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1.
Chemistry ; 26(65): 15035-15044, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32633095

RESUMO

Novel 6-alkyl- and 6-alkenyl-3-fluoro-2-pyridinaldoximes have been synthesised by using a mild and efficient chemoselective hydrogenation of 6-alkynyl-3-fluoro-2-pyridinaldoxime scaffolds, without altering the reducible, unprotected, sensitive oxime functionality and the C-F bond. These novel 6-alkyl-3-fluoro-2-pyridinaldoximes may find medicinal application as antidotes to organophosphate poisoning. Indeed, one low-molecular-weight compound exhibited increased affinity for sarin-inhibited acetylcholinesterase (hAChE) and greater reactivation efficiency or resurrection for sarin-inhibited hAChE, compared with those of 2-pyridinaldoxime (2-PAM) and 1-({[4-(aminocarbonyl)pyridinio]methoxy}methyl)-2-[(hydroxyimino)methyl]pyridinium chloride (HI-6), two pyridinium salts currently used as antidote by several countries. In addition, the uncharged 3-fluorinated bifunctional hybrid showed increased in vitro blood-brain barrier permeability compared with those of 2-PAM, HI-6 and obidoxime. These promising features of novel low-molecular-weight alkylfluoropyridinaldoxime open up a new era for the design, synthesis and discovery of central non-quaternary broad spectrum reactivators for organophosphate-inhibited cholinesterases.


Assuntos
Barreira Hematoencefálica , Acetilcolinesterase/metabolismo , Barreira Hematoencefálica/metabolismo , Inibidores da Colinesterase , Reativadores da Colinesterase , Humanos , Hidrogenação , Oximas , Permeabilidade , Compostos de Piridínio , Sarina
2.
Mol Pharm ; 15(7): 2528-2538, 2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-29874916

RESUMO

Variability in drug response to lithium (Li+) is poorly understood and significant, as only 40% of patients with bipolar disorder highly respond to Li+. Li+ can be transported by sodium (Na+) transporters in kidney tubules or red blood cells, but its transport has not been investigated at the blood-brain barrier (BBB). Inhibition and/or transcriptomic strategies for Na+ transporters such as NHE (SLC9), NBC (SLC4), and NKCC (SLC12) were used to assess their role on Li+ transport in human brain endothelial cells. Na+-free buffer was also used to examine Na+/Li+ countertransport (NLCT) activity. The BBB permeability of Li+ evaluated in the rat was 2% that of diazepam, a high passive diffusion lipophilic compound. Gene expression of several Na+ transporters was determined in hCMEC/D3 cells, human hematopoietic stem-cell-derived BBB models (HBLEC), and human primary brain microvascular endothelial cells (hPBMECs) and showed the following rank order with close expression profile: NHE1 > NKCC1 > NHE5 > NBCn1, while NHE2-4, NBCn2, and NBCe1-2 were barely detected. Li+ influx in hCMEC/D3 cells was increased in Na+-free buffer by 3.3-fold, while depletion of chloride or bicarbonate had no effect. DMA (NHE inhibitor), DIDS (anionic carriers inhibitor), and bumetanide (NKCC inhibitor) decreased Li+ uptake significantly in hCMEC/D3 by 52, 51, and 47%, respectively, while S0859 (NBC inhibitor) increased Li+ influx 2.3-fold. Zoniporide (NHE1 inhibitor) and siRNA against NHE1 had no effect on Li+ influx in hCMEC/D3 cells. Our study shows that NHE1 and/or NHE5, NBCn1, and NKCC1 may play a significant role in the transport of Li+ through the plasma membrane of brain endothelial cells.


Assuntos
Antimaníacos/farmacologia , Barreira Hematoencefálica/metabolismo , Células Endoteliais/metabolismo , Compostos de Lítio/farmacologia , Proteínas Carreadoras de Solutos/metabolismo , Animais , Antimaníacos/uso terapêutico , Transtorno Bipolar/tratamento farmacológico , Barreira Hematoencefálica/citologia , Barreira Hematoencefálica/efeitos dos fármacos , Permeabilidade Capilar/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Células Endoteliais/efeitos dos fármacos , Células HEK293 , Humanos , Compostos de Lítio/uso terapêutico , Masculino , Microvasos/citologia , Microvasos/efeitos dos fármacos , Microvasos/metabolismo , Cultura Primária de Células , Ratos , Ratos Sprague-Dawley , Sódio/metabolismo , Proteínas Carreadoras de Solutos/antagonistas & inibidores
3.
Lab Invest ; 96(5): 588-98, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26901835

RESUMO

Although brain metastases are the most common brain tumors in adults, there are few treatment options in this setting. To colonize the brain, circulating tumor cells must cross the blood-brain barrier (BBB), which is situated within specialized, restrictive microvascular endothelium. Understanding how cancer cells manage to transmigrate through the BBB might enable this process to be prevented. In vitro models are dedicated tools for characterizing the cellular and molecular mechanisms that underlie transendothelial migration process, as long as they accurately mimic the brain endothelium's in vivo characteristics. The objective of the present study was to adapt an existing in vitro model of the human BBB for use in studying cancer cell transmigration. The model is based on the coculture of endothelial cells (ECs, derived from cord blood hematopoietic stem cells) and brain pericytes. To allow the migration of cancer cells into the lower compartment, our model had to be transposed onto inserts with a larger pore size. However, we encountered a problem when culturing ECs on large (3-µm)-pore inserts: the cells crossed the membrane and formed a non-physiological second layer on the lower face of the insert. Using 3-µm-pore inserts (in a 12-well plate format), we report here on a method that enables the maintenance of a single monolayer of ECs on the insert's upper face only. Under these chosen conditions, the ECs exhibited typical BBB properties found in the original model (including restricted paracellular permeability and the expression of continuous tight junctions). This modified in vitro model of the human BBB enabled us to investigate the migratory potential of the MDA-MB-231 cell line (derived from highly metastatic human breast cancer cells). Last, the results obtained were compared with the rate of transmigration through endothelia with no BBB features.


Assuntos
Barreira Hematoencefálica/fisiologia , Células Neoplásicas Circulantes/patologia , Migração Transendotelial e Transepitelial/fisiologia , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Técnicas de Cocultura/instrumentação , Técnicas de Cocultura/métodos , Endotélio Vascular/fisiologia , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Modelos Biológicos , Pericitos/fisiologia , Porosidade
4.
Subcell Biochem ; 76: 125-51, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26219710

RESUMO

The microvessels of the brain represent around 3-4 % of the brain compartment but constitute the most important length (400 miles) and surface of exchange (20 m(2)) between the blood and the parenchyma of brain. Under influence of surrounding tissues, the brain microvessel endothelium expresses a specific phenotype that regulates and restricts the entry of compounds and cells from blood to brain, and defined the so-called blood-brain barrier (BBB). Evidences that alkaline phosphatase (AP) is a characteristic feature of the BBB phenotype that allows differentiating capillary endothelial cells from brain to those of the periphery have rapidly emerge. Thenceforth, AP has been rapidly used as a biomarker of the blood-brain barrier phenotype. In fact, brain capillary endothelial cells (BCECs) express exclusively tissue non-specific alkaline phosphatase (TNAP). There are several lines of evidence in favour of an important role for TNAP in brain function. TNAP is thought to be responsible for the control of transport of some compounds across the plasma membrane of the BCECs. Here, we report that levamisole-mediated inhibition of TNAP provokes an increase of the permeability to Lucifer Yellow of the endothelial monolayer. Moreover, we illustrate the disruption of the cytoskeleton organization. Interestingly, all observed effects were reversible 24 h after levamisole removal and correlated with the return of a full activity of the TNAP. This reversible effect remains to be studied in details to evaluate the potentiality of a levamisole treatment to enhance the entry of drugs in the brain parenchyma.


Assuntos
Fosfatase Alcalina/fisiologia , Vasos Sanguíneos/enzimologia , Encéfalo/irrigação sanguínea , Animais , Biomarcadores/metabolismo , Vasos Sanguíneos/metabolismo , Barreira Hematoencefálica/enzimologia , Barreira Hematoencefálica/metabolismo , Encéfalo/enzimologia , Encéfalo/metabolismo , Permeabilidade Capilar/genética , Circulação Cerebrovascular/genética , Humanos
5.
Int J Mol Sci ; 17(8)2016 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-27529215

RESUMO

The ST6GALNAC5 gene that encodes an α2,6-sialyltransferase involved in the biosynthesis of α-series gangliosides, was previously identified as one of the genes that mediate breast cancer metastasis to the brain. We have shown that the expression of ST6GALNAC5 in MDA-MB-231 breast cancer cells resulted in the expression of GD1α ganglioside at the cell surface. By using a human blood-brain barrier in vitro model recently developed, consisting in CD34⁺ derived endothelial cells co-cultivated with pericytes, we show that ST6GALNAC5 expression decreased the interactions between the breast cancer cells and the human blood-brain barrier.


Assuntos
Barreira Hematoencefálica/metabolismo , Neoplasias da Mama/metabolismo , Sialiltransferases/metabolismo , Animais , Antígenos CD34/metabolismo , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Feminino , Gangliosídeo G(M1)/análogos & derivados , Gangliosídeo G(M1)/metabolismo , Humanos , Camundongos , Pericitos/metabolismo , Sialiltransferases/genética
6.
Proteomics ; 13(7): 1185-99, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23436736

RESUMO

In the neurovascular unit, brain microvascular endothelial cells develop characteristic barrier features that control the molecular exchanges between the blood and the brain. These characteristics are partially or totally lost when the cells are isolated for use in in vitro blood-brain barrier (BBB) models. Hence, the re-induction of barrier properties is crucial for the relevance of BBB models. Although the role of astrocyte promiscuity is well established, the molecular mechanisms of re-induction remain largely unknown. Here, we used a DIGE-based proteomics approach to study endothelial cellular proteins showing significant quantitative variations after BBB re-induction. We confirm that quantitative changes mainly concern proteins involved in cell structure and motility. Furthermore, we describe the possible involvement of the asymmetric dimethylarginine pathway in the BBB phenotype re-induction process and we discuss asymmetric dimethylarginine's potential role in regulating endothelial function (in addition to its role as a by-product of protein modification). Our results also suggest that the intracellular redox potential is lower in the in vitro brain capillary endothelial cells displaying re-induced BBB functions than in cells with limited BBB functions.


Assuntos
Barreira Hematoencefálica/metabolismo , Eletroforese em Gel Bidimensional/métodos , Células Endoteliais/metabolismo , Neuroglia/metabolismo , Animais , Arginina/análogos & derivados , Barreira Hematoencefálica/citologia , Bovinos , Meios de Cultura , Immunoblotting , Fenótipo , Ratos , Reprodutibilidade dos Testes
7.
Methods Mol Biol ; 2492: 277-288, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35733051

RESUMO

Studying the mechanisms of breast cancer cells in brain metastases is challenging, considering the high specificity of the blood-brain barrier (BBB) with whom breast cancer cells have to interact and cross in order to reach the brain parenchyma. While numerous in vitro BBB models are available, the setting of the model and phenotype of the endothelial cells (ECs) of the BBB model are essential to obtain relevant results.In this chapter, we describe a method to establish a human in vitro BBB model to study adhesion of breast cancer cells and the adaptation of the method for trans-endothelial migration assay keeping the appropriate BBB phenotype of the ECs.


Assuntos
Neoplasias Encefálicas , Neoplasias da Mama , Transporte Biológico , Barreira Hematoencefálica , Encéfalo/patologia , Neoplasias Encefálicas/genética , Neoplasias da Mama/patologia , Células Endoteliais , Feminino , Humanos
8.
Int J Pharm ; 621: 121780, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35504427

RESUMO

Treatment for CNS related diseases are limited by the difficulty of the drugs to cross the blood-brain barrier (BBB). The functionalization of polymeric nanoparticles (NPs) coated with the surfactants polysorbate 80 (PS80) and poloxamer 188 (P188), have shown promising results as drugs carriers are able to cross the BBB on animal models. In this study, poly(lactide-co-glycolide) (PLGA) NPs coated with PS80 and P188, labelled with a fluorescent dye were tested on human pre-clinical in vitro model to evaluate and compare their uptake profiles, mechanisms of transport and crossing over human brain-like endothelial cells (BLECs) mimicking the human BBB. In addition, these NPs were produced using a method facilitating their reproducible production at high scale, the MicroJet reactor® technology. Results showed that both formulations were biocompatible and able to be internalized within the BLECs in different uptake profiles depending on their coating: P188 NP showed higher internalization capacity than PS80 NP. Both NPs uptakes were ATP-dependent, following more than one endocytosis pathway with colocalization in the early endosomes, ending with a NPs release in the brain compartment. Thus, both surfactant-coated PLGA NPs are interesting formulations for delivery to the brain through the BBB, presenting different uptake profiles.


Assuntos
Nanopartículas , Surfactantes Pulmonares , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Portadores de Fármacos/metabolismo , Células Endoteliais/metabolismo , Excipientes/metabolismo , Humanos , Poloxâmero/metabolismo , Polissorbatos , Surfactantes Pulmonares/metabolismo , Tensoativos/metabolismo
9.
Cells ; 11(24)2022 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-36552728

RESUMO

We previously developed an in vitro model of the human blood-brain barrier (BBB) based on the use of endothelial cells derived from CD34+-hematopoietic stem cells and cultured with brain pericytes. The purpose of the present study was to provide information on the protein expression levels of the transporters, receptors, tight junction/adherence junction molecules, and transporter-associated molecules of human brain-like endothelial cells (hBLECs). The absolute protein expression levels were determined by liquid chromatography-mass spectrometry-based quantitative targeted absolute proteomics and compared with those from human brain microvessels (hBMVs). The protein levels of CD144, CD147, MRP4, Annexin A6 and caveolin-1 showed more than 3-fold abundance in hBLECs, those of MCT1, Connexin 43, TfR1, and claudin-5 showed less than 3-fold differences, and the protein levels of other drug efflux transporters and nutrient transporters were less represented in hBLECs than in hBMVs. It is noteworthy that BCRP was more expressed than MDR1 in hBLECs, as this was the case for hBMVs. These results suggest that transports mediated by MCT1, TfR1, and claudin-5-related tight junction function reflect the in vivo BBB situation. The present study provided a better characterization of hBLECs and clarified the equivalence of the transport characteristics between in vitro BBB models and in vivo BBB models using LC-MS/MS-based protein quantification.


Assuntos
Barreira Hematoencefálica , Células Endoteliais , Humanos , Barreira Hematoencefálica/metabolismo , Células Endoteliais/metabolismo , Cromatografia Líquida , Proteômica/métodos , Claudina-5/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Espectrometria de Massas em Tandem/métodos , Proteínas de Neoplasias/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Células-Tronco Hematopoéticas/metabolismo
10.
J Med Chem ; 65(6): 4649-4666, 2022 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-35255209

RESUMO

Recent events demonstrated that organophosphorus nerve agents are a serious threat for civilian and military populations. The current therapy includes a pyridinium aldoxime reactivator to restore the enzymatic activity of acetylcholinesterase located in the central nervous system and neuro-muscular junctions. One major drawback of these charged acetylcholinesterase reactivators is their poor ability to cross the blood-brain barrier. In this study, we propose to evaluate glucoconjugated oximes devoid of permanent charge as potential central nervous system reactivators. We determined their in vitro reactivation efficacy on inhibited human acetylcholinesterase, the crystal structure of two compounds in complex with the enzyme, their protective index on intoxicated mice, and their pharmacokinetics. We then evaluated their endothelial permeability coefficients with a human in vitro model. This study shed light on the structural restrains of new sugar oximes designed to reach the central nervous system through the glucose transporter located at the blood-brain barrier.


Assuntos
Intoxicação por Organofosfatos , Acetilcolinesterase , Animais , Antídotos/farmacologia , Antídotos/uso terapêutico , Inibidores da Colinesterase/farmacologia , Camundongos , Intoxicação por Organofosfatos/tratamento farmacológico , Compostos Organofosforados/farmacologia , Oximas/química , Oximas/farmacologia , Oximas/uso terapêutico , Açúcares
11.
Pharmaceutics ; 13(6)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208550

RESUMO

Central nervous system (CNS) diseases are one of the top causes of death worldwide. As there is a difficulty of drug penetration into the brain due to the blood-brain barrier (BBB), many CNS drugs treatments fail in clinical trials. Hence, there is a need to develop effective CNS drugs following strategies for delivery to the brain by better selecting them as early as possible during the drug discovery process. The use of in vitro BBB models has proved useful to evaluate the impact of drugs/compounds toxicity, BBB permeation rates and molecular transport mechanisms within the brain cells in academic research and early-stage drug discovery. However, these studies that require biological material (animal brain or human cells) are time-consuming and involve costly amounts of materials and plastic wastes due to the format of the models. Hence, to adapt to the high yields needed in early-stage drug discoveries for compound screenings, a patented well-established human in vitro BBB model was miniaturized and automated into a 96-well format. This replicate met all the BBB model reliability criteria to get predictive results, allowing a significant reduction in biological materials, waste and a higher screening capacity for being extensively used during early-stage drug discovery studies.

12.
J Vis Exp ; (177)2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34927613

RESUMO

The delivery of drugs to the brain remains a challenge due to the blood-brain barrier's (BBB) highly specific and restrictive properties, which controls and restrict access to the brain parenchyma. However, with the development of nanotechnologies, large panels of new nanomaterials were developed to improve drug delivery, highlighting the need for reliable in vitro microsystems to predict brain penetration in the frame of preclinical assays. Here is a straightforward method to set up a microphysiological system to model the BBB using solely human cells. In its configuration, the model consists of a triple culture including brain-like endothelial cells (BLECs), pericytes, and astrocytes, the three main BBB cellular actors necessary to induce and regulate the BBB properties in a more physiological manner without the requirement of tightening compounds. The model developed in a 12-well plate format, ready after 6 days of triple culture, is characterized in physical properties, gene, and protein expressions and used for polymeric nanogel transport measurement. The model can be used for an extensive range of experiments in healthy and pathological conditions and represents a valuable tool for preclinical assessments of molecule and particle transport, as well as inter-and intracellular trafficking.


Assuntos
Barreira Hematoencefálica , Células Endoteliais , Astrócitos , Transporte Biológico/fisiologia , Barreira Hematoencefálica/metabolismo , Técnicas de Cocultura , Células Endoteliais/metabolismo , Humanos , Pericitos/metabolismo
13.
Nat Rev Drug Discov ; 6(8): 650-61, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17667956

RESUMO

The market for neuropharmaceuticals is potentially one of the largest sectors of the global pharmaceutical market owing to the increase in average life expectancy and the fact that many neurological disorders have been largely refractory to pharmacotherapy. The brain is a delicate organ that can efficiently protect itself from harmful compounds and precisely regulate its microenvironment. Unfortunately, the same mechanisms can also prove to be formidable hurdles in drug development. An improved understanding of the regulatory interfaces that exist between blood and brain may provide novel and more effective strategies to treat neurological disorders.


Assuntos
Barreira Hematoencefálica/metabolismo , Desenho de Fármacos , Modelos Biológicos , Animais , Barreira Hematoencefálica/citologia , Ensaios Clínicos como Assunto/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Neurofarmacologia/métodos , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/química
14.
Fluids Barriers CNS ; 17(1): 37, 2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32487241

RESUMO

BACKGROUND: Pediatric diffuse intrinsic pontine glioma (DIPG) represents one of the most devastating and lethal brain tumors in children with a median survival of 12 months. The high mortality rate can be explained by the ineligibility of patients to surgical resection due to the diffuse growth pattern and midline localization of the tumor. While the therapeutic strategies are unfortunately palliative, the blood-brain barrier (BBB) is suspected to be responsible for the treatment inefficiency. Located at the brain capillary endothelial cells (ECs), the BBB has specific properties to tightly control and restrict the access of molecules to the brain parenchyma including chemotherapeutic compounds. However, these BBB specific properties can be modified in a pathological environment, thus modulating brain exposure to therapeutic drugs. Hence, this study aimed at developing a syngeneic human blood-brain tumor barrier model to understand how the presence of DIPG impacts the structure and function of brain capillary ECs. METHODS: A human syngeneic in vitro BBB model consisting of a triple culture of human (ECs) (differentiated from CD34+-stem cells), pericytes and astrocytes was developed. Once validated in terms of BBB phenotype, this model was adapted to develop a blood-brain tumor barrier (BBTB) model specific to pediatric DIPG by replacing the astrocytes by DIPG-007, -013 and -014 cells. The physical and metabolic properties of the BBTB ECs were analyzed and compared to the BBB ECs. The permeability of both models to chemotherapeutic compounds was evaluated. RESULTS: In line with clinical observation, the integrity of the BBTB ECs remained intact until 7 days of incubation. Both transcriptional expression and activity of efflux transporters were not strongly modified by the presence of DIPG. The permeability of ECs to the chemotherapeutic drugs temozolomide and panobinostat was not affected by the DIPG environment. CONCLUSIONS: This original human BBTB model allows a better understanding of the influence of DIPG on the BBTB ECs phenotype. Our data reveal that the chemoresistance described for DIPG does not come from the development of a "super BBB". These results, validated by the absence of modification of drug transport through the BBTB ECs, point out the importance of understanding the implication of the different protagonists in the pathology to have a chance to significantly improve treatment efficiency.


Assuntos
Antineoplásicos/farmacologia , Barreira Hematoencefálica , Neoplasias Encefálicas , Glioma Pontino Intrínseco Difuso , Resistencia a Medicamentos Antineoplásicos , Modelos Neurológicos , Barreira Hematoencefálica/efeitos dos fármacos , Neoplasias Encefálicas/tratamento farmacológico , Células Cultivadas , Glioma Pontino Intrínseco Difuso/tratamento farmacológico , Células Endoteliais , Humanos , Panobinostat/farmacologia , Temozolomida/farmacologia
15.
Biomolecules ; 10(6)2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32512884

RESUMO

(1) Background: Human exposure to organophosphorus compounds employed as pesticides or as chemical warfare agents induces deleterious effects due to cholinesterase inhibition. One therapeutic approach is the reactivation of inhibited acetylcholinesterase by oximes. While currently available oximes are unable to reach the central nervous system to reactivate cholinesterases or to display a wide spectrum of action against the variety of organophosphorus compounds, we aim to identify new reactivators without such drawbacks. (2) Methods: This study gathers an exhaustive work to assess in vitro and in vivo efficacy, and toxicity of a hybrid tetrahydroacridine pyridinaldoxime reactivator, KM297, compared to pralidoxime. (3) Results: Blood-brain barrier crossing assay carried out on a human in vitro model established that KM297 has an endothelial permeability coefficient twice that of pralidoxime. It also presents higher cytotoxicity, particularly on bone marrow-derived cells. Its strong cholinesterase inhibition potency seems to be correlated to its low protective efficacy in mice exposed to paraoxon. Ventilatory monitoring of KM297-treated mice by double-chamber plethysmography shows toxic effects at the selected therapeutic dose. This breathing assessment could help define the No Observed Adverse Effect Level (NOAEL) dose of new oximes which would have a maximum therapeutic effect without any toxic side effects.


Assuntos
Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/farmacologia , Compostos de Pralidoxima/farmacologia , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Inibidores da Colinesterase/administração & dosagem , Inibidores da Colinesterase/química , Relação Dose-Resposta a Droga , Humanos , Injeções Intraperitoneais , Masculino , Camundongos , Estrutura Molecular , Compostos de Pralidoxima/química , Proteínas Recombinantes/metabolismo
16.
Stem Cell Reports ; 13(4): 599-611, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31495714

RESUMO

The derivation of human brain capillary endothelial cells is of utmost importance for drug discovery programs focusing on diseases of the central nervous system. Here, we describe a two-step differentiation protocol to derive brain capillary-like endothelial cells from human pluripotent stem cells. The cells were initially differentiated into endothelial progenitor cells followed by specification into a brain capillary-like endothelial cell phenotype using a protocol that combined the induction, in a time-dependent manner, of VEGF, Wnt3a, and retinoic acid signaling pathways and the use of fibronectin as the extracellular matrix. The brain capillary-like endothelial cells displayed a permeability to lucifer yellow of 1 × 10-3 cm/min, a transendothelial electrical resistance value of 60 Ω cm2 and were able to generate a continuous monolayer of cells expressing ZO-1 and CLAUDIN-5 but moderate expression of P-glycoprotein. Further maturation of these cells required coculture with pericytes. The study presented here opens a new approach for the study of soluble and non-soluble factors in the specification of endothelial progenitor cells into brain capillary-like endothelial cells.


Assuntos
Diferenciação Celular , Células Progenitoras Endoteliais/citologia , Células-Tronco Pluripotentes/citologia , Biomarcadores , Barreira Hematoencefálica/citologia , Células Cultivadas , Células Progenitoras Endoteliais/metabolismo , Endotélio Vascular/citologia , Matriz Extracelular/metabolismo , Humanos , Imunofenotipagem , Células-Tronco Pluripotentes/metabolismo
17.
Toxicol In Vitro ; 22(3): 799-811, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18280105

RESUMO

There is a growing interest to use in vitro BBB cell assays in early safety assessment of compounds. By modifying a well-validated co-culture model of brain capillary endothelial and glial cells, developed by Dehouck et al. [Dehouck, M.P., Meresse, S., Delorme, P., Fruchart, J.C., Cecchelli, R., 1990. An easier, reproducible, and mass-production method to study the blood-brain barrier in vitro. Journal of Neurochemistry 54 (5), 1798-1801], it has been possible to develop a new in vitro BBB system suitable for high throughput screening (HTS). In addition, this new procedure substantially reduces the use of experimental animals and considerably facilitates the process of obtaining a functional in vitro BBB model. The model is ready to use after only 4 days of culture and then shows the typical expression and localization of tight junction proteins. The function of the P-glycoprotein and the transcriptional expression of other efflux transporters such as MRP 1, 4 and 5 have been demonstrated. In addition, the model produces a good in vitro/in vivo correlation for 10 compounds (R2=0.81). Furthermore, studies were undertaken within the European ACuteTox consortium with the objective to assess BBB toxicity and make risk assessments of potentially toxic compounds according to their predicted ability to reach the CNS compartment. These investigations demonstrated that the results produced in the HTS BBB model were similar to the standard co-culture model.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Subfamília B de Transportador de Cassetes de Ligação de ATP/biossíntese , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Animais , Western Blotting , Proteínas de Transporte/metabolismo , Bovinos , Células Cultivadas , Química Farmacêutica , Interpretação Estatística de Dados , Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Microscopia de Fluorescência , Permeabilidade/efeitos dos fármacos , Preparações Farmacêuticas/metabolismo , RNA/biossíntese , RNA/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Junções Íntimas/efeitos dos fármacos
18.
J Control Release ; 284: 57-72, 2018 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-29902485

RESUMO

Stimulation of adult neurogenesis by targeting the endogenous neural stem cells (NSCs), located in hippocampus and subventricular zone (SVZ), with nanoformulations has been proposed for brain repair in cases of neurodegenerative diseases. Unfortunately, it is relatively unknown the nanoformulation properties to facilitate their accumulation in the neurogenic niches after intravenous injection. Here, we have screened different gold-based formulations having variable morphology, surface chemistry and responsiveness to light for their capacity to cross the blood brain barrier (BBB) and accumulate preferentially in the neurogenic niches. Results obtained in a human in vitro BBB model showed that gold nanoparticles (Au NPs) and gold nanorods (Au NRs) conjugated with medium density of transferrin (Tf) peptides (i.e. between 169 and 230 peptides per NP) crossed more efficiently the BBB than the remaining formulations. This is due to a relatively lower avidity of these formulations to Tf receptor (TfR) and lower accumulation in the lysosomes, as compared to the other formulations. We further show that the near infrared light (NIR) irradiation of Au NRs, under a certain concentration and at specific cell culture time, lead to the opening of the BBB. Finally, we demonstrate that Au NRs conjugated with Tf administered intravenously in mice and activated by NIR had the highest accumulation in the neurogenic niches. Our results open the possibility of targeting more effectively the neurogenic niches by controlling the properties of the nanoformulations.


Assuntos
Encéfalo/metabolismo , Portadores de Fármacos/metabolismo , Ouro/metabolismo , Nanopartículas/metabolismo , Transferrina/metabolismo , Animais , Transporte Biológico , Barreira Hematoencefálica/metabolismo , Linhagem Celular , Portadores de Fármacos/análise , Ouro/análise , Humanos , Nanopartículas Metálicas/química , Camundongos , Nanopartículas/análise , Nanotubos/análise , Neurogênese , Transferrina/análise
19.
Microbes Infect ; 8(1): 1-9, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15914062

RESUMO

Mycobacterium tuberculosis, the etiologic agent of tuberculosis, adheres to, invades and multiplies in both professional phagocytes and epithelial cells. Adherence to epithelial cells is predominantly mediated by the 28-kDa heparin-binding haemagglutinin adhesin (HBHA), which is also required for the extrapulmonary dissemination of the bacilli. To study the cellular mechanisms that might result in HBHA-mediated extrapulmonary dissemination, we used a transwell model of cellular barrier and fluorescence microscopy and found that HBHA induces a reorganization of the actin filament network in confluent endothelial cells, but does not affect the tight junctions that link them. When coupled to colloidal gold particles, HBHA-mediated a rapid attachment of the particles to the membrane of human laryngeal epithelial cells (non polarized HEp-2 cells) and human type II pneumocytes (polarized A-549 pneumocytes). After attachment, the particles were internalized in membrane-bound vacuoles that migrated across the polarized pneumocytes to reach the basal side. Attachment of the HBHA-coated particles was not observed when the epithelial cells were pretreated with heparinase III, a lyase that specifically cleaves the heparan sulfate chains borne by the proteoglycans. Furthermore, no binding was observed when the gold particles were coated with HBHA lacking its C-terminal heparin-binding domain. These observations indicate that HBHA induces receptor-mediated endocytosis through the recognition of heparan sulfate-containing proteoglycans by the heparin-binding domain of the adhesin. In addition, the transcellular migration of the endocytic vacuoles containing HBHA-coated particles suggests that HBHA induces epithelial transcytosis, which may represent a macrophage-independent extrapulmonary dissemination mechanism leading to systemic infection by M. tuberculosis.


Assuntos
Endocitose/efeitos dos fármacos , Lectinas/farmacologia , Mycobacterium tuberculosis , Proteoglicanas/metabolismo , Junções Íntimas/efeitos dos fármacos , Actinas/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Bovinos , Linhagem Celular , Citoesqueleto/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/ultraestrutura , Humanos , Neuroglia/metabolismo , Ratos , Receptores de Superfície Celular/metabolismo , Junções Íntimas/fisiologia , Vesículas Transportadoras/metabolismo
20.
PLoS One ; 11(3): e0151155, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26958843

RESUMO

Around 7-17% of metastatic breast cancer patients will develop brain metastases, associated with a poor prognosis. To reach the brain parenchyma, cancer cells need to cross the highly restrictive endothelium of the Blood-Brain Barrier (BBB). As treatments for brain metastases are mostly inefficient, preventing cancer cells to reach the brain could provide a relevant and important strategy. For that purpose an in vitro approach is required to identify cellular and molecular interaction mechanisms between breast cancer cells and BBB endothelium, notably at the early steps of the interaction. However, while numerous studies are performed with in vitro models, the heterogeneity and the quality of BBB models used is a limitation to the extrapolation of the obtained results to in vivo context, showing that the choice of a model that fulfills the biological BBB characteristics is essential. Therefore, we compared pre-established and currently used in vitro models from different origins (bovine, mice, human) in order to define the most appropriate tool to study interactions between breast cancer cells and the BBB. On each model, the BBB properties and the adhesion capacities of breast cancer cell lines were evaluated. As endothelial cells represent the physical restriction site of the BBB, all the models consisted of endothelial cells from animal or human origins. Among these models, only the in vitro BBB model derived from human stem cells both displayed BBB properties and allowed measurement of meaningful different interaction capacities of the cancer cell lines. Importantly, the measured adhesion and transmigration were found to be in accordance with the cancer cell lines molecular subtypes. In addition, at a molecular level, the inhibition of ganglioside biosynthesis highlights the potential role of glycosylation in breast cancer cells adhesion capacities.


Assuntos
Barreira Hematoencefálica/citologia , Neoplasias da Mama/patologia , Animais , Antígenos CD34/metabolismo , Bovinos , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Células Cultivadas , Feminino , Sangue Fetal/citologia , Humanos , Camundongos , Neuroglia/citologia , Neuroglia/metabolismo , Pericitos/citologia , Pericitos/metabolismo , Ratos
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