Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Biotechniques ; 74(5): 211-224, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37161298

RESUMO

Designed donor DNA delivery through viral or nonviral systems to target loci in the host genome is a critical step for gene therapy. Adeno-associated virus and lentivirus are leading vehicles for in vivo and ex vivo delivery of therapeutic genes due to their high delivery and editing efficiency. Nonviral editing tools, such as CRISPR/Cas9, are getting more attention for gene modification. However, there are safety concerns; for example, tumorigenesis due to off-target effects and DNA rearrangement. Analysis tools to detect and characterize on-target and off-target genome modification post editing in the host genome are pivotal for evaluating the success and safety of gene therapy. We developed Target-seq combined with different analysis tools to detect the genome integration site, DNA translocation and off-target events.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Sistemas CRISPR-Cas/genética , Fluxo de Trabalho , Terapia Genética , DNA/genética
2.
J Neuroinflammation ; 20(1): 5, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36609298

RESUMO

BACKGROUND: In response to brain injury or inflammation, astrocytes undergo hypertrophy, proliferate, and migrate to the damaged zone. These changes, collectively known as "astrogliosis", initially protect the brain; however, astrogliosis can also cause neuronal dysfunction. Additionally, these astrocytes undergo intracellular changes involving alterations in the expression and localization of many proteins, including αvß3 integrin. Our previous reports indicate that Thy-1, a neuronal glycoprotein, binds to this integrin inducing Connexin43 (Cx43) hemichannel (HC) opening, ATP release, and astrocyte migration. Despite such insight, important links and molecular events leading to astrogliosis remain to be defined. METHODS: Using bioinformatics approaches, we analyzed different Gene Expression Omnibus datasets to identify changes occurring in reactive astrocytes as compared to astrocytes from the normal mouse brain. In silico analysis was validated by both qRT-PCR and immunoblotting using reactive astrocyte cultures from the normal rat brain treated with TNF and from the brain of a hSOD1G93A transgenic mouse model. We evaluated the phosphorylation of Cx43 serine residue 373 (S373) by AKT and ATP release as a functional assay for HC opening. In vivo experiments were also performed with an AKT inhibitor (AKTi). RESULTS: The bioinformatics analysis revealed that genes of the PI3K/AKT signaling pathway were among the most significantly altered in reactive astrocytes. mRNA and protein levels of PI3K, AKT, as well as Cx43, were elevated in reactive astrocytes from normal rats and from hSOD1G93A transgenic mice, as compared to controls. In vitro, reactive astrocytes stimulated with Thy-1 responded by activating AKT, which phosphorylated S373Cx43. Increased pS373Cx43 augmented the release of ATP to the extracellular medium and AKTi inhibited these Thy-1-induced responses. Furthermore, in an in vivo model of inflammation (brain damage), AKTi decreased the levels of astrocyte reactivity markers and S373Cx43 phosphorylation. CONCLUSIONS: Here, we identify changes in the PI3K/AKT molecular signaling network and show how they participate in astrogliosis by regulating the HC protein Cx43. Moreover, because HC opening and ATP release are important in astrocyte reactivity, the phosphorylation of Cx43 by AKT and the associated increase in ATP release identify a potential therapeutic window of opportunity to limit the adverse effects of astrogliosis.


Assuntos
Lesões Encefálicas , Conexina 43 , Animais , Camundongos , Ratos , Trifosfato de Adenosina/farmacologia , Trifosfato de Adenosina/metabolismo , Astrócitos/metabolismo , Lesões Encefálicas/metabolismo , Conexina 43/metabolismo , Gliose/metabolismo , Inflamação/metabolismo , Integrina beta3/genética , Integrina beta3/metabolismo , Integrina beta3/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Regulação para Cima , Antígenos Thy-1/metabolismo , Integrina alfa5/metabolismo
3.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1421729

RESUMO

Extracapsular dissection is an old technique use for the removal of benign parotid tumours, which is not generally chosen as the first treatment option due to the association of recurrences in the past but is currently considered again accord to the aesthetic requirements of the patients. The general trend in the last decade is to return to minimally invasive procedures for this type of lesions, which are mainly conditioned by the pleomorphic adenoma and its positive margins in its capsule. By this, the purpose of this case series study is to analyze those patients diagnosed with benign parotid tumors and treated by extracapsular dissection in a tertiary hospital in Chile between 2018-2020.

4.
J Immunother Cancer ; 10(7)2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35882447

RESUMO

BACKGROUND: The correlation between elevated T-cell infiltration and improved survival of ovarian cancer (OvCa) patients suggests that endogenous tumor-infiltrating lymphocytes (TIL) possess some degree of antitumor activity that can be harnessed for OvCa immunotherapy. We previously optimized a protocol for ex vivo OvCa TIL expansion for adoptive cell therapy, which is now being tested in a clinical trial at our institution (NCT03610490). Building on this success, we embarked on genetic modification of OvCa TIL to overcome key immunosuppressive factors present in the tumor microenvironment. Here, we present the preclinical optimization of CRISPR/Cas9-mediated knockout of the TGF-ß receptor 2 (TGFBR2) in patient-derived OvCa TIL. METHODS: OvCa TILs were generated from four patients' tumor samples obtained at surgical resection and subjected to CRISPR/Cas9-mediated knockout of TGFBR2 before undergoing a rapid expansion protocol. TGFBR2-directed gRNAs were comprehensively evaluated for their TGFBR2 knockout efficiency and off-target activity. Furthermore, the impact of TGFBR2 knockout on TIL expansion, function, and downstream signaling was assayed. RESULTS: TGFBR2 knockout efficiencies ranging from 59±6% to 100%±0% were achieved using 5 gRNAs tested in four independent OvCa TIL samples. TGFBR2 knockout TIL were resistant to immunosuppressive TGF-ß signaling as evidenced by a lack of SMAD phosphorylation, a lack of global transcriptional changes in response to TGF-ß stimulation, equally strong secretion of proinflammatory cytokines in the presence and absence of TGF-ß, and improved cytotoxicity in the presence of TGF-ß. CRISPR-modification itself did not alter the ex vivo expansion efficiency, immunophenotype, nor the TCR clonal diversity of OvCa TIL. Importantly for clinical translation, comprehensive analysis of CRISPR off-target effects revealed no evidence of off-target activity for our top two TGFBR2-targeting gRNAs. CONCLUSIONS: CRISPR/Cas9-mediated gene knockout is feasible and efficient in patient-derived OvCa TIL using clinically-scalable methods. We achieved efficient and specific TGFBR2 knockout, yielding an expanded OvCa TIL product that was resistant to the immunosuppressive effects of TGF-ß. This study lays the groundwork for clinical translation of CRISPR-modified TIL, providing opportunities for engineering more potent TIL therapies not only for OvCa treatment, but for the treatment of other solid cancers as well.


Assuntos
Linfócitos do Interstício Tumoral , Neoplasias Ovarianas , Carcinoma Epitelial do Ovário/patologia , Feminino , Humanos , Imunoterapia Adotiva/métodos , Linfócitos do Interstício Tumoral/patologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/terapia , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Fator de Crescimento Transformador beta/genética , Microambiente Tumoral
5.
J Biomed Mater Res B Appl Biomater ; 110(5): 1113-1119, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34894062

RESUMO

Crosslinking substantially reduces the wear of ultra-high molecular weight polyethylene (UHMWPE) used in total hip arthroplasty (THA) but some reports have indicated that first generation liners manufactured without antioxidants may be vulnerable to in vivo oxidation. This study evaluated maximum oxidation using Fourier transform infrared spectroscopy per ASTM F2102-06ε1 and linear head penetration using a coordinate measuring machine among 66 revision-retrieved THA components with in vivo durations ranging from 0.02 to 24.6 years. These included 30 liners crosslinked with 5 Mrad of gamma radiation and then melted, 13 non-crosslinked, never-irradiated liners sterilized with gas plasma and 23 non-crosslinked, never-irradiated liners sterilized with ethylene oxide. All liners were vacuum-sealed and stored at -20°C prior to analysis with the exception of three retrievals of each material type that were stored in air for 9.9 to 21.5 years. All 57 vacuum-sealed and frozen retrievals demonstrated good oxidative stability with maximum oxidation indices (OIs) less than 1.0 and 75% (43/57) of these liners had maximum OIs less than 0.1. Linear penetration measurements were lower in the crosslinked liners compared to non-crosslinked retrievals. Although instances of oxidation and embrittlement were found after ex vivo storage in air among liners that did not have free radicals at the time of implantation, in vivo oxidation does not appear to be a clinical concern through the first decade of service for crosslinked liners and at up to 25 years after surgery for non-crosslinked liners.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Radicais Livres , Humanos , Polietileno/química , Polietilenos/química , Desenho de Prótese , Falha de Prótese , Reoperação
6.
Mol Ecol ; 30(20): 5064-5079, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34379848

RESUMO

Anthropogenic climate change threatens corals globally and both high and low temperatures are known to induce coral bleaching. However, coral stress responses across wide thermal breadths remain understudied. Disentangling the role of symbiosis on the stress response in obligately symbiotic corals is challenging because this response is inherently coupled with nutritional stress. Here, we leverage aposymbiotic colonies of the facultatively symbiotic coral, Astrangia poculata, which lives naturally with and without its algal symbionts, to examine how broad thermal challenges influence coral hosts in the absence of symbiosis. A. poculata were collected from their northern range limit and thermally challenged in two independent 16-day common garden experiments (heat and cold challenge) and behavioural responses to food stimuli and genome-wide gene expression profiling (TagSeq) were performed. Both thermal challenges elicited significant reductions in polyp extension. However, there were five times as many differentially expressed genes (DEGs) under cold challenge compared to heat challenge. Despite an overall stronger response to cold challenge, there was significant overlap in DEGs between thermal challenges. We contrasted these responses to a previously identified module of genes associated with the environmental stress response (ESR) in tropical reef-building corals. Cold challenged corals exhibited a pattern consistent with more severe stressors while the heat challenge response was consistent with lower intensity stressors. Given that these responses were observed in aposymbiotic colonies, many genes previously implicated in ESRs in tropical symbiotic species may represent the coral host's stress response in or out of symbiosis.


Assuntos
Antozoários , Recifes de Corais , Animais , Antozoários/genética , Temperatura Alta , Estresse Fisiológico , Simbiose
7.
Cell Signal ; 83: 109978, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33722671

RESUMO

In the normal heart, cardiac fibroblasts (CFs) maintain extracellular matrix (ECM) homeostasis, whereas in pathological conditions, such as diabetes mellitus (DM), CFs converse into cardiac myofibroblasts (CMFs) and this CFs phenoconversion increase the synthesis and secretion of ECM proteins, promoting cardiac fibrosis and heart dysfunction. High glucose (HG) conditions increase TGF-ß1 expression and FoxO1 activity, whereas FoxO1 is crucial to CFs phenoconversion induced by TGF-ß1. In addition, FoxO1 increases CTGF expression, whereas CTGF plays an active role in the fibrotic process induced by hyperglycemia. However, the role of FoxO1 and CTGF in CFs phenoconversion induced by HG is not clear. In this study, we investigated the effects of FoxO1 pharmacological inhibition on CFs phenoconversion in both in vitro and ex vivo models of DM. Our results demonstrate that HG induces CFs phenoconversion and FoxO1 activation. Moreover, AS1842856, a pharmacological inhibitor of FoxO1 activity, prevents CFs phenoconversion and CTGF expression increase induced by HG, whereas these results were corroborated by FoxO1 silencing. Additionally, K252a, a pharmacological blocker of CTGF receptor, prevents HG-induced CFs phenoconversion, which was corroborated with CTGF expression knockdown. Furthermore, through CFs isolation from heart of diabetic rats, we showed that hyperglycemia induces FoxO1 activation, the increase of CTGF expression and CFs phenoconversion, whereas the FoxO1 activity inhibition reverses the effects induced by hyperglycemia on CFs. Altogether, our results demonstrate that FoxO1 and CTGF are necessary for CFs phenoconversion induced by HG and suggest that both proteins are likely to become a potential targeted drug for fibrotic response induced by hyperglycemic conditions.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Glucose/farmacologia , Miocárdio/metabolismo , Miofibroblastos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Diferenciação Celular/genética , Proteínas do Tecido Nervoso/genética , Ratos , Ratos Sprague-Dawley
8.
J Biol Chem ; 294(18): 7269-7282, 2019 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-30872402

RESUMO

Myoglobin is a monomeric heme protein expressed ubiquitously in skeletal and cardiac muscle and is traditionally considered to function as an oxygen reservoir for mitochondria during hypoxia. It is now well established that low concentrations of myoglobin are aberrantly expressed in a significant proportion of breast cancer tumors. Despite being expressed only at low levels in these tumors, myoglobin is associated with attenuated tumor growth and a better prognosis in breast cancer patients, but the mechanism of this myoglobin-mediated protection against further cancer growth remains unclear. Herein, we report a signaling pathway by which myoglobin regulates mitochondrial dynamics and thereby decreases cell proliferation. We demonstrate in vitro that expression of human myoglobin in MDA-MB-231, MDA-MB-468, and MCF7 breast cancer cells induces mitochondrial hyperfusion by up-regulating mitofusins 1 and 2, the predominant catalysts of mitochondrial fusion. This hyperfusion causes cell cycle arrest and subsequent inhibition of cell proliferation. Mechanistically, increased mitofusin expression was due to myoglobin-dependent free-radical production, leading to the oxidation and degradation of the E3 ubiquitin ligase parkin. We recapitulated this pathway in a murine model in which myoglobin-expressing xenografts exhibited decreased tumor volume with increased mitofusin, markers of cell cycle arrest, and decreased parkin expression. Furthermore, in human triple-negative breast tumor tissues, mitofusin and myoglobin levels were positively correlated. Collectively, these results elucidate a new function for myoglobin as a modulator of mitochondrial dynamics and reveal a novel pathway by which myoglobin decreases breast cancer cell proliferation and tumor growth by up-regulating mitofusin levels.


Assuntos
Neoplasias da Mama/patologia , Proliferação de Células/fisiologia , Dinâmica Mitocondrial/fisiologia , Mioglobina/fisiologia , Animais , Linhagem Celular Tumoral , Feminino , Fase G1/fisiologia , GTP Fosfo-Hidrolases/metabolismo , Xenoenxertos , Humanos , Camundongos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Oxirredução , Fase S/fisiologia , Ubiquitina-Proteína Ligases/metabolismo
9.
Rev Med Chil ; 146(7): 899-906, 2018 Jul.
Artigo em Espanhol | MEDLINE | ID: mdl-30534890

RESUMO

This review examines the evidence about the relationship between dental procedures and the incidence of transient bacteremia. One of the main obstacles was to define "invasive dental procedure" as an indication for antimicrobial prophylaxis for patients with high risk of bacteremia. A search in WorldWideScience and ScienceDirect was performed and 20 articles were selected for review. Two contradictions stood out. There is no concrete evidence that a transient bacteremia arising during a dental procedure may be a risk factor for the appearance of bacterial endocarditis. There is no certainty about the effectiveness of antimicrobial prophylaxis, due to the lack of clinical trials of good quality. There is a similitude between bacteremia resulting from invasive and non-invasive dental procedures. The importance of periodontal health as a preventive measure for bacterial endocarditis among high risk patients is highlighted.


Assuntos
Antibacterianos/uso terapêutico , Anti-Infecciosos/uso terapêutico , Antibioticoprofilaxia , Bacteriemia/prevenção & controle , Endocardite Bacteriana/prevenção & controle , Procedimentos Cirúrgicos Bucais/efeitos adversos , Bacteriemia/etiologia , Assistência Odontológica , Endocardite Bacteriana/etiologia , Medicina Baseada em Evidências , Humanos , Fatores de Risco
10.
Rev. méd. Chile ; 146(7): 899-906, jul. 2018. graf
Artigo em Espanhol | LILACS | ID: biblio-961476

RESUMO

This review examines the evidence about the relationship between dental procedures and the incidence of transient bacteremia. One of the main obstacles was to define "invasive dental procedure" as an indication for antimicrobial prophylaxis for patients with high risk of bacteremia. A search in WorldWideScience and ScienceDirect was performed and 20 articles were selected for review. Two contradictions stood out. There is no concrete evidence that a transient bacteremia arising during a dental procedure may be a risk factor for the appearance of bacterial endocarditis. There is no certainty about the effectiveness of antimicrobial prophylaxis, due to the lack of clinical trials of good quality. There is a similitude between bacteremia resulting from invasive and non-invasive dental procedures. The importance of periodontal health as a preventive measure for bacterial endocarditis among high risk patients is highlighted.


Assuntos
Humanos , Bacteriemia/prevenção & controle , Antibioticoprofilaxia , Procedimentos Cirúrgicos Bucais/efeitos adversos , Endocardite Bacteriana/prevenção & controle , Anti-Infecciosos/uso terapêutico , Antibacterianos/uso terapêutico , Fatores de Risco , Assistência Odontológica , Bacteriemia/etiologia , Medicina Baseada em Evidências , Endocardite Bacteriana/etiologia
11.
ACS Nano ; 12(4): 3689-3698, 2018 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-29537819

RESUMO

Materials that retain a high conductivity under strain are essential for wearable electronics. This article describes a conductive, stretchable composite consisting of a Cu-Ag core-shell nanowire felt infiltrated with a silicone elastomer. This composite exhibits a retention of conductivity under strain that is superior to any composite with a conductivity greater than 1000 S cm-1. This work also shows how the mechanical properties, conductivity, and deformation mechanism of the composite changes as a function of the stiffness of the silicone matrix. The retention of conductivity under strain was found to decrease as the Young's modulus of the matrix increased. This was attributed to void formation as a result of debonding between the nanowire felt and the elastomer. The nanowire composite was also patterned to create serpentine circuits with a stretchability of 300%.

12.
Cell Host Microbe ; 22(4): 543-551.e4, 2017 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-28943328

RESUMO

Humans do not usually develop effective immunity to Staphylococcus aureus reinfection. Using a murine model that mimics human infection, we show that lack of protective immunity to S. aureus systemic reinfection is associated with robust interleukin-10 (IL-10) production and impaired protective Th17 responses. In dendritic cell co-culture assays, priming with S. aureus promotes robust T cell proliferation, but limits Th cells polarization and production of IL-1ß and other cytokines important for Th1 and Th17 differentiation. We show that O-acetylation of peptidoglycan, a mechanism utilized by S. aureus to block bacterial cell wall breakdown, limits the induction of pro-inflammatory signals required for optimal Th17 polarization. IL-10 deficiency in mice restores protective immunity to S. aureus infection, and adjuvancy with a staphylococcal peptidoglycan O-acetyltransferase mutant reduces IL-10, increases IL-1ß, and promotes development of IL-17-dependent, Th cell-transferable protective immunity. Overall, our study suggests a mechanism whereby S. aureus modulates cytokines critical for induction of protective Th17 immunity.


Assuntos
Acetiltransferases/imunologia , Peptidoglicano/imunologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/imunologia , Células Th17/imunologia , Acetilação , Acetiltransferases/metabolismo , Imunidade Adaptativa , Animais , Técnicas de Cocultura , Células Dendríticas/imunologia , Feminino , Humanos , Interleucina-10/imunologia , Interleucina-1beta/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Peptidoglicano/metabolismo
13.
Cell ; 166(3): 624-636, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27374331

RESUMO

Degradation of Gram-positive bacterial cell wall peptidoglycan in macrophage and dendritic cell phagosomes leads to activation of the NLRP3 inflammasome, a cytosolic complex that regulates processing and secretion of interleukin (IL)-1ß and IL-18. While many inflammatory responses to peptidoglycan are mediated by detection of its muramyl dipeptide component in the cytosol by NOD2, we report here that NLRP3 inflammasome activation is caused by release of N-acetylglucosamine that is detected in the cytosol by the glycolytic enzyme hexokinase. Inhibition of hexokinase by N-acetylglucosamine causes its dissociation from mitochondria outer membranes, and we found that this is sufficient to activate the NLRP3 inflammasome. In addition, we observed that glycolytic inhibitors and metabolic conditions affecting hexokinase function and localization induce inflammasome activation. While previous studies have demonstrated that signaling by pattern recognition receptors can regulate metabolic processes, this study shows that a metabolic enzyme can act as a pattern recognition receptor. PAPERCLIP.


Assuntos
Hexoquinase/metabolismo , Inflamassomos/metabolismo , Peptidoglicano/metabolismo , Receptores Imunológicos/metabolismo , Acetilação , Acetilglucosamina/metabolismo , Animais , Bacillus anthracis/metabolismo , Parede Celular/metabolismo , Células Dendríticas/metabolismo , Glicólise , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Modelos Biológicos , Monócitos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Potássio/metabolismo
14.
Odontol. vital ; jun. 2016.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1506851

RESUMO

La osteonecrosis mandibular relacionada con medicamentos (ONMRM), es un síndrome asociado al uso de fármacos antirresortivos (bifosfonatos), inhibidores de ligando RANK-L y de angiogénesis, administrados para el tratamiento de enfermedades como cáncer y osteoporosis. Objetivos: actualizar contenidos respecto a etiopatogenia y tratamientos de ONMRM, enfatizando el rol del factor "infección", y en la perspectiva de que el tratamiento, pueda ser implementado por el odontólogo general. Materiales y métodos: se realiza un scoping review mediante acceso a las bases de datos MEDLINE (Pubmed) y Cochrane library, de artículos publicados desde el año 2010 en adelante, en inglés y castellano, empleando palabras claves incluidas en los medical subject headings (MeSH). Conclusiones: La evidencia recogida demuestra que, teniendo en cuenta los factores de riesgo individuales, no existen en general contraindicaciones para llevar a cabo exodoncias, bajo específicos protocolos quirúrgicos, en pacientes con terapias antiresortivas o antiangiogénicas, ya que al parecer, el origen de la ONMRM se asocia a contaminación por biofilm, más que al uso o efecto de estos fármacos. En el caso del tratamiento de una ONMRM ya instalada, las terapias quirúrgicas resultan ser más eficaces que las paliativas en la remisión del cuadro.


Medication-related osteonecrosis of the jaw (MRONJ) is a syndrome associated to the use of antiresorptive therapy (bisphosphonates), RANK-ligand inhibitors and angiogenesis inhibitors drugs, used for the treatment of cancer and osteoporosis among other diseases. Purpose: Update the knowledge on its etiopathogenesis emphasizing the role of infection, and in doing so, look for treatments that can be carried out by general practitioners. Materials and methods: A scoping review is performed through Medline (Pubmed) and Cochrane databases, of articles published from to 2010, in English and Spanish, including MeSH keywords such as "osteonecrosis of the jaw; "antiresorptive drug"; "bisphosphonates"; "Denosumab"; "surgical wound infection"; "dental extraction". Conclusions: The current evidence demonstrate that, taking into account individual risk factors, teeth extractions can be harmless performed in patients under antiresorptive or antiangiogenic interetherapies because the origin of MRONJ appears to be more related to biofilm contamination than with the use or effects of any specific drug. Once MRONJ is installed, surgical therapies prove to be more effective in the treatment and remission of these lesions.

15.
Adv Mater ; 27(32): 4725-31, 2015 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-26179877

RESUMO

A dynamically adjustable colloidal assembly technique is presented, which combines magnetic and acoustic fields to produce a wide range of colloidal structures, ranging from discrete colloidal molecules, to polymer networks and crystals. The structures can be stabilized and dried, making them suitable for the fabrication of advanced materials.


Assuntos
Acústica , Coloides/química , Campos Magnéticos , Polímeros/química , Cristalização
16.
J Arthroplasty ; 30(10): 1828-34, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26048729

RESUMO

The development of highly cross-linked UHMWPEs focused on stabilizing radiation-induced free radicals as the sole precursor to oxidative degradation. However, secondary in vivo oxidation mechanisms have been discovered. After a preliminary post-operative analysis, we subjected highly cross-linked retrievals with 1-4 years in vivo durations and never-implanted controls to accelerated aging to predict the extent to which their oxidative stability was compromised in vivo. Lipid absorption, oxidation, and hydroperoxides were measured using infrared spectroscopy. Gravimetric swelling was used to measure cross-link density. After aging, all retrievals, except vitamin E-stabilized components, regardless of initial lipid levels or oxidation, showed significant oxidative degradation, demonstrated by subsurface oxidative peaks, increased hydroperoxides and decreased cross-link density, compared to their post-operative material properties and never-implanted counterparts, confirming oxidative stability changes.


Assuntos
Reagentes de Ligações Cruzadas/química , Oxigênio/química , Polietilenos/química , Prótese de Quadril , Humanos , Prótese do Joelho , Lipídeos/química , Oxirredução , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo , Vitamina E/química
17.
J Immunol ; 192(4): 1356-60, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24442442

RESUMO

L chain 3 (LC3)-associated phagocytosis is a process in which LC3, a protein canonically involved in engulfing intracellular materials (autophagy), is recruited to traditional phagosomes during internalization of extracellular payloads. LC3's association with phagosomes has been implicated in regulating microbial killing, Ag processing, and phagosome maturation; however, the mechanism by which LC3 influences these processes has not been clear. In this study, we report that FYVE and coiled-coil domain containing 1 (FYCO1), a protein previously implicated in autophagosome trafficking, is recruited directly by LC3 to Dectin-1 phagosomes. During LC3-associated phagocytosis, FYCO1 recruitment facilitates maturation of early p40phox(+) phagosomes into late LAMP1(+) phagosomes. When FYCO1 is lacking, phagosomes stay p40phox(+) longer and produce more reactive oxygen.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/metabolismo , Lectinas Tipo C/metabolismo , Proteínas de Membrana Lisossomal/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Fosfoproteínas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Autofagia , Células da Medula Óssea/citologia , Células Cultivadas , Células Dendríticas , Fatores de Troca do Nucleotídeo Guanina/genética , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/genética , Fagocitose/genética , Fagossomos/metabolismo , Interferência de RNA , RNA Interferente Pequeno , Transdução de Sinais/imunologia
18.
Science ; 336(6086): 1314-7, 2012 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-22674328

RESUMO

The intestinal microflora, typically equated with bacteria, influences diseases such as obesity and inflammatory bowel disease. Here, we show that the mammalian gut contains a rich fungal community that interacts with the immune system through the innate immune receptor Dectin-1. Mice lacking Dectin-1 exhibited increased susceptibility to chemically induced colitis, which was the result of altered responses to indigenous fungi. In humans, we identified a polymorphism in the gene for Dectin-1 (CLEC7A) that is strongly linked to a severe form of ulcerative colitis. Together, our findings reveal a eukaryotic fungal community in the gut (the "mycobiome") that coexists with bacteria and substantially expands the repertoire of organisms interacting with the intestinal immune system to influence health and disease.


Assuntos
Colite Ulcerativa/imunologia , Colite Ulcerativa/microbiologia , Colo/microbiologia , Fungos/imunologia , Fungos/fisiologia , Mucosa Intestinal/microbiologia , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Animais , Anticorpos Antifúngicos/sangue , Candida tropicalis/imunologia , Candida tropicalis/isolamento & purificação , Candida tropicalis/patogenicidade , Candida tropicalis/fisiologia , Colite Ulcerativa/induzido quimicamente , Colo/imunologia , Contagem de Colônia Microbiana , Sulfato de Dextrana , Suscetibilidade a Doenças , Feminino , Fungos/classificação , Fungos/isolamento & purificação , Haplótipos , Humanos , Imunidade Inata , Imunidade nas Mucosas , Mucosa Intestinal/imunologia , Intestinos/imunologia , Intestinos/microbiologia , Lectinas Tipo C/deficiência , Metagenoma , Camundongos , Camundongos Endogâmicos C57BL , Polimorfismo de Nucleotídeo Único
19.
J Immunol ; 187(11): 6002-10, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22031762

RESUMO

Signaling by innate immune receptors initiates and orchestrates the overall immune responses to infection. Macrophage receptors recognizing pathogens can be broadly grouped into surface receptors and receptors restricted to intracellular compartments, such as phagosomes and the cytoplasm. There is an expectation that ingestion and degradation of microorganisms by phagocytes contributes to activation of intracellular innate receptors, although direct demonstrations of this are rare, and many model ligands are studied in soluble form, outside of their microbial context. By comparing a wild-type strain of Staphylococcus aureus and a lysozyme-sensitive mutant, we have been able directly to address the role of degradation of live bacteria by mouse macrophages in determining the overall innate cellular inflammatory response. Our investigations revealed a biphasic response to S. aureus that consisted of an initial signal resulting from the engagement of surface TLR2, followed by a later, second wave on inflammatory gene induction. This second wave of inflammatory signaling was dependent on and correlated with the timing of bacterial degradation in phagosomes. We found that TLR2 signaling followed by TLR2/TLR9 signaling enhanced sensitivity to small numbers of bacteria. We further found that treating wild-type bacteria with the peptidoglycan synthesis-inhibiting antibiotic vancomycin made S. aureus more susceptible to degradation and resulted in increased inflammatory responses, similar to those observed for mutant degradation-sensitive bacteria.


Assuntos
Macrófagos/imunologia , Fagocitose/imunologia , Fagossomos/imunologia , Infecções Estafilocócicas/imunologia , Receptores Toll-Like/imunologia , Animais , Imunidade Inata/imunologia , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/microbiologia , Ligantes , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Knockout , Fagossomos/metabolismo , Reação em Cadeia da Polimerase , Transdução de Sinais/imunologia , Infecções Estafilocócicas/metabolismo , Staphylococcus aureus/imunologia , Receptores Toll-Like/metabolismo
20.
Nature ; 472(7344): 471-5, 2011 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-21525931

RESUMO

Innate immune cells must be able to distinguish between direct binding to microbes and detection of components shed from the surface of microbes located at a distance. Dectin-1 (also known as CLEC7A) is a pattern-recognition receptor expressed by myeloid phagocytes (macrophages, dendritic cells and neutrophils) that detects ß-glucans in fungal cell walls and triggers direct cellular antimicrobial activity, including phagocytosis and production of reactive oxygen species (ROS). In contrast to inflammatory responses stimulated upon detection of soluble ligands by other pattern-recognition receptors, such as Toll-like receptors (TLRs), these responses are only useful when a cell comes into direct contact with a microbe and must not be spuriously activated by soluble stimuli. In this study we show that, despite its ability to bind both soluble and particulate ß-glucan polymers, Dectin-1 signalling is only activated by particulate ß-glucans, which cluster the receptor in synapse-like structures from which regulatory tyrosine phosphatases CD45 and CD148 (also known as PTPRC and PTPRJ, respectively) are excluded (Supplementary Fig. 1). The 'phagocytic synapse' now provides a model mechanism by which innate immune receptors can distinguish direct microbial contact from detection of microbes at a distance, thereby initiating direct cellular antimicrobial responses only when they are required.


Assuntos
Imunidade Inata/imunologia , Sinapses Imunológicas/imunologia , Proteínas de Membrana/imunologia , Modelos Imunológicos , Proteínas do Tecido Nervoso/imunologia , Fagocitose/imunologia , Animais , Parede Celular/química , Parede Celular/imunologia , Células Cultivadas , Humanos , Lectinas Tipo C , Antígenos Comuns de Leucócito/deficiência , Antígenos Comuns de Leucócito/metabolismo , Macrófagos/imunologia , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Espécies Reativas de Oxigênio/metabolismo , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a Receptores/deficiência , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a Receptores/metabolismo , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/imunologia , Transdução de Sinais/imunologia , Solubilidade , beta-Glucanas/química , beta-Glucanas/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA