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Animal venoms are rich sources of neuroactive compounds, including anti-inflammatory, antiepileptic, and antinociceptive molecules. Our study identified a protonectin peptide from the wasp Parachartergus fraternus' venom using mass spectrometry and cDNA library construction. Using this peptide as a template, we designed a new peptide, protonectin-F, which exhibited higher antinociceptive activity and less motor impairment compared to protonectin. In drug interaction experiments with naloxone and AM251, Protonectin-F's activity was decreased by opioid and cannabinoid antagonism, two critical antinociception pathways. Further experiments revealed that this effect is most likely not induced by direct action on receptors but by activation of the descending pain control pathway. We noted that protonectin-F induced less tolerance in mice after repeated administration than morphine. Protonectin-F was also able to decrease TNF-α production in vitro and modulate the inflammatory response, which can further contribute to its antinociceptive activity. These findings suggest that protonectin-F may be a potential molecule for developing drugs to treat pain disorders with fewer adverse effects. Our results reinforce the biotechnological importance of animal venom for developing new molecules of clinical interest.
Assuntos
Peptídeos , Venenos de Vespas , Camundongos , Animais , Venenos de Vespas/química , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Morfina/farmacologia , Analgésicos Opioides , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Dor/tratamento farmacológico , Analgésicos/farmacologia , Analgésicos/uso terapêuticoRESUMO
A better understanding of the nutritional requirements of sheep, especially in terms of minerals, is crucial for improving production. We estimated the net requirements for Ca, P, K, Mg, and Na for gain (NCag, NPg, NKg, NMgg, and NNag) and maintenance (NCam, NPm, NKm, NMgm, and NNam) in male and female hair sheep. Six datasets with 248 individual records of hair sheep (139 non-castrated males, 75 castrated males and 34 females) were used to estimate the net macromineral requirements for gain. To estimate the net macromineral requirements for maintenance, 52 observations (26 non-castrated and 26 castrated males) were used. A meta-analytical approach was applied, using non-linear mixed effects models and the study as a random effect. Based on information criteria for model selection, heterogeneous variance functions were more likely to describe mineral requirements with a low level of model selection uncertainty. The adopted criteria allowed the choice of the best models to represent the macromineral requirements. The chosen models explained the observed variability in the sex, and the choices were based on a low level of uncertainty (w ≥ 0.90). Irrespective of sex, NCag and NPg decreased with increasing BW from 10 to 30 kg and average daily gain (ADG) of 150 g/day, ranging from 1.71-1.38; 1.83-1.57; 1.82-1.51 of Ca and 0.86-0.66; 0.92-0.78; 0.92-0.75 of P for non-castrated males, castrated males, and females, respectively. The NKg remained constant, with mean values of 0.26 g/day. The NNag range was 0.17 to 0.14 g/day for non-castrated males, 0.20 to 0.25 g/day for females, and constant (0.18 g/day) for castrated males with an increase in BW from 10 to 30 kg and an ADG of 150 g/day. Macromineral requirements for maintenance (mg/kg BW) and retention (%) were 23.70 and 54.30 for Ca, 25.33 and 79.80 for P, 11.74 and 5.00 for K, 2.63 and 8.50 for Mg, and 7.01 and 8.10 for Na for males. The International Committees did not provide inferences about the sex influence on mineral requirements. Our study indicates that sex is one factor that influences the macromineral requirements for gain. The information generated in this study can be used to optimize the mineral management of hair sheep in the growing phase in tropical regions.
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The cotton boll weevil (CBW) (Anthonomus grandis) is one of the major insect pests of cotton in Brazil. Currently, CBW control is mainly achieved by insecticide application, which is costly and insufficient to ensure effective crop protection. RNA interference (RNAi) has been used in gene function analysis and the development of insect control methods. However, some insect species respond poorly to RNAi, limiting the widespread application of this approach. Therefore, nanoparticles have been explored as an option to increase RNAi efficiency in recalcitrant insects. Herein, we investigated the potential of chitosan-tripolyphosphate (CS-TPP) and polyethylenimine (PEI) nanoparticles as a dsRNA carrier system to improve RNAi efficiency in the CBW. Different formulations of the nanoparticles with dsRNAs targeting genes associated with juvenile hormone metabolism, such as juvenile hormone diol kinase (JHDK), juvenile hormone epoxide hydrolase (JHEH), and methyl farnesoate hydrolase (MFE), were tested. The formulations were delivered to CBW larvae through injection (0.05-2 µg), and the expression of the target genes was evaluated using RT-qPCR. PEI nanoparticles increased targeted gene silencing compared with naked dsRNAs (up to 80%), whereas CS-TPP-dsRNA nanoparticles decreased gene silencing (0%-20%) or led to the same level of gene silencing as the naked dsRNAs (up to 50%). We next evaluated the effects of targeting a single gene or simultaneously targeting two genes via the injection of naked dsRNAs or dsRNAs complexed with PEI (500 ng) on CBW survival and phenotypes. Overall, the gene expression analysis showed that the treatments with PEI targeting either a single gene or multiple genes induced greater gene silencing than naked dsRNA (â¼60%). In addition, the injection of dsJHEH/JHDK, either naked or complexed with PEI, significantly affected CBW survival (18% for PEI nanoparticles and 47% for naked dsRNA) and metamorphosis. Phenotypic alterations, such as uncompleted pupation or malformed pupae, suggested that JHEH and JHDK are involved in developmental regulation. Moreover, CBW larvae treated with dsJHEH/JHDK + PEI (1,000 ng/g) exhibited significantly lower survival rate (55%) than those that were fed the same combination of naked dsRNAs (30%). Our findings demonstrated that PEI nanoparticles can be used as an effective tool for evaluating the biological role of target genes in the CBW as they increase the RNAi response.
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The coffee leaf miner (CLM) Leucoptera coffeella moth is a major threat to coffee production. Insect damage is related to the feeding behavior of the larvae on the leaf. During the immature life stages, the insect feeds in the mesophyll triggering necrosis and causing loss of photosynthetic capacity, defoliation and significant yield loss to coffee crops. Chemical control is used to support the coffee production chain, though market requirements move toward conscious consumption claiming for more sustainable methods. In this overview, we discuss aspects about the CLM concerning biology, history, geographical distribution, economic impacts, and the most relevant control strategies in progress. Insights to develop an integrated approach for a safer and eco-friendly control of the CLM are discussed here, including bio-extracts, nanotechnology, pheromones, and tolerant cultivars.
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In order to better understand the relationship between Flagelliform (Flag) spider silk molecular structural organization and the mechanisms of fiber assembly, it was designed and produced the Nephilengys cruentata Flag spidroin analogue rNcFlag2222. The recombinant proteins are composed by the elastic repetitive glycine-rich motifs (GPGGX/GGX) and the spacer region, rich in hydrophilic charged amino acids, present at the native silk spidroin. Using different approaches for nanomolecular protein analysis, the structural data of rNcFlag2222 recombinant proteins were compared in its fibrillar and in its fully solvated states. Based on the results was possible to identify the molecular structural dynamics of NcFlag2222 prior to and after fiber formation. Overal rNcFlag2222 shows a mixture of semiflexible and rigid conformations, characterized mostly by the presence of PPII, ß-turn and ß-sheet. These results agree with previous studies and bring insights about the molecular mechanisms that might driven Flag silk fibers assembly and elastomeric behavior.
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Plant expansins are structural cell wall-loosening proteins implicated in several developmental processes and responses to environmental constraints and pathogen infection. To date, there is limited information about the biological function of expansins-like B (EXLBs), one of the smallest and less-studied subfamilies of plant expansins. In the present study, we conducted a functional analysis of the wild Arachis AdEXLB8 gene in transgenic tobacco (Nicotiana tabacum) plants to clarify its putative role in mediating defense responses to abiotic and biotic stresses. First, its cell wall localization was confirmed in plants expressing an AdEXLB8:eGFP fusion protein, while nanomechanical assays indicated cell wall reorganization and reassembly due to AdEXLB8 overexpression without compromising the phenotype. We further demonstrated that AdEXLB8 increased tolerance not only to isolated abiotic (drought) and biotic (Sclerotinia sclerotiorum and Meloidogyne incognita) stresses but also to their combination. The jasmonate and abscisic acid signaling pathways were clearly favored in transgenic plants, showing an activated antioxidative defense system. In addition to modifications in the biomechanical properties of the cell wall, we propose that AdEXLB8 overexpression interferes with phytohormone dynamics leading to a defense primed state, which culminates in plant defense responses against isolated and combined abiotic and biotic stresses.
Assuntos
Arachis/genética , Nicotiana/fisiologia , Proteínas de Plantas/genética , Estresse Fisiológico/genética , Ácido Abscísico/metabolismo , Animais , Ascomicetos/patogenicidade , Fenômenos Biomecânicos , Parede Celular/genética , Parede Celular/metabolismo , Ciclopentanos/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Oxilipinas/metabolismo , Células Vegetais/metabolismo , Folhas de Planta/fisiologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Nicotiana/citologia , Nicotiana/genética , Nicotiana/microbiologia , Tylenchoidea/patogenicidadeRESUMO
The aim of this study was to estimate the energy and protein requirements for maintenance and growth of lambs. A total of 35 crossbreed Dorper × Santa Ines lambs [31 ± 1.28 kg of initial body weight (BW) and 4 months old] were distributed in a completely randomized design with three treatments groups (ad libitum, 30 and 60% of feed restriction). Five lambs were slaughtered at the beginning of the experimental trial as a reference group to estimate the initial empty BW (EBW) and body composition. When the animals of the ad libitum treatment reached a BW average of 47.2 kg, at day 84 of trial, all lambs were slaughtered. The feed restriction promoted reduction in body fat (P < 0.001) and energy concentration (P < 0.001), while protein showed a quadratic response (P = 0.05). The equations obtained for NEg and NPg requirements were 0.2984 × EBW0.75 × EBWG0.8069 and 248.617 × EBW-0.15546, respectively. The net energy (NEm) and protein (NPm) for maintenance were 71.00 kcal/kg EBW0.75/day and 1.76 g/kg EBW0.75/day, respectively. In conclusion, the NEg and NPg requirement for lambs with 30 kg of BW and 200 g of average daily gain (ADG) were 0.736 Mcal/day and 24.38 g/day, respectively. Our findings indicate that the NEm for crossbreed Dorper × Santa Ines lambs is similar to those recommended by the international committees; however, we support the hypothesis that the requirements for gain are lower.
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Rattlesnakes are easily recognized by a rattle on the tail. Despite the advances in molecular, morphological, and evolutionary studies about several aspects of rattles, there are no studies elucidating these nanoscale topographical features using high-resolution techniques. Here we propose a set of approaches to show these micro/nano surface features searching for patterns or hidden signatures. The results showed that the older rattle ring (segment 8) presented higher roughness values when compared to other segments. Cluster analysis allowed the observation of similarities/differences among some groups, which reinforced the strong discrepancy of the segment 8 when compared to the others and enable possible topographical transitions among each segment features, considering their linkages and Euclidean distances. Attractive forces and surface hardness were also significant increased on segment 8, while adhesion was significantly decreased on the segments 5, 6, and 7 compared to segment 1 (P < 0.05). Fourier transform infrared spectroscopy showed typical profiles of keratin spectra considering the amino acids present in this protein structure. Energy dispersive spectroscopy results indicated possible different molecular composition on each segment. These set of approaches applied on the present study represents an array of new possibilities towards the qualitative and quantitative analyses of this type of biomaterials enabling to address several structural, chemical and mechanical questions ongoing on scientific world.
Assuntos
Crotalus , Nanoestruturas , Animais , Materiais Biocompatíveis , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de SuperfícieRESUMO
The aim of the present study concerns the development, characterization and sensory evaluation of a dual-functional whey hydrolysate. Four concentrations of commercial pepsin (0.48%, 0.95%, 1.43%, 1.91% w/w) were evaluated. The hydrolyses curves and the Reversed-Phase High Performance Liquid Chromatography analyses showed a direct relationship between enzyme concentration and degree of hydrolysis. Through mass spectrometry 21 peptides were identified and 5 of them have never been described in the literature before. The hydrolysate produced (PC3) induced a vascular relaxation of 65.02% in phenylephrine-contracted rat aortic rings. PC3 powder presented a homogeneous aspect with a mean particle size of 86.39⯵m, high water solubility (>92%) in a wide pH range (1-12) and an increase of 33% in oil absorption capacity, when compared to the unhydrolyzed product. Sensory analysis showed a high acceptance (7.6 in a 9-point hedonic scale) of the hydrolysate among 100 consumers. The results brought the possibility of developing a whey hydrolysate with high vasorelaxant activity, great technological properties and sensory appeal, as an interesting dual-functional ingredient to be incorporated into food products.
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Comportamento do Consumidor/estatística & dados numéricos , Hidrolisados de Proteína/química , Proteínas do Soro do Leite/química , Animais , Aorta/efeitos dos fármacos , Bovinos , Cromatografia de Fase Reversa , Manipulação de Alimentos , Humanos , Hidrólise , Espectrometria de Massas , Hidrolisados de Proteína/farmacologia , Ratos , Vasodilatadores/química , Vasodilatadores/farmacologiaRESUMO
BACKGROUND: Silver nanoparticles (AgNPs), particularly those entrapped in polymeric nanosystems, have arisen as options for managing plant bacterial diseases. Among the biopolymers useful for the entrapment of AgNPs, chitosan is promising because of its low cost, good biocompatibility, antimicrobial properties and biodegradability. The present study aimed: (i) to greenly-synthesize AgNPs using different concentrations of aqueous extract of tomato leaves followed by entrapment of AgNPs with chitosan (CH-AgNPs); (ii) to characterize the optical, structural and biological properties of the nanosystems produced; (iii) to evaluate the antimicrobial activities of AgNPs and nanomaterials; and (iv) to assess the effectiveness of AgNPs and nanomaterials for controlling tomato bacterial wilt caused by Ralstonia solanacearum. RESULTS: Spherical and oval AgNPs had incipient colloidal instability, although the concentration of the tomato leaf extract influenced both size (< 87 nm) and the polydispersity index. Nanomaterials (< 271 nm in size) were characterized by a highly stable matrix of chitosan containing polydisperse AgNPs. Free AgNPs and CH-AgNPs were stable for up to 30 days, with no significant alteration in physicochemical parameters. The AgNPs and nanomaterials had antibacterial activity and decreased bacterial growth at micromolar concentrations after 48 h. Morphological changes in R. solanacearum cells were observed after treatment with CH-AgNPs. The application of CH-AgNPs at 256 µmol L-1 reduced the incidence of bacterial wilt in a partially resistant tomato genotype but not in the susceptible line. CONCLUSION: Greenly-synthesized chitosan-derived nanomaterials containing AgNPs produced with leaf extracts from their own species appear to comprise a promising and sustainable alternative in an integrated management approach aiming to reduce the yield losses caused by bacterial wilt. © 2019 Society of Chemical Industry.