• Title/Summary/Keyword: Microglia activation

검색결과 147건 처리시간 0.026초

신경세포 사멸과 미세아교세포활성화 억제 동시 가능 천연물질 탐색 연구 (A Screen for Dual-protection Molecules from a Natural Product Library against Neuronal Cell Death and Microglial Cell Activation)

  • 민주식;이동석
    • 생명과학회지
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    • 제25권6호
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    • pp.656-662
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    • 2015
  • 천연물을 기반으로 한 신약 개발은 일반적으로 오랜 기간 동안의 원료 약물로써 사용해 온 경험에 의한 다양한 임상적 결과의 축적과 이로 인한 안정성(stability)과 안전성(safety)의 확보 및 신약 개발 시간의 단축과 같은 이점을 가지고 있어, 천연물 유래 약물 연구는 꼭 필요한 실정이다. 다양한 신경질환에서 신경세포의 사멸과 미세아교세포의 과도한 활성화 즉 뇌염증이 관찰되며 이를 억제할 수 있는 물질에 대한 연구는 활발히 진행 중이지만, 현재까지 신경세포 사멸과 뇌염증을 동시에 억제하는 물질 개발 시도는 거의 없었다. 따라서, 본 연구에서는 천연물에서 추출한 물질로 총 240개로 구성된 라이브러리로부터 신경전달물질 중의 하나인 glutamate 과잉처리에 의한 산화적 스트레스 유도 신경세포(HT22) 사멸과 LPS에 의한 미세아교세포(BV2)의 과도한 활성화 즉 뇌염증의 표지 인자 중 하나인 NO의 생산량의 감소 효과가 동시에 나타나는 물질을 검출한 결과, 대황에서 추출한 Chrysophanol이 검출되었으며 더욱이 Chrysophanol이 신경세포와 미세아교세포 모두에서 glutamate와 LPS에 의해 각각 유도된 세포내 활성산소(ROS) 발생을 억제하는 것을 확인하였다. 앞으로 Chrysophanol에 대한 보다 깊은 연구를 통하여 산화적 스트레스에 의한 신경세포 사멸과 미세아교세포의 과잉 활성화에 따른 뇌염증의 발생을 동시에 억제하는 신경질환의 치료 및 예방 신약개발 후보 물질 가능성을 제시 하고자 한다.

Ginsenoside Rh2 attenuates microglial activation against toxoplasmic encephalitis via TLR4/NF-κB signaling pathway

  • Xu, Xiang;Jin, Lan;Jiang, Tong;Lu, Ying;Aosai, Fumie;Piao, Hu-Nan;Xu, Guang-Hua;Jin, Cheng-Hua;Jin, Xue-Jun;Ma, Juan;Piao, Lian-Xun
    • Journal of Ginseng Research
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    • 제44권5호
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    • pp.704-716
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    • 2020
  • Background: Ginsenoside Rh2 (GRh2) is a characterized component in red ginseng widely used in Korea and China. GRh2 exhibits a wide range of pharmacological activities, such as anti-inflammatory, antioxidant, and anticancer properties. However, its effects on Toxoplasma gondii (T. gondii) infection have not been clarified yet. Methods: The effect of GRh2 against T. gondii was assessed under in vitro and in vivo experiments. The BV2 cells were infected with tachyzoites of T. gondii RH strain, and the effects of GRh2 were evaluated by MTT assay, morphological observations, immunofluorescence staining, a trypan blue exclusion assay, reverse transcription PCR, and Western blot analyses. The in vivo experiment was conducted with BALB/c mice inoculated with lethal amounts of tachyzoites with or without GRh2 treatment. Results and conclusion: The GRh2 treatment significantly inhibited the proliferation of T. gondii under in vitro and in vivo studies. Furthermore, GRh2 blocked the activation of microglia and specifically decreased the release of inflammatory mediators in response to T. gondii infection through TLR4/NF-κB signaling pathway. In mice, GRh2 conferred modest protection from a lethal dose of T. gondii. After the treatment, the proliferation of tachyzoites in the peritoneal cavity of infected mice markedly decreased. Moreover, GRh2 also significantly decreased the T. gondii burden in mouse brain tissues. These findings indicate that GRh2 exhibits an antieT. gondii effect and inhibits the microglial activation through TLR4/NF-κB signaling pathway, providing the basic pharmacological basis for the development of new drugs to treat toxoplasmic encephalitis.

Ginsenoside Rh2 reduces depression in offspring of mice with maternal toxoplasma infection during pregnancy by inhibiting microglial activation via the HMGB1/TLR4/NF-κB signaling pathway

  • Xu, Xiang;Lu, Yu-Nan;Cheng, Jia-Hui;Lan, Hui-Wen;Lu, Jing-Mei;Jin, Guang-Nan;Xu, Guang-Hua;Jin, Cheng-Hua;Ma, Juan;Piao, Hu-Nan;Jin, Xuejun;Piao, Lian-Xun
    • Journal of Ginseng Research
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    • 제46권1호
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    • pp.62-70
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    • 2022
  • Background: Maternal Toxoplasma gondii (T. gondii) infection during pregnancy has been associated with various mental illnesses in the offspring. Ginsenoside Rh2 (GRh2) is a major bioactive compound obtained from ginseng that has an anti-T. gondii effect and attenuates microglial activation through toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway. GRh2 also alleviated tumor-associated or lipopolysaccharide-induced depression. However, the effects and potential mechanisms of GRh2 on depression-like behavior in mouse offspring caused by maternal T. gondii infection during pregnancy have not been investigated. Methods: We examined GRh2 effects on the depression-like behavior in mouse offspring, caused by maternal T. gondii infection during pregnancy, by measuring depression-like behaviors and assaying parameters at the neuronal and molecular level. Results: We showed that GRh2 significantly improved behavioral measures: sucrose consumption, forced swim time and tail suspended immobility time of their offspring. These corresponded with increased tissue concentrations of 5-hydroxytryptamine and dopamine, and attenuated indoleamine 2,3-dioxygenase or enhanced tyrosine hydroxylase expression in the prefrontal cortex. GRh2 ameliorated neuronal damage in the prefrontal cortex. Molecular docking results revealed that GRh2 binds strongly to both TLR4 and high mobility group box 1 (HMGB1). Conclusion: This study demonstrated that GRh2 ameliorated the depression-like behavior in mouse offspring of maternal T. gondii infection during pregnancy by attenuating the excessive activation of microglia and neuroinflammation through the HMGB1/TLR4/NF-κB signaling pathway. It suggests that GRh2 could be considered a potential therapy in preventing and treating psychiatric disorders in the offspring mice of mothers with prenatal exposure to T. gondii infection.

황련 추출물의 분획화 및 BV2 microglial cells에서 LPS에 의해 유도되는 nitric oxide 생성억제효과 검정 (Effects of subfractions of Coptidis Rhizoma extract on the nitric oxide production in LPS-stimulated BV2 microglial cells)

  • 정효원;박용기
    • 대한본초학회지
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    • 제22권2호
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    • pp.73-78
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    • 2007
  • Objectives : Uncontrolled activation of microglia may directly toxic to neurons by releasing various substances such as inflammatory cytokines, nitric oxide(NO), prostaglandin E2 and superoxide. In this study, the effects of the several subfractions isolated from Coptidis Rhizoma extract were investigated on NO production in LPS-stimulated BV2 microglial cells, Methods : Coptidis Rhizoma extract prepared with 80% methanol, and then fractionated with ethylacetate, chloroform, n-butanol and water. BV2 cells were pretreated four subfractions of Coptidis Rhizoma with various concentrations, and then stimulated with LPS. Cytotoxicity of each fraction was measured by MTT assay. NO production was determined in culture surpernatants by Griess reagent. Results : Ethylacetate, chloroform and butanol fractions of Coptidis Rhizoma extract significantly decreased LPS-induced NO production in BV2 cells as a dose-dependent manner without cytotoxicity. Ethylacetate fraction of Coptidis Rhizoma extract was most effective on inhibition of NO production in LPS-stimulated BV2 cells compared with other fractions. Conclusion : This data indicates that Ethylacetate fraction of Coptidis Rhizoma extract shows strong antiinflammatory effects through inhibition of LPS-induced microglial activation.

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Differential Effects of Minocycline on Caspase- and Calpain-dependent Cell Death After Oxidative Stress

  • Choi, Yu-Keum;Kim, Gap-Seok;Han, Byung-Hee
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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    • pp.67-67
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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, Huntingtons disease (HD), amyotrophic lateral sclerosis (ALS), traumatic brain injury, multiple sclerosis, and Parkinsons disease. When the activity of caspases was assessed using their fluorescent peptide substrates, 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 the cell viability as assessed by MTT assay as well as trypan blue staining. However, cleavage of alpha-spectrin and a cdk5 activator p35, which are known to be substrates for calpain, remained unchanged in the presence of minocycline, suggesting that minocycline did not block caspase-3-independent cell death or necrosis. Moreover, co-treatment with minocycline and a calpain inhibitor calpeptin synergistically inhibited hydrogen peroxide-induced cell death. These data suggest that minocycline directly inhibited apoptosis, but not necrosis, after oxidative insult in PC12 cells.

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대계와 실리비닌의 Mouse BV2 Microglial Cells에서 Lipopolysaccharide에 의해 유발된 염증반응에 대한 신경보호 효과 (Neuroprotective Effect of Cirsium japonicum and Silibinin on Lipopolysaccharide-induced Inflammation in BV2 Microglial Cells)

  • 여현수;김동우;전찬용;최유경;박종형
    • 대한한방내과학회지
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    • 제28권1호
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    • pp.166-175
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    • 2007
  • Objectives : This study was designed to evaluate the neuroprotective effect of Cirsium japonicum and Silibinin on lipopolysaccharide-induced inflammation in BV2 microglial cells. Methods : We studied on the neuroprotective effect of lipopolysaccharide-induced inflammation using MTS assay, western blot, and nitric oxide detection on mouse BV2 microglial cells. Results : Cirsium japonicum dose-dependently (50${\mu}g/ml$${\sim}$$250{\mu}g/ml$) inhibited nitrite production and iNOS expression in lipopolysaccharide-induced BV2 microglia and also significantly reduced lipopolysaccharide-induced COX-2 activation in western blot. Silibinin dose-dependently (10${\mu}M$${\sim}$$100{\mu}M$) inhibited nitrite production and iNOS expression in lipopolysaccharide-induced BV2 microglial cells. Silibinin also significantly reduced lipopolysaccharide-induced COX-2 activation in western blot. Conclusion : These effects of neuroprotection related to anti-inflammation suggest that Cirsium japonicum and Silibininmay be useful candidates for the development of a drug for related neurodegenerative diseases.

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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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    • 제22권5호
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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.

Olanzapine Attenuates Mechanical Allodynia in a Rat Model of Partial Sciatic Nerve Ligation

  • Fukuda, Taeko;Yamashita, Soichiro;Hisano, Setsuji;Tanaka, Makoto
    • The Korean Journal of Pain
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    • 제28권3호
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    • pp.185-192
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    • 2015
  • Background: Neuropathic pain is a global clinical problem; nevertheless, nerve injury treatment methods remain limited. Olanzapine has antinociceptive and anti-nueropathic properties; however, its preventive effects have not been assessed in nerve injury models. Methods: We prepared a partial sciatic nerve ligation (Seltzer model) or sham-operated model in male Sprague-Dawley rats under isoflurane anesthesia. In a pre-treatment study, we administered olanzapine (10 mg/kg) intraperitoneally 1 h before nerve ligation. In post-treatment and dose-dependent studies, we injected 3 different doses of olanzapine intraperitoneally 1 h after nerve ligation. Mechanical allodynia was measured before and 7 days after surgery. Immunohistochemical analysis using anti-Iba-1 antibody was used to assess the effect of olanzapine at the spinal level. Results: In the pre-treatment study, median withdrawal thresholds of the normal saline groups were significantly lower than those of the sham-operated groups; however, those of the olanzapine (10 mg/kg) and sham-operated groups were not different. In the post-treatment and dose-dependent studies, the median withdrawal thresholds of the olanzapine (2.5 mg/kg) and normal saline groups were not different; however, those of the olanzapine (10 and 50 mg/kg) groups were significantly higher than those of the normal saline groups. Olanzapine did not have a significant effect on the density of Iba-1 staining. Conclusions: Olanzapine attenuated mechanical allodynia dose-dependently in the Seltzer model. This anti-allodynic effect of olanzapine was observed even when injected 1 h after nerve ligation. This effect of olanzapine appeared to be unrelated to microglia activation in the ipsilateral dorsal horn of the lumbar spinal cord.

지질다당류로 유발한 염증성 뇌손상 동물모델에 대한 황금작약탕의 억제효과 연구 (Anti-neuroinflammatory Effects of Hwanggeumjakyak-tang on Lipopolysaccharide-induced Brain Injury Model in vivo and in vitro)

  • 김종규;임지성;안성후;송용선
    • 한방재활의학과학회지
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    • 제31권4호
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    • pp.1-11
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    • 2021
  • Objectives Hwanggeumjakyak-tang (HJT) has traditionally been used to treat gastrointestinal inflammatory diseases; however, its protective effects against neuronal inflammation are still undiscovered. Methods We investigated the anti-neuroinflammatory effects of HJT water extract on lipopolysaccharide (LPS)-stimulated BV2 mouse microglia cells. BV2 cells were treated with LPS (1 ㎍/mL) 1 hour prior to the addition of HJT. We measured cell viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and nitrite production using the Griess assay. We performed a reverse transcription-polymerase chain reaction assay to measure messenger RNA expression of inflammatory cytokines including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. Western blot analysis was performed to determine protein expression of mitogen-activated protein kinases (MAPKs) and inhibitor of nuclear factor kappa B (NF-κB)α. Results HJT inhibited excessive nitrite release in LPS-stimulated BV2 cells and also significantly inhibited inflammatory cytokines such as IL-1β, IL-6, and TNF-α in LPS-stimulated BV2 cells. Moreover, HJT significantly suppressed LPS-induced MAPK and NF-κB activation and inhibited the elevation of IL-1β, IL-6, and TNF-α in the brain of LPS-injected mice. Conclusions Our study highlights the anti-neuroinflammatory effects of HJT via MAPK and NF-κB deactivation.

주요우울증에서 스트레스, 염증반응, 신경조직발생 (Stress, Inflammation and Neurogenesis in Major Depression)

  • 김용구
    • 생물정신의학
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    • 제18권4호
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    • pp.169-175
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    • 2011
  • Stress, a risk factor of major depression induces cytokine mediated inflammation and decreased neurogenesis. In patients with major depression, significant increases of pro-inflammatory cytokines have been consistently reported. The pro-inflammatory cytokines can stimulate the hypothalamic-pituitary-adrenal (HPA) axis to release glucocorticoids. In the brain, microglia and play a role of immune activation in response to stress. Increased pro-inflammatory cytokine play a role in restricting neurogenesis in the brain. Although neurogenesis may not be essential for the development of depression, it may be required for clinically effective antidepressant treatment. Hence, stimulation of neurogenesis is regarded as a promising strategy for new antidepressant targets. This review introduces changes in neurotransmitter, cytokine and neurogenesis in major depression and explores the possible relationship between pro-inflammatory cytokines and neurogenesis related to stress in major depression.