• Title/Summary/Keyword: microglia

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Anti-Inflammatory Effect on Rat Microglia by UDCA

  • Joo, Seong-Soo;Oh, Won-Sik;Lee, Do-Ik
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.207.1-207.1
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    • 2003
  • Ursodeoxycholic acid (UDCA) has been known commonly improving hyperbilirubinemia and excretion abnormality of bromsulphalein, which are appeared in the liver, and reducing the release of cholesterol from bile duct. In our study, UDCA was aimed to know if the agent can inhibit the pathogenesis of AD by suppressing the microglial activation when stimulated particularly by A${\beta}$ peptide, which is known a major cause of AD. (omitted)

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Minocycline Directly Blocks Activation of Caspases After Oxidative Stress in PC12 Cells

  • Choi, Yu-Keum;Kim, Gab-Seok;Han, Byung-Hee
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.79.2-79.2
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    • 2003
  • Minocycline is known to protect neurons from microglia-mediated cell death in many experimental models of brain diseases including ischemic stroke, Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), traumatic brain injury, multiple sclerosis, and Parkinson's disease. Activation of caspase-2, 3, 8, and 9 was evident within 2-8 hr following oxidative insult with 0.5 mM hydrogen peroxide in PC12 cells. Minocycline significantly attenuated activation of these caspases up to 18 hr, resulting a significant increase in cell viability as assessed by MTT assay. (omitted)

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Effects of different parts of Angelica gigas Nakai on brain damages and neuronal death in transient middle artery occlusion/reperfusion-induced ischemic rats (허혈성 뇌졸중 흰쥐에서 당귀의 부위에 따른 뇌신경보호효과 비교 연구)

  • Shin, Yong-Joon;Park, Yong-Ki
    • The Korea Journal of Herbology
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    • v.29 no.6
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    • pp.85-93
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    • 2014
  • Objectives : We compared with the effects of different parts (root head, root body and hairy root) of Angelica gigas Nakai (Angelicae Gigantis Radix, AG) with on middle cerebral artery occlusion(MCAO)-induced ischemic rats, and on LPS-induced inflammatory response in BV2 microglia. Methods : The 30% ethanol and water extracts of different parts of AG were prepared. Each extract (50 and 100 mg/kg) was administrated intraperitoneally once in MCAO-induced ischemic rats. We measured infarction volumes by TTC staining, and investigated the expression of iNOS, Bax, Bcl-2 and caspase-3 by Western blot. BV2 cells were treated with each extract for 30 min, and then stimulated with LPS. The levels of NO was measured by Griess assay. The expression of iNOS, Cox-2 and proinflammatory cytokines ($TNF-{\alpha}$, $IL-1{\beta}$, and IL-6) were determined RT-PCR and Western blot. The phosphorylation of ERK1/2 and JNK MAPK was determined by Western blot. Results : Among different parts of AG, the 30% ethanol and water extracts of hairy root significantly decreased infarction volume in ischemic brains and inhibited the expression of iNOS, bax and caspase-3. The extracts of hairy root significantly inhibited LPS-induced production of NO, $TNF-{\alpha}$ and IL-6 in BV2 cells, and suppressed the expression of iNOS and COX-2. The hairy root extracts attenuated LPS-induced phosphorylation of ERK1/2 and JNK MAPK in BV2 cells. Conclusions : Our results indicate that the root hairy of AG has a good neuroprotective and anti-inflammatory effects in ischemic stroke compared to other parts.

Glia Dose not Participate in Antinociceptive Effects of Gabapentin in Rats with Trigeminal Neuropathic Pain

  • Yang, Kui-Y.;Kim, Hak-K.;Jin, Myoung-U.;Ju, Jin-S.;Ahn, Dong-K.
    • International Journal of Oral Biology
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    • v.37 no.3
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    • pp.121-129
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    • 2012
  • Previous clinical studies have demonstrated that gabapentin, a drug that binds to the voltage-gated calcium channel ${\alpha}2{\delta}1$ subunit proteins, is effective in the management of neuropathic pain, but there is limited evidence that addresses the participation of glial cells in the antiallodynic effects of this drug. The present study investigated the participation of glial cells in the anti-nociceptive effects of gabapentin in rats with trigeminal neuropathic pain produced by mal-positioned dental implants. Under anesthesia, the left mandibular second molar was extracted and replaced by a miniature dental implant to induce injury to the inferior alveolar nerve. Mal-positioned dental implants significantly decreased the air-puff thresholds both ipsilateral and contralateral to the injury site. Gabapentin was administered intracisternally beginning on postoperative day (POD) 1 or on POD 7 for three days. Early or late treatment with 0.3, 3, or 30 ${\mu}g$ of gabapentin produced significant anti-allodynic effect in the rats with mal-positioned dental implants. On POD 9, in the mal-positioned dental implants group, OX-42, a microglia marker, and GFAP, an astrocyte marker, were found to be up-regulated in the medullary dorsal horn, compared with the naive group. However, the intracisternal administration of gabapentin (30 ${\mu}g$) failed to reduce the number of activated microglia or astrocytes in the medullary dorsal horn. These findings suggest that gabapentin produces significant antinociceptive effects, which are not mediated by the inhibition of glial cell function in the medullary dorsal horn, in a rat model of trigeminal neuropathic pain.

Inhibition of iNOS Expression Via Ursodeoxycholic Acid in Murine Microglial Cell, BV-2 Cell Line (생쥐 소교세포(BV-2)에서 우르소데옥시콜린산에 의한 iNOS 발현억제)

  • Joo, Seong-Soo;Won, Tae-Joon;Hwang, Kwang-Woo;Lee, Do-Ik
    • IMMUNE NETWORK
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    • v.5 no.1
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    • pp.45-49
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    • 2005
  • Background: Inflammation in the brain has known to be associated with the development of a various neurological diseases. The hallmark of neuro-inflammation is the activation of microglia, brain macrophage. Pro-inflammatory compounds including nitric oxide (NO) are the main cause of neuro-degenerative disease such as Alzheimer's disease (AD) which is resulted in cell death. Among those pro-inflammatory compounds, NO contributes to the cell death by directly or indirectly. Methods: In the study, we examined whether ursodeoxycholic acid (UDCA), a non-toxic hydrophilic bile acid, inhibits the NO production by a direct method using Griess reagent and by RT-PCR in the gene expression of inducible nitric oxide synthase (iNOS). In signal transduction, we also examined the NF-${\kappa}B$ (p65/p50), IKK, and I ${\kappa}B$, which are associated with the expression of iNOS gene using western blots. Results: In the present study, we found that UDCA effectively inhibited NO production in BV-2 microglial cell, and NF-${\kappa}B$ activation was reduced by suppressing IKK gene expression and by increasing the I${\kappa}B$ in cytosol comparing those to the positive control LPS. Conclusion: Taken together, these data suggested that UDCA may playa crucial role in inhibiting the NO production and the results imply that UDCA suppresses a cue signal of the microglial activation via stimulators, such as ${\beta}$-amyloid peptides which are known to stimulate microglia in AD pathogenesis.

Ghrelin Protects Spinal Cord Motoneurons Against Chronic Glutamate Excitotoxicity by Inhibiting Microglial Activation

  • Lee, Sung-Youb;Kim, Yu-Mi;Li, Endan;Park, Seung-Joon
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.1
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    • pp.43-48
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    • 2012
  • Glutamate excitotoxicity is emerging as a contributor to degeneration of spinal cord motoneurons in amyotrophic lateral sclerosis (ALS). Recently, we have reported that ghrelin protects motoneurons against chronic glutamate excitotoxicity through the activation of extracellular signal-regulated kinase 1/2 and phosphatidylinositol-3-kinase/Akt/glycogen synthase kinase-$3{\beta}$ pathways. Previous studies suggest that activated microglia actively participate in the pathogenesis of ALS motoneuron degeneration. However, it is still unknown whether ghrelin exerts its protective effect on motoneurons via inhibition of microglial activation. In this study, we investigate organotypic spinal cord cultures (OSCCs) exposed to threohydroxyaspartate (THA), as a model of excitotoxic motoneuron degeneration, to determine if ghrelin prevents microglial activation. Exposure of OSCCs to THA for 3 weeks produced typical motoneuron death, and treatment of ghrelin significantly attenuated THA-induced motoneuron loss, as previously reported. Ghrelin prevented THA-induced microglial activation in the spinal cord and the expression of pro-inflammatory cytokines tumor necrosis factor-${\alpha}$ and interleukin-$1{\beta}$. Our data indicate that ghrelin may act as a survival factor for motoneurons by functioning as a microglia-deactivating factor and suggest that ghrelin may have therapeutic potential for the treatment of ALS and other neurodegenerative disorders where inflammatory responses play a critical role.

The Effects of Hwanso-dan(Huanshaodan) Hot Water Extract & Ultra-fine Powder on Cytokine and Memory Deficit Model (환소단(還少丹)이 microglia 염증반응 cytokine과 건망증 생쥐모델에 미치는 영향)

  • Yoon, Jong-Cheon;Lee, Sang-Ryong;Jung, In-Chul
    • Journal of Oriental Neuropsychiatry
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    • v.20 no.1
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    • pp.43-57
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    • 2009
  • Objectives : This experiment was designed to investigate the effect of the Hwanso-dan hot water extract & ultra-fine powder on microglia and memory deficit model Methods : The effects of the Hwanso-dan hot water extract on expression of IL-l${\beta}$, IL-6, TNF-${\alpha}$ mRNA and production of IL-l${\beta}$, IL-6, TNF-${\alpha}$ in BV2 microglial cell line treated by lipopolysacchaide were investigated. The effects of the Hwanso-dan hot water extract & ultra-fine powder on the behavior of the memory deficit mice induced by scopolamine and uric acid & AChE in serum of the memory deficit mice induced by scopolamine were investigated. Results : 1. The Hwanso-dan hot water extract suppressed the expression of IL-l${\beta}$, IL-6, TNF-${\alpha}$ mRNA in BV2 microglial cell line treated by lipopolysacchaide. 2. The Hwanso-dan hot water extract suppressed the production of IL-l${\beta}$, IL-6, TNF-${\alpha}$ in BV2 microglial cell line. 3. The Hwanso-dan hot water extract & ultra-fine powder decreased uric acid and AChE significantly in the serum of the memory deficit mice induced by scopolamine. 4. The Hwanso-dan hot water extract & ultra-fine powder groups showed significantly inhibitory effect on the scopolamine${\sim}$induced impairment of memory in the experiment of Morris water maze. Conclusions : This experiment shows that the Hwanso-dan hot water extract & ultra-fine powder might be effective for the prevention and treatment of Memory deficit disease. Investigation into the clinical use of the Hwanso-dan hot water extract & ultra-fine powder for Alzheimer's disease is suggested for future research.

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Comparison of the Effects of Matrix Metalloproteinase Inhibitors on TNF-α Release from Activated Microglia and TNF-α Converting Enzyme Activity

  • Lee, Eun-Jung;Moon, Pyong-Gon;Baek, Moon-Chang;Kim, Hee-Sun
    • Biomolecules & Therapeutics
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    • v.22 no.5
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    • pp.414-419
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    • 2014
  • Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that regulate cell-matrix composition and are also involved in processing various bioactive molecules such as cell-surface receptors, chemokines, and cytokines. Our group recently reported that MMP-3, -8, and -9 are upregulated during microglial activation and play a role as proinflammatory mediators (Lee et al., 2010, 2014). In particular, we demonstrated that MMP-8 has tumor necrosis factor alpha (TNF-${\alpha}$)-converting enzyme (TACE) activity by cleaving the prodomain of TNF-${\alpha}$ and that inhibition of MMP-8 inhibits TACE activity. The present study was undertaken to compare the effect of MMP-8 inhibitor (M8I) with those of inhibitors of other MMPs, such as MMP-3 (NNGH) or MMP-9 (M9I), in their regulation of TNF-${\alpha}$ activity. We found that the MMP inhibitors suppressed TNF-${\alpha}$ secretion from lipopolysaccharide (LPS)-stimulated BV2 microglial cells in an order of efficacy: M8I>NNGH>M9I. In addition, MMP inhibitors suppressed the activity of recombinant TACE protein in the same efficacy order as that of TNF-${\alpha}$ inhibition (M8I>NNGH>M9I), proving a direct correlation between TACE activity and TNF-${\alpha}$ secretion. A subsequent pro-TNF-${\alpha}$ cleavage assay revealed that both MMP-3 and MMP-9 cleave a prodomain of TNF-${\alpha}$, suggesting that MMP-3 and MMP-9 also have TACE activity. However, the number and position of cleavage sites varied between MMP-3, -8, and -9. Collectively, the concurrent inhibition of MMP and TACE by NNGH, M8I, or M9I may contribute to their strong anti-inflammatory and neuroprotective effects.