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1.
Genes Dev ; 37(7-8): 259-260, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-37045607

RESUMO

Cohesin is an ATPase that drives chromosome organization through the generation of intramolecular loops and sister chromatid cohesion. Cohesin's ATPase is stimulated by Scc2 binding but attenuated by acetylation of its Smc3 subunit. In this issue of Genes & Development, Boardman and colleagues (pp. 277-290) take a genetic approach to generate a mechanistic model for the opposing regulation of cohesin's ATPase by Scc2 and Smc3 acetylation. Their findings provide in vivo insight into how this important genome organizer functions in vivo.


Assuntos
Adenosina Trifosfatases , Proteínas de Saccharomyces cerevisiae , Adenosina Trifosfatases/metabolismo , Proteínas de Ciclo Celular/metabolismo , Cromatina , Cromátides/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
2.
Nature ; 615(7954): 945-953, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36890234

RESUMO

Adhesion G-protein-coupled receptors (aGPCRs) bear notable similarity to Notch proteins1, a class of surface receptors poised for mechano-proteolytic activation2-4, including an evolutionarily conserved mechanism of cleavage5-8. However, so far there is no unifying explanation for why aGPCRs are autoproteolytically processed. Here we introduce a genetically encoded sensor system to detect the dissociation events of aGPCR heterodimers into their constituent N-terminal and C-terminal fragments (NTFs and CTFs, respectively). An NTF release sensor (NRS) of the neural latrophilin-type aGPCR Cirl (ADGRL)9-11, from Drosophila melanogaster, is stimulated by mechanical force. Cirl-NRS activation indicates that receptor dissociation occurs in neurons and cortex glial cells. The release of NTFs from cortex glial cells requires trans-interaction between Cirl and its ligand, the Toll-like receptor Tollo (Toll-8)12, on neural progenitor cells, whereas expressing Cirl and Tollo in cis suppresses dissociation of the aGPCR. This interaction is necessary to control the size of the neuroblast pool in the central nervous system. We conclude that receptor autoproteolysis enables non-cell-autonomous activities of aGPCRs, and that the dissociation of aGPCRs is controlled by their ligand expression profile and by mechanical force. The NRS system will be helpful in elucidating the physiological roles and signal modulators of aGPCRs, which constitute a large untapped reservoir of drug targets for cardiovascular, immune, neuropsychiatric and neoplastic diseases13.


Assuntos
Adesão Celular , Proteínas de Drosophila , Drosophila melanogaster , Ligantes , Proteólise , Receptores Acoplados a Proteínas G , Receptores de Peptídeos , Animais , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/metabolismo , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Peptídeos/química , Receptores de Peptídeos/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Células-Tronco Neurais/metabolismo
3.
Proc Natl Acad Sci U S A ; 121(18): e2322692121, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38652744

RESUMO

Food intake and energy balance are tightly regulated by a group of hypothalamic arcuate neurons expressing the proopiomelanocortin (POMC) gene. In mammals, arcuate-specific POMC expression is driven by two cis-acting transcriptional enhancers known as nPE1 and nPE2. Because mutant mice lacking these two enhancers still showed hypothalamic Pomc mRNA, we searched for additional elements contributing to arcuate Pomc expression. By combining molecular evolution with reporter gene expression in transgenic zebrafish and mice, here, we identified a mammalian arcuate-specific Pomc enhancer that we named nPE3, carrying several binding sites also present in nPE1 and nPE2 for transcription factors known to activate neuronal Pomc expression, such as ISL1, NKX2.1, and ERα. We found that nPE3 originated in the lineage leading to placental mammals and remained under purifying selection in all mammalian orders, although it was lost in Simiiformes (monkeys, apes, and humans) following a unique segmental deletion event. Interestingly, ablation of nPE3 from the mouse genome led to a drastic reduction (>70%) in hypothalamic Pomc mRNA during development and only moderate (<33%) in adult mice. Comparison between double (nPE1 and nPE2) and triple (nPE1, nPE2, and nPE3) enhancer mutants revealed the relative contribution of nPE3 to hypothalamic Pomc expression and its importance in the control of food intake and adiposity in male and female mice. Altogether, these results demonstrate that nPE3 integrates a tripartite cluster of partially redundant enhancers that originated upon a triple convergent evolutionary process in mammals and that is critical for hypothalamic Pomc expression and body weight homeostasis.


Assuntos
Peso Corporal , Ingestão de Alimentos , Elementos Facilitadores Genéticos , Hipotálamo , Pró-Opiomelanocortina , Peixe-Zebra , Animais , Pró-Opiomelanocortina/metabolismo , Pró-Opiomelanocortina/genética , Camundongos , Hipotálamo/metabolismo , Ingestão de Alimentos/genética , Ingestão de Alimentos/fisiologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Feminino , Masculino , Camundongos Transgênicos , Humanos , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Mamíferos/metabolismo , Mamíferos/genética
4.
Brief Bioinform ; 25(4)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38975894

RESUMO

Chimeric antigen receptor (CAR) therapy has emerged as a ground-breaking advancement in cancer treatment, harnessing the power of engineered human immune cells to target and eliminate cancer cells. The escalating interest and investment in CAR therapy in recent years emphasize its profound significance in clinical research, positioning it as a rapidly expanding frontier in the field of personalized cancer therapies. A crucial step in CAR therapy design is choosing the right target as it determines the therapy's effectiveness, safety and specificity against cancer cells, while sparing healthy tissues. Herein, we propose a suite of tools for the identification and analysis of potential CAR targets leveraging expression data from The Cancer Genome Atlas and Genotype-Tissue Expression Project, which are implemented in CARTAR website. These tools focus on pinpointing tumor-associated antigens, ensuring target selectivity and assessing specificity to avoid off-tumor toxicities and can be used to rationally designing dual CARs. In addition, candidate target expression can be explored in cancer cell lines using the expression data for the Cancer Cell Line Encyclopedia. To our best knowledge, CARTAR is the first website dedicated to the systematic search of suitable candidate targets for CAR therapy. CARTAR is publicly accessible at https://gmxenomica.github.io/CARTAR/.


Assuntos
Neoplasias , Receptores de Antígenos Quiméricos , Humanos , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Receptores de Antígenos Quiméricos/imunologia , Neoplasias/terapia , Neoplasias/genética , Imunoterapia Adotiva/métodos , Software , Internet , Biologia Computacional/métodos , Bases de Dados Genéticas
5.
Mol Biol Evol ; 40(7)2023 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-37247388

RESUMO

The genetic bases underlying the evolution of morphological and functional innovations of the mammalian inner ear are poorly understood. Gene regulatory regions are thought to play an important role in the evolution of form and function. To uncover crucial hearing genes whose regulatory machinery evolved specifically in mammalian lineages, we mapped accelerated noncoding elements (ANCEs) in inner ear transcription factor (TF) genes and found that PKNOX2 harbors the largest number of ANCEs within its transcriptional unit. Using reporter gene expression assays in transgenic zebrafish, we determined that four PKNOX2-ANCEs drive differential expression patterns when compared with ortholog sequences from close outgroup species. Because the functional role of PKNOX2 in cochlear hair cells has not been previously investigated, we decided to study Pknox2 null mice generated by CRISPR/Cas9 technology. We found that Pknox2-/- mice exhibit reduced distortion product otoacoustic emissions (DPOAEs) and auditory brainstem response (ABR) thresholds at high frequencies together with an increase in peak 1 amplitude, consistent with a higher number of inner hair cells (IHCs)-auditory nerve synapsis observed at the cochlear basal region. A comparative cochlear transcriptomic analysis of Pknox2-/- and Pknox2+/+ mice revealed that key auditory genes are under Pknox2 control. Hence, we report that PKNOX2 plays a critical role in cochlear sensitivity at higher frequencies and that its transcriptional regulation underwent lineage-specific evolution in mammals. Our results provide novel insights about the contribution of PKNOX2 to normal auditory function and to the evolution of high-frequency hearing in mammals.


Assuntos
Fatores de Transcrição , Peixe-Zebra , Animais , Camundongos , Cóclea/metabolismo , Audição , Mamíferos/genética , Camundongos Knockout , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
6.
Immunol Cell Biol ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38873699

RESUMO

Antibiotic resistance is a major public health threat, and alternatives to antibiotic therapy are urgently needed. Immunotherapy, particularly the blockade of inhibitory immune checkpoints, is a leading treatment option in cancer and autoimmunity. In this study, we used a murine model of Salmonella Typhimurium infection to investigate whether immune checkpoint blockade could be applied to bacterial infection. We found that the immune checkpoint T-cell immunoglobulin and ITIM domain (TIGIT) was significantly upregulated on lymphocytes during infection, particularly on CD4+ T cells, drastically limiting their proinflammatory function. Blockade of TIGIT in vivo using monoclonal antibodies was able to enhance immunity and improve bacterial clearance. The efficacy of anti-TIGIT was dependent on the capacity of the antibody to bind to Fc (fragment crystallizable) receptors, giving important insights into the mechanism of anti-TIGIT therapy. This research suggests that targeting immune checkpoints, such as TIGIT, has the potential to enhance immune responses toward bacteria and restore antibacterial treatment options in the face of antibiotic resistance.

7.
Arch Sex Behav ; 53(1): 275-292, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37679506

RESUMO

Through sexual exploration, adolescents learn that they are sexual beings with choices, desires, and are deserving of pleasure, which corresponds to sexual subjectivity. However, the two measures of this construct (i.e., Female Sexual Subjectivity Inventory and Male Sexual Subjectivity Inventory) have not been validated with younger adolescents and have different items for boys and girls (with no scale available for gender diverse individuals), limiting gender comparisons. This study examined (1) the factor structure of the adapted Short Sexual Subjectivity Inventory-11 items (SSSI-11) in a large sample of young cisgender, heterosexual and sexual and gender minority adolescents, (2) measurement invariance across language (English and French), gender, and sexual orientation, (3) validity with sexuality-related outcomes, and (4) one-year temporal stability. Results of a confirmatory factor analysis among 2001 adolescents (Mage = 15.5 years, SD = 0.60) revealed a multidimensional factor structure. The SSSI-11, in both English and French, showed adequate reliability and one-year temporal stability, and was invariant across genders, sexual orientations, and languages. Girls had lower scores on the entitlement to self-pleasure and self-efficacy in achieving pleasure factors, and higher scores on the entitlement to pleasure from a partner factor. No significant differences were observed on the basis of language or between heterosexual and sexual minority adolescents. The SSSI-11 correlated positively with sexuality-related variables. Findings support the strong psychometric properties of the SSSI-11, rendering it of considerable use in clinical, education, and research applications.


Assuntos
Heterossexualidade , Minorias Sexuais e de Gênero , Feminino , Masculino , Humanos , Adolescente , Reprodutibilidade dos Testes , Comportamento Sexual , Autoeficácia
8.
Health Expect ; 27(3): e14054, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38877659

RESUMO

INTRODUCTION: Public and patient involvement can provide crucial insights to optimise research by enhancing relevance and appropriateness of studies. The World Health Organization (WHO) engaged in an inclusive process to ensure that both technical experts and women had a voice in defining the research gaps and needs to increase or reintroduce the use of assisted vaginal birth (AVB) in settings where this intervention is needed but unavailable or underused. METHODS: We describe the methods and outcomes of online workshops led by WHO to obtain women representatives' perspectives about AVB research gaps and needs. RESULTS: After technical experts created a list of research questions based on various evidence syntheses, WHO organised four online workshops with 31 women's representatives from 27 mostly low- and middle-income (LMIC) countries. Women rated the importance and priority of the research questions proposed by the technical experts, improving and broadening some of them, added new questions, and voiced their main concerns and views about AVB. Women helped to put the research questions into context in their communities, highlighted neglected factors/dimensions that influence practices and affect women's experience during labour and childbirth, underscored less salient consequences of AVB, and highlighted the main concerns of women about research on AVB. The consolidated vision of technical experts and women's representatives resulted in a technical brief published by WHO. The technical brief is expected to stimulate global research and action closely aligned with women's priorities. CONCLUSIONS: We describe a successful experience of engaging women, mostly from LMICs, in the identification of research gaps and needs to reintroduce AVB use. This process contributed to better aligning research questions with women's views, concerns, and priorities. Given the scarcity of reports about engaging women from LMICs to optimise research, this successful experience can serve as an inspiration for future work. PATIENT OR PUBLIC CONTRIBUTION: Women representatives were involved at every stage of the workshops described in full in this manuscript.


Assuntos
Organização Mundial da Saúde , Humanos , Feminino , Gravidez , Países em Desenvolvimento , Adulto , Participação do Paciente
9.
Prep Biochem Biotechnol ; 54(4): 545-552, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37667995

RESUMO

Mushrooms are a source of primary and secondary metabolites. Little is known about the most suitable conditions for production of mushrooms by submerged fermentation. This article reports antioxidant and cytotoxic assays, in addition to quantitatively evaluating the content of proteases with fibrinolytic action in the crude extracts of two species of edible mushrooms produced in different formulations, as well as evaluating the recovery of these enzymes by aqueous two-phase systems (ATPS). The mushrooms Pleurotus ostreatus and Pleurotus eryngii, at concentration of 100 µg/mL, displayed inhibition of DPPH and ABTS radicals below 50%. In the cytotoxicity test, the cells human fibroblast cell lines (MRC-5) showed cell viability greater than 80%. Concerning fibrinolytic activity, P. eryngii presented 226.47 ± 7.26 U/mL, therefore being more efficient than P. ostreatus (71.5 ± 0.56 U/mL). In the recovery of the P. eryngii extract by ATPS, the fibrinolytic protease was partitioned in the salt phase (30.25 U/mL). The molecular mass of the proteases was between 75 and 100 kDa. These results prove the low cytotoxicity of the extracts produced and that fermentation in supplemented malt broth favored the excretion of fibrinolytic proteases compared to the other evaluated media.


Assuntos
Agaricales , Antineoplásicos , Pleurotus , Humanos , Antioxidantes/química , Pleurotus/química , Peptídeo Hidrolases/metabolismo , Agaricales/química , Endopeptidases/metabolismo , Antineoplásicos/metabolismo
10.
Anim Cogn ; 26(1): 59-72, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36542172

RESUMO

The extension of cognition beyond the brain to the body and beyond the body to the environment is an area of debate in philosophy and the cognitive sciences. Yet, these debates largely overlook olfaction, a sensory modality used by most animals. Here, I use the philosopher's framework to explore the implications of embodiment for olfactory cognition. The philosopher's 4E framework comprises embodied cognition, emerging from a nervous system characterized by its interactions with its body. The necessity of action for perception adds enacted cognition. Cognition is further embedded in the sensory inputs of the individual and is extended beyond the individual to information stored in its physical and social environments. Further, embodiment must fulfill the criterion of mutual manipulability, where an agent's cognitive state is involved in continual, reciprocal influences with its environment. Cognition cannot be understood divorced from evolutionary history, however, and I propose adding evolved, as a fifth term to the 4E framework. We must, therefore, begin at the beginning, with chemosensation, a sensory modality that underlies purposive behavior, from bacteria to humans. The PROUST hypothesis (perceiving and reconstructing odor utility in space and time) describers how olfaction, this ancient scaffold and common denominator of animal cognition, fulfills the criteria of embodied cognition. Olfactory cognition, with its near universal taxonomic distribution as well as the near absence of conscious representation in humans, may offer us the best sensorimotor system for the study of embodiment.


Assuntos
Cognição , Olfato , Humanos , Animais , Cognição/fisiologia , Encéfalo/fisiologia , Odorantes
11.
J Sex Marital Ther ; 49(5): 550-562, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36522833

RESUMO

Anxiety sensitivity, the fear of physiological arousal sensations, has been linked to lower sexual frequency, poorer sexual function, and greater sexual anxiety. The current study assessed whether anxiety sensitivity specific to the sexual context, termed sexual anxiety sensitivity, was linked to a wide range of indicators of sexual well-being over and above associations accounted for by general anxiety sensitivity. As a first step, we developed the Sexual Anxiety Sensitivity Inventory (SASI). Participants were 484 adults aged 19 to 60 years old who completed an on-line survey. To develop the SASI, we constructed parallel items to those on the Anxiety Sensitivity Scale-3 (ASI-3; Taylor et al., 2007). The SASI demonstrated the same three-factor structure as the ASI-3 and showed high internal consistency providing evidence for its reliability. As predicted, sexual anxiety sensitivity was significantly associated with all ten of the markers of the behavioral, cognitive-affective, and functional domains of sexual well-being assessed and six of these associations remained significant after controlling for general anxiety sensitivity. The results provide evidence that sexual anxiety sensitivity is an important construct for understanding individuals' sexual well-being and provide initial evidence that the specificity of the SASI has value as a reliable and valid measure for assessing sex-related anxiety sensitivity. Implications for clinicians and researchers are discussed.


Assuntos
Ansiedade , Comportamento Sexual , Adulto , Humanos , Adulto Jovem , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Psicometria , Ansiedade/psicologia , Comportamento Sexual/psicologia , Medo/psicologia
12.
J Chem Phys ; 158(20)2023 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-37226991

RESUMO

One of the most accepted hypothesis to explain the anomalous behavior of water is the presence of a critical point between two liquids, the liquid-liquid critical point (LLCP), buried within the deep supercooled regime. Unfortunately, such hypothesis is hard to be experimentally confirmed due to fast freezing. Here, we show that the TIP4P/Ice water potential shifted by 400 bar can reproduce with unprecedented accuracy the experimental isothermal compressibility of water and its liquid equation of state for a wide pressure and temperature range. We find, both by extrapolation of response function maxima and by a Maxwell construction, that the location of the model LLCP is consistent with previous calculations. According to the pressure shift needed to recover the experimental behavior of supercooled water, we estimate the experimental LLCP to be located around 1250 bar and 195 K. We use the model to estimate the ice nucleation rate (J) in the vicinity of the hypothesized LLCP experimental location and obtain J = 1024 m-3 s-1. Thereby, experiments where the ratio between the cooling rate and the sample volume is equal or larger than the estimated nucleation rate could probe liquid-liquid equilibrium before freezing. Such conditions are not accessible in common experiments with microdroplets cooled at a few kelvin per second, but they could be, for instance, using nanodroplets of around 50 nm radius observed in a millisecond timescale.

13.
An Acad Bras Cienc ; 95(suppl 1): e20220552, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37585969

RESUMO

A fibrinolytic enzyme from the microalga Dunaliella tertiolecta was produced under mixotrophic conditions using different corn steep liquor (CSL) concentrations ( 0 ≤ CLS ≤ 0.75%), purified using a combination of salting out and ion-exchange chromatography, and then biochemical characterized. Cultivation of this microalga using 0.5% CSL led to the highest maximum cell concentration (1.960±0.010 mg L-1) and cell productivity (0.140g L-1 day-1), besides a high fibrinolytic activity of the extract obtained by the homogenization method (102 ±1 U mL-1). The enzyme extracted from the microalgal biomass was 5-fold purified with a 20% yield and was found to have a specific activity of 670 U mg-1. The enzyme, whose molecular weight determined by fibrin zymography was 10 kDa, was shown to be stable at pH 3.0-9.0 and up to 70°C with optimal pH and temperature values of 8.0 and 50°C, respectively. When compared to other fibrinolytic enzymes, this protease stood out for its high fibrinolytic activity, which was enhanced by Fe2+, inhibited by Zn2+, Cu2+, Mg2+, and Ca2+, and strongly inhibited by phenylmethylsulfonyl fluoride, suggesting that it belongs to the serine metalloprotease family. Moreover, thanks to its thermal stability, the enzyme may be easily preserved and activated under high-temperature conditions.


Assuntos
Microalgas , Zea mays , Análise Custo-Benefício , Fibrina , Concentração de Íons de Hidrogênio , Temperatura
14.
Acta Oncol ; 61(1): 73-80, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34632924

RESUMO

INTRODUCTION: Radiotherapy (RT) for head and neck cancer is now guided by cone-beam computed tomography (CBCT). We aim to identify a CBCT radiomic signature predictive of progression to RT. MATERIAL AND METHODS: A cohort of 93 patients was split into training (n = 60) and testing (n = 33) sets. A total of 88 features were extracted from the gross tumor volume (GTV) on each CBCT. Receiver operating characteristic (ROC) curves were used to determine the power of each feature at each week of treatment to predict progression to radio(chemo)therapy. Only features with AUC > 0.65 at each week were pre-selected. Absolute differences were calculated between features from each weekly CBCT and baseline CBCT1 images. The smallest detectable change (C = 1.96 × SD, SD being the standard deviation of differences between feature values calculated on CBCT1 and CBCTn) with its confidence interval (95% confidence interval [CI]) was determined for each feature. The features for which the change was larger than C for at least 5% of patients were then selected. A radiomics-based model was built at the time-point that showed the highest AUC and compared with models relying on clinical variables. RESULTS: Seven features had an AUC > 0.65 at each week, and six exhibited a change larger than the predefined CI 95%. After exclusion of inter-correlated features, only one parameter remains, Coarseness. Among clinical variable, only hemoglobin value was significant. AUC for predicting the treatment response were 0.78 (p = .006), 0.85 (p < .001), and 0.99 (p < .001) for clinical, CBCT4-radiomics (Coarseness) and clinical + radiomics based models respectively. The mean AUC of this last model on a 5-fold cross-validation was 0.80 (±0.09). On the testing cohort, the best prediction was given by the combined model (balanced accuracy [BAcc] 0.67 , p < .001). CONCLUSIONS: We described a feature selection methodology for delta-radiomics that is able to select reproducible features which are informative due to their change during treatment. A selected delta radiomics feature may improve clinical-based prediction models.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Neoplasias de Cabeça e Pescoço , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Curva ROC , Planejamento da Radioterapia Assistida por Computador , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço
15.
Nature ; 540(7634): 574-578, 2016 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-27974806

RESUMO

The pressing global issue of food insecurity due to population growth, diminishing land and variable climate can only be addressed in agriculture by improving both maximum crop yield potential and resilience. Genetic modification is one potential solution, but has yet to achieve worldwide acceptance, particularly for crops such as wheat. Trehalose-6-phosphate (T6P), a central sugar signal in plants, regulates sucrose use and allocation, underpinning crop growth and development. Here we show that application of a chemical intervention strategy directly modulates T6P levels in planta. Plant-permeable analogues of T6P were designed and constructed based on a 'signalling-precursor' concept for permeability, ready uptake and sunlight-triggered release of T6P in planta. We show that chemical intervention in a potent sugar signal increases grain yield, whereas application to vegetative tissue improves recovery and resurrection from drought. This technology offers a means to combine increases in yield with crop stress resilience. Given the generality of the T6P pathway in plants and other small-molecule signals in biology, these studies suggest that suitable synthetic exogenous small-molecule signal precursors can be used to directly enhance plant performance and perhaps other organism function.

16.
Proc Natl Acad Sci U S A ; 116(12): 5405-5410, 2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30833393

RESUMO

Biomimetic systems often exhibit striking designs well adapted to specific functions that have been inspiring the development of new technologies. Herein, we explored the remarkable ability of honey bees to catch and release large quantities of pollen grains. Hair spacing and height on bees are crucial for their ability to mechanically fix pollen grains. Inspired by this, we proposed the concept of a micropatterned surface for microparticle entrapment, featuring high-aspect-ratio elastic micropillars spaced to mimic the hairy surface of bees. The hypothesis was validated by investigating the ability of polydimethylsiloxane microfabricated patches to fix microparticles. The geometrical arrangement, spacing, height, and flexibility of the fabricated micropillars, and the diameter of the microparticles, were investigated. Higher entrapment capability was found through the match between particle size and pillar spacing, being consistent with the observations that the diameter of pollen grains is similar to the spacing between hairs on bees' legs. Taller pillars permitted immobilization of higher quantities of particles, consistent with the high aspect ratio of bees' hairs. Our biomimetic surfaces were explored for their ability to fix solid microparticles for drug-release applications, using tetracycline hydrochloride as a model antibiotic. These surfaces allowed fixation of more than 20 mg/cm2 of antibiotic, about five times higher dose than commercialized patches (5.1 mg/cm2). Such bioinspired hairy surfaces could find applications in a variety of fields where dry fixation of high quantities of micrometer-sized objects are needed, including biomedicine, agriculture, biotechnology/chemical industry, and cleaning utensils.


Assuntos
Abelhas/ultraestrutura , Materiais Biomiméticos/metabolismo , Portadores de Fármacos/química , Polinização , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Portadores de Fármacos/metabolismo , Escherichia coli/efeitos dos fármacos , Pólen , Staphylococcus aureus/efeitos dos fármacos
17.
An Acad Bras Cienc ; 94(2): e20201636, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35319622

RESUMO

Hypertension is a factor that contributes to the risk of chronic diseases. The inhibition of angiotensin-I converting enzyme (ACE) is a useful therapeutic approach to the hypertension treatment. The algae have been an alternative for the production of ACE inhibitory (ACEi) peptides from enzymatic hydrolysis due to their protein-rich biomass. The aim of this study was to systematically review the literature regarding the production, composition and activity of ACEi peptides derived from algae proteins. Systematic database searches identified 648 related articles. Among these, only 14 were selected according to the eligibility criteria to this review. Macroalgae are more studied than microalgae as sources of ACEi peptides. Furthermore, hydrolysates by thermolysin or bromelain exhibited the highest ACEi activity compared to other enzymes. The main features of the peptides with high ACE inhibition are low molecular weight, short amino acids sequence and non-competitive inhibition pattern. In vivo studies using hydrolysates and peptides derived from algae proteins showed antihypertensive activity in spontaneously hypertensive rats (SHR). Thus, it is suggested that ACEi peptides derived from algae can be considered as potential antihypertensive.


Assuntos
Inibidores da Enzima Conversora de Angiotensina , Hipertensão , Inibidores da Enzima Conversora de Angiotensina/química , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Angiotensinas/uso terapêutico , Animais , Anti-Hipertensivos/química , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Peptídeos/farmacologia , Ratos
18.
An Acad Bras Cienc ; 94(suppl 3): e20211447, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36417612

RESUMO

This study aims to evaluate the in silico genomic characteristics of Streptococcus infantarius subsp. infantarius, isolated from Coalho cheese from Paraíba, Brazil, with a view to application in lactic fermentations. rRNA sequences from the 16S ribosomal region were used as input to GenBank, in the search for patterns that could reveal a non-pathogenic behavior of S. infantarius subsp. infantarius, comparing mobile genetic elements, antibiotic resistance genes, pan-genome analysis and multi-genome alignment among related species. S. infantarius subsp. infantarius CJ18 was the only complete genome reported by BLAST/NCBI with high similarity and after comparative genetics with complete genomes of Streptococcus agalactiae (SAG153, NJ1606) and Streptococcus thermophilus (ST106, CS18, IDCC2201, APC151) revealed that CJ18 showed a low number of transposases and integrases, infection by phage bacteria of the Streptococcus genus, absence of antibiotic resistance genes and presence of bacteriocin, folate and riboflavin producing genes. The genome alignment revealed that the collinear blocks of S. thermophilus ST106 and S. agalactiae SAG153 have inverted blocks when compared to the CJ18 genome due to gene positioning, insertions and deletions. Therefore, the strains of S. infantarius subsp. infantarius isolated from Coalho cheese from Paraíba showed genomic similarity with CJ18 and the mobility of genes analyzed in silico showed absence of pathogenicity throughout the genome of CJ18, indicating the potential of these strains for the dairy industry.


Assuntos
Genômica , Streptococcus , Fermentação , Streptococcus/genética , Análise de Sequência de DNA
19.
An Acad Bras Cienc ; 94(4): e20201438, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35830020

RESUMO

This work aimed to compare the production of collagenolytic proteases produced by M. subtilissimus UCP1262 in submerged fermentation (SF) and solid-state fermentation (SSF) as well as extracting in aqueous two-phase system (ATPS). Collagenolytic protease production was performed in using MS-2 culture medium (SF) and soybean bran as substrate (SSF). Subsequently, the fermented liquid from both fermentations were used for the extraction of enzyme by ATPS, it was verified the influence of different variables from a factorial design 23. In SSF the highest protease and collagenolytic activities were achieved with 362.66 U/mL and 179.81 U/mL, respectively. When compared with SF (26.33 and 18.70 U/mL) higher values were obtained in the activities. The protease partitioning from SF and SSF in ATPS showed a similar profile showing higher affinity for the polymer rich phase. The highest value for the response variable purification factor (3.49) was obtained in the system using SSF. Thus, SSF shows promise as a bioprocess for extracellular production of collagenolytic proteases, using of soybean bran as substrate had used sustainable raw material, aiming application this possible enzyme in the treatment of burns and postoperative scarring.


Assuntos
Mucor , Peptídeo Hidrolases , Fermentação , Glycine max , Temperatura
20.
BMC Biol ; 19(1): 244, 2021 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-34784928

RESUMO

BACKGROUND: Mammals possess unique hearing capacities that differ significantly from those of the rest of the amniotes. In order to gain insights into the evolution of the mammalian inner ear, we aim to identify the set of genetic changes and the evolutionary forces that underlie this process. We hypothesize that genes that impair hearing when mutated in humans or in mice (hearing loss (HL) genes) must play important roles in the development and physiology of the inner ear and may have been targets of selective forces across the evolution of mammals. Additionally, we investigated if these HL genes underwent a human-specific evolutionary process that could underlie the evolution of phenotypic traits that characterize human hearing. RESULTS: We compiled a dataset of HL genes including non-syndromic deafness genes identified by genetic screenings in humans and mice. We found that many genes including those required for the normal function of the inner ear such as LOXHD1, TMC1, OTOF, CDH23, and PCDH15 show strong signatures of positive selection. We also found numerous noncoding accelerated regions in HL genes, and among them, we identified active transcriptional enhancers through functional enhancer assays in transgenic zebrafish. CONCLUSIONS: Our results indicate that the key inner ear genes and regulatory regions underwent adaptive evolution in the basal branch of mammals and along the human-specific branch, suggesting that they could have played an important role in the functional remodeling of the cochlea. Altogether, our data suggest that morphological and functional evolution could be attained through molecular changes affecting both coding and noncoding regulatory regions.


Assuntos
Surdez , Perda Auditiva , Animais , Caderinas , Audição/genética , Mamíferos/genética , Proteínas de Membrana , Camundongos , Peixe-Zebra/genética , Proteínas de Peixe-Zebra
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