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1.
BMC Microbiol ; 24(1): 167, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38755524

RESUMO

BACKGROUND: The world faces a major infectious disease challenge. Interest in the discovery, design, or development of antimicrobial peptides (AMPs) as an alternative approach for the treatment of bacterial infections has increased. Insects are a good source of AMPs which are the main effector molecules of their innate immune system. Black Soldier Fly Larvae (BSFL) are being developed for large-scale rearing for food sustainability, waste reduction and as sustainable animal and fish feed. Bioinformatic studies have suggested that BSFL have the largest number of AMPs identified in insects. However, most AMPs identified in BSF have not yet undergone antimicrobial evaluation but are promising leads to treat critical infections. RESULTS: Jg7197.t1, Jg7902.t1 and Jg7904.t1 were expressed into the haemolymph of larvae following infection with Salmonella enterica serovar Typhimurium and were predicted to be AMPs using the computational tool ampir. The genes encoding these proteins were within 2 distinct clusters in chromosome 1 of the BSF genome. Following removal of signal peptides, predicted structures of the mature proteins were superimposed, highlighting a high degree of structural conservation. The 3 AMPs share primary sequences with proteins that contain a Kunitz-binding domain; characterised for inhibitory action against proteases, and antimicrobial activities. An in vitro antimicrobial screen indicated that heterologously expressed SUMO-Jg7197.t1 and SUMO-Jg7902.t1 did not show activity against 12 bacterial strains. While recombinant SUMO-Jg7904.t1 had antimicrobial activity against a range of Gram-negative and Gram-positive bacteria, including the serious pathogen Pseudomonas aeruginosa. CONCLUSIONS: We have cloned and purified putative AMPs from BSFL and performed initial in vitro experiments to evaluate their antimicrobial activity. In doing so, we have identified a putative novel defensin-like AMP, Jg7904.t1, encoded in a paralogous gene cluster, with antimicrobial activity against P. aeruginosa.


Assuntos
Antibacterianos , Defensinas , Dípteros , Larva , Animais , Defensinas/farmacologia , Defensinas/genética , Defensinas/química , Defensinas/isolamento & purificação , Antibacterianos/farmacologia , Antibacterianos/química , Dípteros/genética , Larva/efeitos dos fármacos , Larva/genética , Testes de Sensibilidade Microbiana , Sequência de Aminoácidos , Proteínas de Insetos/genética , Proteínas de Insetos/farmacologia , Proteínas de Insetos/química , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/genética , Peptídeos Antimicrobianos/química , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Bactérias Gram-Negativas/efeitos dos fármacos
2.
BMC Microbiol ; 24(1): 46, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38302896

RESUMO

BACKGROUND: Campylobacter jejuni and Campylobacter coli are the major causative agents of bacterial gastroenteritis worldwide and are known obligate microaerophiles. Despite being sensitive to oxygen and its reduction products, both species are readily isolated from animal food products kept under atmospheric conditions where they face high oxygen tension levels. RESULTS: In this study, Transposon Directed Insertion-site Sequencing (TraDIS) was used to investigate the ability of one C. jejuni strain and two C. coli strains to overcome oxidative stress, using H2O2 to mimic oxidative stress. Genes were identified that were required for oxidative stress resistance for each individual strain but also allowed a comparison across the three strains. Mutations in the perR and ahpC genes were found to increase Campylobacter tolerance to H2O2. The roles of these proteins in oxidative stress were previously known in C. jejuni, but this data indicates that they most likely play a similar role in C. coli. Mutation of czcD decreased Campylobacter tolerance to H2O2. The role of CzcD, which functions as a zinc exporter, has not previously been linked to oxidative stress. The TraDIS data was confirmed using defined deletions of perR and czcD in C. coli 15-537360. CONCLUSIONS: This is the first study to investigate gene fitness in both C. jejuni and C. coli under oxidative stress conditions and highlights both similar roles for certain genes for both species and highlights other genes that have a role under oxidative stress.


Assuntos
Infecções por Campylobacter , Campylobacter coli , Campylobacter jejuni , Animais , Campylobacter jejuni/genética , Campylobacter jejuni/metabolismo , Campylobacter coli/genética , Campylobacter coli/metabolismo , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Estresse Oxidativo/genética , Oxigênio/metabolismo , Infecções por Campylobacter/microbiologia
3.
Life Sci Alliance ; 7(4)2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38316462

RESUMO

Bidirectional interactions between the immune system and the gut microbiota are key contributors to various physiological functions. Immune-associated diseases such as cancer and autoimmunity, and efficacy of immunomodulatory therapies, have been linked to microbiome variation. Although COVID-19 infection has been shown to cause microbial dysbiosis, it remains understudied whether the inflammatory response associated with vaccination also impacts the microbiota. Here, we investigate the temporal impact of COVID-19 vaccination on the gut microbiome in healthy and immuno-compromised individuals; the latter included patients with primary immunodeficiency and cancer patients on immunomodulating therapies. We find that the gut microbiome remained remarkably stable post-vaccination irrespective of diverse immune status, vaccine response, and microbial composition spanned by the cohort. The stability is evident at all evaluated levels including diversity, phylum, species, and functional capacity. Our results indicate the resilience of the gut microbiome to host immune changes triggered by COVID-19 vaccination and suggest minimal, if any, impact on microbiome-mediated processes. These findings encourage vaccine acceptance, particularly when contrasted with the significant microbiome shifts observed during COVID-19 infection.


Assuntos
COVID-19 , Microbioma Gastrointestinal , Neoplasias , Humanos , Vacinas contra COVID-19 , COVID-19/prevenção & controle , Vacinação
4.
Endocrinology ; 165(3)2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38279940

RESUMO

The arcuate nucleus kisspeptin (ARNKISS) neurons represent the GnRH pulse generator that likely drives pulsatile gonadotropin secretion in all mammals. Using an improved GCaMP fiber photometry system enabling long-term continuous recordings, we aimed to establish a definitive profile of ARNKISS neuronal activity across the murine estrous cycle. As noted previously, a substantial reduction in the frequency of ARNKISS neuron synchronization events (SEs) occurs on late proestrus and extends into estrus. The SE amplitude remains constant throughout the cycle. During metestrus, we unexpectedly detected many multipeak SEs where many SEs occurred rapidly, within 160 seconds of each other. By applying a machine learning-based, k-means clustering analysis, we were further able to detect substantial within-stage variability in the patterns of pulse generator activity. Estrous cycle-dependent changes in SE activity occurred around the time of lights on and off. We also find that a mild stressor such as vaginal lavage reduces ARNKISS neuron SE frequency for up to 3 hours. These observations provide a comprehensive account of ARNKISS neuron activity across the estrous cycle, highlight a new pattern of multipeak SE activity, and introduce a new k-means clustering approach for analyzing ARNKISS neuron population behavior.


Assuntos
Hormônio Liberador de Gonadotropina , Hormônio Luteinizante , Animais , Feminino , Camundongos , Núcleo Arqueado do Hipotálamo/metabolismo , Ciclo Estral/fisiologia , Hormônio Liberador de Gonadotropina/metabolismo , Kisspeptinas/metabolismo , Neurônios/metabolismo
5.
Nature ; 625(7993): 189-194, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38057663

RESUMO

In vitro-transcribed (IVT) mRNAs are modalities that can combat human disease, exemplified by their use as vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). IVT mRNAs are transfected into target cells, where they are translated into recombinant protein, and the biological activity or immunogenicity of the encoded protein exerts an intended therapeutic effect1,2. Modified ribonucleotides are commonly incorporated into therapeutic IVT mRNAs to decrease their innate immunogenicity3-5, but their effects on mRNA translation fidelity have not been fully explored. Here we demonstrate that incorporation of N1-methylpseudouridine into mRNA results in +1 ribosomal frameshifting in vitro and that cellular immunity in mice and humans to +1 frameshifted products from BNT162b2 vaccine mRNA translation occurs after vaccination. The +1 ribosome frameshifting observed is probably a consequence of N1-methylpseudouridine-induced ribosome stalling during IVT mRNA translation, with frameshifting occurring at ribosome slippery sequences. However, we demonstrate that synonymous targeting of such slippery sequences provides an effective strategy to reduce the production of frameshifted products. Overall, these data increase our understanding of how modified ribonucleotides affect the fidelity of mRNA translation, and although there are no adverse outcomes reported from mistranslation of mRNA-based SARS-CoV-2 vaccines in humans, these data highlight potential off-target effects for future mRNA-based therapeutics and demonstrate the requirement for sequence optimization.


Assuntos
Mudança da Fase de Leitura do Gene Ribossômico , Pseudouridina , RNA Mensageiro , Animais , Humanos , Camundongos , Vacina BNT162/efeitos adversos , Vacina BNT162/genética , Vacina BNT162/imunologia , Mudança da Fase de Leitura do Gene Ribossômico/genética , RNA Mensageiro/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Pseudouridina/análogos & derivados , Pseudouridina/metabolismo , Ribossomos/metabolismo , Biossíntese de Proteínas
6.
Anim Microbiome ; 5(1): 39, 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37605221

RESUMO

Antibiotics are widely used in pig farming across the world which has led to concerns about the potential impact on human health through the selection of antibiotic resistant pathogenic bacteria. This worry has resulted in the development of a production scheme known as pigs Raised Without Antibiotics (RWA), in which pigs are produced in commercial farms, but are ear-tagged as RWA until slaughter unless they receive treatment, thus allowing the farmer to sell the pigs either as premium priced RWA or as conventional meat. Development of antibiotic resistance in pig farming has been studied in national surveys of antibiotic usage and resistance, as well as in experimental studies of groups of pigs, but not in individual pigs followed longitudinally in a commercial pig farm. In this study, a cohort of RWA designated pigs were sampled at 10 time points from birth until slaughter along with pen-mates treated with antibiotics at the same farm. From these samples, the microbiome, determined using 16S sequencing, and the resistome, as determined using qPCR for 82 resistance genes, was investigated, allowing us to examine the difference between RWA pigs and antibiotic treated pigs. We furthermore included 176 additional pigs from six different RWA farms which were sampled at the slaughterhouse as an endpoint to substantiate the cohort as well as for evaluation of intra-farm variability. The results showed a clear effect of age in both the microbiome and resistome composition from early life up until slaughter. As a function of antibiotic treatment, however, we observed a small but significant divergence between treated and untreated animals in their microbiome composition immediately following treatment, which disappeared before 8 weeks of age. The effect on the resistome was evident and an effect of treatment could still be detected at week 8. In animals sampled at the slaughterhouse, we observed no difference in the microbiome or the resistome as a result of treatment status but did see a strong effect of farm origin. Network analysis of co-occurrence of microbiome and resistome data suggested that some resistance genes may be transferred through mobile genetic elements, so we used Hi-C metagenomics on a subset of samples to investigate this. We conclude that antibiotic treatment has a differential effect on the microbiome vs. the resistome and that although resistance gene load is increased by antibiotic treatment load, this effect disappears before slaughter. More studies are needed to elucidate the optimal way to rear pigs without antibiotics.

7.
BMC Microbiol ; 23(1): 97, 2023 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-37024800

RESUMO

Campylobacter species are the major cause of bacterial gastroenteritis. As there is no effective vaccine, combined with the rapid increase in antimicrobial resistant strains, there is a need to identify new targets for intervention. Essential genes are those that are necessary for growth and/or survival, making these attractive targets. In this study, comprehensive transposon mutant libraries were created in six C. jejuni strains, four C. coli strains and one C. lari and C. hyointestinalis strain, allowing for those genes that cannot tolerate a transposon insertion being called as essential. Comparison of essential gene lists using core genome analysis can highlight those genes which are common across multiple strains and/or species. Comparison of C. jejuni and C. coli, the two species that cause the most disease, identified 316 essential genes. Genes of interest highlighted members of the purine pathway being essential for C. jejuni whilst also finding that a functional potassium uptake system is essential. Protein-protein interaction networks using these essential gene lists also highlighted proteins in the purine pathway being major 'hub' proteins which have a large number of interactors across the network. When adding in two more species (C. lari and C. hyointestinalis) the essential gene list reduces to 261. Within these 261 essential genes, there are many genes that have been found to be essential in other bacteria. These include htrB and PEB4, which have previously been found as core virulence genes across Campylobacter species in other studies. There were 21 genes which have no known function with eight of these being associated with the membrane. These surface-associated essential genes may provide attractive targets. The essential gene lists presented will help to prioritise targets for the development of novel therapeutic and preventative interventions.


Assuntos
Infecções por Campylobacter , Campylobacter coli , Campylobacter jejuni , Campylobacter , Humanos , Campylobacter jejuni/genética , Campylobacter coli/genética , Infecções por Campylobacter/microbiologia
8.
Microbiol Spectr ; : e0421322, 2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36815781

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) clonal-complex 398 (CC398) is the dominant livestock-associated (LA) MRSA lineage in European livestock and an increasing cause of difficult-to-treat human disease. LA-CC398 MRSA evolved from a diverse human-associated methicillin-sensitive population, and this transition from humans to livestock was associated with three mobile genetic elements (MGEs). In this study, we apply transposon-directed insertion site sequencing (TraDIS), a high-throughput transposon mutagenesis approach, to investigate genetic signatures that contribute to LA-CC398 causing disease in humans. We identified 26 genes associated with LA-CC398 survival in human blood and 47 genes in porcine blood. We carried out phylogenetic reconstruction on 1,180 CC398 isolates to investigate the genetic context of all identified genes. We found that all genes associated with survival in human blood were part of the CC398 core genome, while 2/47 genes essential for survival in porcine blood were located on MGEs. Gene SAPIG0966 was located on the previously identified Tn916 transposon carrying a tetracycline resistance gene, which has been shown to be stably inherited within LA-CC398. Gene SAPIG1525 was carried on a phage element, which in part, matched phiSa2wa_st1, a previously identified bacteriophage carrying the Panton-Valentine leucocidin (PVL) virulence factor. Gene deletion mutants constructed in two LA-CC398 strains confirmed that the SAPIG0966 carrying Tn916 and SAPIG1525 were important for CC398 survival in porcine blood. Our study shows that MGEs that carry antimicrobial resistance and virulence genes could have a secondary function in bacterial survival in blood and may be important for host adaptation. IMPORTANCE CC398 is the dominant type of methicillin-resistant Staphylococcus aureus (MRSA) in European livestock and a growing cause of human infections. Previous studies have suggested MRSA CC398 evolved from human-associated methicillin-sensitive Staphylococcus aureus and is capable of rapidly readapting to human hosts while maintaining antibiotic resistance. Using high-throughput transposon mutagenesis, our study identified 26 and 47 genes important for MRSA CC398 survival in human and porcine blood, respectively. Two of the genes important for MRSA CC398 survival in porcine blood were located on mobile genetic elements (MGEs) carrying resistance or virulence genes. Our study shows that these MGEs carrying antimicrobial resistance and virulence genes could have a secondary function in bacterial survival in blood and may be important for blood infection and host adaptation.

9.
PLoS Genet ; 18(3): e1009776, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35286304

RESUMO

Shotgun metagenomics is a powerful tool to identify antimicrobial resistance (AMR) genes in microbiomes but has the limitation that extrachromosomal DNA, such as plasmids, cannot be linked with the host bacterial chromosome. Here we present a comprehensive laboratory and bioinformatics pipeline HAM-ART (Hi-C Assisted Metagenomics for Antimicrobial Resistance Tracking) optimised for the generation of metagenome-assembled genomes including both chromosomal and extrachromosomal AMR genes. We demonstrate the performance of the pipeline in a study comparing 100 pig faecal microbiomes from low- and high-antimicrobial use pig farms (organic and conventional farms). We found significant differences in the distribution of AMR genes between low- and high-antimicrobial use farms including a plasmid-borne lincosamide resistance gene exclusive to high-antimicrobial use farms in three species of Lactobacilli. The bioinformatics pipeline code is available at https://github.com/lkalmar/HAM-ART.


Assuntos
Anti-Infecciosos , Microbiota , Animais , Antibacterianos , Anti-Infecciosos/farmacologia , Farmacorresistência Bacteriana/genética , Metagenômica , Suínos
10.
Int J Mol Sci ; 22(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201246

RESUMO

Disordered plant chaperones play key roles in helping plants survive in harsh conditions, and they are indispensable for seeds to remain viable. Aside from well-known and thoroughly characterized globular chaperone proteins, there are a number of intrinsically disordered proteins (IDPs) that can also serve as highly effective protecting agents in the cells. One of the largest groups of disordered chaperones is the group of dehydrins, proteins that are expressed at high levels under different abiotic stress conditions, such as drought, high temperature, or osmotic stress. Dehydrins are characterized by the presence of different conserved sequence motifs that also serve as the basis for their categorization. Despite their accepted importance, the exact role and relevance of the conserved regions have not yet been formally addressed. Here, we explored the involvement of each conserved segment in the protective function of the intrinsically disordered stress protein (IDSP) A. thaliana's Early Response to Dehydration (ERD14). We show that segments that are directly involved in partner binding, and others that are not, are equally necessary for proper function and that cellular protection emerges from the balanced interplay of different regions of ERD14.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Proteínas Intrinsicamente Desordenadas/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas Intrinsicamente Desordenadas/genética , Chaperonas Moleculares/genética , Pressão Osmótica , Proteínas de Plantas/genética
11.
Int J Mol Sci ; 22(9)2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-34063036

RESUMO

Urinary extracellular vesicles (EVs) and their RNA cargo are a novel source of biomarkers for various diseases. We aimed to identify the optimal method for isolating small (<200 nm) EVs from human urine prior to small RNA analysis. EVs from filtered healthy volunteer urine were concentrated using three methods: ultracentrifugation (UC); a precipitation-based kit (PR); and ultrafiltration (UF). EVs were further purified by size-exclusion chromatography (SEC). EV preparations were analysed with transmission electron microscopy (TEM), Western blotting, nanoparticle tracking analysis (NTA) and an Agilent Bioanalyzer Small RNA kit. UF yielded the highest number of particles both before and after SEC. Small RNA analysis from UF-concentrated urine identified two major peaks at 10-40 nucleotides (nt) and 40-80 nt. In contrast, EV preparations obtained after UC, PR or SEC combined with any concentrating method, contained predominantly 40-80 nt sized small RNA. Protein fractions from UF+SEC contained small RNA of 10-40 nt in size (consistent with miRNAs). These data indicate that most of the microRNA-sized RNAs in filtered urine are not associated with small-sized EVs, and highlights the importance of removing non-vesicular proteins and RNA from urine EV preparations prior to small RNA analysis.


Assuntos
Cromatografia em Gel , Vesículas Extracelulares/genética , MicroRNAs/urina , Sistema Livre de Células , Vesículas Extracelulares/ultraestrutura , Humanos , Ultracentrifugação , Ultrafiltração
12.
Neurobiol Dis ; 155: 105367, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33848636

RESUMO

Sleep disruption is a common invisible symptom of neurological dysfunction in Huntington's disease (HD) that takes an insidious toll on well-being of patients. Here we used electroencephalography (EEG) to examine sleep in 6 year old OVT73 transgenic sheep (Ovis aries) that we used as a presymptomatic model of HD. We hypothesized that despite the lack of overt symptoms of HD at this age, early alterations of the sleep-wake pattern and EEG powers may already be present. We recorded EEG from female transgenic and normal sheep (5/group) during two undisturbed 'baseline' nights with different lighting conditions. We then recorded continuously through a night of sleep disruption and the following 24 h (recovery day and night). On baseline nights, regardless of whether the lights were on or off, transgenic sheep spent more time awake than normal sheep particularly at the beginning of the night. Furthermore, there were significant differences between transgenic and normal sheep in both EEG power and its pattern of distribution during non-rapid eye movement (NREM) sleep. In particular, there was a significant decrease in delta (0.5-4 Hz) power across the night in transgenic compared to normal sheep, and the distributions of delta, theta and alpha oscillations that typically dominate the EEG in the first half of the night of normal sheep were skewed so they were predominant in the second, rather than the first half of the night in transgenic sheep. Interestingly, the effect of sleep disruption on normal sheep was also to skew the pattern of distribution of EEG powers so they looked more like that of transgenic sheep under baseline conditions. Thus it is possible that transgenic sheep exist in a state that resemble a chronic state of physiological sleep deprivation. During the sleep recovery period, normal sheep showed a significant 'rebound' increase in delta power with frontal dominance. A similar rebound was not seen in transgenic sheep, suggesting that their homeostatic response to sleep deprivation is abnormal. Although sleep abnormalities in early stage HD patients are subtle, with patients often unaware of their existence, they may contribute to impairment of neurological function that herald the onset of disease. A better understanding of the mechanisms underlying EEG abnormalities in early stage HD would give insight into how, and when, they progress into the sleep disorder. The transgenic sheep model is ideally positioned for studies of the earliest phase of disease when sleep abnormalities first emerge.


Assuntos
Eletroencefalografia/métodos , Doença de Huntington/genética , Doença de Huntington/fisiopatologia , Privação do Sono/genética , Privação do Sono/fisiopatologia , Fases do Sono/fisiologia , Animais , Animais Geneticamente Modificados , Modelos Animais de Doenças , Feminino , Ovinos
13.
Cells ; 9(8)2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32784707

RESUMO

Details of the functional mechanisms of intrinsically disordered proteins (IDPs) in living cells is an area not frequently investigated. Here, we dissect the molecular mechanism of action of an IDP in cells by detailed structural analyses based on an in-cell nuclear magnetic resonance experiment. We show that the ID stress protein (IDSP) A. thaliana Early Response to Dehydration (ERD14) is capable of protecting E. coli cells under heat stress. The overexpression of ERD14 increases the viability of E. coli cells from 38.9% to 73.9% following heat stress (50 °C × 15 min). We also provide evidence that the protection is mainly achieved by protecting the proteome of the cells. In-cell NMR experiments performed in E. coli cells show that the protective activity is associated with a largely disordered structural state with conserved, short sequence motifs (K- and H-segments), which transiently sample helical conformations in vitro and engage in partner binding in vivo. Other regions of the protein, such as its S segment and its regions linking and flanking the binding motifs, remain unbound and disordered in the cell. Our data suggest that the cellular function of ERD14 is compatible with its residual structural disorder in vivo.


Assuntos
Proteínas de Arabidopsis/fisiologia , Escherichia coli/fisiologia , Resposta ao Choque Térmico , Proteínas Intrinsicamente Desordenadas/fisiologia , Arabidopsis/fisiologia , Escherichia coli/genética , Viabilidade Microbiana , Microrganismos Geneticamente Modificados/fisiologia , Chaperonas Moleculares/fisiologia , Ligação Proteica , Domínios Proteicos , Proteoma/metabolismo
14.
Neurotherapeutics ; 17(3): 1075-1086, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32297185

RESUMO

Huntington's disease (HD) is characterised by progressive symptoms including cognitive deficits and sleep/wake disturbances reflected in an abnormal electroencephalography (EEG). Modafinil, a wake-promoting and cognitive-enhancing drug, has been considered as a treatment for HD. We used HD (R6/2) mice to investigate the potential for using modafinil to treat sleep-wake disturbance in HD. R6/2 mice show sleep-wake and EEG changes similar to those seen in HD patients, with increased rapid eye movement sleep (REMS), decreased wakefulness/increased non-REMS (NREMS), and pathological changes in EEG spectra, particularly an increase in gamma power. We recorded EEG from R6/2 and wild-type mice treated with modafinil acutely (with single doses between 25 and 100 mg/kg; at 12 and 16 weeks of age), or chronically (64 mg/kg modafinil/day from 6 to 15 weeks). Acutely, modafinil increased wakefulness in R6/2 mice and restored NREMS to wild-type levels at 12 weeks. It also suppressed the pathologically increased REMS. This was accompanied by decreased delta power, increased peak frequency of theta, and increased gamma power. At 16 weeks, acute modafinil also restored wakefulness and NREMS to wild-type levels. However, whilst REMS decreased, it did not return to normal levels. By contrast, in the chronic treatment group, modafinil-induced wakefulness was maintained at 15 weeks (after 9 weeks of treatment). Interestingly, chronic modafinil also caused widespread suppression of power across the EEG spectra, including a reduction in gamma that increases pathologically in R6/2 mice. The complex EEG effects of modafinil in R6/2 mice should provide a baseline for further studies to investigate the translatability of these result to clinical practice.


Assuntos
Eletroencefalografia/métodos , Doença de Huntington/tratamento farmacológico , Modafinila/administração & dosagem , Promotores da Vigília/administração & dosagem , Vigília/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Esquema de Medicação , Eletroencefalografia/efeitos dos fármacos , Doença de Huntington/genética , Doença de Huntington/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fases do Sono/efeitos dos fármacos , Fases do Sono/fisiologia , Vigília/fisiologia
15.
PLoS Genet ; 16(1): e1008527, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31999692

RESUMO

A form of hereditary cerebellar ataxia has recently been described in the Norwegian Buhund dog breed. This study aimed to identify the genetic cause of the disease. Whole-genome sequencing of two Norwegian Buhund siblings diagnosed with progressive cerebellar ataxia was carried out, and sequences compared with 405 whole genome sequences of dogs of other breeds to filter benign common variants. Nine variants predicted to be deleterious segregated among the genomes in concordance with an autosomal recessive mode of inheritance, only one of which segregated within the breed when genotyped in additional Norwegian Buhunds. In total this variant was assessed in 802 whole genome sequences, and genotyped in an additional 505 unaffected dogs (including 146 Buhunds), and only four affected Norwegian Buhunds were homozygous for the variant. The variant identified, a T to C single nucleotide polymorphism (SNP) (NC_006585.3:g.88890674T>C), is predicted to cause a tryptophan to arginine substitution in a highly conserved region of the potassium voltage-gated channel interacting protein KCNIP4. This gene has not been implicated previously in hereditary ataxia in any species. Evaluation of KCNIP4 protein expression through western blot and immunohistochemical analysis using cerebellum tissue of affected and control dogs demonstrated that the mutation causes a dramatic reduction of KCNIP4 protein expression. The expression of alternative KCNIP4 transcripts within the canine cerebellum, and regional differences in KCNIP4 protein expression, were characterised through RT-PCR and immunohistochemistry respectively. The voltage-gated potassium channel protein KCND3 has previously been implicated in spinocerebellar ataxia, and our findings suggest that the Kv4 channel complex KCNIP accessory subunits also have an essential role in voltage-gated potassium channel function in the cerebellum and should be investigated as potential candidate genes for cerebellar ataxia in future studies in other species.


Assuntos
Ataxia Cerebelar/genética , Doenças do Cão/genética , Proteínas Interatuantes com Canais de Kv/genética , Polimorfismo de Nucleotídeo Único , Animais , Ataxia Cerebelar/veterinária , Cerebelo/metabolismo , Cães , Proteínas Interatuantes com Canais de Kv/metabolismo , Mutação , Sequenciamento Completo do Genoma/veterinária
16.
Int J Mol Sci ; 20(9)2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31032817

RESUMO

(1) Background: Processivity is common among enzymes and mechanochemical motors that synthesize, degrade, modify or move along polymeric substrates, such as DNA, RNA, polysaccharides or proteins. Processive enzymes can make multiple rounds of modification without releasing the substrate/partner, making their operation extremely effective and economical. The molecular mechanism of processivity is rather well understood in cases when the enzyme structurally confines the substrate, such as the DNA replication factor PCNA, and also when ATP energy is used to confine the succession of molecular events, such as with mechanochemical motors. Processivity may also result from the kinetic bias of binding imposed by spatial confinement of two binding elements connected by an intrinsically disordered (ID) linker. (2) Method: By statistical physical modeling, we show that this arrangement results in processive systems, in which the linker ensures an optimized effective concentration around novel binding site(s), favoring rebinding over full release of the polymeric partner. (3) Results: By analyzing 12 such proteins, such as cellulase, and RNAse-H, we illustrate that in these proteins linker length and flexibility, and the kinetic parameters of binding elements, are fine-tuned for optimizing processivity. We also report a conservation of structural disorder, special amino acid composition of linkers, and the correlation of their length with step size. (4) Conclusion: These observations suggest a unique type of entropic chain function of ID proteins, that may impart functional advantages on diverse enzymes in a variety of biological contexts.


Assuntos
Enzimas/química , Enzimas/metabolismo , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Domínios e Motivos de Interação entre Proteínas , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Celulase/química , Celulase/metabolismo , Fenômenos Químicos , Sequência Conservada , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Relação Estrutura-Atividade
17.
J Antimicrob Chemother ; 74(5): 1182-1191, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30759229

RESUMO

OBJECTIVES: High-level ß-lactam resistance in MRSA is mediated in the majority of strains by a mecA or mecC gene. In this study, we identified 10 mec gene-negative MRSA human isolates from Austria and 11 bovine isolates from the UK showing high levels of ß-lactam resistance and sought to understand the molecular basis of the resistance observed. METHODS: Different antimicrobial resistance testing methods (disc diffusion, Etest and VITEK® 2) were used to establish the ß-lactam resistance profiles for the isolates and the isolates were further investigated by WGS. RESULTS: A number of mutations (including novel ones) in PBPs, AcrB, YjbH and the pbp4 promoter were identified in the resistant isolates, but not in closely related susceptible isolates. Importantly, a truncation in the cyclic diadenosine monophosphate phosphodiesterase enzyme, GdpP, was identified in 7 of the 10 Austrian isolates and 10 of the 11 UK isolates. Complementation of four representative isolates with an intact copy of the gdpP gene restored susceptibility to penicillins and abolished the growth defects caused by the truncation. CONCLUSIONS: This study reports naturally occurring inactivation of GdpP protein in Staphylococcus aureus of both human origin and animal origin, and demonstrates clinical relevance to a previously reported association between this truncation and increased ß-lactam resistance and impaired bacterial growth in laboratory-generated mutants. It also highlights possible limitations of genomic determination of antibiotic susceptibility based on single gene presence or absence when choosing the appropriate antimicrobial treatment for patients.


Assuntos
Doenças dos Bovinos/microbiologia , Diester Fosfórico Hidrolases/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Resistência beta-Lactâmica , beta-Lactamas/farmacologia , Alelos , Substituição de Aminoácidos , Animais , Bovinos , Genoma Bacteriano , Genômica , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Fenótipo , Diester Fosfórico Hidrolases/metabolismo , Deleção de Sequência , Staphylococcus aureus/isolamento & purificação
18.
Front Behav Neurosci ; 13: 284, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32038187

RESUMO

Previous studies suggested that both maladaptive stress response and circadian dysregulation might have a role in the background of migraine. However, effects of circadian genes on migraine have not been tested yet. In the present study, we investigated the main effect of rs10462028 of the circadian locomotor output cycles kaput (CLOCK) gene and its interaction with different stress factors on migraine. In our cross-sectional study 2,157 subjects recruited from Manchester and Budapest completed the ID-Migraine questionnaire to detect migraine type headaches (migraineID). Additional stress factors were assessed by a shortened version of the Childhood Trauma Questionnaire, the List of Threatening Experiences questionnaire, and a validated questionnaire to identify financial difficulties. Rs10462028 showed no main genetic effect on migraineID. However, chronic stress indexed by financial difficulties showed a significant interaction effect with rs10462028 (p = 0.006 in recessive model) on migraineID. This result remained significant after correction for lifetime bipolar and unipolar depression and was replicated in both subsamples, although only a trend effect was reached after Bonferroni-correction, which is the strictest correction not considering interdependences. Childhood adversity (CHA) and Recent negative life events (RLE) showed no significant gene × stress interaction with rs10462028. In addition, in silico analysis demonstrated that the genetic region tagged by rs10462028 alters the binding of several miRNAs. Our exploratory study suggests that variations in the CLOCK gene, with moderating effect on gene function through miRNA binding, in interaction with financial difficulties might influence the risk of migraine-type headaches. Thus, financial hardship as a chronic stress factor may affect migraine through altering circadian rhythms.

19.
Vet Surg ; 48(1): 79-87, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30303538

RESUMO

OBJECTIVE: To evaluate the effectiveness of laser-assisted turbinectomy (LATE) in treating brachycephalic obstructive airway syndrome (BOAS) and to investigate the potential indications. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Client-owned pugs, French bulldogs, and English bulldogs (n = 57). METHODS: A BOAS index was obtained from whole-body barometric plethysmography before BOAS conventional multilevel surgery (CMS) and 2-6 months post-CMS. Dogs with BOAS index >50% and BOAS functional grades II-III after CMS were considered candidates for LATE. A BOAS index was repeated 2-6 months after LATE. Intranasal lesions and a measurement of soft tissue proportion at the rostral entrance of choanae (STC) were recorded on the basis of computed tomography images. Logistic regressions were used to assess the intranasal predictors for being LATE candidates. RESULTS: Twenty-nine of 57 dogs were candidates for LATE, all of which were pugs or French bulldogs. The median BOAS index of dogs that were operated on (20/29 candidates) decreased from 67% post-CMS to 42% after LATE (P < .001). Soft tissue proportion at the rostral entrance of choanae was the only predictor for candidacy for LATE. Pugs (P = .021; cutoff = 64%) and French bulldogs (P = .008; cutoff = 55%) with higher STC were more likely to be candidates for LATE. After LATE, 12 of 20 dogs had temporary episodes of reverse sneezing, and nasal noise was noted in 8 of 20 dogs when sniffing and excited. CONCLUSION: Laser-assisted turbinectomy was an effective treatment for dogs with intranasal abnormalities and a poor response to CMS. Soft tissue proportion at the rostral entrance of choanae was a predictor of candidacy for LATE in pugs and French bulldogs. CLINICAL SIGNIFICANCE: Computed tomography-based measurement of STC can be used to predict whether LATE is required in addition to CMS in pugs and French bulldogs with BOAS.


Assuntos
Obstrução das Vias Respiratórias/veterinária , Doenças do Cão/terapia , Terapia a Laser/veterinária , Obstrução das Vias Respiratórias/terapia , Animais , Cães , Feminino , Terapia a Laser/métodos , Masculino , Estudos Prospectivos , Especificidade da Espécie , Resultado do Tratamento
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