiated calcium-mediated signaling in response to succinate stimulation. Furthermore, we present evidence that primary sinonasal ALI cultures treated with succinate had increased levels of apical beta-defensin 2, an antimicrobial peptide, compared to treatment with a control solution. CONCLUSION: Overall, these findings demonstrate the need for further investigation into the activation of the sinonasal epithelium by succinate in the pathogenesis of CRS.


Assuntos
Rinite , Sinusite , Humanos , Ácido Succínico/metabolismo , Cálcio/metabolismo , Epitélio/metabolismo , Doença Crônica , Inflamação , Peptídeos Antimicrobianos , Células Epiteliais/metabolismo
5.
Environ Sci Pollut Res Int ; 29(53): 79954-79976, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35190982

RESUMO

This study reports the use of multivariate tools to optimize the synthesis of a new agricultural-based biosorbent derived from sugarcane bagasse (SB) for the removal of Cd(II) and Pb(II) from aqueous solutions, as well as to optimize the process of desorption of these ions from the spent biosorbent using an acidic solution. The effects of the reaction parameters temperature (T), time (t), and the ratio of 1,2,3,4-butanetetracarboxylic acid dianhydride (BTCAD) to raw SB (wBTCAD wraw SB-1) on the chemical modification of raw SB with BTCAD and on the equilibrium adsorption capacity (qe) for Cd(II) and Pb(II) were investigated by application of a 23 Doehlert experimental design (DED), followed by optimization using a statistical desirability tool to produce the best adsorbent in terms of performance and cost. The best reaction condition was wBTCAD wraw SB-1 of 4.0 g g-1, t of 1 h, and T of 70 ºC. The optimal synthesis condition resulted in a modified sugarcane bagasse (MSB) that provided qe values for Cd(II) and Pb(II) of 0.50 and 0.61 mmol g-1, respectively, obtained under the following conditions: 0.311 mmol Cd(II) L-1, 0.632 mmol Pb(II) L-1, pH 5.0, 4 h, 0.2 g L-1 MSB, 130 rpm, and 25 °C. The desorption of Cd(II) and Pb(II) from MSB was investigated by a 22 DED, with optimization using the desirability tool to obtain the best desorption condition in terms of HNO3 solution concentration ([Formula: see text]) and t. The desorption efficiencies for Cd(II) and Pb(II) were 90 ± 4% and 88 ± 3%, respectively, obtained using 0.7 mol L-1 HNO3, t of 42 min, and 1.0 g L-1 MSB-M(II) (M = Pb or Cd). Infrared spectroscopy was used to investigate the natures of the interactions involved in the adsorption of Cd(II) and Pb(II) on MSB, as well as possible changes in the chemical structure of MSB after desorption. The synthesis of MSB can be performed under mild reaction conditions (t = 1 h, T = 70 ºC), and the solvents used can be recovered by distillation. BTCA is commercially available at moderate cost and can alternatively be obtained employing microbial succinic acid, metal-free catalysis, and modest use of petrochemical feedstocks. Furthermore, MSB can be reused, which could contribute to increasing the economic feasibility of water and wastewater treatment processes.


Assuntos
Saccharum , Poluentes Químicos da Água , Celulose/química , Cádmio/análise , Chumbo , Poluentes Químicos da Água/análise , Ácido Succínico , Cinética , Concentração de Íons de Hidrogênio , Adsorção , Água , Íons , Solventes
6.
Planta Med ; 88(13): 1163-1174, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34839466

RESUMO

Two pimaranes ent-pimara-8(14),15-dien-19-oic acid (1: ) and ent-8(14),15-pimaradien-3ß-ol (2: ), isolated from Aldama arenaria, and six semi-synthetic derivatives methyl ester of the ent-pimara-8(14),15-dien-19-oic acid (3: ), ent-pimara-8(14),15-dien-19-ol (4: ), acetate of ent-pimara-8(14),15-dien-19-ol (5: ), ent-pimara-8(14),15-dien-19-ol succinic acid (6: ), acetate of ent-8(14),15-pimaradien-3ß-ol (7: ), ent-8(14),15-pimaradien-3ß-ol succinic acid (8: ) were evaluated in vitro for their cytotoxic activities to childhood leukemia cell lines and leishmanicidal activity against the parasite Leishmania amazonensis. Among these compounds, 1: to 6: presented moderate cytotoxic activity, with compound 4: being the most active (GI50 of 2.6 µM for the HL60 line) and the derivatives 7: and 8: being inactive. Against the parasite Leishmania amazonensis, the most promising derivative was the acetate of ent-pimara-8(14),15-dien-19-ol (5: ), with EC50 of 20.1 µM, selectivity index of 14.5, and significant reduction in the parasite load. Pimarane analogues 1: , ent-pimara-8(14),15-dien-19-oic acid, and 2: , ent-8(14),15-pimaradien-3ß-ol, presented different activities, corroborating the application of such molecules as prototypes for the design of other derivatives that have greater cytotoxic or leishmanicidal potential.


Assuntos
Abietanos , Asteraceae , Ácido Succínico , Ésteres
7.
Food Chem ; 375: 131657, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34848086

RESUMO

Normal corn starch (∼26% amylose content) was subjected to different degrees of extrusion-based pregelatinization (55, 75, and 95%) to improve the efficiency of octenyl succinic anhydride (OSA) esterification. The partial disruption of the native semi-crystalline structure was verified with X-ray diffraction and Fourier transform infrared analysis. It was found that partial gelatinization (pregelatinization) reduced the relative crystallinity, which is an effect that was magnified by OSA esterification. Polarized and scanning electron microscopies revealed gradual destruction of the starch granules, yielding a fraction of insoluble remnants for high gelatinization degrees. The emulsification index showed a marked increase of about 18% by single extrusion treatment. However, fully stable emulsions (emulsification index = 1.0) were obtained by dual extrusion-esterification treatment. The hardness of hydrogels was reduced by pregelatinization. Principal component analysis revealed that most starch characteristics were mutually interdependent and that the impact of gelatinization degree was independent of the impact of OSA esterification.


Assuntos
Amido , Zea mays , Amilose , Emulsões , Ácido Succínico
8.
Anaesthesiol Intensive Ther ; 54(5): 357-364, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36734445

RESUMO

INTRODUCTION: Sepsis is a syndrome of physiological, pathological, and biochemical disorders with several processes co-occurring; reactive oxygen species (ROS) production and apoptosis are 2 of them. Succinate is a Krebs cycle intermediate that is oxydized in complex II of the mitochondria. This study aims to investigate the influence of succinate infusion on these processes. MATERIAL AND METHODS: Sepsis was induced with caecal ligation and puncture in 200 gr Sprague Dawley rats. Four groups were formed with 10 animals (1 - control, 2 - succinate, 3 - sepsis, and 4 - sepsis + succinate). 5 mmol kg-1 of intraperitoneal succinate were administered twice in groups 2 and 4. ROS and caspase-3 levels were measured. RESULTS: Overall, ROS levels (P = 0.017), but not caspase-3 levels (P = 0.89) differed significantly between the groups. The succinate administration reduced serum ROS levels (group 4 vs. 3) in a statistically significant way [0.0623 units (95% CI: 0.0547-0.0699) vs. 0.0835 (0.06-0.106), P = 0.017)], but it did not reduce serum caspase-3 levels (P = 0.39). There was no correlation between serum ROS levels and serum caspase-3 levels. CONCLUSIONS: In this model, ROS levels were reduced with succinate infusion, but caspase-3 levels were not. In addition, ROS levels and apoptosis levels are not correlated, which suggests that those processes occur at different times.


Assuntos
Sepse , Ácido Succínico , Animais , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio , Succinatos , Ácido Succínico/farmacologia
9.
Environ Sci Pollut Res Int ; 29(18): 26425-26448, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34859352

RESUMO

A new one-pot synthesis method optimized by a 23 experimental design was developed to prepare a biosorbent, sugarcane bagasse cellulose succinate pyromellitate (SBSPy), for the removal of Cu(II) and Zn(II) from single-component aqueous solutions, in batch and continuous modes. The bi-functionalization of the biosorbent with ligands of different chemical structures increased its selectivity, improving its performance for removing pollutants from contaminated water. The succinate moiety favored Cu(II) adsorption, while the pyromellitate moiety favored Zn(II) adsorption. Sugarcane bagasse (SB) and SBSPy were characterized using several techniques. Analysis by 13C Multi-CP SS NMR and FTIR revealed the best order of addition of each anhydride that maximized the chemical modification of SB. The maximum adsorption capacities of SBSPy for Cu(II) and Zn(II), in batch mode, were 1.19 and 0.95 mmol g-1, respectively. Homogeneous surface diffusion, intraparticle diffusion, and Boyd models were used to determine the steps involved in the adsorption process. Isothermal titration calorimetry was used to assess changes in enthalpy of adsorption as a function of SBSPy surface coverage. Fixed-bed column adsorption of Cu(II) and Zn(II) was performed in three cycles, showing that SBSPy has potential to be used in water treatment. Breakthrough curves were well fitted by the Thomas and Bohart-Adams models.


Assuntos
Saccharum , Poluentes Químicos da Água , Purificação da Água , Adsorção , Celulose/química , Concentração de Íons de Hidrogênio , Íons , Cinética , Saccharum/química , Ácido Succínico , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Zinco/análise
10.
Microbiology (Reading) ; 167(3)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33620307

RESUMO

Rhodobacter sphaeroides can use C4-dicarboxylic acids to grow heterotrophically or photoheterotropically, and it was previously demonstrated in Rhodobacter capsulatus that the DctPQM transporter system is essential to support growth using these organic acids under heterotrophic but not under photoheterotrophic conditions. In this work we show that in R. sphaeroides this transporter system is essential for photoheterotrophic and heterotrophic growth, when C4-dicarboxylic acids are used as a carbon source. We also found that over-expression of dctPQM is detrimental for photoheterotrophic growth in the presence of succinic acid in the culture medium. In agreement with this, we observed a reduction of the dctPQM promoter activity in cells growing under these conditions, indicating that the amount of DctPQM needs to be reduced under photoheterotrophic growth. It has been reported that the two-component system DctS and DctR activates the expression of dctPQM. Our results demonstrate that in the absence of DctR, dctPQM is still expressed albeit at a low level. In this work, we have found that the periplasmic component of the transporter system, DctP, has a role in both transport and in signalling the DctS/DctR two-component system.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Periplasma/metabolismo , Rhodobacter sphaeroides/metabolismo , Proteínas de Bactérias/genética , Transporte Biológico , Ácidos Dicarboxílicos/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos da radiação , Processos Heterotróficos , Luz , Proteínas de Membrana Transportadoras/genética , Periplasma/genética , Processos Fototróficos , Regiões Promotoras Genéticas , Rhodobacter sphaeroides/genética , Rhodobacter sphaeroides/crescimento & desenvolvimento , Rhodobacter sphaeroides/efeitos da radiação , Ácido Succínico/metabolismo
11.
Int J Mol Sci ; 21(18)2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32962179

RESUMO

In many cell types, epigenetic changes are partially regulated by the availability of metabolites involved in the activity of chromatin-modifying enzymes. Even so, the association between metabolism and the typical epigenetic reprogramming that occurs during preimplantation embryo development remains poorly understood. In this work, we explore the link between energy metabolism, more specifically the tricarboxylic acid cycle (TCA), and epigenetic regulation in bovine preimplantation embryos. Using a morphokinetics model of embryonic development (fast- and slow-developing embryos), we show that DNA methylation (5mC) and hydroxymethylation (5hmC) are dynamically regulated and altered by the speed of the first cleavages. More specifically, slow-developing embryos fail to perform the typical reprogramming that is necessary to ensure the generation of blastocysts with higher ability to establish specific cell lineages. Transcriptome analysis revealed that such differences were mainly associated with enzymes involved in the TCA cycle rather than specific writers/erasers of DNA methylation marks. This relationship was later confirmed by disturbing the embryonic metabolism through changes in α-ketoglutarate or succinate availability in culture media. This was sufficient to interfere with the DNA methylation dynamics despite the fact that blastocyst rates and total cell number were not quite affected. These results provide the first evidence of a relationship between epigenetic reprogramming and energy metabolism in bovine embryos. Likewise, levels of metabolites in culture media may be crucial for precise epigenetic reprogramming, with possible further consequences in the molecular control and differentiation of cells.


Assuntos
Blastocisto/enzimologia , Blastocisto/metabolismo , Ciclo do Ácido Cítrico , Metilação de DNA , Animais , Blastocisto/citologia , Bovinos , Meios de Cultura/metabolismo , Desenvolvimento Embrionário/genética , Metabolismo Energético , Epigênese Genética , Feminino , Perfilação da Expressão Gênica , Ontologia Genética , Ácidos Cetoglutáricos/metabolismo , Gravidez , Ácido Succínico/metabolismo
12.
Cell Biochem Biophys ; 78(1): 111-119, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32062829

RESUMO

There are different varieties of mushrooms not yet studied spread all over the planet. The objective of this study was to evaluate biochemical properties and effects on mitochondrial respiration of eight Basidiomycete mushrooms: Flaviporus venustus EF30, Hydnopolyporus fimbriatus EF41 and EF44, Inonotus splitgerberi EF46, Oudemansiella canarii EF72, Perenniporia sp. EF79, Phellinus linteus EF81, and Pleurotus albidus EF84. Total phenols, ABTS, TEAC, FRAP, and ORAC were measured in order to determine the antioxidant capacity. Antimicrobial potential was studied by disc-diffusion and microdilution method. Cytotoxicity was determined in murine peritoneal macrophages. The bioenergetic aspects were evaluated by the uncoupling of the oxidative phosphorylation in mitochondrias. The H. fimbriatus mushroom was the one that presented the most significant results for the antioxidant assays. Three mushrooms presented antimicrobial activity, indicating a potential for formulation of drugs. The results suggest that I. spligerberi has an uncoupling activity, even at the lowest concentration tested, dissipating the mitochondrial electrochemical gradient. On the other hand, P. albidus has effect only on succinate-oxidase activity without influencing mitochondrial respiratory efficiency. Therefore, both interfere negatively in mitochondrial respiration. In relation with the cytotoxicity in peritoneal macrophages, O. canarii and F. venustus were cytotoxic in this type of cells.


Assuntos
Basidiomycota/química , Mitocôndrias/efeitos dos fármacos , Fenóis/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/metabolismo , Basidiomycota/metabolismo , Macrófagos Peritoneais/citologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Mitocôndrias/metabolismo , Oxirredução , Fosforilação Oxidativa/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Fenóis/isolamento & purificação , Fenóis/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Ácido Succínico/química
13.
Food Chem ; 304: 125434, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31491711

RESUMO

The effect of amylose content in the in vitro digestibility of non-modified and OSA-modified corn starch was studied. Corn starches with different amylose content (waxy, normal and Hylon VII) were treated with 3% OSA solution. In vitro digestibility tests showed that OSA treatment reduced the fraction of fastly digestible starch, an effect that was more pronounced for cooked starch. The amylose content was negatively linked to the decrease of in vitro digestion. HPSEC analysis was conducted to gain insights on the effect of OSA-treatment on in vitro digestibility. The results showed an increase of the molecular weight of starch chains. Besides, the molecular weight increase was similar for amylose and amylopectin fractions. This suggests that OSA could be acting as a cross-linking agent between starch chains, reducing the susceptibility to amylolysis. Overall, OSA treatment induced the formation of more complex starch chains, offering more resistance for amylolytic reactions.


Assuntos
Amido/metabolismo , Ácido Succínico/química , Zea mays/química , Amilopectina , Amilose , Hidrólise , Amido/química
14.
Exp Parasitol ; 208: 107792, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31707003

RESUMO

Nitazoxanide (NTZ) is a broad-spectrum drug used in intestinal infections, but still poorly explored in the treatment of parasitic tissular infections. This study aimed to evaluate the in vitro responses of the energetic metabolism of T. crassiceps cysticerci induced by NTZ. The organic acids of the tricarboxylic acid cycle, products derived from fatty acids oxidation and protein catabolism were analyzed. These acids were quantified after 24 h of in vitro exposure to different NTZ concentrations. A positive control group was performed with albendazole sulfoxide (ABZSO). The significant alterations in citrate, fumarate and malate concentrations showed the NTZ influence in the tricarboxylic acid (TCA) cycle. The non-detection of acetate confirmed that the main mode of action of NTZ is effective against T. crassiceps cysticerci. The statistical differences in fumarate, urea and beta-hydroxybutyrate concentrations showed the NTZ effect on protein catabolism and fatty acid oxidation. Therefore, the main energetic pathways such as the TCA cycle, protein catabolism and fatty acids oxidation were altered after in vitro NTZ exposure. In conclusion, NTZ induced a significant metabolic stress in the parasite indicating that it may be used as an alternative therapeutic choice for cysticercosis treatment. The use of metabolic approaches to establish comparisons between anti parasitic drugs mode of actions is proposed.


Assuntos
Antiparasitários/farmacologia , Taenia/efeitos dos fármacos , Tiazóis/farmacologia , Albendazol/análogos & derivados , Albendazol/farmacologia , Análise de Variância , Animais , Anti-Helmínticos/farmacologia , Citratos/metabolismo , Ciclo do Ácido Cítrico/efeitos dos fármacos , Meios de Cultura/química , Cysticercus/efeitos dos fármacos , Cysticercus/metabolismo , Metabolismo Energético/efeitos dos fármacos , Fumaratos/metabolismo , Ácidos Cetoglutáricos/metabolismo , Malatos/metabolismo , Neurocisticercose/tratamento farmacológico , Nitrocompostos , Ácido Oxaloacético/metabolismo , Ácido Succínico/metabolismo , Taenia/metabolismo
15.
Biochem J ; 476(20): 2939-2952, 2019 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-31548269

RESUMO

ATP-dependent phosphoenolpyruvate carboxykinases (PEPCKs, EC 4.1.1.49) from C4 and CAM plants have been widely studied due to their crucial role in photosynthetic CO2 fixation. However, our knowledge on the structural, kinetic and regulatory properties of the enzymes from C3 species is still limited. In this work, we report the recombinant production and biochemical characterization of two PEPCKs identified in Arabidopsis thaliana: AthPEPCK1 and AthPEPCK2. We found that both enzymes exhibited high affinity for oxaloacetate and ATP, reinforcing their role as decarboxylases. We employed a high-throughput screening for putative allosteric regulators using differential scanning fluorometry and confirmed their effect on enzyme activity by performing enzyme kinetics. AthPEPCK1 and AthPEPCK2 are allosterically modulated by key intermediates of plant metabolism, namely succinate, fumarate, citrate and α-ketoglutarate. Interestingly, malate activated and glucose 6-phosphate inhibited AthPEPCK1 but had no effect on AthPEPCK2. Overall, our results demonstrate that the enzymes involved in the critical metabolic node constituted by phosphoenolpyruvate are targets of fine allosteric regulation.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Fosfoenolpiruvato Carboxiquinase (ATP)/química , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Trifosfato de Adenosina/metabolismo , Regulação Alostérica , Ácido Cítrico/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Fluorometria/métodos , Fumaratos/metabolismo , Cinética , Malatos/metabolismo , Manganês/metabolismo , Ácido Oxaloacético/metabolismo , Fotossíntese , Ligação Proteica , Proteínas Recombinantes/metabolismo , Ácido Succínico/metabolismo , Temperatura de Transição
16.
Blood Transfus ; 17(5): 347-356, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30747701

RESUMO

BACKGROUND: Understanding the molecular mechanisms in perturbation of the metabolome following ischaemia and reperfusion is critical in developing novel therapeutic strategies to prevent the sequelae of post-injury shock. While the metabolic substrates fueling these alterations have been defined, the relative contribution of specific organs to the systemic metabolic reprogramming secondary to ischaemic or haemorrhagic hypoxia remains unclear. MATERIALS AND METHODS: A porcine model of selected organ ischaemia was employed to investigate the relative contribution of liver, kidney, spleen and small bowel ischaemia/reperfusion to the plasma metabolic phenotype, as gleaned through ultra-high performance liquid chromatography-mass spectrometry-based metabolomics. RESULTS: Liver ischaemia/reperfusion promotes glycaemia, with increases in circulating carboxylic acid anions and purine oxidation metabolites, suggesting that this organ is the dominant contributor to the accumulation of these metabolites in response to ischaemic hypoxia. Succinate, in particular, accumulates selectively in response to the hepatic ischemia, with levels 6.5 times spleen, 8.2 times small bowel, and 6 times renal levels. Similar trends, but lower fold-change increase in comparison to baseline values, were observed upon ischaemia/reperfusion of kidney, spleen and small bowel. DISCUSSION: These observations suggest that the liver may play a critical role in mediating the accumulation of the same metabolites in response to haemorrhagic hypoxia, especially with respect to succinate, a metabolite that has been increasingly implicated in the coagulopathy and pro-inflammatory sequelae of ischaemic and haemorrhagic shock.


Assuntos
Fígado/metabolismo , Metaboloma , Traumatismo por Reperfusão/metabolismo , Animais , Fígado/patologia , Masculino , Oxirredução , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/patologia , Ácido Succínico/sangue , Ácido Succínico/metabolismo , Suínos
17.
Oxid Med Cell Longev ; 2018: 1928945, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30524651

RESUMO

In sepsis, reactive oxygen species (ROS) production is increased. This process takes place mainly within the electron transport chain. ROS production is part of the pathophysiology of multiple organ failure in sepsis. Succinate yields Dihydroflavine-Adenine Dinucleotide (FADH2), which enters the chain through complex II, avoiding complex I, through which electrons are lost. The aim of this work is to determine if parenteral succinate reduces systemic ROS production and improves kidney function. Rats with cecal ligation and puncture were used as model of sepsis, and 4 groups were made: Control group; Succinate group, which only received parenteral succinate; Sepsis group; and Sepsis which received parenteral succinate. Systemic ROS are measured 24 hours after the procedure. Rats subjected to cecal puncture treated with succinate had less systemic ROS than Septic untreated rats (p = 0.007), while there were no differences in creatinine levels (p = 0.07). There was no correlation between creatinine and systemic ROS levels (p = 0.3). We concluded that parenteral succinate reduces ROS levels, but it does not reduce creatinine levels. Since there is no correlation between both levels, the processes would not be related.


Assuntos
Creatinina/metabolismo , Nutrição Parenteral , Espécies Reativas de Oxigênio/metabolismo , Insuficiência Renal/prevenção & controle , Sepse/complicações , Ácido Succínico/administração & dosagem , Animais , Ceco/cirurgia , Ligadura , Masculino , Oxirredução , Ratos , Ratos Sprague-Dawley , Insuficiência Renal/etiologia , Insuficiência Renal/metabolismo , Ácido Succínico/metabolismo
18.
Appl Environ Microbiol ; 84(19)2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30030227

RESUMO

Manipulation of global regulators is one of the strategies used for the construction of bacterial strains suitable for the synthesis of bioproducts. However, the pleiotropic effects of these regulators can vary under different conditions and are often strain dependent. This study analyzed the effects of ArcA, CreC, Cra, and Rob using single deletion mutants of the well-characterized and completely sequenced Escherichia coli strain BW25113. Comparison of the effects of each regulator on the synthesis of major extracellular metabolites, tolerance to several compounds, and synthesis of native and nonnative bioproducts under different growth conditions allowed the discrimination of the particular phenotypes that can be attributed to the individual mutants and singled out Cra and ArcA as the regulators with the most important effects on bacterial metabolism. These data were used to identify the most suitable backgrounds for the synthesis of the reduced bioproducts succinate and 1,3-propanediol (1,3-PDO). The Δcra mutant was further modified to enhance succinate synthesis by the addition of enzymes that increase NADH and CO2 availability, achieving an 80% increase compared to the parental strain. Production of 1,3-PDO in the ΔarcA mutant was optimized by overexpression of PhaP, which increased more than twice the amount of the diol compared to the wild type in a semidefined medium using glycerol, resulting in 24 g · liter-1 of 1,3-PDO after 48 h, with a volumetric productivity of 0.5 g · liter-1 h-1IMPORTANCE Although the effects of many global regulators, especially ArcA and Cra, have been studied in Escherichia coli, the metabolic changes caused by the absence of global regulators have been observed to differ between strains. This scenario complicates the identification of the individual effects of the regulators, which is essential for the design of metabolic engineering strategies. The genome of Escherichia coli BW25113 has been completely sequenced and does not contain additional mutations that could mask or interfere with the effects of the global regulator mutations. The uniform genetic background of the Keio collection mutants enabled the characterization of the physiological consequences of altered carbon and redox fluxes caused by each global regulator deletion, eliminating possible strain-dependent results. As a proof of concept, Δcra and ΔarcA mutants were subjected to further manipulations to obtain large amounts of succinate and 1,3-PDO, demonstrating that the metabolic backgrounds of the mutants were suitable for the synthesis of bioproducts.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Deleção de Genes , Regulação Bacteriana da Expressão Gênica , Proteínas Repressoras/metabolismo , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Escherichia coli/genética , Glicerol/metabolismo , Engenharia Metabólica , Propilenoglicóis/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteínas Repressoras/genética , Ácido Succínico/metabolismo
19.
J Nanosci Nanotechnol ; 18(6): 3832-3843, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442716

RESUMO

In this study, we report the synthesis and characterization of a new rhodium(II) succinate complex (Rh2(suc)4) and its immobilization on lauric acid bilayer-coated maghemite nanoparticles (MGH-2L/Rh2(suc)4) and subsequent adsorption with bovine serum albumin (MGH-2L/Rh2(suc)4/BSA). Rh2(suc)4 has been characterized by elemental analysis, potentiometric titration, TGA, MS, FTIR and UV-Vis analysis. The maghemite phase was confirmed by XRD, and a diameter of 10 nm was obtained by Sherrer equation. The VSM experiment showed superparamagnetic properties. TEM showed nanoparticles with a spherical shape and a mean diameter of 8.5±0.4 and 9.1 ± 0.4 nm for MGH-2L/Rh2(suc)4 and MGH-2L/Rh2(suc)4/BSA, respectively. FTIR and TGA confirmed the immobilization of Rh2(suc)4 and bovine serum albumin adsorption on superparamagnetic iron oxide. Hydrodynamic size (DH) and zeta potential (ζ) measurements were made in aqueous, NaCl and DMEM media. DH for dispersions was lower in aqueous medium, but increased in saline and DMEM media. In aqueous and saline media, ζ was not altered for MGH-2L and MGH-2L/Rh2(suc)4, but was significantly lower for MGH-2L/Rh2(suc)4/BSA. Therefore, MGH-2L/Rh2(suc)4/BSA was the most stable dispersion, meaning that BSA coating prevents aggregation more than lauric acid bilayer coating. MGH-2L/Rh2(suc)4 and MGH-2L/Rh2(suc)4/BSA dispersions induced cytotoxicity in breast carcinoma (MCF-7) and fibroblast cells in culture, and this effect was higher than that exerted by free Rh2(suc)4 and more specific to breast carcinoma cells than to fibroblasts. Therefore, we suggest that these dispersions have an important potential for future clinical applications and, thus, they should be considered a platform to enhance Rh2(suc)4 cytotoxicity, specifically in breast carcinoma.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Ácidos Láuricos , Nanopartículas Metálicas , Ródio , Ácido Succínico , Compostos Férricos , Humanos , Nanopartículas , Soroalbumina Bovina , Succinatos , Células Tumorais Cultivadas
20.
Faraday Discuss ; 202: 213-225, 2017 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-28671699

RESUMO

This paper proposes a framework with six dimensions that can be useful for evaluating the potential and the current stage of a bio-based platform chemical. The framework considers the technological and strategic challenges to be fulfilled by a company that intends to lead a platform based on a bio-based chemical. A platform chemical should be an intermediate molecule, with a structure able to generate a number of derivatives, that is produced at a competitive cost, capable of allowing exploitation of the scale and scope economies, and inserted within a complete innovation ecosystem that is able to create value with governance mechanisms that are capable of allowing coordination of the innovation process and facilitation of the value capture by the focal company leading the platform, in our case the producer of the platform molecule. Based on these six dimensions, three potential platform chemicals - succinic acid, butanol and farnesene - are compared and discussed. It is possible to identify important differences concerning the technological dimensions and the strategic dimensions as well. Two of the molecules - farnesene and succinic acid - adhere to most of the conditions required to structure a platform chemical. However, the innovation ecosystem is not complete and the governance mechanisms are still under development, so it is not clear if they will be capable of allowing a favorable position for value capture by the platform leader. Butanol structuring for a platform does not seem promising. The potential of the molecule is apparently not high and the strategic initiatives are in general not focused on innovation ecosystem structuring.


Assuntos
Alcenos/isolamento & purificação , Biotecnologia , Butanóis/isolamento & purificação , Ácido Succínico/isolamento & purificação , Alcenos/química , Butanóis/química , Ácido Succínico/química
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