• Title/Summary/Keyword: microglia cells

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Microglial Contribution to Glioma Progression: an Immunohistochemical Study in Eastern India

  • Ghosh, Krishnendu;Ghosh, Samarendranath;Chatterjee, Uttara;Chaudhuri, Swapna;Ghosh, Anirban
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.6
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    • pp.2767-2773
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    • 2016
  • Human glioma, arising from glial cells of the central nervous system, accounts for almost 30%of all brain tumours, neoplasms with a poor prognosis and high mortality rates worldwide. In the present study we assessed tissue architectural modifications associated with macrophage lineage cells, controversial major immune effector cells within the brain, in human glioma tissue samples from eastern India. Ethically cleared post-operative human glioma samples from our collaborative neurosurgery unit with respective CT/MRI and patient history were collected from the Nodal Centre of Neurosciences in Kolkata, over 9 months. Along with conventional histopathology, samples were subjected to silver-gold staining and fluorescence tagged immunophenotyping for the detection of electron dense brain macrophage/microglia cells in glioma tissue, followed by immune-phenotyping of cells. With higher grades, CD11b+/Iba-1+ macrophage/microglia architecture with de-structured boundaries of glioma lesions indicated malfunction and invasive effector state. Present study documented a contribution of microglia to glioma progression in Eastern India.

Anti-inflammatory Effect of an Ethanolic Extract of Myagropsis yendoi in Lipopolysaccharide-Stimulated BV-2 Microglia Cells

  • Salih, Sarmad Ali;Kim, Hyeung-Rak
    • Fisheries and Aquatic Sciences
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    • v.17 no.1
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    • pp.27-35
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    • 2014
  • Marine brown algae have been identified as a rich source of structurally diverse bioactive compounds. Whether Myagropsis yendoi ethanolic extracts (MYE) inhibit inflammatory responses was investigated using lipopolysaccharide (LPS)-stimulated microglia BV-2 cells. MYE inhibited LPS-induced nitric oxide (NO) production in a dose-dependent manner and suppressed the expression of inducible nitric oxide synthase in BV-2 cells. MYE also reduced the production of pro-inflammatory cytokines in LPS-stimulated BV-2 cells. LPS-induced nuclear factor-${\kappa}B$ (NF-${\kappa}B$) transcriptional activity and NF-${\kappa}B$ translocation into the nucleus were significantly inhibited by MYE treatment through preventing degradation of the inhibitor ${\kappa}B-{\alpha}$. Moreover, MYE inhibited the phosphorylation of AKT, ERK, JNK, and p38 mitogen-activated protein kinase in LPS-stimulated BV-2 cells. These results indicate that MYE is a potential source of therapeutic or functional agents for neuroinflammatory diseases.

Inhibitory Action of Minocycline on Lipopolysaccharide-Induced Release of Nitric Oxide and Prostaglandin E2 in BV2 Microglial Cells

  • Kim, Sung-Soo;Kong, Pil-Jae;Kim, Bong-Seong;Sheen, Dong-Hyuk;Nam, Su-Youn;Chun, Wan-Joo
    • Archives of Pharmacal Research
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    • v.27 no.3
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    • pp.314-318
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    • 2004
  • Microglia are the major inflammatory cells in the central nervous system and become activated in response to brain injuries such as ischemia, trauma, and neurodegenerative diseases including Alzheimer's disease (AD). Moreover, activated microglia are known to release a variety of proinflammatory cytokines and oxidants such as nitric oxide (NO). Minocycline is a semi-synthetic second-generation tetracycline that exerts anti-inflammatory effects that are completely distinct form its antimicrobial action. In this study, the inhibitory effects of minocycline on NO and prostaglandin E$_2$ (PGE$_2$) release was examined in lipopolysaccharides (LPS)-challenged BV2 murine microglial cells. Further, effects of minocycline on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression levels were also determined. The results showed that minocycline significantly inhibited NO and PGE$_2$ production and iNOS and COX-2 expression in BV2 microglial cells. These findings suggest that minocycline should be evaluated as potential therapeutic agent for various pathological conditions due to the excessive activation of microglia.

Phagocytic Roles of Glial Cells in Healthy and Diseased Brains

  • Jung, Yeon-Joo;Chung, Won-Suk
    • Biomolecules & Therapeutics
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    • v.26 no.4
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    • pp.350-357
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    • 2018
  • Glial cells are receiving much attention since they have been recognized as important regulators of many aspects of brain function and disease. Recent evidence has revealed that two different glial cells, astrocytes and microglia, control synapse elimination under normal and pathological conditions via phagocytosis. Astrocytes use the MEGF10 and MERTK phagocytic pathways, and microglia use the classical complement pathway to recognize and eliminate unwanted synapses. Notably, glial phagocytosis also contributes to the clearance of disease-specific protein aggregates, such as ${\beta}$-amyloid, huntingtin, and ${\alpha}$-synuclein. Here we reivew recent findings showing that glial cells are active regulators in brain functions through phagocytosis and that changes in glial phagocytosis contribute to the pathogenesis of various neurodegenerative diseases. A better understanding of the cellular and molecular mechanisms of glial phagocytosis in healthy and diseased brains will greatly improve our current approach in treating these diseases.

Floridoside suppresses pro-inflammatory responses by blocking MAPK signaling in activated microglia

  • Kim, MinJeong;Li, Yong-Xin;Dewapriya, Pradeep;Ryu, BoMi;Kim, Se-Kwon
    • BMB Reports
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    • v.46 no.8
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    • pp.398-403
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    • 2013
  • Inflammatory conditions mediated by activated microglia lead to chronic neuro-degenerative diseases such as Alzheimer's, Parkinson's, and Huntington's diseases. This study was conducted to determine the effect of floridoside isolated from marine red algae Laurencia undulata on LPS (100 ng/ml) activated inflammatory responses in BV-2 microglia cells. The results show that floridoside has the ability to suppress pro-inflammatory responses in microglia by markedly inhibiting the production of nitric oxide (NO) and reactive oxygen species (ROS). Moreover, floridoside down-regulated the protein and gene expression levels of iNOS and COX-2 by significantly blocking the phosphorylation of p38 and ERK in BV-2 cells. Collectively, these results indicate that floridoside has the potential to be developed as an active agent for the treatment of neuro-inflammation.

Noni Inhibits Neuronal Damage Caused by the Immune Reaction of Microglial Cells Activated by Doxorubicin (Doxorubicin에 의해 활성화된 미세 아교세포의 면역반응으로 인한 신경손상에 Noni가 미치는 영향)

  • Jung, Se-Hwa;Lee, Seong-Min;Ha, Ji-Sun;Yang, Seung-Ju;Kim, Pyung-Hwan
    • Korean Journal of Clinical Laboratory Science
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    • v.52 no.4
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    • pp.389-397
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    • 2020
  • Microglial cells function as major immune cells in the brain, playing an important role in the protection and damage of neurons. BV2 microglia, activated by drug stimulation, secrete inflammatory cytokines by activating the nuclear factor kappa-light-chain-enhancer of the activated B cells pathway and are involved in neuroinflammatory and immune responses. The overactivation of microglia by stimuli can cause neuronal damage, leading to brain disease. Noni, a natural product, reduces the activity of microglia to prevent neuronal damage and is a potential natural medicine because it exerts excellent regeneration and anti-inflammatory effects on damaged cells. In this study, when noni was used to treat BV2 cells stimulated by the anti-cancer drug doxorubicin, it reduced the release of pro-inflammatory cytokines from BV2. On the other hand, neuronal damage is a side effect of doxorubicin. Therefore, the cytokines released from doxorubicin-stimulated BV2 cells treated with noni had a positive effect on the neuronal viability compared to those released from doxorubicin-stimulated BV2 cells not treated with Noni. Thus, Noni increases neuronal viability. These results suggest that noni inhibits the release of cytokines by regulating the nuclear factor kappa-light-chain-enhancer of the activated B cells pathway of BV2, thereby inhibiting neuronal damage.

Anti-Oxidative and Neuroprotective Effects of Rhei Rhizoma on BV-2 Microglia Cells and Hippocampal Neurons (대황(大黃)의 항산화와 신경세포손상 보호효능에 대한 연구)

  • Myung, Sung-Ha;Kim, Youn-Sub
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.3
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    • pp.647-655
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    • 2005
  • This study demonstrated anti-oxidative and neuroprotective effects of Rhei Rhizoma. Anti-oxidative effects were studied on BV-2 microglia cells damaged by $H_2O_2$ and nitric oxide. Neuroprotective effects were studied by using oxygen/glucose deprivation of the organotypic hippocampal slice cultures. The results obtained are as follows; The groups treated with 0.5 and 5 mg/ml of Puerariae Radix revealed significant decreases of neuronal cell death area and cell death area percentages in CA1 region of ischemic damaged hippocampus cultures during whole 48 hours of the experiment. The group treated with 50 mg/ml of Puerariae Radix demonstrated decreases of neuronal cell death area and cell death area percentages in CA1 region, but these were not significant statistically. The groups treated with 0.5 and 5 mg/ml of Puerariae Radix revealed significant decreases of neuronal cell death area and cell death area percentages in dentate gyrus of ischemic damaged hippocampus cultures during whole 48 hours of the experiment. The group treated with 50 mg/ml of Puerariae Radix demonstrated decreases of neuronal cell death area and cell death area percentages in dentate gyrus, but these were not significant statistically. The groups treated with 0.5 and 5 mg/ml of Puerariae Radix revealed significant decreases of TUNEL-positive cells in both CA1 region and dentate gyrus of ischemic damaged hippocampus cultures. The group treated with 50 mg/ml of Puerariae Radix demonstrated significant decrease of TUNEL-positive cells in CA1 region, but not in dentate gyrus of ischemic damaged hippocampus. The groups treated with 0.5 and 5 mg/ml of Puerariae Radix revealed significant decreases of LDH concentrations in culture media of ischemic damaged hippocampus cultures. The group treated with 50 mg/ml of Puerariae Radix demonstrated decrease of LDH concentrations in culture media, but it was not significant statistically. The groups treated with 0.5 and 5 mg/ml of Puerariae Radix revealed significant increases of cell viabilities of BV-2 microglia cells damaged by $H_2O_2$. The group treated with 50 mg/ml of Puerariae Radix demonstrated increase of cell viability of BV-2 microglia cells, but it was not significant statistically. The group treated with 0.5 mg/ml of Puerariae Radix revealed significant increase of cell viability of BV-2 microglia cells damaged by nitric oxide. The groups treated with 5 and 50 mg/ml of Puerariae Radix demonstrated increases of cell viabilities of BV-2 microglia cells, but these were not significant statistically. These results suggested that Puerariae Radix revealed neuroprotective effects through the control effect of apoptosis and oxidative damages.

Glial Mechanisms of Neuropathic Pain and Emerging Interventions

  • Jo, Daehyun;Chapman, C. Richard;Light, Alan R.
    • The Korean Journal of Pain
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    • v.22 no.1
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    • pp.1-15
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    • 2009
  • Neuropathic pain is often refractory to intervention because of the complex etiology and an incomplete understanding of the mechanisms behind this type of pain. Glial cells, specifically microglia and astrocytes, are powerful modulators of pain and new targets of drug development for neuropathic pain. Glial activation could be the driving force behind chronic pain, maintaining the noxious signal transmission even after the original injury has healed. Glia express chemokine, purinergic, toll-like, glutaminergic and other receptors that enable them to respond to neural signals, and they can modulate neuronal synaptic function and neuronal excitability. Nerve injury upregulates multiple receptors in spinal microglia and astrocytes. Microglia influence neuronal communication by producing inflammatory products at the synapse, as do astrocytes because they completely encapsulate synapses and are in close contact with neuronal somas through gap junctions. Glia are the main source of inflammatory mediators in the central nervous system. New therapeutic strategies for neuropathic pain are emerging such as targeting the glial cells, novel pharmacologic approaches and gene therapy. Drugs targeting microglia and astrocytes, cytokine production, and neural structures including dorsal root ganglion are now under study, as is gene therapy. Isoform-specific inhibition will minimize the side effects produced by blocking all glia with a general inhibitor. Enhancing the anti-inflammatory cytokines could prove more beneficial than administering proinflammatory cytokine antagonists that block glial activation systemically. Research on therapeutic gene transfer to the central nervous system is underway, although obstacles prevent immediate clinical application.

Chemical Constituents from the Aerial Parts of Artemisia absinthium and Its Inhibitory Effects of Nitric Oxide Production in RAW264.7 and BV2 Microglia (쓴쑥 지상부의 화학성분과 RAW264.7 및 BV2 미세아교세포에서 Nitric Oxide 생성 억제효과)

  • Ko, Hae Ju;Lee, Hwan;Lee, Dong-Sung;Woo, Eun-Rhan
    • Korean Journal of Pharmacognosy
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    • v.49 no.1
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    • pp.1-6
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    • 2018
  • Six compounds, eupatilin (1), dammaradienyl acetate (2), glutinol acetate (3), $3{\beta}-acetoxyoleanan-12-one$ (4), taraxasterol (5) and quercetin-3,4'-dimethyl ether (6) were isolated from the aerial parts of Artemisia absinthium. The chemical structures of compounds 1-6 were determined by the basis of physico-chemical properties and spectroscopic methods such as 1D and 2D NMR. Among them, compounds 2-5 were isolated from this plant for the first time. The inhibitory effects of these isolated compounds against nitric oxide (NO) production in LPS-induced RAW264.7 cells or BV2 microglia were also examined. Among the tested compounds, compound 1, eupatilin, inhibited the production of NO in LPS-induced RAW264.7 cells and BV2 microglia, respectively.

A New Neolignan Derivative, Balanophonin Isolated from Firmiana simplex Delays the Progress of Neuronal Cell Death by Inhibiting Microglial Activation

  • Lim, Soo Young;Subedi, Lalita;Shin, Dongyun;Kim, Chung Sub;Lee, Kang Ro;Kim, Sun Yeou
    • Biomolecules & Therapeutics
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    • v.25 no.5
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    • pp.519-527
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    • 2017
  • Excessive activation of microglia causes the continuous production of neurotoxic mediators, which further causes neuron degeneration. Therefore, inhibition of microglial activation is a possible target for the treatment of neurodegenerative disorders. Balanophonin, a natural neolignoid from Firmiana simplex, has been reported to have anti-inflammatory and anti-cancer effects. In this study, we aimed to evaluate the anti-neuroinflammatory effects and mechanism of balanophonin in lipopolysaccharide (LPS)-stimulated BV2 microglia cells. BV2 microglia cells were stimulated with LPS in the presence or absence of balanophonin. The results indicated that balanophonin reduced not only the LPS-mediated TLR4 activation but also the production of inflammatory mediators, such as nitric oxide (NO), prostaglandin E2 (PGE2), $Interleukin-1{\beta}$ ($IL-1{\beta}$), and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), in BV2 cells. Balanophonin also inhibited LPS-induced inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX2) protein expression and mitogen activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 MAPK. Interestingly, it also inhibited neuronal cell death resulting from LPS-activated microglia by regulating cleaved caspase-3 and poly ADP ribose polymerase (PARP) cleavage in N2a cells. In conclusion, our data indicated that balanophonin may delay the progression of neuronal cell death by inhibiting microglial activation.