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1.
J Virol ; 97(1): e0177322, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36475764

RESUMO

Flaviviruses have a cytoplasmic replicative cycle, and crucial events, such as genome translation and replication, occur in the endoplasmic reticulum. However, some viral proteins, such as C, NS1, and NS5 from Zika virus (ZIKV) containing nuclear localization signals (NLSs) and nuclear export signals (NESs), are also located in the nucleus of Vero cells. The NS2A, NS3, and NS4A proteins from dengue virus (DENV) have also been reported to be in the nucleus of A549 cells, and our group recently reported that the NS3 protein is also located in the nucleus of Huh7 and C636 cells during DENV infection. However, the NS3 protease-helicase from ZIKV locates in the perinuclear region of infected cells and alters the morphology of the nuclear lamina, a component of the nuclear envelope. Furthermore, ZIKV NS3 has been reported to accumulate on the concave face of altered kidney-shaped nuclei and may be responsible for modifying other elements of the nuclear envelope. However, nuclear localization of NS3 from ZIKV has not been substantially investigated in human host cells. Our group has recently reported that DENV and ZIKV NS3 alter the nuclear pore complex (NPC) by cleaving some nucleoporins. Here, we demonstrate the presence of ZIKV NS3 in the nucleus of Huh7 cells early in infection and in the cytoplasm at later times postinfection. In addition, we found that ZIKV NS3 contains an NLS and a putative NES and uses the classic import (importin-α/ß) and export pathway via CRM-1 to be transported between the cytoplasm and the nucleus. IMPORTANCE Flaviviruses have a cytoplasmic replication cycle, but recent evidence indicates that nuclear elements play a role in their viral replication. Viral proteins, such as NS5 and C, are imported into the nucleus, and blocking their import prevents replication. Because of the importance of the nucleus in viral replication and the role of NS3 in the modification of nuclear components, we investigated whether NS3 can be localized in the nucleus during ZIKV infection. We found that NS3 is imported into the nucleus via the importin pathway and exported to the cytoplasm via CRM-1. The significance of viral protein nuclear import and export and its relationship with infection establishment is highlighted, emphasizing the development of new host-directed antiviral therapeutic strategies.


Assuntos
Transporte Ativo do Núcleo Celular , Carioferinas , Proteínas não Estruturais Virais , Zika virus , Animais , Humanos , alfa Carioferinas/metabolismo , beta Carioferinas/metabolismo , Chlorocebus aethiops , Carioferinas/metabolismo , Sinais de Localização Nuclear/metabolismo , Células Vero , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Zika virus/genética , Infecção por Zika virus , Vírus da Dengue
2.
J Transl Med ; 22(1): 28, 2024 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-38184580

RESUMO

BACKGROUND: Electrical activity has a crucial impact on the development and survival of neurons. Numerous recent studies have shown that noninvasive electrical stimulation (NES) has neuroprotective action in various retinal disorders. OBJECTIVE: To systematically review the literature on in vivo studies and provide a comprehensive summary of the neuroprotective action and the mechanisms of NES on retinal disorders. METHODS: Based on the PRISMA guideline, a systematic review was conducted in PubMed, Web of Science, Embase, Scopus and Cochrane Library to collect all relevant in vivo studies on "the role of NES on retinal diseases" published up until September 2023. Possible biases were identified with the adopted SYRCLE's tool. RESULTS: Of the 791 initially gathered studies, 21 articles met inclusion/exclusion criteria for full-text review. The results revealed the neuroprotective effect of NES (involved whole-eye, transcorneal, transscleral, transpalpebral, transorbital electrical stimulation) on different retinal diseases, including retinitis pigmentosa, retinal degeneration, high-intraocular pressure injury, traumatic optic neuropathy, nonarteritic ischemic optic neuropathy. NES could effectively delay degeneration and apoptosis of retinal neurons, preserve retinal structure and visual function with high security, and its mechanism of action might be related to promoting the secretion of neurotrophins and growth factors, decreasing inflammation, inhibiting apoptosis. The quality scores of included studies ranged from 5 to 8 points (a total of 10 points), according to SYRCLE's risk of bias tool. CONCLUSION: This systematic review indicated that NES exerts neuroprotective effects on retinal disease models mainly through its neurotrophic, anti-inflammatory, and anti-apoptotic capabilities. To assess the efficacy of NES in a therapeutic setting, however, well-designed clinical trials are required in the future.


Assuntos
Estimulação Elétrica , Doenças Retinianas , Humanos , Projetos de Pesquisa , Retina , Degeneração Retiniana , Doenças Retinianas/terapia
3.
BMC Gastroenterol ; 24(1): 169, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760691

RESUMO

BACKGROUND: Night eating syndrome (NES) is a kind of eating disorder. NES association with gastroesophageal reflux disease (GERD) symptoms among university students is still not fully understood. We aimed to determine the relationship between NES and the presence of GERD symptoms among university students at An-Najah National University in Palestine. METHODS: This study involved undergraduate students from An-Najah National University. The data were collected through online surveys from November to December 2023. The sampling frame involved voluntary sampling, as the data were collected using a structured questionnaire to collect data on sociodemographic variables, medical history, lifestyle habits, nutritional status, GERD risk, and NES. The GERD questionnaire (GerdQ) was used to assess symptoms, while the Arabic version of the validated Night Eating Questionnaire (NEQ) was used to assess night eating. Physical activity was assessed using the short form of the International Physical Activity Questionnaire (SF-IPAQ), and adherence to a Mediterranean diet was assessed using the validated Arabic version of the MEDAS. Both univariate and multivariate analyses were also conducted to assess the study hypotheses. RESULTS: The study involved 554 participants, 59.9% female. A total of 33.4% reported GERD symptoms, with 10.3% having NES. A strong association was observed between GERD and NES and between GERD and physical activity. Night eating syndrome (AOR = 2.84, CI = 1.07-3.19), high physical activity (AOR = 0.473, CI = 1.05-3.19), and non-smoking (AOR = 0.586, CI = 1.27-7.89) were identified as independent predictors of GERD symptoms. CONCLUSION: This study revealed that 33.4% of undergraduate students were at risk of GERD, with night eaters having a greater risk. GERD risk was negatively associated with physical activity level and smoking status. No associations were found between GERD risk and weight status, Mediterranean diet adherence, sociodemographic factors, or sleep disturbances.


Assuntos
Exercício Físico , Refluxo Gastroesofágico , Síndrome do Comer Noturno , Estudantes , Humanos , Refluxo Gastroesofágico/epidemiologia , Feminino , Masculino , Estudos Transversais , Estudantes/estatística & dados numéricos , Universidades , Adulto Jovem , Síndrome do Comer Noturno/epidemiologia , Inquéritos e Questionários , Adulto , Dieta Mediterrânea/estatística & dados numéricos , Adolescente , Fatores de Risco , Estilo de Vida , Oriente Médio/epidemiologia
4.
Anal Bioanal Chem ; 416(24): 5377-5386, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39172237

RESUMO

Manganese ion homeostasis is vital for bacteria and is achieved via manganese-dependent transcription factors. Manganese mediation of transcription factor attachment to the corresponding oligonucleotide sequences can be investigated, e.g. via electrophoretic mobility shift assays (EMSA). Formation of specific biocomplexes leads to differences in the migration pattern upon gel electrophoresis. Focusing on electrophoresis in the gas-phase, applying a nano electrospray gas-phase electrophoretic mobility molecular analyzer (nES GEMMA) also known as nES differential mobility analyzer (nES DMA), and on transcription factors (MntR proteins) from Bacillus subtilis and Mycobacterium tuberculosis, we took interest in the gas-phase electrophoresis of the corresponding biospecific complexes. We compared nES GEMMA, separating analytes in the nanometer regime (a few to several hundred nm in diameter) in the gas-phase in their native state according to particle size, to EMSA data. Indeed we were able to demonstrate manganese-mediated attachment of MntR to target genomic sequences with both analytical techniques. Despite some inherent pitfalls of the nES GEMMA method like analyte/instrument surface interactions, we were able to detect the target complexes. Moreover, we were able to calculate the molecular weight (MW) of the obtained species by application of a correlation function based on nES GEMMA obtained data. As gas-phase electrophoresis also offers the possibility of offline hyphenation to orthogonal analysis techniques, we are confident that nES GEMMA measurements are not just complementary to EMSA, but will offer the possibility of further in-depth characterization of biocomplexes in the future.


Assuntos
Bacillus subtilis , Manganês , Fatores de Transcrição , Manganês/metabolismo , Manganês/química , Bacillus subtilis/metabolismo , Fatores de Transcrição/metabolismo , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Proteínas de Bactérias/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética/métodos , DNA/química , Gases/química , Eletroforese/métodos
5.
J Virol ; 96(3): e0083821, 2022 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-34787461

RESUMO

Over the past decades, studies on the biology of human adenoviruses (HAdVs) mainly focused on the HAdV prototype species C type 5 (HAdV-C5) and revealed fundamental molecular insights into mechanisms of viral replication and viral cell transformation. Recently, other HAdV species are gaining more and more attention in the field. Reports on large E1B proteins (E1B-55K) from different HAdV species showed that these multifactorial proteins possess strikingly different features along with highly conserved functions. In this work, we identified potential SUMO-conjugation motifs (SCMs) in E1B-55K proteins from HAdV species A to F. Mutational inactivation of these SCMs demonstrated that HAdV E1B-55K proteins are SUMOylated at a single lysine residue that is highly conserved among HAdV species B to E. Moreover, we provide evidence that E1B-55K SUMOylation is a potent regulator of intracellular localization and p53-mediated transcription in most HAdV species. We also identified a lysine residue at position 101 (K101), which is unique to HAdV-C5 E1B-55K and specifically regulates its SUMOylation and nucleo-cytoplasmic shuttling. Our findings reveal important new aspects on HAdV E1B-55K proteins and suggest that different E1B-55K species possess conserved SCMs while their SUMOylation has divergent cellular effects during infection. IMPORTANCE E1B-55K is a multifunctional adenoviral protein and its functions are highly regulated by SUMOylation. Although functional consequences of SUMOylated HAdV-C5 E1B-55K are well studied, we lack information on the effects of SUMOylation on homologous E1B-55K proteins from other HAdV species. Here, we show that SUMOylation is a conserved posttranslational modification in most of the E1B-55K proteins, similar to what we know about HAdV-C5 E1B-55K. Moreover, we identify subcellular localization and regulation of p53-dependent transcription as highly conserved SUMOylation-regulated E1B-55K functions. Thus, our results highlight how HAdV proteins might have evolved in different HAdV species with conserved domains involved in virus replication and differing alternative functions and interactions with the host cell machinery. Future research will link these differences and similarities to the diverse pathogenicity and organ tropism of the different HAdV species.


Assuntos
Proteínas E1B de Adenovirus/metabolismo , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/fisiologia , Interações Hospedeiro-Patógeno , Proteínas E1B de Adenovirus/química , Infecções por Adenovirus Humanos/metabolismo , Sequência de Aminoácidos , Sequência Conservada , Humanos , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Transporte Proteico , Proteína SUMO-1/metabolismo , Especificidade da Espécie , Sumoilação , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
6.
Eat Weight Disord ; 28(1): 3, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36752994

RESUMO

PURPOSE: The purpose of the current study was to examine differences in binge eating and food addiction symptoms between Night Eating Syndrome (NES) latent subtypes: evening hyperphagia with nocturnal ingestions (EHNI), evening hyperphagia-only (EHO), and nocturnal ingestions-only (NIO). It was hypothesized that the EHNI group would report more binge eating behaviors and more food addiction symptoms than both the EHO and NIO groups. Further, it was hypothesized that the EHO and NIO groups would differ with the EHO group reporting more binge eating behaviors and the NIO group reporting more food addiction symptoms. METHODS: Participants completed measures online relating to night eating, binge eating, and food addiction. Average age of the final sample was 34.3 (SD = 10.5) and 62.0% were men. Responses to the Night Eating Questionnaire (NEQ; Allison et al., 2008) were used to create an EHNI group (n = 65), an EHO group (n = 32), and a NIO group (n = 69). ANOVAs were conducted to examine between-group differences on disordered eating symptoms. RESULTS: Participants in the EHNI group reported more severe binge eating and food addiction symptoms than those in the EHO and NIO groups. However, there were no significant differences in binge eating or food addiction between the EHO and NIO groups. CONCLUSION: Individuals who meet both NES core criteria (evening hyperphagia and nocturnal ingestions) are likely at a higher risk for experiencing other, more severe disordered eating pathologies. Implications concerning assessment and future research on NES typology are discussed. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study.


Assuntos
Transtorno da Compulsão Alimentar , Bulimia , Transtornos da Alimentação e da Ingestão de Alimentos , Dependência de Alimentos , Síndrome do Comer Noturno , Masculino , Humanos , Feminino , Comportamento Alimentar , Estudos Transversais , Hiperfagia
7.
Paediatr Child Health ; 28(5): 307-323, 2023 Aug.
Artigo em Inglês, Inglês | MEDLINE | ID: mdl-37484035

RESUMO

Le risque que des infections maternelles ne soient ni décelées ni traitées augmente lorsque les soins prénatals sont inappropriés, ce qui met la santé de la mère et de son nouveau-né à risque. Lorsqu'une femme enceinte se présente tardivement pour recevoir des soins, les tests systématiques qui influent sur la prise en charge du nouveau-né devraient inclure l'antigène de surface de l'hépatite B (AgHBs), la sérologie du virus de l'hépatite C (VHC), du virus de l'immunodéficience humaine (VIH) et de la syphilis, de même que le dépistage de la Chlamydia trachomatis et de la Neisseria gonorrhoeae. Si la mère ne s'est pas soumise aux dépistages avant ou après l'accouchement et qu'elle n'est pas disponible pour s'y soumettre, il faudrait procéder au dépistage du VIH, du virus de l'hépatite B (VHB), du VHC et de la syphilis chez le nouveau-né. Le dépistage de la C. trachomatis et de la N. gonorrhoeae est toutefois réservé aux cas où le nouveau-né démontre des manifestations cliniques compatibles avec ces infections. Il est optimal d'obtenir rapidement les résultats du dépistage du VIH, du VHB et de la syphilis, car l'utilisation des traitements préventifs est circonscrite dans le temps. Il existe des interventions préventives précoces et efficaces pour les nouveau-nés à risque de VIH, de VHB, de syphilis ou de gonorrhée. Un suivi clinique étroit et des tests de suivi s'imposent auprès des nouveau-nés de mères dont les soins prénatals étaient inappropriés, car il est impossible d'exclure pleinement toutes les infections pendant la période périnatale.

8.
Can J Physiol Pharmacol ; 100(12): 1106-1114, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36223651

RESUMO

In this study, we wanted to verify whether the effect of insulin on calcium homeostasis depends on the heart's development stage. Using a quantitative 3D confocal microscopy, we tested the effect of a high insulin concentration (100 µU) in freshly cultured ventricular cardiomyocytes from newborn and adult rats. Our results showed that the cytosolic basal level of calcium was higher in newborn cardiomyocytes with no change in the nuclear basal calcium level compared with the adult cardiomyocytes; in addition, insulin induced a slow increase of cytosolic and nuclear calcium in newborn ventricular cardiomyocytes, followed by two phases. However, the first phase of slow cytosolic and nuclear calcium increase was absent in adult rat ventricular cardiomyocytes. Furthermore, the time to the onset of increase of cytosolic and nuclear calcium was longer in newborn cardiomyocytes compared with adults. Moreover, the time to peak of the calcium transient was shorter in newborns than in adult cardiomyocytes. These results demonstrate that insulin differently regulates calcium homeostasis in newborns than in adult cardiomyocytes. Thus, newborn rat cardiomyocytes, commonly used in research as a model for adult cardiomyocytes, should be used with caution when dealing with insulin in normal and disease conditions.


Assuntos
Cálcio , Miócitos Cardíacos , Ratos , Animais , Cálcio/farmacologia , Insulina/farmacologia , Células Cultivadas , Ventrículos do Coração
9.
Int J Mol Sci ; 23(22)2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36430578

RESUMO

Appropriate nucleo-cytoplasmic partitioning of proteins is a vital regulatory mechanism in phytohormone signaling and plant development. However, how this is achieved remains incompletely understood. The Karyopherin (KAP) superfamily is critical for separating the biological processes in the nucleus from those in the cytoplasm. The KAP superfamily is divided into Importin α (IMPα) and Importin ß (IMPß) families and includes the core components in mediating nucleocytoplasmic transport. Recent reports suggest the KAPs play crucial regulatory roles in Arabidopsis development and stress response by regulating the nucleo-cytoplasmic transport of members in hormone signaling. However, the KAP members and their associated molecular mechanisms are still poorly understood in maize. Therefore, we first identified seven IMPα and twenty-seven IMPß genes in the maize genome and described their evolution traits and the recognition rules for substrates with nuclear localization signals (NLSs) or nuclear export signals (NESs) in plants. Next, we searched for the protein interaction partners of the ZmKAPs and selected the ones with Arabidopsis orthologs functioning in auxin biosynthesis, transport, and signaling to predict their potential function. Finally, we found that several ZmKAPs share similar expression patterns with their interacting proteins, implying their function in root development. Overall, this article focuses on the Karyopherin superfamily in maize and starts with this entry point by systematically comprehending the KAP-mediated nucleo-cytoplasmic transport process in plants, and then predicts the function of the ZmKAPs during maize development, with a perspective on a closely associated regulatory mechanism between the nucleo-cytoplasmic transport and the phytohormone network.


Assuntos
Carioferinas , Desenvolvimento Vegetal , Humanos , alfa Carioferinas/genética , beta Carioferinas/metabolismo , Carioferinas/genética , Desenvolvimento Vegetal/genética , Reguladores de Crescimento de Plantas , Zea mays/genética , Zea mays/metabolismo
10.
Int J Mol Sci ; 23(19)2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36232866

RESUMO

The human microbiome is a vast collection of microbial species that exist throughout the human body and regulate various bodily functions and phenomena. Of the microbial species that exist in the human microbiome, those within the archaea domain have not been characterized to the extent of those in more common domains, despite their potential for unique metabolic interaction with host cells. Research has correlated tumoral presence of bacterial microbial species to the development and progression of lung cancer; however, the impacts and influences of archaea in the microbiome remain heavily unexplored. Within the United States lung cancer remains highly fatal, responsible for over 100,000 deaths every year with a 5-year survival rate of roughly 22.9%. This project attempts to investigate specific archaeal species' correlation to lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) incidence, patient staging, death rates across individuals of varying ages, races, genders, and smoking-statuses, and potential molecular targets associated with archaea microbiome. Archaeal species abundance was assessed across lung tissue samples of 527 LUAD patients, 479 LUSC patients, and 99 healthy individuals. Nine archaeal species were found to be of significantly altered abundance in cancerous samples as compared to normal counterparts, 6 of which are common to both LUAD and LUSC subgroups. Several of these species are of the taxonomic class Thermoprotei or the phylum Euryarchaeota, both known to contain metabolic processes distinct from most bacterial species. Host-microbe metabolic interactions may be responsible for the observed correlation of these species' abundance with cancer incidence. Significant microbes were correlated to patient gene expression to reveal genes of altered abundance with respect to high and low archaeal presence. With these genes, cellular oncogenic signaling pathways were analyzed for enrichment across cancer and normal samples. In comparing gene expression between LUAD and adjacent normal samples, 2 gene sets were found to be significantly enriched in cancers. In LUSC comparison, 6 sets were significantly enriched in cancer, and 34 were enriched in normals. Microbial counts across healthy and cancerous patients were then used to develop a machine-learning based predictive algorithm, capable of distinguishing lung cancer patients from healthy normal with 99% accuracy.


Assuntos
Adenocarcinoma de Pulmão , Carcinoma Pulmonar de Células não Pequenas , Carcinoma de Células Escamosas , Neoplasias Pulmonares , Microbiota , Adenocarcinoma de Pulmão/patologia , Archaea/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Microbiota/genética
11.
Rev Med Liege ; 77(3): 139-145, 2022 Mar.
Artigo em Francês | MEDLINE | ID: mdl-35258861

RESUMO

Malignant bone tumours in children are rare diseases whose survival rate has progressively improved in recent years thanks to advances in pharmacology, surgery and radiotherapy. We present the particular case of a very young child with Ewing's sarcoma of the thigh. We discuss the influence of this young age on short and long term care. Limb skeletal immaturity and the residual growth potential need to be integrated to define the safest oncological and functional strategy. For this purpose, we summarize the different possible reconstructive options. We describe the Van Nes rotationplasty that was proposed in our patient's case and we will detail the issues in terms of functional well-being and self-image.


Les tumeurs malignes osseuses de l'enfant sont des pathologies rares dont la survie s'est progressivement améliorée au cours des dernières années grâce aux progrès médicamenteux, chirurgicaux et radiothérapeutiques. Nous présentons le cas particulier d'une très jeune enfant atteinte d'un sarcome d'Ewing de la cuisse. Nous discutons de l'influence de ce jeune âge sur la prise en charge à court et à long termes. L'immaturité squelettique et le potentiel de croissance résiduelle des membres doivent être intégrés pour définir l'attitude la plus sûre sur le plan oncologique et la plus fonctionnelle. à cette fin, nous résumons les différentes options reconstructives possibles. Nous décrivons la plastie de rotation de Van Nes qui a été proposée à notre patiente et nous détaillerons les enjeux relatifs au bien-être fonctionnel et à l'image de soi.


Assuntos
Neoplasias Ósseas , Procedimentos de Cirurgia Plástica , Sarcoma de Ewing , Neoplasias Ósseas/cirurgia , Criança , Humanos , Sarcoma de Ewing/cirurgia , Taxa de Sobrevida
12.
Paediatr Child Health ; 27(1): 63-64, 2022 Mar.
Artigo em Inglês, Inglês | MEDLINE | ID: mdl-35273673

RESUMO

La prise en charge de la persistance du canal artériel est l'un des aspects les plus litigieux des soins aux nouveau-nés prématurés. On peut la classer en deux grandes catégories : la prophylaxie et le traitement en cas de symptômes. L'administration prophylactique d'indométacine par voie intraveineuse chez les nouveau-nés d'extrême petit poids à la naissance peut limiter les graves hémorragies intraventriculaires. L'échocardiographie est systématiquement recommandée pour confirmer une persistance du canal artériel avant d'envisager le traitement en cas de symptômes, qui peut prendre la forme d'un traitement conservateur, d'une pharmacothérapie ou d'une fermeture invasive. L'ibuprofène doit être considéré comme le traitement pharmacologique de première intention dans cette situation. Une forte dose peut être à privilégier, particulièrement chez les nouveau-nés prématurés de plus de trois à cinq jours de vie. Si deux traitements pharmacologiques consécutifs échouent ou si la pharmacothérapie est contre-indiquée, on peut envisager une fermeture invasive en cas de symptômes marqués lorsque l'échocardiographie révèle des signes de shunt à fort volume à travers le canal artériel et de circulation pulmonaire excessive.

13.
J Biol Chem ; 295(5): 1300-1314, 2020 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-31871052

RESUMO

ß1-chimaerin belongs to the chimaerin family of GTPase-activating proteins (GAPs) and is encoded by the CHN2 gene, which also encodes the ß2- and ß3-chimaerin isoforms. All chimaerin isoforms have a C1 domain that binds diacylglycerol as well as tumor-promoting phorbol esters and a catalytic GAP domain that inactivates the small GTPase Rac. Nuclear Rac has emerged as a key regulator of various cell functions, including cell division, and has a pathological role by promoting tumorigenesis and metastasis. However, how nuclear Rac is regulated has not been fully addressed. Here, using several approaches, including siRNA-mediated gene silencing, confocal microscopy, and subcellular fractionation, we identified a nuclear variant of ß1-chimaerin, ß1-Δ7p-chimaerin, that participates in the regulation of nuclear Rac1. We show that ß1-Δ7p-chimaerin is a truncated variant generated by alternative splicing at a cryptic splice site in exon 7. We found that, unlike other chimaerin isoforms, ß1-Δ7p-chimaerin lacks a functional C1 domain and is not regulated by diacylglycerol. We found that ß1-Δ7p-chimaerin localizes to the nucleus via a nuclear localization signal in its N terminus. We also identified a key nuclear export signal in ß1-chimaerin that is absent in ß1-Δ7p-chimaerin, causing nuclear retention of this truncated variant. Functionally analyses revealed that ß1-Δ7p-chimaerin inactivates nuclear Rac and negatively regulates the cell cycle. Our results provide important insights into the diversity of chimaerin Rac-GAP regulation and function and highlight a potential mechanism of nuclear Rac inactivation that may play significant roles in pathologies such as cancer.


Assuntos
Núcleo Celular/metabolismo , Proteínas Quimerinas/genética , Proteínas Quimerinas/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Processamento Alternativo , Motivos de Aminoácidos/genética , Animais , Células COS , Ciclo Celular/genética , Linhagem Celular Tumoral , Chlorocebus aethiops , Diglicerídeos/metabolismo , Éxons/genética , Inativação Gênica , Humanos , Domínios Proteicos/genética , Isoformas de Proteínas/metabolismo , RNA Interferente Pequeno , Deleção de Sequência , Proteínas rac1 de Ligação ao GTP/genética
14.
J Biol Chem ; 295(19): 6447-6456, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32217692

RESUMO

Interferon-regulated myxovirus resistance protein B (MxB) is an interferon-induced GTPase belonging to the dynamin superfamily. It inhibits infection with a wide range of different viruses, including HIV-1, by impairing viral DNA entry into the nucleus. Unlike the related antiviral GTPase MxA, MxB possesses an N-terminal region that contains a nuclear localization signal and is crucial for inhibiting HIV-1. Because MxB previously has been shown to reside in both the nuclear envelope and the cytoplasm, here we used bioinformatics and biochemical approaches to identify a nuclear export signal (NES) responsible for MxB's cytoplasmic location. Using the online computational tool LocNES (Locating Nuclear Export Signals or NESs), we identified five putative NES candidates in MxB and investigated whether their deletion caused nuclear localization of MxB. Our results revealed that none of the five deletion variants relocates to the nucleus, suggesting that these five predicted NES sequences do not confer NES activity. Interestingly, deletion of one sequence, encompassing amino acids 505-527, abrogated the anti-HIV-1 activity of MxB. Further mutation experiments disclosed that amino acids 515-519, and Pro-515 in particular, regulate MxB oligomerization and its binding to HIV-1 capsid, thereby playing an important role in MxB-mediated restriction of HIV-1 infection. In summary, our results indicate that none of the five predicted NES sequences in MxB appears to be required for its nuclear export. Our findings also reveal several residues in MxB, including Pro-515, critical for its oligomerization and anti-HIV-1 function.


Assuntos
Capsídeo/metabolismo , Núcleo Celular/metabolismo , Infecções por HIV/metabolismo , HIV-1/metabolismo , Proteínas de Resistência a Myxovirus/metabolismo , Multimerização Proteica , Transporte Ativo do Núcleo Celular , Núcleo Celular/genética , Núcleo Celular/virologia , Células HEK293 , Infecções por HIV/genética , HIV-1/genética , Células HeLa , Humanos , Proteínas de Resistência a Myxovirus/genética , Sinais de Exportação Nuclear , Prolina , Ligação Proteica
15.
Electrophoresis ; 42(11): 1202-1208, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33651392

RESUMO

Gas-phase electrophoresis yields size distributions of polydisperse, aerosolized analytes based on electrophoretic principles. Nanometer-sized, surface-dry, single-charged particles are separated in a high laminar sheath flow of particle-free air and an orthogonal tunable electric field. Additionally, nano Electrospray Gas-Phase Electrophoretic Mobility Molecular Analyzer (nES GEMMA) data are particle-number based. Therefore, small particles can be detected next to larger ones without a bias, for example, native proteins next to their aggregates. Analyte transition from the liquid to the gas phase is a method inherent prerequisite. In this context, nonvolatile sample buffers influence results. In the worst case, the (bio-)nanoparticle signal is lost due to an increased baseline and unspecific clustering of nonvolatile components. We present a novel online hyphenation of liquid chromatography and gas-phase electrophoresis, coupling a size-exclusion chromatography (SEC) column to an advanced nES GEMMA. Via this novel approach, it is possible to (i) separate analyte multimers already present in liquid phase from aggregates formed during the nES process, (ii) differentiate liquid phase and spray-induced multimers, and (iii) to remove nonvolatile buffer components online before SEC-nES GEMMA analysis. Due to these findings, SEC-nES GEMMA has the high potential to help to understand aggregation processes in biological buffers adding the benefit of actual size determination for noncovalent assemblies formed in solution. As detection and characterization of protein aggregation in large-scale pharmaceutical production or sizing of noncovalently bound proteins are findings directly related to technologically and biologically relevant situations, we proposed the presented method to be a valuable addition to LC-MS approaches.


Assuntos
Cromatografia em Gel , Eletroforese , Agregados Proteicos , Proteínas
16.
Anal Bioanal Chem ; 413(30): 7341-7352, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34622320

RESUMO

The emerging role of extracellular vesicles (EVs) as biomarkers and their envisioned therapeutic use require advanced techniques for their detailed characterization. In this context, we investigated gas-phase electrophoresis on a nano electrospray gas-phase electrophoretic mobility molecular analyzer (nES GEMMA, aka nES differential mobility analyzer, nES DMA) as an alternative to standard analytical techniques. In gas-phase electrophoresis, single-charged, surface-dry, native, polydisperse, and aerosolized analytes, e.g., proteins or bio-nanoparticles, are separated according to their electrophoretic mobility diameter, i.e., globular size. Subsequently, monodisperse particles are counted after a nucleation step in a supersaturated atmosphere as they pass a focused laser beam. Hence, particle number concentrations are obtained in accordance with recommendations of the European Commission for nanoparticle characterization (2011/696/EU from October 18th, 2011). Smaller sample constituents (e.g., co-purified proteins) can be detected next to larger ones (e.g., vesicles). Focusing on platelet-derived EVs, we compared different vesicle isolation techniques. In all cases, nanoparticle tracking analysis (NTA) confirmed the presence of vesicles. However, nES GEMMA often revealed a significant co-purification of proteins from the sample matrix, precluding gas-phase electrophoresis of less-diluted samples containing higher vesicle concentrations. Therefore, mainly peaks in the protein size range were detected. Mass spectrometry revealed that these main contaminants belonged to the group of globulins and coagulation-related components. An additional size exclusion chromatography (SEC) step enabled the depletion of co-purified, proteinaceous matrix components, while a label-free quantitative proteomics approach revealed no significant differences in the detected EV core proteome. Hence, the future in-depth analysis of EVs via gas-phase electrophoresis appears feasible. Platelet-derived extracellular vesicles (EVs)with/without additional size exclusion chromatographic (SEC) purification were subjected to nanoparticle tracking analysis (NTA) and gas-phase electrophoresis (nES GEMMA). The latter revealed presence of co-purified proteins, targetable via mass spectrometry (MS). MS also revealed that SEC did not influence EV protein content. To conclude, nES GEMMA is a valuable tool for quality control of EV-containing samples under native conditions allowing for detection of co-purified proteins from complex matrices.


Assuntos
Ensaio de Desvio de Mobilidade Eletroforética/métodos , Vesículas Extracelulares/metabolismo , Espectrometria de Massas por Ionização por Electrospray/métodos , Gases , Humanos , Espectrometria de Massas por Ionização por Electrospray/instrumentação
17.
Med Vet Entomol ; 35(2): 225-229, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33063897

RESUMO

Antibiotic-resistant bacteria pose a major threat to global health in the 21st century, requiring a quick, cheap and effective response from public health officials. This study evaluated the antimicrobial activity of native excretions/secretions (NES) produced by third instar (3 days old) larvae of Calliphora vicina using a protocol adapted from the Institute of Clinical and Laboratory Standards (CLSI). The microorganisms tested were: Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and the fungus Candida albicans. After the incubation period, the suspensions were diluted and spread on nutrient agar plates to count the colony-forming units. A turbidimetric test also was carried out to test the action of the NES of C. vicina against S. aureus, a very common bacterial species, with an enormous capacity for adaption and resistance, being one of the bacteria of medical importance that causes the most hospital and community infections in the world. According to our results, the NES of C. vicina exhibits antimicrobial activity at different dilutions, being most effective against the gram-negative bacteria E. coli and K. pneumoniae.


Assuntos
Antibacterianos , Antifúngicos , Produtos Biológicos , Calliphoridae/metabolismo , Bactérias Gram-Negativas/efeitos dos fármacos , Animais , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Produtos Biológicos/metabolismo , Produtos Biológicos/farmacologia , Candida albicans , Dípteros , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Larva/metabolismo , Testes de Sensibilidade Microbiana/métodos , Staphylococcus aureus/efeitos dos fármacos
18.
Int J Mol Sci ; 22(24)2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34948016

RESUMO

Glioblastoma (GBM) remains the leading cause of cancer-related deaths with the lowest five-year survival rates among all of the human cancers. Multiple factors contribute to its poor outcome, including intratumor heterogeneity, along with migratory and invasive capacities of tumour cells. Over the last several years Doublecortin (DCX) has been one of the debatable factors influencing GBM cells' migration. To resolve DCX's ambiguous role in GBM cells' migration, we set to analyse the expression patterns of DCX along with Nestin (NES) and Oligodendrocyte lineage transcription factor 2 (OLIG2) in 17 cases of GBM, using immunohistochemistry, followed by an analysis of single-cell RNA-seq data. Our results showed that only a small subset of DCX positive (DCX+) cells was present in the tumour. Moreover, no particular pattern emerged when analysing DCX+ cells relative position to the tumour margin. By looking into single-cell RNA-seq data, the majority of DCX+ cells were classified as non-cancerous, with a small subset of cells that could be regarded as glioma stem cells. In conclusion, our findings support the notion that glioma cells express DCX; however, there is no clear evidence to prove that DCX participates in GBM cell migration.


Assuntos
Neoplasias Encefálicas/metabolismo , Proteína Duplacortina/metabolismo , Perfilação da Expressão Gênica/métodos , Glioblastoma/metabolismo , Nestina/metabolismo , Fator de Transcrição 2 de Oligodendrócitos/metabolismo , Neoplasias Encefálicas/genética , Movimento Celular , Proteína Duplacortina/genética , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Heurística , Humanos , Processamento de Imagem Assistida por Computador , Microscopia Confocal , Metástase Neoplásica , Células-Tronco Neoplásicas/metabolismo , Nestina/genética , Fator de Transcrição 2 de Oligodendrócitos/genética , Análise de Sequência de RNA , Análise de Célula Única , Análise de Sobrevida
19.
Int J Mol Sci ; 22(6)2021 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-33799461

RESUMO

Small extracellular vesicles have been intensively studied as a source of biomarkers in neurodegenerative disorders. The possibility to isolate neuron-derived small extracellular vesicles (NDsEV) from blood represents a potential window into brain pathological processes. To date, the absence of sensitive NDsEV isolation and full proteome characterization methods has meant their protein content has been underexplored, particularly for individual patients. Here, we report a rapid method based on an immunoplate covalently coated with mouse monoclonal anti-L1CAM antibody for the isolation and the proteome characterization of plasma-NDsEV from individual Parkinson's disease (PD) patients. We isolated round-shaped vesicles with morphological characteristics consistent with exosomes. On average, 349 ± 38 protein groups were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, 20 of which are annotated in the Human Protein Atlas as being highly expressed in the brain, and 213 were shared with a reference NDsEV dataset obtained from cultured human neurons. Moreover, this approach enabled the identification of 23 proteins belonging to the Parkinson disease KEGG pathway, as well as proteins previously reported as PD circulating biomarkers.


Assuntos
Biomarcadores/sangue , Vesículas Extracelulares/genética , Doença de Parkinson/sangue , Proteoma/genética , Cromatografia Líquida , Exossomos/metabolismo , Vesículas Extracelulares/metabolismo , Humanos , Neurônios/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/patologia , Proteômica , Espectrometria de Massas em Tandem
20.
Biochem Cell Biol ; 98(4): 449-457, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31955591

RESUMO

Heart failure (HF) is associated with a considerable number of symptoms and significantly impaired health for humans, including reduced quality of life and physical functioning. Previous studies have indicated that miRNAs have important roles in regulating the development of HF. MiR-1180 is involved in the proliferation, migration, invasiveness, and chemoresistance of cancer cells; however, the underlying mechanisms and role of miR-1180 in the functioning of cardiomyocytes remains unclear. In this study, we found that miR-1180 promotes cell activity and cell cycle processes by driving energy generation through NKIRAS2, which declines over time during development. The expression of miR-1180 is down-regulated in cells subjected to hypoxia-reoxygenation, and use of an miR-1180 mimic significantly reduced myocardial injury and cell apoptosis. In addition, miR-1180 regulates the NFκB pathway through NKIRAS2 in cardiomyocytes. These findings suggest that miR-1180 maybe a novel therapeutic target for use in getting cardiomyocytes to re-enter the cell cycle as well as for cardiac repair following myocardial injury.


Assuntos
Proteínas de Transporte/metabolismo , Ciclo Celular , Embrião de Mamíferos/fisiologia , MicroRNAs/metabolismo , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/fisiologia , NF-kappa B/metabolismo , Animais , Apoptose , Proteínas de Transporte/genética , Gatos , Modelos Animais de Doenças , Embrião de Mamíferos/citologia , Hipóxia/fisiopatologia , Masculino , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/citologia , NF-kappa B/genética , Oxigênio/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
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