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 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 Biomarkers for Microglial Activation in Alzheimer's Disease

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Ronald Lautner ◽  
Niklas Mattsson ◽  
Michael Schöll ◽  
Kristin Augutis ◽  
Kaj Blennow ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Microglial Activation ◽  
Inflammatory Responses ◽  
Innate Immune ◽  
First Line ◽  
The Central Nervous System ◽  
Underlying Mechanisms ◽  
The Brain ◽  
Neuroimaging Techniques

Intensive research over the last decades has provided increasing evidence for neuroinflammation as an integral part in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD). Inflammatory responses in the central nervous system (CNS) are initiated by activated microglia, representing the first line of the innate immune defence of the brain. Therefore, biochemical markers of microglial activation may help us understand the underlying mechanisms of neuroinflammation in AD as well as the double-sided qualities of microglia, namely, neuroprotection and neurotoxicity. In this paper we summarize candidate biomarkers of microglial activation in AD along with a survey of recent neuroimaging techniques.

scholarly journals Comparisons of neuroinflammation, microglial activation, and degeneration of the locus coeruleus-norepinephrine system in APP/PS1 and aging mice

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Song Cao ◽  
Daniel W. Fisher ◽  
Guadalupe Rodriguez ◽  
Tian Yu ◽  
Hongxin Dong
Keyword(s):  
Spinal Cord ◽  
Locus Coeruleus ◽  
Microglial Activation ◽  
Healthy Aging ◽  
Cell Types ◽  
Norepinephrine System ◽  
Protective Processes ◽  
The Central Nervous System ◽  
Brain And Spinal Cord ◽  
The Brain

Abstract Background The role of microglia in Alzheimer’s disease (AD) pathogenesis is becoming increasingly important, as activation of these cell types likely contributes to both pathological and protective processes associated with all phases of the disease. During early AD pathogenesis, one of the first areas of degeneration is the locus coeruleus (LC), which provides broad innervation of the central nervous system and facilitates norepinephrine (NE) transmission. Though the LC-NE is likely to influence microglial dynamics, it is unclear how these systems change with AD compared to otherwise healthy aging. Methods In this study, we evaluated the dynamic changes of neuroinflammation and neurodegeneration in the LC-NE system in the brain and spinal cord of APP/PS1 mice and aged WT mice using immunofluorescence and ELISA. Results Our results demonstrated increased expression of inflammatory cytokines and microglial activation observed in the cortex, hippocampus, and spinal cord of APP/PS1 compared to WT mice. LC-NE neuron and fiber loss as well as reduced norepinephrine transporter (NET) expression was more evident in APP/PS1 mice, although NE levels were similar between 12-month-old APP/PS1 and WT mice. Notably, the degree of microglial activation, LC-NE nerve fiber loss, and NET reduction in the brain and spinal cord were more severe in 12-month-old APP/PS1 compared to 12- and 24-month-old WT mice. Conclusion These results suggest that elevated neuroinflammation and microglial activation in the brain and spinal cord of APP/PS1 mice correlate with significant degeneration of the LC-NE system.

Cholecystokinin octapeptide analogues suppress food intake via central CCK-A receptors in mice

1993 ◽  
Vol 265 (3) ◽  
pp. R481-R486 ◽  
Author(s):  
Y. Hirosue ◽  
A. Inui ◽  
A. Teranishi ◽  
M. Miura ◽  
M. Nakajima ◽  
...  
Keyword(s):  
Food Intake ◽  
Receptor Antagonist ◽  
Rank Order ◽  
Peripheral Circulation ◽  
Inhibitory Effect ◽  
Peripheral Tissues ◽  
Cholecystokinin Octapeptide ◽  
The Central Nervous System ◽  
The Difference ◽  
The Brain

To examine the mechanism of the satiety-producing effect of cholecystokinin (CCK) in the central nervous system, we compared the potency of intraperitoneally (ip) or intracerebroventricularly (icv) administered CCK-8 and its analogues on food intake in fasted mice. The icv administration of a small dose of CCK-8 (0.03 nmol/brain) or of Suc-(Thr28, Leu29, MePhe33)-CCK-7 (0.001 nmol/brain) suppressed food intake for 20 min, whereas CCK-8 (1 nmol/kg, which is equivalent to 0.03 nmol/brain) or Suc-(Thr28, Leu29, MePhe33)-CCK-7 (1 nmol/kg) had satiety effect after ip administration. Dose-response studies indicated the following rank order of potency: Suc-CCK-7 > or = Suc-(Thr28, Leu29, MePhe33)-CCK-7 > or = CCK-8 > or = (Nle28,31)-CCK-8 >> desulfated CCK-8 = CCK-4 = 0 in the case of ip administration and Suc-(Thr28, Leu29, MePhe33)-CCK-7 >> Suc-CCK-7 > or = CCK-8 > or = (Nle28,31)-CCK-8 >> desulfated CCK-8 = CCK-4 = 0 in the case of icv administration. The selective CCK-A receptor antagonist MK-329 reversed the inhibitory effect of the centrally as well as peripherally administered CCK-8, or of Suc-(Thr28, Leu29, MePhe33)-CCK-7, whereas the selective CCK-B receptor antagonist L-365260 did not. The icv administered CCK-8 did not appear in the peripheral circulation. These findings suggest the participation of CCK-A receptors in the brain in mediating the satiety effect of CCK and the difference in CCK-A receptors in the brain and peripheral tissues.

scholarly journals Neuronal MCP-1 Expression in Response to Remote Nerve Injury

2001 ◽  
Vol 21 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Alexander Flügel ◽  
Gerhard Hager ◽  
Andrea Horvat ◽  
Christoph Spitzer ◽  
Gamal M. A. Singer ◽  
...  
Keyword(s):  
T Cell ◽  
Inflammatory Responses ◽  
Nerve Lesion ◽  
Monocyte Chemoattractant ◽  
Direct Injury ◽  
Inflammatory Activation ◽  
The Central Nervous System ◽  
Inducible Protein ◽  
The Brain

Direct injury of the brain is followed by inflammatory responses regulated by cytokines and chemoattractants secreted from resident glia and invading cells of the peripheral immune system. In contrast, after remote lesion of the central nervous system, exemplified here by peripheral transection or crush of the facial and hypoglossal nerve, the locally observed inflammatory activation is most likely triggered by the damaged cells themselves, that is, the injured neurons. The authors investigated the expression of the chemoattractants monocyte chemoattractant protein MCP-1, regulation on activation normal T-cell expressed and secreted (RANTES), and interferon-gamma inducible protein IP10 after peripheral nerve lesion of the facial and hypoglossal nuclei. In situ hybridization and immunohistochemistry revealed an induction of neuronal MCP-1 expression within 6 hours postoperation, reaching a peak at 3 days and remaining up-regulated for up to 6 weeks. MCP-1 expression was almost exclusively confined to neurons but was also present on a few scattered glial cells. The authors found no alterations in the level of expression and cellular distribution of RANTES or IP10, which were both confined to neurons. Protein expression of the MCP-1 receptor CCR2 did not change. MCP-1, expressed by astrocytes and activated microglia, has been shown to be crucial for monocytic, or T-cell chemoattraction, or both. Accordingly, expression of MCP-1 by neurons and its corresponding receptor in microglia suggests that this chemokine is involved in neuron and microglia interaction.

Cytosolic phospholipase A2α regulates induction of brain cyclooxygenase-2 in a mouse model of inflammation

2005 ◽  
Vol 288 (6) ◽  
pp. R1774-R1782 ◽  
Author(s):  
Adam Sapirstein ◽  
Hideyuki Saito ◽  
Sarah J. Texel ◽  
Tarek A. Samad ◽  
Eileen O’Leary ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Inflammatory Responses ◽  
Arachidonic Acid Metabolism ◽  
Cyclooxygenase 2 ◽  
Phospholipase A ◽  
Wild Type ◽  
Cytosolic Phospholipase ◽  
The Central Nervous System ◽  
Cox 2 ◽  
The Brain

The products of arachidonic acid metabolism are key mediators of inflammatory responses in the central nervous system, and yet we do not know the mechanisms of their regulation. The phospholipase A2 enzymes are sources of cellular arachidonic acid, and the enzymes cyclooxygenase-2 (COX-2) and microsomal PGE synthase-1 (mPGES-1) are essential for the synthesis of inflammatory PGE2 in the brain. These studies seek to determine the function of cytosolic phospholipase A2α (cPLA2α) in inflammatory PGE2 production in the brain. We wondered whether cPLA2α functions in inflammation to produce arachidonic acid or to modulate levels of COX-2 or mPGES-1. We investigated these questions in the brains of wild-type mice and mice deficient in cPLA2α (cPLA2α−/−) after systemic administration of LPS. cPLA2α−/− mice had significantly less brain COX-2 mRNA and protein expression in response to LPS than wild-type mice. The reduction in COX-2 was most apparent in the cells of the cerebral blood vessels and the leptomeninges. The brain PGE2 concentration of untreated cPLA2α−/− mice was equal to their wild-type littermates. After LPS treatment, however, the brain concentration of PGE2 was significantly less in cPLA2α−/− than in cPLA2α+/+ mice (24.4 ± 3.8 vs. 49.3 ± 11.6 ng/g). In contrast to COX-2, mPGES-1 RNA levels increased equally in both mouse genotypes, and mPGES-1 protein was unaltered 6 h after LPS. We conclude that cPLA2α regulates COX-2 levels and modulates inflammatory PGE2 levels. These results indicate that cPLA2α inhibition is a novel anti-inflammatory strategy that modulates, but does not completely prevent, eicosanoid responses.

scholarly journals Upregulation of lncRNA147410.3 in the Brain of Mice With Chronic Toxoplasma Infection Promoted Microglia Apoptosis by Regulating Hoxb3

2021 ◽  
Vol 15 ◽  
Author(s):  
Yongliang Wang ◽  
Ruxia Han ◽  
Zhejun Xu ◽  
Xiahui Sun ◽  
Chunxue Zhou ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Target Gene ◽  
Neuronal Cell ◽  
Scientific Basis ◽  
Cns Development ◽  
Toxoplasma Infection ◽  
Key Factor ◽  
The Central Nervous System ◽  
The Brain

Toxoplasma gondii is neurotropic and affects the function of nerve cells, while the mechanism is unclear. LncRNAs are abundantly enriched in the brain and participated in the delicate regulation of the central nervous system (CNS) development. However, whether these lncRNAs are involved in the regulation of microglia activation during the process of T. gondii infection is largely unknown. In this study, the upregulation of a novel lncRNA147410.3 (ENSMUST00000147410.3) was identified as a key factor to influence this process. The target gene of lncRNA147410.3 was predicted and identified as Hoxb3. The localization of lncRNA147410.3 in the brain and cells was proved in the nucleus of neuroglia through FISH assay. Furthermore, the function of lncRNA147410.3 on neuronal cell was confirmed that lncRNA147410.3 could affect proliferation, differentiation, and apoptosis of mouse microglia by positively regulating Hoxb3. Thus, our study explored the modulatory action of lncRNA147410.3 in T. gondii infected mouse brain, providing a scientific basis for using lncRNA147410.3 as a therapeutic target to treat neurological disorder induced by T. gondii.

scholarly journals Brain HIV-1 latently-infected reservoirs targeted by the suicide gene strategy

2020 ◽  
Author(s):  
Sepideh Saeb ◽  
Mehrdad Ravanshad ◽  
Mahmoud Reza Pourkarim ◽  
Fadoua Daouad ◽  
Kazem Baesi ◽  
...  
Keyword(s):  
Suicide Gene ◽  
Microglial Cells ◽  
Peripheral Tissues ◽  
Latently Infected ◽  
Shock And Kill ◽  
The Central Nervous System ◽  
Infected Cells ◽  
Set Up ◽  
The Brain ◽  
Hiv 1

Abstract Several strategies are currently investigated to reduce the pool of all HIV-1 reservoirs in infected patients in order to achieve functional cure. The most prominent HIV-1 cell reservoirs in the brain are microglial cells. Virus infection maybe lifelong. Infected microglial cells are believed to be the source of peripheral tissues reseeding and responsible for the emergence of drug resistance. Clearing infected cells from the brain is therefore crucial. However, many characteristics of microglial cells and the central nervous system prevent the eradication of brain reservoirs. Current trials, such as “shock and kill”, the “deep and lock” and the gene editing strategies do not respond to these difficulties. Therefore, new strategies have to be designed when considering brain reservoirs such as microglial cells. We set up an original gene suicide strategy using a latently infected microglial model. In this paper we provide proof of concept of this strategy. Our results demonstrate that this strategy enables the eradication of latently-infected microglial cells.

Arachidonic Acid Derivatives and Neuroinflammation

2021 ◽  
Vol 20 ◽  
Author(s):  
Era Gorica ◽  
Vincenzo Calderone
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Arachidonic Acid ◽  
Prostaglandin E2 ◽  
Phospholipase A2 ◽  
Inflammatory Responses ◽  
The Central Nervous System ◽  
The Brain ◽  
Arachidonic Acid Derivatives

: Neuroinflammation is characterized by dysregulated inflammatory responses localized within the brain and spinal cord. Neuroinflammation plays a pivotal role in the onset of several neurodegenerative disorders and is considered a typical feature of these disorders. Microglia perform primary immune surveillance and macrophage-like activities within the central nervous system. Activated microglia are predominant players in the central nervous system response to damage related to stroke, trauma, and infection. Moreover, microglial activation per se leads to a proinflammatory response and oxidative stress. During the release of cytokines and chemokines, cyclooxygenases and phospholipase A2 are stimulated. Elevated levels of these compounds play a significant role in immune cell recruitment into the brain. Cyclic phospholipase A2 plays a fundamental role in the production of prostaglandins by releasing arachidonic acid. In turn, arachidonic acid is biotransformed through different routes into several mediators that are endowed with pivotal roles in the regulation of inflammatory processes. Some experimental models of neuroinflammation exhibit an increase in cyclic phospholipase A2, leukotrienes, and prostaglandins such as prostaglandin E2, prostaglandin D2, or prostacyclin. However, findings on the role of the prostacyclin receptors have revealed that their signalling suppresses Th2-mediated inflammatory responses. In addition, other in vitro evidence suggests that prostaglandin E2 may inhibit the production of some inflammatory cytokines, attenuating inflammatory events such as mast cell degranulation or inflammatory leukotriene production. Based on these conflicting experimental data, the role of arachidonic acid derivatives in neuroinflammation remains a challenging issue.

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