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1.
J Environ Sci (China) ; 85: 208-219, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471028

RESUMO

Methyl tert-butyl ether (MTBE), as a widely used gasoline additive, is suspected of being environmentally toxic. MTBE accumulates mainly in adipose tissue, but its effect on obesity or obesity-related metabolic disorders has not been well understood yet. Therefore, we examined the effect of MTBE on the adipose function and the related metabolic processes with both 3T3-L1 cell line and C57BL/6J mice model. We found that exposure to MTBE at the environmental relevant concentration (100 µmol/L) could significantly induce differentiation of preadipocyte and disturb insulin-stimulated glucose uptake of mature adipocyte. The in vivo observation in male mice showed a positive correlation of visceral white adipose tissue (vWAT) expansion and cell size increase with MTBE treatment in 14 weeks. Glucose tolerance and insulin sensitivity tests demonstrated that MTBE at 1000 µg/(kg·day) disturbed the systemic glucose metabolism in a gender-specific manner, which might be partly attributed to the alterations of gut microbiota community at genus level with respect to Akkermansia, Clostridium XlVb, and Megamonas. In summary, our study characterized the effect of MTBE on adipose tissue function and glucose homeostasis in vitro and in vivo, and revealed that systemic disorders of the glucose metabolism might be modulated by the related gut microbiota.


Assuntos
Poluentes Atmosféricos/toxicidade , Metabolismo dos Carboidratos/efeitos dos fármacos , Éteres Metílicos/toxicidade , Animais , Gasolina , Glucose/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Testes de Toxicidade
2.
Chem Commun (Camb) ; 55(66): 9869-9872, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31364617

RESUMO

In this work, we designed and synthesized an aggregation-induced emission (AIE)-active tetraphenylethene-decorated pseudo-trisialic acid (TPE3S) and validated its high affinity for Siglecs using microscale thermophoresis techniques. TPE3S was a unique binding-on fluorescent trivalent sialocluster which was successfully utilized for the visualization of Siglecs expressed on the surface of mammalian cells.


Assuntos
Metabolismo dos Carboidratos , Lectinas/metabolismo , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/metabolismo , Animais , Membrana Celular/metabolismo , Corantes Fluorescentes/química , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Células PC12 , Ligação Proteica , Ratos
3.
Plant Foods Hum Nutr ; 74(3): 430-435, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31302831

RESUMO

The beneficial health effects of apple consumption are well known, however, little is known about the potential of its phenolic fractions to inhibit α-glucosidases and thereafter to treat diseases related to the carbohydrate metabolism, such as postprandial hyperglycemia and diabetes. In the present study, the α-glucosidase inhibition and antioxidant activity of different phenolic fractions of apple were evaluated using the 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging activity. Moreover, the phenolic fractions were chemically characterized by LC-MS in order to identify the compounds responsible for the biological properties. The purified extract (not fractionated) had the highest α-glucosidase and hydroxyl radical inhibitions. The purified extract and fractions III and IV were more active against the enzyme activity than the positive control acarbose, the drug used by diabetic patients to treat postprandial hyperglycaemia. Our results show that apple phenolic extracts strongly inhibit α-glucosidase acitivity, validating their potential to be used in the management of type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores de Glicosídeo Hidrolases/farmacologia , Hiperglicemia/tratamento farmacológico , Malus/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Metabolismo dos Carboidratos , Fenóis/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/isolamento & purificação , alfa-Glucosidases/metabolismo
4.
Bioresour Technol ; 289: 121746, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31323709

RESUMO

This study focused on the effect of hydrothermal treatment (HTT) on biochemical methane potential (BMP) of Chlorella sp. The BMP was in the range of 119.16-485.90 mLCH4/gVS, and increased by 80.31%-210.16% after HTT, while reduced 23.94% at hydrothermal treatment severity (HTS) 5.21. The cell wall was more greatly disrupted with increasing HTS, accompanied with the increase of volatile fatty acids (VFAs) and fermentation inhibitors (5-HMF and more complex chemical compositions) recoveries. The reducing sugar yields were 0.94-3.65% and obtained its maximum at a retention time of 30 min. Illumina MiSeq sequencing clarified that, the phylum Chloroflexi with functions of hydrolysis and acidogenesis, decreased with increasing HTS. The family Methanosaetaceae belonging to acetoclastic methanogens, had an unexpected decrease at HTS 5.21. As the response, VFAs concentration was less than 1 g/L after biochemical metabolism, while high concentrations of VFAs and inhibitors at HTS 5.21 led to the poor performance.


Assuntos
Chlorella/metabolismo , Metano/metabolismo , Fenômenos Bioquímicos , Metabolismo dos Carboidratos , Carboidratos , Ácidos Graxos Voláteis/biossíntese , Hidrólise
5.
J Anim Sci ; 97(7): 2837-2849, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31267132

RESUMO

Ketosis is a major metabolic disorder of high-yielding dairy cows during the transition period. Although metabolic adaptations of the adipose tissue are critical for a successful transition, beyond lipolysis, alterations within adipose tissue during ketosis are not well known. The objective of this study was to investigate the adipose tissue proteome of healthy or ketotic postpartum cows to gain insights into biological adaptations that may contribute to disease outcomes. Adipose tissue biopsy was collected on 5 healthy and 5 ketotic cows at 17 (±4) d postpartum and ketosis was defined according to the clinical symptoms and serum ß-hydroxybutyrate concentration. Morphology micrographs stained by hematoxylin-eosin showed that adipocytes were smaller in ketotic cows than in healthy cows. The isobaric tag for relative and absolute quantification was applied to quantitatively identify differentially expressed proteins (DEP) in the adipose tissue. We identified a total of 924 proteins, 81 of which were differentially expressed between ketotic and healthy cows (P < 0.05 and fold changes >1.5 or <0.67). These DEP included enzymes and proteins associated with various carbohydrate, lipid, and amino acid metabolism processes. The top pathways differing between ketosis and control cows were glycolysis/gluconeogenesis, glucagon signaling pathway, cysteine and methionine metabolism, biosynthesis of amino acids, and the cGMP-PKG signaling pathway. The identified DEP were further validated by western blot and co-immunoprecipitation assay. Key enzymes associated with carbohydrate metabolism such as pyruvate kinase 2, pyruvate dehydrogenase E1 component subunit α), lactate dehydrogenase A , phosphoglucomutase 1, and 6-phosphofructokinase 1 were upregulated in ketotic cows. The expression and phosphorylation state of critical regulators of lipolysis such as perilipin-1 and hormone-sensitive lipase were also upregulated in ketotic cows. Furthermore, key proteins involved in maintaining innate immune response such as lipopolysaccharide binding protein and regakine-1 were downregulated in ketotic cows. Overall, data indicate that ketotic cows during the transition period have altered carbohydrate, lipid metabolism, and impaired immune function in the adipose tissue. This proteomics analysis in adipose tissue of ketotic cows identified several pathways and proteins that are components of the adaptation to ketosis.


Assuntos
Adaptação Fisiológica , Doenças dos Bovinos/metabolismo , Cetose/veterinária , Leite/metabolismo , Proteoma , Proteômica , Ácido 3-Hidroxibutírico/sangue , Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Animais , Biomarcadores/análise , Metabolismo dos Carboidratos , Bovinos , Feminino , Regulação da Expressão Gênica , Imunidade Inata , Cetose/metabolismo , Lactação , Metabolismo dos Lipídeos , Redes e Vias Metabólicas , Fosforilação , Período Pós-Parto , Transdução de Sinais
6.
Ying Yong Sheng Tai Xue Bao ; 30(6): 1854-1860, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31257756

RESUMO

To clarify the effects and underlying mechanism of ABA on sugar accumulation in apple fruits, 13C trace technique was used to examined the effects of different ABA levels (0, 50, 100 and 150 mg·L-1) and fluoridone (ABA biosynthesis inhibitor) on translocation of photosynthate to fruit during late stage of fruit rapid-swelling in five-year-old 'Yanfu3'/M26/Malus hupehensis Rehd. The results showed that the activities of related enzyme in sugar metabolism, the relative expression of sucrose transporter gene MdSUT1, MdSUT2.2 and sorbitol transporter gene MdSOT3 tended to increase first and then decrease with increasing ABA concentration, with a peak in 100 mg·L-1ABA treatment. Fluridone treatment significantly inhibited the enzymes activities of sugar metabolism and the relative expression of sugar transporters. The treatment of 100 mg·L-1ABA significantly reduced leaf 13C content, increased fruit 13C content and increased the transport rate of photosynthate from leaves to fruits compared with other treatments. Our results indicated that exogenous ABA enhanced sink strength of fruit and promoted the transportation of more photosynthate to fruits, which increased the soluble sugar content in fruits.


Assuntos
Ácido Abscísico/metabolismo , Frutas/fisiologia , Malus , Metabolismo dos Carboidratos , Carboidratos , Frutas/química , Folhas de Planta
7.
Plant Sci ; 286: 108-117, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300136

RESUMO

It has been reported that drought stress (DS) reduces cotton yield by negatively affecting reproductive activities. Some studies have investigated the effects of DS on pollen physiology and biochemistry, but studies exploring the impact of drought on pistil biochemistry and its relationship with pollen tube growth rates in vivo are scarce. In order to investigate these objectives, a greenhouse study was conducted with a drought sensitive cotton cultivar, Yuzaomian 9110. Two water treatments were imposed at flowering stage, 1. control, where plants were irrigated with optimum quantity of water and 2. DS treatment, where plants were irrigated with 50% of the optimum quantity of water. Results indicated that stored starch content at the early stage of pollen tube growth (12:00 h) was 31.6% lower in drought-stressed pistils than control pistils, and it was highly correlated with pollen tube growth rate. The decline in starch accumulation of drought-stressed pistils could be attributed to the impeded transport of photosynthetic carbon assimilates. Moreover, decreased ADP-glucose pyrophosphorylase and soluble starch synthase activities also resulted in curtailing starch accumulation in drought-stressed pistils. Furthermore, pistil sucrose concentration was significantly higher in droughted plants relative to control plants at 12:00 and 18:00 h (during the rapid growth period), which was due to lower activities of sucrose synthase and acid invertase, and the down-regulated expressions of sucrose synthase genes, GhSusA, GhSusB and GhSusD, and acid invertase genes, GhINV1 and GhINV2, in drought-stressed pistils, limiting as a result the hydrolysis of sucrose into hexose. Drought-stressed pistils sampled at 18:00 h had lower α-amylase activity compared to control pistils, resulting in decreased starch decomposition, which, in conjunction with the decreased hydrolysis of sucrose, led to lower glucose and fructose contents in drought-stressed pistils at 18:00 h. Finally, lower pyruvate level in drought-stressed pistils could not produce enough acetyl-CoA in the tricarboxylic acid cycle to yield sufficient energy (ATP) for pollen tube growth. We conclude that DS disrupts the carbohydrate balance of pistil, reducing as a consequence carbon and energy supply for pollen tube elongation in the style, which will ultimately result in reproductive failure.


Assuntos
Metabolismo dos Carboidratos , Secas , Gossypium/genética , Gossypium/metabolismo , Flores/metabolismo , Tubo Polínico/crescimento & desenvolvimento , Tubo Polínico/metabolismo
8.
J Int Soc Sports Nutr ; 16(1): 28, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299980

RESUMO

A recently published meta-analysis in this journal analyzed findings from studies comparing substrate use during exercise at the same relative intensity (i.e., % V̇O2max) in normoxic and hypoxic conditions. The primary conclusion was that hypoxia had no consistent effects on the contribution of carbohydrate oxidation to total energy expenditure. However, findings from studies comparing exercise at the same absolute intensity in normoxic as hypoxic conditions were not considered in the meta-analysis. Assessment of substrate oxidation using matched absolute intensity leads to different conclusions regarding hypoxic effects on fuel use during exercise, and that experimental model, (i.e., comparing responses to exercise at matched absolute intensity) has more practical application for developing nutritional recommendations for high-altitude sojourners. This commentary will discuss those differences.


Assuntos
Metabolismo Energético , Exercício , Hipóxia , Altitude , Metabolismo dos Carboidratos , Humanos , Metanálise como Assunto , Oxirredução , Consumo de Oxigênio
9.
Orv Hetil ; 160(25): 973-979, 2019 Jun.
Artigo em Húngaro | MEDLINE | ID: mdl-31203640

RESUMO

Progranulin is a recently recognized multifunctional glycopeptide shown to be related to obesity and diabetes mellitus. Progranulin is an endogenous antagonist of tumor necrosis factor-α by competitively binding to its receptor, therefore, it exerts anti-inflammatory activity. Paradoxically, previous studies have shown that serum levels of progranulin were elevated in patients with diabetes and associated to its complications including micro- and macroangiopathies, macroalbuminuria or reduced renal function. Moreover, hyperprogranulinemia may be involved in the pathogenesis of obesity-associated insulin resistance. The review summarizes the currently available data on progranulin as a novel marker of the carbohydrate metabolism and inflammation. Orv Hetil. 2019; 160(25): 973-979.


Assuntos
Metabolismo dos Carboidratos/fisiologia , Progranulinas/sangue , Biomarcadores/sangue , Humanos , Inflamação/sangue , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Prognóstico
10.
Plant Physiol Biochem ; 141: 164-171, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31170640

RESUMO

For a comprehensive understanding of gene expression, enzyme activity and sugar concentrations in response to short-term water deficit in apple (Greensleeves), sugar-modulated gene expression and enzyme activities were analyzed. Water stress resulted in the accumulation of sorbitol, glucose, fructose, galactose and starch, accompanied by a significant reduction in photosynthesis and sucrose concentration. In response to short-term water deficits, the activities of aldose-6-phosphate reductase (A6PR; EC 1.1.1.200), sorbitol dehydrogenase (SDH; EC 1.1.1.14), neutral invertase (NINV; EC 3.2.1.26), sucrose synthase (SUSY; EC 2.4.1.13), and fructokinase (FK; EC 2.7.1.4) were higher, whereas cell wall invertase (CWINV; EC 3.2.1.26) and hexokinase (HK; EC 2.7.1.1) activities were lower. In addition, sucrose phosphate synthase (SPS; EC 2.4.1.14) activity increased during the initial stages of dehydration and then decreased as the drought strengthened. Transcript levels of MdA6PR, MdSDH1/2, MdNINV1/2, MdSUSY3, MdFK1/2/4, MdSOT1/2, MdSUC1-3, MdTMT2/3, MdvGT1, MdpGlcT1-4 were upregulated, whereas transcript levels of MdCWINV1/2, MdHK1/2/3/5, and MdTMT1 were downregulated after 6 days of water stress. These findings suggest that the sorbitol metabolism pathway is induced and high levels of hexose derived from photosynthetic products are transported into vacuoles for adjustment to the water deficit. Our results provide insights into the relationships between sugar levels and sugar-modulated gene and enzyme activity in response to the imposition of short-term water stress.


Assuntos
Metabolismo dos Carboidratos/genética , Secas , Regulação da Expressão Gênica de Plantas , Malus/fisiologia , Folhas de Planta/fisiologia , Parede Celular/metabolismo , Frutas/metabolismo , Glucosiltransferases/metabolismo , Malus/genética , Fotossíntese , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/fisiologia , Sorbitol/metabolismo , Estresse Fisiológico , Sacarose/metabolismo , beta-Frutofuranosidase/metabolismo
11.
Plant Physiol Biochem ; 141: 172-182, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31174034

RESUMO

Chickpea (Cicer arietinum L.), a cool season crop is severely affected by heat stress, predicted to increase due to warming climates. Research for identifying heat tolerance markers for potential chickpea genotype selection is imperative. The study assessed the response of four chickpea genotypes to a natural temperature gradient in the field using chlorophyll fluorescence, non-structural carbohydrate, chlorophyll concentrations, gas exchange and grain yield. Field experiments were carried out in two winter seasons at three locations with known differences in temperature in NE South Africa. Results showed two genotypes were tolerant to heat stress with an Fv/Fm of 0.83-0.85 at the warmer site, while the two sensitive genotypes showed lower Fv/Fm of 0.78-0.80. Both dark-adapted Fv/Fm and Fq'/Fm' (where Fq' = Fm' -F) measured at comparable high light levels correlated positively with grain yield. The two tolerant genotypes also showed higher photosynthetic rates, starch, sucrose and grain yield than the sensitive genotypes at the warmer site. However, these parameters were consistently higher at the cooler sites than at the warmer. These results were further validated by a climate chamber experiment, where higher Fv/Fm decline in the sensitive compared to tolerant genotypes was observed when they were exposed to short-term heat treatments of 30/25 °C and 35/30 °C. Tolerant genotypes had higher Fv/Fm (0.78-0.81) and grain yield plant-1(1.12-2.37g) compared to sensitive genotypes (0.74-0.75) and (0.32-0.89g plant-1) respectively in the 35/30 °C. It is concluded that chlorophyll fluorescence and leaf carbohydrates are suitable tools for selection of heat tolerant chickpea genotypes under field conditions, while the coolest site showed favourable conditions for chickpea production.


Assuntos
Carboidratos/química , Clorofila/química , Cicer/genética , Produção Agrícola/métodos , Fluorescência , Genótipo , Aclimatação , África ao Sul do Saara , Metabolismo dos Carboidratos , Cicer/química , Genes de Plantas , Temperatura Alta , Fenótipo , Fotossíntese , Complexo de Proteína do Fotossistema II/química , Folhas de Planta/química
12.
Carbohydr Polym ; 219: 12-20, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151508

RESUMO

Including additives in the culture media during bacterial cellulose (BC) biosynthesis is a traditional method to produce BC-based nanocomposites. This study examines a novel fermentation process, which is to co-culture Gluconacetobacter hansenii (G. hansenii) with Escherichia coli (E. coli) under static conditions, to produce BC pellicles with enhanced mechanical properties. The mannose-rich exopolysaccharides (EPS) synthesized by E. coli were incorporated into the BC network and affected the aggregation of co-crystallized microfibrils without significantly changing the crystal sizes of BC. When co-culturing G. hansenii ATCC 23769 with E. coli ATCC 700728, which produced a low concentration of EPS at 3.3 ± 0.7 mg/L, the BC pellicles exhibited a Young's modulus of 4,874 ± 1144 MPa and a stress at break of 80.7 ± 21.1 MPa, which are 81.9% and 79.3% higher than those of pure BC, respectively. The growth dynamics of the two co-cultured strains suggested that the production of BC and EPS were enhanced through co-culturing fermentation.


Assuntos
Celulose/química , Técnicas de Cocultura/métodos , Escherichia coli/metabolismo , Gluconacetobacter/metabolismo , Nanocompostos/química , Metabolismo dos Carboidratos , Cristalização , Fermentação , Fenômenos Mecânicos , Microfibrilas
13.
Food Chem ; 297: 125016, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253287

RESUMO

To gain a better understanding concerning factors underlying carotenoid metabolism in banana pulp we investigated the carotenoid profile, metabolome, proteome and relative expression levels of carotegenesis-associated genes of fruit pulp in the two banana varieties ON and GN, with ON being characterized of high carotenoid accumulation. Results showed that high carotenoid content in banana pulp was well correlated with the relative expression of carotenogenesis-associated genes and the abundance of the corresponding proteins. An elevated accumulation of sugar metabolism-related compounds and a decreased amino acid accumulation were also observed in ON. Additionally proteins involved in the glycolytic pathway were more highly abundant in ON suggesting that this supports the higher accumulation of carotenoid in this genotype. We suggest that up-regulated expression of carotenogenesis-associated genes alongside elevated carbohydrate accumulation contribute to high carotenoid content in banana pulp, implying that a multi-target approach is necessary in order to improve carotenoid content in banana.


Assuntos
Carotenoides/análise , Metaboloma , Metabolômica/métodos , Musa/metabolismo , Proteômica/métodos , Aminoácidos/análise , Aminoácidos/metabolismo , Metabolismo dos Carboidratos , Carotenoides/metabolismo , Cromatografia Líquida de Alta Pressão , Análise Discriminante , Frutas/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Glicólise , Proteínas de Plantas/genética , Proteoma/análise , Espectrometria de Massas em Tandem
14.
Nat Commun ; 10(1): 2756, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227702

RESUMO

Flight loss in birds is as characteristic of the class Aves as flight itself. Although morphological and physiological differences are recognized in flight-degenerate bird species, their contributions to recurrent flight degeneration events across modern birds and underlying genetic mechanisms remain unclear. Here, in an analysis of 295 million nucleotides from 48 bird genomes, we identify two convergent sites causing amino acid changes in ATGLSer321Gly and ACOT7Ala197Val in flight-degenerate birds, which to our knowledge have not previously been implicated in loss of flight. Functional assays suggest that Ser321Gly reduces lipid hydrolytic ability of ATGL, and Ala197Val enhances acyl-CoA hydrolytic activity of ACOT7. Modeling simulations suggest a switch of main energy sources from lipids to carbohydrates in flight-degenerate birds. Our results thus suggest that physiological convergence plays an important role in flight degeneration, and anatomical convergence often invoked may not.


Assuntos
Evolução Biológica , Aves/fisiologia , Metabolismo Energético/genética , Voo Animal/fisiologia , Genoma/genética , Animais , Metabolismo dos Carboidratos/fisiologia , Genômica/métodos , Lipase/genética , Lipase/metabolismo , Lipólise/fisiologia , Palmitoil-CoA Hidrolase/genética , Palmitoil-CoA Hidrolase/metabolismo , Filogenia
15.
An Acad Bras Cienc ; 91(2): e20180589, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31241701

RESUMO

The aim of this study was to evaluate the effects of subcutaneous calcium administration in post-partum dairy cows with respect to carbohydrate, protein and lipids metabolism, as well as its effects on milk composition. Twenty post-partum dairy cows were randomly divided into two groups (n=10): a control and a treated group with a single dose (150 mL) of calcium. Blood collection was performed on post-partum days 1, 2, 3, 7 and 10. In addition, we measured serum levels of total calcium, total proteins, albumin, globulins, glucose, cholesterol, triglycerides, as well as creatine kinase (CK) activity. We determined milk composition on post-partum days 5, 10 and 20. Serum total calcium levels was higher on post-partum days 3 and 7 in the treated group. Serum urea (day 3) and triglycerides (days 7 and 10) levels were higher in the treated group, as were CK activity levels at post-partum days 2 and 3. Serum glucose and cholesterol levels were lower on post-partum day 2 in treated animals. Fat (day 20) and lactose (day 10) content in milk samples were higher than in the treated animals. We concluded that treatment with calcium in cows during the post-partum period changes biochemical variables related to metabolism.


Assuntos
Cálcio/farmacologia , Metabolismo dos Carboidratos/efeitos dos fármacos , Bovinos/sangue , Metabolismo dos Lipídeos/efeitos dos fármacos , Leite/química , Proteínas/efeitos dos fármacos , Animais , Cálcio/administração & dosagem , Feminino , Período Pós-Parto , Proteínas/metabolismo
16.
BMC Genomics ; 20(1): 480, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31185888

RESUMO

BACKGROUND: Plasmids play an vital role in driving the rapid global spread of antimicrobial resistance and adaptation to changing ambient conditions. It has been suggested that the presence of plasmids can pose tremendous impacts on the host physiology. However, little is known regarding the contributions of carbapenemase-encoding plasmid carriage on the physiology and pathogenicity of hypervirulent K. pneumoniae (hvKP). RESULTS: Here we performed a transcriptomic analysis of hvKP with or without carbapenemase-encoding plasmid p24835-NDM5. The results had shown 683 genes with differential expression (false discovery rate, ≤0.001; > 2-fold change), of which 107 were up-regulated and 576 were down-regulated. Gene groups with functions relating to carbohydrate metabolism and multidrug efflux system were increased in genes with increased expression, and those relating to capsule biosynthesis and virulence factors were increased in the genes with decreased expression. In agreement with these changes, survival rate of TfpNDM-hvKP in the presence of normal human serum decreased, and competitive index (CI values) indicated significant fitness defects in the plasmid-carrying hvKP strain when co-cultured with its plasmid-free isogenic ancestor and the ATCC control. Moreover, the p24835-NDM5-containing hvKP strain retained its high neutrophil-mediated phagocytosis and murine lethality. CONCLUSION: These data indicate that hvKP responds to carbapenemase-encoding plasmid by altering the expression of genes involved in carbohydrate metabolism, antibiotic resistance, capsule biosynthesis and virulence expression. Apart from antibiotic resistance selective advantages, carbapenemase-encoding plasmid carriage may also lead to virulence change or adaption to specific habitats in hvKP strain.


Assuntos
Proteínas de Bactérias/genética , Perfilação da Expressão Gênica , Klebsiella pneumoniae/genética , Fenótipo , Plasmídeos/genética , beta-Lactamases/genética , Adulto , Animais , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Metabolismo dos Carboidratos/genética , Humanos , Cinética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/metabolismo , Klebsiella pneumoniae/patogenicidade , Camundongos , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Fagocitose , Virulência
17.
BMC Plant Biol ; 19(1): 255, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31195963

RESUMO

BACKGROUND: Understanding the mechanisms of crops in response to elevated CO2 concentrations is pivotal to estimating the impacts of climate change on the global agricultural production. Based on earlier results of the "doubling-CO2 concentration" experiments, many current climate models may overestimate the CO2 fertilization effect on crops, and meanwhile, underestimate the potential impacts of future climate change on global agriculture ecosystem when the atmospheric CO2 concentration goes beyond the optimal levels for crop growth. RESULTS: This study examined the photosynthetic response of soybean (Glycine max (L.) Merr.) to elevated CO2 concentration associated with changes in leaf structure, non-structural carbohydrates and nitrogen content with environmental growth chambers where the CO2 concentration was controlled at 400, 600, 800, 1000, 1200, 1400, 1600 ppm. We found CO2-induced down-regulation of leaf photosynthesis as evidenced by the consistently declined leaf net photosynthetic rate (An) with elevated CO2 concentrations. This down-regulation of leaf photosynthesis was evident in biochemical and photochemical processes since the maximum carboxylation rate (Vcmax) and the maximum electron transport rate (Jmax) were dramatically decreased at higher CO2 concentrations exceeding their optimal values of about 600 ppm and 400 ppm, respectively. Moreover, the down-regulation of leaf photosynthesis at high CO2 concentration was partially attributed to the reduced stomatal conductance (Gs) as demonstrated by the declines in stomatal density and stomatal area as well as the changes in the spatial distribution pattern of stomata. In addition, the smaller total mesophyll size (palisade and spongy tissues) and the lower nitrogen availability may also contribute to the down-regulation of leaf photosynthesis when soybean subjected to high CO2 concentration environment. CONCLUSIONS: Down-regulation of leaf photosynthesis associated with the changes in stomatal traits, mesophyll tissue size, non-structural carbohydrates, and nitrogen availability of soybean in response to future high atmospheric CO2 concentration and climate change.


Assuntos
Dióxido de Carbono/metabolismo , Nitrogênio/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Soja/metabolismo , Metabolismo dos Carboidratos , Mudança Climática , Regulação para Baixo , Folhas de Planta/anatomia & histologia , Estômatos de Plantas/anatomia & histologia , Soja/anatomia & histologia
18.
BMC Plant Biol ; 19(1): 262, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208336

RESUMO

BACKGROUND: Stored potato (Solanum tuberosum L.) tubers are sensitive to wet conditions that can cause rotting in long-term storage. To study the effect of water on the tuber surface during storage, microarray analysis, RNA-Seq profiling, qRT-PCR and phytohormone measurements were performed to study gene expression and hormone content in wet tubers incubated at two temperatures: 4 °C and 15 °C. The growth of the plants was also observed in a greenhouse after the incubation of tubers in wet conditions. RESULTS: Wet conditions induced a low-oxygen response, suggesting reduced oxygen availability in wet tubers at both temperatures when compared to that in the corresponding dry samples. Wet conditions induced genes coding for heat shock proteins, as well as proteins involved in fermentative energy production and defense against reactive oxygen species (ROS), which are transcripts that have been previously associated with low-oxygen stress in hypoxic or anoxic conditions. Wet treatment also induced senescence-related gene expression and genes involved in cell wall loosening, but downregulated genes encoding protease inhibitors and proteins involved in chloroplast functions and in the biosynthesis of secondary metabolites. Many genes involved in the production of phytohormones and signaling were also affected by wet conditions, suggesting altered regulation of growth by wet conditions. Hormone measurements after incubation showed increased salicylic acid (SA), abscisic acid (ABA) and auxin (IAA) concentrations as well as reduced production of jasmonate 12-oxo-phytodienoic acid (OPDA) in wet tubers. After incubation in wet conditions, the tubers produced fewer stems and more roots compared to controls incubated in dry conditions. CONCLUSIONS: In wet conditions, tubers invest in ROS protection and defense against the abiotic stress caused by reduced oxygen due to excessive water. Changes in ABA, SA and IAA that are antagonistic to jasmonates affect growth and defenses, causing induction of root growth and rendering tubers susceptible to necrotrophic pathogens. Water on the tuber surface may function as a signal for growth, similar to germination of seeds.


Assuntos
Armazenamento de Alimentos , Reguladores de Crescimento de Planta/metabolismo , Tubérculos/metabolismo , Solanum tuberosum/metabolismo , Metabolismo dos Carboidratos , Parede Celular/metabolismo , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Análise de Sequência com Séries de Oligonucleotídeos , Estresse Oxidativo , Tubérculos/crescimento & desenvolvimento , Metabolismo Secundário , Solanum tuberosum/crescimento & desenvolvimento , Transcriptoma , Água
19.
Gene ; 710: 210-217, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31176733

RESUMO

Low temperature is a key stress factor for the growth and development of wheat (Triticum aestivum L.), and glycometabolism plays an important role in plant cold tolerance. Our previous study identified trehalose 6-phosphate synthase 11 gene (TaTPS11), which had a significantly different expression pattern between a high freezing-tolerant wheat cultivar and a low freezing-tolerant wheat cultivar. In this study, TaTPS11 was isolated from a winter-hardy wheat cultivar (D1) and overexpressed in Arabidopsis thaliana to study its effect on cold tolerance in plants. Transgenic plants expressing TaTPS11 had lower sucrose content, higher starch content, and higher activity of key enzyme (sucrose phosphate synthase, sucrose synthase, and invertase) involved in sucrose metabolism. In addition, the expression level of sucrose non-fermenting 1-related kinase 1 (SnRK1), which catalyzes the sucrose in plants, increased in the TaTPS11-overexpressed plants. These results indicated that heterologous expression of TaTPS11 influenced carbohydrate metabolism in Arabidopsis plants. The resultant plants had a significantly higher survival rate after -5 °C treatment for 2 h and exhibited enhanced cold tolerance without unfavorable phenotypes compared to wild-type. Our findings indicated that manipulation of TaTPS11 improved cold tolerance in plants and TaTPS11 had potential values in wheat cold-tolerance breeding.


Assuntos
Arabidopsis/genética , Resposta ao Choque Frio , Monoéster Fosfórico Hidrolases/genética , Triticum/enzimologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Metabolismo dos Carboidratos , Regulação da Expressão Gênica de Plantas , Monoéster Fosfórico Hidrolases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Proteínas Serina-Treonina Quinases/genética , Reação em Cadeia da Polimerase em Tempo Real , Sacarose/metabolismo , Triticum/genética
20.
Plant Physiol Biochem ; 141: 456-465, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31247428

RESUMO

Alfalfa (Medicago sativa L.) is an important perennial legume and used as a forage crop worldwide, and has extensive resistance to various abiotic stresses. Nitric oxide (NO) plays a critical role in response to external and internal cues to regulate plant growth and development. However, endogenous NO-mediated molecular mechanisms of drought tolerance in alfalfa is poorly understood. To get a deeper insight into the regulate pathway of NO, RNA-Seq was used to profile transcriptome changes of alfalfa seedlings, which were treated with NO scavenger under normal and drought conditions. A total of 1,025 and 3,461 differently-expressed genes (FDR < 0.0001; fold change ≥ 2) were observed while NO absence under normal and drought conditions, respectively. Based on GO enrich and KEGG pathway analysis, we found NO absence induced photosynthesis, carbon fixation in photosynthetic organisms and primary metabolism were significantly up-enriched. Most oxidoreductase, dehydrogenase, reductase and transferase genes were down-regulated in the above processes. Moreover, NO absence restrained chlorophyll biosynthesis and decreased different sugar content. Therefore, this work provides insights into the mechanism that NO-mediated enhanced photosynthesis and carbohydrate metabolism in alfalfa under drought stress.


Assuntos
Metabolismo dos Carboidratos , Secas , Medicago sativa/enzimologia , Medicago sativa/fisiologia , Óxido Nítrico/química , Fotossíntese , Parede Celular/metabolismo , Clorofila/química , Cloroplastos/metabolismo , Perfilação da Expressão Gênica , Biblioteca Gênica , Plântula/enzimologia , Plântula/fisiologia , Análise de Sequência de RNA , Amido/química , Estresse Fisiológico , Sacarose/química
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