Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 99
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Neurosci ; 41(13): 3025-3038, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33597269

RESUMO

Alzheimer's disease is a devastating neurodegenerative disease with a dramatically increasing prevalence and no disease-modifying treatment. Inflammatory lifestyle factors increase the risk of developing Alzheimer's disease. Zinc deficiency is the most prevalent malnutrition in the world and may be a risk factor for Alzheimer's disease potentially through enhanced inflammation, although evidence for this is limited. Here we provide epidemiological evidence suggesting that zinc supplementation was associated with reduced risk and slower cognitive decline, in people with Alzheimer's disease and mild cognitive impairment. Using the APP/PS1 mouse model of Alzheimer's disease fed a control (35 mg/kg zinc) or diet deficient in zinc (3 mg/kg zinc), we determined that zinc deficiency accelerated Alzheimer's-like memory deficits without modifying amyloid ß plaque burden in the brains of male mice. The NLRP3-inflammasome complex is one of the most important regulators of inflammation, and we show here that zinc deficiency in immune cells, including microglia, potentiated NLRP3 responses to inflammatory stimuli in vitro, including amyloid oligomers, while zinc supplementation inhibited NLRP3 activation. APP/PS1 mice deficient in NLRP3 were protected against the accelerated cognitive decline with zinc deficiency. Collectively, this research suggests that zinc status is linked to inflammatory reactivity and may be modified in people to reduce the risk and slow the progression of Alzheimer's disease.SIGNIFICANCE STATEMENT Alzheimer's disease is a common condition mostly affecting the elderly. Zinc deficiency is also a global problem, especially in the elderly and also in people with Alzheimer's disease. Zinc deficiency contributes to many clinical disorders, including immune dysfunction. Inflammation is known to contribute to the risk and progression of Alzheimer's disease; thus, we hypothesized that zinc status would affect Alzheimer's disease progression. Here we show that zinc supplementation reduced the prevalence and symptomatic decline in people with Alzheimer's disease. In an animal model of Alzheimer's disease, zinc deficiency worsened cognitive decline because of an enhancement in NLRP3-driven inflammation. Overall, our data suggest that zinc status affects Alzheimer's disease progression, and that zinc supplementation could slow the rate of cognitive decline.


Assuntos
Doença de Alzheimer/sangue , Disfunção Cognitiva/sangue , Progressão da Doença , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Zinco/sangue , Adulto , Idoso , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/dietoterapia , Animais , Células Cultivadas , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/dietoterapia , Suplementos Nutricionais , Feminino , Seguimentos , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Zinco/administração & dosagem , Zinco/deficiência
2.
Glia ; 70(6): 1068-1083, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35150591

RESUMO

Microglia, resident brain immune cells, are critical in orchestrating responses to central nervous system (CNS) injury. Many microglial functions, such as phagocytosis, motility and chemotaxis, are suggested to rely on chloride channels, including the volume-regulated anion channel (VRAC), but studies to date have relied on the use of pharmacological tools with limited specificity. VRAC has also been proposed as a drug target for acute CNS injury, and its role in microglial function is of considerable interest for developing CNS therapeutics. This study aimed to definitively confirm the contribution of VRAC in microglia function by using conditional LRRC8A-knockout mice, which lacked the essential VRAC subunit LRRC8A in microglia. We demonstrated that while VRAC contributed to cell volume regulation, it had no effect on phagocytic activity, cell migration or P2YR12-dependent chemotaxis. Moreover, loss of microglial VRAC did not affect microglial morphology or the extent of ischemic damage following stroke. We conclude that VRAC does not critically regulate microglial responses to brain injury and could be targetable in other CNS cell types (e.g., astrocytes) without impeding microglial function. Our results also demonstrate a role for VRAC in cell volume regulation but show that VRAC is not involved in several major cellular functions that it was previously thought to regulate, and point to other, alternative mechanisms of chloride transport in innate immunity.


Assuntos
Microglia , Acidente Vascular Cerebral , Animais , Tamanho Celular , Transporte de Íons , Proteínas de Membrana/metabolismo , Camundongos , Microglia/metabolismo
3.
Glia ; 70(7): 1301-1316, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35353387

RESUMO

The NLRP3 (NLR family, pyrin domain containing 3) inflammasome is a multi-protein complex responsible for the activation of caspase-1 and the subsequent cleavage and activation of the potent proinflammatory cytokines IL-1ß and IL-18, and pyroptotic cell death. NLRP3 is implicated as a driver of inflammation in a range of disorders including neurodegenerative diseases, type 2 diabetes, and atherosclerosis. A commonly reported mechanism contributing to NLRP3 inflammasome activation is potassium ion (K+ ) efflux across the plasma membrane. Identification of K+ channels involved in NLRP3 activation remains incomplete. Here, we investigated the role of the K+ channel THIK-1 in NLRP3 activation. Both pharmacological inhibitors and cells from THIK-1 knockout (KO) mice were used to assess THIK-1 contribution to macrophage NLRP3 activation in vitro. Pharmacological inhibition of THIK-1 inhibited caspase-1 activation and IL-1ß release from mouse bone-marrow-derived macrophages (BMDMs), mixed glia, and microglia in response to NLRP3 agonists. Similarly, BMDMs and microglia from THIK-1 KO mice had reduced NLRP3-dependent IL-1ß release in response to P2X7 receptor activation with ATP. Overall, these data suggest that THIK-1 is a regulator of NLRP3 inflammasome activation in response to ATP and identify THIK-1 as a potential therapeutic target for inflammatory disease.


Assuntos
Diabetes Mellitus Tipo 2 , Inflamassomos , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Caspase 1/metabolismo , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Potássio/metabolismo , Canais de Potássio
4.
Immunology ; 162(1): 84-91, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32954500

RESUMO

Excessive and dysregulated inflammation is known to contribute to disease progression. HSP90 is an intracellular chaperone known to regulate inflammatory processes including the NLRP3 inflammasome and secretion of the pro-inflammatory cytokine interleukin(IL)-1ß. Here, primarily using an in vitro inflammasome ASC speck assay, and an in vivo model of murine peritonitis, we tested the utility of HSP90 inhibitors as anti-inflammatory molecules. We report that the HSP90 inhibitor EC144 effectively inhibited inflammatory processes including priming and activation of NLRP3 in vitro and in vivo. A specific inhibitor of the ß HSP90 isoform was ineffective suggesting the importance of the α isoform in inflammatory signalling. EC144 inhibited IL-1ß and IL-6 in vivo when administered orally, and was brain-penetrant. These data suggest that HSP90 inhibitors may be useful for targeting inflammation in diverse diseases that are worsened by the presence of inflammation.


Assuntos
Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Citocinas/metabolismo , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Peritonite/metabolismo , Isoformas de Proteínas/metabolismo , Transdução de Sinais/fisiologia
5.
Proc Natl Acad Sci U S A ; 115(40): E9371-E9380, 2018 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-30232264

RESUMO

The NLRP3 inflammasome is an important regulator of inflammation and immunity. It is a multimolecular platform formed within cells that facilitates the activation of proinflammatory caspases to drive secretion of cytokines such as interleukin-1ß (IL-1ß). Knowledge of the mechanisms regulating formation of the NLRP3 inflammasome is incomplete. Here we report Cl- channel-dependent formation of dynamic ASC oligomers and inflammasome specks that remain inactive in the absence of K+ efflux. Formed after Cl- efflux exclusively, ASC specks are NLRP3 dependent, reversible, and inactive, although they further prime inflammatory responses, accelerating and enhancing release of IL-1ß in response to a K+ efflux-inducing stimulus. NEK7 is a specific K+ sensor and does not associate with NLRP3 under conditions stimulating exclusively Cl- efflux, but does after K+ efflux, activating the complex driving inflammation. Our investigation delivers mechanistic understanding into inflammasome activation and the regulation of inflammatory responses.


Assuntos
Proteínas Adaptadoras de Sinalização CARD/metabolismo , Cloretos/metabolismo , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Multimerização Proteica , Animais , Proteínas Adaptadoras de Sinalização CARD/genética , Feminino , Inflamassomos/genética , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Transporte de Íons/genética , Masculino , Camundongos , Camundongos Knockout , Quinases Relacionadas a NIMA/genética , Quinases Relacionadas a NIMA/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Potássio/metabolismo
6.
Health Info Libr J ; 38(2): 97-112, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33196136

RESUMO

BACKGROUND: Timely information provided by clinical librarians can contribute to outcomes such as improved patient care and time savings for hospital staff. What is unknown is the return on investment (ROI) of a clinical librarian on a critical care unit. OBJECTIVE: The aim of this study was to assess the ROI, from the employer perspective, of placing a clinical librarian in a critical care unit in a large UK acute hospital. METHODS: Using a mixed methods approach, ROI was estimated by comparing the total costs with the total monetised benefits of implementing the clinical librarian intervention. Total costs included salary and equipment costs. Total monetised benefits included time saving for hospital staff, support for professional development and improved patient care. RESULTS: When total monetised benefits were compared with total costs, the 15-month clinical librarian intervention generated a positive ROI of £1.18-£3.03 for every £1 invested. DISCUSSION: Using outcome measures derived from previous research, this novel study generated promising results indicative for commissioners seeking to improve patient care and deliver value for money. To improve generalisability, multisite studies using standardised ROI tools are recommended. CONCLUSION: Employing a clinical librarian in a critical care unit can generate a positive ROI.


Assuntos
Biblioteconomia/métodos , Serviços de Biblioteca/normas , Papel Profissional , Análise Custo-Benefício/métodos , Humanos , Unidades de Terapia Intensiva/economia , Unidades de Terapia Intensiva/organização & administração , Biblioteconomia/economia , Biblioteconomia/tendências , Serviços de Biblioteca/tendências
7.
Molecules ; 24(6)2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30884752

RESUMO

Twelve propolis samples from different parts of Libya were investigated for their phytochemical constituents. Ethanol extracts of the samples and some purified compounds were tested against Trypanosoma brucei, Plasmodium falciparum and against two helminth species, Trichinella spiralis and Caenorhabditis elegans, showing various degrees of activity. Fourteen compounds were isolated from the propolis samples, including a novel compound Taxifolin-3-acetyl-4'-methyl ether (4), a flavanonol derivative. The crude extracts showed moderate activity against T. spiralis and C. elegans, while the purified compounds had low activity against P. falciparum. Anti-trypanosomal activity (EC50 = 0.7 µg/mL) was exhibited by a fraction containing a cardol identified as bilobol (10) and this fraction had no effect on Human Foreskin Fibroblasts (HFF), even at 2.0 mg/mL, thus demonstrating excellent selectivity. A metabolomics study was used to explore the mechanism of action of the fraction and it revealed significant disturbances in trypanosomal phospholipid metabolism, especially the formation of choline phospholipids. We conclude that a potent and highly selective new trypanocide may be present in the fraction.


Assuntos
Antiprotozoários/química , Proliferação de Células/efeitos dos fármacos , Própole/química , Trypanosoma brucei brucei/efeitos dos fármacos , Animais , Antiprotozoários/farmacologia , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/patogenicidade , Linhagem Celular , Fibroblastos/efeitos dos fármacos , Humanos , Líbia , Metabolômica , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/patogenicidade , Polifenóis/química , Polifenóis/farmacologia , Própole/farmacologia , Trichinella spiralis/efeitos dos fármacos , Trichinella spiralis/patogenicidade , Trypanosoma brucei brucei/patogenicidade
8.
Clin Sci (Lond) ; 132(8): 851-868, 2018 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-29712883

RESUMO

Cerebral small vessel disease (SVD) is a major contributor to stroke, cognitive impairment and dementia with limited therapeutic interventions. There is a critical need to provide mechanistic insight and improve translation between pre-clinical research and the clinic. A 2-day workshop was held which brought together experts from several disciplines in cerebrovascular disease, dementia and cardiovascular biology, to highlight current advances in these fields, explore synergies and scope for development. These proceedings provide a summary of key talks at the workshop with a particular focus on animal models of cerebral vascular disease and dementia, mechanisms and approaches to improve translation. The outcomes of discussion groups on related themes to identify the gaps in knowledge and requirements to advance knowledge are summarized.


Assuntos
Doenças de Pequenos Vasos Cerebrais/etiologia , Pesquisa Translacional Biomédica , Animais , Humanos
9.
J Neuroinflammation ; 12: 140, 2015 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-26239227

RESUMO

BACKGROUND: Obesity increases the risk for ischaemic stroke and is associated with worse outcome clinically and experimentally. Most experimental studies have used genetic models of obesity. Here, a more clinically relevant model, diet-induced obesity, was used to study the impact of obesity over time on the outcome and inflammatory response after stroke. METHODS: Male C57BL/6 mice were maintained on a high-fat (60% fat) or control (12% fat) diet for 2, 3, 4 and 6 months when experimental stroke was induced by transient occlusion of the middle cerebral artery (MCAo) for either 20 (6-month diet) or 30 min (2-, 3-, 4- and 6-month diet). Ischaemic damage, blood-brain barrier (BBB) integrity, neutrophil number and chemokine expression in the brain were assessed at 24 h. Plasma chemokine levels (at 4 and 24 h) and neutrophil number in the liver (at 24 h) were measured. Physiological parameters (body weight and blood glucose) were measured in naïve control- and high-fat-fed mice at all time points and blood pressure at 3 and 6 months. Blood cell counts were also assessed in naïve 6-month control- and high-fat-fed mice. RESULTS: Mice fed a high-fat diet for 6 months had greater body weight, blood glucose and white and red blood cell count but no change in systolic blood pressure. After 4 and 6 months of high-fat feeding, and in the latter group with a 30-min (but not 20-min) occlusion of the MCA, obese mice had greater ischaemic brain damage. An increase in blood-brain barrier permeability, chemokine expression (CXCL-1 and CCL3), neutrophil number and microglia/macrophage cells was observed in the brains of 6-month high-fat-fed mice after 30-min MCAo. In response to stroke, chemokine (CXCL-1) expression in the plasma and liver was significantly different in obese mice (6-month high-fat fed), and a greater number of neutrophils were detected in the liver of control but not obese mice. CONCLUSIONS: The detrimental effects of diet-induced obesity on stroke were therefore dependent on the severity of obesity and length of ischaemic challenge. The altered inflammatory response in obese mice may play a key role in its negative impact on stroke.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Inflamação/fisiopatologia , Obesidade/etiologia , Obesidade/fisiopatologia , Índice de Gravidade de Doença , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Animais , Contagem de Células Sanguíneas , Glicemia/metabolismo , Pressão Sanguínea/fisiologia , Peso Corporal/fisiologia , Quimiocinas/metabolismo , Modelos Animais de Doenças , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/patologia , Obesidade/metabolismo , Prognóstico , Distribuição Aleatória , Acidente Vascular Cerebral/metabolismo , Fatores de Tempo
10.
bioRxiv ; 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38464243

RESUMO

Hyperinflammatory disease is associated with an aberrant immune response resulting in cytokine storm. One such instance of hyperinflammatory disease is known as macrophage activation syndrome (MAS). The pathology of MAS can be characterised by significantly elevated serum levels of interleukin (IL)-18 and interferon (IFN)-γ. Given the role for IL-18 in MAS, we sought to establish the role of inflammasomes in the disease process. Using a murine model of CpG-DNA induced MAS, we discovered that the expression of the NLRP3 inflammasome was increased and correlated with IL-18 production. Inhibition of the NLRP3 inflammasome, or downstream caspase-1, prevented MAS-mediated upregulation of plasma IL-18 but interestingly did not alleviate key features of hyperinflammatory disease including hyperferritinaemia and splenomegaly. Furthermore IL-1 receptor blockade with IL-1Ra did not prevent the development of CpG-induced MAS, despite being clinically effective in the treatment of MAS. These data demonstrate that in the development of MAS, the NLRP3 inflammasome was essential for the elevation in plasma IL-18, a key cytokine in clinical cases of MAS, but was not a driving factor in the pathogenesis of CpG-induced MAS.

11.
Dis Model Mech ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38775430

RESUMO

Hyperinflammatory disease is associated with an aberrant immune response resulting in cytokine storm. One such instance of hyperinflammatory disease is known as macrophage activation syndrome (MAS). The pathology of MAS can be characterised by significantly elevated serum levels of interleukin (IL)-18 and interferon (IFN)-γ. Given the role for IL-18 in MAS, we sought to establish the role of inflammasomes in the disease process. Using a murine model of CpG-DNA induced MAS, we discovered that the expression of the NLRP3 inflammasome was increased and correlated with IL-18 production. Inhibition of the NLRP3 inflammasome, or downstream caspase-1, prevented MAS-mediated upregulation of plasma IL-18 but interestingly did not alleviate key features of hyperinflammatory disease including hyperferritinaemia and splenomegaly. Furthermore IL-1 receptor blockade with IL-1Ra did not prevent the development of CpG-induced MAS, despite being clinically effective in the treatment of MAS. These data demonstrate that in the development of MAS, the NLRP3 inflammasome was essential for the elevation in plasma IL-18, a key cytokine in clinical cases of MAS, but was not a driving factor in the pathogenesis of CpG-induced MAS.

12.
iScience ; 27(2): 108968, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38327788

RESUMO

Excessive or aberrant NLRP3 inflammasome activation has been implicated in the progression and initiation of many inflammatory conditions; however, currently no NLRP3 inflammasome inhibitors have been approved for therapeutic use in the clinic. Here we have identified that the natural product brazilin effectively inhibits both priming and activation of the NLRP3 inflammasome in cultured murine macrophages, a human iPSC microglial cell line and in a mouse model of acute peritoneal inflammation. Through computational modeling, we predict that brazilin can adopt a favorable binding pose within a site of the NLRP3 protein which is essential for its conformational activation. Our results not only encourage further evaluation of brazilin as a therapeutic agent for NLRP3-related inflammatory diseases, but also introduce this small-molecule as a promising scaffold structure for the development of derivative NLRP3 inhibitor compounds.

13.
Neurophysiol Clin ; 54(5): 102997, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38991470

RESUMO

OBJECTIVES: Aberrant movement-related cortical activity has been linked to impaired motor function in Parkinson's disease (PD). Dopaminergic drug treatment can restore these, but dosages and long-term treatment are limited by adverse side-effects. Effective non-pharmacological treatments could help reduce reliance on drugs. This experiment reports the first study of home-based electroencephalographic (EEG) neurofeedback training as a non-pharmacological candidate treatment for PD. Our primary aim was to test the feasibility of our EEG neurofeedback intervention in a home setting. METHODS: Sixteen people with PD received six home visits comprising symptomology self-reports, a standardised motor assessment, and a precision handgrip force production task while EEG was recorded (visits 1, 2 and 6); and 3 × 1-hr EEG neurofeedback training sessions to supress the EEG mu rhythm before initiating handgrip movements (visits 3 to 5). RESULTS: Participants successfully learned to self-regulate mu activity, and this appeared to expedite the initiation of precision movements (i.e., time to reach target handgrip force off-medication pre-intervention = 628 ms, off-medication post-intervention = 564 ms). There was no evidence of wider symptomology reduction (e.g., Movement Disorder Society Unified Parkinson's Disease Rating Scale Part III Motor Examination, off-medication pre-intervention = 29.00, off-medication post intervention = 30.07). Interviews indicated that the intervention was well-received. CONCLUSION: Based on the significant effect of neurofeedback on movement-related cortical activity, positive qualitative reports from participants, and a suggestive benefit to movement initiation, we conclude that home-based neurofeedback for people with PD is a feasible and promising non-pharmacological treatment that warrants further research.

14.
Transl Stroke Res ; 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37853252

RESUMO

Intracerebral haemorrhage (ICH) is the deadliest form of stroke, but current treatment options are limited, meaning ICH survivors are often left with life-changing disabilities. The significant unmet clinical need and socioeconomic burden of ICH mean novel regenerative medicine approaches are gaining interest. To facilitate the regeneration of the ICH lesion, injectable biomimetic hydrogels are proposed as both scaffolds for endogenous repair and delivery platforms for pro-regenerative therapies. In this paper, the objective was to explore whether injection of a novel self-assembling peptide hydrogel (SAPH) Alpha2 was feasible, safe and could stimulate brain tissue regeneration, in a collagenase-induced ICH model in rats. Alpha2 was administered intracerebrally at 7 days post ICH and functional outcome measures, histological markers of damage and repair and RNA-sequencing were investigated for up to 8 weeks. The hydrogel Alpha2 was safe, well-tolerated and was retained in the lesion for several weeks, where it allowed infiltration of host cells. The hydrogel had a largely neutral effect on functional outcomes and expression of angiogenic and neurogenic markers but led to increased numbers of proliferating cells. RNAseq and pathway analysis showed that ICH altered genes related to inflammatory and phagocytic pathways, and these changes were also observed after administration of hydrogel. Overall, the results show that the novel hydrogel was safe when injected intracerebrally and had no negative effects on functional outcomes but increased cell proliferation. To elicit a regenerative effect, future studies could use a functionalised hydrogel or combine it with an adjunct therapy.

15.
Fluids Barriers CNS ; 20(1): 25, 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-37013549

RESUMO

Blood-brain barrier (BBB) dysfunction occurs in many brain diseases, and there is increasing evidence to suggest that it is an early process in dementia which may be exacerbated by peripheral infection. Filter-exchange imaging (FEXI) is an MRI technique for measuring trans-membrane water exchange. FEXI data is typically analysed using the apparent exchange rate (AXR) model, yielding estimates of the AXR. Crusher gradients are commonly used to remove unwanted coherence pathways arising from longitudinal storage pulses during the mixing period. We first demonstrate that when using thin slices, as is needed for imaging the rodent brain, crusher gradients result in underestimation of the AXR. To address this, we propose an extended crusher-compensated exchange rate (CCXR) model to account for diffusion-weighting introduced by the crusher gradients, which is able to recover ground truth values of BBB water exchange (kin) in simulated data. When applied to the rat brain, kin estimates obtained using the CCXR model were 3.10 s-1 and 3.49 s-1 compared to AXR estimates of 1.24 s-1 and 0.49 s-1 for slice thicknesses of 4.0 mm and 2.5 mm respectively. We then validated our approach using a clinically relevant Streptococcus pneumoniae lung infection. We observed a significant 70 ± 10% increase in BBB water exchange in rats during active infection (kin = 3.78 ± 0.42 s-1) compared to before infection (kin = 2.72 ± 0.30 s-1; p = 0.02). The BBB water exchange rate during infection was associated with higher levels of plasma von Willebrand factor (VWF), a marker of acute vascular inflammation. We also observed 42% higher expression of perivascular aquaporin-4 (AQP4) in infected animals compared to non-infected controls, while levels of tight junction proteins remain consistent between groups. In summary, we propose a modelling approach for FEXI data which removes the bias in estimated water-exchange rates associated with the use of crusher gradients. Using this approach, we demonstrate the impact of peripheral infection on BBB water exchange, which appears to be mediated by endothelial dysfunction and associated with an increase in perivascular AQP4.


Assuntos
Barreira Hematoencefálica , Água , Ratos , Animais , Barreira Hematoencefálica/metabolismo , Água/metabolismo , Encéfalo/metabolismo , Imageamento por Ressonância Magnética/métodos , Aquaporina 4/metabolismo , Pulmão/metabolismo
16.
Neuropharmacology ; 224: 109330, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36375694

RESUMO

Neuroinflammation, specifically the NLRP3 inflammasome cascade, is a common underlying pathological feature of many neurodegenerative diseases. Evidence suggests that NLRP3 activation involves changes in intracellular K+. Nuclear Enriched Transcript Sort Sequencing (NETSseq), which allows for deep sequencing of purified cell types from human post-mortem brain tissue, demonstrated a highly specific expression of the tandem pore domain halothane-inhibited K+ channel 1 (THIK-1) in microglia compared to other glial and neuronal cell types in the human brain. NETSseq also showed a significant increase of THIK-1 in microglia isolated from cortical regions of brains with Alzheimer's disease (AD) relative to control donors. Herein, we report the discovery and pharmacological characterisation of C101248, the first selective small-molecule inhibitor of THIK-1. C101248 showed a concentration-dependent inhibition of both mouse and human THIK-1 (IC50: ∼50 nM) and was inactive against K2P family members TREK-1 and TWIK-2, and Kv2.1. Whole-cell patch-clamp recordings of microglia from mouse hippocampal slices showed that C101248 potently blocked both tonic and ATP-evoked THIK-1 K+ currents. Notably, C101248 had no effect on other constitutively active resting conductance in slices from THIK-1-depleted mice. In isolated microglia, C101248 prevented NLRP3-dependent release of IL-1ß, an effect not seen in THIK-1-depleted microglia. In conclusion, we demonstrated that inhibiting THIK-1 (a microglia specific gene that is upregulated in brains from donors with AD) using a novel selective modulator attenuates the NLRP3-dependent release of IL-1ß from microglia, which suggests that this channel may be a potential therapeutic target for the modulation of neuroinflammation in AD.


Assuntos
Doença de Alzheimer , Inflamassomos , Canais de Potássio de Domínios Poros em Tandem , Animais , Humanos , Camundongos , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Inflamassomos/metabolismo , Microglia , Doenças Neuroinflamatórias , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Canais de Potássio de Domínios Poros em Tandem/antagonistas & inibidores
17.
Cereb Circ Cogn Behav ; 5: 100189, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37941765

RESUMO

Although dementia research has been dominated by Alzheimer's disease (AD), most dementia in older people is now recognised to be due to mixed pathologies, usually combining vascular and AD brain pathology. Vascular cognitive impairment (VCI), which encompasses vascular dementia (VaD) is the second most common type of dementia. Models of VCI have been delayed by limited understanding of the underlying aetiology and pathogenesis. This review by a multidisciplinary, diverse (in terms of sex, geography and career stage), cross-institute team provides a perspective on limitations to current VCI models and recommendations for improving translation and reproducibility. We discuss reproducibility, clinical features of VCI and corresponding assessments in models, human pathology, bioinformatics approaches, and data sharing. We offer recommendations for future research, particularly focusing on small vessel disease as a main underpinning disorder.

18.
Front Neuroendocrinol ; 32(1): 1-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20558195

RESUMO

Galanin-like peptide (GALP) was discovered in 1999 in the porcine hypothalamus and was found to be a 60 amino acid neuropeptide. GALP shares sequence homology to galanin (1-13) in position 9-21 and can bind to, as well as activate, the three galanin receptor subtypes (GalR1-3). GALP-expressing cells are limited, and are mainly found in the arcuate nucleus of the hypothalamus (ARC) and the posterior pituitary. GALP-positive neurons in the ARC project to several brain regions where they appear to make contact with multiple neuromodulators. These neuromodulators are involved in the regulation of energy homeostasis and reproduction, anatomical evidence that suggests a role for GALP in these physiological functions. In support of this idea, GALP gene expression is regulated by several factors that reflect metabolic state including the metabolic hormones leptin and insulin, thyroid hormones, and blood glucose. Considerable evidence now exists to support the hypothesis that GALP has a role in the regulation of energy homeostasis and reproduction; and, that GALP's role may be independent of the known galanin receptors. In this review, we (1) provide an overview of the distribution of GALP, and discuss the potential relationship between GALP and other neuromodulators of energy homeostasis and reproduction, (2) discuss the metabolic factors that regulate GALP expression, (3) review the evidence for the role of GALP in energy homeostasis and reproduction, (4) discuss the potential downstream mediators and mechanisms underlying GALP's effects, and (5) discuss the possibility that GALP may mediate its effects via an as yet unidentified GALP-specific receptor.


Assuntos
Metabolismo Energético/genética , Peptídeo Semelhante a Galanina/fisiologia , Hipotálamo/metabolismo , Reprodução/genética , Animais , Regulação do Apetite/genética , Sequência de Bases , Galanina/genética , Galanina/metabolismo , Galanina/fisiologia , Peptídeo Semelhante a Galanina/genética , Peptídeo Semelhante a Galanina/metabolismo , Homeostase/genética , Humanos , Modelos Biológicos , Dados de Sequência Molecular , Filogenia , Reprodução/fisiologia , Homologia de Sequência
19.
Discov Immunol ; 1(1): kyac005, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-38566906

RESUMO

Inflammasomes and the interleukin (IL)-1 family of cytokines are key mediators of both inflammation and immunothrombosis. Inflammasomes are responsible for the release of the pro-inflammatory cytokines IL-1ß and IL-18, as well as releasing tissue factor (TF), a pivotal initiator of the extrinsic coagulation cascade. Uncontrolled production of inflammatory cytokines results in what is known as a "cytokine storm" leading to hyperinflammatory disease. Cytokine storms can complicate a variety of diseases and results in hypercytokinemia, coagulopathies, tissue damage, multiorgan failure, and death. Patients presenting with cytokine storm syndromes have a high mortality rate, driven in part by disseminated intravascular coagulation (DIC). While our knowledge on the factors propagating cytokine storms is increasing, how cytokine storm influences DIC remains unknown, and therefore treatments for diseases, where these aspects are a key feature are limited, with most targeting specific cytokines. Currently, no therapies target the immunothrombosis aspect of hyperinflammatory syndromes. Here we discuss how targeting the inflammasome and pyroptosis may be a novel therapeutic strategy for the treatment of hyperinflammation and its associated pathologies.

20.
Appl Health Econ Health Policy ; 19(5): 653-664, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34056701

RESUMO

Health economists are currently debating, with some suspicion, the relative merits of cost-benefit analysis (CBA), grounded in theoretical welfare economics, and the proliferation of social return on investment (SROI), a pragmatic approach of developing a triple-bottom line (social, environmental and financial), but not grounded in welfare theory. We argue, in rather existential terms, that there is a need to understand the role of heuristics, or prior beliefs, in current 'best practice' in CBA and SROI. A taxonomy of CBA and SROI is presented, which summarises the origins of the methods, reporting guidance, publication checklist of quality of reporting, who is wanting these analytical approaches, and policy decision rule present. We argue that a bottom-up SROI is best thought of as localised CBA, building stakeholder involvement right into the framing of SROI, perhaps addressing or mitigating the effects of prior heuristics in top-down CBA. Behavioural CBA and social CBA recognise that people are not rational and that sources of value other than willingness to pay may best reflect social values. Standardisation of SROI and comparison with CBA may illuminate the role of prior heuristics and seek to better reflect social value in weighing up the costs and benefits of public health interventions at both a local and societal level.


Assuntos
Heurística , Saúde Pública , Análise Custo-Benefício , Humanos , Valores Sociais , Seguridade Social
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA