scholarly journals Neutrophils Return to Bloodstream Through the Brain Blood Vessel After Crosstalk With Microglia During LPS-Induced Neuroinflammation

2020 ◽  
Vol 8 ◽  
Author(s):  
Yu Rim Kim ◽  
Young Min Kim ◽  
Jaeho Lee ◽  
Joohyun Park ◽  
Jong Eun Lee ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Molecular Mechanisms ◽  
Morphological Changes ◽  
Neutrophil Infiltration ◽  
Two Photon ◽  
Activated State ◽  
The Central Nervous System ◽  
Time Observation ◽  
And Function ◽  
The Brain

The circulatory neutrophil and brain tissue-resident microglia are two important immune cells involved in neuroinflammation. Since neutrophils that infiltrate through the brain vascular vessel may affect the immune function of microglia in the brain, close investigation of the interaction between these cells is important in understanding neuroinflammatory phenomena and immunological aftermaths that follow. This study aimed to observe how morphology and function of both neutrophils and microglia are converted in the inflamed brain. To directly investigate cellular responses of neutrophils and microglia, LysMGFP/+ and CX3CR1GFP/+ mice were used for the observation of neutrophils and microglia, respectively. In addition, low-dose lipopolysaccharide (LPS) was utilized to induce acute inflammation in the central nervous system (CNS) of mice. Real-time observation on mice brain undergoing neuroinflammation via two-photon intravital microscopy revealed various changes in neutrophils and microglia; namely, neutrophil infiltration and movement within the brain tissue increased, while microglia displayed morphological changes suggesting an activated state. Furthermore, neutrophils seemed to not only actively interact with microglial processes but also exhibit reverse transendothelial migration (rTEM) back to the bloodstream. Thus, it may be postulated that, through crosstalk with neutrophils, macrophages are primed to initiate a neuroinflammatory immune response; also, during pathogenic events in the brain, neutrophils that engage in rTEM may deliver proinflammatory signals to peripheral organs outside the brain. Taken together, these results both show that neuroinflammation results in significant alterations in neutrophils and microglia and lay the pavement for further studies on the molecular mechanisms behind such changes.

scholarly journals Glymphatic System in the Central Nervous System, a Novel Therapeutic Direction Against Brain Edema After Stroke

2021 ◽  
Vol 13 ◽  
Author(s):  
Xiangyue Zhou ◽  
Youwei Li ◽  
Cameron Lenahan ◽  
Yibo Ou ◽  
Minghuan Wang ◽  
...  
Keyword(s):  
Brain Edema ◽  
Brain Tissue ◽  
Molecular Mechanisms ◽  
Glymphatic System ◽  
System A ◽  
Function Recovery ◽  
The Central Nervous System ◽  
The Stability ◽  
The Brain

Stroke is the destruction of brain function and structure, and is caused by either cerebrovascular obstruction or rupture. It is a disease associated with high mortality and disability worldwide. Brain edema after stroke is an important factor affecting neurologic function recovery. The glymphatic system is a recently discovered cerebrospinal fluid (CSF) transport system. Through the perivascular space and aquaporin 4 (AQP4) on astrocytes, it promotes the exchange of CSF and interstitial fluid (ISF), clears brain metabolic waste, and maintains the stability of the internal environment within the brain. Excessive accumulation of fluid in the brain tissue causes cerebral edema, but the glymphatic system plays an important role in the process of both intake and removal of fluid within the brain. The changes in the glymphatic system after stroke may be an important contributor to brain edema. Understanding and targeting the molecular mechanisms and the role of the glymphatic system in the formation and regression of brain edema after stroke could promote the exclusion of fluids in the brain tissue and promote the recovery of neurological function in stroke patients. In this review, we will discuss the physiology of the glymphatic system, as well as the related mechanisms and therapeutic targets involved in the formation of brain edema after stroke, which could provide a new direction for research against brain edema after stroke.

scholarly journals Expression of NMDA receptor and microRNA-219 in rats submitted to cerebral ischemia associated with alcoholism

2017 ◽  
Vol 75 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Cristiane Iozzi Silva ◽  
Paulo Cézar Novais ◽  
Andressa Romualdo Rodrigues ◽  
Camila A.M. Carvalho ◽  
Benedicto Oscar Colli ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cerebral Ischemia ◽  
Brain Tissue ◽  
Wistar Rats ◽  
Molecular Mechanisms ◽  
Inverse Correlation ◽  
Control Group ◽  
The Brain ◽  
Lower Expression ◽  
Control Sham

ABSTRACT Alcohol consumption aggravates injuries caused by ischemia. Many molecular mechanisms are involved in the pathophysiology of cerebral ischemia, including neurotransmitter expression, which is regulated by microRNAs. Objective: To evaluate the microRNA-219 and NMDA expression in brain tissue and blood of animals subjected to cerebral ischemia associated with alcoholism. Methods: Fifty Wistar rats were divided into groups: control, sham, ischemic, alcoholic, and ischemic plus alcoholic. The expression of microRNA-219 and NMDA were analyzed by real-time PCR. Results: When compared to the control group, the microRNA-219 in brain tissue was less expressed in the ischemic, alcoholic, and ischemic plus alcoholic groups. In the blood, this microRNA had lower expression in alcoholic and ischemic plus alcoholic groups. In the brain tissue the NMDA gene expression was greater in the ischemic, alcoholic, and ischemic plus alcoholic groups. Conclusion: A possible modulation of NMDA by microRNA-219 was observed with an inverse correlation between them.

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.

The neutrophil enzyme myeloperoxidase directly modulates neuronal response after subarachnoid hemorrhage, a sterile injury model

2020 ◽  
Author(s):  
Aminata P. Coulibaly ◽  
Pinar Pezuk ◽  
Paul Varghese ◽  
William Gartman ◽  
Danielle Triebwasser ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Cognitive Deficits ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Neuronal Response ◽  
Neutrophil Infiltration ◽  
Brain Parenchyma ◽  
Biologically Active ◽  
Cns Injury ◽  
And Function ◽  
The Brain

Abstract Background: Aneurysmal subarachnoid hemorrhage (SAH) is associated with the development of delayed cognitive deficits. Neutrophil infiltration into the central nervous system (CNS) is linked to the development of these deficits after SAH. It is however unclear how neutrophil activity, direct or indirect, influences CNS function in SAH. As such, the present project aims to elucidate neutrophil factors and mechanisms mediating CNS injury and cognitive deficits after SAH. Methods: Using a murine model of SAH and mice deficient in neutrophil effector functions, we determined which neutrophil effector function is critical to the development of deficits after SAH. Also, in vitro techniques were used to elucidate whether neutrophils directly or indirectly affect neuronal function after SAH. Results: Our results show that following SAH, neutrophils infiltrate the meninges, and not the brain parenchyma. Mice lacking functional myeloperoxidase (MPO KO), a neutrophil enzyme, lack both the meningeal neutrophil infiltration and the cognitive deficits associated with SAH. The re-introduction of biologically active MPO, and its substrate hydrogen peroxide, to the cerebrospinal fluid of MPO KO mice at the time of hemorrhage restores the spatial memory deficit observed after SAH. Furthermore, MPO directly affects the function of both primary neurons and astrocytes in culture. Neurons exposed to MPO and its substrate show decreased calcium activity at baseline and after stimulation with potassium chloride. In addition, MPO and its substrate lead to significant astrocyte loss in culture, phenocopying a result observed in the brain after SAH. Conclusions: These results implicate MPO as a mediator of neuronal dysfunction in SAH through direct effect on both neurons and astrocytes. Finally, these results show that, in SAH, the activity of innate immune cells in the meninges can modulate the activity and function of the underlying brain tissue.

Ventricular and Cerebrospinal Fluid System

2017 ◽  
pp. 409-434
Author(s):  
Eduardo E. Benarroch ◽  
Jeremy K. Cutsforth-Gregory ◽  
Kelly D. Flemming
Keyword(s):  
Cerebrospinal Fluid ◽  
Neural Tissue ◽  
Local Environment ◽  
System P ◽  
Neurologic Disorders ◽  
Unique System ◽  
The Central Nervous System ◽  
Protective Structures ◽  
And Function ◽  
The Brain

The meninges, ventricular system, subarachnoid space, and cerebrospinal fluid (CSF) constitute a functionally unique system that has an important role in maintaining a stable environment within which the central nervous system can function. The membranes that constitute the meninges serve as supportive and protective structures for neural tissue. The CSF itself provides a cushioning effect during rapid movement of the head and mechanical buoyancy to the brain. In addition to providing a pathway for the removal of brain metabolites, it functions as a chemical reservoir that protects the local environment of the brain from changes that may occur in the blood, thus ensuring the brain’s continued undisturbed performance. The CSF system is present at the supratentorial, posterior fossa, and spinal levels. Because of this extensive anatomical distribution and function, pathologic alterations of the CSF system can occur in many neurologic disorders.

scholarly journals The Role of Adrenoceptors in the Retina

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2594
Author(s):  
Yue Ruan ◽  
Tobias Böhmer ◽  
Subao Jiang ◽  
Adrian Gericke
Keyword(s):  
Visual Information ◽  
Vision Loss ◽  
Retinal Diseases ◽  
System A ◽  
The Central Nervous System ◽  
The Individual ◽  
And Function ◽  
The Brain

The retina is a part of the central nervous system, a thin multilayer with neuronal lamination, responsible for detecting, preprocessing, and sending visual information to the brain. Many retinal diseases are characterized by hemodynamic perturbations and neurodegeneration leading to vision loss and reduced quality of life. Since catecholamines and respective bindings sites have been characterized in the retina, we systematically reviewed the literature with regard to retinal expression, distribution and function of alpha1 (α1)-, alpha2 (α2)-, and beta (β)-adrenoceptors (ARs). Moreover, we discuss the role of the individual adrenoceptors as targets for the treatment of retinal diseases.

scholarly journals A sart1 Zebrafish Mutant Results in Developmental Defects in the Central Nervous System

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2340
Author(s):  
Hannah E. Henson ◽  
Michael R. Taylor
Keyword(s):  
Central Nervous System ◽  
Cell Death ◽  
Nervous System ◽  
Developmental Defects ◽  
Whole Exome ◽  
The Central Nervous System ◽  
And Function ◽  
Upregulated Genes ◽  
The Brain

The spliceosome consists of accessory proteins and small nuclear ribonucleoproteins (snRNPs) that remove introns from RNA. As splicing defects are associated with degenerative conditions, a better understanding of spliceosome formation and function is essential. We provide insight into the role of a spliceosome protein U4/U6.U5 tri-snRNP-associated protein 1, or Squamous cell carcinoma antigen recognized by T-cells (Sart1). Sart1 recruits the U4.U6/U5 tri-snRNP complex to nuclear RNA. The complex then associates with U1 and U2 snRNPs to form the spliceosome. A forward genetic screen identifying defects in choroid plexus development and whole-exome sequencing (WES) identified a point mutation in exon 12 of sart1 in Danio rerio (zebrafish). This mutation caused an up-regulation of sart1. Using RNA-Seq analysis, we identified additional upregulated genes, including those involved in apoptosis. We also observed increased activated caspase 3 in the brain and eye and down-regulation of vision-related genes. Although splicing occurs in numerous cells types, sart1 expression in zebrafish was restricted to the brain. By identifying sart1 expression in the brain and cell death within the central nervous system (CNS), we provide additional insights into the role of sart1 in specific tissues. We also characterized sart1’s involvement in cell death and vision-related pathways.

scholarly journals GBE50 Attenuates Inflammatory Response by Inhibiting the p38 MAPK and NF-κB Pathways in LPS-Stimulated Microglial Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Gai-ying He ◽  
Chong-gang Yuan ◽  
Li Hao ◽  
Ying Xu ◽  
Zhi-xiong Zhang
Keyword(s):  
Signal Transduction ◽  
P38 Mapk ◽  
Molecular Mechanisms ◽  
Morphological Changes ◽  
Interleukin 1 ◽  
Bv2 Cells ◽  
Proinflammatory Responses ◽  
Bv2 Microglia ◽  
The Central Nervous System ◽  
Anti Inflammatory

Overactivated microglia contribute to a variety of pathological conditions in the central nervous system. The major goal of the present study is to evaluate the potential suppressing effects of a new type of Ginko biloba extract, GBE50, on activated microglia which causes proinflammatory responses and to explore the underlying molecular mechanisms. Murine BV2 microglia cells, with or without pretreatmentof GBE50 at various concentrations, were activated by incubation with lipopolysaccharide (LPS). A series of biochemical and microscopic assays were performed to measure cell viability, cell morphology, release of tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β), and signal transduction via the p38 MAPK and nuclear factor-kappa B (NF-κB) p65 pathways. We found that GBE50 pretreatment suppressed LPS-induced morphological changes in BV2 cells. Moreover, GBE50 treatment significantly reduced the release of proinflammatory cytokines, TNF-αand IL-1β, and inhibited the associated signal transduction through the p38 MAPK and NF-κB p65 pathways. These results demonstrated the anti-inflammatory effect of GBE50 on LPS-activated BV2 microglia cells, and indicated that GBE50 reduced the LPS-induced proinflammatory TNF-αand IL-1βrelease by inhibiting signal transduction through the NF-κB p65 and p38 MAPK pathways. Our findings reveal, at least in part, the molecular basis underlying the anti-inflammatory effects of GBE50.

Morphological changes in the brain of wistar rats after insulin injection

2015 ◽  
Vol 9 (1) ◽  
pp. 0-0 ◽  
Author(s):  
Бантыш ◽  
B. Bantysh ◽  
Макишева ◽  
R. Makisheva ◽  
Субботина ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Brain Tissue ◽  
Cortical Neurons ◽  
Wistar Rats ◽  
Morphological Changes ◽  
Thrombus Formation ◽  
Visual Fields ◽  
Insulin Injection ◽  
Old Rats ◽  
The Brain

The morphological changes in the brain tissue of Wistar rats of different ages after intramuscular insulin injection in the dose of 1 IU/kg are typical for the hypoxic lesions of nervous tissue. The brain of rats at the age of 1-2 months responds to increased deposition of glycogen, moderate swelling around the cells and blood vessels. The effect of insulin on the brain Mature rats at the age of 5-7 months leads to vasodilatation, more pronounced swelling around the cells and blood vessels, hypertrophy of cells, aggregation and diabetes of red blood cells. The severity of ischemic changes significantly increased in the brain of old rats at the age of 20-24 months. These old rats had the senile dendrites, the widespread hypertrophic degenerative changes, i.e. flask-shaped vasodilation, hyperemia. In most of the visual fields are detected capillaries with the presence of aggregation on the side erythrocytes, signs of micro thrombosis, hemorrhage areas. The authors note that there is a loss of tone and tortuosity of the small arterioles, widespread swelling around the cells and around the blood vessels. Morphological signs of brain reaction on insulin injection reflect the death of cortical neurons, marked swelling of the brain tissue, disruption of vascular permeability, the thrombus formation and hemorrhages.

scholarly journals Altered central TRPV4 expression and lipid raft association related to inappropriate vasopressin secretion in cirrhotic rats

2009 ◽  
Vol 296 (2) ◽  
pp. R454-R466 ◽  
Author(s):  
Flávia Regina Carreño ◽  
Lisa L. Ji ◽  
J. Thomas Cunningham
Keyword(s):  
Lipid Raft ◽  
Supraoptic Nucleus ◽  
Molecular Mechanisms ◽  
Bile Duct Ligation ◽  
Plasma Osmolality ◽  
Plasma Renin ◽  
Duct Ligation ◽  
The Central Nervous System ◽  
Vasopressin Secretion ◽  
The Brain

Inappropriate vasopressin (AVP) release causes dilutional hyponatremia in many pathophysiological states such as cirrhosis. The central molecular mechanisms that mediate inappropriate AVP release are unknown. We tested the hypothesis that changes in the expression or trafficking of TRPV4 in the central nervous system may contribute to inappropriate AVP release in the bile duct ligation (BDL) model of cirrhosis in the rat. Four weeks after surgery, BDL rats demonstrated significantly increased plasma vasopressin and plasma renin activity (PRA), hypervolemia, and decreased plasma osmolality. These effects were blocked by providing BDL rats with 2% saline to drink for 15 days. TRPV4 protein expression was significantly increased in brain punches from BDL rats containing the supraoptic nucleus (SON) of the hypothalamus (100% ± 11 to 157% ± 4.8), and this effect was blocked in BDL rats given saline. Immunohistochemistry demonstrated a significant increase in TRPV4-positive cells and the percentage of AVP neurons that also were TRPV4-positive in the SON of BDL rats. In the hypothalamus of BDL rats, TRPV4 lipid raft association increased compared with sham (from 100% ± 2.1 to 326.1% ± 16). This effect was significantly attenuated in BDL rats given 2% saline to drink (174% ± 11). In the brain stem, TRPV4 lipid raft association was reduced by BDL and inversely related to plasma AVP and PRA. We speculate that changes in TRPV4 expression and compartmentalization within lipid rafts could contribute to a feed-forward mechanism related to AVP release in cirrhosis.

Sign in / Sign up

Export Citation Format

Share Document