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1.
Small ; 20(31): e2311670, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38461531

RESUMO

Early detection and treatment are crucial for Alzheimer's disease (AD) management. Current diagnostic and therapeutic methods focus on late-stage amyloid fibrils and plaques, overlooking toxic soluble amyloid ß oligomers (AßOs) accumulating early in AD. A multifunctional liposome-based platform is designed for early diagnosis and therapy of AD, leveraging a novel self-assembled cyclic d,l-α-peptide (CP-2) that selectively targets AßOs. Biocompatible CP-2 conjugated liposomes (CP-2-LPs) effectively disrupt Aß aggregation and mitigate Aß-mediated toxicity in human neuroblastoma cells. In transgenic Caenorhabditis elegans AD models, CP-2-LPs significantly outperformed free CP-2 by improving cognitive and behavioral functions, extending lifespan, and reducing toxic AßO levels. Intravenous injection of fluorescently labeled CP-2-LPs reveals effective blood-brain barrier penetration, with significantly higher brain fluorescence in transgenic mice than WT, enabling precise diagnosis. These findings underscore CP-2-LPs as a valuable tool for early detection and targeted therapy in AD.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Caenorhabditis elegans , Lipossomos , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Lipossomos/química , Animais , Humanos , Caenorhabditis elegans/metabolismo , Diagnóstico Precoce , Camundongos Transgênicos , Camundongos , Modelos Animais de Doenças , Linhagem Celular Tumoral , Barreira Hematoencefálica/metabolismo
2.
Neurol Sci ; 45(9): 4383-4390, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38523206

RESUMO

OBJECTIVES: Blood-brain barrier (BBB) disruption is an important pathological change after cerebral infarction that exacerbates brain injury. We aimed to investigate and compare the predictive utility of pre-treatment BBB permeability (BBBP) and BBBP within 1 h after endovascular treatment (EVT) for hemorrhagic transformation (HT) and 90-day prognosis. METHODS: Patients underwent preoperative computed tomography perfusion (CTP) and non-contrast CT (NCCT) within 1 h after EVT. Preoperative BBBP was determined by the relative permeability surface area product (rPS) in the hypoperfusion area. Postoperative BBBP was determined by the post-EVT Alberta Stroke Program Early CT Score (Post-ASPECTS), which is based on brain parenchymal hyperdensity on the postoperative NCCT. OUTCOMES: We included 100 patients. Univariate logistic regression analysis revealed correlations of preoperative rPS with HT, poor outcomes, and death. However, these correlations were not observed in multivariate logistic regression. A Post-ASPECTS ≤7 and could independently predict poor outcomes, while Post-ASPECTS ≤6 could independently predict death and HT. The baseline National Institutes of Health Stroke Scale (NIHSS) score could independently predict poor outcomes and death but not HT. A combined model using the baseline NIHSS and Post-ASPECTS scores had better predictive performance for poor outcomes and death than baseline NIHSS score alone; however, it was not superior to the predictive performance of the Post-ASPECTS score. CONCLUSION: The preoperative rPS cannot independently predict clinical outcomes in EVT-treated patients; contrastingly, the Post-ASPECTS score could independently predict poor outcomes, death, and HT. This parameter could inform prompt postoperative treatment decisions.


Assuntos
Barreira Hematoencefálica , Procedimentos Endovasculares , Humanos , Masculino , Feminino , Idoso , Barreira Hematoencefálica/diagnóstico por imagem , Pessoa de Meia-Idade , Prognóstico , Resultado do Tratamento , Tomografia Computadorizada por Raios X , Estudos Retrospectivos , Idoso de 80 Anos ou mais
3.
Biomed Chromatogr ; 38(7): e5867, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38558037

RESUMO

Fourteen donepezil-like acetylcholinesterase (AChE) inhibitors from our library were analyzed using reversed-phase thin-layer chromatography to assess their lipophilicity and blood-brain barrier permeability. Compounds possessed N-benzylpiperidine and N,N-diarylpiperazine moieties connected via a short carboxamide or amine linker. Retention parameters RM 0, b, and C0 were considered as the measures of lipophilicity. Besides, logD of the investigated compounds was determined chromatographically using standard compounds with known logPow and logD values at pH 11. Experimentally obtained lipophilicity parameters correlated well with in silico generated results, and the effect of the nature of the linker between two pharmacophores and substituents on the arylpiperazine part of the molecule was observed. As a result of drug-likeness analysis, both Lipinski's rule of five and Veber's rule parameters were determined, suggesting that examined compounds could be potential candidates for further drug development. Principal component analysis was performed to obtain an insight into a grouping of compounds based on calculated structural descriptors, experimentally obtained values of lipophilicity, and AChE inhibitory activity.


Assuntos
Inibidores da Colinesterase , Cromatografia de Fase Reversa , Donepezila , Interações Hidrofóbicas e Hidrofílicas , Piperidinas , Cromatografia em Camada Fina/métodos , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Cromatografia de Fase Reversa/métodos , Donepezila/química , Donepezila/farmacologia , Piperidinas/química , Indanos/química , Barreira Hematoencefálica/metabolismo , Análise de Componente Principal
4.
Int J Mol Sci ; 25(7)2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38612476

RESUMO

The review introduces the stages of formation and experimental confirmation of the hypothesis regarding the mutual potentiation of neuroprotective effects of hypoxia and hypercapnia during their combined influence (hypercapnic hypoxia). The main focus is on the mechanisms and signaling pathways involved in the formation of ischemic tolerance in the brain during intermittent hypercapnic hypoxia. Importantly, the combined effect of hypoxia and hypercapnia exerts a more pronounced neuroprotective effect compared to their separate application. Some signaling systems are associated with the predominance of the hypoxic stimulus (HIF-1α, A1 receptors), while others (NF-κB, antioxidant activity, inhibition of apoptosis, maintenance of selective blood-brain barrier permeability) are mainly modulated by hypercapnia. Most of the molecular and cellular mechanisms involved in the formation of brain tolerance to ischemia are due to the contribution of both excess carbon dioxide and oxygen deficiency (ATP-dependent potassium channels, chaperones, endoplasmic reticulum stress, mitochondrial metabolism reprogramming). Overall, experimental studies indicate the dominance of hypercapnia in the neuroprotective effect of its combined action with hypoxia. Recent clinical studies have demonstrated the effectiveness of hypercapnic-hypoxic training in the treatment of childhood cerebral palsy and diabetic polyneuropathy in children. Combining hypercapnic hypoxia with pharmacological modulators of neuro/cardio/cytoprotection signaling pathways is likely to be promising for translating experimental research into clinical medicine.


Assuntos
Neuroproteção , Fármacos Neuroprotetores , Criança , Humanos , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Hipercapnia , Dióxido de Carbono , Hipóxia
5.
Int J Mol Sci ; 25(2)2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38255872

RESUMO

Alzheimer's disease (AD) is a complex and multifactorial neurodegenerative disorder characterized by cognitive decline, memory loss, behavioral changes, and other neurological symptoms. Considering the urgent need for new AD therapeutics, in the present study we designed, synthesized, and evaluated multitarget compounds structurally inspired by sulfonylureas and pitolisant with the aim of obtaining multitarget ligands for AD treatment. Due to the diversity of chemical scaffolds, a novel strategy has been adopted by merging into one structure moieties displaying H3R antagonism and acetylcholinesterase inhibition. Eight compounds, selected by their binding activity on H3R, showed a moderate ability to inhibit acetylcholinesterase activity in vitro, and two of the compounds (derivatives 2 and 7) were also capable of increasing acetylcholine release in vitro. Among the tested compounds, derivative 2 was identified and selected for further in vivo studies. Compound 2 was able to reverse scopolamine-induced cognitive deficits with results comparable to those of galantamine, a drug used in clinics for treating AD. In addition to its efficacy, this compound showed moderate BBB permeation in vitro. Altogether, these results point out that the fragment-like character of compound 2 leads to an optimal starting point for a plausible medicinal chemistry approach for this novel strategy.


Assuntos
Doença de Alzheimer , Piperidinas , Humanos , Doença de Alzheimer/tratamento farmacológico , Acetilcolinesterase , Galantamina , Acetilcolina
6.
Bioorg Chem ; 139: 106719, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37473478

RESUMO

Caffeine is one of the privileged natural products that shows numerous effects on the central nervous system. Herein, thirty-one caffeine-based amide derivatives were synthesized and evaluated in vitro for their anticholinesterase activity. The introduction of the amide group to the caffeine core augmented its anticholinesterase activity from an IC50 value of 128 to 1.32 µM (derivative, 6i). The SAR study revealed that N7 substitution on caffeine core is favorable over N1, and the presence of amide 'carbonyl' as a part of the linker contributes to the biological activity. The caffeine core of 6i exhibits interactions with the peripheral anionic site, whereas the N-benzyl ring fits nicely inside the catalytic anionic site. Analog 6i inhibits AChE in a mixed-type mode (Ki 4.58 µM) and crosses the BBB in an in-vitro PAMPA assay. Compound 6i has a descent metabolic stability in MLM (>70% remaining after 30 min) and favorable oral pharmacokinetics in Swiss albino mice.


Assuntos
Doença de Alzheimer , Inibidores da Colinesterase , Camundongos , Animais , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/metabolismo , Cafeína/farmacologia , Acetilcolinesterase/metabolismo , Barreira Hematoencefálica , Amidas/farmacologia , Amidas/metabolismo , Simulação de Acoplamento Molecular , Doença de Alzheimer/metabolismo , Relação Estrutura-Atividade
7.
Biomed Chromatogr ; 37(6): e5631, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36987546

RESUMO

Eucalyptol, a natural epoxide monoterpene, was found in rat brain tissue after oral administration in our previous study, suggesting that the compound may possess the ability to pass the blood-brain barrier (BBB). However, a few studies have demonstrated that eucalyptol does penetrate the BBB. The aims of this study were to determine the opening effect of eucalyptol on the BBB in rats, to establish and validate a method for the determination of eucalyptol in brain tissue, and to reveal its brain pharmacokinetic characteristics. The opening effect of BBB was assessed by dye extravasation and ultrastructural alterations, and the quantitative method of eucalyptol in rat brain tissue was established and confirmed. For pharmacokinetic research, rat brain samples were taken at 0.05, 0.167, 0.5, 1, 2.5, 5, 10, and 15 h after administration. There was a significantly higher extravasation of Evans blue from the brain parenchyma of rats in the medium-dose eucalyptol group (P < 0.01), which was associated with the BBB's altered ultrastructure. It is suggested that eucalyptol increased the permeability of the BBB. After oral administration, eucalyptol was quickly absorbed by the brain. This study provides valuable information on eucalyptol use to treat illnesses of the central nervous system.


Assuntos
Barreira Hematoencefálica , Encéfalo , Ratos , Animais , Eucaliptol , Ratos Sprague-Dawley , Azul Evans/farmacologia
8.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 40(4): 753-761, 2023 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-37666766

RESUMO

It is a significant challenge to improve the blood-brain barrier (BBB) permeability of central nervous system (CNS) drugs in their development. Compared with traditional pharmacokinetic property tests, machine learning techniques have been proven to effectively and cost-effectively predict the BBB permeability of CNS drugs. In this study, we introduce a high-performance BBB permeability prediction model named balanced-stacking-learning based BBB permeability predictor(BSL-B3PP). Firstly, we screen out the feature set that has a strong influence on BBB permeability from the perspective of medicinal chemistry background and machine learning respectively, and summarize the BBB positive(BBB+) quantification intervals. Then, a combination of resampling algorithms and stacking learning(SL) algorithm is used for predicting the BBB permeability of CNS drugs. The BSL-B3PP model is constructed based on a large-scale BBB database (B3DB). Experimental validation shows an area under curve (AUC) of 97.8% and a Matthews correlation coefficient (MCC) of 85.5%. This model demonstrates promising BBB permeability prediction capability, particularly for drugs that cannot penetrate the BBB, which helps reduce CNS drug development costs and accelerate the CNS drug development process.


Assuntos
Algoritmos , Barreira Hematoencefálica , Área Sob a Curva , Bases de Dados Factuais , Permeabilidade
9.
Biochem Biophys Res Commun ; 597: 91-97, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35134610

RESUMO

The blood-brain barrier (BBB) remains a major obstacle for the delivery of drugs in the treatment of many neurological diseases. In this study, we aimed to investigate the effects of radiofrequency electromagnetic fields (RF-EMFs) on the permeability of an in vitro BBB model under RF exposure alone, or in the presence of nanoparticles (NPs). For this purpose, an in vitro BBB model was established by seeding human umbilical vein endothelial cells (HUVECs) and human glioblastoma cell line (T98G) on the apical and basolateral sides of the transwell membrane, respectively. The integrity of the BBB model was confirmed by measuring transendothelial electrical resistance (TEER), and a fluorescein isothiocyanate (FITC)-dextran permeability assay was performed when the resistance reached 120 Ω cm2. After the RF-field exposure (13.56 MHz, 80 W, 10 min), we found that FITC-dextran transported across the in vitro BBB was increased 10-fold compared to FITC-dextran transported without an RF-field. This notable phenomenon, which can be called the burst permeability RF effect (BP-RF), has been proposed for the first time in the literature. Subsequently, the effect of the RF-field on BBB permeability was also investigated in the presence of superparamagnetic iron oxide nanoparticles (SPIONs) and magnetic poly(lactic-co-glycolic acid)-polyethylene glycol (PLGA-b-PEG) nanoparticles (m-PNPs). It was found that the amount of both transported NPs on the basolateral sides increased after exposure to the RF-field. As a result, the RF-field can be applied simultaneously during treatment with clinical agents or nanocarriers, improving the permeability of the BBB, which may contribute to therapeutic efficacy of many drugs that are used in neurological diseases.

10.
Brain Behav Immun ; 102: 110-123, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35176443

RESUMO

High-fat diet (HFD) consumption leads to obesity and a chronic state of low-grade inflammation, named metainflammation. Notably, metainflammation contributes to neuroinflammation due to the increased levels of circulating free fatty acids and cytokines. It indicates a strict interplay between peripheral and central counterparts in the pathogenic mechanisms of obesity-related mood disorders. In this context, the impairment of internal hypothalamic circuitry runs in tandem with the alteration of other brain areas associated with emotional processing (i.e., hippocampus and amygdala). Palmitoylethanolamide (PEA), an endogenous lipid mediator belonging to the N-acylethanolamines family, has been extensively studied for its pleiotropic effects both at central and peripheral level. Our study aimed to elucidate PEA capability in limiting obesity-induced anxiety-like behavior and neuroinflammation-related features in an experimental model of HFD-fed obese mice. PEA treatment promoted an improvement in anxiety-like behavior of obese mice and the systemic inflammation, reducing serum pro-inflammatory mediators (i.e., TNF-α, IL-1ß, MCP-1, LPS). In the amygdala, PEA increased dopamine turnover, as well as GABA levels. PEA also counteracted the overactivation of HPA axis, reducing the expression of hypothalamic corticotropin-releasing hormone and its type 1 receptor. Moreover, PEA attenuated the immunoreactivity of Iba-1 and GFAP and reduced pro-inflammatory pathways and cytokine production in both the hypothalamus and hippocampus. This finding, together with the reduced transcription of mast cell markers (chymase 1 and tryptase ß2) in the hippocampus, indicated the weakening of immune cell activation underlying the neuroprotective effect of PEA. Obesity-driven neuroinflammation was also associated with the disruption of blood-brain barrier (BBB) in the hippocampus. PEA limited the albumin extravasation and restored tight junction transcription modified by HFD. To gain mechanistic insight, we designed an in vitro model of metabolic injury using human neuroblastoma SH-SY5Y cells insulted by a mix of glucosamine and glucose. Here, PEA directly counteracted inflammation and mitochondrial dysfunction in a PPAR-α-dependent manner since the pharmacological blockade of the receptor reverted its effects. Our results strengthen the therapeutic potential of PEA in obesity-related neuropsychiatric comorbidities, controlling neuroinflammation, BBB disruption, and neurotransmitter imbalance involved in behavioral dysfunctions.


Assuntos
Sistema Hipotálamo-Hipofisário , Doenças Neuroinflamatórias , Amidas , Animais , Ansiedade/tratamento farmacológico , Dieta Hiperlipídica , Etanolaminas , Sistema Hipotálamo-Hipofisário/metabolismo , Inflamação , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/complicações , Obesidade/metabolismo , Ácidos Palmíticos , Sistema Hipófise-Suprarrenal/metabolismo
11.
Nutr Neurosci ; 25(3): 485-501, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32406811

RESUMO

OBJECTIVE: Alzheimer's disease (AD) is an acquired neurological disorder of cognitive and behavioral impairments, with a long and progressive route. Currently, efforts are being made to develop potent drugs that target multiple pathological mechanisms that drive the successful treatment of AD in human beings. The development of nano-drug delivery systems has recently emerged as an effective strategy to treat AD. METHODS: In the present study, the protective effect of Phytol and Phytol loaded Poly Lactic-co-Glycolic Acid nanoparticles (Phytol-PLGANPs) were evaluated in Wistar rat scopolamine model of AD. RESULTS AND DISCUSSION: The consumption of Phytol and Phytol-PLGANPs significantly ameliorated the cognitive deficits caused by scopolamine on spatial and short term memory. Phytol and Phytol-PLGANPs significantly enhanced the cholinergic effect by inhibiting both acetylcholinesterase and butyrylcholinesterase (AChE & BuChE), ß-secretase 1 (BACE1) activity, attenuating macromolecular damage, reducing reactive oxygen species (ROS) and reactive nitrogen species (RNS) level by activating antioxidative defense system (Superoxide dismutase and catalase) and restoring glutathione metabolizing enzyme systems (Glutathione S-transferase) and also regulating the apoptotic mediated cell death. Moreover, in vivo toxicity study suggests that Phytol and Phytol-PLGANPs did not cause any adverse pathological alteration in rats treated with a higher concentration of Phytol-PLGANPs (200 mg/kg). Pharmacokinetic study revealed that Phytol-PLGANPs enhanced the biodistribution and sustained the release profile of phytol in the brain and plasma. CONCLUSION: Overall, the outcome of the study suggests that Phytol and Phytol-PLGANPs act as a potent candidate with better anti-amnesic effects and multi-faceted neuroprotective potential against scopolamine-induced memory dysfunction in Wistar rats.


Assuntos
Disfunção Cognitiva , Nanopartículas , Fármacos Neuroprotetores , Acetilcolinesterase/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Apoptose , Ácido Aspártico Endopeptidases/metabolismo , Ácido Aspártico Endopeptidases/farmacologia , Butirilcolinesterase/metabolismo , Butirilcolinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Inibidores da Colinesterase/toxicidade , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo , Fitol/farmacologia , Ratos , Ratos Wistar , Escopolamina , Distribuição Tecidual
12.
Handb Exp Pharmacol ; 271: 197-220, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34463847

RESUMO

Ligands for kappa opioid receptors (KOR) have potential uses as non-addictive analgesics and for the treatment of pruritus, mood disorders, and substance abuse. These areas continue to have major unmet medical needs. Significant advances have been made in recent years in the preclinical development of novel opioid peptides, notably ones with structural features that inherently impart stability to proteases. Following a brief discussion of the potential therapeutic applications of KOR agonists and antagonists, this review focuses on two series of novel opioid peptides, all-D-amino acid tetrapeptides as peripherally selective KOR agonists for the treatment of pain and pruritus without centrally mediated side effects, and macrocyclic tetrapeptides based on CJ-15,208 that can exhibit different opioid profiles with potential applications such as analgesics and treatments for substance abuse.


Assuntos
Antagonistas de Entorpecentes , Receptores Opioides kappa , Animais , Desenvolvimento de Medicamentos , Humanos , Ligantes , Camundongos , Camundongos Endogâmicos C57BL
13.
Int J Mol Sci ; 23(21)2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36361669

RESUMO

Quantitative structure-activity relationship (QSAR) and quantitative structure-property relationship (QSPR) are established techniques to relate endpoints to molecular features. We present the Alvascience software suite that takes care of the whole QSAR/QSPR workflow necessary to use models to predict endpoints for untested molecules. The first step, data curation, is covered by alvaMolecule. Features such as molecular descriptors and fingerprints are generated by using alvaDesc. Models are built and validated with alvaModel. The models can then be deployed and used on new molecules by using alvaRunner. We use these software tools on a real case scenario to predict the blood-brain barrier (BBB) permeability. The resulting predictive models have accuracy equal or greater than 0.8. The models are bundled in an alvaRunner project available on the Alvascience website.


Assuntos
Barreira Hematoencefálica , Relação Quantitativa Estrutura-Atividade , Fluxo de Trabalho , Permeabilidade , Software
14.
Molecules ; 27(7)2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35408519

RESUMO

Alzheimer's disease (AD) is a slowly progressive neurodegenerative disease that causes dementia in people aged 65 and over. In the present study, a series of thiadiazole hybrid compounds with benzothiazine derivatives as acetylcholinesterase inhibitors were developed and evaluated for their biological activity. The AChE and BChE inhibition potentials of all compounds were evaluated by using the in vitro Ellman method. The biological evaluation showed that compounds 3i and 3j displayed significant inhibitory activity against AChE. Compounds 3i and 3j showed IC50 values of 0.027 µM and 0.025 µM against AChE, respectively. The reference drug donepezil (IC50 = 0.021 µM) also showed significant inhibition against AChE. Further docking simulation also revealed that these compounds (3i and 3j) interacted with the active site of the enzyme similarly to donepezil. The antioxidant study revealed that compounds 3i and 3j exhibited greater antioxidant effects. An in vitro blood-brain barrier permeability study showed that compounds 3i and 3j are promising compounds against AD. The cytotoxicity study of compounds 3i and 3j showed non-cytotoxic with an IC50 value of 98.29 ± 3.98 µM and 159.68 ± 5.53 µM against NIH/3T3 cells, respectively.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Inibidores da Colinesterase/química , Donepezila/farmacologia , Desenho de Fármacos , Humanos , Camundongos , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade
15.
Can Assoc Radiol J ; 73(1): 194-202, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34154379

RESUMO

Hemorrhagic transformation is caused by extravasation of blood products from vessels after acute ischemic stroke. It is an undesirable and potentially devastating complication, which occurs in 10%-40% of clinical cases. Hemorrhagic transformation is classified into four subtypes based on European cooperative acute stroke study II. Predicting hemorrhagic complications at presentation can be useful life saving/altering decisions for the patient. Also, understanding the mechanisms of hemorrhagic transformation can lead to new treatments and intervention measures. We highlighted various imaging techniques that have been used to predict hemorrhagic transformation. Specifically, we looked at the usefulness of perfusion and permeability imaging for hemorrhagic transformation. Use of imaging to predict hemorrhagic transformation could change patient management that may lead to the prevention of hemorrhagic transformation before it occurs. We concluded that the current evidence is not strong enough to rely on these imaging parameters for predicting hemorrhagic transformation and more studies are required.


Assuntos
Isquemia Encefálica/complicações , Diagnóstico por Imagem/métodos , Hemorragia/diagnóstico por imagem , Acidente Vascular Cerebral/complicações , Encéfalo/diagnóstico por imagem , Isquemia Encefálica/diagnóstico por imagem , Hemorragia/etiologia , Humanos , Valor Preditivo dos Testes , Acidente Vascular Cerebral/diagnóstico por imagem
16.
J Infect Dis ; 223(9): 1612-1620, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-33320240

RESUMO

Human immunodeficiency virus (HIV) infection is associated with increased systemic microbial translocation, neuroinflammation, and occasionally, neuronal injury. Whether systemic lipopolysaccharide (LPS) penetrates into the brain and contributes to neuroinflammation remain unknown in HIV. Here, we measured plasma and cerebrospinal fluid (CSF) LPS levels along with biomarkers of neuroinflammation (white blood cell counts and 40 soluble markers) and neurofilament light chain (NfL). Notably, CSF LPS was undetectable in all samples, including 3 HIV-infected individuals with dementia. Increased plasma LPS, neuroinflammation, and blood-brain barrier (BBB) dysfunction were found in untreated HIV-infected individuals, but not in healthy or treated HIV-infected individuals. Plasma LPS levels were directly correlated with various markers of inflammation in both plasma and CSF, as well as with degree of BBB permeability but not with CSF NfL in HIV-infected subjects. These results suggest that the magnitude of microbial translocation associates with neuroinflammation and BBB permeability in HIV without direct penetration into the central nervous system.


Assuntos
Barreira Hematoencefálica , Infecções por HIV , Inflamação , Lipopolissacarídeos , Doenças Neuroinflamatórias , Biomarcadores , Infecções por HIV/complicações , HIV-1 , Humanos , Inflamação/complicações , Inflamação/virologia , Lipopolissacarídeos/sangue , Lipopolissacarídeos/líquido cefalorraquidiano , Doenças Neuroinflamatórias/complicações , Doenças Neuroinflamatórias/virologia , Permeabilidade
17.
Neuroimage ; 230: 117786, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33497771

RESUMO

Dynamic contrast-enhanced MRI (DCE-MRI) is increasingly used to quantify and map the spatial distribution of blood-brain barrier (BBB) leakage in neurodegenerative disease, including cerebral small vessel disease and dementia. However, the subtle nature of leakage and resulting small signal changes make quantification challenging. While simplified one-dimensional simulations have probed the impact of noise, scanner drift, and model assumptions, the impact of spatio-temporal effects such as gross motion, k-space sampling and motion artefacts on parametric leakage maps has been overlooked. Moreover, evidence on which to base the design of imaging protocols is lacking due to practical difficulties and the lack of a reference method. To address these problems, we present an open-source computational model of the DCE-MRI acquisition process for generating four dimensional Digital Reference Objects (DROs), using a high-resolution brain atlas and incorporating realistic patient motion, extra-cerebral signals, noise and k-space sampling. Simulations using the DROs demonstrated a dominant influence of spatio-temporal effects on both the visual appearance of parameter maps and on measured tissue leakage rates. The computational model permits greater understanding of the sensitivity and limitations of subtle BBB leakage measurement and provides a non-invasive means of testing and optimising imaging protocols for future studies.


Assuntos
Barreira Hematoencefálica/diagnóstico por imagem , Simulação por Computador , Meios de Contraste , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Doenças Neurodegenerativas/diagnóstico por imagem , Artefatos , Barreira Hematoencefálica/metabolismo , Permeabilidade Capilar/fisiologia , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/metabolismo , Meios de Contraste/metabolismo , Humanos , Modelos Neurológicos , Movimento (Física) , Doenças Neurodegenerativas/metabolismo
18.
Microvasc Res ; 137: 104193, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34062190

RESUMO

Sepsis is a complication of an infection which imbalance the normal regulation of several organ systems, including the central nervous system (CNS). Evidence points towards inflammation and oxidative stress as major steps associated with brain dysfunction in sepsis. Thus, we investigated the folic acid (FA) effect as an important antioxidant compound on acute brain dysfunction in rats and long term cognitive impairment and survival. Wistar rats were subjected to sepsis by cecal ligation and perforation (CLP) or sham (control) and treated orally with FA (10 mg/kg after CLP) or vehicle (veh). Animals were divided into sham + veh, sham + FA, CLP + veh and CLP + FA groups. Twenty-four hours after surgery, the hippocampus and prefrontal cortex were obtained and assayed for levels of blood brain barrier (BBB) permeability, nitrite/nitrate concentration, myeloperoxidase (MPO) activity, thiobarbituric acid reactive species (TBARS) formation and protein carbonyls. Survival was performed during 10 days after surgery and memory was evaluated. FA reduced BBB permeability, MPO activity in hippocampus and pre frontal cortex in 24 h and lipid peroxidation in hippocampus and improves the survival rate after sepsis. Long term cognitive improvement was verified with FA in septic rats compared with CLP + veh. Our data demonstrates that FA reduces the memory impairment in 10 days after sepsis and mortality in part by decreasing BBB permeability and oxidative stress parameters in the brain.


Assuntos
Antioxidantes/farmacologia , Comportamento Animal/efeitos dos fármacos , Barreira Hematoencefálica/efeitos dos fármacos , Permeabilidade Capilar/efeitos dos fármacos , Cognição/efeitos dos fármacos , Disfunção Cognitiva/prevenção & controle , Ácido Fólico/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Sepse/tratamento farmacológico , Animais , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/fisiopatologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Modelos Animais de Doenças , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Carbonilação Proteica/efeitos dos fármacos , Ratos Wistar , Sepse/metabolismo , Sepse/fisiopatologia , Sepse/psicologia
19.
Epilepsia ; 62(5): 1244-1255, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33818790

RESUMO

OBJECTIVE: Improving the identification of the epileptogenic zone and associated seizure-spreading regions represents a significant challenge. Innovative brain-imaging modalities tracking neurovascular dynamics during seizures may provide new disease biomarkers. METHODS: With use of a multi-parametric magnetic resonance imaging (MRI) analysis at 9.4 Tesla, we examined, elaborated, and combined multiple cellular and cerebrovascular MRI read-outs as imaging biomarkers of the epileptogenic and seizure-propagating regions. Analyses were performed in an experimental model of mesial temporal lobe epilepsy (MTLE) generated by unilateral intra-hippocampal injection of kainic acid (KA). RESULTS: In the ipsilateral epileptogenic hippocampi, tissue T1 and blood-brain barrier (BBB) permeability to gadolinium were increased 48-72 hours post-KA, as compared to sham and contralateral hippocampi. BBB permeability endured during spontaneous focal seizures (4-6 weeks), along with a significant increase of apparent diffusion coefficient (ADC) and blood volume fraction (BVf). Simultaneously, ADC and BVf were augmented in the contralateral hippocampus, a region characterized by electroencephalographic seizure spreading, discrete histological neurovascular cell modifications, and no tissue sclerosis. We next asked whether combining all the acquired MRI parameters could deliver criteria to classify the epileptogenic from the seizure-spreading and sham hippocampi in these experimental conditions and over time. To differentiate sham from epileptogenic areas, the automatic multi-parametric classification provided a maximum accuracy of 97.5% (32 regions) 48-72 hours post-KA and of 100% (60 regions) at spontaneous seizures stage. To differentiate sham, epileptogenic, and seizure-spreading areas, the accuracies of the automatic classification were 93.1% (42 regions) 48-72 hours post-KA and 95% (80 regions) at spontaneous seizure stage. SIGNIFICANCE: Combining multi-parametric MRI acquisition and machine-learning analyses delivers specific imaging identifiers to segregate the epileptogenic from the contralateral seizure-spreading hippocampi in experimental MTLE. The potential clinical value of our findings is critically discussed.


Assuntos
Mapeamento Encefálico/métodos , Epilepsia do Lobo Temporal/fisiopatologia , Processamento de Imagem Assistida por Computador/métodos , Aprendizado de Máquina , Imageamento por Ressonância Magnética Multiparamétrica/métodos , Animais , Modelos Animais de Doenças , Hipocampo/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
20.
Biol Pharm Bull ; 44(8): 1088-1092, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34334494

RESUMO

Clinically, neurological disorders, such as cognitive impairments and dementia, have been reported as diabetic complications, which are remarkable, especially in children with diabetes. The blood-brain barrier (BBB) is a physiologically dynamic regulatory barrier that maintains the consistency of the fluid microenvironment composition of the brain. However, the differences in BBB conditions between children and adults and the contribution of the BBB to the severity of cognitive impairments remain unclear. We generated adult-onset diabetes mellitus (DM) and juvenile-onset diabetes mellitus (JDM) diabetic rat models and investigated BBB functions in these models during the early stages of type 1 diabetes. We performed a BBB permeability assay using sodium fluorescein, a small-molecule fluorescent dye, to evaluate endothelial transport from the blood to the central nervous system. One week after diabetes onset, BBB permeability increased in the hippocampus and striatum of JDM rats, but no changes were observed in the frontal cortex and hypothalamus of JDM rats or for any region of DM rats. The double staining of tight junction proteins and astrocytes revealed no changes in the hippocampus and striatum of JDM rats. These results suggested that the observed increase in BBB permeability during early-stage diabetes onset in JDM rats, which did not depend on the expression of the interendothelial tight junction protein, claudin-5, may affect stylized neural development and cognitive function.


Assuntos
Barreira Hematoencefálica/fisiopatologia , Complicações do Diabetes/fisiopatologia , Diabetes Mellitus Tipo 1/fisiopatologia , Fluoresceína/metabolismo , Adulto , Idade de Início , Animais , Transporte Biológico , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Encéfalo/fisiologia , Encéfalo/fisiopatologia , Criança , Disfunção Cognitiva/fisiopatologia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/metabolismo , Células Endoteliais , Feminino , Humanos , Masculino , Permeabilidade , Ratos Wistar , Proteínas de Junções Íntimas/metabolismo
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