Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Neural Netw ; 171: 53-60, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38091764

RESUMO

This paper presents a delay-variation-dependent approach to fault detection of a discrete-time Markov jump neural network (MJNN) with a time-varying delay and mismatched modes. The goal is to detect the potential fault of delayed MJNNs by constructing an appropriate adaptive event-triggered and asynchronous H∞ filter. By choosing a delay-product-type Lyapunov-Krasovskii (L-K) functional with a delay-dependent matrix and exploiting some matrix polynomial inequalities, bounded real lemmas (BRLs) are obtained on the existence of suitable adaptive event generator and filters. These BRLs are dependent not only on the delay bounds but also on the delay variation rate. Simulation results are given to show the validity of the proposed theoretical method.


Assuntos
Algoritmos , Redes Neurais de Computação , Fatores de Tempo , Simulação por Computador
2.
Int J Biol Macromol ; 256(Pt 1): 128370, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38000594

RESUMO

Infection poses a significant barrier to effective wound repair, leading to increased inflammatory responses that ultimately result in incomplete and prolonged wound healing. To address this challenge, numerous antibacterial ingredients have been incorporated into dressings to inhibit wound infection. Our previous work demonstrated that lysozyme/silver nanoparticles (LYZ/AgNPs) complexes, prepared using an eco-friendly one-step aqueous method, exhibited excellent antibacterial efficacy with favorable biosafety. To further explore its potential application in advancing wound healing, calcium alginate (CA) with good porosity, water absorption, and water retention capacities was formulated with LYZ/AgNPs to prepare composite sponge (CA/LYZ/AgNPs). As expected, in vivo experiments involving full-thickness skin wound and scald wound healing experiments demonstrated that CA-LYZ-AgNPs composite sponges with excellent biocompatibility exhibited remarkable antibacterial activity against gram-positive bacteria, gram-negative bacteria and fungi, and outperformed the wound healing process efficacy of other commercially available AgNPs-loaded wound dressings. In summary, this work introduces a CA/LYZ/AgNPs sponge featuring exceptional antibacterial efficacy and biocompatibility, thus holding promising potential in wound care applications.


Assuntos
Alginatos , Nanopartículas Metálicas , Alginatos/farmacologia , Prata/farmacologia , Muramidase , Antibacterianos/farmacologia , Cicatrização , Bandagens , Água
3.
Food Funct ; 14(10): 4621-4631, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37158592

RESUMO

The abnormal accumulation of fused in sarcoma (FUS) is a pathological hallmark in a proportion of patients with frontotemporal dementia and amyotrophic lateral sclerosis. Therefore, the clearance of FUS aggregates is a possible therapeutic strategy for FUS-associated neurodegenerative diseases. This study reports that curcumin can strongly suppress FUS droplet formation and stress granule aggregation of FUS. Fluorescence spectra and isothermal titration calorimetry showed that curcumin can bind FUS through hydrophobic interactions, thereby reducing the ß-sheet content of FUS. Aggregated FUS sequesters pyruvate kinase, leading to reduced ATP levels. However, results from a metabolomics study revealed that curcumin changed the metabolism pattern and differentially expressed metabolites were enriched in glycolysis. Curcumin attenuated FUS aggregation-mediated sequestration of pyruvate kinase and restored cellular metabolism, consequently increasing ATP levels. These results indicate that curcumin is a potent inhibitor of FUS liquid-liquid phase separation and provide novel insights into the effect of curcumin in ameliorating abnormal metabolism.


Assuntos
Curcumina , Demência Frontotemporal , Sarcoma , Humanos , Piruvato Quinase/genética , Piruvato Quinase/metabolismo , Curcumina/farmacologia , Demência Frontotemporal/metabolismo , Trifosfato de Adenosina , Mutação , Proteína FUS de Ligação a RNA/química , Proteína FUS de Ligação a RNA/genética , Proteína FUS de Ligação a RNA/metabolismo
4.
Neurol Ther ; 12(4): 1385-1398, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37195410

RESUMO

INTRODUCTION: This prospective observational study with a control group aimed to compare the plasma levels of long non-coding RNA (lncRNA) LIPCAR between patients with acute cerebral infarction (ACI) and healthy controls, and to assess the prognostic abilities of LIPCAR for adverse outcomes of patients with ACI at 1-year follow-up. METHODS: Eighty patients with ACI, of whom 40 had large artery atherosclerosis (LAA) and 40 had cardioembolism (CE) and who were hospitalized at Xi'an No. 1 Hospital from July 2019 to June 2020, were selected as the case group. Age- and sex-matched non-stroke patients from the same hospital throughout the same time period were chosen as the control group. Real-time quantitative reverse transcription polymerase chain reaction was used to measure the levels of plasma lncRNA LIPCAR. The correlations of LIPCAR expression among the LAA, CE, and control groups were assessed using Spearman's correlation analysis. Curve fitting and multivariate logistic regression were used to analyze the LIPCAR levels and 1-year adverse outcomes of patients with ACI and its subtypes. RESULTS: The expression of plasma LIPCAR in the case group was noticeably higher than that of the control group (2.42 ± 1.49 vs. 1.00 ± 0.47, p < 0.001). Patients with CE had considerably higher levels of LIPCAR expression than those with LAA. The National Institute of Health Stroke Scale score and modified Rankin scale score on admission were significantly positively correlated with LIPCAR expression in patients with CE and LAA. Furthermore, the correlation was stronger in patients with CE than in those with LAA, with correlation coefficients of 0.69 and 0.64, respectively. Curve fitting revealed a non-linear correlation between LIPCAR expression levels, 1-year recurrent stroke, all-cause mortalities, and poor prognoses, with a cut-off value of 2.2. CONCLUSION: The expression level of lncRNA LIPCAR may play a potential role in the identification of neurological impairment and CE subtype in patients with ACI. Increased 1-year risk of adverse outcomes may be associated with high levels of LIPCAR expression.


Acute cerebral infarction is the second-leading cause of death worldwide. Therefore, available diagnostic and prognostic tools are of the utmost importance. It is easy to acquire hematologic biomarkers and to provide direct information related to the severity of brain injury and the risk of stroke. However, it has been shown that the study of hematologic markers in aspects of both identifying stroke subtypes and predicting neurological impairment are still few and imperfect in clinical application of stroke prognosis. The long non-coding RNA LIPCAR plays an important role in the pathophysiology of cardiovascular disease. Nonetheless, to date, no exploration has been carried out on the correlation between lncRNA LIPCAR, severity on admission, and prognosis of stroke subtypes. Thus, this study aimed to investigate the plasma levels of lncRNA LIPCAR expression and their correlations in patients with acute cerebral infarction and its subtypes. Our results show that the plasma levels of LIPCAR expression of the patients with acute cerebral infarction were noticeably higher than those of the non-stroke control patients. Patients with cardioembolism subtype had considerably higher levels of LIPCAR expression than those with large artery atherosclerosis. The National Institute of Health Stroke Scale score and modified Rankin scale score on admission were significantly correlated with LIPCAR expression in patients with cardioembolism and large artery atherosclerosis; the correlation was stronger in patients with cardioembolism than in patients with large artery atherosclerosis, with correlation coefficients of 0.69 and 0.64, respectively. Furthermore, curve fitting revealed a non-linear correlation between LIPCAR expression levels and 1-year outcome events. The expression level of lncRNA LIPCAR may play a potential role in the identification of neurological impairment and cardioembolism subtype in patients with acute cerebral infarction.

5.
Research (Wash D C) ; 6: 0146, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37228640

RESUMO

The biological effects of magnetic fields (MFs) have been a controversial issue. Fortunately, in recent years, there has been increasing evidence that MFs do affect biological systems. However, the physical mechanism remains unclear. Here, we show that MFs (16 T) reduce apoptosis in cell lines by inhibiting liquid-liquid phase separation (LLPS) of Tau-441, suggesting that the MF effect on LLPS may be one of the mechanisms for understanding the "mysterious" magnetobiological effects. The LLPS of Tau-441 occurred in the cytoplasm after induction with arsenite. The phase-separated droplets of Tau-441 recruited hexokinase (HK), resulting in a decrease in the amount of free HK in the cytoplasm. In cells, HK and Bax compete to bind to the voltage-dependent anion channel (VDAC I) on the mitochondrial membrane. A decrease in the number of free HK molecules increased the chance of Bax binding to VDAC I, leading to increased Bax-mediated apoptosis. In the presence of a static MF, LLPS was marked inhibited and HK recruitment was reduced, resulting in an increased probability of HK binding to VDAC I and a decreased probability of Bax binding to VDAC I, thus reducing Bax-mediated apoptosis. Our findings revealed a new physical mechanism for understanding magnetobiological effects from the perspective of LLPS. In addition, these results show the potential applications of physical environments, such as MFs in this study, in the treatment of LLPS-related diseases.

6.
Biomacromolecules ; 24(1): 1-18, 2023 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-36507729

RESUMO

Amyloid protein cross-seeding is a peculiar phenomenon of cross-spreading among different diseases. Unlike traditional infectious ones, diseases caused by amyloid protein cross-seeding are spread by misfolded proteins instead of pathogens. As a consequence of the interactions among misfolded heterologous proteins or polypeptides, amyloid protein cross-seeding is considered to be the crucial cause of overlapping pathological transmission between various protein misfolding disorders (PMDs) in multiple tissues and cells. Here, we briefly review the phenomenon of cross-seeding among amyloid proteins. As an interesting example worth mentioning, the potential links between the novel coronavirus pneumonia (COVID-19) and some neurodegenerative diseases might be related to the amyloid protein cross-seeding, thus may cause an undesirable trend in the incidence of PMDs around the world. We then summarize the theoretical models as well as the experimental techniques for studying amyloid protein cross-seeding. Finally, we conclude with an outlook on the challenges and opportunities for basic research in this field. Cross-seeding of amyloid opens up a new perspective in our understanding of the process of amyloidogenesis, which is crucial for the development of new treatments for diseases. It is therefore valuable but still challenging to explore the cross-seeding system of amyloid protein as well as to reveal the structural basis and the intricate processes.


Assuntos
COVID-19 , Doenças Neurodegenerativas , Humanos , Proteínas Amiloidogênicas , Peptídeos beta-Amiloides/química , Amiloide/metabolismo
7.
Cardiovasc J Afr ; 34(4): 256-259, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36044199

RESUMO

Kounis syndrome is defined as an acute coronary syndrome (ACS) secondary to allergic or hypersensitivity reactions. It can be further categorised into subtypes such as coronary vasospasms, acute myocardial infarction or stent thrombosis based on the pathogenesis. Kounis syndrome is most likely an underdiagnosed condition in China, given the many triggers reported in the literature. Herein, we report a case of Kounis syndrome, possibly triggered by a bee sting. The patient had late onset of angina symptoms with delayed diagnosis due to unfamiliarity with this condition. In patients with clinical signs of ACS that are superimposed on a hypersensitivity reaction, especially those with pre-existing cardiovascular risk factors, Kounis syndrome should be considered, so that appropriate assessment and treatment can be initiated. Prompt management of both the allergic reaction and the ACS is vital for Kounis syndrome.


Assuntos
Síndrome Coronariana Aguda , Hipersensibilidade , Mordeduras e Picadas de Insetos , Síndrome de Kounis , Infarto do Miocárdio , Animais , Humanos , Abelhas , Síndrome de Kounis/diagnóstico , Síndrome de Kounis/etiologia , Síndrome de Kounis/terapia , Mordeduras e Picadas de Insetos/complicações , Mordeduras e Picadas de Insetos/diagnóstico , Hipersensibilidade/etiologia , Infarto do Miocárdio/complicações , Angina Pectoris , Síndrome Coronariana Aguda/diagnóstico por imagem , Síndrome Coronariana Aguda/etiologia
8.
Int J Pharm ; 627: 122200, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36155893

RESUMO

Staphylococcus aureus (S. aureus) infection, especially its drug-resistant bacterial infection, is a great challenge often faced by clinicians and patients, and it is also one of the most important threats to public health. Finding a safe and effective antibacterial agent is of great significance for the prevention and treatment of S. aureus infection. Lysozyme is known to have antibacterial effects against Gram-positive bacteria including S. aureus. Here, high-quality lysozyme with a purity of more than 99% and an activity of more than 60, 000 U/mg was prepared from egg white, which showed excellent antibacterial activity against three strains of S. aureus, especially against MRSA. Furthermore, an antibacterial cream loaded with lysozyme was prepared and tested in scald wound healing. The lysozyme-loaded cream exhibited the effect of preventing wound infection and promoting wound healing on scalds, and no toxicity was found in animal organs. Overall, lysozyme showed great application potential in the prevention and treatment of infections caused by S. aureus and scalded wound healing. The most remarkable discovery in this work is the unexpectedly powerful inhibitory effect of lysozyme on the drug-resistant bacterial, especially MRSA, which is usually very difficult to deal with using normal antibacterial drugs.


Assuntos
Queimaduras , Fármacos Dermatológicos , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Animais , Staphylococcus aureus , Testes de Sensibilidade Microbiana , Muramidase/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Cicatrização , Fármacos Dermatológicos/farmacologia , Queimaduras/tratamento farmacológico
9.
IEEE Trans Cybern ; 52(5): 3359-3369, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-32784148

RESUMO

In this article, the fault detection (FD) filter design problem is addressed for discrete-time memristive neural networks with time delays. When constructing the system model, an event-triggered communication mechanism is investigated to reduce the communication burden and a fault weighting matrix function is adopted to improve the accuracy of the FD filter. Then, based on the Lyapunov functional theory, an augmented Lyapunov functional is constructed. By utilizing the summation inequality approach and the improved reciprocally convex combination method, an FD filter that guarantees the asymptotic stability and the prescribed H∞ performance level of the residual system is designed. Finally, numerical simulations are provided to illustrate the effectiveness of the presented results.


Assuntos
Comunicação , Redes Neurais de Computação , Fatores de Tempo
10.
ACS Appl Mater Interfaces ; 13(39): 46391-46405, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34570465

RESUMO

Proteins are like miracle machines, playing important roles in living organisms. They perform vital biofunctions by further combining together and/or with other biomacromolecules to form assemblies or condensates such as membraneless organelles. Therefore, studying the self-assembly of biomacromolecules is of fundamental importance. In addition to their biological activities, protein assemblies also exhibit extra properties that enable them to achieve applications beyond their original functions. Herein, this study showed that in the presence of monosaccharides, ethylene glycols, and amino acids, ß-lactoglobulin (ß-LG) can form assemblies with specific structures, which were highly reproducible. The mechanism of the assembly process was studied through multi-scale observations and theoretical analysis, and it was found that the assembling all started from the formation of solute-rich liquid droplets via liquid-liquid phase separation (LLPS). These droplets then combined together to form condensates with elaborate structures, and the condensates finally evolved to form assemblies with various morphologies. Such a mechanism of the assembly is valuable for studying the assembly processes that frequently occur in living organisms. Detailed studies concerning the properties and applications of the obtained ß-LG assemblies showed that the assemblies exhibited significantly better performances than the protein itself in terms of autofluorescence, antioxidant activity, and metal ion absorption, which indicates broad applications of these assemblies in bioimaging, biodetection, biodiagnosis, health maintenance, and pollution treatment. This study revealed that biomacromolecules, especially proteins, can be assembled via LLPS, and some unexpected application potentials could be found beyond their original biological functions.


Assuntos
Antioxidantes/metabolismo , Quelantes/metabolismo , Lactoglobulinas/metabolismo , Animais , Antioxidantes/química , Quelantes/química , Cobre/química , Ligação de Hidrogênio , Ferro/química , Lactoglobulinas/química , Chumbo/química , Camundongos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Multimerização Proteica , Células RAW 264.7
11.
Int J Ophthalmol ; 14(4): 489-496, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33875937

RESUMO

AIM: To investigate YM155's effect on retinal pigment epithelium (RPE) cells' viability and the potential regulatory mechanisms. METHODS: Human immortalized RPE cell lines (ARPE-19 cell line) were processed with YM155 and epidermal growth factor (EGF). ARPE-19 cell viability was detected by methyl thiazolyl tetrazolium assay, and apoptosis was tested by flow cytometry assay. ARPE-19 cell proliferation was assessed with bromodeoxyuridine tagged incorporation assay, and migration ability was evaluated via a wound-healing assay. Epidermal growth factor receptor (EGFR)/MAPK pathway proteins were tested via immunoblotting. EGFR localization was examined by immunofluorescence assay. RESULTS: YM155 suppressed ARPE-19 cells' viability in a time and concentration-dependent manner. A high dose of YM155 caused a small amount of ARPE-19 cell death. YM155 significantly diminished the ARPE-19 cells' proliferative and migrative capacity. YM155 down-regulated total EGFR and phosphorylated external signal-regulated protein kinase (ERK), and it up-regulated the phosphorylation of P38MAPK and c-Jun N-terminal kinase (JNK). YM155 induced endocytosis of EGFR in ARPE-19 cell. YM155 also attenuated EGF-induced ARPE-19 cells' proliferative and migrative capacity. Moreover, YM155 significantly decreased the expression of phosphorylated EGFR and ERK after treated by EGF. CONCLUSION: YM155 inhibits RPE cell survival, the cell proliferative and migrative capacity, and it effectuates a small amount of cell death through the EGFR/MAPK signaling pathway. YM155 might, therefore, be an agent to prevent and treat abnormal RPE cell survival in proliferative vitreoretinopathy.

12.
Appl Microbiol Biotechnol ; 105(7): 2759-2773, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33683398

RESUMO

The self-assembly of biomacromolecules is an extremely important process. It is potentially useful in the fields of life science and materials science. To carry out the study on the self-assembly of proteins, it is necessary to find out the suitable self-assembly conditions, which have always been a challenging task in practice. Inspired by the screening technique in the field of protein crystallization, we proposed using the same screening technique for seeking suitable protein self-assembly conditions. Based on this consideration, we selected 5 proteins (ß-lactoglobulin, hemoglobin, pepsin, lysozyme, α-chymotrypsinogen (II) A) together with 5 screening kits (IndexTM, BML, Morpheus, JCSG, PEG/Ion ScreenTM) to investigate the performance of these crystallization screening techniques in order to discover new optimized conditions of protein self-assembly. The screens were all kept at 293 K for certain days, and were analyzed using optical microscope, scanning electron microscope, transmission electron microscope, atomic force microscope, fluorescence microscope, and atomic absorption spectroscope. The results demonstrated that the method of protein crystallization screening can be successfully applied in the screening of self-assembly conditions. This method is fast, high throughput, and easily implemented in an automated system, with a low protein consumption feature. These results suggested that such strategy can be applied to finding new conditions or forms in routine research of protein self-assembly. KEY POINTS: • Protein crystallization screening method is successfully applied in the screening of self-assembly conditions. • This screening method can be applied on various kinds of proteins and possess a feature of low protein consumption. • This screening method is fast, high throughput, and easily implemented in an automated system.


Assuntos
Proteínas , Cristalização
13.
IEEE Trans Cybern ; 51(3): 1311-1321, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31425061

RESUMO

This paper is concerned with the problem of reachable set estimation for discrete-time Markovian jump neural networks with generally incomplete transition probabilities (TPs). This kind of TP may be exactly known, merely known with lower and upper bounds, or unknown. The aim of this paper is to derive a precise reachable set description for the considered system via the Lyapunov-Krasovskii functional (LKF) approach. By constructing an augmented LKF, using an equivalent transformation method to deal with the unknown TPs and utilizing the extended reciprocally convex matrix inequality, and the free matrix weighting approach to estimate the forward difference of the constructed LKF, several sufficient conditions that guarantee the existence of an ellipsoidal reachable set are established. Finally, a numerical example with simulation results is given to demonstrate the effectiveness and superiority of the proposed results.

14.
IEEE Trans Neural Netw Learn Syst ; 31(12): 5456-5467, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32071007

RESUMO

In this article, the finite-time H∞ state estimation problem is addressed for a class of discrete-time neural networks with semi-Markovian jump parameters and time-varying delays. The focus is mainly on the design of a state estimator such that the constructed error system is stochastically finite-time bounded with a prescribed H∞ performance level via finite-time Lyapunov stability theory. By constructing a delay-product-type Lyapunov functional, in which the information of time-varying delays and characteristics of activation functions are fully taken into account, and using the Jensen summation inequality, the free weighting matrix approach, and the extended reciprocally convex matrix inequality, some sufficient conditions are established in terms of linear matrix inequalities to ensure the existence of the state estimator. Finally, numerical examples with simulation results are provided to illustrate the effectiveness of our proposed results.


Assuntos
Análise de Elementos Finitos , Cadeias de Markov , Redes Neurais de Computação , Processos Estocásticos , Algoritmos
15.
IEEE Trans Neural Netw Learn Syst ; 30(8): 2528-2537, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30605107

RESUMO

This paper investigates the problem of extended dissipativity for Markovian jump neural networks (MJNNs) with a time-varying delay. The objective is to derive less conservative extended dissipativity criteria for delayed MJNNs. Toward this aim, an appropriate Lyapunov-Krasovskii functional (LKF) with some improved delay-product-type terms is first constructed. Then, by employing the extended reciprocally convex matrix inequality (ERCMI) and the Wirtinger-based integral inequality to estimate the derivative of the constructed LKF, a delay-dependent extended dissipativity condition is derived for the delayed MJNNs. An improved extended dissipativity criterion is also given via the allowable delay sets method. Based on the above-mentioned results, the extended dissipativity condition of delayed NNs without Markovian jump parameters is directly derived. Finally, three numerical examples are employed to illustrate the advantages of the proposed method.


Assuntos
Cadeias de Markov , Redes Neurais de Computação , Algoritmos , Fatores de Tempo
16.
Neural Netw ; 108: 527-532, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30336327

RESUMO

This paper is concerned with the reachable set estimation for Markovian jump neural networks with time-varying delay and bounded peak inputs. The objective is to find a description of a reachable set that is containing all reachable states starting from the origin. In the framework of Lyapunov-Krasovskii functional method, an appropriate Lyapunov-Krasovskii functional is constructed firstly. Then by using the Wirtinger-based integral inequality and the extended reciprocally convex matrix inequality, an ellipsoidal description of the reachable set for the considered neural networks is derived. Finally, a numerical example with simulation results is provided to verify the effectiveness of our results.


Assuntos
Cadeias de Markov , Redes Neurais de Computação , Algoritmos , Simulação por Computador , Fatores de Tempo
17.
Front Cell Neurosci ; 12: 255, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30135647

RESUMO

Recent studies indicate that disturbed structure and function of microglia can cause depression and associated neurogenesis impairments. Our previous work has demonstrated that exogenous fibroblast growth factor 2 (FGF2) reverses the depressive-like behaviors and the impaired hippocampal neurogenesis in a neuroinflammatory model of depression. However, whether and how the antidepressant effects of FGF2 involve the modulation of microglia activation has not been elucidated. In this study, to examine the effects of FGF2 on microglia activation, exogenous FGF2 was supplemented to the lateral ventricle of rats during the neuroinflammatory state induced by central lipopolysaccharides (LPS) administrations. It was found that FGF2 infusions reversed the LPS-induced depressive-like behaviors and inhibited the hippocampal microglia activation. In LPS-treated rats, FGF2 decreased the level of pro-inflammatory cytokines including interlukin-1ß (IL-1ß), IL-6 and tumor necrosis factor (TNF)-α, increased the level of IL-10, the anti-inflammatory cytokine and reversed the decreased expression of CX3CL1, a chemokine mainly expressed by neurons and keeping microglia in surveillance. Further, we examined the effects of inhibited FGF2 signaling by administration of SU5402, an FGFR inhibitor. It was found that SU5402 itself evoked depressive-like behaviors, induced microglia activation, increased production of pro-inflammatory cytokines including IL-1ß, IL-6 and TNF-α, and decreased the expression of CX3CL1. Two lines of results that FGF2 signaling and FGFR inhibitor can effectively but oppositely modulate the regulation of microglia and the generation of depressive-like behavior, suggesting that microglia-regulated mechanisms may underlie the antidepressant role of FGF2. The present data provide novel insights into the understanding of mechanism of neuroinflammation-associated depression and may serve as a novel mechanism-based target for the treatment of inflammation-related depression.

18.
Front Pharmacol ; 9: 511, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29867510

RESUMO

Increasing evidence has demonstrated that neuroinflammation contributes to the development of depressive-like behaviors, in both animal models and human patients; however, the brain areas and signaling pathways involved are still elusive. Recent studies have suggested novel roles of the habenula in the onset of depression and other psychiatric disorders; however, there is no evidence for whether the habenula has a function in neuroinflammation-induced depression. Using an animal model of depression, which is induced by the repeated central administration of lipopolysaccharide (LPS), we examined whether cytokine expression and p38 signal activation in the habenula were involved in the depressive-like behaviors. Body weight, saccharin preference test, and tail suspension test were used to measure depressive-like behaviors. Immunohistochemistry, quantitative-polymerase chain reaction (q-PCR), and western blot were used to measure the expression of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), and the phosphorylation of p38 in the habenula. The results showed that central LPS administration induced depressive-like behaviors, characterized by anhedonia in the saccharin preference test and increased immobility in the tail suspension test. Central LPS administration also significantly increased the p-p38 level in microglial cells and increased TNF-α expression in the habenula. Treatment with fluoxetine, a widely prescribed antidepressant, or SB203580, a p38-specific inhibitor, reversed the depressive-like behaviors, normalized the alterations in p-p38 and TNF-α levels and increased the levels of the anti-inflammatory cytokine IL-10 in the habenula. The present findings suggest that the habenula is involved in the pathophysiology of behavioral depression induced by neuroinflammation, and the p38 pathway may serve as a novel mechanism-based target for the treatment of inflammation-related depression.

19.
IEEE Trans Neural Netw Learn Syst ; 29(9): 4487-4493, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-28981434

RESUMO

This brief is concerned with global asymptotic stability of a neural network with a time-varying delay. First, by introducing an auxiliary vector with some nonorthogonal polynomials, a slack-matrix-based integral inequality is established, which includes some existing one as its special case. Second, a novel Lyapunov-Krasovskii functional is constructed to suit for the use of the obtained integral inequality. As a result, a less conservative stability criterion is derived, whose effectiveness is finally demonstrated through two well-used numerical examples.

20.
Brain Behav Immun ; 66: 322-331, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28529071

RESUMO

Our previous work demonstrated that neuroinflammation evoked by triple repeated central LPS challenges inhibited adult hippocampal neurogenesis that were correlated with the depressive-like behavioral symptoms induced by neuroinflammation. These findings suggest that hippocampal neurogenesis might be one of biological mechanisms underlying depression induced by neuroinflammation and targeting neurogenesis might lead to new therapeutic strategies for the treatment of depression. In this study, we manipulated adult hippocampal neurogenesis using fibroblast growth factor 2 (FGF2), one crucial molecule modulating cell proliferation and survival in central nervous system, and investigate the involvement and the potential therapeutic effects of FGF2 on neuroinflammation-induced depression. Central lipopolysaccharides (LPS) challenges were used as previously to evoke the neuroinflammatory state in the brain of rat. Exogenous FGF2 was infused into lateral ventricle during the neuroinflammatory state. It was found that the protein expression of FGF2 in hippocampus was inhibited by neuroinflammation. The activation of extracellular signal-regulated kinase (ERK), the downstream molecule of FGF2, was also inhibited by neuroinflammation. Exogenous FGF2 infusions prevented the decrease in phosphorylation of ERK1/2 under neuroinflammation state. Exogenous FGF2 reversed depressive-like behaviors and the impaired hippocampal neurogenesis induced by neuroinflammation. These findings provide evidence that the FGF2-ERK1/2 pathway is involved in the pathophysiology of depressive-like behaviors, and manipulating the neurogenesis pathway is a viable therapeutic approach to inflammation-associated depression.


Assuntos
Depressão/metabolismo , Encefalite/metabolismo , Fator 2 de Crescimento de Fibroblastos/administração & dosagem , Fator 2 de Crescimento de Fibroblastos/metabolismo , Hipocampo/metabolismo , Sistema de Sinalização das MAP Quinases , Neurogênese , Animais , Depressão/prevenção & controle , Encefalite/induzido quimicamente , Lipopolissacarídeos/administração & dosagem , Masculino , Fosforilação , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA