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Kunst C, Schmid S, Michalski M, Tümen D, Buttenschön J, Müller M, Gülow K. The Influence of Gut Microbiota on Oxidative Stress and the Immune System. Biomedicines 2023; 11:biomedicines11051388. [PMID: 37239059 DOI: 10.3390/biomedicines11051388] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
The human gastrointestinal tract is home to a complex microbial community that plays an important role in the general well-being of the entire organism. The gut microbiota generates a variety of metabolites and thereby regulates many biological processes, such as the regulation of the immune system. In the gut, bacteria are in direct contact with the host. The major challenge here is to prevent unwanted inflammatory reactions on one hand and on the other hand to ensure that the immune system can be activated when pathogens invade. Here the REDOX equilibrium is of utmost importance. This REDOX equilibrium is controlled by the microbiota either directly or indirectly via bacterial-derived metabolites. A balanced microbiome sorts for a stable REDOX balance, whereas dysbiosis destabilizes this equilibrium. An imbalanced REDOX status directly affects the immune system by disrupting intracellular signaling and promoting inflammatory responses. Here we (i) focus on the most common reactive oxygen species (ROS) and (ii) define the transition from a balanced REDOX state to oxidative stress. Further, we (iii) describe the role of ROS in regulating the immune system and inflammatory responses. Thereafter, we (iv) examine the influence of microbiota on REDOX homeostasis and how shifts in pro- and anti-oxidative cellular conditions can suppress or promote immune responses or inflammation.
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Affiliation(s)
- Claudia Kunst
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology, Rheumatology and Infectious Diseases, University Hospital Regensburg, 93053 Regensburg, Bavaria, Germany
| | - Stephan Schmid
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology, Rheumatology and Infectious Diseases, University Hospital Regensburg, 93053 Regensburg, Bavaria, Germany
| | - Marlen Michalski
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology, Rheumatology and Infectious Diseases, University Hospital Regensburg, 93053 Regensburg, Bavaria, Germany
| | - Deniz Tümen
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology, Rheumatology and Infectious Diseases, University Hospital Regensburg, 93053 Regensburg, Bavaria, Germany
| | - Jonas Buttenschön
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology, Rheumatology and Infectious Diseases, University Hospital Regensburg, 93053 Regensburg, Bavaria, Germany
| | - Martina Müller
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology, Rheumatology and Infectious Diseases, University Hospital Regensburg, 93053 Regensburg, Bavaria, Germany
| | - Karsten Gülow
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology, Rheumatology and Infectious Diseases, University Hospital Regensburg, 93053 Regensburg, Bavaria, Germany
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Ávila TV, Menezes-Garcia Z, do Nascimento Arifa RD, Soriani FM, Machado ADMV, Teixeira MM, Fagundes CT, Souza DG. Mitochondrial DNA as a Possible Ligand for TLR9 in Irinotecan-induced Small Intestinal Mucositis. Immunol Invest 2022; 51:1756-1771. [PMID: 35152824 DOI: 10.1080/08820139.2022.2026379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Cancer chemotherapy and radiotherapy may result in mucositis characterized by stem cell damage and inflammation in the gastrointestinal tract. The molecular mechanisms underlying this pathology remain unknown. Based on the assumption that mitochondrial CPG-DNA (mtDNA) released and sensed by TLR9 could underlie mucositis pathology, we analyzed the mtDNA levels in sera as well as inflammatory and disease parameters in the small intestine from wild-type (WT) and TLR9-deficient mice (TLR9-/-) in an experimental model of intestinal mucositis induced by irinotecan. Additionally, we verified the ability of WT and TLR9-/- macrophages to respond to CpG-DNA in vitro. WT mice injected with irinotecan presented a progressive increase in mtDNA in the serum along with increased hematocrit, shortening of small intestine length, reduction of intestinal villus:crypt ratio and increased influx of neutrophils, which were followed by higher expression of Nlrp3 and Casp1 mRNA and increased IL-1β levels in the ileum when compared to vehicle-injected mice. TLR9-deficient mice were protected in all these parameters when compared to WT mice. Furthermore, TLR9 was required for the production of IL-1β and NO after macrophage stimulation with CpG-DNA. Overall, our findings show that the amount of circulating free CpG-DNA is increased upon chemotherapy and that TLR9 activation is important for NLRP3 inflammasome transcription and further IL-1β release, playing a central role in the development of irinotecan-induced intestinal mucositis. We suggest that TLR9 antagonism may be a new therapeutic strategy for limiting irinotecan-induced intestinal inflammation.
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Affiliation(s)
- Thiago Vinicius Ávila
- Department of Pharmacology, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Zélia Menezes-Garcia
- Department of Microbiology and Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Raquel Duque do Nascimento Arifa
- Laboratório de Interação Microorganismo-Hospedeiro, Department de Microbiology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | - Mauro Martins Teixeira
- Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Caio Tavares Fagundes
- Laboratório de Interação Microorganismo-Hospedeiro, Department de Microbiology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Daniele G Souza
- Laboratório de Interação Microorganismo-Hospedeiro, Department de Microbiology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Sipos F, Bohusné Barta B, Simon Á, Nagy L, Dankó T, Raffay RE, Petővári G, Zsiros V, Wichmann B, Sebestyén A, Műzes G. Survival of HT29 Cancer Cells Is Affected by IGF1R Inhibition via Modulation of Self-DNA-Triggered TLR9 Signaling and the Autophagy Response. Pathol Oncol Res 2022; 28:1610322. [PMID: 35651701 PMCID: PMC9148969 DOI: 10.3389/pore.2022.1610322] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/27/2022] [Indexed: 02/05/2023]
Abstract
Purpose: In HT29 colon cancer cells, a close interplay between self-DNA-induced TLR9 signaling and autophagy response was found, with remarkable effects on cell survival and differentiation. IGF1R activation drives the development and malignant progression of colorectal cancer. IGF1R inhibition displays a controversial effect on autophagy. The interrelated roles of IGF1R inhibition and TLR9/autophagy signaling in HT29 cancer cells have not yet been clarified. In our study, we aimed to investigate the complex interplay of IGF1R inhibition and TLR9/autophagy signaling in HT29 cells. Methods: HT29 cells were incubated with tumor-originated self-DNA with or without inhibitors of IGF1R (picropodophyllin), autophagy (chloroquine), and TLR9 (ODN2088), respectively. Cell proliferation and metabolic activity measurements, direct cell counting, NanoString and Taqman gene expression analyses, immunocytochemistry, WES Simple Western blot, and transmission electron microscopy investigations were performed. Results: The concomitant use of tumor-derived self-DNA and IGF1R inhibitors displays anti-proliferative potential, which can be reversed by parallel TLR9 signaling inhibition. The distinct effects of picropodophyllin, ODN2088, and chloroquine per se or in combination on HT29 cell proliferation and autophagy suggest that either the IGF1R-associated or non-associated autophagy machinery is "Janus-faced" regarding its actions on cell proliferation. Autophagy, induced by different combinations of self-DNA and inhibitors is not sufficient to rescue HT29 cells from death but results in the survival of some CD133-positive stem-like HT29 cells. Conclusion: The creation of new types of combined IGF1R, autophagy, and/or TLR9 signaling inhibitors would play a significant role in the development of more personalized anti-tumor therapies for colorectal cancer.
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Affiliation(s)
- Ferenc Sipos
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
- *Correspondence: Ferenc Sipos,
| | - Bettina Bohusné Barta
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
| | - Ágnes Simon
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
| | - Lőrinc Nagy
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
| | - Titanilla Dankó
- Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Regina Eszter Raffay
- Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Gábor Petővári
- Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Viktória Zsiros
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | | | - Anna Sebestyén
- Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Györgyi Műzes
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
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The Short-Chain Fatty Acids Propionate and Butyrate Augment Adherent-Invasive Escherichia coli Virulence but Repress Inflammation in a Human Intestinal Enteroid Model of Infection. Microbiol Spectr 2021; 9:e0136921. [PMID: 34612688 PMCID: PMC8510176 DOI: 10.1128/spectrum.01369-21] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Short-chain fatty acids (SCFAs), which consist of six or fewer carbons, are fermentation products of the bacterial community that inhabits the intestine. Due to an immunosuppressive effect on intestinal tissue, they have been touted as a therapeutic for inflammatory conditions of the bowel. Here, we study the impact of acetate, propionate, and butyrate, the three most abundant SCFAs in the intestine, on gene expression in the intestinal pathobiont adherent-invasive Escherichia coli. We pair this with adherence, invasion, and inflammation in Caco-2 and human intestinal enteroid (HIE)-derived monolayer models of the intestinal epithelium. We report that propionate and butyrate upregulate transcription of adherent-invasive Escherichia coli (AIEC) flagellar synthesis genes and decrease expression of capsule assembly and transport genes. These changes are predicted to augment AIEC invasiveness. In fact, SCFA supplementation increases AIEC adherence to and invasion of the Caco-2 monolayer but has no effect on these parameters in the HIE model. We attribute this to the anti-inflammatory effect of propionate and butyrate on HIEs but not on Caco-2 cells. We conclude that the potential of SCFAs to increase the virulence of intestinal pathogens should be considered in their use as anti-inflammatory agents. IMPORTANCE The human terminal ileum and colon are colonized by a community of microbes known as the microbiota. Short-chain fatty acids (SCFAs) excreted by bacterial members of the microbiota define the intestinal environment. These constitute an important line of communication within the microbiota and between the microbiota and the host epithelium. In inflammatory conditions of the bowel, SCFAs are often low and there is a preponderance of a conditionally virulent bacterium termed adherent-invasive Escherichia coli (AIEC). A connection between SCFA abundance and AIEC has been suggested. Here, we study AIEC in monoculture and in coculture with human intestinal enteroid-derived monolayers and show that the SCFAs propionate and butyrate increase expression of AIEC virulence genes while concurrently bolstering the intestinal epithelial barrier and reducing intestinal inflammation. While these SCFAs have been promoted as a therapy for inflammatory bowel conditions, our findings demonstrate that their effect on bacterial virulence must be considered.
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Shigemori S, Namai F, Ogita T, Sato T, Shimosato T. Oral priming with oligodeoxynucleotide particles from Lactobacillus rhamnosus GG attenuates symptoms of dextran sodium sulfate-induced acute colitis in mice. Anim Sci J 2020; 91:e13468. [PMID: 33025687 DOI: 10.1111/asj.13468] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/30/2020] [Accepted: 09/10/2020] [Indexed: 12/11/2022]
Abstract
Here, we investigated the effect of prophylactic oral treatment with carbonate apatite-based particles (ID35caps) containing Lactobacillus rhamnosus GG-derived immunostimulatory oligodeoxynucleotides (ID35) when used in mice with acute colitis. Mice were administered orally with control particles (carbonate apatite particles, Caps), ID35, or ID35caps for 2 days, and then were given free access to drinking water containing 3% (w/v) dextran sodium sulfate (DSS) for 5 days (Days 0-5) to induce acute colitis. Body weight change, fecal bleeding, and stool consistency were monitored and scored as a disease activity index (DAI) to assess symptoms of colitis. On Day 10, animals were euthanized and the colon length was measured to evaluate inflammatory tissue injury. Prophylactic oral treatment with ID35caps significantly suppressed DSS-induced elevation of the DAI score and shortening of the colon compared to the respective parameters in DSS-exposed mice treated with Cap or ID35. We conclude that oral priming with ID35caps attenuates symptoms and inflammatory colonic injury in a mouse model of DSS-induced acute colitis. This finding suggests that ID35caps may be a new oral agent for preventing intestinal inflammation.
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Affiliation(s)
- Suguru Shigemori
- Department of Biomolecular Innovation, Institute for Biomedical Sciences, Shinshu University, Kamiina, Japan
| | - Fu Namai
- Department of Biomolecular Innovation, Institute for Biomedical Sciences, Shinshu University, Kamiina, Japan
| | - Tasuku Ogita
- Department of Biomolecular Innovation, Institute for Biomedical Sciences, Shinshu University, Kamiina, Japan
| | - Takashi Sato
- Department of Biomolecular Innovation, Institute for Biomedical Sciences, Shinshu University, Kamiina, Japan
| | - Takeshi Shimosato
- Department of Biomolecular Innovation, Institute for Biomedical Sciences, Shinshu University, Kamiina, Japan
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Kiwifruit drives human microbiota-derived DNA to stimulate IL-7 secretion in intestinal epithelial cells. J Funct Foods 2020. [DOI: 10.1016/j.jff.2020.103882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Zhang S, Jia X, Zhang Q, Zhang L, Yang J, Hu C, Shi J, Jiang X, Lu J, Shen H. Neutrophil extracellular traps activate lung fibroblast to induce polymyositis-related interstitial lung diseases via TLR9-miR-7-Smad2 pathway. J Cell Mol Med 2019; 24:1658-1669. [PMID: 31821687 PMCID: PMC6991674 DOI: 10.1111/jcmm.14858] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 06/18/2019] [Accepted: 07/23/2019] [Indexed: 12/13/2022] Open
Abstract
Excessive neutrophil extracellular trap (NET) formation may contribute to polymyositis (PM)‐associated interstitial lung diseases (ILD), but the underlying mechanism is not fully revealed. In this study, we found that NET accelerated the progression of ILD and promoted pulmonary fibrosis (PF) in vivo. miR‐7 expression was down‐regulated in lung tissue of PM group than control group, and NETs further decreased miR‐7 expression. TLR9 and Smad2 were up‐regulated in lung tissue of PM group than control group, and NETs further increased TLR9 and Smad2 expressions. In vitro experiments showed that PMA‐treated NETs accelerated the proliferation of LF and their differentiation into myofibroblast (MF), whereas DNase I decreased the promotion effect of NETs. Neutrophil extracellular trap components myeloperoxidase (MPO) and histone 3 also promoted the proliferation and differentiation of LF. In addition, we demonstrated that TLR9 involved in the regulation of NETs on LF proliferation and differentiation, and confirmed the interaction between miR‐7 and Smad2 in LF. Finally, miR‐7‐Smad2 pathway was confirmed to be involved in the regulation of TLR9 on LF proliferation and differentiation. Therefore, NETs promote PM‐related ILD, and TLR9‐miR‐7‐Smad2 signalling pathway is involved in the proliferation of LFs and their differentiation into MFs.
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Affiliation(s)
- Sigong Zhang
- Department of Rheumatology, Lanzhou University Second Hospital, Lanzhou, China
| | - Xueqin Jia
- Department of Rheumatology, Lanzhou University Second Hospital, Lanzhou, China
| | - Qiuyue Zhang
- The Second Clinical Medical College, Lanzhou University, Lanzhou, China
| | - Li Zhang
- Department of Rheumatology, Lanzhou University Second Hospital, Lanzhou, China
| | - Jing Yang
- Department of Rheumatology, Lanzhou University Second Hospital, Lanzhou, China
| | - Caihong Hu
- Department of Endocrinology, Lanzhou University Second Hospital, Lanzhou, China
| | - Junnian Shi
- Department of Pneumology, Lanzhou University Second Hospital, Lanzhou, China
| | - Xiao Jiang
- The Second Clinical Medical College, Lanzhou University, Lanzhou, China
| | - Jinyue Lu
- Department of Rheumatology, Lanzhou University Second Hospital, Lanzhou, China
| | - Haili Shen
- Department of Rheumatology, Lanzhou University Second Hospital, Lanzhou, China
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Han SJ, Li H, Kim M, D’Agati V, Lee HT. Intestinal Toll-like receptor 9 deficiency leads to Paneth cell hyperplasia and exacerbates kidney, intestine, and liver injury after ischemia/reperfusion injury. Kidney Int 2019; 95:859-879. [DOI: 10.1016/j.kint.2018.10.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 10/09/2018] [Accepted: 10/24/2018] [Indexed: 01/02/2023]
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Thomalla M, Schmid A, Neumann E, Pfefferle PI, Müller-Ladner U, Schäffler A, Karrasch T. Evidence of an anti-inflammatory toll-like receptor 9 (TLR 9) pathway in adipocytes. J Endocrinol 2019; 240:325-343. [PMID: 30508414 DOI: 10.1530/joe-18-0326] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 11/30/2018] [Indexed: 12/17/2022]
Abstract
Adipocytes express various pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) and actively participate in anti-bacterial and anti-viral host defence. Obesity is associated with adipose tissue PRR expression. The potential role of Toll-like receptor 9 (TLR9) in adipocytes has not yet been investigated. Here, we evaluated TLR9 expression during adipocyte differentiation (AD) of 3T3-L1 adipocytes, in primary murine adipocytes and in different murine and human adipose tissue depots by real-time PCR, immunocytochemistry and immunohistochemistry. TLR9 expression was inhibited using specific siRNA-mediated knockdown, and TLR9 signaling was induced using specific class A, B and C agonistic CpG-oligodeoxynucleotide (ODN) treatment vs ODN controls in 3T3-L1 adipocytes and in primary murine adipocytes from Tlr9wt/wt vs Tlr9-/- mice. We found that TLR9 gene expression is induced during AD and that TLR9 protein is expressed in murine gonadal and human visceral adipocytes. AD depends on intact TLR9 expression. Tlr9-/- mice demonstrate significantly reduced adiponectin serum levels, while siRNA-mediated TLR9 knockdown led to reduced adiponectin mRNA expression in adipocytes. TLR9 ligands (CpG-ODNs) inhibit pro-inflammatory resistin secretion in mature 3T3-L1 adipocytes. Tlr9-/- as compared to Tlr9wt/wt adipocytes exhibit increased resistin and MCP1 secretion and reduced adiponectin secretion into cell culture supernatants, while TLR9 ligands (ODNs) show differential effects in Tlr9-/- vs Tlr9wt/wt primary murine adipocytes. TLR9 expression is significantly increased in visceral compared to subcutaneous adipose tissue depots in non-diabetic obese patients and correlates with systemic resistin levels in a compartment-specific manner. Thus, adipocytic TLR9 is a putative, new protective factor during (obesity-associated) adipose tissue inflammation.
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Affiliation(s)
- Miriam Thomalla
- Department of Internal Medicine III, Giessen University Hospital, Giessen, Germany
| | - Andreas Schmid
- Department of Internal Medicine III, Giessen University Hospital, Giessen, Germany
| | - Elena Neumann
- Department of Rheumatology and Clinical Immunology, University of Giessen and Kerckhoff Clinic, Bad Nauheim, Germany
| | - Petra Ina Pfefferle
- Comprehensive Biomaterial Bank Marburg (CBBMR), Philipps-University of Marburg, Marburg, Germany
| | - Ulf Müller-Ladner
- Department of Rheumatology and Clinical Immunology, University of Giessen and Kerckhoff Clinic, Bad Nauheim, Germany
| | - Andreas Schäffler
- Department of Internal Medicine III, Giessen University Hospital, Giessen, Germany
| | - Thomas Karrasch
- Department of Internal Medicine III, Giessen University Hospital, Giessen, Germany
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Blockade of high-mobility group box 1 attenuates intestinal mucosal barrier dysfunction in experimental acute pancreatitis. Sci Rep 2017; 7:6799. [PMID: 28754974 PMCID: PMC5533736 DOI: 10.1038/s41598-017-07094-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/22/2017] [Indexed: 12/26/2022] Open
Abstract
The release of inflammatory cytokines, that plays a dominant role in local pancreatic inflammation and systemic complications in severe acute pancreatitis (SAP). High-mobility group box 1 (HMGB1) is implicated in the mechanism of organ dysfunction and bacterial translocation in SAP. This current study aims to investigate possible role of HMGB1 in the intestinal mucosal barrier dysfunction of SAP, and the effect of anti-HMGB1 antibody treatment in intestinal mucosal injury in SAP. Our data revealed that the HMGB1 expression was significantly increased in AP mice induced by caerulein and LPS, and the inhibition of HMGB1 played a protective role in intestinal mucosal barrier dysfunction, reduced the serum level of other proinflammatory cytokines include IL-1β, IL-6, TNF-α. Next we investigated the downstream receptors involving in HMGB1 signaling. We found that the expressions of toll-like receptor (TLR) 4 and TLR9 were elevated in ileum of AP mice, the administration of HMGB1 neutralizing antibody significantly reduced the TLR4 and TLR9 expression. It was concluded that HMGB1 contributed the mechanism to the intestinal mucosal barrier dysfunction during AP. Blockade of HMGB1 by administration of HMGB1 neutralizing antibody may be a beneficial therapeutic strategy in improving intestinal mucosal barrier dysfunction in SAP.
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Abstract
Helicobacter pylori is the most common bacterial infection worldwide, and virtually all infected persons develop co-existing gastritis. H. pylori is able to send and receive signals from the gastric mucosa, which enables both host and microbe to engage in a dynamic equilibrium. In order to persist within the human host, H. pylori has adopted dichotomous strategies to both induce inflammation as a means of liberating nutrients while simultaneously tempering the immune response to augment its survival. Toll-like receptors (TLRs) and Nod proteins are innate immune receptors that are present in epithelial cells and represent the first line of defense against pathogens. To ensure persistence, H. pylori manipulates TLR-mediated defenses using strategies that include rendering its LPS and flagellin to be non-stimulatory to TLR4 and TLR5, respectively; translocating peptidoglycan into host cells to induce NOD1-mediated anti-inflammatory responses; and translocating DNA into host cells to induce TLR9 activation.
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Sun L, Pan S, Yang Y, Sun J, Liang D, Wang X, Xie X, Hu J. Toll-like receptor 9 regulates melanogenesis through NF-κB activation. Exp Biol Med (Maywood) 2016; 241:1497-504. [PMID: 27075928 DOI: 10.1177/1535370216642529] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/01/2016] [Indexed: 12/22/2022] Open
Abstract
Toll-like receptors play essential roles in the modulation of melanogenesis, which has been implicated in the pathogenesis of hyper- or hypopigmentation-related diseases. However, little is currently known regarding the role of TLR9 in human melanocytes. TLR9 recognizes unmethylated cytosine-phosphate-guanine motif-containing oligodeoxynucleotides, and cytosine-phosphate-guanine ODN2006 acts as an hTLR9 agonist. The aim of the present study was to investigate the effect of cytosine-phosphate-guanine ODN2006 on melanogenesis in the human melanocyte cells. MTT assay and enzyme-linked immunosorbent assay indicated that ODN2006 stimulation (0, 1, 5, 10 µM) dose-dependently reduced cell viability and promoted the production of TNF-α, IL-6, and IL-8 in PIG1 melanocytes. The mRNA and protein levels of PMEL and TYRosinase were elevated at 6 h, and then decreased 24 h later, but were significantly augmented 72 h later following ODN2006 stimulation; whereas, TLR9 expressions were time-dependently increased in PIG1 melanocytes. Moreover, ultraviolet B irradiation combined with ODN2006 stimulation induced much more significant enhancement of PMEL, TYRosinase, and TLR9 mRNA and protein after three days in PIG1 melanocytes, and the similar results were obtained using the primary human melanocytes. The expression of TLR9 protein was down-regulated by TLR9 siRNA transfection. ODN2006 had an additive effect on ultraviolet B-induced melanogenesis and PMEL expression, as well as NF-κB activation, which could be blocked by TLR9 knockdown, the NF-κB specific inhibitor PDTC, or the TBK1 inhibitor BX795. Collectively, we concluded that TLR9 regulates melanogenesis through NF-κB activation, suggesting that TLR9 may play a role in microbial-induced melanogenesis.
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Affiliation(s)
- Lijun Sun
- Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China
| | - Shengjun Pan
- Department of Nursing, Huanghuai University, Zhumadian 463000, China
| | - Yuejin Yang
- Kaifeng Center for Disease Control and Prevention, Kaifeng 475004, China
| | - Jingying Sun
- Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China
| | - Daoyan Liang
- Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China
| | - Xin Wang
- Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China
| | - Xin Xie
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an 710069, China Department of Translational Medicine, Institute of Integrated Medical Information, Xi'an 710016, China
| | - Jun Hu
- Shaanxi Provincial Key Laboratory of Infectious and Immunological Diseases, Shaanxi Provincial People's Hospital, Xi'an 710068, China
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Ge RT, Mo LH, Wu R, Liu JQ, Zhang HP, Liu Z, Liu Z, Yang PC. Insulin-like growth factor-1 endues monocytes with immune suppressive ability to inhibit inflammation in the intestine. Sci Rep 2015; 5:7735. [PMID: 25588622 PMCID: PMC4295102 DOI: 10.1038/srep07735] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 12/10/2014] [Indexed: 12/21/2022] Open
Abstract
The pathogenesis of some chronic inflammation such as inflammatory bowel disease is unclear. Insulin-like growth factor-1 (IGF1) has active immune regulatory capability. This study aims to investigate into the mechanism by which IGF1 modulates the monocyte (Mo) properties to inhibit immune inflammation in the intestine. In this study, the production of IGF1 by intestinal epithelial cells was evaluated by real time RT-PCR and Western blotting. Mos were analyzed by flow cytometry. A mouse colitis model was created with trinitrobenzene sulfonic acid. The results showed that mouse IECs produced IGF1, which could be up regulated by exposure to CpG-ODN (CpG-oligodeoxynueleotides) in the culture. Culture the CpG-ODN-primed IEC cells and Mos or exposure of Mos to IGF1 in the culture induced the Mos to express IL-10. The IGF1-primed Mos showed the immune suppressive effect on inhibiting the immune inflammation in the mouse colon. In conclusion, the IGF1-primed Mos are capable of suppressing immune inflammation in the intestine.
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Affiliation(s)
- Rong-Ti Ge
- 1] Department of Gastroenterology, The Shanghai Tenth People's Hospital of Tongji University, Shanghai, 200072, China [2] Brain Body Institute, McMaster University, Hamilton, ON, Canada L8N 4A6
| | - Li-Hua Mo
- Shenzhen Key Laboratory of Allergy &Immunology, Shenzhen University School of Medicine and State Key Laboratory of Respiratory Disease for Allergy at Shenzhen University, Shenzhen, 518060, China
| | - Ruijin Wu
- Department of Gastroenterology, The Shanghai Tenth People's Hospital of Tongji University, Shanghai, 200072, China
| | - Jiang-Qi Liu
- Brain Body Institute, McMaster University, Hamilton, ON, Canada L8N 4A6
| | - Huan-Ping Zhang
- Brain Body Institute, McMaster University, Hamilton, ON, Canada L8N 4A6
| | - Zhigang Liu
- Shenzhen Key Laboratory of Allergy &Immunology, Shenzhen University School of Medicine and State Key Laboratory of Respiratory Disease for Allergy at Shenzhen University, Shenzhen, 518060, China
| | - Zhanju Liu
- Department of Gastroenterology, The Shanghai Tenth People's Hospital of Tongji University, Shanghai, 200072, China
| | - Ping-Chang Yang
- 1] Shenzhen Key Laboratory of Allergy &Immunology, Shenzhen University School of Medicine and State Key Laboratory of Respiratory Disease for Allergy at Shenzhen University, Shenzhen, 518060, China [2] Brain Body Institute, McMaster University, Hamilton, ON, Canada L8N 4A6
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