scholarly journals Dexamethasone promotes IL-4-induced alternative activation at PPARγ point, instead of upstream STAT6 in BV2 microglial cells

2020 ◽  
Author(s):  
Zongfeng Chen ◽  
Liang Zhang ◽  
Xin Xue ◽  
Peng Liu ◽  
Xiang Yin ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Therapeutic Potential ◽  
Polarization State ◽  
Microglial Cells ◽  
Alternative Activation ◽  
Peroxisome Proliferator ◽  
Activation Markers ◽  
Arginase 1 ◽  
The Central Nervous System

Abstract Background Microglia are innate immune effector cells in the central nervous system and play an extremely important role in the physiological processes of the central nervous system. When microglia are activated, there are two polarization states, M1 and M2 phenotype. Dexamethasone is a glucocorticoid widely used in clinical practice, which pharmacological effects are mainly anti-inflammatory, anti-toxic. However, whether Dexamethasone affects polarization state of microglia is unknown. In this study, we investigate the effect of Dexamethasone on IL-4-induced alternative activation in murine BV-2 microglial cells. Methods BV-2 cells were incubated with Dexamethasone alone, IL-4 alone, or the combination of Dexamethasone and IL-4. Western blot and immunofluorescence were performed to detect protein levels of alternative activation markers arginase 1 (Arg1), found in inflammatory zone 1 (FIZZ1). Moreover, we investigated the effects of Dexamethasone on IL-4 induced activation of signal transducer and activators of transcription 6 (STAT6) and peroxisome proliferator-activated receptor-gamma (PPARγ). Results Dexamethasone promoted IL-4 induced microglia alternative activation by increasing the expression of Arg1 and FIZZ1. Dexamethasone also enhanced the expression of PPARγ. These effects were reversed by RU486 (a Dexamethasone antagonist). Further, the effects of Dexamethasone and IL-4 on Arg1 and FIZZ1 were blocked by the application of GW9662 (a PPARγ antagonist). Conclusions Our studies confirm that Dexamethasone promotes IL-4 induced alternative activation via STAT6/PPARγ signaling pathways in microglia. At the same time, it was confirmed that Dexamethasone acts on PPARγ instead of STAT6. These findings support that Dexamethasone has a therapeutic potential for neuroinflammatory diseases via alternative activation.

scholarly journals Peroxisome proliferator-activated receptor α and γ agonists differently regulate classical and alternative macrophage activation

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Erja-Leena Paukkeri ◽  
Antti Pekurinen ◽  
Eeva Moilanen
Keyword(s):  
Macrophage Activation ◽  
Inflammatory Responses ◽  
Therapeutic Potential ◽  
Alternative Activation ◽  
Peroxisome Proliferator ◽  
Activation Markers ◽  
Peroxisome Proliferator Activated Receptor ◽  
Arginase 1 ◽  
Pparγ Agonist ◽  
Ppar Agonists

AbstractPeroxisome proliferator-activated receptor (PPAR) agonists, fibrates and thiazolidinediones, are commonly used drugs in the treatment of dyslipidemia and diabetes. Their targets, PPARα and PPARγ, have also been shown to have a role in the regulation of inflammatory responses linking metabolism and inflammation. In the present study we investigated the effects of PPAR agonists on macrophage activation. In addition to the proinflammatory classical activation, we also focused on interleukin (IL) 4 and 13 -induced alternative activation which is a significant macrophage phenotype in tissue repairing processes and in fibrosing diseases. PPARα agonists GW7647 and fenofibrate as well as PPARγ agonist GW1929 inhibited lipopolysaccharide-induced classical macrophage activation and production of the characteristic biomarkers of this phenotype, i.e. IL-6 and nitric oxide, in murine J774 macrophages. Remarkably, the PPARα agonists also inhibited IL-4 and IL-13 –induced expression of alternative activation markers arginase-1, fizz1 and mannose receptor 1 whereas the PPARγ agonist GW1929 enhanced their expression in J774 macrophages. The PPARα agonists GW7647 and fenofibrate also attenuated the production of alternative activation markers chemokine (C-C motif) ligand 13 and plateletderived growth factor in human THP-1 macrophages. The present findings show that PPARα and PPARγ agonists differently regulate classical and alternative macrophage phenotypes. Furthermore, PPARα activation was introduced as a novel concept to down-regulate alternative macrophage activation indicating that PPARα agonists have therapeutic potential in conditions associated with aberrant alternative macrophage activation such as fibrosing diseases.

RAS in the Central Nervous System: Potential Role in Neuropsychiatric Disorders

2018 ◽  
Vol 25 (28) ◽  
pp. 3333-3352 ◽  
Author(s):  
Natalia Pessoa Rocha ◽  
Ana Cristina Simoes e Silva ◽  
Thiago Ruiz Rodrigues Prestes ◽  
Victor Feracin ◽  
Caroline Amaral Machado ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Central Nervous System ◽  
Nervous System ◽  
Therapeutic Potential ◽  
Neuropsychiatric Disorders ◽  
Extensive Literature ◽  
Ang Ii ◽  
Mas Receptor ◽  
The Central Nervous System ◽  
The Brain

Background: The Renin-Angiotensin System (RAS) is a key regulator of cardiovascular and renal homeostasis, but also plays important roles in mediating physiological functions in the central nervous system (CNS). The effects of the RAS were classically described as mediated by angiotensin (Ang) II via angiotensin type 1 (AT1) receptors. However, another arm of the RAS formed by the angiotensin converting enzyme 2 (ACE2), Ang-(1-7) and the Mas receptor has been a matter of investigation due to its important physiological roles, usually counterbalancing the classical effects exerted by Ang II. Objective: We aim to provide an overview of effects elicited by the RAS, especially Ang-(1-7), in the brain. We also aim to discuss the therapeutic potential for neuropsychiatric disorders for the modulation of RAS. Method: We carried out an extensive literature search in PubMed central. Results: Within the brain, Ang-(1-7) contributes to the regulation of blood pressure by acting at regions that control cardiovascular functions. In contrast with Ang II, Ang-(1-7) improves baroreflex sensitivity and plays an inhibitory role in hypothalamic noradrenergic neurotransmission. Ang-(1-7) not only exerts effects related to blood pressure regulation, but also acts as a neuroprotective component of the RAS, for instance, by reducing cerebral infarct size, inflammation, oxidative stress and neuronal apoptosis. Conclusion: Pre-clinical evidence supports a relevant role for ACE2/Ang-(1-7)/Mas receptor axis in several neuropsychiatric conditions, including stress-related and mood disorders, cerebrovascular ischemic and hemorrhagic lesions and neurodegenerative diseases. However, very few data are available regarding the ACE2/Ang-(1-7)/Mas receptor axis in human CNS.

Сellular and Molecular Mechanisms of Proinflammatory Monocytes Participation in the Pathogenesis of Mental Disorders. Part 3

Psychiatry ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 125-134
Author(s):  
E. F. Vasilyeva ◽  
O. S. Brusov
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Mental Disorders ◽  
Molecular Mechanisms ◽  
Microglial Cells ◽  
Inflammatory Reactions ◽  
Mental Diseases ◽  
The Central Nervous System ◽  
The Brain

Background: at present, the important role of the monocyte-macrophage link of immunity in the pathogenesis of mental diseases has been determined. In the first and second parts of our review, the cellular and molecular mechanisms of activation of monocytes/macrophages, which secreting proinflammatory CD16 receptors, cytokines, chemokines and receptors to them, in the development of systemic immune inflammation in the pathogenesis of somatic diseases and mental disorders, including schizophrenia, bipolar affective disorder (BAD) and depression were analyzed. The association of high levels of proinflammatory activity of monocytes/macrophages in patients with mental disorders with somatic comorbidity, including immune system diseases, is shown. It is known that proinflammatory monocytes of peripheral blood, as a result of violation of the integrity of the hematoencephalic barrier can migrate to the central nervous system and activate the resident brain cells — microglia, causing its activation. Activation of microglia can lead to the development of neuroinammation and neurodegenerative processes in the brain and, as a result, to cognitive disorders. The aim of review: to analyze the results of the main scientific studies concerning the role of cellular and molecular mechanisms of peripheral blood monocytes interaction with microglial cells and platelets in the development of neuroinflammation in the pathogenesis of mental disorders, including Alzheimer’s disease (AD). Material and methods: keywords “mental disorders, AD, proinflammatory monocytes, microglia, neuroinflammation, cytokines, chemokines, cell adhesion molecules, platelets, microvesicles” were used to search for articles of domestic and foreign authors published over the past 30 years in the databases PubMed, eLibrary, Science Direct and EMBASE. Conclusion: this review analyzes the results of studies which show that monocytes/macrophages and microglia have similar gene expression profiles in schizophrenia, BAD, depression, and AD and also perform similar functions: phagocytosis and inflammatory responses. Monocytes recruited to the central nervous system stimulate the increased production of proinflammatory cytokines IL-1, IL-6, tumor necrosis factor alpha (TNF-α), chemokines, for example, MCP-1 (Monocyte chemotactic protein-1) by microglial cells. This promotes the recruitment of microglial cells to the sites of neuronal damage, and also enhances the formation of the brain protein beta-amyloid (Aβ). The results of modern studies are presented, indicating that platelets are involved in systemic inflammatory reactions, where they interact with monocytes to form monocyte-platelet aggregates (MTA), which induce the activation of monocytes with a pro inflammatory phenotype. In the last decade, it has been established that activated platelets and other cells of the immune system, including monocytes, detached microvesicles (MV) from the membrane. It has been shown that MV are involved as messengers in the transport of biologically active lipids, cytokines, complement, and other molecules that can cause exacerbation of systemic inflammatory reactions. The presented review allows us to expand our knowledge about the cellular and molecular aspects of the interaction of monocytes/macrophages with microglial cells and platelets in the development of neuroinflammation and cognitive decline in the pathogenesis of mental diseases and in AD, and also helps in the search for specific biomarkers of the clinical severity of mental disorder in patients and the prospects for their response to treatment.

scholarly journals Effect of Luteolin and Apigenin on the Production of Il-31 and Il-33 in Lipopolysaccharides-Activated Microglia Cells and Their Mechanism of Action

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 811 ◽  
Author(s):  
Denis Nchang Che ◽  
Byoung Ok Cho ◽  
Ji-su Kim ◽  
Jae Young Shin ◽  
Hyun Ju Kang ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neurodegenerative Diseases ◽  
Signaling Pathways ◽  
Nuclear Translocation ◽  
Mapk Pathway ◽  
Microglial Cells ◽  
Stat3 Signaling ◽  
Protein Expressions ◽  
The Central Nervous System

Microglia cells are resident cells of the central nervous system (CNS) charged with modulating inflammation in the CNS. Overstimulation of microglia cells continuously releases inflammatory mediators that contribute to neurodegenerative diseases. Apigenin and Luteolin are flavonoids with reported anti-inflammatory activities. However, their effects on IL-31 and IL-33 production in microglial cells are unknown. Here, we investigated the effects of apigenin and luteolin on the production of IL-31 and IL-33 by microglia cells. SIM-A9 microglial cells were pre-treated with apigenin or luteolin and stimulated with lipopolysaccharides to evaluate the production of IL-31 and IL-33. The study revealed that apigenin and luteolin inhibited the production of IL-31 and IL-33 at the gene and protein expressions and the secretion levels. Using potent inhibitors of MAPK, NF-κB, and STAT3 signaling pathways, we demonstrated that apigenin and luteolin’s suppression of ERK and JNK contributed to the inhibition of IL-31 and IL-33 in the MAPK pathway. Luteolin’s suppression of NF-κB and STAT3 also contributed to the inhibition of IL-31 and IL-33. Further analysis revealed that both compounds prevented nuclear translocation of activated NF-κB and STAT3, an act that subsequently prevented their DNA binding activities. Collectively, the study suggested that apigenin and luteolin’s regulation of signaling pathways contributed to the inhibition of IL-31 and IL-33, thus suggesting its importance for the improvement of neurodegenerative diseases involving these two cytokines.

scholarly journals Aging enhances classical activation but mitigates alternative activation in the central nervous system

2013 ◽  
Vol 34 (6) ◽  
pp. 1610-1620 ◽  
Author(s):  
Daniel C. Lee ◽  
Claudia R. Ruiz ◽  
Lori Lebson ◽  
Maj-Linda B. Selenica ◽  
Justin Rizer ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Alternative Activation ◽  
Classical Activation ◽  
The Central Nervous System

Role of the glucose-dependent insulinotropic polypeptide and its receptor in the central nervous system: therapeutic potential in neurological diseases

2010 ◽  
Vol 21 (5-6) ◽  
pp. 394-408 ◽  
Author(s):  
Cláudia P. Figueiredo ◽  
Fabrício A. Pamplona ◽  
Tânia L. Mazzuco ◽  
Aderbal S. Aguiar ◽  
Roger Walz ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Therapeutic Potential ◽  
Neurological Diseases ◽  
The Central Nervous System

scholarly journals Physiology of Microglia

2011 ◽  
Vol 91 (2) ◽  
pp. 461-553 ◽  
Author(s):  
Helmut Kettenmann ◽  
Uwe-Karsten Hanisch ◽  
Mami Noda ◽  
Alexei Verkhratsky
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Immune Cell ◽  
Brain Parenchyma ◽  
Microglial Cells ◽  
Activation Process ◽  
Normal Brain ◽  
The Central Nervous System ◽  
Cellular Compartments ◽  
The Brain

Microglial cells are the resident macrophages in the central nervous system. These cells of mesodermal/mesenchymal origin migrate into all regions of the central nervous system, disseminate through the brain parenchyma, and acquire a specific ramified morphological phenotype termed “resting microglia.” Recent studies indicate that even in the normal brain, microglia have highly motile processes by which they scan their territorial domains. By a large number of signaling pathways they can communicate with macroglial cells and neurons and with cells of the immune system. Likewise, microglial cells express receptors classically described for brain-specific communication such as neurotransmitter receptors and those first discovered as immune cell-specific such as for cytokines. Microglial cells are considered the most susceptible sensors of brain pathology. Upon any detection of signs for brain lesions or nervous system dysfunction, microglial cells undergo a complex, multistage activation process that converts them into the “activated microglial cell.” This cell form has the capacity to release a large number of substances that can act detrimental or beneficial for the surrounding cells. Activated microglial cells can migrate to the site of injury, proliferate, and phagocytose cells and cellular compartments.

scholarly journals Activation and Regulation of Cellular Inflammasomes: Gaps in Our Knowledge for Central Nervous System Injury

2014 ◽  
Vol 34 (3) ◽  
pp. 369-375 ◽  
Author(s):  
Juan Pablo de Rivero Vaccari ◽  
W Dalton Dietrich ◽  
Robert W Keane
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Therapeutic Potential ◽  
Interleukin 1 ◽  
Cns Injury ◽  
Cord Injury ◽  
Cns Trauma ◽  
The Central Nervous System ◽  
Brain And Spinal Cord

The inflammasome is an intracellular multiprotein complex involved in the activation of caspase-1 and the processing of the proinflammatory cytokines interleukin-1 β (IL-1 β) and IL-18. The inflammasome in the central nervous system (CNS) is involved in the generation of an innate immune inflammatory response through IL-1 cytokine release and in cell death through the process of pyroptosis. In this review, we consider the different types of inflammasomes (NLRP1, NLRP2, NLRP3, and AIM2) that have been described in CNS cells, namely neurons, astrocytes, and microglia. Importantly, we focus on the role of the inflammasome after brain and spinal cord injury and cover the potential activators of the inflammasome after CNS injury such as adenosine triphosphate and DNA, and the therapeutic potential of targeting the inflammasome to improve outcomes after CNS trauma.

FTY720 on the way from the base camp to the summit of the mountain: relevance for remyelination

2012 ◽  
Vol 18 (3) ◽  
pp. 258-263 ◽  
Author(s):  
M Kipp ◽  
S Amor
Keyword(s):  
Multiple Sclerosis ◽  
Central Nervous System ◽  
Nervous System ◽  
Therapeutic Potential ◽  
Oral Disease ◽  
S1p Receptors ◽  
Receptor Modulator ◽  
Sphingosine 1 Phosphate ◽  
The Central Nervous System

FTY720 (fingolimod; Gilenya®), a sphingosine 1-phosphate (S1P) receptor modulator, is the first oral disease-modifying therapy to be approved for the treatment of relapsing–remitting multiple sclerosis. FTY720 is rapidly converted in vivo to the active S-fingolimod-phosphate, which binds to S1P receptors. This action inhibits egress of lymphocytes from the lymph nodes, preventing entry into the blood and thus infiltration into the central nervous system. More recent studies, however, convincingly show that FTY720 crosses the blood–brain barrier, where it is thought to act on S1P receptors on cells within the central nervous system, such as astrocytes, oligodendrocytes or microglia. Here we discuss the evidence showing that FTY720 also plays a role in remyelination and repair within the brain. While the mechanisms of action still require firm elucidation, it is clear that FTY720 could also be reparative, extending its therapeutic potential for multiple sclerosis.

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