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1.
Cell ; 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38986619

RESUMEN

Posterior fossa group A (PFA) ependymoma is a lethal brain cancer diagnosed in infants and young children. The lack of driver events in the PFA linear genome led us to search its 3D genome for characteristic features. Here, we reconstructed 3D genomes from diverse childhood tumor types and uncovered a global topology in PFA that is highly reminiscent of stem and progenitor cells in a variety of human tissues. A remarkable feature exclusively present in PFA are type B ultra long-range interactions in PFAs (TULIPs), regions separated by great distances along the linear genome that interact with each other in the 3D nuclear space with surprising strength. TULIPs occur in all PFA samples and recur at predictable genomic coordinates, and their formation is induced by expression of EZHIP. The universality of TULIPs across PFA samples suggests a conservation of molecular principles that could be exploited therapeutically.

2.
Genome Res ; 29(8): 1211-1222, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31249064

RESUMEN

We investigated the role of 3D genome architecture in instructing functional properties of glioblastoma stem cells (GSCs) by generating sub-5-kb resolution 3D genome maps by in situ Hi-C. Contact maps at sub-5-kb resolution allow identification of individual DNA loops, domain organization, and large-scale genome compartmentalization. We observed differences in looping architectures among GSCs from different patients, suggesting that 3D genome architecture is a further layer of inter-patient heterogeneity for glioblastoma. Integration of DNA contact maps with chromatin and transcriptional profiles identified specific mechanisms of gene regulation, including the convergence of multiple super enhancers to individual stemness genes within individual cells. We show that the number of loops contacting a gene correlates with elevated transcription. These results indicate that stemness genes are hubs of interaction between multiple regulatory regions, likely to ensure their sustained expression. Regions of open chromatin common among the GSCs tested were poised for expression of immune-related genes, including CD276 We demonstrate that this gene is co-expressed with stemness genes in GSCs and that CD276 can be targeted with an antibody-drug conjugate to eliminate self-renewing cells. Our results demonstrate that integrated structural genomics data sets can be employed to rationally identify therapeutic vulnerabilities in self-renewing cells.


Asunto(s)
Neoplasias Encefálicas/genética , Cromatina/ultraestructura , Mapeo Cromosómico/métodos , Regulación Neoplásica de la Expresión Génica , Glioblastoma/genética , Proteínas de Neoplasias/genética , Antígenos B7/antagonistas & inhibidores , Antígenos B7/genética , Antígenos B7/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Proliferación Celular , Cromatina/química , Elementos de Facilitación Genéticos , Perfilación de la Expresión Génica , Heterogeneidad Genética , Genoma Humano , Genómica/métodos , Glioblastoma/metabolismo , Glioblastoma/patología , Humanos , Terapia Molecular Dirigida , Proteínas de Neoplasias/clasificación , Proteínas de Neoplasias/metabolismo , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Cultivo Primario de Células , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Transcripción Genética
3.
Development ; 143(24): 4631-4642, 2016 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-27836963

RESUMEN

In the epithelial follicle stem cells (FSCs) of the Drosophila ovary, Epidermal Growth Factor Receptor (EGFR) signaling promotes self-renewal, whereas Notch signaling promotes differentiation of the prefollicle cell (pFC) daughters. We have identified two proteins, Six4 and Groucho (Gro), that link the activity of these two pathways to regulate the earliest cell fate decision in the FSC lineage. Our data indicate that Six4 and Gro promote differentiation towards the polar cell fate by promoting Notch pathway activity. This activity of Gro is antagonized by EGFR signaling, which inhibits Gro-dependent repression via p-ERK mediated phosphorylation. We have found that the phosphorylated form of Gro persists in newly formed pFCs, which may delay differentiation and provide these cells with a temporary memory of the EGFR signal. Collectively, these findings demonstrate that phosphorylated Gro labels a transition state in the FSC lineage and describe the interplay between Notch and EGFR signaling that governs the differentiation processes during this period.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriología , Receptores ErbB/metabolismo , Proteínas de Homeodominio/genética , Proteínas del Tejido Nervioso/genética , Folículo Ovárico/embriología , Receptores de Péptidos de Invertebrados/metabolismo , Receptores Notch/metabolismo , Proteínas Represoras/genética , Factores de Transcripción/genética , Animales , Diferenciación Celular/genética , Células Epiteliales/citología , Femenino , Proteínas de Homeodominio/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Folículo Ovárico/citología , Fosforilación , Interferencia de ARN , ARN Interferente Pequeño/genética , Transducción de Señal/genética , Células Madre/citología , Factores de Transcripción/metabolismo
4.
J Sports Sci Med ; 18(3): 577-585, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31427881

RESUMEN

Consistent prescriptions for event-specific training of swimmers are lacking, which points to likely differences in training practices and a potential gap between practice and scientific knowledge. This study aimed to analyze the distance-specific training load of elite swimmers, derive a consistent training sessions' description and reflect on the current recommendations for training and recovery. The individual training regimes of 18 elite British swimmers were documented by surveying four swim and two strength and conditioning (S&C) coaches. The annual and weekly training load and content were compared between swimmers competing in sprint, middle and long-distance events. Thematic analysis of the surveys was conducted to identify key codes and general dimensions and to define a unified classification of the swimming and S&C training sessions. Weekly training loads and content of the swim (ƞ2 - effect size; p = 0.016, ƞ2 = 0.423) and S&C (p = 0.028, ƞ2 = 0.38) sessions significantly differed between the groups. Long-distance swimmers swam significantly longer distances (mean ± SD; 58.1 ± 10.2 km vs. 43.2 ± 5.3 km; p = 0.018) weekly but completed similar number of S&C sessions compared to sprinters. The annual swimming load distribution of middle-distance specialists did not differ from that of long-distance swimmers but consisted of more S&C sessions per week (4.7 ± 0.5 vs. 2.3 ± 2.3; p = 0.04). Sprinters and middle-distance swimmers swam similar distances per week and completed similar number of S&C sessions but with different proportional content. Whereas all coaches reported monitoring fatigue, only 51% indicated implementing individualized recovery protocols. We propose a consistent terminology for the description of training sessions in elite swimming to facilitate good practice exchanges. While the training prescription of elite British swimmers conforms to the scientific training principles, recommendations for recovery protocols to reduce the risk of injury and overtraining are warranted.


Asunto(s)
Acondicionamiento Físico Humano/métodos , Natación/fisiología , Terminología como Asunto , Adolescente , Rendimiento Atlético/fisiología , Trastornos de Traumas Acumulados/prevención & control , Femenino , Humanos , Masculino , Fatiga Muscular/fisiología , Acondicionamiento Físico Humano/efectos adversos , Acondicionamiento Físico Humano/clasificación , Entrenamiento de Fuerza , Factores de Riesgo , Natación/lesiones , Reino Unido , Adulto Joven
5.
Lancet ; 385(9976): 1406-17, 2015 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-25542620

RESUMEN

BACKGROUND: Most patients with Crohn's disease need an intestinal resection, but a majority will subsequently experience disease recurrence and require further surgery. This study aimed to identify the optimal strategy to prevent postoperative disease recurrence. METHODS: In this randomised trial, consecutive patients from 17 centres in Australia and New Zealand undergoing intestinal resection of all macroscopic Crohn's disease, with an endoscopically accessible anastomosis, received 3 months of metronidazole therapy. Patients at high risk of recurrence also received a thiopurine, or adalimumab if they were intolerant to thiopurines. Patients were randomly assigned to parallel groups: colonoscopy at 6 months (active care) or no colonoscopy (standard care). We used computer-generated block randomisation to allocate patients in each centre to active or standard care in a 2:1 ratio. For endoscopic recurrence (Rutgeerts score ≥i2) at 6 months, patients stepped-up to thiopurine, fortnightly adalimumab with thiopurine, or weekly adalimumab. The primary endpoint was endoscopic recurrence at 18 months. Patients and treating physicians were aware of the patient's study group and treatment, but central reading of the endoscopic findings was undertaken blind to the study group and treatment. Analysis included all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT00989560. FINDINGS: Between Oct 13, 2009, and Sept 28, 2011, 174 (83% high risk across both active and standard care groups) patients were enrolled and received at least one dose of study drug. Of 122 patients in the active care group, 47 (39%) stepped-up treatment. At 18 months, endoscopic recurrence occurred in 60 (49%) patients in the active care group and 35 (67%) patients in the standard care group (p=0.03). Complete mucosal normality was maintained in 27 (22%) of 122 patients in the active care group versus four (8%) in the standard care group (p=0.03). In the active care arm, of those with 6 months recurrence who stepped up treatment, 18 (38%) of 47 patients were in remission 12 months later; conversely, of those in remission at 6 months who did not change therapy recurrence occurred in 31 (41%) of 75 patients 12 months later. Smoking (odds ratio [OR] 2.4, 95% CI 1.2-4.8, p=0.02) and the presence of two or more clinical risk factors including smoking (OR 2.8, 95% CI 1.01-7.7, p=0.05) increased the risk of endoscopic recurrence. The incidence and type of adverse and severe adverse events did not differ significantly between patients in the active care and standard care groups (100 [82%] of 122 vs 45 [87%] of 52; p=0.51) and (33 [27%] of 122 vs 18 [35%] of 52; p=0.36), respectively. INTERPRETATION: Treatment according to clinical risk of recurrence, with early colonoscopy and treatment step-up for recurrence, is better than conventional drug therapy alone for prevention of postoperative Crohn's disease recurrence. Selective immune suppression, adjusted for early recurrence, rather than routine use, leads to disease control in most patients. Clinical risk factors predict recurrence, but patients at low risk also need monitoring. Early remission does not preclude the need for ongoing monitoring. FUNDING: AbbVie, Gutsy Group, Gandel Philanthropy, Angior Foundation, Crohn's Colitis Australia, and the National Health and Medical Research Council.


Asunto(s)
Enfermedad de Crohn/terapia , Adalimumab , Adulto , Anticuerpos Monoclonales Humanizados/administración & dosificación , Azatioprina/uso terapéutico , Colonoscopía , Enfermedad de Crohn/patología , Enfermedad de Crohn/cirugía , Femenino , Humanos , Masculino , Mercaptopurina/uso terapéutico , Metronidazol/uso terapéutico , Persona de Mediana Edad , Recurrencia , Resultado del Tratamiento
6.
Gastroenterology ; 148(5): 938-947.e1, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25620670

RESUMEN

BACKGROUND & AIMS: Crohn's disease (CD) usually recurs after intestinal resection; postoperative endoscopic monitoring and tailored treatment can reduce the chance of recurrence. We investigated whether monitoring levels of fecal calprotectin (FC) can substitute for endoscopic analysis of the mucosa. METHODS: We analyzed data collected from 135 participants in a prospective, randomized, controlled trial, performed at 17 hospitals in Australia and 1 hospital in New Zealand, that assessed the ability of endoscopic evaluations and step-up treatment to prevent CD recurrence after surgery. Levels of FC, serum levels of C-reactive protein (CRP), and Crohn's disease activity index (CDAI) scores were measured before surgery and then at 6, 12, and 18 months after resection of all macroscopic Crohn's disease. Ileocolonoscopies were performed at 6 months after surgery in 90 patients and at 18 months after surgery in all patients. RESULTS: Levels of FC were measured in 319 samples from 135 patients. The median FC level decreased from 1347 µg/g before surgery to 166 µg/g at 6 months after surgery, but was higher in patients with disease recurrence (based on endoscopic analysis; Rutgeerts score, ≥i2) than in patients in remission (275 vs 72 µg/g, respectively; P < .001). Combined 6- and 18-month levels of FC correlated with the presence (r = 0.42; P < .001) and severity (r = 0.44; P < .001) of CD recurrence, but the CRP level and CDAI score did not. Levels of FC greater than 100 µg/g indicated endoscopic recurrence with 89% sensitivity and 58% specificity, and a negative predictive value (NPV) of 91%; this means that colonoscopy could have been avoided in 47% of patients. Six months after surgery, FC levels less than 51 µg/g in patients in endoscopic remission predicted maintenance of remission (NPV, 79%). In patients with endoscopic recurrence at 6 months who stepped-up treatment, FC levels decreased from 324 µg/g at 6 months to 180 µg/g at 12 months and 109 µg/g at 18 months. CONCLUSIONS: In this analysis of data from a prospective clinical trial, FC measurement has sufficient sensitivity and NPV values to monitor for CD recurrence after intestinal resection. Its predictive value might be used to identify patients most likely to relapse. After treatment for recurrence, the FC level can be used to monitor response to treatment. It predicts which patients will have disease recurrence with greater accuracy than CRP level or CDAI score.


Asunto(s)
Enfermedad de Crohn/cirugía , Heces/química , Complejo de Antígeno L1 de Leucocito/metabolismo , Adulto , Australia , Biomarcadores/metabolismo , Proteína C-Reactiva/metabolismo , Colonoscopía , Enfermedad de Crohn/diagnóstico , Enfermedad de Crohn/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nueva Zelanda , Valor Predictivo de las Pruebas , Estudios Prospectivos , Recurrencia , Inducción de Remisión , Factores de Tiempo , Resultado del Tratamiento
7.
J Strength Cond Res ; 30(11): 3098-3106, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27028155

RESUMEN

Johnston, MJ, Cook, CJ, Drake, D, Costley, L, Johnston, JP, and Kilduff, LP. The neuromuscular, biochemical, and endocrine responses to a single-session vs. double-session training day in elite athletes. J Strength Cond Res 30(11): 3098-3106, 2016-The aim of this study was to compare the acute neuromuscular, biochemical, and endocrine responses of a training day consisting of a speed session only with performing a speed-and-weights training session on the same day. Fifteen men who were academy-level rugby players completed 2 protocols in a randomized order. The speed-only protocol involved performing 6 maximal effort repetitions of 50-m running sprints with 5 minutes of recovery between each sprint, whereas the speed-and-weights protocol involved the same sprinting session but was followed 2 hours later by a lower-body weights session consisting of 4 sets of 5 backsquats and Romanian deadlift at 85% one repetition maximum. Testosterone, cortisol, creatine kinase, lactate, and perceived muscle soreness were determined immediately before, immediately after, 2 hours after, and 24 hours after both the protocols. Peak power, relative peak power, jump height, and average rate of force development were determined from a countermovement jump (CMJ) at the same time points. After 24-hours, muscle soreness was significantly higher after the speed-and-weights protocol compared with the speed-only protocol (effect size η = 0.253, F = 4.750, p ≤ 0.05). There was no significant difference between any of the CMJ variables at any of the posttraining time points. Likewise, creatine kinase, testosterone, and cortisol were unaffected by the addition of a weight-training session. These data indicate that the addition of a weight-training session 2 hours after a speed session, whereas increasing the perception of fatigue the next day does not result in a difference in endocrine response or in neuromuscular capability.


Asunto(s)
Atletas , Acondicionamiento Físico Humano/métodos , Rendimiento Atlético/fisiología , Creatina Quinasa/sangre , Prueba de Esfuerzo , Fútbol Americano/fisiología , Humanos , Hidrocortisona/sangre , Ácido Láctico/sangre , Masculino , Fuerza Muscular/fisiología , Mialgia/fisiopatología , Distribución Aleatoria , Testosterona/sangre , Adulto Joven
8.
J Liposome Res ; 23(2): 101-9, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23294393

RESUMEN

CONTEXT: At elevated temperatures, studies have shown that serum albumin undergoes irreversible changes to its secondary structure. Anionic fatty acids and/or anionic surfactants have been shown to stabilize human serum albumin (HSA) against thermal denaturation through bridging hydrophobic domains and cationic amino acids residues of the protein. OBJECTIVE: As albumin can readily interact with a variety of liposomes, this study proposes that cardiolipin delivered via 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes can improve the thermal stability of recombinant HSA produced in Saccharomyces cerevisiae (ScrHSA) in a similar manner to anionic fatty acids. MATERIALS AND METHODS: Thermal stability and structure of ScrHSA in the absence and presence of DPPC/cardiolipin liposomes was assessed with U/V circular dichroism spectropolarimetry and protein thermal stability was confirmed with differential scanning calorimetry. RESULTS: Although freshly prepared DPPC/cardiolipin liposomes did not improve the stability of ScrHSA, DPPC/cardiolipin liposomes incubated at room temperature for 7 d (7dRT) dramatically improved the thermal stability of the protein. Mass spectrometry analysis identified the presence of fatty acids in the 7dRT liposomes, not identified in freshly prepared liposomes, to which the improved stability was attributed. DISCUSSION AND CONCLUSION: The generation of fatty acids is attributed to either the chemical hydrolysis or oxidative cleavage of the unsaturated acyl chains of cardiolipin. By modulating the lipid composition through the introduction of lipids with higher acyl chain unsaturation, it may be possible to generate the stabilizing fatty acids in a more rapid manner.


Asunto(s)
1,2-Dipalmitoilfosfatidilcolina/análogos & derivados , Cardiolipinas/química , Ácidos Grasos/síntesis química , Liposomas , Albúmina Sérica/química , 1,2-Dipalmitoilfosfatidilcolina/química , Rastreo Diferencial de Calorimetría , Dicroismo Circular , Espectrometría de Masas , Proteínas Recombinantes/química
9.
Front Oncol ; 13: 1221611, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37576901

RESUMEN

Introduction: Medulloblastoma is the most common type of malignant pediatric brain tumor with group 4 medulloblastomas (G4 MBs) accounting for 40% of cases. However, the molecular mechanisms that underlie this subgroup are still poorly understood. Point mutations are detected in a large number of genes at low incidence per gene while the detection of complex structural variants in recurrently affected genes typically requires the application of long-read technologies. Methods: Here, we applied linked-read sequencing, which combines the long-range genome information of long-read sequencing with the high base pair accuracy of short read sequencing and very low sample input requirements. Results: We demonstrate the detection of complex structural variants and point mutations in these tumors, and, for the first time, the detection of extrachromosomal DNA (ecDNA) with linked-reads. We provide further evidence for the high heterogeneity of somatic mutations in G4 MBs and add new complex events associated with it. Discussion: We detected several enhancer-hijacking events, an ecDNA containing the MYCN gene, and rare structural rearrangements, such a chromothripsis in a G4 medulloblastoma, chromoplexy involving 8 different chromosomes, a TERT gene rearrangement, and a PRDM6 duplication.

10.
Vaccines (Basel) ; 11(10)2023 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-37896985

RESUMEN

In recent years, lipid nanoparticles (LNPs) have emerged as a revolutionary technology for vaccine delivery. LNPs serve as an integral component of mRNA vaccines by protecting and transporting the mRNA payload into host cells. Despite their prominence in mRNA vaccines, there remains a notable gap in our understanding of the potential application of LNPs for the delivery of DNA vaccines. In this study, we sought to investigate the suitability of leading LNP formulations for the delivery of plasmid DNA (pDNA). In addition, we aimed to explore key differences in the properties of popular LNP formulations when delivering either mRNA or DNA. To address these questions, we compared three leading LNP formulations encapsulating mRNA- or pDNA-encoding firefly luciferase based on potency, expression kinetics, biodistribution, and immunogenicity. Following intramuscular injection in mice, we determined that RNA-LNPs formulated with either SM-102 or ALC-0315 lipids were the most potent (all p-values < 0.01) and immunogenic (all p-values < 0.05), while DNA-LNPs formulated with SM-102 or ALC-0315 demonstrated the longest duration of signal. Additionally, all LNP formulations were found to induce expression in the liver that was proportional to the signal at the injection site (SM102: r = 0.8787, p < 0.0001; ALC0315: r = 0.9012, p < 0.0001; KC2: r = 0.9343, p < 0.0001). Overall, this study provides important insights into the differences between leading LNP formulations and their applicability to DNA- and RNA-based vaccinations.

11.
PLoS One ; 18(11): e0294406, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38019850

RESUMEN

The importance and fast growth of therapeutic monoclonal antibodies, both innovator and biosimilar products, have triggered the need for the development of characterization methods at high resolution such as nuclear magnetic resonance (NMR) spectroscopy. However, the full power of NMR spectroscopy cannot be unleashed without labelling the mAb of interest with NMR-active isotopes. Here, we present strategies using either Komagataella phaffii (Pichia pastoris) or Escherichia coli that can be widely applied for the production of the antigen-binding fragment (Fab) of therapeutic antibodies of immunoglobulin G1 kappa isotype. The E. coli approach consists of expressing Fab fragments as a single polypeptide chain with a cleavable linker between the heavy and light chain in inclusion bodies, while K. phaffii secretes a properly folded fragment in the culture media. After optimization, the protocol yielded 10-45 mg of single chain adalimumab-Fab, trastuzumab-Fab, rituximab-Fab, and NISTmAb-Fab per liter of culture. Comparison of the 2D-1H-15N-HSQC spectra of each Fab fragment, without their polyhistidine tag and linker, with the corresponding Fab from the innovator product showed that all four fragments have folded into the correct conformation. Production of 2H-13C-15N-adalimumab-scFab and 2H-13C-15N-trastuzumab-scFab (>98% enrichment for all three isotopes) yielded NMR samples where all amide deuterons have completely exchanged back to proton during the refolding procedure.


Asunto(s)
Escherichia coli , Fragmentos Fab de Inmunoglobulinas , Fragmentos Fab de Inmunoglobulinas/genética , Fragmentos Fab de Inmunoglobulinas/química , Escherichia coli/genética , Pichia , Adalimumab/uso terapéutico , Isótopos de Carbono , Anticuerpos Monoclonales , Trastuzumab
12.
Emerg Microbes Infect ; 12(1): 2192821, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36927227

RESUMEN

Influenza and Respiratory Syncytial virus (RSV) infections together contribute significantly to the burden of acute lower respiratory tract infections. Despite the disease burden, no approved RSV vaccine is available. While approved vaccines are available for influenza, seasonal vaccination is required to maintain protection. In addition to both being respiratory viruses, they follow a common seasonality, which warrants the necessity for a concerted vaccination approach. Here, we designed bivalent vaccines by utilizing highly conserved sequences, targeting both influenza A and RSV, as either a chimeric antigen or individual antigens separated by a ribosome skipping sequence. These vaccines were found to be effective in protecting the animals from challenge by either virus, with mechanisms of protection being substantially interrogated in this communication.


Asunto(s)
Vacunas contra la Influenza , Gripe Humana , Infecciones por Virus Sincitial Respiratorio , Ratones , Animales , Humanos , Virus Sincitiales Respiratorios/genética , Vacunas Combinadas , Anticuerpos Antivirales , Infecciones por Virus Sincitial Respiratorio/prevención & control , Vacunas contra la Influenza/genética , Anticuerpos Neutralizantes
13.
Front Immunol ; 14: 1020134, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37006299

RESUMEN

Introduction: The incidence of Lyme disease (LD) in Canada and the United States has risen over the last decade, nearing 480,000 cases each year. Borrelia burgdorferi sensu lato, the causative agent of LD, is transmitted to humans through the bite of an infected tick, resulting in flu-like symptoms and often a characteristic bull's-eye rash. In more severe cases, disseminated bacterial infection can cause arthritis, carditis and neurological impairments. Currently, no vaccine is available for the prevention of LD in humans. Methods: In this study, we developed a lipid nanoparticle (LNP)-encapsulated DNA vaccine encoding outer surface protein C type A (OspC-type A) of B. burgdorferi. Results: Vaccination of C3H/HeN mice with two doses of the candidate vaccine induced significant OspC-type A-specific antibody titres and borreliacidal activity. Analysis of the bacterial burden following needle challenge with B. burgdorferi (OspC-type A) revealed that the candidate vaccine afforded effective protection against homologous infection across a range of susceptible tissues. Notably, vaccinated mice were protected against carditis and lymphadenopathy associated with Lyme borreliosis. Discussion: Overall, the results of this study provide support for the use of a DNA-LNP platform for the development of LD vaccines.


Asunto(s)
Borrelia burgdorferi , Enfermedad de Lyme , Miocarditis , Vacunas de ADN , Humanos , Ratones , Animales , Vacunas Bacterianas , Ratones Endogámicos C3H , ADN
14.
Nat Commun ; 14(1): 3062, 2023 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-37244935

RESUMEN

Self-renewal is a crucial property of glioblastoma cells that is enabled by the choreographed functions of chromatin regulators and transcription factors. Identifying targetable epigenetic mechanisms of self-renewal could therefore represent an important step toward developing effective treatments for this universally lethal cancer. Here we uncover an epigenetic axis of self-renewal mediated by the histone variant macroH2A2. With omics and functional assays deploying patient-derived in vitro and in vivo models, we show that macroH2A2 shapes chromatin accessibility at enhancer elements to antagonize transcriptional programs of self-renewal. macroH2A2 also sensitizes cells to small molecule-mediated cell death via activation of a viral mimicry response. Consistent with these results, our analyses of clinical cohorts indicate that high transcriptional levels of this histone variant are associated with better prognosis of high-grade glioma patients. Our results reveal a targetable epigenetic mechanism of self-renewal controlled by macroH2A2 and suggest additional treatment approaches for glioblastoma patients.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Humanos , Histonas/genética , Histonas/metabolismo , Glioblastoma/metabolismo , Regulación Neoplásica de la Expresión Génica , Cromatina/metabolismo , Epigénesis Genética , Línea Celular Tumoral , Células Madre Neoplásicas/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo
15.
bioRxiv ; 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38116029

RESUMEN

Polycomb Repressive Complex 2 (PRC2)-mediated histone H3K27 tri-methylation (H3K27me3) recruits canonical PRC1 (cPRC1) to maintain heterochromatin. In early development, polycomb-regulated genes are connected through long-range 3D interactions which resolve upon differentiation. Here, we report that polycomb looping is controlled by H3K27me3 spreading and regulates target gene silencing and cell fate specification. Using glioma-derived H3 Lys-27-Met (H3K27M) mutations as tools to restrict H3K27me3 deposition, we show that H3K27me3 confinement concentrates the chromatin pool of cPRC1, resulting in heightened 3D interactions mirroring chromatin architecture of pluripotency, and stringent gene repression that maintains cells in progenitor states to facilitate tumor development. Conversely, H3K27me3 spread in pluripotent stem cells, following neural differentiation or loss of the H3K36 methyltransferase NSD1, dilutes cPRC1 concentration and dissolves polycomb loops. These results identify the regulatory principles and disease implications of polycomb looping and nominate histone modification-guided distribution of reader complexes as an important mechanism for nuclear compartment organization. Highlights: The confinement of H3K27me3 at PRC2 nucleation sites without its spreading correlates with increased 3D chromatin interactions.The H3K27M oncohistone concentrates canonical PRC1 that anchors chromatin loop interactions in gliomas, silencing developmental programs.Stem and progenitor cells require factors promoting H3K27me3 confinement, including H3K36me2, to maintain cPRC1 loop architecture.The cPRC1-H3K27me3 interaction is a targetable driver of aberrant self-renewal in tumor cells.

16.
J Pathol ; 224(4): 461-72, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21465486

RESUMEN

Transforming growth factor ß (TGF-ß) is known to play a key role in intestinal fibrosis; however, the underlying mechanisms are not well understood. TGF-ß signal transduction is through TGF-ß receptors, including the TGF-ß type 1 receptor. Most cell types contain a TGF-ß type 1 receptor form known as activin receptor-like kinase 5 (ALK5), which propagates the signal to the nucleus through the phosphorylation of Smad2 and Smad3 proteins. Therefore, we assessed the effect of the disruption of TGF-ß/ALK5/Smad signalling by an ALK5 inhibitor (SD-208) in two experimental animal models of intestinal fibrosis: anaerobic bacteria- and trinitrobenzensulphonic acid-induced colitis. In addition, isolated myofibroblasts were pretreated with SD-208 and exposed to recombinant TGF-ß1. Finally, myofibroblasts were transfected with ALK5, Smad2, and Smad3-specific siRNA. Up-regulation of ALK5 and TIMP-1, phosphorylation of Smad2 and Smad3 proteins, and increased intestinal wall collagen deposition were found in both experimental animal models. These effects were decreased by SD-208. TGF-ß1 treatment also induced phosphorylation of Smad2 and Smad3 and up-regulation of ALK5 protein, TIMP-1, and α2 type 1 collagen gene expression in isolated myofibroblasts. Again these effects were inhibited by SD-208. Also, ALK5, Smad2, and Smad3 siRNA abolished the induction of TIMP-1 and α2 type 1 collagen. Our findings provide evidence that the TGF-ß/ALK5/Smad pathway participates in the pathogenesis of experimental intestinal fibrosis. These data show promise for the development of an effective therapeutic intervention in this condition.


Asunto(s)
Colitis/metabolismo , Colágeno/biosíntesis , Proteínas Serina-Treonina Quinasas/fisiología , Receptores de Factores de Crecimiento Transformadores beta/fisiología , Proteínas Smad/fisiología , Inhibidor Tisular de Metaloproteinasa-1/biosíntesis , Animales , Bacterias Anaerobias , Infecciones Bacterianas/metabolismo , Infecciones Bacterianas/patología , Células Cultivadas , Colitis/etiología , Colitis/patología , Colon/metabolismo , Colon/patología , Modelos Animales de Enfermedad , Fibrosis , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Masculino , Miofibroblastos/metabolismo , Miofibroblastos/patología , Ratas , Ratas Sprague-Dawley , Receptor Tipo I de Factor de Crecimiento Transformador beta , Trinitrobencenos/farmacología
17.
Artículo en Inglés | MEDLINE | ID: mdl-34819303

RESUMEN

B-cell acute lymphoblastic leukemia (B-ALL) is often driven by chromosome translocations that result in recurrent and well-studied gene fusions. Currently, fluorescent in situ hybridization probes are used to detect candidate translocations in bone marrow samples from B-ALL patients. Recently Hi-C, a sequencing-based technique originally designed to reconstruct the three-dimensional architecture of the nuclear genome, was shown to effectively recognize structural variants. Here, we demonstrate that Hi-C can be used as a genome-wide assay to detect translocations and other structural variants of potential clinical interest. Structural variants were identified in both bone marrow and peripheral blood samples, including an ETV6-RUNX1 translocation present in one pediatric B-ALL patient. Our report provides proof of principle that Hi-C could be an effective strategy to globally detect driver structural variants in B-ALL peripheral blood specimens, reducing the need for invasive bone marrow biopsies and candidate-based clinical tests.


Asunto(s)
Proteínas de Fusión Oncogénica , Leucemia-Linfoma Linfoblástico de Células Precursoras , Niño , Variación Estructural del Genoma , Humanos , Hibridación Fluorescente in Situ , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Translocación Genética/genética
18.
Gastroenterology ; 138(4): 1395-405, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20044996

RESUMEN

BACKGROUND & AIMS: Infection with the rat tapeworm Hymenolepis diminuta reduces the severity of dinitrobenzene sulfonic acid (DNBS)-induced colitis in mice. Infection with H. diminuta increases colonic expression of arginase-1 and found in inflammatory zone 1 (FIZZ1), markers of alternatively activated macrophages (AAMs). We investigated whether AAMs have anticolitic effects. METHODS: Normal or macrophage-depleted Balb/c mice were infected with H. diminuta; some mice were given DNBS, and the severity of colitis was assessed by disease activity scores, myeloperoxidase activity, and histologic examination. AAMs were also differentiated in vitro, given to mice by intraperitoneal or intravenous injection, and the effects on DNBS-induced colitis were determined. Numbers of AAMs were assessed in biopsy specimens from patients with Crohn's disease. RESULTS: Depletion of intestinal macrophages using clodronate-liposomes prevented the anticolitic effect of infection with H. diminuta. Injection of AAMs, but not classically activated macrophages, significantly reduced the severity of DNBS-induced colitis. The AAM-induced, anticolitic effect was accompanied by increased interleukin (IL)-10 production from mitogen-stimulated spleen cells; in vivo neutralization of IL-10 partially reduced the effects of AAM transfer. Patients with active CD had reduced numbers of CD68(+)CD206(+) macrophages (which indicate AAM), whereas biopsy specimens from patients with inactive CD had increased numbers of these cells. CONCLUSIONS: Analysis of the H. diminuta-murine DNBS system identified the AAM, which, when administered to mice, significantly reduced DNBS-induced colitis. The ability to derive AAMs from patients' blood suggests that adoptive transfer of these cells could be a novel approach to inflammatory bowel disease.


Asunto(s)
Colitis/prevención & control , Activación de Macrófagos , Macrófagos/fisiología , Animales , Arginasa/genética , Bencenosulfonatos , Humanos , Himenolepiasis/inmunología , Hymenolepis diminuta , Péptidos y Proteínas de Señalización Intercelular/genética , Interleucina-10/biosíntesis , Masculino , Ratones , Ratones Endogámicos BALB C , Neutrófilos/fisiología
19.
Int J Sports Physiol Perform ; 16(12): 1758-1763, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34039769

RESUMEN

PURPOSE: To compare resistance training using a velocity loss threshold with training to repetition failure on upper-body strength parameters in professional Australian footballers. METHODS: A total of 26 professional Australian footballers (23.9 [4.2] y, 189.9 [7.8] cm, 88.2 [8.8] kg) tested 1-repetition-maximum strength (FPmax) and mean barbell velocity at 85% of 1-repetition maximum on floor press (FPvel). They were then assigned to 2 training groups: 20% velocity loss threshold training (VL; n = 12, maximum-effort lift velocity) or training to repetition failure (TF; n = 14, self-selected lift velocity). Subjects trained twice per week for 3 weeks before being reassessed on FPmax and FPvel. Training volume (total repetitions) was recorded for all training sessions. No differences were present between groups on any pretraining measure. RESULTS: The TF group significantly improved FPmax (105.2-110.9 kg, +5.4%), while the VL group did not (107.5-109.2 kg, +1.6%) (P > .05). Both groups significantly increased FPvel (0.38-0.46 m·s-1, +19.1% and 0.37-0.42 m·s-1, +16.7%, respectively) with no between-groups differences evident (P > .05). The TF group performed significantly more training volume (12.2 vs 6.8 repetitions per session, P > .05). CONCLUSIONS: Training to repetition failure improved FPmax, while training using a velocity loss threshold of 20% did not. Both groups demonstrated similar improvements in FPvel despite the VL group completing 45% less total training volume than the TF group. The reduction in training volume associated with implementing a 20% velocity loss threshold may negatively impact the development of upper-body maximum strength while still enhancing submaximal movement velocity.


Asunto(s)
Fuerza Muscular , Entrenamiento de Fuerza , Australia , Humanos , Músculo Esquelético
20.
Sci Rep ; 11(1): 4768, 2021 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-33637809

RESUMEN

The development of reference standards for nanoparticle sizing allows for cross laboratory studies and effective transfer of particle sizing methodology. To facilitate this, these reference standards must be stable upon long-term storage. Here, we examine factors that influence the properties of cross-linked albumin nanoparticles, fabricated with an ethanol desolvation method, when reconstituted from a lyophilized state. We demonstrate, with nanoparticle tracking analysis, no significant changes in mean particle diameter upon reconstitution of albumin nanoparticles fabricated with bovine serum albumin loaded with dodecanoic acid, when compared to nanoparticles fabricated with a fatty acid-free BSA. We attribute this stability to the modulation of nanoparticle charge-charge interactions at dodecanoic acid specific binding locations. Furthermore, we demonstrate this in a lyophilized state over six months when stored at - 80 °C. We also show that the reconstitution process is readily transferable between technicians and laboratories and further confirm our finding with dynamic light scattering analysis.

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