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1.
Biomacromolecules ; 21(1): 230-239, 2020 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-31609592

RESUMO

We demonstrate here, for the first time, formation of injectable dynamic covalent hydrogels at physiological pH using benzoxaborin-saccharide complexation as a reversible cross-linking method. The gels were prepared by simply mixing hyaluronic acid modified with an original boronic acid derivative, 3,4-dihydro-2H-benzo[e][1,2]oxaborinin-2-ol (1,2-ABORIN), and HA functionalized with 1-amino-1-deoxy-d-fructose. Dynamic rheological experiments confirmed the gel-like behavior (storage modulus (G') > loss modulus (G″) in the frequency window explored) for the designed HA-1,2-ABORIN/HA-fructose network. Furthermore, this hydrogel exhibited excellent self-healing and injectability behaviors in aqueous conditions and was found to be responsive to pH. Additionally, fibroblast cells encapsulated in the HA network showed high viability (>80% after 7 days of cell culture), as monitored by Live/Dead staining. Taken together, this new class of boronate ester cross-linked hydrogel provides promising future for diverse biomedical applications.


Assuntos
Técnicas de Cultura de Células/métodos , Ácido Hialurônico/química , Hidrogéis/química , Animais , Ácidos Borínicos/química , Ácidos Borônicos/química , Técnicas de Cultura de Células/instrumentação , Sobrevivência Celular , Fibroblastos/citologia , Frutose/química , Concentração de Íons de Hidrogênio , Injeções , Espectroscopia de Ressonância Magnética , Camundongos , Reologia
2.
Cerebrovasc Dis ; 38(5): 344-53, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25427570

RESUMO

BACKGROUND: Microvasculature plays a key role in stroke pathophysiology both during initial damage and extended neural repair. Moreover, angiogenesis processes seem to be a promising target for future neurorestorative therapies. However, dynamic changes of microvessels after stroke still remain unclear, and MRI follow-up could be interesting as an in vivo biomarker of these. METHODS: The aim of this study is to characterize the microvascular plasticity 25 days after ischemic stroke using both in vivo microvascular 7T-MRI (vascular permeability, cerebral blood volume (CBV), vessel size index (VSI), vascular density) and quantification of angiogenic factor expressions by RT-qPCR in a transient middle cerebral artery occlusion rat model. CBV and VSI (perfused vessel caliber) imaging was performed using a steady-state approach with a multi gradient-echo spin-echo sequence before and 2 min after intravenous (IV) injection of ultrasmall superparamagnetic iron particles. Vascular density (per mm2) was derived from the ratio [ΔR2/(ΔR2*)²/³]. Blood brain barrier leakage was assessed using T1W images before and after IV injection of Gd-DOTA. Additionally, microvessel immunohistology was done. RESULTS: 3 successive stages were observed: 1) 'Acute stage' from day 1 to day 3 post-stroke (D1-D3) characterized by high levels of angiopoietin-2 (Ang2), vascular endothelial growth factor receptor-2 (VEGFR-2) and endothelial NO synthase (eNOS) that may be associated with deleterious vascular permeability and vasodilation; 2) 'Transition stage' (D3-D7) that involves transforming the growth factors ß1 (TGFß1), Ang1, and tyrosine kinase with immunoglobulin-like and endothelial growth factor-like domains 1 (Tie1), stromal-derived factor-1 (SDF-1), chemokine receptor type 4 (CXCR-4); and 3) 'Subacute stage' (D7-D25) with high levels of Ang1, Ang2, VEGF, VEGFR-1 and TGFß1 leading to favorable stabilization and maturation of microvessels. In vivo MRI appeared in line with the angiogenic factors changes with a delay of at least 1 day. All MRI parameters varied over time, revealing the different aspects of the post-stroke microvascular plasticity. At D25, despite a normal CBV, MRI revealed a limited microvessel density, which is insufficient to support a good neural repair. CONCLUSIONS: Microvasculature MRI can provide imaging of different states of functional (perfused) microvessels after stroke. These results highlight that multiparametric MRI is useful to assess post-stroke angiogenesis, and could be used as a biomarker notably for neurorestorative therapy studies. Additionally, we identified that endogenous vessel maturation and stabilization occur during the 'subacute stage'. Thus, pro-angiogenic treatments, such as cell-based therapy, would be relevant during this subacute phase of stroke.


Assuntos
Imageamento por Ressonância Magnética , Microvasos/patologia , Acidente Vascular Cerebral/patologia , Animais , Barreira Hematoencefálica/patologia , Permeabilidade Capilar , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Ratos Sprague-Dawley , Acidente Vascular Cerebral/complicações , Fator A de Crescimento do Endotélio Vascular/metabolismo
3.
Theranostics ; 14(10): 4147-4160, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38994025

RESUMO

Impact: The permeabilization of the BBB to deliver therapeutics with MR-guided FUS redefines therapeutic strategies as it improves patient outcomes. To ensure the best translation towards clinical treatment, the evaluation of hemodynamic modifications in the CNS is necessary to refine treatment parameters. Methods: MR-guided FUS was applied at 1.5 MHz with a 50 ms burst every 1 s to open the BBB. CBF, BVf and ADC parameters were monitored with MRI. Cavitation was monitored with a PCD during the FUS sequence and classified with the IUD index into three cavitation levels. We distinctly applied the FUS in the cortex or the striatum. After the BBB permeabilization, neuroinflammation markers were quantified longitudinally. Results: The BBB was successfully opened in all animals in this study and only one animal was classified as "hard" and excluded from the rest of the study. 30 min after FUS-induced BBB opening in the cortex, we measured a 54% drop in CBF and a 13% drop in BVf compared to the contralateral side. After permeabilization of the striatum, a 38% drop in CBF and a 15% drop in BVf were measured. CBF values rapidly returned to baseline, and 90 min after BBB opening, no significant differences were observed. We quantified the subsequent neuroinflammation, noting a significant increase in astrocytic recruitment at 2 days and microglial activation at 1 day after FUS. After 7 days, no more inflammation was visible in the brain. Conclusion: FUS-induced BBB opening transiently modifies hemodynamic parameters such as CBF and BVf, suggesting limited nutrients and oxygen supply to the CNS in the hour following the procedure.


Assuntos
Barreira Hematoencefálica , Imageamento por Ressonância Magnética , Animais , Barreira Hematoencefálica/metabolismo , Imageamento por Ressonância Magnética/métodos , Inflamação/metabolismo , Encéfalo/metabolismo , Circulação Cerebrovascular , Masculino , Doenças Neuroinflamatórias/metabolismo , Ratos , Corpo Estriado/metabolismo
4.
Int J Radiat Oncol Biol Phys ; 119(5): 1506-1516, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38373658

RESUMO

PURPOSE: Synchrotron microbeam radiation therapy (MRT), based on an inhomogeneous geometric and microscopic irradiation pattern of the tissues with high-dose and high-dose-rate x-rays, enhances the permeability of brain tumor vessels. This study attempted to determine the time and size range of the permeability window induced by MRT in the blood-brain (tumor) barrier. METHODS AND MATERIALS: Rats-bearing 9L gliomas were exposed to MRT, either unidirectional (tumor dose, 406 Gy) or bidirectional (crossfired) (2 × 203 Gy). We measured vessel permeability to molecules of 3 sizes (Gd-DOTA, Dotarem, 0.56 kDa; gadolinium-labeled albumin, ∼74 kDa; and gadolinium-labeled IgG, 160 kDa) by daily in vivo magnetic resonance imaging, from 1 day before to 10 days after irradiation. RESULTS: An equivalent tumor dose of bidirectional MRT delivered from 2 orthogonal directions increased tumor vessel permeability for the smallest molecule tested more effectively than unidirectional MRT. Bidirectional MRT also affected the permeability of normal contralateral vessels to a different extent than unidirectional MRT. Conversely, bidirectional MRT did not modify the permeability of normal or tumor vessels for both larger molecules (74 and 160 kDa). CONCLUSIONS: High-dose bidirectional (cross-fired) MRT induced a significant increase in tumor vessel permeability for small molecules between the first and the seventh day after irradiation, whereas permeability of vessels in normal brain tissue remained stable. Such a permeability window could facilitate an efficient and safe delivery of intravenous small molecules (≤0.56 kDa) to tumoral tissues. A permeability window was not achieved by molecules larger than gado-grafted albumin (74 kDa). Vascular permeability for molecules between these 2 sizes has not been determined.


Assuntos
Barreira Hematoencefálica , Neoplasias Encefálicas , Permeabilidade Capilar , Meios de Contraste , Imageamento por Ressonância Magnética , Compostos Organometálicos , Ratos Endogâmicos F344 , Síncrotrons , Animais , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Permeabilidade Capilar/efeitos da radiação , Ratos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/efeitos da radiação , Imageamento por Ressonância Magnética/métodos , Compostos Organometálicos/farmacocinética , Meios de Contraste/farmacocinética , Gadolínio/farmacocinética , Fatores de Tempo , Masculino , Imunoglobulina G , Albuminas/metabolismo , Albuminas/farmacocinética , Glioma/radioterapia , Glioma/irrigação sanguínea , Glioma/metabolismo , Glioma/diagnóstico por imagem , Glioma/patologia , Dosagem Radioterapêutica , Compostos Heterocíclicos
5.
Neuroscience ; 2023 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-38013148

RESUMO

Stroke is the most common cause of disability. Brain repair mechanisms are often insufficient to allow a full recovery. Stroke damage involve all brain cell type and extracellular matrix which represent the crucial "glio-neurovascular niche" useful for brain plasticity. Regenerative medicine including cell therapies hold great promise to decrease post-stroke disability of many patients, by promoting both neuroprotection and neural repair through direct effects on brain lesion and/or systemic effects such as immunomodulation. Mechanisms of action vary according to each grafted cell type: "peripheral" stem cells, such as mesenchymal stem cells (MSC), can provide paracrine trophic support, and neural stem/progenitor cells (NSC) or neurons can act as direct cells' replacements. Optimal time window, route, and doses are still debated, and may depend on the chosen medicinal product and its expected mechanism such as neuroprotection, delayed brain repair, systemic effects, or graft survival and integration in host network. MSC, mononuclear cells (MNC), umbilical cord stem cells and NSC are the most investigated. Innovative approaches are implemented concerning combinatorial approaches with growth factors and biomaterials such as injectable hydrogels which could protect a cell graft and/or deliver drugs into the post-stroke cavity at chronic stages. Through main publications of the last two decades, we provide in this review concepts and suggestions to improve future translational researches and larger clinical trials of cell therapy in stroke.

6.
bioRxiv ; 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37131613

RESUMO

Cell therapy is promising to treat many conditions, including neurological and osteoarticular diseases. Encapsulation of cells within hydrogels facilitates cell delivery and can improve therapeutic effects. However, much work remains to be done to align treatment strategies with specific diseases. The development of imaging tools that enable monitoring cells and hydrogel independently is key to achieving this goal. Our objective herein is to longitudinally study an iodine-labeled hydrogel, incorporating gold-labeled stem cells, by bicolor CT imaging after in vivo injection in rodent brains or knees. To this aim, an injectable self-healing hyaluronic acid (HA) hydrogel with long-persistent radiopacity was formed by the covalent grafting of a clinical contrast agent on HA. The labeling conditions were tuned to achieve sufficient X-ray signal and to maintain the mechanical and self-healing properties as well as injectability of the original HA scaffold. The efficient delivery of both cells and hydrogel at the targeted sites was demonstrated by synchrotron K-edge subtraction-CT. The iodine labeling enabled to monitor the hydrogel biodistribution in vivo up to 3 days post-administration, which represents a technological first in the field of molecular CT imaging agents. This tool may foster the translation of combined cell-hydrogel therapies into the clinics.

7.
Mol Pharm ; 9(2): 211-21, 2012 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-22142367

RESUMO

Our goal was to demonstrate the in vivo tumor specific accumulation of crotamine, a natural peptide from the venom of the South American rattlesnake Crotalus durissus terrificus, which has been characterized by our group as a cell penetrating peptide with a high specificity for actively proliferating cells and with a concentration-dependent cytotoxic effect. Crotamine cytotoxicity has been shown to be dependent on the disruption of lysosomes and subsequent activation of intracellular proteases. In this work, we show that the cytotoxic effect of crotamine also involves rapid intracellular calcium release and loss of mitochondrial membrane potential as observed in real time by confocal microscopy. The intracellular calcium overload induced by crotamine was almost completely blocked by thapsigargin. Microfluorimetry assays confirmed the importance of internal organelles, such as lysosomes and the endoplasmic reticulum, as contributors for the intracellular calcium increase, as well as the extracellular medium. Finally, we demonstrate here that crotamine injected intraperitoneally can efficiently target remote subcutaneous tumors engrafted in nude mice, as demonstrated by a noninvasive optical imaging procedure that permits in vivo real-time monitoring of crotamine uptake into tumor tissue. Taken together, our data indicate that the cytotoxic peptide crotamine can be used potentially for a dual purpose: to target and detect growing tumor tissues and to selectively trigger tumor cell death.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Peptídeos Penetradores de Células/administração & dosagem , Venenos de Crotalídeos/administração & dosagem , Neoplasias/metabolismo , Animais , Antineoplásicos , Células CHO , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Peptídeos Penetradores de Células/farmacocinética , Cricetinae , Cricetulus , Venenos de Crotalídeos/farmacocinética , Crotalus , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Citometria de Fluxo , Células HEK293 , Humanos , Injeções Intraperitoneais , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Nus , Microscopia Confocal , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Tapsigargina/farmacologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Sci Rep ; 12(1): 4700, 2022 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-35304540

RESUMO

With the aim of designing a preclinical study evaluating an intracerebral cell-based therapy for stroke, an observational study was performed in the rat suture model of ischemic stroke. Objectives were threefold: (i) to characterize neurofunctional and imaging readouts in the first weeks following transient ischemic stroke, according to lesion subtype (hypothalamic, striatal, corticostriatal); (ii) to confirm that intracerebral administration does not negatively impact these readouts; and (iii) to calculate sample sizes for a future therapeutic trial using these readouts as endpoints. Our results suggested that the most relevant endpoints were side bias (staircase test) and axial diffusivity (AD) (diffusion tensor imaging). Hypothalamic-only lesions did not affect those parameters, which were close to normal. Side bias in striatal lesions reached near-normal levels within 2 weeks, while rats with corticostriatal lesions remained impaired until week 14. AD values were decreased at 4 days and increased at 5 weeks post-surgery, with a subtype gradient: hypothalamic < striatal < corticostriatal. Intracerebral administration did not impact these readouts. After sample size calculation (18-147 rats per group according to the endpoint considered), we conclude that a therapeutic trial based on both readouts would be feasible only in the framework of a multicenter trial.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Animais , Terapia Baseada em Transplante de Células e Tecidos , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Ratos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/terapia
9.
Radiology ; 258(2): 496-504, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21163917

RESUMO

PURPOSE: To demonstrate the feasibility of combining in situ delivery of genetically modified cells into the rat kidney, to induce expression of a reporter gene under transcriptional control of a heat-inducible promoter activated with magnetic resonance (MR)-guided focused ultrasonography (US), and to demonstrate in vivo the local expression of the synthesized protein. MATERIALS AND METHODS: Experiments were conducted in agreement with the European Commission guidelines and directives of the French Research Ministry. C6 cells were genetically modified by incorporating the firefly luciferase (LucF) gene under transcriptional control of a heat-sensitive promoter (human heat shock protein 70B). Engineered cells were injected in the renal artery of a superficialized left kidney (15 rats). Two days later, intrarenal LucF expression was induced noninvasively by local hyperthermia in 15 renal locations in nine rats with focused US and was controlled with MR temperature imaging. Six hours after heating, LucF activity was detected in vivo with bioluminescence imaging. RESULTS: The genetically engineered C6 cell line was characterized in vitro for LucF expression related to the heating parameters. Changes in renal morphology and hemodynamic parameters as a result of rat kidney superficialization were not significant. Intrarenal temperature measurement at the focal point followed the scheduled temperature in 13 of 15 cases. On bioluminescence images, LucF activity was present only in heated regions. The level of LucF expression was also dependent on heating parameters. Substantial tissue damage was noted at histologic analysis in only the two cases in which temperature control was inadequate. CONCLUSION: A strategy combining cell delivery of a transgene and a thermosensitive promoter that can be locally activated with MR-guided focused US is able to induce in vivo gene expression controlled in space and time. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100767/-/DC1.


Assuntos
Expressão Gênica , Proteínas de Choque Térmico HSP70/metabolismo , Rim/citologia , Rim/diagnóstico por imagem , Luciferases/genética , Imagem por Ressonância Magnética Intervencionista , Transgenes , Análise de Variância , Animais , Estudos de Viabilidade , Genes Reporter , Rim/enzimologia , Masculino , Ratos , Ratos Wistar , Estatísticas não Paramétricas , Temperatura , Ultrassonografia
10.
Int J Radiat Oncol Biol Phys ; 107(2): 360-369, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32088292

RESUMO

PURPOSE: Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incident, highly collimated synchrotron beam into arrays of parallel microbeams depositing several hundred grays. It appears relevant to combine MRT with a conventional treatment course, preparing a treatment scheme for future patients in clinical trials. The efficiency of MRT delivered after several broad-beam (BB) fractions to palliate F98 brain tumors in rats in comparison with BB fractions alone was evaluated in this study. METHODS AND MATERIALS: Rats bearing 106 F98 cells implanted in the caudate nucleus were irradiated by 5 fractions in BB mode (3 × 6 Gy + 2 × 8 Gy BB) or by 2 boost fractions in MRT mode to a total of 5 fractions (3 × 6 Gy BB + MRT 2 × 8 Gy valley dose; peak dose 181 Gy [50/200 µm]). Tumor growth was evaluated in vivo by magnetic resonance imaging follow-up at T-1, T7, T12, T15, T20, and T25 days after radiation therapy and by histology and flow cytometry. RESULTS: MRT-boosted tumors displayed lower cell density and cell proliferation compared with BB-irradiated tumors. The MRT boost completely stopped tumor growth during ∼4 weeks and led to a significant increase in median survival time, whereas tumors treated with BB alone recurred within a few days after the last radiation fraction. CONCLUSIONS: The first evidence is presented that MRT, delivered as a boost of conventionally fractionated irradiation by orthovoltage broad x-ray beams, is feasible and more efficient than conventional radiation therapy alone.


Assuntos
Neoplasias Encefálicas/radioterapia , Fracionamento da Dose de Radiação , Glioblastoma/radioterapia , Glioma/radioterapia , Síncrotrons , Terapia por Raios X/instrumentação , Animais , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Ciclo Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia , Imageamento por Ressonância Magnética , Masculino , Ratos , Ratos Wistar , Carga Tumoral/efeitos da radiação
11.
Methods Mol Biol ; 1943: 347-363, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30838628

RESUMO

Noninvasive, real-time optical imaging methods are well suited to follow the in vivo distribution of nucleic acid nanocarriers, their dissociation and the resulting gene expression or inhibition. Indeed, most small animal imaging devices are performing bioluminescence and fluorescence measurements without moving the animal, allowing a simple, rapid, and cost-effective method of investigation of several parameters at a time, in longitudinal experiments that can last for days or weeks.Here we help the reader in choosing adapted near-infrared (NIR) fluorophores or pairs of fluorophores for FRET assays, imaging of reporter genes as well as nanocarriers for in vivo gene and siRNA delivery. In addition, we present the labeling methods of these macromolecules, and of their payload and the protocols to detect them using bioluminescence and NIR fluorescence imaging in mice.


Assuntos
Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Nanopartículas/química , Imagem Óptica/métodos , Animais , Peptídeos Penetradores de Células/química , Feminino , Técnicas de Transferência de Genes , Genes Reporter/genética , Microscopia Intravital/métodos , Medições Luminescentes/métodos , Camundongos , Camundongos Nus , Microscopia de Fluorescência/métodos , RNA Interferente Pequeno/genética , Coloração e Rotulagem/métodos
12.
Handb Exp Pharmacol ; (185 Pt 2): 225-43, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18626604

RESUMO

The interaction of ultrasound with tissue leads to radiation pressure, heat generation, and cavitation. These phenomena have been utilised for local gene delivery, transfection and control of expression. Specially designed nanocarriers or adapted ultrasound contrast agents can further enhance local delivery by: (1) increased permeability of cell membranes; (2) local release of genes. Biological carriers may also be used for local gene delivery. Stem cells and immune cells appear especially promising because of their homing capabilities to lesion sites. Imaging methods can be employed for pharmacodistribution and pharmacokinetics. MRI contrast agents can serve as non-invasive reporters on gene distribution when co-delivered with the gene. They can be used to label nanocarriers and cellular transport systems in gene therapy strategies such as those based on stem cells. Finally, ultrasound heating together with the use of a temperature sensitive promoter allows a local, physical, spatio-temporal control of transgene expression, in particular when combined with MRI temperature mapping for monitoring and even controlling ultrasound heating.


Assuntos
DNA/metabolismo , Regulação da Expressão Gênica , Terapia Genética , Transfecção/métodos , Transgenes , Terapia por Ultrassom , Ultrassom , Animais , Biomarcadores/metabolismo , Meios de Contraste/farmacocinética , Humanos , Imageamento por Ressonância Magnética , Nanopartículas
13.
Int J Radiat Oncol Biol Phys ; 98(5): 1174-1182, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28721902

RESUMO

PURPOSE: To compare the blood-brain barrier permeability changes induced by synchrotron microbeam radiation therapy (MRT, which relies on spatial fractionation of the incident x-ray beam into parallel micron-wide beams) with changes induced by a spatially uniform synchrotron x-ray radiation therapy. METHODS AND MATERIALS: Male rats bearing malignant intracranial F98 gliomas were randomized into 3 groups: untreated, exposed to MRT (peak and valley dose: 241 and 10.5 Gy, respectively), or exposed to broad beam irradiation (BB) delivered at comparable doses (ie, equivalent to MRT valley dose); both applied by 2 arrays, intersecting orthogonally the tumor region. Vessel permeability was monitored in vivo by magnetic resonance imaging 1 day before (T-1) and 1, 2, 7, and 14 days after treatment start. To determine whether physiologic parameters influence vascular permeability, we evaluated vessel integrity in the tumor area with different values for cerebral blood flow, blood volume, edema, and tissue oxygenation. RESULTS: Microbeam radiation therapy does not modify the vascular permeability of normal brain tissue. Microbeam radiation therapy-induced increase of tumor vascular permeability was detectable from T2 with a maximum at T7 after exposure, whereas BB enhanced vessel permeability only at T7. At this stage MRT was more efficient at increasing tumor vessel permeability (BB vs untreated: +19.1%; P=.0467; MRT vs untreated: +44.8%; P<.0001), and its effects lasted until T14 (MRT vs BB, +22.6%; P=.0199). We also showed that MRT was more efficient at targeting highly oxygenated (high blood volume and flow) and more proliferative parts of the tumor than BB. CONCLUSIONS: Microbeam radiation therapy-induced increased tumor vascular permeability is: (1) significantly greater; (2) earlier and more prolonged than that induced by BB irradiation, especially in highly proliferative tumor areas; and (3) targets all tumor areas discriminated by physiologic characteristics, including those not damaged by homogeneous irradiation.


Assuntos
Barreira Hematoencefálica/efeitos da radiação , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/radioterapia , Permeabilidade Capilar/efeitos da radiação , Glioma/irrigação sanguínea , Glioma/radioterapia , Síncrotrons , Animais , Volume Sanguíneo , Barreira Hematoencefálica/diagnóstico por imagem , Barreira Hematoencefálica/fisiopatologia , Encéfalo/irrigação sanguínea , Encéfalo/efeitos da radiação , Edema Encefálico/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Permeabilidade Capilar/fisiologia , Circulação Cerebrovascular/fisiologia , Fracionamento da Dose de Radiação , Glioma/diagnóstico por imagem , Glioma/patologia , Imageamento por Ressonância Magnética , Masculino , Método de Monte Carlo , Consumo de Oxigênio , Distribuição Aleatória , Ratos , Ratos Endogâmicos F344 , Fatores de Tempo , Carga Tumoral
14.
Stem Cells Int ; 2016: 6810562, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27274738

RESUMO

Stroke is an important health issue corresponding to the second cause of mortality and first cause of severe disability with no effective treatments after the first hours of onset. Regenerative approaches such as cell therapy provide an increase in endogenous brain structural plasticity but they are not enough to promote a complete recovery. Tissue engineering has recently aroused a major interesting development of biomaterials for use into the central nervous system. Many biomaterials have been engineered based on natural compounds, synthetic compounds, or a mix of both with the aim of providing polymers with specific properties. The mechanical properties of biomaterials can be exquisitely regulated forming polymers with different stiffness, modifiable physical state that polymerizes in situ, or small particles encapsulating cells or growth factors. The choice of biomaterial compounds should be adapted for the different applications, structure target, and delay of administration. Biocompatibilities with embedded cells and with the host tissue and biodegradation rate must be considerate. In this paper, we review the different applications of biomaterials combined with cell therapy in ischemic stroke and we explore specific features such as choice of biomaterial compounds and physical and mechanical properties concerning the recent studies in experimental stroke.

15.
Cell Transplant ; 25(12): 2157-2171, 2016 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-26924704

RESUMO

Stroke is the leading cause of disability in adults. Many current clinical trials use intravenous (IV) administration of human bone marrow-derived mesenchymal stem cells (BM-MSCs). This autologous graft requires a delay for ex vivo expansion of cells. We followed microvascular effects and mechanisms of action involved after an IV injection of human BM-MSCs (hBM-MSCs) at a subacute phase of stroke. Rats underwent a transient middle cerebral artery occlusion (MCAo) or a surgery without occlusion (sham) at day 0 (D0). At D8, rats received an IV injection of 3 million hBM-MSCs or PBS-glutamine. In a longitudinal behavioral follow-up, we showed delayed somatosensory and cognitive benefits 4 to 7 weeks after hBM-MSC injection. In a separate longitudinal in vivo magnetic resonance imaging (MRI) study, we observed an enhanced vascular density in the ischemic area 2 and 3 weeks after hBM-MSC injection. Histology and quantitative polymerase chain reaction (qPCR) revealed an overexpression of angiogenic factors such as Ang1 and transforming growth factor-1 (TGF-1) at D16 in hBM-MSC-treated MCAo rats compared to PBS-treated MCAo rats. Altogether, delayed IV injection of hBM-MSCs provides functional benefits and increases cerebral angiogenesis in the stroke lesion via a release of endogenous angiogenic factors enhancing the stabilization of newborn vessels. Enhanced angiogenesis could therefore be a means of improving functional recovery after stroke.


Assuntos
Células-Tronco Mesenquimais/citologia , Acidente Vascular Cerebral/patologia , Animais , Células da Medula Óssea/citologia , Isquemia Encefálica/patologia , Isquemia Encefálica/terapia , Terapia Baseada em Transplante de Células e Tecidos , Modelos Animais de Doenças , Humanos , Imuno-Histoquímica , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Imageamento por Ressonância Magnética , Masculino , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/fisiologia , Microvasos/metabolismo , Microvasos/patologia , Neovascularização Fisiológica/fisiologia , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/terapia , Fator de Crescimento Transformador beta2/metabolismo
16.
Brain Res Mol Brain Res ; 139(1): 184-91, 2005 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-15967539

RESUMO

F3/contactin is a neural adhesion molecule implicated in various physiological processes. In rat brain tissues, we cloned various mRNA with the same coding region but differing in 3' and 5'UTR. The 3'UTR presents two polyadenylation signals. At the 5' end, we identified two leader exons, multiple transcription initiation sites and splicing events, leading to at least 19 different 5'UTR. The F3/contactin rat gene differs from the mouse gene for two reasons: (1) it contains two additional untranslated exons that are alternatively spliced and (2) it lacks the homologue mouse untranslated exon 0.


Assuntos
Encéfalo/fisiologia , Moléculas de Adesão Celular Neuronais/genética , Polimorfismo Genético , RNA Mensageiro/metabolismo , Regiões não Traduzidas/genética , Processamento Alternativo , Animais , Sequência de Bases , Contactinas , Éxons , Camundongos , Dados de Sequência Molecular , Ratos , Alinhamento de Sequência , Sítio de Iniciação de Transcrição
17.
Oncotarget ; 6(16): 14669-86, 2015 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-26036640

RESUMO

We previously identified 1-(2,4-dimethoxyphenyl)-3-(1-methylindolyl) propenone (IPP51), a new chalcone derivative that is capable of inducing prometaphase arrest and subsequent apoptosis of bladder cancer cells. Here, we demonstrate that IPP51 selectively inhibits proliferation of tumor-derived cells versus normal non-tumor cells. IPP51 interfered with spindle formation and mitotic chromosome alignment. Accumulation of cyclin B1 and mitotic checkpoint proteins Bub1 and BubR1 on chromosomes in IPP51 treated cells indicated the activation of spindle-assembly checkpoint, which is consistent with the mitotic arrest. The antimitotic actions of other chalcones are often associated with microtubule disruption. Indeed, IPP51 inhibited tubulin polymerization in an in vitro assay with purified tubulin. In cells, IPP51 induced an increase in soluble tubulin. Furthermore, IPP51 inhibited in vitro capillary-like tube formation by endothelial cells, indicating that it has anti-angiogenic activity. Molecular docking showed that the indol group of IPP51 can be accommodated in the colchicine binding site of tubulin. This characteristic was confirmed by an in vitro competition assay demonstrating that IPP51 can compete for colchicine binding to soluble tubulin. Finally, in a human bladder xenograft mouse model, IPP51 inhibited tumor growth without signs of toxicity. Altogether, these findings suggest that IPP51 is an attractive new microtubule-targeting agent with potential chemotherapeutic value.


Assuntos
Microtúbulos/genética , Neoplasias da Bexiga Urinária/genética , Animais , Proliferação de Células , Humanos , Camundongos , Microtúbulos/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Methods Mol Biol ; 948: 49-65, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23070763

RESUMO

Noninvasive, real-time optical imaging methods are well suited to follow the in vivo distribution of nucleic acid nanocarriers, their dissociation, and the resulting gene expression or inhibition. Indeed, most small animal imaging devices perform bioluminescence and fluorescence measurements without moving the animal, allowing a simple, rapid, and cost-effective method of investigation of several parameters at a time, in longitudinal experiments that can last for days or weeks.Here we help the reader in choosing adapted near-infrared (NIR) fluorophores or pairs of fluorophores for Förster resonance energy transfer assays, imaging of reporter genes, as well as nanocarriers for in vivo gene and siRNA delivery. In addition, we present the labeling methods of these macromolecules and of their payload and the protocols to detect them using bioluminescence and NIR fluorescence imaging in mice.


Assuntos
DNA/metabolismo , Portadores de Fármacos/metabolismo , Raios Infravermelhos , Nanoestruturas , Imagem Óptica/métodos , RNA Interferente Pequeno/metabolismo , Animais , DNA/administração & dosagem , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Feminino , Corantes Fluorescentes/química , Óperon Lac/genética , Lipossomos , Medições Luminescentes , Camundongos , Fosfolipídeos/metabolismo , RNA Interferente Pequeno/administração & dosagem , Água/química
19.
Stem Cell Res Ther ; 4(2): 41, 2013 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-23628074

RESUMO

INTRODUCTION: Understanding the multiple biological functions played by human mesenchymal stem cells (hMSCs) as well as their development as therapeutics in regenerative medicine or in cancer treatment are major fields of research. Indeed, it has been established that hMSCs play a central role in the pathogenesis and progression of tumours, but their impact on tumour growth remains controversial. METHODS: In this study, we investigated the influence of hMSCs on the growth of pre-established tumours. We engrafted nude mice with luciferase-positive mouse adenocarcinoma cells (TSA-Luc+) to obtain subcutaneous or lung tumours. When tumour presence was confirmed by non-invasive bioluminescence imaging, hMSCs were injected into the periphery of the SC tumours or delivered by systemic intravenous injection in mice bearing either SC tumours or lung metastasis. RESULTS: Regardless of the tumour model and mode of hMSC injection, hMSC administration was always associated with decreased tumour growth due to an inhibition of tumour cell proliferation, likely resulting from deep modifications of the tumour angiogenesis. Indeed, we established that although hMSCs can induce the formation of new blood vessels in a non-tumoural cellulose sponge model in mice, they do not modify the overall amount of haemoglobin delivered into the SC tumours or lung metastasis. We observed that these tumour vessels were reduced in number but were longer. CONCLUSIONS: Our results suggest that hMSCs injection decreased solid tumour growth in mice and modified tumour vasculature, which confirms hMSCs could be interesting to use for the treatment of pre-established tumours.


Assuntos
Neoplasias Pulmonares/patologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Neovascularização Fisiológica , Actinas/metabolismo , Animais , Células da Medula Óssea/citologia , Linhagem Celular Tumoral , Humanos , Injeções Intravenosas , Injeções Subcutâneas , Antígeno Ki-67/metabolismo , Neoplasias Pulmonares/metabolismo , Imageamento por Ressonância Magnética , Camundongos , Camundongos Nus , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo
20.
J Cell Biol ; 202(3): 545-61, 2013 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-23918940

RESUMO

The endothelial CCM complex regulates blood vessel stability and permeability. Loss-of-function mutations in CCM genes are responsible for human cerebral cavernous malformations (CCMs), which are characterized by clusters of hemorrhagic dilated capillaries composed of endothelium lacking mural cells and altered sub-endothelial extracellular matrix (ECM). Association of the CCM1/2 complex with ICAP-1, an inhibitor of ß1 integrin, prompted us to investigate whether the CCM complex interferes with integrin signaling. We demonstrate that CCM1/2 loss resulted in ICAP-1 destabilization, which increased ß1 integrin activation and led to increased RhoA-dependent contractility. The resulting abnormal distribution of forces led to aberrant ECM remodeling around lesions of CCM1- and CCM2-deficient mice. ICAP-1-deficient vessels displayed similar defects. We demonstrate that a positive feedback loop between the aberrant ECM and internal cellular tension led to decreased endothelial barrier function. Our data support that up-regulation of ß1 integrin activation participates in the progression of CCM lesions by destabilizing intercellular junctions through increased cell contractility and aberrant ECM remodeling.


Assuntos
Fibronectinas/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Integrina beta1/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Adesão Celular , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Proteína KRIT1 , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/deficiência , Modelos Biológicos , Proteínas Proto-Oncogênicas/deficiência
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