• Title/Summary/Keyword: inflammatory response

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Induction of Functional Changes of Dendritic Cells by Silica Nanoparticles

  • Kang, Kyeong-Ah;Lim, Jong-Seok
    • IMMUNE NETWORK
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    • v.12 no.3
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    • pp.104-112
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    • 2012
  • Silica is one of the most abundant compounds found in nature. Immoderate exposure to crystalline silica has been linked to pulmonary disease and crystalline silica has been classified as a Group I carcinogen. Ultrafine (diameter <100 nm) silica particles may have different toxicological properties compared to larger particles. We evaluated the effect of ultrafine silica nanoparticles on mouse bone marrow-derived dendritic cells (BMDC) and murine dendritic cell line, DC2.4. The exposure of dendritic cells (DCs) to ultrafine silica nanoparticles showed a decrease in cell viability and an induction of cell death in size- and concentration-dependent manners. In addition, in order to examine the phenotypic changes of DCs following co-culture with silica nanoparticles, we added each sized-silica nanoparticle along with GM-CSF and IL-4 during and after DC differentiation. Expression of CD11c, a typical DC marker, and multiple surface molecules such as CD54, CD80, CD86, MHC class II, was changed by silica nanoparticles in a size-dependent manner. We also found that silica nanoparticles affect inflammatory response in DCs in vitro and in vivo. Finally, we found that p38 and NF-${\kappa}B$ activation may be critical for the inflammatory response by silica nanoparticles. Our data demonstrate that ultrafine silica nanoparticles have cytotoxic effects on dendritic cells and immune modulation effects in vitro and in vivo.

Nucleotide-Binding Domain and Leucine-Rich Repeat Containing Receptor (NLR) and its Signaling Pathway

  • Park, Sangwook;Gwon, Sun-Yeong;Rhee, Ki-Jong
    • Biomedical Science Letters
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    • v.19 no.3
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    • pp.173-179
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    • 2013
  • Since the identification and characterization of toll-like receptors (TLR) in Drosophila, numerous scientific studies have examined the role of TLRs in host innate immunity. Recent studies have suggested a convergence of the nuclear factor kappa B (NF-${\kappa}B$) signaling and cytokine production regulated by the cytosolic elicitor known as NLRs (nucleotide-binding domain and leucine-rich repeat containing domain receptors) as a key modulator in inflammatory diseases. Among the NLRs, NOD1 and NOD2 have been intensively investigated for its role in inflammatory bowel disease (IBD). On the other hand, NLRs such as NLRP3, NLRP1, and NLRC4 (also known as IPAF) have been identified to form the inflammasome to activate downstream signaling molecules in response to pathogenic microbes. There is evidence to suggest that substantial crosstalk exists for the TLR and NLR signaling pathway in response to pathogen associated molecular pattern (PAMP). However, the substrate and the mechanistic role of NLRs are largely unknown in innate immune response. Understanding the signaling mechanisms by which NLRs recognize PAMP and other danger signals will shed light on elucidating the pathogenesis of various human inflammatory diseases such as IBD.

Reversal of Immunogenicity in Pediatric Inflammatory Bowel Disease Patients Receiving Anti-Tumor Necrosis Factor Medications

  • Kang, Elise;Khalili, Ali;Splawski, Judy;Sferra, Thomas J.;Moses, Jonathan
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.21 no.4
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    • pp.329-335
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    • 2018
  • Loss of response to anti-tumor necrosis factor (anti-TNF) agents in the treatment of inflammatory bowel disease (IBD) is a major consideration to maintain sustained response. Reversal of immunogenicity can re-establish response and increase the durability of these agents. Strategies to reverse immunogenicity include dose-intensification and/or the addition of an immunomodulator. However, there is a relative paucity of data on the efficacy of such interventions in pediatric IBD patients. Available reports have not strictly utilized homogenous mobility shift assay, which reports on anti-drug antibodies even in the presence of detectable drug, whereas prior studies have been confounded by the use of drug sensitive assays. We report four pediatric inflammatory bowel disease patients with successful reversal of immunogenicity on an anti-TNF agent using dose intensification and/or addition of an immunomodulator.

Silencing YY1 Alleviates Ox-LDL-Induced Inflammation and Lipid Accumulation in Macrophages through Regulation of PCSK9/ LDLR Signaling

  • Zhengyao Qian;Jianping Zhao
    • Journal of Microbiology and Biotechnology
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    • v.32 no.11
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    • pp.1406-1415
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    • 2022
  • The formation of macrophage foam cells stimulated by oxidized low-density lipoprotein (ox-LDL) is deemed an important cause of atherosclerosis. Transcription factor Yin Yang 1 (YY1), which is a universally expressed multifunctional protein, is closely related to cell metabolism disorders such as lipid metabolism, sugar metabolism, and bile acid metabolism. However, whether YY1 is involved in macrophage inflammation and lipid accumulation still remains unknown. After mouse macrophage cell line RAW264.7 cells were induced by ox-LDL, YY1 and proprotein convertase subtilisin/kexin type 9 (PCSK9) expressions were found to be increased while low-density lipoprotein receptor (LDLR) expression was lowly expressed. Subsequently, through reverse transcription-quantitative polymerase chain reaction (RT-qPCR), Western blot analysis, Oil Red O staining and cholesterol quantification, it turned out that silencing of YY1 attenuated the inflammatory response and lipid accumulation in RAW264.7 cells caused by ox-LDL. Moreover, results from the JASPAR database, chromatin immunoprecipitation (ChIP) assay, luciferase reporter assay and Western blot analysis suggested that YY1 activated PCSK9 by binding to PCSK9 promoter and modulated the expression of LDLR in the downstream of PCSK9. In addition, the results of functional experiments demonstrated that the inhibitory effects of YY1 interference on ox-LDL-mediated macrophage inflammation and lipid accumulation were reversed by PCSK9 overexpression. To sum up, YY1 depletion inhibited its activation of PCSK9, thereby reducing cellular inflammatory response, cholesterol homeostasis imbalance, and lipid accumulation caused by ox-LDL.

Effect of Dipsaci Radix Water Extract on LPS-induced Inflammatory Response in RAW264.7 Mouse Macrophages (속단(續斷)의 RAW264.7 세포에서 LPS에 의해 유도되는 염증반응에 대한 효과)

  • Min, Ji-Young;Park, Yong-Ki
    • The Korea Journal of Herbology
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    • v.24 no.4
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    • pp.189-195
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    • 2009
  • Objectives : In this study, the effect of Dipsaci Radix(DR, Dipsacus asperoides C.Y. Cheng et T. M. Ai) water extract on LPS-induced inflammatory response in RAW264.7 cells were investigated. Methods : Dried roots of DR was extracted with water for 3 h(DR-W extract). RAW264.7 cells, a mouse macrophage line, were incubated with different concentrations of DR-W extract for 30 min and then stimulated with LPS at indicated times. Cell toxicity was determined by MTT assay. The concentrations of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) were measured by Griess assay and enzyme immunoassay (EIA), respectively. The expression of inducible nitric oxide synthease (iNOS) and cyclooxyganase (COX)-2 mRNA and protein was determined by RT-PCR and Western blot, respectively. Results : DR-W extract was significantly inhibited LPS-induced productions of NO and PGE2 in RAW264.7 cells. DR-W extract was not suppressed the expressions of iNOS mRNA and protein in LPS-stimulated RAW264.7 cells. Conclusions : This study suggests that DR-W extract can attenuate inflammatory response via inhibition of the NO and PGE2 production in activated macrophages.

Gut Microbiota in Inflammatory Bowel Disease

  • Shim, Jung Ok
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.16 no.1
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    • pp.17-21
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    • 2013
  • The gut mucosal barrier plays an important role in maintaining a delicate immune homeostasis. The pathogenesis of inflammatory bowel disease (IBD) is considered to involve a defective mucosal immunity along with a genetic predisposition. Recent views have suggested an excessive response to components of the gut microbiota in IBD. A condition of "dysbiosis", with alterations of the gut microbial composition, has been observed in patients with IBD. In this article, the author review recent studies of gut microbiota in IBD, particularly the importance of the gut microbiota in the pathogenesis of pediatric IBD.

Study on the Anti-Inflammatory Activity and Mechanism of Medicinal Plants Used in the Treatment of Arthritis (관절염 치료에 사용되는 한약재들의 항 염증 활성과 기전에 관한 연구)

  • Kim, Yoo-Hyun;Park, Ho
    • Korean Journal of Clinical Laboratory Science
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    • v.48 no.3
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    • pp.176-182
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    • 2016
  • When inflammatory reaction is in progress, the macrophages release inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and product inflammatory mediators, including inducible nitric oxide synthase (iNOS) and prostaglandin E2 (PGE2). We conducted this study to evaluate the anti-inflammatory efficacy on each water extract of Acanthopanacis cortex, Achyranthes radix, and Eucommiae cortex, and to investigate whether they inhibit the expression of pro-inflammatory cytokine. Acanthopanacis cortex, Achyranthes radix, and Eucommiae cortex were extracted with water and freeze-dried. Acanthoside D, 20-hydroxyecdysone, and pinoresinol diglucoside as an index material were analyzed by high-performance liquid chromatography (HPLC) to ensure that the components of each extracts were extracted well. RAW 264.7 cell line, stimulated with lipopolysaccharide (LPS) to cause an inflammatory response, was treated with each water extract at various concentrations to determine the anti-inflammatory efficacy. Then, the anti-inflammatory efficacy was confirmed by a nitric oxide (NO) assay, and the mRNA expression levels of pro-inflammatory cytokines were measured by real time PCR. As a result, the indicator materials were detected from each extract, and Acanthopanacis cortex water extract (ACWE) and Achyranthes radix water extract (ARWE) were shown to have a high activity than Eucommiae cortex water extract (ECWE) in NO assay. In Korea, traditionally it prescribed a combination of medicinal herbs. This study confirmed the anti-inflammatory response of these medicinal plants in arthritis and its synergistic effect when used in combination with western medicine.

The Anti-inflammatory Mechanism of Protaetia brevitarsis Lewis via Suppression the Activation of NF-κB and Caspase-1 in LPS-stimulated RAW264.7 Cells

  • Myung, Noh-Yil;Ahn, Eun-Mi;Kim, Su-Jin
    • Biomedical Science Letters
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    • v.26 no.4
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    • pp.267-274
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    • 2020
  • The larva of Protaetia brevitarsis Lewis (P. brevitarsis), edible insect, is traditionally consumed as alternative source of nutrients and has various health benefits. However, the exact pharmaceutical effects of P. brevitarsis on inflammatory response are still not well understood. Thus, we investigated the anti-inflammatory effects and mechanisms of P. brevitarsis in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. We investigated the effects of P. brevitarsis on the expression levels of inflammatory-related genes, including inflammatory cytokines, prostaglandin E2 (PGE2), cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) in LPS-stimulated RAW264.7 cells. To understand the anti-inflammatory mechanism of P. brevitarsis, we explored the regulatory effect of P. brevitarsis on nuclear factor (NF)-κB and caspase-1 activation. The findings of this study demonstrated that P. brevitarsis inhibits the LPS-induced inflammatory cytokine and PGE2 levels, as well as COX-2 and iNOS expression. Moreover, we confirmed that the anti-inflammatory effect of P. brevitarsis occurs via suppression of the activation of NF-κB and caspase-1. Conclusively, these findings provide experimental evidence that P. brevitarsis may be useful candidate for the treatment of inflammatory-related diseases.

Human umbilical cord mesenchymal stem cell-derived mitochondria (PN-101) attenuate LPS-induced inflammatory responses by inhibiting NFκB signaling pathway

  • Yu, Shin-Hye;Kim, Soomin;Kim, Yujin;Lee, Seo-Eun;Park, Jong Hyeok;Cho, Gayoung;Ha, Jong-Cheon;Jung, Hahnsun;Lim, Sang-Min;Han, Kyuboem;Lee, Hong Kyu;Kang, Young Cheol;Kim, Chun-Hyung
    • BMB Reports
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    • v.55 no.3
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    • pp.136-141
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    • 2022
  • Inflammation is one of the body's natural responses to injury and illness as part of the healing process. However, persistent inflammation can lead to chronic inflammatory diseases and multi-organ failure. Altered mitochondrial function has been implicated in several acute and chronic inflammatory diseases by inducing an abnormal inflammatory response. Therefore, treating inflammatory diseases by recovering mitochondrial function may be a potential therapeutic approach. Recently, mitochondrial transplantation has been proven to be beneficial in hyperinflammatory animal models. However, it is unclear how mitochondrial transplantation attenuates inflammatory responses induced by external stimuli. Here, we isolated mitochondria from umbilical cord-derived mesenchymal stem cells, referred as to PN-101. We found that PN-101 could significantly reduce LPS-induced mortality in mice. In addition, in phorbol 12-myristate 13-acetate (PMA)-treated THP-1 macrophages, PN-101 attenuated LPS-induced increase production of pro-inflammatory cytokines. Furthermore, the anti-inflammatory effect of PN-101 was mediated by blockade of phosphorylation, nuclear translocation, and trans-activity of NFκB. Taken together, our results demonstrate that PN-101 has therapeutic potential to attenuate pathological inflammatory responses.