Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
EMBO Rep ; 25(3): 1156-1175, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38332148

RESUMO

Human rhinovirus is the most frequently isolated virus during severe exacerbations of chronic respiratory diseases, like chronic obstructive pulmonary disease. In this disease, alveolar macrophages display significantly diminished phagocytic functions that could be associated with bacterial superinfections. However, how human rhinovirus affects the functions of macrophages is largely unknown. Macrophages treated with HRV16 demonstrate deficient bacteria-killing activity, impaired phagolysosome biogenesis, and altered intracellular compartments. Using RNA sequencing, we identify the small GTPase ARL5b to be upregulated by the virus in primary human macrophages. Importantly, depletion of ARL5b rescues bacterial clearance and localization of endosomal markers in macrophages upon HRV16 exposure. In permissive cells, depletion of ARL5b increases the secretion of HRV16 virions. Thus, we identify ARL5b as a novel regulator of intracellular trafficking dynamics and phagolysosomal biogenesis in macrophages and as a restriction factor of HRV16 in permissive cells.


Assuntos
Macrófagos , Rhinovirus , Humanos , Macrófagos/microbiologia , Macrófagos Alveolares , Fagocitose , Bactérias
2.
Nat Methods ; 18(12): 1489-1495, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34862503

RESUMO

For quality, interpretation, reproducibility and sharing value, microscopy images should be accompanied by detailed descriptions of the conditions that were used to produce them. Micro-Meta App is an intuitive, highly interoperable, open-source software tool that was developed in the context of the 4D Nucleome (4DN) consortium and is designed to facilitate the extraction and collection of relevant microscopy metadata as specified by the recent 4DN-BINA-OME tiered-system of Microscopy Metadata specifications. In addition to substantially lowering the burden of quality assurance, the visual nature of Micro-Meta App makes it particularly suited for training purposes.


Assuntos
Metadados , Microscopia Confocal/instrumentação , Microscopia Confocal/métodos , Microscopia de Fluorescência/instrumentação , Microscopia de Fluorescência/métodos , Aplicativos Móveis , Linguagens de Programação , Software , Animais , Linhagem Celular , Biologia Computacional/métodos , Humanos , Processamento de Imagem Assistida por Computador , Camundongos , Reconhecimento Automatizado de Padrão , Controle de Qualidade , Reprodutibilidade dos Testes , Interface Usuário-Computador , Fluxo de Trabalho
3.
Cell Mol Life Sci ; 79(10): 530, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36167862

RESUMO

The endoplasmic reticulum exit of some polytopic plasma membrane proteins (PMPs) is controlled by arginin-based retention motifs. PRAF2, a gatekeeper which recognizes these motifs, was shown to retain the GABAB-receptor GB1 subunit in the ER. We report that PRAF2 can interact on a stoichiometric basis with both wild type and mutant F508del Cystic Fibrosis (CF) Transmembrane Conductance Regulator (CFTR), preventing the access of newly synthesized cargo to ER exit sites. Because of its lower abundance, compared to wild-type CFTR, CFTR-F508del recruitment into COPII vesicles is suppressed by the ER-resident PRAF2. We also demonstrate that some pharmacological chaperones that efficiently rescue CFTR-F508del loss of function in CF patients target CFTR-F508del retention by PRAF2 operating with various mechanisms. Our findings open new therapeutic perspectives for diseases caused by the impaired cell surface trafficking of mutant PMPs, which contain RXR-based retention motifs that might be recognized by PRAF2.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística , Fibrose Cística , Proteínas de Transporte/metabolismo , Membrana Celular/metabolismo , Fibrose Cística/tratamento farmacológico , Fibrose Cística/genética , Fibrose Cística/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Retículo Endoplasmático/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Mutação , Ácido gama-Aminobutírico/metabolismo
4.
J Immunol ; 205(3): 608-618, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32580933

RESUMO

Dendritic cells (DCs) are professional APCs, which sample Ags in the periphery and migrate to the lymph node where they activate T cells. DCs can also present native Ag to B cells through interactions observed both in vitro and in vivo. However, the mechanisms of Ag transfer and B cell activation by DCs remain incompletely understood. In this study, we report that murine DCs are an important cell transporter of Ag from the periphery to the lymph node B cell zone and also potent inducers of B cell activation both in vivo and in vitro. Importantly, we highlight a novel extracellular mechanism of B cell activation by DCs. In this study, we demonstrate that Ag released upon DC regurgitation is sufficient to efficiently induce early B cell activation, which is BCR driven and mechanistically dependent on the nuclear accumulation of the transcription factor NF-κB/cRel. Thus, our study provides new mechanistic insights into Ag delivery and B cell activation modalities by DCs and a promising approach for targeting NF-κB/cRel pathway to modulate the DC-elicited B cell responses.


Assuntos
Apresentação de Antígeno , Antígenos/imunologia , Linfócitos B/imunologia , Células Dendríticas/imunologia , Ativação Linfocitária , NF-kappa B/imunologia , Proteínas Proto-Oncogênicas c-rel/imunologia , Transdução de Sinais/imunologia , Animais , Antígenos/genética , Feminino , Camundongos , Camundongos Transgênicos , NF-kappa B/genética , Proteínas Proto-Oncogênicas c-rel/genética
5.
J Prosthodont ; 31(1): 50-58, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33569866

RESUMO

PURPOSE: To mechanically characterize and assess the biological properties of Ti6Al4V surfaces obtained by Selective Laser Melting in order to determine whether this process is conceivable for production of implant-supported prostheses and particularly trans-gingival components. As-built and polished surfaces were studied in comparison with components obtained by computer numerical control machining technology in order to consider whether the properties are in the same range as the conventional method currently used. MATERIALS AND METHODS: Cylindrical specimens of Ti6Al4V (n = 6) were built with Selective Laser Melting for the characterization of mechanical properties according to ISO 22674 and discs (n = 12) were fabricated in the same conditions for cytotoxicity evaluation. Discs (n = 12) of Ti6Al4V were also obtained by computer numerical control machining as control. Half of the number of discs (n = 6) from each process were polished, to simulate the laboratory protocol for polishing of transmucosal components and half of the discs remained unaltered (as-built). Surface roughness measurements of disc specimens (as-built and polished) were compared with computer numerical control milling specimens (as-built and polished). Proliferation of human gingival fibroblasts on Ti6Al4V surfaces was also assessed for each condition. Viability and cell morphology were then evaluated qualitatively. Ra and Sa data were compared using Student's t-test (α = 0.05) and metabolic activity data were compared using Kruskal-Wallis statistical test (α = 0.05). RESULTS: Selective Laser Melting specimens showed elongation at break greater than 2% and 0.2% yield strength better than 500MPa which complied with ISO 22674 standards. Although Selective Laser Melting samples displayed significantly increased roughness on as-built surfaces compared to computer numerically controlled milling samples (p < 0.05), no statistically significant difference was observed after mechanical polishing (p = 0.279). Regarding metabolic activity, no statistical difference was observed between groups at day 3 (p > 0.05) and fibroblasts showed a viability higher than 97% on all discs. Cell shapes on polished samples suggested moderate adhesion compared to unpolished samples. CONCLUSION: With the manufacturing parameters selected in this study, Selective Laser Melting of Ti6Al4V appeared to be compatible with a prosthetic application type 4 according to ISO 22674. Surfaces obtained, followed by recommended postprocessing provided components with equivalent biological properties compared to computer numerical control machining technology.


Assuntos
Implantes Dentários , Titânio , Ligas , Fibroblastos , Humanos , Lasers , Teste de Materiais , Propriedades de Superfície
6.
J Pathol ; 252(4): 451-464, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32918753

RESUMO

Skin grafting is a surgical method of cutaneous reconstruction, which provides volumetric replacement in wounds unable to heal by primary intention. Clinically, full-thickness skin grafts (FTSGs) are placed in aesthetically sensitive and mechanically demanding areas such as the hands, face, and neck. Complete or partial graft failure is the primary complication associated with this surgical procedure. Strategies aimed at improving the rate of skin graft integration will reduce the incidence of graft failure. Cold atmospheric plasma (CAP) is an emerging technology offering innovative clinical applications. The aim of this study was to test the therapeutic potential of CAP to improve wound healing and skin graft integration into the recipient site. In vitro models that mimic wound healing were used to investigate the ability of CAP to enhance cellular migration, a key factor in cutaneous tissue repair. We demonstrated that CAP enhanced the migration of epidermal keratinocytes and dermal fibroblasts. This increased cellular migration was possibly induced by the low dose of reactive oxygen and nitrogen species produced by CAP. Using a mouse model of burn wound reconstructed with a full-thickness skin graft, we showed that wounds treated with CAP healed faster than did control wounds. Immunohistochemical wound analysis showed that CAP treatment enhanced the expression of the dermal-epidermal junction components, which are vital for successful skin graft integration. CAP treatment was characterised by increased levels of Tgfbr1 mRNA and collagen I protein in vivo, suggesting enhanced wound maturity and extracellular matrix deposition. Mechanistically, we show that CAP induced the activation of the canonical SMAD-dependent TGF-ß1 pathway in primary human dermal fibroblasts, which may explain the increased collagen I synthesis in vitro. These studies revealed that CAP improved wound repair and skin graft integration via mechanisms involving extracellular matrix formation. CAP offers a novel approach for treating cutaneous wounds and skin grafts. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Queimaduras/cirurgia , Matriz Extracelular/fisiologia , Queratinócitos/fisiologia , Gases em Plasma/uso terapêutico , Reepitelização/fisiologia , Transplante de Pele/métodos , Cicatrização/fisiologia , Animais , Queimaduras/fisiopatologia , Movimento Celular/fisiologia , Proliferação de Células , Camundongos , Modelos Animais , Fenômenos Fisiológicos da Pele , Resultado do Tratamento
7.
Int J Mol Sci ; 22(20)2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34681924

RESUMO

Cyclic fertilin peptide (cFEE: phenylalanine, glutamic acid; glutamic acid) improves gamete interaction in humans. We investigate whether it could be via improvement of sperm movement parameters and their mitochondrial ATP production. Sperm movement parameters were studied using computer-assisted sperm analysis (CASA) in sperm samples from 38 patients with normal sperm in medium supplemented with cyclic fertilin against a control group. Sperm mitochondrial functions were studied using donor's sperm, incubated or not with cFEE. It was evaluated by the measurement of their ATP production using bioluminescence, their respiration by high resolution oxygraphy, and of mitochondrial membrane potential (MMP) using potentiometric dyes and flow cytometry. cFEE significantly improved sperm movement parameters and percentage of hyperactivated sperm. Impact of inhibitors showed OXPHOS as the predominant energy source for sperm movement. However, cFEE had no significant impact on any of the analyzed mitochondrial bioenergetic parameters, suggesting that it could act via a more efficient use of its energy resources.


Assuntos
Mitocôndrias/metabolismo , Peptídeos Cíclicos/farmacologia , Espermatozoides/fisiologia , Trifosfato de Adenosina/metabolismo , Metabolismo Energético , Humanos , Medições Luminescentes , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Membranas/metabolismo , Mitocôndrias/efeitos dos fármacos , Fosforilação Oxidativa , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos
8.
Gut ; 69(2): 355-364, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-30979717

RESUMO

OBJECTIVES: Polyploidy is a fascinating characteristic of liver parenchyma. Hepatocyte polyploidy depends on the DNA content of each nucleus (nuclear ploidy) and the number of nuclei per cell (cellular ploidy). Which role can be assigned to polyploidy during human hepatocellular carcinoma (HCC) development is still an open question. Here, we investigated whether a specific ploidy spectrum is associated with clinical and molecular features of HCC. DESIGN: Ploidy spectra were determined on surgically resected tissues from patients with HCC as well as healthy control tissues. To define ploidy profiles, a quantitative and qualitative in situ imaging approach was used on paraffin tissue liver sections. RESULTS: We first demonstrated that polyploid hepatocytes are the major components of human liver parenchyma, polyploidy being mainly cellular (binuclear hepatocytes). Across liver lobules, polyploid hepatocytes do not exhibit a specific zonation pattern. During liver tumorigenesis, cellular ploidy is drastically reduced; binuclear polyploid hepatocytes are barely present in HCC tumours. Remarkably, nuclear ploidy is specifically amplified in HCC tumours. In fact, nuclear ploidy is amplified in HCCs harbouring a low degree of differentiation and TP53 mutations. Finally, our results demonstrated that highly polyploid tumours are associated with a poor prognosis. CONCLUSIONS: Our results underline the importance of quantification of cellular and nuclear ploidy spectra during HCC tumorigenesis.


Assuntos
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Poliploidia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Estudos de Casos e Controles , Diferenciação Celular/genética , Núcleo Celular/patologia , Proliferação de Células/genética , Transformação Celular Neoplásica/genética , Feminino , Hepatócitos/patologia , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Prognóstico , Adulto Jovem
10.
Stem Cells ; 37(5): 701-711, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30674073

RESUMO

Stem cells endowed with skeletogenic potentials seeded in specific scaffolds are considered attractive tissue engineering strategies for treating large bone defects. In the context of craniofacial bone, mesenchymal stromal/stem cells derived from the dental pulp (DPSCs) have demonstrated significant osteogenic properties. Their neural crest embryonic origin further makes them a potential accessible therapeutic tool to repair craniofacial bone. The stem cells' direct involvement in the repair process versus a paracrine effect is however still discussed. To clarify this question, we have followed the fate of fluorescent murine DPSCs derived from PN3 Wnt1-CRE- RosaTomato mouse molar (T-mDPSCs) during the repair process of calvaria bone defects. Two symmetrical critical defects created on each parietal region were filled with (a) dense collagen scaffolds seeded with T-mDPSCs, (b) noncellularized scaffolds, or (c) no scaffold. Mice were imaged over a 3-month period by microcomputed tomography to evaluate the extent of repair and by biphotonic microscopy to track T-mDPSCs. Histological and immunocytochemical analyses were performed in parallel to characterize the nature of the repaired tissue. We show that T-mDPSCs are present up to 3 months postimplantation in the healing defect and that they rapidly differentiate in chondrocyte-like cells expressing all the expected characteristic markers. T-mDPSCs further maturate into hypertrophic chondrocytes and likely signal to host progenitors that form new bone tissue. This demonstrates that implanted T-mDPSCs are able to survive in the defect microenvironment and to participate directly in repair via an endochondral bone ossification-like process. Stem Cells 2019;37:701-711.


Assuntos
Regeneração Óssea/genética , Osteogênese/genética , Crânio/crescimento & desenvolvimento , Proteína Wnt1/genética , Animais , Diferenciação Celular/genética , Condrogênese/genética , Polpa Dentária/crescimento & desenvolvimento , Humanos , Integrases/genética , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Células-Tronco/citologia , Engenharia Tecidual
11.
J Immunol ; 199(6): 1998-2007, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28779024

RESUMO

So far, peripheral T cells have mostly been described to circulate between blood, secondary lymphoid organs (SLOs), and lymph in the steady state. This nomadic existence would allow them to accomplish their surveying task for both foreign Ags and survival signals. Although it is now well established that γδ T cells can be rapidly recruited to inflammatory sites or in certain tumor microenvironments, the trafficking properties of peripheral γδ T cells have been poorly studied in the steady state. In the present study, we highlight the existence of resident γδ T cells in the SLOs of specific pathogen-free mice. Indeed, using several experimental approaches such as the injection of integrin-neutralizing Abs that inhibit the entry of circulating lymphocytes into lymph nodes and long-term parabiosis experiments, we have found that, contrary to Ly-6C-/+CD44lo and Ly-6C+CD44hi γδ T cells, a significant proportion of Ly-6C-CD44hi γδ T cells are trapped for long periods of time within lymph nodes and the spleen in the steady state. Specific in vivo cell depletion strategies have allowed us to demonstrate that macrophages are the main actors involved in this long-term retention of Ly-6C-CD44hi γδ T cells in SLOs.


Assuntos
Linfonodos/imunologia , Macrófagos/imunologia , Baço/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T/imunologia , Animais , Antígenos Ly/metabolismo , Comunicação Celular , Movimento Celular , Células Cultivadas , Receptores de Hialuronatos/metabolismo , Imunidade Inata , Vigilância Imunológica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo
12.
Proc Natl Acad Sci U S A ; 113(27): E3901-10, 2016 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-27298374

RESUMO

Treatment for fibrosis represents a critical unmet need, because fibrosis is the leading cause of death in industrialized countries, and there is no effective therapy to counteract the fibrotic process. The development of fibrosis relates to the interplay between vessel injury, immune cell activation, and fibroblast stimulation, which can occur in various tissues. Immunotherapies have provided a breakthrough in the treatment of immune diseases. The glycoprotein OX40-OX40 ligand (OX40L) axis offers the advantage of a targeted approach to costimulatory signals with limited impact on the whole immune response. Using systemic sclerosis (SSc) as a prototypic disease, we report compelling evidence that blockade of OX40L is a promising strategy for the treatment of inflammation-driven fibrosis. OX40L is overexpressed in the fibrotic skin and serum of patients with SSc, particularly in patients with diffuse cutaneous forms. Soluble OX40L was identified as a promising serum biomarker to predict the worsening of lung and skin fibrosis, highlighting the role of this pathway in fibrosis. In vivo, OX40L blockade prevents inflammation-driven skin, lung, and vessel fibrosis and induces the regression of established dermal fibrosis in different complementary mouse models. OX40L exerts potent profibrotic effects by promoting the infiltration of inflammatory cells into lesional tissues and therefore the release of proinflammatory mediators, thereafter leading to fibroblast activation.


Assuntos
Ligante OX40/antagonistas & inibidores , Ligante OX40/sangue , Fibrose Pulmonar/prevenção & controle , Escleroderma Sistêmico/sangue , Pele/patologia , Animais , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Biomarcadores/sangue , Bleomicina , Estudos de Casos e Controles , Células Cultivadas , Avaliação Pré-Clínica de Medicamentos , Fibrose , Antígeno 2 Relacionado a Fos/genética , Humanos , Hipertensão Pulmonar/prevenção & controle , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Fibrose Pulmonar/genética , Escleroderma Sistêmico/tratamento farmacológico , Pele/metabolismo , Fator de Transcrição AP-1/metabolismo
13.
Int J Mol Sci ; 19(12)2018 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-30567353

RESUMO

BACKGROUND: Pulmonary hypertension (PH) is a common complication of idiopathic pulmonary fibrosis (IPF) that significantly contributes to morbidity and mortality. Macrophage migration inhibitory factor (MIF) is a critical factor in vascular remodeling of the pulmonary circulation. OBJECTIVES: We tested the effects of two small molecules targeting MIF on bleomycin (BLM)-induced collagen deposition, PH, and vascular remodeling in mouse lungs. METHODS: We examined the distribution pattern of MIF, CD74, and CXCR4 in the lungs of patients with IPF-PH and the lungs of BLM-injected mice. Then, treatments were realized with (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1) and N-(3-hydroxy-4-fluorobenzyl)-5 trifluoromethylbenzoxazol-2-thione 31 (20 mg/kg/day per os for 3 weeks) started 24 h after an intratracheal BLM administration. RESULTS: More intense immunoreactivity was noted for MIF, CD74, and CXCR4 in lungs from IPF-PH patients and BLM-injected mice. Furthermore, we found that treatments of BLM-injected mice with ISO-1 or compound 31 attenuated lung collagen deposition and right ventricular systolic pressure increase. Additionally, reduced pulmonary inflammatory infiltration and pulmonary arterial muscularization were observed in the lungs of BLM-injected mice treated with ISO-1 or compound 31. CONCLUSIONS: Treatments with ISO-1 or compound 31 attenuates BLM-induced inflammation and fibrosis in lung, and prevents PH development in mice, suggesting that MIF is an important factor for IPF-PH development.


Assuntos
Hipertensão Pulmonar/tratamento farmacológico , Fibrose Pulmonar Idiopática/tratamento farmacológico , Inflamação/tratamento farmacológico , Oxirredutases Intramoleculares/genética , Fatores Inibidores da Migração de Macrófagos/genética , Animais , Antígenos de Diferenciação de Linfócitos B/genética , Bleomicina/toxicidade , Modelos Animais de Doenças , Feminino , Antígenos de Histocompatibilidade Classe II/genética , Humanos , Hipertensão Pulmonar/induzido quimicamente , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/patologia , Fibrose Pulmonar Idiopática/induzido quimicamente , Fibrose Pulmonar Idiopática/genética , Fibrose Pulmonar Idiopática/patologia , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/patologia , Isoxazóis/administração & dosagem , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Camundongos , Receptores CXCR4/genética , Remodelação Vascular/efeitos dos fármacos , Remodelação Vascular/genética
14.
Ann Rheum Dis ; 76(11): 1931-1940, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28801346

RESUMO

OBJECTIVE: To evaluate the antifibrotic effects of the pan-peroxisome proliferator-activated receptor (PPAR) agonist IVA337 in preclinical mouse models of pulmonary fibrosis and related pulmonary hypertension (PH). METHODS: IVA337 has been evaluated in the mouse model of bleomycin-induced pulmonary fibrosis and in Fra-2 transgenic mice, this latter being characterised by non-specific interstitial pneumonia and severe vascular remodelling of pulmonary arteries leading to PH. Mice received two doses of IVA337 (30 mg/kg or 100 mg/kg) or vehicle administered by daily oral gavage up to 4 weeks. RESULTS: IVA337 demonstrated at a dose of 100 mg/kg a marked protection from the development of lung fibrosis in both mouse models compared with mice receiving 30 mg/kg of IVA337 or vehicle. Histological score was markedly reduced by 61% in the bleomycin model and by 50% in Fra-2 transgenic mice, and total lung hydroxyproline concentrations decreased by 28% and 48%, respectively, as compared with vehicle-treated mice. IVA337 at 100 mg/kg also significantly decreased levels of fibrogenic markers in lesional lungs of both mouse models. In addition, IVA337 substantially alleviated PH in Fra-2 transgenic mice by improving haemodynamic measurements and vascular remodelling. In primary human lung fibroblasts, IVA337 inhibited in a dose-dependent manner fibroblast to myofibroblasts transition induced by TGF-ß and fibroblast proliferation mediated by PDGF. CONCLUSION: We demonstrate that treatment with 100 mg/kg IVA337 prevents lung fibrosis in two complementary animal models and substantially attenuates PH in the Fra-2 mouse model. These findings confirm that the pan-PPAR agonist IVA337 is an appealing therapeutic candidate for these cardiopulmonary involvements.


Assuntos
Benzotiazóis/farmacologia , Hipertensão Pulmonar/tratamento farmacológico , Fibrose Pulmonar/tratamento farmacológico , Sulfonamidas/farmacologia , Animais , Bleomicina , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Fibroblastos/efeitos dos fármacos , Antígeno 2 Relacionado a Fos , Hipertensão Pulmonar/etiologia , Camundongos , Camundongos Transgênicos , Miofibroblastos/efeitos dos fármacos , Artéria Pulmonar/efeitos dos fármacos , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/complicações , Índice de Gravidade de Doença , Fator de Crescimento Transformador beta/agonistas , Fator de Crescimento Transformador beta/fisiologia , Resultado do Tratamento , Remodelação Vascular/efeitos dos fármacos
15.
Ann Rheum Dis ; 75(12): 2175-2183, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26961294

RESUMO

BACKGROUND: The pathogenesis of systemic sclerosis (SSc) involves a distinctive triad of autoimmune, vascular and inflammatory alterations resulting in fibrosis. Evidence suggests that peroxisome proliferator-activated receptors (PPARs) play an important role in SSc-related fibrosis and their agonists may become effective therapeutic targets. OBJECTIVE: To determine the expression of PPARs in human fibrotic skin and investigate the effects of IVA337, a pan PPAR agonist, in in vitro and in vivo models of fibrosis. METHODS: The antifibrotic effects of IVA337 were studied using a bleomycin-induced mouse model of dermal fibrosis. The in vivo effect of IVA337 on wound closure and inflammation were studied using an excisional model of wound healing. RESULTS: Low levels of PPARα and PPARγ were detected in the skin of patients with SSc compared with controls. In mice, IVA337 was associated with decreased extracellular matrix (ECM) deposition and reduced expression of phosphorylated SMAD2/3-intracellular effector of transforming growth factor (TGF)-ß1. Although the antifibrotic effect of pan PPAR was similar to that of PPARγ agonist alone, a significant downregulation of several markers of inflammation was associated with IVA337. Despite its anti-inflammatory and antifibrotic properties, IVA337 did not interfere with wound closure. In vitro effects of IVA337 included attenuation of transcription of ECM genes and alteration of canonical and non-canonical TGF-ß signalling pathways. CONCLUSIONS: These findings indicate that simultaneous activation of all three PPAR isoforms exerts a dampening effect on inflammation and fibrosis, making IVA337 a potentially effective therapeutic candidate in the treatment of fibrotic diseases including SSc.


Assuntos
Anti-Inflamatórios/farmacologia , Benzotiazóis/farmacologia , Fármacos Dermatológicos/farmacologia , PPAR alfa/agonistas , PPAR gama/agonistas , Escleroderma Sistêmico/tratamento farmacológico , Escleroderma Sistêmico/patologia , Sulfonamidas/farmacologia , Animais , Bleomicina , Modelos Animais de Doenças , Matriz Extracelular/efeitos dos fármacos , Fibrose , Humanos , Camundongos , PPAR alfa/metabolismo , PPAR gama/metabolismo , Escleroderma Sistêmico/induzido quimicamente , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Cicatrização/efeitos dos fármacos
16.
Rheumatology (Oxford) ; 55(3): 470-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26424834

RESUMO

OBJECTIVE: Outcome of JDM is highly heterogeneous. Our objective was to determine clinical and muscle biopsy features associated with poor outcome and response to treatment. METHODS: Clinical data and muscle biopsy were obtained from a monocentric cohort of 29 patients. Clinical subgroups were defined by latent class model analysis of initial and follow-up parameters. Myopathological features were analysed using validated scores. Capillary loss was determined on reconstructions of transversal sections and assessed in the different age groups to take into account variations of muscle capillarization during post-natal development. Regression models were used to identify initial predictors of therapeutic response. RESULTS: Two distinct homogeneous subgroups of patients were identified according to clinical severity and pathological findings. The smallest group of patients (7/29) presented with severe JDM. Compared with the other group (22/29), patients had more severe muscle weakness at disease onset, low remission rate at 12 months, frequent subcutaneous limb oedema or gastrointestinal (GI) involvement and higher myopathological scores (capillary dropout, perifascicular necrosis/regeneration, fibres with internal myonuclei and fibrosis subscores). Relevance of capillary dropout to JDM severity was substantiated by age-based analysis, confirming its major role in JDM pathophysiology. Most of these manifestations could be related to vasculopathy (limb oedema, GI involvement, capillary dropout). Furthermore, Childhood Myositis Assessment Scale <34 with either GI involvement or muscle endomysial fibrosis at disease onset were the best predictors of poor response to treatment. CONCLUSION: Vasculopathy is prominent in severe JDM. Simple criteria can be used at initial evaluation to identify patients requiring a more intensive therapy.


Assuntos
Dermatomiosite/patologia , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/patologia , Doenças Vasculares/patologia , Adolescente , Biópsia por Agulha , Capilares/patologia , Criança , Pré-Escolar , Estudos de Coortes , Dermatomiosite/complicações , Dermatomiosite/fisiopatologia , Progressão da Doença , Feminino , França , Humanos , Imuno-Histoquímica , Masculino , Prognóstico , Valores de Referência , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Doenças Vasculares/complicações , Doenças Vasculares/fisiopatologia
17.
BMC Biol ; 12: 773, 2014 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-25551479

RESUMO

BACKGROUND: The public health threats imposed by toxoplasmosis worldwide and by malaria in sub-Saharan countries are directly associated with the capacity of their related causative agents Toxoplasma and Plasmodium, respectively, to colonize and expand inside host cells. Therefore, deciphering how these two Apicomplexan protozoan parasites access their host cells has been highlighted as a priority research with the perspective of designing anti-invasive molecules to prevent diseases. Central to the mechanism of invasion for both genera is mechanical force, which is thought to be applied by the parasite at the interface between the two cells following assembly of a unique cell-cell junction but this model lacks direct evidence and has been challenged by recent genetic studies. In this work, using parasites expressing the fluorescent core component of this junction, we analyze characteristic features of the kinematics of penetration of more than 1,000 invasion events. RESULTS: The majority of invasion events occur with a typical forward rotational progression of the parasite through a static junction into an invaginating host cell plasma membrane. However, if parasites encounter resistance and if the junction is not strongly anchored to the host cell cortex, as when parasites do not secrete the toxofilin protein and, therefore, are unable to locally remodel the cortical actin cytoskeleton, the junction travels retrogradely with the host cell membrane along the parasite surface allowing the formation of a functional vacuole. Kinetic measurements of the invasive trajectories strongly support a similar parasite driven force in both static and capped junctions, both of which lead to successful invasion. However, about 20% of toxofilin mutants fail to enter and eventually disengage from the host cell membrane while the secreted RhOptry Neck (RON2) molecules are posteriorally capped before being cleaved and released in the medium. By contrast in cells characterized by low cortex tension and high cortical actin dynamics junction capping and entry failure are drastically reduced. CONCLUSIONS: This kinematic analysis newly highlights that to invade cells parasites need to engage their motor with the junction molecular complex where force is efficiently applied only upon proper anchorage to the host cell membrane and cortex.


Assuntos
Interações Hospedeiro-Parasita/fisiologia , Junções Intercelulares/parasitologia , Plasmodium/fisiologia , Proteínas de Protozoários/metabolismo , Toxoplasma/fisiologia , Proteínas de Capeamento de Actina/genética , Proteínas de Capeamento de Actina/metabolismo , Actinas/metabolismo , Membrana Celular/metabolismo , Células Cultivadas/parasitologia , Interações Hospedeiro-Parasita/genética , Humanos , Proteínas Luminescentes/genética , Modelos Biológicos , Proteínas de Protozoários/genética
18.
J Cell Biol ; 222(11)2023 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-37847528

RESUMO

In parallel with the development of tissue-clearing methods, over the last decade, light sheet fluorescence microscopy has contributed to major advances in various fields, such as cell and developmental biology and neuroscience. While biologists are increasingly integrating three-dimensional imaging into their research projects, their experience with the technique is not always up to their expectations. In response to a survey of specific challenges associated with sample clearing and labeling, image acquisition, and data analysis, we have critically assessed the recent literature to characterize the difficulties inherent to light sheet fluorescence microscopy applied to cleared biological samples and to propose solutions to overcome them. This review aims to provide biologists interested in light sheet fluorescence microscopy with a primer for the development of their imaging pipeline, from sample preparation to image analysis. Importantly, we believe that issues could be avoided with better anticipation of image analysis requirements, which should be kept in mind while optimizing sample preparation and acquisition parameters.


Assuntos
Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Microscopia de Fluorescência , Imageamento Tridimensional/métodos , Microscopia de Fluorescência/métodos
19.
iScience ; 26(4): 106286, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-36942053

RESUMO

Animal models for studying human pathogens are crucially lacking. We describe the implantation in mice of engineered human mature microvasculature consisting of endothelial and perivascular cells embedded in collagen hydrogel that allows investigation of pathogen interactions with the endothelium, including in vivo functional studies. Using Neisseria meningitidis as a paradigm of human-restricted infection, we demonstrated the strength and opportunities associated with the use of this approach.

20.
Nat Commun ; 14(1): 3835, 2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-37380648

RESUMO

Takotsubo cardiomyopathy is a stress-induced cardiovascular disease with symptoms comparable to those of an acute coronary syndrome but without coronary obstruction. Takotsubo was initially considered spontaneously reversible, but epidemiological studies revealed significant long-term morbidity and mortality, the reason for which is unknown. Here, we show in a female rodent model that a single pharmacological challenge creates a stress-induced cardiomyopathy similar to Takotsubo. The acute response involves changes in blood and tissue biomarkers and in cardiac in vivo imaging acquired with ultrasound, magnetic resonance and positron emission tomography. Longitudinal follow up using in vivo imaging, histochemistry, protein and proteomics analyses evidences a continued metabolic reprogramming of the heart towards metabolic malfunction, eventually leading to irreversible damage in cardiac function and structure. The results combat the supposed reversibility of Takotsubo, point to dysregulation of glucose metabolic pathways as a main cause of long-term cardiac disease and support early therapeutic management of Takotsubo.


Assuntos
Modelos Animais de Doenças , Coração , Estresse Psicológico , Cardiomiopatia de Takotsubo , Humanos , Feminino , Animais , Ratos , Cardiomiopatia de Takotsubo/metabolismo , Cardiomiopatia de Takotsubo/patologia , Ratos Wistar , Coração/fisiopatologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Glucose-6-Fosfato/metabolismo , Glicólise , Estresse Psicológico/complicações
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa