scholarly journals Regional difference in inflammatory response to LPS-injection in the brain: Role of microglia cell density

2011 ◽  
Vol 238 (1-2) ◽  
pp. 44-51 ◽  
Author(s):  
Cristina Pintado ◽  
Elisa Revilla ◽  
María L. Vizuete ◽  
Sebastián Jiménez ◽  
Luisa García-Cuervo ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Cell Density ◽  
Regional Difference ◽  
Microglia Cell ◽  
The Brain

scholarly journals MicroRNA-210 downregulates TET2 and contributes to inflammatory response in neonatal hypoxic-ischemic brain injury

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Qingyi Ma ◽  
Chiranjib Dasgupta ◽  
Guofang Shen ◽  
Yong Li ◽  
Lubo Zhang
Keyword(s):  
Brain Injury ◽  
Inflammatory Response ◽  
Protein Level ◽  
Inflammatory Cytokine ◽  
Neuroprotective Effect ◽  
Neonatal Brain ◽  
Brain Infarct ◽  
Microglia Cell ◽  
The Brain

Abstract Background Neonatal hypoxic-ischemic (HI) brain injury is a leading cause of acute mortality and chronic disability in newborns. Our previous studies demonstrated that HI insult significantly increased microRNA-210 (miR-210) in the brain of rat pups and inhibition of brain endogenous miR-210 by its inhibitor (LNA) provided neuroprotective effect in HI-induced brain injury. However, the molecular mechanisms underpinning this neuroprotection remain unclear. Methods We made a neonatal HI brain injury model in mouse pups of postnatal day 7 to uncover the mechanism of miR-210 in targeting the ten eleven translocation (TET) methylcytosine dioxygenase 2 that is a transcriptional suppressor of pro-inflammatory cytokine genes in the neonatal brain. TET2 silencing RNA was used to evaluate the role of TET2 in the neonatal HI-induced pro-inflammatory response and brain injury. MiR-210 mimic and inhibitor (LNA) were delivered into the brain of mouse pups to study the regulation of miR-210 on the expression of TET2. Luciferase reporter gene assay was performed to validate the direct binding of miR-210 to the 3′ untranslated region of the TET2 transcript. Furthermore, BV2 mouse microglia cell line was employed to confirm the role of miR-210-TET2 axis in regulating pro-inflammatory response in microglia. Post-assays included chromatin immunoprecipitation (ChIP) assay, co-immunoprecipitation, RT-PCR, brain infarct assay, and neurobehavioral test. Student’s t test or one-way ANOVA was used for statistical analysis. Results HI insult significantly upregulated miR-210, downregulated TET2 protein abundance, and increased NF-κB subunit p65 acetylation level and its DNA binding capacity to the interleukin 1 beta (IL-1β) promoter in the brain of mouse pups. Inhibition of miR-210 rescued TET2 protein level from HI insult and miR-210 mimic decreased TET2 protein level in the brain of mouse pups, suggesting that TET2 is a functional target of miR-210. The co-immunoprecipitation was performed to reveal the role of TET2 in HI-induced inflammatory response in the neonatal brain. The result showed that TET2 interacted with NF-κB subunit p65 and histone deacetylase 3 (HDAC3), a co-repressor of gene transcription. Furthermore, TET2 knockdown increased transcriptional activity of acetyl-p65 on IL-1β gene in the neonatal brain and enhanced HI-induced upregulation of acetyl-p65 level and pro-inflammatory cytokine expression. Of importance, TET2 knockdown exacerbated brain infarct size and neurological deficits and counteracted the neuroprotective effect of miR-210 inhibition. Finally, the in vitro results demonstrated that the miR-210-TET2 axis regulated pro-inflammatory response in BV2 mouse microglia cell line. Conclusions The miR-210-TET2 axis regulates pro-inflammatory cytokine expression in microglia, contributing to neonatal HI brain injury.

Integrative view of serpins in health and disease: the contribution of serpinA3

2020 ◽  
Author(s):  
Andrea Sanchez-Navarro ◽  
Isaac González-Soria ◽  
Rebecca Caldiño-Bohn ◽  
Norma A. Bobadilla
Keyword(s):  
Oxidative Stress ◽  
Inflammatory Response ◽  
Cellular Processes ◽  
Hormone Transport ◽  
Integrative View ◽  
Health And Disease ◽  
The Brain ◽  
Regulation Of Blood Pressure ◽  
Common Function

Serpins are a superfamily of proteins characterized by their common function as serine protease inhibitors. So far, 36 serpins from nine clades have been identified. These proteins are expressed in all the organs and are involved in multiple important functions such as the regulation of blood pressure, hormone transport, insulin sensitivity, and the inflammatory response. Diseases such as obesity, diabetes, cardiovascular, and kidney disorders are intensively studied to find effective therapeutic targets. Given serpins' outstanding functionality, the deficiency or overexpression of certain types of serpin have been associated with diverse pathophysiological events. In particular, we will focus on reviewing the studies evaluating the participation of serpins, and particularly SerpinA3, in diverse diseases that occur in relevant organs such as the brain, retinas, corneas, lungs, cardiac vasculature, and kidneys. In this review, we summarize the role of serpins in physiological and pathophysiological processes, as well as recent evidence on the crucial role of SerpinA3 in several pathologies. Finally, we emphasize the importance of SerpinA3 in regulating cellular processes such as angiogenesis, apoptosis, fibrosis, oxidative stress, and the inflammatory response.

scholarly journals Microglial phagocytosis dysfunction during stroke is prevented by rapamycin

2021 ◽  
Author(s):  
Sol Beccari ◽  
Virginia Sierra-Torre ◽  
Jorge Valero ◽  
Mikel Garcia-Zaballa ◽  
Alejandro Carretero-Guillen ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Therapeutic Target ◽  
Apoptotic Cell ◽  
Knock Out ◽  
Microglial Phagocytosis ◽  
Cellular Debris ◽  
The Brain

Microglial phagocytosis is rapidly emerging as a therapeutic target in neurodegenerative and neurological disorders. An efficient removal of cellular debris is necessary to prevent buildup damage of neighbor neurons and the development of an inflammatory response. As the brain professional phagocytes, microglia are equipped with an array of mechanisms that enable them to recognize and degrade several types of cargo, including neurons undergoing apoptotic cell death. While microglia are very competent phagocytes of apoptotic cells under physiological conditions, here we report their dysfunction in mouse and monkey (Macaca fascicularis and Callithrix jacchus) models of stroke by transient occlusion of the medial cerebral artery (tMCAo). The impairment of both engulfment and degradation was related to energy depletion triggered by oxygen and nutrients deprivation (OND), which led to reduced process motility, lysosomal depletion, and the induction of a protective autophagy response in microglia. Basal autophagy, which is in charge of removing and recycling intracellular elements, was critical to maintain microglial physiology, including survival and phagocytosis, as we determined both in vivo and in vitro using knock-out models of autophagy genes and the autophagy inhibitor MRT68921. Notably, the autophagy inducer rapamycin partially prevented the phagocytosis impairment induced by tMCAo in vivo but not by OND in vitro. These results suggest a more complex role of microglia in stroke than previously acknowledged, classically related to the inflammatory response. In contrast, here we demonstrate the impairment of apoptotic cell phagocytosis, a microglial function critical for brain recovery. We propose that phagocytosis is a therapeutic target yet to be explored and provide evidence that it can be modulated in vivo using rapamycin, setting the stage for future therapies for stroke patients.

scholarly journals Inflammatory mechanisms of mental illness: brain inflammatory response to interferon stimulation

BJPsych Open ◽  
2021 ◽  
Vol 7 (S1) ◽  
pp. S256-S256
Author(s):  
James Herron ◽  
Jonathan Cavanagh
Keyword(s):  
Inflammatory Response ◽  
Inflammatory Cytokines ◽  
Quantitative Polymerase Chain Reaction ◽  
Statistical Significance ◽  
Significant Risk ◽  
Sickness Behaviour ◽  
Immune Mechanisms ◽  
Cytokines And Chemokines ◽  
The Brain

AimsWe hypothesise that peripheral IFN stimulation results in a brain inflammatory response via pathways of neuroimmune communication which in turn results in sickness-behaviour and depressive phenotype. We aim to determine if peripheral IFN stimulation results in brain inflammatory response including upregulation of inflammatory cytokines and chemokines.BackgroundThere is increasing interest in the role of dysregulated immune function and inflammation in the pathogenesis of psychiatric disorders including mood disorders and dementias. Immune mechanisms offer a new approach to investigating mechanism in addition to offering hope for new avenues of treatment.Interferon (IFN) therapy in humans is known to be associated with a significant risk of developing depression, both during therapy and increasing risk of relapse in the years following exposure, yet the mechanism remains unclear. IFN stimulation in animal models may offer insights into this phenomenon, in addition to furthering our understanding the role of immune mechanisms in the development of psychiatric phenotypes.MethodMice (n. 42) were exposed to either IFN-alpha, IFN-gamma or vehicle control using either osmotic pump or intraperitoneal injection over the course of 7 days. Mice were scarificed, brains were dissected and RNA extracted. Inflammatory gene transcription within the brain was determined using real time quantitative polymerase chain reaction (RTqPCR). Absolute quantification was achieved using standard curves and reference gene. Statistical significance was determined using Mann-Whitney or ANOVA/Kruskal-Wallis depending on normality of data and number of groups.ResultIFNγ stimulation is associated with a significant brain upregulation of a number of inflammatory cytokines and chemokines including Il1β, Tnfα, Il10, Ifnγ, Ccl2, Ccl5, Ccl19, Cxcl10 and Ccr5. However, unexpectedly we did not find IFNα stimulation to associate with brain inflammatory transcriptional changes.ConclusionThis work demonstrates a brain inflammatory response to peripheral IFNγ stimulation. The inflammatory profile, including upregulated chemokines, suggests that recruitment of leukocytes across the blood brain barrier may be part of the immune response. Further experiments using existing tissues will explore if there are structural/cellular changes within the brain parenchyma. Further experiments within the group will seek to demonstrate if IFN treatment associates with sickness behaviour in order to determine if this is a clinically meaningful model. Suprisingly, we did not see similar changes in the IFNα treated group, which requires further investigation.Funding: University of Glasgow, The Sackler Trust

scholarly journals The 5-HT3 receptor affects rotavirus-induced motility

2021 ◽  
Author(s):  
Marie Hagbom ◽  
Arash Hellysaz ◽  
Claudia Istrate ◽  
Johan Nordgren ◽  
Sumit Sharma ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Vagus Nerve ◽  
Intestinal Motility ◽  
Serotonin Receptor ◽  
Early Gene ◽  
Rotavirus Infection ◽  
Significant Difference ◽  
Electrolyte Secretion ◽  
The Brain

Rotavirus infection is highly prevalent in children, and the most severe effects are diarrhea and vomiting. It is well accepted that the enteric nervous system (ENS) is activated and plays an important role, but knowledge of how rotavirus activates nerves within ENS and to the vomiting center is lacking. Serotonin is released during rotavirus infection and antagonists to the serotonin receptor subtype 3 (5-HT3 receptor) can attenuate rotavirus-induced diarrhea. In this study we used a 5-HT3 receptor knockout (KO) mouse model to investigate the role of this receptor in rotavirus-induced diarrhea, motility, electrolyte secretion, inflammatory response and vomiting reflex. The number of diarrhea days (p=0.03) and the number of mice with diarrhea were lower in infected 5-HT3 receptor KO than wildtype pups. In vivo investigation of FITC-dextran transit time showed that intestinal motility was lower in the infected 5-HT3 receptor KO compared to wildtype mice (p=0.0023). Ex vivo Ussing chamber measurements of potential difference across the intestinal epithelia showed no significant difference in electrolyte secretion between the two groups. Immediate early gene cFos expression level showed no difference in activation of the vomiting center in the brain. Cytokine analysis of the intestine indicating low effect of inflammatory response in rotavirus-infected mice lacking the 5-HT3 receptor. Our findings indicate that the 5-HT3 receptor is involved in rotavirus-induced diarrhea via its effect on intestinal motility and that the vagus nerve signaling to the vomiting center occurs also in the absence of the 5-HT3 receptor. IMPORTANCE The mechanisms underlying rotavirus-induced diarrhea and vomiting are not yet fully understood. To better understand rotavirus pathophysiology, characterization of nerve signaling within the ENS and trough vagal efferent nerves to the brain, which have been shown to be of great importance to the disease, is necessary. Serotonin (5-HT), a mediator of both diarrhea and vomiting, has been shown to be released from enterochromaffin cells in response to rotavirus infection and the rotavirus enterotoxin NSP4. Here, we investigated the role of the serotonin receptor 5-HT3, which is known to be involved in the nerve signals that regulate gut motility, intestinal secretion, and signal transduction through the vagus nerve to the brain. We show that the 5-HT3 receptor is involved in rotavirus-induced diarrhea by promoting intestinal motility. The findings shed light on new treatment possibilities for rotavirus diarrhea.

The Role of Mitochondria in the Genesis of Neuroaxonal Dystrophy in the Brains of Aging Mice

1975 ◽  
Vol 33 ◽  
pp. 372-373
Author(s):  
J.E. Johnson
Keyword(s):  
Electron Microscopy ◽  
Present Report ◽  
Light And Electron Microscopy ◽  
Dorsal Column ◽  
Neuroaxonal Dystrophy ◽  
Nucleus Gracilis ◽  
Dystrophic Axons ◽  
The Brain ◽  
Nucleus Cuneatus

Although neuroaxonal dystrophy (NAD) has been examined by light and electron microscopy for years, the nature of the components in the dystrophic axons is not well understood. The present report examines nucleus gracilis and cuneatus (the dorsal column nuclei) in the brain stem of aging mice.Mice (C57BL/6J) were sacrificed by aldehyde perfusion at ages ranging from 3 months to 23 months. Several brain areas and parts of other organs were processed for electron microscopy.At 3 months of age, very little evidence of NAD can be discerned by light microscopy. At the EM level, a few axons are found to contain dystrophic material. By 23 months of age, the entire nucleus gracilis is filled with dystrophic axons. Much less NAD is seen in nucleus cuneatus by comparison. The most recurrent pattern of NAD is an enlarged profile, in the center of which is a mass of reticulated material (reticulated portion; or RP).

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