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1.
Mol Biol Evol ; 40(2)2023 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-36721951

RESUMO

The evolutionary history of visual genes in Coleoptera differs from other well-studied insect orders, such as Lepidoptera and Diptera, as beetles have lost the widely conserved short-wavelength (SW) insect opsin gene that typically underpins sensitivity to blue light (∼440 nm). Duplications of the ancestral ultraviolet (UV) and long-wavelength (LW) opsins have occurred in many beetle lineages and have been proposed as an evolutionary route for expanded spectral sensitivity. The jewel beetles (Buprestidae) are a highly ecologically diverse and colorful family of beetles that use color cues for mate and host detection. In addition, there is evidence that buprestids have complex spectral sensitivity with up to five photoreceptor classes. Previous work suggested that opsin duplication and subfunctionalization of the two ancestral buprestid opsins, UV and LW, has expanded sensitivity to different regions of the light spectrum, but this has not yet been tested. We show that both duplications are likely unique to Buprestidae or the wider superfamily of Buprestoidea. To directly test photopigment sensitivity, we expressed buprestid opsins from two Chrysochroa species in Drosophila melanogaster and functionally characterized each photopigment type as UV- (356-357 nm), blue- (431-442 nm), green- (507-509 nm), and orange-sensitive (572-584 nm). As these novel opsin duplicates result in significantly shifted spectral sensitivities from the ancestral copies, we explored spectral tuning at four candidate sites using site-directed mutagenesis. This is the first study to directly test opsin spectral tuning mechanisms in the diverse and specious beetles.


Assuntos
Besouros , Opsinas , Animais , Opsinas/genética , Besouros/genética , Drosophila melanogaster/genética , Opsinas de Bastonetes/genética , Insetos , Filogenia
2.
An Acad Bras Cienc ; 96(3): e20230078, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38865507

RESUMO

This study evaluated the effects of broiler age (A) and levels of replacement (L) of control diet (CD) on the utilization of energy and nutrients of whole corn germ. 720 one-day-old broilers (b) were allocated at completely randomized design to six treatments and six replicates, in three assays: pre-starter (1-8 days, 10 b/cage), starter (15-22 days, 6 b/cage), and grower (28-35 days, 4 b/cage) phases. The treatments were: CD and four test diets (L): 100, 150, 200, 250, or 300 g kg-1 of the CD replaced by WCG levels. The data were adjusted to the response surface model. The stationary points for apparent energy metabolizable (AME) and AME corrected for nitrogen balance (AMEn) were: 4173 and 3591 kcal kg-1, respectively, and coefficients of gross energy (AMCGE), crude protein (AMCCP), dry matter (AMCDM), and ether extract (AMCEE) were: 49.3, 40.4, 72.6, and 61.3%, respectively; and Ileal digestibility coefficient of crude protein (IDCCP), dry matter (IDCDM), digestibility crude protein values (DCP), and digestibility dry matter value (DDM) were: 78.0, 57.96, 8.50, and 56.17%, respectively. The EP for AMEn was at 18 days of age, 28 g kg-1 WCG. There was a correlation between A and L on digestibility and metabolisability of nutrient's WCG.


Assuntos
Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Galinhas , Digestão , Metabolismo Energético , Íleo , Zea mays , Animais , Ração Animal/análise , Metabolismo Energético/fisiologia , Digestão/fisiologia , Zea mays/química , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Íleo/metabolismo , Íleo/fisiologia , Dieta/veterinária , Masculino , Distribuição Aleatória
3.
Am J Bot ; 110(9): e16214, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37475703

RESUMO

PREMISE: Plants survive in habitats with limited resource availability and contrasting environments by responding to variation in environmental factors through morphophysiological traits related to species performance in different ecosystems. However, how different plant strategies influence the megadiversity of tropical species has remained a knowledge gap. METHODS: We analyzed variations in 27 morphophysiological traits of leaves and secondary xylem in Erythroxylum pulchrum and Tapirira guianensis, which have the highest absolute dominance in these physiognomies and occur together in areas of restinga and dense ombrophilous forest to infer water-transport strategies of Atlantic Forest woody plants. RESULTS: The two species presented different sets of morphophysiological traits, strategies to avoid embolism and ensure water transport, in different phytophysiognomies. Tapirira guianensis showed possible adaptations influenced by phytophysiognomy, while E. pulchrum showed less variation in the set of characteristics between different phytophysiognomies. CONCLUSIONS: Our results provide essential tools to understand how the environment can modulate morphofunctional traits and how each species adjusts differently to adapt to different phytophysiognomies. In this sense, the results for these species reveal new species-specific responses in the tropical forest. Such knowledge is a prerequisite to predict future development of the most vulnerable forests as climate changes.


Assuntos
Ecossistema , Árvores , Árvores/fisiologia , Clima Tropical , Água/fisiologia , Florestas , Folhas de Planta/fisiologia
4.
Physiol Plant ; 175(2): e13877, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36811487

RESUMO

Callose is a polymer deposited on the cell wall and is necessary for plant growth and development. Callose is synthesized by genes from the glucan synthase-like family (GSL) and dynamically responds to various types of stress. Callose can inhibit pathogenic infection, in the case of biotic stresses, and maintain cell turgor and stiffen the plant cell wall in abiotic stresses. Here, we report the identification of 23 GSL genes (GmGSL) in the soybean genome. We performed phylogenetic analyses, gene structure prediction, duplication patterns, and expression profiles on several RNA-Seq libraries. Our analyses show that WGD/Segmental duplication contributed to expanding this gene family in soybean. Next, we analyzed the callose responses in soybean under abiotic and biotic stresses. The data show that callose is induced by both osmotic stress and flagellin 22 (flg22) and is related to the activity of ß-1,3-glucanases. By using RT-qPCR, we evaluated the expression of GSL genes during the treatment of soybean roots with mannitol and flg22. The GmGSL23 gene was upregulated in seedlings treated with osmotic stress or flg22, showing the essential role of this gene in the soybean defense response to pathogenic organisms and osmotic stress. Our results provide an important understanding of the role of callose deposition and regulation of GSL genes in response to osmotic stress and flg22 infection in soybean seedlings.


Assuntos
Arabidopsis , Arabidopsis/metabolismo , Plântula/metabolismo , Glycine max/metabolismo , Flagelina/genética , Flagelina/metabolismo , Filogenia , Manitol/metabolismo , Regulação da Expressão Gênica de Plantas
5.
Eur J Appl Physiol ; 123(8): 1599-1625, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36917254

RESUMO

Respiratory function has become a global health priority. Not only is chronic respiratory disease a leading cause of worldwide morbidity and mortality, but the COVID-19 pandemic has heightened attention on respiratory health and the means of enhancing it. Subsequently, and inevitably, the respiratory system has become a target of the multi-trillion-dollar health and wellness industry. Numerous commercial, respiratory-related interventions are now coupled to therapeutic and/or ergogenic claims that vary in their plausibility: from the reasonable to the absurd. Moreover, legitimate and illegitimate claims are often conflated in a wellness space that lacks regulation. The abundance of interventions, the range of potential therapeutic targets in the respiratory system, and the wealth of research that varies in quality, all confound the ability for health and exercise professionals to make informed risk-to-benefit assessments with their patients and clients. This review focuses on numerous commercial interventions that purport to improve respiratory health, including nasal dilators, nasal breathing, and systematized breathing interventions (such as pursed-lips breathing), respiratory muscle training, canned oxygen, nutritional supplements, and inhaled L-menthol. For each intervention we describe the premise, examine the plausibility, and systematically contrast commercial claims against the published literature. The overarching aim is to assist health and exercise professionals to distinguish science from pseudoscience and make pragmatic and safe risk-to-benefit decisions.


Assuntos
COVID-19 , Doença Pulmonar Obstrutiva Crônica , Humanos , Pandemias , Pseudociência , Exercícios Respiratórios
6.
An Acad Bras Cienc ; 95(2): e20210330, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37585893

RESUMO

This study investigated the effect of vegetable and fish oils with different n-3 / n-6 PUFAS ratios on the lipoprotein profile and on the development of murine breast cancer 4T1. Female Balb/c mice (6-7 weeks) received diets containing 4.0% fat during seven weeks. On the fourth week, animals were inoculated into the posterior left flank with 2.5 × 106 4T1 cells. Body weight and food intake were registered and the profile serum lipoproteins was determined. Tumor volume, histopathological and immunohistochemical studies, myeloperoxidase and N-acetylglucosaminidase activities, TNF-α, hemoglobin and VEGF levels were analysed. The highest n-3 / n-6 ratio was found in fish oil (15.8:1), followed by linseed (2.4:1), canola (1:2.1) and soybean (1:9.4) oils. Body weight, food and caloric intake, lipoprotein profile, tumor weight, tumor evolution and histopathological analysis were not different. Canola oil increased cell proliferation when compared to soybean oil, and fish oil changed the inflammatory response and increased VEGF in tumors compared to other groups. The type of fatty acid and the high ratio of n-3 / n-6 PUFAs in the diet influenced cell proliferation and inflammation in the tumor differentially, highlighting the increase of neutrophils and VEGF levels in animals fed on fish oil.


Assuntos
Ácidos Graxos Ômega-3 , Fator A de Crescimento do Endotélio Vascular , Animais , Feminino , Camundongos , Óleos de Plantas , Gorduras na Dieta , Ácidos Graxos Ômega-3/análise , Óleos de Peixe/metabolismo , Ácidos Graxos/análise , Lipoproteínas , Peso Corporal
7.
Int J Mol Sci ; 24(12)2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37373206

RESUMO

For targeted protein panels, the ability to specifically assay post-translational modifications (PTMs) in a quantitative, sensitive, and straightforward manner would substantially advance biological and pharmacological studies. The present study highlights the effectiveness of the Affi-BAMS™ epitope-directed affinity bead capture/MALDI MS platform for quantitatively defining complex PTM marks of H3 and H4 histones. Using H3 and H4 histone peptides and isotopically labelled derivatives, this affinity bead and MALDI MS platform achieves a range of >3 orders of magnitude with a technical precision CV of <5%. Using nuclear cellular lysates, Affi-BAMS PTM-peptide capture resolves heterogeneous histone N-terminal PTMs with as little as 100 µg of starting material. In an HDAC inhibitor and MCF7 cell line model, the ability to monitor dynamic histone H3 acetylation and methylation events is further demonstrated (including SILAC quantification). Affi-BAMS (and its capacity for the multiplexing of samples and target PTM-proteins) thus provides a uniquely efficient and effective approach for analyzing dynamic epigenetic histone marks, which is critical for the regulation of chromatin structure and gene expression.


Assuntos
Histonas , Proteômica , Histonas/metabolismo , Espectrometria de Massas em Tandem , Processamento de Proteína Pós-Traducional , Código das Histonas , Peptídeos/metabolismo , Acetilação
8.
Exp Physiol ; 107(12): 1477-1492, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36177711

RESUMO

NEW FINDINGS: What is the central question of this study? Is the stabilising function of the diaphragm altered differentially in response to involuntary augmented breaths induced with or without lower-limb movements? What is the main finding and its importance? At equivalent levels of ventilation, the diaphragm generated higher passive pressure but moved significantly less during incremental cycle ergometry compared with progressive hypercapnia. Diaphragm excursion velocity and power output did not differ between the two tasks. These findings imply that the power output of the diaphragm during stabilising tasks involving the lower limbs may be preserved via coordinated changes in contractile shortening. ABSTRACT: Activity of key respiratory muscles, such as the diaphragm, must balance the demands of ventilation with the maintenance of stable posture. Our aim was to test whether the stabilising function of the diaphragm would be altered differentially in response to involuntary augmented breaths induced with or without lower-limb movements. Ten healthy volunteers (age 21 (2) years; mean (SD)) performed progressive CO2 -rebreathe (5% CO2 , 95% O2 ) followed 20 min later by incremental cycle exercise (15-30 W/min), both in a semi-recumbent position. Ventilatory indices, intrathoracic pressures and ultrasonographic measures of diaphragm shortening were assessed before, during and after each task. From rest to iso-time, inspiratory tidal volume and minute ventilation increased two- to threefold. At equivalent levels of tidal volume and minute ventilation, mean inspiratory transdiaphragmatic pressure ( P ¯ di ${\bar P_{{\rm{di}}}}$ ) was consistently higher during exercise compared with CO2 -rebreathe due to larger increases in gastric pressure and the passive component of P ¯ di ${\bar P_{{\rm{di}}}}$ (i.e., mechanical output due to static contractions), and yet diaphragm excursion was consistently lower. This lower excursion during exercise was accompanied by a reduction in excursion time with no difference in the active component of P ¯ di ${\bar P_{{\rm{di}}}}$ . Consequently, the rates of increase in excursion velocity (excursion/time) and power output (active P ¯ di ${\bar P_{{\rm{di}}}}$ × velocity) did not differ between the two tasks. In conclusion, the power output of the human diaphragm during dynamic lower-limb exercise appears to be preserved via coordinated changes in contractile shortening. The findings may have significance in settings where the ventilatory and stabilising functions of the diaphragm must be balanced (e.g., rehabilitation).


Assuntos
Dióxido de Carbono , Diafragma , Humanos , Adulto Jovem , Adulto , Diafragma/fisiologia , Músculos Respiratórios/fisiologia , Respiração , Pulmão/fisiologia , Extremidade Inferior
9.
An Acad Bras Cienc ; 94(suppl 3): e20201066, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36074424

RESUMO

We investigated the effect of dietary supplementation with kinkan orange on growth, adiposity, metabolic parameters, and oxidative stress in rats with diet-induced hypercholesterolemia. Female Wistar rats (6-8 weeks) were fed a AIN-93M diet (Control); AIN-93M diet containing 5% kinkan orange (CTkinkan); Hypercholesterolemic diet, containing 1% cholesterol and 25% fat (Hyper); or Hypercholesterolemic diet containing 5% kinkan orange (Hyperkinkan). Hypercholesterolemic diet increased body weight, adiposity, serum alanine transaminase (ALT), creatinine, cholesterol and triglycerides, hepatic total lipids, cholesterol, and triglycerides, and hepatic oxidative stress. Supplementation with kinkan reduced the serum and hepatic lipid content, decreased serum ALT, besides improving the antioxidant status in liver tissue of hypercholesterolemic animals. Moreover, HDL-cholesterol increased in both groups supplemented with kinkan orange (CTkinkan and Hyperkinkan). Our data suggest that diet supplementation with kinkan orange may consist of a valid strategy to prevent or reduce dyslipidemia and oxidative stress in hypercholesterolemic rats.


Assuntos
Citrus sinensis , Dislipidemias , Alanina Transaminase , Animais , Colesterol , Citrus sinensis/metabolismo , Dislipidemias/tratamento farmacológico , Dislipidemias/metabolismo , Dislipidemias/prevenção & controle , Feminino , Fígado , Obesidade/metabolismo , Estresse Oxidativo , Ratos , Ratos Wistar , Triglicerídeos
10.
J Neurosci ; 40(42): 8055-8069, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-32948676

RESUMO

Members of the arrestin superfamily have great propensity of self-association, but the physiological significance of this phenomenon is unclear. To determine the biological role of visual arrestin-1 oligomerization in rod photoreceptors, we expressed mutant arrestin-1 with severely impaired self-association in mouse rods and analyzed mice of both sexes. We show that the oligomerization-deficient mutant is capable of quenching rhodopsin signaling normally, as judged by electroretinography and single-cell recording. Like wild type, mutant arrestin-1 is largely excluded from the outer segments in the dark, proving that the normal intracellular localization is not due the size exclusion of arrestin-1 oligomers. In contrast to wild type, supraphysiological expression of the mutant causes shortening of the outer segments and photoreceptor death. Thus, oligomerization reduces the cytotoxicity of arrestin-1 monomer, ensuring long-term photoreceptor survival.SIGNIFICANCE STATEMENT Visual arrestin-1 forms dimers and tetramers. The biological role of its oligomerization is unclear. To test the role of arrestin-1 self-association, we expressed oligomerization-deficient mutant in arrestin-1 knock-out mice. The mutant quenches light-induced rhodopsin signaling like wild type, demonstrating that in vivo monomeric arrestin-1 is necessary and sufficient for this function. In rods, arrestin-1 moves from the inner segments and cell bodies in the dark to the outer segments in the light. Nonoligomerizing mutant undergoes the same translocation, demonstrating that the size of the oligomers is not the reason for arrestin-1 exclusion from the outer segments in the dark. High expression of oligomerization-deficient arrestin-1 resulted in rod death. Thus, oligomerization reduces the cytotoxicity of high levels of arrestin-1 monomer.


Assuntos
Arrestinas/metabolismo , Arrestinas/fisiologia , Adaptação Ocular , Animais , Arrestinas/genética , Sobrevivência Celular , Eletrorretinografia , Feminino , Transdução de Sinal Luminoso , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Mutação/genética , Retina/anatomia & histologia , Retina/crescimento & desenvolvimento , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Rodopsina/fisiologia
11.
World J Urol ; 39(3): 953-962, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32388784

RESUMO

PURPOSE: To quantitatively assess the benefit-risk ratio on the efficacy and safety of all phosphodiesterase type 5 inhibitors (PDE5i) in men with erectile dysfunction. METHODS: A systematic review with network meta-analysis, surface under the cumulative ranking analysis and stochastic multicriteria acceptability analyses were performed. Searches were conducted in Pubmed, Scopus, Web of Science without limits for time-frame or language. Randomized controlled trials evaluating the efficacy or safety of any PDE5i compared to a placebo or to other PDE5i in males with erectile disfunction were included. RESULTS: Overall, 184 articles representing 179 randomized controlled trials (50,620 patients) were included. All PDE5i were significantly more efficient than placebo. Sildenafil 25 mg was statistically superior to all interventions in enhancing IIEF (with a 98% probability of being the most effective treatment), followed by sildenafil 50 mg (80% of probability). Taladafil 10 mg and 20 mg also presented good profiles (73% and 76%, respectively). Avanafil and lodenafil were less effective interventions. Mirodenafil 150 mg was the treatment that caused more adverse events, especially flushing and headaches. Sildenafil 100 mg was more related to visual disorders, while vardenafil and udenafil were more prone to cause nasal congestion. CONCLUSION: Sildenafil at low doses and tadalafil should be the first therapeutic options. Avanafil, lodenafil and mirodenafil use are hardly justified given the lack of expressive efficacy or high rates of adverse events.


Assuntos
Técnicas de Apoio para a Decisão , Disfunção Erétil/tratamento farmacológico , Inibidores da Fosfodiesterase 5/administração & dosagem , Administração Oral , Humanos , Masculino , Metanálise em Rede , Inibidores da Fosfodiesterase 5/efeitos adversos , Resultado do Tratamento
12.
Int J Mol Sci ; 21(6)2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32188029

RESUMO

The ability to quantitatively probe diverse panels of proteins and their post-translational modifications (PTMs) across multiple samples would aid a broad spectrum of biological, biochemical and pharmacological studies. We report a novel, microarray analytical technology that combines immuno-affinity capture with Matrix Assisted Laser Desorption Ionization Mass Spectrometry (MALDI MS), which is capable of supporting highly multiplexed, targeted proteomic assays. Termed "Affinity-Bead Assisted Mass Spectrometry" (Affi-BAMS), this LC-free technology enables development of highly specific and customizable assay panels for simultaneous profiling of multiple proteins and PTMs. While affinity beads have been used previously in combination with MS, the Affi-BAMS workflow uses enrichment on a single bead that contains one type of antibody, generally capturing a single analyte (protein or PTM) while having enough binding capacity to enable quantification within approximately 3 orders of magnitude. The multiplexing capability is achieved by combining Affi-BAMS beads with different protein specificities. To enable screening of bead-captured analytes by MS, we further developed a novel method of performing spatially localized elution of targets from individual beads arrayed on a microscope slide. The resulting arrays of micro spots contain highly concentrated analytes localized within 0.5 mm diameter spots that can be directly measured using MALDI MS. While both intact proteins and protein fragments can be monitored by Affi-BAMS, we initially focused on applying this technology for bottom-up proteomics to enable screening of hundreds of samples per day by combining the robust magnetic bead-based workflow with the high throughput nature of MALDI MS acquisition. To demonstrate the variety of applications and robustness of Affi-BAMS, several studies are presented that focus on the response of 4EBP1, RPS6, ERK1/ERK2, mTOR, Histone H3 and C-MET to stimuli including rapamycin, H2O2, EPO, SU11274, Staurosporine and Vorinostat.


Assuntos
Análise em Microsséries/métodos , Proteômica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Cromatina , Humanos , Peróxido de Hidrogênio , Isótopos , Peptídeo Hidrolases/química , Mutação Puntual , Processamento de Proteína Pós-Traducional , Proteínas/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Transdução de Sinais
13.
Curr Sports Med Rep ; 19(8): 290-297, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32769665

RESUMO

Regular physical activity decreases the risk of cardiovascular disease, type II diabetes, obesity, certain cancers, and all-cause mortality. Nevertheless, there is mounting evidence that extreme exercise behaviors may be detrimental to human health. This review collates several decades of literature on the physiology and pathophysiology of ultra-marathon running, with emphasis on the cardiorespiratory implications. Herein, we discuss the prevalence and clinical significance of postrace decreases in lung function and diffusing capacity, respiratory muscle fatigue, pulmonary edema, biomarkers of cardiac injury, left/right ventricular dysfunction, and chronic myocardial remodeling. The aim of this article is to inform risk stratification for ultra-marathon and to edify best practice for personnel overseeing the events (i.e., race directors and medics).


Assuntos
Sistema Cardiovascular/fisiopatologia , Corrida de Maratona/fisiologia , Sistema Respiratório/fisiopatologia , Biomarcadores/sangue , Humanos , Fatores de Risco
14.
Planta ; 250(4): 1325-1337, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31273443

RESUMO

MAIN CONCLUSION: Identification of the structural changes and cell wall-related genes likely involved in cell wall extension, cellular water balance and cell wall biosynthesis on embryonic axes during germination of soybean seeds. Cell wall is a highly organized and dynamic structure that provides mechanical support for the cell. During seed germination, the cell wall is critical for cell growth and seedling establishment. Although seed germination has been widely studied in several species, key aspects regarding the regulation of cell wall dynamics in germinating embryonic axes remain obscure. Here, we characterize the gene expression patterns of cell wall pathways and investigate their impact on the cell wall dynamics of embryonic axes of germinating soybean seeds. We found 2143 genes involved in cell wall biosynthesis and assembly in the soybean genome. Key cell wall genes were highly expressed at specific germination stages, such as expansins, UDP-Glc epimerases, GT family, cellulose synthases, peroxidases, arabinogalactans, and xyloglucans-related genes. Further, we found that embryonic axes grow through modulation of these specific cell wall genes with no increment in biomass. Cell wall structural analysis revealed a defined pattern of cell expansion and an increase in cellulose content during germination. In addition, we found a clear correlation between these structural changes and expression patterns of cell wall genes during germination. Taken together, our results provide a better understanding of the complex transcriptional regulation of cell wall genes that drive embryonic axes growth and expansion during soybean germination.


Assuntos
Regulação da Expressão Gênica de Plantas , Genoma de Planta/genética , Glycine max/genética , Parede Celular/metabolismo , Germinação , Plântula/genética , Plântula/crescimento & desenvolvimento , Sementes/genética , Sementes/crescimento & desenvolvimento , Glycine max/crescimento & desenvolvimento
15.
PLoS Pathog ; 13(7): e1006469, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28759640

RESUMO

The repeat region of the Plasmodium falciparum circumsporozoite protein (CSP) is a major vaccine antigen because it can be targeted by parasite neutralizing antibodies; however, little is known about this interaction. We used isothermal titration calorimetry, X-ray crystallography and mutagenesis-validated modeling to analyze the binding of a murine neutralizing antibody to Plasmodium falciparum CSP. Strikingly, we found that the repeat region of CSP is bound by multiple antibodies. This repeating pattern allows multiple weak interactions of single FAB domains to accumulate and yield a complex with a dissociation constant in the low nM range. Because the CSP protein can potentially cross-link multiple B cell receptors (BCRs) we hypothesized that the B cell response might be T cell independent. However, while there was a modest response in mice deficient in T cell help, the bulk of the response was T cell dependent. By sequencing the BCRs of CSP-repeat specific B cells in inbred mice we found that these cells underwent somatic hypermutation and affinity maturation indicative of a T-dependent response. Last, we found that the BCR repertoire of responding B cells was limited suggesting that the structural simplicity of the repeat may limit the breadth of the immune response.


Assuntos
Anticorpos Antiprotozoários/imunologia , Linfócitos B/imunologia , Vacinas Antimaláricas/imunologia , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Linfócitos T/imunologia , Animais , Afinidade de Anticorpos , Cristalografia por Raios X , Feminino , Humanos , Vacinas Antimaláricas/administração & dosagem , Vacinas Antimaláricas/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Plasmodium falciparum/química , Plasmodium falciparum/genética , Proteínas de Protozoários/administração & dosagem , Proteínas de Protozoários/química , Proteínas de Protozoários/genética
16.
Plant Physiol ; 178(1): 358-371, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29997180

RESUMO

Circadian clocks drive rhythms with a period near 24 h, but the molecular basis of the regulation of the period of the circadian clockis poorly understood. We previously demonstrated that metabolites affect the free-running period of the circadian oscillator of Arabidopsis (Arabidopsis thaliana), with endogenous sugars acting as an accelerator and exogenous nicotinamide acting as a brake. Changes in circadian oscillator period are thought to adjust the timing of biological activities through the process of entrainment, in which the circadian oscillator becomes synchronized to rhythmic signals such as light and dark cycles as well as changes in internal metabolism. To identify the molecular components associated with the dynamic adjustment of circadian period, we performed a forward genetic screen. We identified Arabidopsis mutants that were either period insensitive to nicotinamide (sin) or period oversensitive to nicotinamide (son). We mapped son1 to BIG, a gene of unknown molecular function that was shown previously to play a role in light signaling. We found that son1 has an early entrained phase, suggesting that the dynamic alteration of circadian period contributes to the correct timing of biological events. Our data provide insight into how the dynamic period adjustment of circadian oscillators contributes to establishing a correct phase relationship with the environment and show that BIG is involved in this process.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Proteínas de Ligação a Calmodulina/genética , Relógios Circadianos/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Cálcio/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Relógios Circadianos/efeitos da radiação , Ritmo Circadiano/genética , Ritmo Circadiano/efeitos da radiação , Luz , Plantas Geneticamente Modificadas
17.
Clin Exp Rheumatol ; 37(2): 306-309, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30620271

RESUMO

OBJECTIVES: The objective of the study was to compare the production of metalloproteinases (MMP)-1, -3 and interleukin (IL)-6 by fibroblast-like synoviocytes (FLS) derived from synovial fluid (FD-FLS), and FLS derived from synovial tissue (TD-FLS) of patients with primary osteoarthritis (OA). The more accessible FD-FLS could facilitate the study of the role of these cells in OA pathophysiology. METHODS: MMP-1, MMP-3, and IL-6 levels were measured in the supernatant culture at baseline and 22 hours after stimulation with TNF-α and IL-1 ß. RESULTS: There was no difference at baseline between MMP-1, MMP-3 and IL-6 production by FD-FLS and TDFLS. Analogous to baseline, stimulation of FD-FLS and TD-FLS with IL-1ß and TNF-α did not result in difference on MMP-3 and IL-6 production. However, TD-FLS produced more MMP-1 than FD-FLS after stimulation with IL-1ß (p=0.01). Additionally, there was a positive correlation for production of MMP-1, MMP-3 and IL-6 between FD-FLS and TD-FLS (r=0.40 and p<0.0008; r=0.66 and p<0.0001; r=0.76 and p<0.0001, respectively). Supporting this statistical significant positive correlation, the Bland-Altman plotting, showed a homogeneous distribution of the values and low mean disagreement rates between all results of FD-FLS and TD-FLS (23.1%, 56.8% and 48.1%, respectively). CONCLUSIONS: Our data demonstrated functional similarity between FD-FLS and TD-FLS and support the use of a more accessible source of FLS for the study of the pathogenesis of joint destruction and therapeutic targets in primary OA.


Assuntos
Interleucina-6/sangue , Metaloproteases/sangue , Osteoartrite , Líquido Sinovial/metabolismo , Membrana Sinovial/metabolismo , Sinoviócitos , Células Cultivadas , Fibroblastos , Humanos , Interleucina-8 , Osteoartrite/metabolismo
18.
Acta Neuropsychiatr ; 31(3): 151-158, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30914071

RESUMO

OBJECTIVE: Depression is a common, serious, but under-recognised problem in multiple sclerosis (MS). The primary objective of this study was to assess whether a rapid visual analogue screening tool for depression could operate as a quick and reliable screening method for depression, in patients with MS. METHOD: Patients attending a regional MS outpatient clinic completed the Emotional Thermometer 7 tool (ET7), the Hospital Anxiety and Depression Scale - Depression Subscale (HADS-D) and the Major Depression Inventory (MDI) to establish a Diagnostic and Statistical Manual, 4th edition (DSM-IV) diagnosis of Major Depression. Full ET7, briefer subset ET4 version and depression and distress thermometers alone were compared with HADS-D and MDI. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and receiver operating characteristic (ROC) curve were calculated to compare the performance of all the screening tools. RESULTS: In total, 190 patients were included. ET4 performed well as a 'rule-out' screening step (sensitivity 0.91, specificity 0.72, NPV 0.98, PPV 0.32). ET4 performance was comparable to HADS-D (sensitivity 0.96, specificity 0.77, NPV 0.99, PPV 0.37) without need for clinician scoring. The briefer ET4 performed as well as the full ET7. CONCLUSION: ET are quick, sensitive and useful screening tools for depression in this MS population, to be complemented by further questioning or more detailed psychiatric assessment where indicated. Given that ET4 and ET7 perform equally well, we recommend the use of ET4 as it is briefer. It has the potential to be widely implemented across busy neurology clinics to assist in depression screening in this under diagnosed group.


Assuntos
Depressão/diagnóstico , Depressão/psicologia , Emoções , Esclerose Múltipla/complicações , Esclerose Múltipla/psicologia , Valor Preditivo dos Testes , Adulto , Depressão/complicações , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Psicometria , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Escala Visual Analógica , Adulto Jovem
19.
Naturwissenschaften ; 105(5-6): 32, 2018 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-29744587

RESUMO

In "Polarisation vision: overcoming challenges of working with a property of light we barely see" (Foster et al. 2018) we provide a basic description of how Stokes parameters can be estimated and used to calculate the angle of polarisation (AoP).

20.
Naturwissenschaften ; 105(3-4): 27, 2018 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-29589169

RESUMO

In recent years, the study of polarisation vision in animals has seen numerous breakthroughs, not just in terms of what is known about the function of this sensory ability, but also in the experimental methods by which polarisation can be controlled, presented and measured. Once thought to be limited to only a few animal species, polarisation sensitivity is now known to be widespread across many taxonomic groups, and advances in experimental techniques are, in part, responsible for these discoveries. Nevertheless, its study remains challenging, perhaps because of our own poor sensitivity to the polarisation of light, but equally as a result of the slow spread of new practices and methodological innovations within the field. In this review, we introduce the most important steps in designing and calibrating polarised stimuli, within the broader context of areas of current research and the applications of new techniques to key questions. Our aim is to provide a constructive guide to help researchers, particularly those with no background in the physics of polarisation, to design robust experiments that are free from confounding factors.


Assuntos
Luz , Projetos de Pesquisa/normas , Visão Ocular , Animais , Estimulação Luminosa
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