Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
1.
PLoS One ; 18(8): e0290312, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37616208

RESUMO

Fibropapillomatosis (FP) is a disease characterized by epithelial tumors that can impede life-sustaining activities of sea turtles, especially green turtles (Chelonia mydas). FP is caused by a herpesvirus, but environmental factors are also thought to play a role in triggering FP tumor growth. In this study, we evaluate the epidemiology of FP tumors in green turtles along the coast of Espírito Santo, Brazil, a region where juvenile green turtles are known to aggregate with high FP prevalence. A dataset comprising 2024 beach-cast green turtles recorded through daily beach surveys on 400 km of coastline from 2018 to 2021 (inclusive) was evaluated. FP tumors were recorded in 40.9% of the individuals in this dataset, and presence of FP tumors was predicted by individual variables (presence of marine leeches, stranding code, curved carapace length, body mass-size residual) and characteristics of the stranding site (distance to nearest metallurgical plant, mean sea surface salinity (SSS), annual range of sea surface temperature (SST)). Additionally, a second dataset comprising detailed information about the size and anatomical distribution of tumors in 271 green turtles with FP from the same region was evaluated. Hierarchical clustering analysis revealed these turtles could be classified in three groups according to the anatomical distribution of their tumors, and in turn the group to which each turtle was assigned could be predicted by the study period (2010-2014 vs. 2018-2022) and by characteristics of the stranding/capture site (green turtle stranding density, mean sea surface chlorophyll-a concentration, mean SSS, mean SST, annual range of SST). These results corroborate that individual and environmental factors play a significant role driving FP epidemiology. Furthermore, the results suggest that rather than behaving as a single entity, FP may be seen as a mosaic of distinct anatomical patterns that are not necessarily driven by the same environmental factors.


Assuntos
Carcinoma , Tartarugas , Animais , Brasil/epidemiologia , Exoesqueleto , Tamanho Corporal
2.
Rev Esp Enferm Dig ; 115(10): 567-573, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37170542

RESUMO

INTRODUCTION: immune checkpoint inhibitors (ICI) are increasingly used to treat several types of cancer. These drugs lead to a wide range of toxicities. Immune-related gastrointestinal adverse events are common and potentially severe. In this manuscript, we recount the real clinical experience in a tertiary center. METHODS: a retrospective and observational study was conducted in adult patients under ICI treatment. Included patients had been referred to the Gastrointestinal Service of Hospital Universitario Vall d'Hebron for evaluation of severe toxicities, from January 2017 to January 2020, for whom the clinical, epidemiological and evolutive data were collected. RESULTS: a total of 18 patients were included. Fifty-five percent received anti-programmed cell death protein 1 (PD-1)/anti-programmed death-ligand 1 (anti PD-L1), 11 % received anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) and 33 % received both treatments. The toxicities were manifested as enterocolitis, microscopic colitis and gastritis. Upper gastrointestinal endoscopy was performed in seven patients; all were proved to have histological changes on duodenum biopsies. Treatment was stopped in all patients and steroids were initiated. Sixty-six per cent achieved clinical remission with steroids. Five patients received anti-TNF treatment (infliximab). Only one of the five had responded. Two anti-TNF refractory patients received ustekinumab, with an appropriate clinical response. One patient received apheresis granulocyte as concomitant treatment. A patient with a steroid-dependent course started vedolizumab. Three patients had other immune-related adverse events. CONCLUSION: gastrointestinal immune-related adverse events are acquiring a higher profile in daily practice and gastroenterologists play an even greater role in the management of these patients.

3.
Biol Reprod ; 108(2): 229-240, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-36308432

RESUMO

Membrane fusion in sperm cells is crucial for acrosomal exocytosis and must be preserved to ensure fertilizing capacity. Evolutionarily conserved protein machinery regulates acrosomal exocytosis. Molecular chaperones play a vital role in spermatogenesis and post-testicular maturation. Cysteine string protein (CSP) is a member of the Hsp40 co-chaperones, and the participation of molecular chaperones in acrosomal exocytosis is poorly understood. In particular, the role of CSP in acrosomal exocytosis has not been reported so far. Using western blot and indirect immunofluorescence, we show that CSP is present in human sperm, is palmitoylated, and predominantly bound to membranes. Moreover, using functional assays and transmission electron microscopy, we report that blocking the function of CSP avoided the assembly of trans-complexes and inhibited exocytosis. In summary, here, we describe the presence of CSP in human sperm and show that this protein has an essential role in membrane fusion during acrosomal exocytosis mediating the trans-SNARE complex assembly between the outer acrosomal and plasma membranes. In general, understanding CSP's role is critical in identifying new biomarkers and generating new rational-based approaches to treat male infertility.


Assuntos
Acrossomo , Proteínas SNARE , Humanos , Masculino , Acrossomo/metabolismo , Exocitose/fisiologia , Sêmen/metabolismo , Proteínas SNARE/metabolismo , Espermatozoides/metabolismo
4.
Int J Mol Sci ; 23(18)2022 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-36142786

RESUMO

The development of biomarkers for inflammatory bowel disease (IBD) diagnosis would be relevant in a generalized context. However, intercontinental investigation on these microbial biomarkers remains scarce. We examined taxonomic microbiome variations in IBD using published DNA shotgun metagenomic data. For this purpose, we used sequenced data from our previous Spanish Crohn's disease (CD) and ulcerative colitis (UC) cohort, downloaded sequence data from a Chinese CD cohort, and downloaded taxonomic and functional profiling tables from a USA CD and UC cohort. At the global level, geographical location and disease phenotype were the main explanatory covariates of microbiome variations. In healthy controls (HC) and UC, geography turned out to be the most important factor, while disease intestinal location was the most important one in CD. Disease severity correlated with lower alpha-diversity in UC but not in CD. Across geography, alpha-diversity was significantly different independently of health status, except for CD. Despite recruitment from different countries and with different disease severity scores, CD patients may harbor a very similar microbial taxonomic profile. Our study pointed out that geographic location, disease activity status, and other environmental factors are important contributing factors in microbiota changes in IBD. We therefore strongly recommend taking these factors into consideration for future IBD studies to obtain globally valid and reproducible biomarkers.


Assuntos
Colite Ulcerativa , Doença de Crohn , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Biomarcadores , Colite Ulcerativa/diagnóstico , Doença de Crohn/diagnóstico , Fezes , Microbioma Gastrointestinal/genética , Humanos
5.
Biochem J ; 478(2): 407-422, 2021 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33393983

RESUMO

Insulin stimulates glucose uptake in muscle cells by rapidly redistributing vesicles containing GLUT4 glucose transporters from intracellular compartments to the plasma membrane (PM). GLUT4 vesicle fusion requires the formation of SNARE complexes between vesicular VAMP and PM syntaxin4 and SNAP23. SNARE accessory proteins usually regulate vesicle fusion processes. Complexins aide in neuro-secretory vesicle-membrane fusion by stabilizing trans-SNARE complexes but their participation in GLUT4 vesicle fusion is unknown. We report that complexin-2 is expressed and homogeneously distributed in L6 rat skeletal muscle cells. Upon insulin stimulation, a cohort of complexin-2 redistributes to the PM. Complexin-2 knockdown markedly inhibited GLUT4 translocation without affecting proximal insulin signalling of Akt/PKB phosphorylation and actin fiber remodelling. Similarly, complexin-2 overexpression decreased maximal GLUT4 translocation suggesting that the concentration of complexin-2 is finely tuned to vesicle fusion. These findings reveal an insulin-dependent regulation of GLUT4 insertion into the PM involving complexin-2.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Insulina/farmacologia , Mioblastos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Adaptadoras de Transporte Vesicular/genética , Animais , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Células Cultivadas , Transportador de Glucose Tipo 4/genética , Insulina/genética , Insulina/metabolismo , Músculo Esquelético/citologia , Mioblastos/efeitos dos fármacos , Proteínas do Tecido Nervoso/genética , Transporte Proteico/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Transdução de Sinais , Proteínas rac1 de Ligação ao GTP/metabolismo
6.
Rev Esp Enferm Dig ; 113(5): 313-317, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33213168

RESUMO

BACKGROUND AND AIM: ustekinumab is a fully human monoclonal antibody against IL-12/23, approved for induction and maintenance treatment of Crohn's disease (CD). Real-life data shows its true effectiveness in terms of clinical and endoscopic response. However, there is little information regarding health-related quality of life (HRQoL) in CD patients receiving ustekinumab. The main aim of this study was to define long-term clinical remission and HRQoL normalization. The clinical predictive factors of clinical remission were investigated as a secondary aim. METHODS: a retrospective, observational study was performed in CD patients under ustekinumab treatment in the Hospital Vall d'Hebron, between January 2009 and January 2019. Clinical remission was defined using the Crohn's Disease Activity Index (CDAI) and HRQoL normalization was defined by the 36-item Inflammatory Bowel Disease Questionnaire (IBDQ). RESULTS: thirty-three patients were included. The average disease evolution was eleven years (standard deviation [SD]: 8), perianal disease was present in 13 patients (39 %), 30 patients (91 %) had previously been treated with alfa tumor necrosis factor antagonists (anti-TNF) agents and 22 patients (67 %) had a history of intestinal resection. Twenty-four patients (73 %) had undergone one year of treatment. Seventeen patients (51 %) reached clinical remission and six (18 %) restored the HRQoL. No predictors of clinical remission were identified. CONCLUSIONS: ustekinumab shows clinical effectiveness in real-life conditions similar to previous data. Normalization of HRQoL is low compared to clinical remission, which may be due to the inaccuracy of the indicator and the severe disease course. Such normalization is a challenge for physicians dealing with inflammatory bowel diseases.


Assuntos
Doença de Crohn , Qualidade de Vida , Doença de Crohn/tratamento farmacológico , Humanos , Indução de Remissão , Estudos Retrospectivos , Inibidores do Fator de Necrose Tumoral , Ustekinumab/uso terapêutico
7.
Ticks Tick Borne Dis ; 10(6): 101256, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31255535

RESUMO

Ehrlichia spp. are obligatory intracellular microorganisms that infect hematopoietic, endothelial or blood cells of mammals. Ticks are the only vectors of these agents in nature. To date, the role of birds and their associated ticks as reservoirs of ehrlichiae remains almost unexplored. In this study, we performed a molecular screening for bacteria of Anaplasmataceae family in samples of spleen (n = 72) and lung (n = 17), recovered from 72 carcasses of Magellanic penguins (Spheniscus magellanicus) in Brazil and Chile. One apparently unengorged tick (Ixodes uriae) was also collected while wandering upon one of the carcasses and submitted to molecular analyses as well. Through conventional and nested PCR protocols three genes (16S rRNA, dsb and groEL) of a new Ehrlichia sp. were partially characterized upon organs of three penguins and in the tick coming from Magdalena Island (Chile). First matches after BLASTn comparisons showed that our sequences share 99.4% (16S rRNA), 94.6% (groEL) and 79.3% (dsb) of identity with "Candidatus Ehrlichia ornithorhynchi", Ehrlichia sp. NS101 and Ehrlichia canis CCZ, respectively. Matrixes of genetic distance including other representatives of the Ehrlichia genus point a 99.4%, 94.0%, and 80.0% of identity with 16S rRNA, groEL and dsb genes from Ehrlichia sp. It25, Ehrlichia sp. NS101, and Ehrlichia chaffeensis San Louis, respectively. A Bayesian phylogenetic analysis of Anaplasmataceae 16S rRNA gene places the detected Ehrlichia sp. into a group with Ehrlichia sp. BAT and Ehrlichia sp. Natal. Although depicting different topologies, Bayesian unrooted phylogenetic trees constructed for groEL and dsb genes position this Ehrlichia sp. into well-supported branches, which reinforces the finding of a new taxon. For the moment, any pathogenic effect of this new Ehrlichia sp. on penguins is still unknown. However, this fact becomes important to assess from a conservation point of view since populations of Magellanic penguins are currently threatened and in an ongoing decrease.


Assuntos
Ehrlichia/classificação , Ixodes/microbiologia , Spheniscidae/microbiologia , Animais , Proteínas de Bactérias/análise , Chaperonina 60/análise , Chile , Ehrlichia/fisiologia , Feminino , Filogenia , RNA Bacteriano/análise , RNA Ribossômico 16S/análise
8.
BMC Cancer ; 19(1): 328, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30953488

RESUMO

BACKGROUND: Cancer cells evolve and constitute heterogeneous populations that fluctuate in space and time and are subjected to selection generating intratumor heterogeneity. This phenomenon is determined by the acquisition of genetic/epigenetic alterations and their selection over time which has clinical implications on drug resistance. METHODS: DNA extracted from different tumor cell populations (breast carcinomas, cancer cell lines and cellular clones) were analyzed by MS-MLPA. Methylation profiles were used to generate a heterogeneity index to quantify the magnitude of epigenetic heterogeneity in these populations. Cellular clones were obtained from single cells derived of MDA-MB 231 cancer cell lines applying serial limiting dilution method and morphology was analyzed by optical microscopy and flow cytometry. Clones characteristics were examined through cellular proliferation, migration capacity and apoptosis. Heterogeneity index was also calculated from beta values derived from methylation profiles of TCGA tumors. RESULTS: The study of methylation profiles of 23 fresh breast carcinomas revealed heterogeneous allele populations in these tumor pieces. With the purpose to measure the magnitude of epigenetic heterogeneity, we developed an heterogeneity index based on methylation information and observed that all tumors present their own heterogeneity level. Applying the index calculation in pure cancer cell populations such as cancer cell lines (MDA-MB 231, MCF-7, T47D, HeLa and K-562), we also observed epigenetic heterogeneity. In addition, we detected that clones obtained from the MDA-MB 231 cancer cell line generated their own new heterogeneity over time. Using TCGA tumors, we determined that the heterogeneity index correlated with prognostic and predictive factors like tumor size (p = 0.0088), number of affected axillary nodes (p = 0.007), estrogen receptor expression (p < 0.0001) and HER2 positivity (p = 0.0007). When we analyzed molecular subtypes we found that they presented different heterogeneity levels. Interestingly, we also observed that all mentioned tumor cell populations shared a similar Heterogeneity index (HI) mean. CONCLUSIONS: Our results show that each tumor presents a unique epigenetic heterogeneity level, which is associated with prognostic and predictive factors. We also observe that breast tumor subtypes differ in terms of epigenetic heterogeneity, which could serve as a new contribution to understand the different prognosis of these groups.


Assuntos
Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Metilação de DNA/genética , Epigênese Genética , Adulto , Apoptose/genética , Mama/patologia , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/mortalidade , Carcinoma Ductal de Mama/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Ilhas de CpG/genética , Conjuntos de Dados como Assunto , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Prognóstico , Regiões Promotoras Genéticas/genética
9.
Rev. bras. parasitol. vet ; 28(1): 68-79, Jan.-Mar. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-990803

RESUMO

Abstract Avian malaria is one of the most important diseases of captive penguins. We employed morphometric techniques to evaluate hepatic hemosiderosis in rehabilitating wild Magellanic penguins (Spheniscus magellanicus) that were negative (n = 9) or naturally infected by different subgenera of Plasmodium spp. (n = 24), according with: Plasmodium subgenera (Haemamoeba, Huffia, Other lineages, and Unidentified lineages), severity of Plasmodium histopathological lesions, and concurrent diseases, age class (juvenile or adult plumage), sex (male, female or not determined), body score (emaciated, thin, good, excellent, not available), molt, presence or absence of oil contamination upon admission, iron supplementation, and rehabilitation center. The percentage of the area occupied by hemosiderin was called 'Index of Hepatic Hemosiderosis (IHH)'. Plasmodium-positive females presented significantly higher IHH values (17.53 ± 12.95%) than males (7.20 ± 4.25%; p = 0.041). We observed higher levels of congestion (p = 0.0182) and pneumonia (p = 0.0250) severity between Unidentified lineages vs. Huffia. We believe that the hepatic hemosiderosis observed in this study was multifactorial, the result of pathological processes caused by malaria, molting, hemoglobin and myoglobin catabolism during migration, anemia, concomitant diseases, and iron supplementation, all possibly potentiated by decreased liver mass. Further studies are needed to clarify the mechanisms of these hypotheses.


Resumo Malária aviária é uma das mais relevantes doenças em pinguins cativos. Foram aplicadas técnicas morfométricas para avaliar a hemossiderose hepática em pinguins-de-Magalhães (Spheniscus magellanicus ) de vida livre em reabilitação negativos (n = 9) e naturalmente infectados por diferentes subgêneros de Plasmodium spp. (n = 24), quanto a: subgênero de Plasmodium (Haemamoeba , Huffia, Outras Linhagens, e Linhagens não identificadas), severidade das lesões histopatológicas causadas por Plasmodium e doenças concomitantes, faixa etária (plumagem juvenil ou adulta), sexo (macho, fêmea, indeterminado), condição corporal (emaciado, magro, bom, excelente, indisponível), muda, presença/ausência de óleo a admissão, suplementação de ferro, e centro de reabilitação. A porcentagem da área ocupada por hemossiderina foi denominada "Índice de Hemossiderose Hepática (IHH)". Fêmeas Plasmodium -positivas apresentaram IHH significativamente mais elevado que machos, respectivamente, 17,53 ± 12,95% e 7,20 ± 4,25% (p = 0,041). Níveis mais elevados de congestão (p = 0,0182) e pneumonia (p = 0,0250) foram observados entre Linhagens não identificadas vs. Huffia. Possivelmente, a hemossiderose hepática observada nesse estudo seja multifatorial, resultado de processos patológicos causados por malária, muda, catabolismo de hemoglobina e mioglobina durante a migração, anemia, doenças concomitantes e suplementação de ferro, potencialmente intensificados por massa hepática reduzida. Estudos complementares são necessários para esclarecer os mecanismos de tais hipóteses.


Assuntos
Animais , Masculino , Feminino , Plasmodium/classificação , Doenças das Aves/parasitologia , Spheniscidae/parasitologia , Hemossiderose/parasitologia , Hepatopatias/parasitologia , Malária Aviária/parasitologia , Doenças das Aves/patologia , Índice de Gravidade de Doença , Hemossiderose/patologia , Hepatopatias/patologia , Malária Aviária/complicações , Malária Aviária/patologia , Animais Selvagens
11.
Mol Immunol ; 113: 87-92, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-29631761

RESUMO

Dendritic cells (DCs) trigger CD8 + T cell responses after the internalization of exogenous antigens in a process called cross-presentation. Multiple intracellular transport events within the endocytic and secretory routes take place in order to accomplish this fundamental immunological process. The endomembrane system can be envisioned as a complex network of membrane domains coordinately working in the fusion of organelles, the budding of vesicles and tubules, and modifying the molecular composition of the limiting membranes. In this context of tightly regulated and dynamic endomembrane transport, small GTPases of the Rab family display a pivotal role by organizing membrane microdomains and defining specific identities to the different intracellular compartments. In this review, we synthesize and update the current knowledge about Rab22a, which has been involved in several immune functions. In this way, we analyze the intracellular localization of Rab22a and its important role in the endocytic recycling, including its relevance during MHC-I trafficking, antigen cross-presentation by DCs and the formation of T cell conjugates. We also describe how different pathogenic microorganisms hijack Rab22a functions to achieve efficient infection and intracellular survival strategies. Furthermore, we examine the oncogenic properties of Rab22a and how its expression determines the progression of many tumors. In summary, we highlight the role of Rab22a as a key effector of the intracellular trafficking that could be exploited in future therapies to modulate the immune system.


Assuntos
Proteínas rab de Ligação ao GTP/imunologia , Animais , Apresentação de Antígeno/imunologia , Apresentação Cruzada/imunologia , Células Dendríticas/imunologia , Endocitose/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Transporte Proteico/imunologia
12.
PLoS One ; 13(12): e0209007, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30562391

RESUMO

The main motivation for this study was to determine the occurrence of Toxoplasma gondii, a cosmopolitan widespread zoonotic parasite distribution that can infect a wide variety of mammals and birds, in Magellanic penguins (Spheniscus magellanicus) in Brazil. In recent decades there has been a significant increase in the number of penguins originating from Argentinian and Chilean Patagonia, where these birds are born, that arrive on the Brazilian coast, where many of them are stranded and rescued. Tissue samples were collected from 330 individuals surveyed from 2012-2015 at the Institute for Marine Animal Research and Rehabilitation (IPRAM) located in Cariacica, state of Espirito Santo, Brazil. Serum were collected from 145 animals surveyed in 2015 for the detection of anti-T. gondii antibodies using the Modified Agglutination Test (MAT ≥20) and 18 birds were positive, with titers of 20 (7 birds), 40 (9 birds) and 80 (2 birds). Mouse bioassay for the isolation of T. gondii was performed using tissues from 54 penguins that were also surveyed in 2015, but no isolates were obtained. DNA from tissue samples of 330 individuals was PCR amplified and sequenced to detect tissue cyst forming coccidians by using pan sarcocystids-directed primers (based on 18S rDNA). These samples were from animals surveyed in 2015 and from frozen stocked tissues from animals surveyed in the years 2012 and 2013. The positives were PCR amplified and sequenced with genus Sarcocystis-specific primers (based on internal transcribed spacer 1, RNA polymerase beta subunit coding gene, and cytochrome B coding gene) and with Sarcocystis falcatula/Sarcocystis neurona- specific primers (based on surface antigens SAG2, SAG3 and SAG4). Sixteen (3.0%) of pectoral muscle samples were positive by all the seven molecular markers and all the samples were identical to each other. Organisms close related to Sarcocystis falcatula were confirmed in all cases. This is the first report on molecular detection of infection by S. falcatula-related organisms and the first report of seropositivity for T. gondii in free-living Magellanic penguins in Brazil. Felids and didephid opossums are definitive hosts of T. gondii and S. falcatula, respectively. Where the penguins acquire the infective forms of the parasites shed by the terrestrial mammals remains to be elucidated.


Assuntos
Doenças das Aves/epidemiologia , Coccídios , Coccidiose/veterinária , Spheniscidae/parasitologia , Animais , Antígenos de Protozoários/sangue , Doenças das Aves/sangue , Doenças das Aves/imunologia , Brasil , Coccídios/imunologia , Coccidiose/sangue , Coccidiose/epidemiologia , Coccidiose/imunologia , Músculo Esquelético/imunologia , Músculo Esquelético/parasitologia , Filogenia , Spheniscidae/sangue , Spheniscidae/genética , Spheniscidae/imunologia
13.
Int J Nanomedicine ; 13: 8075-8086, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30568446

RESUMO

BACKGROUND: Nanoparticles' intracellular fate requires proper internalization. Most cells make use of a battery of internalization pathways, but some are practically sealed, as they lack the biochemical machinery for cellular intake. Non-endocytic cells, such as mammals' spermatozoa, challenge standard drug-delivery strategies. PURPOSE: In this article, we present a gold nanoprobe that permeates the external and internal membranes of human sperm. METHODS: Our design makes use of a gold nanoparticle functionalized with a membrane-permeable cysteine-rich recombinant protein. The chimeric protein contains two units of physiologically active metallothioneins (MT) that also provide binding motifs to gold and a cell-penetrating-peptide sequence (CPP) that confers cell permeability to the nanoparticle. RESULTS: Transmission electron microscopy, indirect immunofluorescence, and functional assays show that the nanoprobe is readily internalized in sperm, without compromising cell integrity, while preserving MT's physiological activity. Our findings highlight the potential of CPP-functionalized nanogold for investigating the physiology of otherwise impermeable non-endocytic cells.


Assuntos
Permeabilidade da Membrana Celular , Endocitose , Ouro/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Acrossomo/efeitos dos fármacos , Acrossomo/metabolismo , Sequência de Aminoácidos , Animais , Permeabilidade da Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/farmacologia , Exocitose/efeitos dos fármacos , Humanos , Masculino , Metalotioneína/metabolismo , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Espermatozoides/metabolismo , Espermatozoides/ultraestrutura
14.
Proc Natl Acad Sci U S A ; 115(50): E11847-E11856, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30478045

RESUMO

Using a de novo peptide inhibitor, Corza6 (C6), we demonstrate that the human voltage-gated proton channel (hHv1) is the main pathway for H+ efflux that allows capacitation in sperm and permits sustained reactive oxygen species (ROS) production in white blood cells (WBCs). C6 was identified by a phage-display strategy whereby ∼1 million novel peptides were fabricated on an inhibitor cysteine knot (ICK) scaffold and sorting on purified hHv1 protein. Two C6 peptides bind to each dimeric channel, one on the S3-S4 loop of each voltage sensor domain (VSD). Binding is cooperative with an equilibrium affinity (Kd) of ∼1 nM at -50 mV. As expected for a VSD-directed toxin, C6 inhibits by shifting hHv1 activation to more positive voltages, slowing opening and speeding closure, effects that diminish with membrane depolarization.


Assuntos
Canais Iônicos/fisiologia , Leucócitos/metabolismo , Capacitação Espermática/fisiologia , Reação Acrossômica/efeitos dos fármacos , Reação Acrossômica/fisiologia , Sequência de Aminoácidos , Sítios de Ligação , Células HEK293 , Humanos , Canais Iônicos/antagonistas & inibidores , Canais Iônicos/genética , Masculino , Potenciais da Membrana , Biblioteca de Peptídeos , Peptídeos/química , Peptídeos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória , Capacitação Espermática/efeitos dos fármacos , Toxinas Biológicas/química , Toxinas Biológicas/farmacologia
15.
Rev. méd. hondur ; 85(1-2): 27-29, ene.-jun. 2017.
Artigo em Espanhol | LILACS | ID: biblio-884083

RESUMO

Introducción. Las inmunodeficiencias primarias son un grupo de enfermedades de origen genético que implican altera - ciones asociadas a la respuesta inmunológica. El infra diagnóstico de estas conlleva al retraso de tratamiento, evitables en gran parte; Entre estas existe el síndrome de Wiskott-Aldrich; es un trastorno raro, ligado al cromosoma X, recesivo, que se caracteriza por trom - bocitopenia, eczema e inmunodeficiencia donde su tratamiento curativo es el trasplante de medula ósea. CASO CLÍNICO : Paciente de 10 años, con antecedentes de múltiples hospitalizaciones por procesos infecciosos importantes: neumonías recurrentes, menin - gitis, diarreas, erupción cutánea generalizada y trombocitopenia de hasta 9,000 mm³. Después de múltiples estudios realizados, se confirma el diagnóstico de síndrome de Wiskott -Aldrich por inmunogenetica (mutación del gen WAS) y mediante colaboración médica internacional, se realiza trasplante de médula ósea con posterior resolución de su enfermedad. DISCUSION: Las inmunodeficiencias primarias son patologías más comunes de lo que se creía (prevalencia de hasta 1/1200), la evidencia de aparición y su importancia clínica deben ser tomadas en consideración. En este caso de Síndrome de Wiskot-Aldrich en donde el diagnóstico definitivo es in - munogenetico, (actualmente el país no cuenta), además de tratamiento inmuno-oncológico adecuado, el paciente pudo sobrevivir y mejorar su calidad de vida gracias a soporte investigativo y terapéutico multinacional. Existen colaboraciones multicentricas como el consorcio de tratamiento inmunodeficiencias primarias, que tienen como objetivo colaborar activamente en el diagnóstico y tratamien - to estos casos, salvaguardando la vida de estos pacientes y ayudando a comprender estas enfermedades raras...(AU)


Assuntos
Humanos , Doenças Autoimunes , Transplante de Medula Óssea/métodos , Trombocitopenia/complicações , Síndrome de Wiskott-Aldrich/diagnóstico , Cromossomo X
16.
EMBO Rep ; 17(12): 1753-1765, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27861124

RESUMO

Cross-presentation by MHC class I molecules allows the detection of exogenous antigens by CD8+ T lymphocytes. This process is crucial to initiate cytotoxic immune responses against many pathogens (i.e., Toxoplasma gondii) and tumors. To achieve efficient cross-presentation, dendritic cells (DCs) have specialized endocytic pathways; however, the molecular effectors involved are poorly understood. In this work, we identify the small GTPase Rab22a as a key regulator of MHC-I trafficking and antigen cross-presentation by DCs. Our results demonstrate that Rab22a is recruited to DC endosomes and phagosomes, as well as to the vacuole containing T. gondii parasites. The silencing of Rab22a expression did not affect the uptake of exogenous antigens or parasite invasion, but it drastically reduced the intracellular pool and the recycling of MHC-I molecules. The knockdown of Rab22a also hampered the cross-presentation of soluble, particulate and T. gondii-associated antigens, but not the endogenous MHC-I antigen presentation through the classical secretory pathway. Our findings provide compelling evidence that Rab22a plays a central role in the MHC-I endocytic trafficking, which is crucial for efficient cross-presentation by DCs.


Assuntos
Apresentação de Antígeno , Proteínas de Transporte/metabolismo , Células Dendríticas/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Proteínas Nucleares/metabolismo , Toxoplasma/imunologia , Animais , Apresentação de Antígeno/genética , Apresentação de Antígeno/fisiologia , Células da Medula Óssea/imunologia , Células da Medula Óssea/parasitologia , Linfócitos T CD8-Positivos/imunologia , Proteínas de Transporte/genética , Apresentação Cruzada , Proteínas de Ligação a DNA , Células Dendríticas/parasitologia , Endocitose , Endossomos/metabolismo , Endossomos/parasitologia , Regulação da Expressão Gênica , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Camundongos , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Fagossomos/metabolismo , Fagossomos/parasitologia , Transporte Proteico , Proteínas de Ligação a RNA , Toxoplasma/fisiologia , Vacúolos/metabolismo , Vacúolos/parasitologia
17.
PLoS One ; 11(7): e0157416, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27383829

RESUMO

During the last decades it has been established that breast cancer arises through the accumulation of genetic and epigenetic alterations in different cancer related genes. These alterations confer the tumor oncogenic abilities, which can be resumed as cancer hallmarks (CH). The purpose of this study was to establish the methylation profile of CpG sites located in cancer genes in breast tumors so as to infer their potential impact on 6 CH: i.e. sustained proliferative signaling, evasion of growth suppressors, resistance to cell death, induction of angiogenesis, genome instability and invasion and metastasis. For 51 breast carcinomas, MS-MLPA derived-methylation profiles of 81 CpG sites were converted into 6 CH profiles. CH profiles distribution was tested by different statistical methods and correlated with clinical-pathological data. Unsupervised Hierarchical Cluster Analysis revealed that CH profiles segregate in two main groups (bootstrapping 90-100%), which correlate with breast laterality (p = 0.05). For validating these observations, gene expression data was obtained by RealTime-PCR in a different cohort of 25 tumors and converted into CH profiles. This analyses confirmed the same clustering and a tendency of association with breast laterality (p = 0.15). In silico analyses on gene expression data from TCGA Breast dataset from left and right breast tumors showed that they differed significantly when data was previously converted into CH profiles (p = 0.033). We show here for the first time, that breast carcinomas arising on different sides of the body present differential cancer traits inferred from methylation and expression profiles. Our results indicate that by converting methylation or expression profiles in terms of Cancer Hallmarks, it would allow to uncover veiled associations with clinical features. These results contribute with a new finding to the better understanding of breast tumor behavior, and can moreover serve as proof of principle for other bilateral cancers like lung, testes or kidney.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/fisiopatologia , Carcinoma/genética , Carcinoma/fisiopatologia , Ilhas de CpG , Adulto , Idoso , Estudos de Coortes , Metilação de DNA , Epigênese Genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Pessoa de Meia-Idade
18.
Pesqui. vet. bras ; Pesqui. vet. bras;36(supl.1): 65-70, June 2016. tab, ilus
Artigo em Português | LILACS, VETINDEX | ID: lil-798006

RESUMO

Este trabalho apresenta valores hematológicos e bioquímicos de pinguins-de-Magalhães (Spheniscus magellanicus) juvenis que arribaram no Espírito Santo e Rio de Janeiro, litoral sudeste do Brasil, e foram encaminhados a reabilitação. Os valores médios obtidos foram: eritrócitos 2.55±0.54 milhões/µL; hemoglobina 13,37±3,91g/dL; hematócrito 41,5±0,04%; proteína plasmática 6,34±0,81g/dL; leucócitos 16.301±6.402/µL; trombócitos 20.516±4.591 células/µL; volume corpuscular médio (VCM) 172,0±53,0 fL; concentração de hemoglobina corpuscular média (CHCM) 26,41±0,02%; alanina transaminase (ALT) 50,0±17,89 U/L; ácido úrico 8,93±3,0mg/dL; albumina 1,68±0,53g/dL; cálcio 9,7±0,57mg/dL; fósforo 10,39±8,5mg/dL e glicose 211,6±30,3mg/dL. Valores de eritrócitos, VCM e CHCM foram discrepantes em relação aos valores de referência atuais. Valores de leucócitos e trombócitos tem significado inconclusivo. Hematócrito, hemoglobina, proteína plasmática e valores bioquímicos forneceram importante contribuição para o estabelecimento de parâmetros de referência.(AU)


This paper reports hematological and biochemical values of juveniles Magellanic penguins (Spheniscus magellanicus) stranded in Espírito Santo and Rio de Janeiro, Southeastern Brazil, that were sent for rehabilitation. The average values were: erythrocytes 2.55±0,54 milhões/µL, hemoglobin 13.37±3,91g/dL, hematocrit 41.5±0.04%, plasma protein 6.34±0.81g/dL, leukocytes 16,301±6,402/µL, thrombocytes 20,516±4,591 células/µL3, mean cell volume (MCV) 172.0±53.0 fL, mean cell hemoglobin concentration (MCHC) 26.41±0.02%, alanine transaminase (ALT) 50.0±17.89 U/L, uric acid 8.93±3.0mg/dL, albumin 1.68±0.53mg/dL, calcium 9.7±0.57mg/dL, phosphorus 10.39±8.5mg/dL and glucose 211.6±30.3mg/dL. Values of erythrocytes, MCV and MCH were discrepant in relation to the current reference values. Leukocytes and thrombocytes values has meant inconclusive. Hematocrit, hemoglobin, plasma protein and biochemical values provided important contribution for the establishment of reference parameters.(AU)


Assuntos
Animais , Fenômenos Bioquímicos , Análise Química do Sangue/veterinária , Reabilitação , Spheniscidae/sangue , Testes Hematológicos/veterinária
19.
Adv Anat Embryol Cell Biol ; 220: 71-92, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27194350

RESUMO

Exocytosis is a fundamental process used by eukaryotic cells to release biological compounds and to insert lipids and proteins in the plasma membrane. Specialized secretory cells undergo regulated exocytosis in response to physiological signals. Sperm exocytosis or acrosome reaction (AR) is essentially a regulated secretion with special characteristics. We will focus here on some of these unique features, covering the topology, kinetics, and molecular mechanisms that prepare, drive, and regulate membrane fusion during the AR. Last, we will compare acrosomal release with exocytosis in other model systems.


Assuntos
Reação Acrossômica/fisiologia , Acrossomo/metabolismo , Membrana Celular/metabolismo , Exocitose/fisiologia , Acrossomo/química , Animais , Cálcio/metabolismo , Membrana Celular/química , Regulação da Expressão Gênica , Cinética , Masculino , Fusão de Membrana/fisiologia , Camundongos , Fosfatos de Fosfatidilinositol/metabolismo , Proteínas SNARE/genética , Proteínas SNARE/metabolismo , Transdução de Sinais , Sinaptotagminas/genética , Sinaptotagminas/metabolismo , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab27 de Ligação ao GTP , Proteínas rab3 de Ligação ao GTP/genética , Proteínas rab3 de Ligação ao GTP/metabolismo
20.
Biol Reprod ; 94(3): 57, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26792943

RESUMO

Acrosomal exocytosis in mammalian sperm is a regulated secretion with unusual characteristics. One of its most striking features is the postfusion loss of the outer acrosomal membrane and the overlying plasma membrane as hybrid vesicles. We have previously reported in human sperm that, by preventing the release of calcium from the acrosome, the exocytic process can be arrested at a stage where the acrosomes are profusely swollen, with invaginations of the outer acrosomal membrane. In this report, we show by transmission electron microcopy swelling with similar characteristics without arresting the exocytic process. Acrosomal swelling was observed when secretion was promoted by pharmacological and physiological inducers of the acrosome reaction that trigger exocytosis by different mechanisms. We show that progesterone- and thapsigargin-induced swelling depended on a calcium influx from the extracellular medium through store-operated calcium channels. However, calcium was dispensable when sperm were stimulated with cAMP analogs. KH7, an inhibitor of the soluble adenylyl cyclase, blocked progesterone-induced swelling. Our results indicate that swelling is a required process for acrosomal exocytosis triggered by activation of an adenylyl cyclase downstream of the opening of store-operated calcium channels.


Assuntos
Reação Acrossômica/fisiologia , Canais de Cálcio/metabolismo , AMP Cíclico/metabolismo , Transdução de Sinais/fisiologia , Espermatozoides/fisiologia , Adulto , Calcimicina/farmacologia , Humanos , Masculino , Progesterona/fisiologia , Espermatozoides/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA