Carrageenan-induced brain inflammation

1986 ◽  
Vol 65 (5) ◽  
pp. 679-685 ◽  
Author(s):  
Daniel A. Gamache ◽  
John T. Povlishock ◽  
Earl F. Ellis
Keyword(s):  
Arachidonic Acid ◽  
Vascular Permeability ◽  
Brain Inflammation ◽  
Intraventricular Injection ◽  
Arachidonic Acid Metabolite ◽  
Maximum Increase ◽  
Peripheral Tissues ◽  
Neutrophil Extravasation ◽  
Anti Inflammatory ◽  
The Brain

✓ Administration of the mucopolysaccharide, carrageenan (CAR), into the hind paw of the rat or mouse induces a local inflammation characterized by increased arachidonic acid metabolism, increased vascular permeability, edema, and neutrophil extravasation. Carrageenan-induced hind-paw inflammation is inhibited by prostaglandin synthesis inhibitors, and this assay predicts the clinical success of anti-inflammatory agents in reducing peripheral inflammation. The purpose of this study was to determine if intraventricular injection of CAR would induce brain inflammation similar to that evoked by CAR in peripheral tissues. The present study demonstrates that CAR injection into the ventricles of the mouse brain does in fact induce an inflammatory response very similar to that caused by injection of CAR into the peripheral tissues. The brain response to CAR was dose-dependent, with the maximum increase in cerebrovascular permeability to iodine-125-labeled human serum albumin and percent brain water occurring after injection of 50 µg CAR. As is seen in CAR-induced inflammation of the hind paw, the maximum increase in brain vascular permeability occurred 4 hours after CAR injection. Histological analysis of brains 4 hours after CAR administration showed global neutrophil extravasation into the subarachnoid space and evidence of focal neuronal swelling. Methotrexate-induced neutropenia, however, failed to diminish the permeability response to CAR. Gas chromatographic and mass spectrometric measurements of brain prostaglandins 4 hours after CAR injection revealed a significantly increased level of 6-keto-prostaglandin F1α. These results indicate that a significant increase in prostacyclin, the pro-inflammatory arachidonic acid metabolite, during CAR-induced brain inflammation is likely. These studies suggest that CAR-induced brain inflammation may be a useful model on which to test the efficacy of anti-inflammatory agents in the brain, as well as providing information concerning the mediators and mechanisms by which the brain may sustain inflammatory injury.

Effect of dexamethasone, indomethacin, ibuprofen, and probenecid on carrageenan-induced brain inflammation

1986 ◽  
Vol 65 (5) ◽  
pp. 686-692 ◽  
Author(s):  
Daniel A. Gamache ◽  
Earl F. Ellis
Keyword(s):  
Vascular Permeability ◽  
Brain Inflammation ◽  
Intraventricular Injection ◽  
Normal Brain ◽  
Synthesis Inhibitor ◽  
Peripheral Tissues ◽  
Content Type ◽  
Carbon 14 ◽  
Brain Water ◽  
Fine Print

✓ A model of brain inflammation has recently been developed in mice using intraventricular injection of carrageenan (CAR). This model is characterized by increased brain water and vascular permeability, by neutrophil extravasation, and by evidence of increased pro-inflammatory arachidonic acid metabolites. The purpose of the current experiments was to determine the mechanism(s) by which CAR induces brain inflammation and to determine the utility of the CAR model in testing systemically administered therapeutic agents for their capacity to inhibit brain inflammation. Dexamethasone inhibited the increased brain water but not the increased vascular permeability produced by CAR. Indomethacin, an inhibitor of prostaglandin formation, suppressed peripheral inflammation produced by local injection of CAR but not brain inflammation produced by intraventricular CAR injection. Subsequent studies with carbon-14-labeled indomethacin showed that indomethacin penetrates peripheral tissues but is excluded from normal brain or brains inflamed by injection of CAR. Ibuprofen, another prostaglandin synthesis inhibitor, also had no effect on brain inflammation. Probenecid, an organic acid transport inhibitor, completely inhibited CAR-induced brain inflammation and also slowed brain elimination of intraventricularly administered prostaglandins. These experiments suggest, but do not conclusively prove, that increased prostaglandin formation contributes to brain inflammation. Also, the results with indomethacin and CAR-induced brain inflammation indicate that CAR-induced inflammation may be a useful model for screening for the ability of anti-inflammatory agents to cross the blood-brain barrier and exert their effect on brain inflammation.

Death receptors on reactive astrocytes

Neurology ◽  
2003 ◽  
Vol 60 (4) ◽  
pp. 548-554 ◽  
Author(s):  
Pierre-Yves Dietrich ◽  
Paul R. Walker ◽  
Philippe Saas
Keyword(s):  
Brain Injury ◽  
Immune Responses ◽  
Death Receptors ◽  
Reactive Astrocytes ◽  
Brain Inflammation ◽  
Fine Tuning ◽  
Immune Mediated ◽  
Anti Inflammatory ◽  
The Brain

Immune responses protect the CNS against pathogens. However, the fact that there is little dispensable tissue in the brain makes regulation necessary to avoid disastrous immune-mediated damage. Astrocytes respond vigorously to any brain injury (e.g., tumor, stroke, AD, MS, HIV) and are postulated to play an important role in the fine tuning of brain inflammation. The authors propose that astrocytes use death receptors to modulate pro- and anti-inflammatory effects.

scholarly journals Behavioural Fever Promotes an Inflammatory Reflex Circuit in Ectotherms

2021 ◽  
Vol 22 (16) ◽  
pp. 8860
Author(s):  
Nataly Sanhueza ◽  
Ricardo Fuentes ◽  
Andrea Aguilar ◽  
Beatriz Carnicero ◽  
Karina Vega ◽  
...  
Keyword(s):  
Viral Infection ◽  
Inflammatory Responses ◽  
Expression Patterns ◽  
Inflammatory Factors ◽  
Peripheral Tissues ◽  
Network Activation ◽  
Entry Points ◽  
Anti Inflammatory ◽  
The Brain

Background: The communication between the brain and the immune system is a cornerstone in animal physiology. This interaction is mediated by immune factors acting in both health and pathogenesis, but it is unclear how these systems molecularly and mechanistically communicate under changing environmental conditions. Behavioural fever is a well-conserved immune response that promotes dramatic changes in gene expression patterns during ectotherms’ thermoregulatory adaptation, including those orchestrating inflammation. However, the molecular regulators activating the inflammatory reflex in ectotherms remain unidentified. Methods: We revisited behavioural fever by providing groups of fish a thermal gradient environment during infection. Our novel experimental setup created temperature ranges in which fish freely moved between different thermal gradients: (1) wide thermoregulatory range; T° = 6.4 °C; and (2) restricted thermoregulatory range; T° = 1.4 °C. The fish behaviour was investigated during 5-days post-viral infection. Blood, spleen, and brain samples were collected to determine plasmatic pro- and anti-inflammatory cytokine levels. To characterize genes’ functioning during behavioural fever, we performed a transcriptomic profiling of the fish spleen. We also measured the activity of neurotransmitters such as norepinephrine and acetylcholine in brain and peripheral tissues. Results: We describe the first set of the neural components that control inflammatory modulation during behavioural fever. We identified a neuro-immune crosstalk as a potential mechanism promoting the fine regulation of inflammation. The development of behavioural fever upon viral infection triggers a robust inflammatory response in vivo, establishing an activation threshold after infection in several organs, including the brain. Thus, temperature shifts strongly impact on neural tissue, specifically on the inflammatory reflex network activation. At the molecular level, behavioural fever causes a significant increase in cholinergic neurotransmitters and their receptors’ activity and key anti-inflammatory factors such as cytokine Il10 and Tgfβ in target tissues. Conclusion: These results reveal a cholinergic neuronal-based mechanism underlying anti-inflammatory responses under induced fever. We performed the first molecular characterization of the behavioural fever response and inflammatory reflex activation in mobile ectotherms, identifying the role of key regulators of these processes. These findings provide genetic entry points for functional studies of the neural–immune adaptation to infection and its protective relevance in ectotherm organisms.

scholarly journals Exercise conditioned plasma dampens inflammation via clusterin and boosts memory

2019 ◽  
Author(s):  
Zurine De Miguel ◽  
Michael J. Betley ◽  
Drew Willoughby ◽  
Benoit Lehallier ◽  
Niclas Olsson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cognitive Aging ◽  
Animal Health ◽  
Brain Inflammation ◽  
Cognitively Impaired ◽  
Complement Cascade ◽  
Striking Increase ◽  
Cognitive Benefits ◽  
Anti Inflammatory ◽  
The Brain

Physical exercise seems universally beneficial to human and animal health, slowing cognitive aging and neurodegeneration. Cognitive benefits are tied to increased plasticity and reduced inflammation within the hippocampus, yet little is known about the factors and mechanisms mediating these effects. We discovered “runner” plasma, collected from voluntarily running mice, infused into sedentary mice recapitulates the cellular and functional benefits of exercise on the brain. Importantly, runner plasma reduces baseline neuroinflammatory gene expression and prominently suppresses experimentally induced brain inflammation. Plasma proteomic analysis shows a striking increase in complement cascade inhibitors including clusterin, which is necessary for the anti-inflammatory effects of runner plasma. Cognitively impaired patients participating in structured exercise for 6 months showed higher plasma clusterin levels, which correlated positively with improvements in endurance and aerobic capacity. These findings demonstrate the existence of anti-inflammatory “exercise factors” that are transferrable, benefit the brain, and are present in humans engaging in exercise.

scholarly journals Neuroprotective and Anti-Microglial Activation Effects of Tocotrienols in Brains of Lipopolysaccharide-Induced Inflammatory Model Mice

Neuroglia ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 89-97
Author(s):  
Satoshi Okuyama ◽  
Masafumi Matsuda ◽  
Yuna Okusako ◽  
Sanae Miyauchi ◽  
Toshiki Omasa ◽  
...  
Keyword(s):  
Microglial Activation ◽  
Inflammatory Responses ◽  
Neuronal Cell ◽  
Vesicle Membrane ◽  
Peripheral Tissues ◽  
Cell Dysfunction ◽  
Stratum Lucidum ◽  
The Central Nervous System ◽  
Anti Inflammatory ◽  
The Brain

Inflammation is the cause and/or result of many diseases in peripheral tissues and the central nervous system. Recent findings suggested that inflammation in peripheral tissue induces an inflammatory response in the brain that activates glial cells, which, in turn, induce neuronal cell dysfunction. Therefore, anti-inflammatory compounds are important for the suppression of chronic inflammation and prevention of disease. The present study revealed microglial activation in the hippocampus of the brain two days after the peripheral administration of lipopolysaccharide (LPS). Furthermore, the expression of the synaptic vesicle membrane protein, synaptophysin, in the CA3 stratum lucidum of the hippocampus was down-regulated 7 days after the LPS injection. The administration of tocotrienols, a type of vitamin E, significantly attenuated these changes in the hippocampus. Collectively, the present results demonstrated the spread of peripheral inflammatory responses to the brain, in which glial activation and neuronal dysfunction were induced, while tocotrienols exerted anti-inflammatory effects and protected neurons from damage.

scholarly journals Inhibitory Effects of Auraptene and Naringin on Astroglial Activation, Tau Hyperphosphorylation, and Suppression of Neurogenesis in the Hippocampus of Streptozotocin-Induced Hyperglycemic Mice

Antioxidants ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 109 ◽  
Author(s):  
Satoshi Okuyama ◽  
Tatsumi Nakashima ◽  
Kumi Nakamura ◽  
Wakana Shinoka ◽  
Maho Kotani ◽  
...  
Keyword(s):  
Related Compound ◽  
Tau Hyperphosphorylation ◽  
Neuroprotective Agents ◽  
Inhibitory Effects ◽  
Peripheral Tissues ◽  
Anti Inflammatory ◽  
Astroglial Activation ◽  
The Brain ◽  
Antioxidant Effects ◽  
Extensive Damage

Auraptene, a citrus-related compound, exerts anti-inflammatory effects in peripheral tissues, and we demonstrated these effects in the brains of a lipopolysaccharide-injected systemic inflammation animal model and a brain ischemic mouse model. Naringin, another citrus-related compound, has been shown to exert antioxidant effects in several animal models. Hyperglycemia induces oxidative stress and inflammation and causes extensive damage in the brain; therefore, we herein evaluated the anti-inflammatory and other effects of auraptene and naringin in streptozotocin-induced hyperglycemic mice. Both compounds inhibited astroglial activation and the hyperphosphorylation of tau at 231 of threonine in neurons, and also recovered the suppression of neurogenesis in the dentate gyrus of the hippocampus in hyperglycemic mice. These results suggested that auraptene and naringin have potential effects as neuroprotective agents in the brain.

scholarly journals Modeling temperature- and Cav3 subtype-dependent alterations in T-type calcium channel mediated burst firing

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Fernando R. Fernandez ◽  
Mircea C. Iftinca ◽  
Gerald W. Zamponi ◽  
Ray W. Turner
Keyword(s):  
Calcium Channel ◽  
Neuronal Excitability ◽  
Neuronal Firing ◽  
Mammalian Brain ◽  
Peripheral Tissues ◽  
Window Current ◽  
Modeling Data ◽  
The Brain ◽  
Firing Neuron ◽  
Cav3 Channel

AbstractT-type calcium channels are important regulators of neuronal excitability. The mammalian brain expresses three T-type channel isoforms (Cav3.1, Cav3.2 and Cav3.3) with distinct biophysical properties that are critically regulated by temperature. Here, we test the effects of how temperature affects spike output in a reduced firing neuron model expressing specific Cav3 channel isoforms. The modeling data revealed only a minimal effect on baseline spontaneous firing near rest, but a dramatic increase in rebound burst discharge frequency for Cav3.1 compared to Cav3.2 or Cav3.3 due to differences in window current or activation/recovery time constants. The reduced response by Cav3.2 could optimize its activity where it is expressed in peripheral tissues more subject to temperature variations than Cav3.1 or Cav3.3 channels expressed prominently in the brain. These tests thus reveal that aspects of neuronal firing behavior are critically dependent on both temperature and T-type calcium channel subtype.

Thiamine transport in the central nervous system

1976 ◽  
Vol 230 (4) ◽  
pp. 1101-1107 ◽  
Author(s):  
R Spector
Keyword(s):  
Choroid Plexus ◽  
Intraventricular Injection ◽  
Simple Diffusion ◽  
Thiamine Transport ◽  
Choroid Plexuses ◽  
The Central Nervous System ◽  
The Brain ◽  
Thiamine Phosphates

Total thiamine (free thiamine and thiamine phosphates) transport into the cerebrospinal fluid (CSF), brain, and choroid plexus and out of the CSF was measured in rabbits. In vivo, total thiamine transport into CSF, choroid plexus, and brain was saturable. At the normal plasma total thiamine concentration, less than 5% of total thiamine entry into CSF, choroid plexus, and brain was by simple diffusion. The relative turnovers of total thiamine in choroid plexus, whole brain, and CSF were 5, 2, and 14% per h, respectively, when measured by the penetration of 35S-labeled thiamine injected into blood. From the CSF, clearance of [35S]thiamine relative to mannitol was not saturable after the intraventricular injection of various concentrations of thiamine. However, a portion of the [35S]thiamine cleared from the CSF entered brain by a saturable mechanism. In vitro, choroid plexuses, isolated from rabbits and incubated in artificial CSF, accumulated [35S]thiamine against a concentration gradient by an active saturable process that did not depend on pyrophosphorylation of the [35S]thiamine. The [35S]thiamine accumulated within the choroid plexus in vitro was readily released. These results were interpreted as showing that the entry of total thiamine into the brain and CSF from blood is regulated by a saturable transport system, and that the locus of this system may be, in part, in the choroid plexus.

Protective role of protocatechuic acid in carbon tetrachloride-induced oxidative stress via modulation of proinflammatory cytokines levels in brain and liver of Wistar rats

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Anne A. Adeyanju ◽  
Folake O. Asejeje ◽  
Olorunfemi R. Molehin ◽  
Olatunde Owoeye ◽  
Esther O. Olatoye ◽  
...  
Keyword(s):  
Cholesterol Level ◽  
Protocatechuic Acid ◽  
Liver Toxicity ◽  
Total Cholesterol Level ◽  
Density Lipoprotein ◽  
Albino Rats ◽  
Antioxidant Enzyme Activities ◽  
Cox 2 ◽  
Anti Inflammatory ◽  
The Brain

Abstract Objectives Protocatechuic acid (PCA) possesses numerous pharmacological activities, including antioxidative and anti-inflammatory activities. This study seeks to investigate its underlying mechanism of action in the liver and brain toxicity induced by CCl4 in male albino rats. Methods Rats were given PCA at 10 and 20 mg/kg daily and orally as a pretreatment for seven days. A single injection of CCl4 was given 2 h later to induce brain and liver toxicity. Results CCl4 moderately elevated the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). PCA lowered AST level significantly when compared to control. Total protein and albumin levels presented insignificant changes (p>0.05) in all groups while lipid profile showed increased total cholesterol level and reduced high-density lipoprotein (HDL) by CCl4. PCA (10 mg/kg) significantly reduced the cholesterol level while the 20 mg/kg dose moderately prevented HDL reduction. There was an increased MDA production with a corresponding low GSH level in the group treated with CCl4. Activities of superoxide dismutase, catalase, and glutathione-S-transferase in both organs also declined. PCA, especially at 10 mg/kg attenuated lipid peroxidation by increasing GSH level in the organs. Biochemical assays revealed the improvement of antioxidant enzyme activities by PCA in these organs. Furthermore, PCA lowered the level of proinflammatory cytokine COX 2 in the brain and liver while NF-kB expression was inhibited in the brain. Histopathology reports validated the effects of PCA. Conclusions PCA exhibited protection against toxicity in these tissues through antioxidant and anti-inflammatory activities and the potential mechanism might be through modulation of the NF-κB/COX-2 pathway.

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