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1.
Fluids Barriers CNS ; 17(1): 10, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32036786

RESUMO

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a neurological disorder characterised by raised cerebrospinal fluid (CSF) pressure in the absence of any intracranial pathology. IIH mainly affects women with obesity between the ages of 15 and 45. Two possible mechanisms that could explain the increased CSF pressure in IIH are excessive CSF production by the choroid plexus (CP) epithelium or impaired CSF drainage from the brain. However, the molecular mechanisms controlling these mechanisms in IIH remain to be determined. METHODS: In vivo ventriculo-cisternal perfusion (VCP) and variable rate infusion (VRI) techniques were used to assess changes in rates of CSF secretion and resistance to CSF drainage in female and male Wistar rats fed either a control (C) or high-fat (HF) diet (under anaesthesia with 20 µl/100 g medetomidine, 50 µl/100 g ketamine i.p). In addition, CSF secretion and drainage were assessed in female rats following treatment with inflammatory mediators known to be elevated in the CSF of IIH patients: C-C motif chemokine ligand 2 (CCL2), interleukin (IL)-17 (IL-17), IL-6, IL-1ß, tumour necrosis factor-α (TNF-α), as well as glucocorticoid hydrocortisone (HC). RESULTS: Female rats fed the HF diet had greater CSF secretion compared to those on control diet (3.18 ± 0.12 µl/min HF, 1.49 ± 0.15 µl/min control). Increased CSF secretion was seen in both groups following HC treatment (by 132% in controls and 114% in HF) but only in control rats following TNF-α treatment (137% increase). The resistance to CSF drainage was not different between control and HF fed female rats (6.13 ± 0.44 mmH2O min/µl controls, and 7.09 ± 0.26 mmH2O min/µl HF). and when treated with CCL2, both groups displayed an increase in resistance to CSF drainage of 141% (controls) and 139% (HF) indicating lower levels of CSF drainage. CONCLUSIONS: Weight loss and therapies targeting HC, TNF-α and CCL2, whether separately or in combination, may be beneficial to modulate rates of CSF secretion and/or resistance to CSF drainage pathways, both factors likely contributing to the raised intracranial pressure (ICP) observed in female IIH patients with obesity.


Assuntos
Vazamento de Líquido Cefalorraquidiano/tratamento farmacológico , Líquido Cefalorraquidiano/efeitos dos fármacos , Citocinas/farmacologia , Dieta , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Citocinas/metabolismo , Feminino , Hidrodinâmica , Hipertensão Intracraniana/tratamento farmacológico , Pressão Intracraniana/efeitos dos fármacos , Masculino , Obesidade/complicações , Ratos Wistar
2.
J Tissue Eng ; 8: 2041731417697920, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28507726

RESUMO

Neurodegenerative conditions remain difficult to treat, with the continuing failure to see therapeutic research successfully advance to clinical trials. One of the obstacles that must be overcome is to develop enhanced models of disease. Tissue engineering techniques enable us to create organised artificial central nervous system tissue that has the potential to improve the drug development process. This study presents a replicable model of neurodegenerative pathology through the use of engineered neural tissue co-cultures that can incorporate cells from various sources and allow degeneration and protection of neurons to be observed easily and measured, following exposure to neurotoxic compounds - okadaic acid and 1-methyl-4-phenylpyridinium. Furthermore, the technology has been miniaturised through development of a mould with 6 mm length that recreates the advantageous features of engineered neural tissue co-cultures at a scale suitable for commercial research and development. Integration of human-derived induced pluripotent stem cells aids more accurate modelling of human diseases, creating new possibilities for engineered neural tissue co-cultures and their use in drug screening.

3.
J Biomater Appl ; 30(5): 599-607, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26245460

RESUMO

Engineered anisotropic tissue constructs containing aligned cell and extracellular matrix structures are useful as in vitro models and for regenerative medicine. They are of particular interest for nervous system modelling and regeneration, where tracts of aligned neurons and glia are required. The self-alignment of cells and matrix due to tension within tethered collagen gels is a useful tool for generating anisotropic tissues, but requires an optimal balance between cell density, matrix concentration and time to be achieved for each specific cell type. The aim of this study was to develop an assay system based on contraction of free-floating cellular gels in 96-well plates that could be used to investigate cell-matrix interactions and to establish optimal parameters for subsequent self-alignment of cells in tethered gels. Using C6 glioma cells, the relationship between contraction and alignment was established, with 60-80% contraction in the 96-well plate assay corresponding to alignment throughout tethered gels made using the same parameters. The assay system was used to investigate the effect of C6 cell density, collagen concentration and time. It was also used to show that blocking α1 integrin reduced the contraction and self-alignment of these cells, whereas blocking α2 integrin had little effect. The approach was validated by using primary astrocytes in the assay system under culture conditions that modified their ability to contract collagen gels. This detailed investigation describes a robust assay for optimising cellular self-alignment and provides a useful reference framework for future development of self-aligned artificial tissue.


Assuntos
Astrócitos/citologia , Colágeno/química , Hidrogéis/química , Neurônios/citologia , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Animais , Linhagem Celular Tumoral , Células Cultivadas , Ratos
4.
Regen Med ; 8(6): 739-46, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24147529

RESUMO

AIM: This study aimed to develop a 3D culture model to test the extent to which transplanted stem cells modulate astrocyte reactivity, where exacerbated glial cell activation could be detrimental to CNS repair success. MATERIALS & METHODS: The reactivity of rat astrocytes to bone marrow mesenchymal stem cells, neural crest stem cells (NCSCs) and differentiated adipose-derived stem cells was assessed after 5 days. Schwann cells were used as a positive control. RESULTS: NCSCs and differentiated Schwann cell-like adipose-derived stem cells did not increase astrocyte reactivity. Highly reactive responses to bone marrow mesenchymal stem cells and Schwann cells were equivalent. CONCLUSION: This approach can screen therapeutic cells prior to in vivo testing, allowing cells likely to trigger a substantial astrocyte response to be identified at an early stage. NCSCs and differentiated Schwann cell-like adipose-derived stem cells may be useful in treating CNS damage without increasing astrogliosis.


Assuntos
Astrócitos/citologia , Técnicas de Cultura de Células/métodos , Sistema Nervoso Central/lesões , Sistema Nervoso Central/patologia , Modelos Biológicos , Transplante de Células-Tronco , Células-Tronco/citologia , Animais , Técnicas de Cocultura , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Ratos , Ratos Endogâmicos F344 , Ratos Sprague-Dawley
5.
Brain Res ; 1292: 14-24, 2009 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-19631619

RESUMO

P-glycoprotein (P-gp) expression at the blood-brain barrier prevents unwanted blood-borne toxins and signalling molecules from entering the brain. Primary and immortalised human brain endothelial cells (BECs) represent two suitable options for studying P-gp function in vitro. The limited supply of primary human BECs and their instability over passage number make this choice unattractive for medium/high throughput studies. The aim of this study was to further characterise the expression of P-gp by an immortalised human BEC line, hCMEC/D3, in order to evaluate their use as an in vitro human blood-brain barrier model. P-gp expression was stable over a high passage number (up to passage 38) and was polarised on the apical plasma membrane, consistent with human BECs in vivo. In addition, hCMEC/D3 cell P-gp expression was comparable, albeit slightly lower to that observed in primary isolated human BECs although P-gp function was similar in both cell lines. The P-gp inhibitors tariquidar and vinblastine prevented the efflux of rhodamine 123 (rh123) from hCMEC/D3 cells, indicative of functional P-gp expression. hCMEC/D3 cells also displayed polarised P-gp transport, since both tariquidar and vinblasine selectively increased the apical-to-basolateral permeability of hCMEC/D3 cells to rh123. The results presented here demonstrate that hCMEC/D3 cells are a suitable model to investigate substrate specificity of P-gp in BECs of human origin.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Encéfalo/fisiologia , Permeabilidade da Membrana Celular/fisiologia , Células Endoteliais/fisiologia , Corantes Fluorescentes/farmacocinética , Rodamina 123/farmacocinética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Transporte Biológico/efeitos dos fármacos , Barreira Hematoencefálica/fisiologia , Encéfalo/efeitos dos fármacos , Permeabilidade Capilar , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Células Cultivadas , Fármacos do Sistema Nervoso Central/farmacologia , Células Endoteliais/efeitos dos fármacos , Humanos , Modelos Biológicos , Quinolinas/farmacologia , Vimblastina/farmacologia
6.
J Cereb Blood Flow Metab ; 29(6): 1079-83, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19367293

RESUMO

The clearance of amyloid beta (Abeta) from the brain represents a novel therapeutic target for Alzheimer's disease. Conflicting data exist regarding the contribution of adenosine triphosphate-binding cassette transporters to the clearance of Abeta through the blood-brain barrier. Therefore, we investigated whether Abeta could be a substrate for P-glycoprotein (P-gp) and/or for breast cancer resistance protein (BCRP) using a human brain endothelial cell line, hCMEC/D3. Inhibition of P-gp and BCRP increased apical-to-basolateral, but not basolateral-to-apical, permeability of hCMEC/D3 cells to (125)I Abeta 1-40. Our in vitro data suggest that P-gp and BCRP might act to prevent the blood-borne Abeta 1-40 from entering the brain.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Peptídeos beta-Amiloides/metabolismo , Barreira Hematoencefálica/metabolismo , Proteínas de Neoplasias/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Linhagem Celular , Endotélio/metabolismo , Humanos , Fragmentos de Peptídeos/metabolismo
7.
J Neuroimmunol ; 199(1-2): 35-45, 2008 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-18538864

RESUMO

The expression of chemokine receptors and chemokine production by adult human non-transformed astrocytes, grade III astrocytoma and grade IV glioblastoma tumour cell lines were determined. Here, we show an increased expression of CXCR3 and CXCR4, and a decreased expression of CXCR1 and CCR4 by glioma cells compared to adult human astrocytes. Glioma cells showed increased production of CXCL10, whereas production of other chemokines was decreased (CXCL8, CCL2, CCL5, and CCL22). CXCL10 induced an ERK1/2-dependent increase in [(3)H] thymidine uptake. These results suggest that expression of chemokine receptor/ligand pairs such as CXCR3/CXCL10 have an important role in the proliferation of glioma cells.


Assuntos
Proliferação de Células , Quimiocina CXCL10/biossíntese , Quimiocinas/biossíntese , Glioma/metabolismo , Receptores de Quimiocinas/biossíntese , Astrócitos/metabolismo , Western Blotting , Linhagem Celular Tumoral , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Citometria de Fluxo , Expressão Gênica , Humanos , RNA Mensageiro , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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