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Caputi V, Giron MC. Microbiome-Gut-Brain Axis and Toll-Like Receptors in Parkinson's Disease. Int J Mol Sci 2018; 19:ijms19061689. [PMID: 29882798 PMCID: PMC6032048 DOI: 10.3390/ijms19061689] [Citation(s) in RCA: 209] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 05/31/2018] [Accepted: 06/03/2018] [Indexed: 12/14/2022] Open
Abstract
Parkinson’s disease (PD) is a progressively debilitating neurodegenerative disease characterized by α-synucleinopathy, which involves all districts of the brain-gut axis, including the central, autonomic and enteric nervous systems. The highly bidirectional communication between the brain and the gut is markedly influenced by the microbiome through integrated immunological, neuroendocrine and neurological processes. The gut microbiota and its relevant metabolites interact with the host via a series of biochemical and functional inputs, thereby affecting host homeostasis and health. Indeed, a dysregulated microbiota-gut-brain axis in PD might lie at the basis of gastrointestinal dysfunctions which predominantly emerge many years prior to the diagnosis, corroborating the theory that the pathological process is spread from the gut to the brain. Toll-like receptors (TLRs) play a crucial role in innate immunity by recognizing conserved motifs primarily found in microorganisms and a dysregulation in their signaling may be implicated in α-synucleinopathy, such as PD. An overstimulation of the innate immune system due to gut dysbiosis and/or small intestinal bacterial overgrowth, together with higher intestinal barrier permeability, may provoke local and systemic inflammation as well as enteric neuroglial activation, ultimately triggering the development of alpha-synuclein pathology. In this review, we provide the current knowledge regarding the relationship between the microbiota-gut⁻brain axis and TLRs in PD. A better understanding of the dialogue sustained by the microbiota-gut-brain axis and innate immunity via TLR signaling should bring interesting insights in the pathophysiology of PD and provide novel dietary and/or therapeutic measures aimed at shaping the gut microbiota composition, improving the intestinal epithelial barrier function and balancing the innate immune response in PD patients, in order to influence the early phases of the following neurodegenerative cascade.
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Affiliation(s)
- Valentina Caputi
- Pharmacology Building, Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy.
- APC Microbiome Ireland, University College Cork, T12YT20 Cork, Ireland.
| | - Maria Cecilia Giron
- Pharmacology Building, Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy.
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Mishra V, Pathak C. Structural insights into pharmacophore-assisted in silico identification of protein-protein interaction inhibitors for inhibition of human toll-like receptor 4 - myeloid differentiation factor-2 (hTLR4-MD-2) complex. J Biomol Struct Dyn 2018; 37:1968-1991. [PMID: 29842849 DOI: 10.1080/07391102.2018.1474804] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Toll-like receptor 4 (TLR4) is a member of Toll-Like Receptors (TLRs) family that serves as a receptor for bacterial lipopolysaccharide (LPS). TLR4 alone cannot recognize LPS without aid of co-receptor myeloid differentiation factor-2 (MD-2). Binding of LPS with TLR4 forms a LPS-TLR4-MD-2 complex and directs downstream signaling for activation of immune response, inflammation and NF-κB activation. Activation of TLR4 signaling is associated with various pathophysiological consequences. Therefore, targeting protein-protein interaction (PPI) in TLR4-MD-2 complex formation could be an attractive therapeutic approach for targeting inflammatory disorders. The aim of present study was directed to identify small molecule PPI inhibitors (SMPPIIs) using pharmacophore mapping-based approach of computational drug discovery. Here, we had retrieved the information about the hot spot residues and their pharmacophoric features at both primary (TLR4-MD-2) and dimerization (MD-2-TLR4*) protein-protein interaction interfaces in TLR4-MD-2 homo-dimer complex using in silico methods. Promising candidates were identified after virtual screening, which may restrict TLR4-MD-2 protein-protein interaction. In silico off-target profiling over the virtually screened compounds revealed other possible molecular targets. Two of the virtually screened compounds (C11 and C15) were predicted to have an inhibitory concentration in μM range after HYDE assessment. Molecular dynamics simulation study performed for these two compounds in complex with target protein confirms the stability of the complex. After virtual high throughput screening we found selective hTLR4-MD-2 inhibitors, which may have therapeutic potential to target chronic inflammatory diseases.
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Affiliation(s)
- Vinita Mishra
- a Department of Cell Biology, School of Biological Sciences & Biotechnology , Indian Institute of Advanced Research, Koba Institutional Area , Gandhinagar , India
| | - Chandramani Pathak
- a Department of Cell Biology, School of Biological Sciences & Biotechnology , Indian Institute of Advanced Research, Koba Institutional Area , Gandhinagar , India
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Abstract
PURPOSE OF REVIEW The urinary tract is the infection site in severe sepsis/septic shock in 10-30%. RECENT FINDINGS There is a new Sepsis definition focusing on severe sepsis. Urosepsis is mainly due to obstructed uropathy of the upper urinary tract. The pathogenesis of sepsis is complex and is driven by the innate immune system. In the further course immunosuppression is developing.Management of urosepsis includes early diagnosis, early initiation of treatment such as identification and control of the complicating factor in the urinary tract and the specific sepsis therapy. As part of early diagnosis the value of the new defining criteria is still to be known. The management bundles are regularly updated according to the surviving sepsis campaign guidelines. SUMMARY Sepsis has still a high morbidity and mortality rate. Although definition and diagnosis of sepsis has been recently updated, its translation into urosepsis management requires validation.
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Natural Products with Toll-Like Receptor 4 Antagonist Activity. Int J Inflam 2018; 2018:2859135. [PMID: 29686833 PMCID: PMC5852877 DOI: 10.1155/2018/2859135] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/09/2018] [Accepted: 01/30/2018] [Indexed: 01/25/2023] Open
Abstract
Toll-Like Receptors (TLRs) are the innate immunity receptors that play an activating role when interacting with molecules released by bacteria and viruses (PAMPs, pathogen-associated molecular patterns) or with molecules released by injured cells and tissues (DAMPs, danger-associated molecular patterns). TLR triggering leads to the induction of proinflammatory cytokines and chemokines, driving the activation of both innate and adaptive immunity. In particular, Toll-Like Receptor 4 (TLR4) has been described to be involved in the inflammatory processes observed in several pathologies (such as ischemia/reperfusion injury, neuropathic pain, neurodegenerative diseases, and cancer). Molecules obtained by natural sources have been discovered to exert an anti-inflammatory action by targeting TLR4 activation pathways. This review focuses on TLR4 antagonists obtained from bacteria, cyanobacteria, and plants.
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Gao J, Guo Z. Progress in the synthesis and biological evaluation of lipid A and its derivatives. Med Res Rev 2018; 38:556-601. [PMID: 28621828 PMCID: PMC5732894 DOI: 10.1002/med.21447] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 03/09/2017] [Accepted: 04/20/2017] [Indexed: 12/31/2022]
Abstract
Lipid A is one of the core structures of bacterial lipopolysaccharides (LPSs), and it is mainly responsible for the strong immunostimulatory activities of LPS through interactions with the Toll-like receptors and other molecules in the human immune system. To obtain structurally homogeneous and well-defined lipid As and its derivatives in quantities meaningful for various biological studies and applications, their chemical synthesis has become a focal point. This review has provided a survey of significant progresses made in the synthesis of lipid A, and its derivatives that carry diverse saturated and unsaturated lipids, have the phosphate group at its reducing end replaced with a more stable phosphate or carboxyl group, or lack the reducing end phosphate or both phosphate groups, as well as progresses in the synthesis of LPS analogs and other lipid A conjugates. These synthetic molecules have facilitated the elucidation of the structure-activity relationships of lipid A useful for the design and development of lipid A based therapeutics, such as those utilized to treat sepsis, and other medical applications, for example the use of monophosphoryl lipid A as a carrier molecule for the study of fully synthetic self-adjuvanting conjugate vaccines. These topics are also briefly covered in the current review.
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Affiliation(s)
- Jian Gao
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, 27 Shanda Nan Lu, Jinan 250100, China
| | - Zhongwu Guo
- Department of Chemistry, University of Florida, 214 Leigh Hall, Gainesville, Florida 32611, United States
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Sircana A, De Michieli F, Parente R, Framarin L, Leone N, Berrutti M, Paschetta E, Bongiovanni D, Musso G. Gut microbiota, hypertension and chronic kidney disease: Recent advances. Pharmacol Res 2018; 144:390-408. [PMID: 29378252 DOI: 10.1016/j.phrs.2018.01.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/29/2017] [Accepted: 01/22/2018] [Indexed: 02/07/2023]
Abstract
A large number of different microbial species populates intestine. Extensive research has studied the entire microbial population and their genes (microbiome) by using metagenomics, metatranscriptomics and metabolomic analysis. Studies suggest that the imbalances of the microbial community causes alterations in the intestinal homeostasis, leading to repercussions on other systems: metabolic, nervous, cardiovascular, immune. These studies have also shown that alterations in the structure and function of the gut microbiota play a key role in the pathogenesis and complications of Hypertension (HTN) and Chronic Kidney Disease (CKD). Increased blood pressure (BP) and CKD are two leading risk factors for cardiovascular disease and their treatment represents a challenge for the clinicians. In this Review, we discuss mechanisms whereby gut microbiota (GM) and its metabolites act on downstream cellular targets to contribute to the pathogenesis of HTN and CKD, and potential therapeutic implications.
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Affiliation(s)
- Antonio Sircana
- Unità Operativa di Cardiologia, Azienda Ospedaliero Universitaria, Sassari, Italy; Department of Medical Sciences, San Giovanni Battista Hospital, Turin, Italy
| | - Franco De Michieli
- HUMANITAS Gradenigo, University of Turin, Turin, Italy; Department of Medical Sciences, San Giovanni Battista Hospital, Turin, Italy
| | - Renato Parente
- HUMANITAS Gradenigo, University of Turin, Turin, Italy; Department of Medical Sciences, San Giovanni Battista Hospital, Turin, Italy
| | - Luciana Framarin
- HUMANITAS Gradenigo, University of Turin, Turin, Italy; Department of Medical Sciences, San Giovanni Battista Hospital, Turin, Italy
| | - Nicola Leone
- HUMANITAS Gradenigo, University of Turin, Turin, Italy; Department of Medical Sciences, San Giovanni Battista Hospital, Turin, Italy
| | - Mara Berrutti
- HUMANITAS Gradenigo, University of Turin, Turin, Italy; Department of Medical Sciences, San Giovanni Battista Hospital, Turin, Italy
| | - Elena Paschetta
- HUMANITAS Gradenigo, University of Turin, Turin, Italy; Department of Medical Sciences, San Giovanni Battista Hospital, Turin, Italy
| | - Daria Bongiovanni
- HUMANITAS Gradenigo, University of Turin, Turin, Italy; Department of Medical Sciences, San Giovanni Battista Hospital, Turin, Italy
| | - Giovanni Musso
- HUMANITAS Gradenigo, University of Turin, Turin, Italy; Department of Medical Sciences, San Giovanni Battista Hospital, Turin, Italy.
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Zou Y, Qin F, Chen J, Meng J, Wei L, Wu C, Zhang Q, Wei D, Chen X, Wu H, Chen X, Dai S. sTLR4/MD-2 complex inhibits colorectal cancer in vitro and in vivo by targeting LPS. Oncotarget 2018; 7:52032-52044. [PMID: 27409669 PMCID: PMC5239533 DOI: 10.18632/oncotarget.10496] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/30/2016] [Indexed: 12/18/2022] Open
Abstract
Colorectal cancer (CRC) is aggressive and associated with TLR4-MD-2 signaling. Toll-like receptor 4 (TLR4) and myeloid differentiation protein 2 (MD-2) were highly expressed in human CRC. The soluble form of extracellular TLR4 domain (sTLR4) and MD-2 may have important roles in binding lipopolysaccharide (LPS). In this study, sTLR4 and MD-2 protein and prepared sTLR4/MD-2 complex were synthesized successfully to restrain LPS-TLR4/MD-2 activation by competing with cellular membrane TLR4 for binding LPS. The sTLR4/MD-2 complex can significantly attenuate LPS induced pro-inflammatory and migration cytokine production in vitro and in vivo, and inhibit the effect of LPS on the cell cycle, migration and invasion of human CRC cells in vitro. Administration of sTLR4/MD-2 complex protected mice from tumor both in xenograft and implantation metastasis model. The sTLR4/MD-2 complex treated mice had smaller tumor, less body weight loss and lower expression of inflammatory cytokines. Here, the azoxymethane/dextran sulfate sodium salt (AOM/DSS) murine model was used as an experimental platform to simulate the physiological and pathological processes of cancers associated with chronic intestinal inflammation. AOM/DSS-induced tumors were inhibited in mice treated by sTLR4/MD-2 complex. It is demonstrated in our study that sTLR4/MD-2 complex could inhibit CRC by competing with binding LPS, raising the complex's possibility of a new prevention agent against CRC.
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Affiliation(s)
- Yan Zou
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Fengxian Qin
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Jifei Chen
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Jie Meng
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Liuhua Wei
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Chunlin Wu
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Qiaoyun Zhang
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Dong Wei
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Xiang Chen
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Hao Wu
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Xiaoli Chen
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
| | - Shengming Dai
- Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545005, P.R. China
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Chen L, Fu W, Zheng L, Wang Y, Liang G. Recent progress in the discovery of myeloid differentiation 2 (MD2) modulators for inflammatory diseases. Drug Discov Today 2018; 23:1187-1202. [PMID: 29330126 DOI: 10.1016/j.drudis.2018.01.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/09/2017] [Accepted: 01/04/2018] [Indexed: 02/07/2023]
Abstract
Myeloid differentiation protein 2 (MD2), together with Toll-like receptor 4 (TLR4), binds lipopolysaccharide (LPS) with high affinity, inducing the formation of the activated homodimer LPS-MD2-TLR4. MD2 directly recognizes the Lipid A domain of LPS, leading to the activation of downstream signaling of cytokine and chemokine production, and initiation of inflammatory and immune responses. However, excessive activation and potent host responses generate severe inflammatory syndromes such as acute sepsis and septic shock. MD2 is increasingly being considered as an attractive pharmacological target for the development of potent anti-inflammatory agents. In this Keynote review, we provide a comprehensive overview of the recent advances in the structure and biology of MD2, and present MD2 modulators as promising agents for anti-inflammatory intervention.
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Affiliation(s)
- Lingfeng Chen
- Chemical Biology Research Center at School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China; School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Weitao Fu
- Chemical Biology Research Center at School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Lulu Zheng
- Chemical Biology Research Center at School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yi Wang
- Chemical Biology Research Center at School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.
| | - Guang Liang
- Chemical Biology Research Center at School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China; School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
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Discovery of caffeic acid phenethyl ester derivatives as novel myeloid differentiation protein 2 inhibitors for treatment of acute lung injury. Eur J Med Chem 2017; 143:361-375. [PMID: 29202400 DOI: 10.1016/j.ejmech.2017.11.066] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/22/2017] [Accepted: 11/24/2017] [Indexed: 12/26/2022]
Abstract
Myeloid differentiation protein 2 (MD2) is an essential molecule which recognizes lipopolysaccharide (LPS), leading to initiation of inflammation through the activation of Toll-like receptor 4 (TLR4) signaling. Caffeic acid phenethyl ester (CAPE) from propolis of honeybee hives could interfere interactions between LPS and the TLR4/MD2 complex, and thereby has promising anti-inflammatory properties. In this study, we designed and synthesized 48 CAPE derivatives and evaluated their anti-inflammatory activities in mouse primary peritoneal macrophages (MPMs) activated by LPS. The most active compound, 10s, was found to bind with MD2 with high affinity, which prevented formation of the LPS/MD2/TLR4 complex. The binding mode of 10s revealed that the major interactions with MD2 were established via two key hydrogen bonds and hydrophobic interactions. Furthermore, 10s showed remarkable protective effects against LPS-caused ALI (acute lung injury) in vivo. Taken together, this work provides new lead structures and candidates as MD2 inhibitors for the development of anti-inflammatory drugs.
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Zhang Y, Igwe OJ. Exogenous oxidants activate nuclear factor kappa B through Toll-like receptor 4 stimulation to maintain inflammatory phenotype in macrophage. Biochem Pharmacol 2017; 147:104-118. [PMID: 29175419 DOI: 10.1016/j.bcp.2017.11.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 11/21/2017] [Indexed: 01/06/2023]
Abstract
Disturbances in redox equilibrium in tissue can lead to inflammatory state, which is a mediatory factor in many human diseases. The mechanism(s) by which exogenous oxidants may activate an inflammatory response is not fully understood. Emerging evidence suggests that oxidant-induced Toll-like receptor 4 (TLR4) activation plays a major role in "sterile" inflammation. In the present study, we used murine macrophage RAW-Blue cells, which are chromosomally integrated with secreted embryonic alkaline phosphatase (SEAP) inducible by NF-κB. We confirmed the expression of TLR4 mRNA and protein in RAW-Blue cells by RT-PCR and Western blot, respectively. We showed that oxidants increased intracellular reactive oxygen species production and lipid peroxidation, which resulted in decreased intracellular total antioxidant capacity. Consistent with the actions of TLR4-specific agonist LPS-EK, exogenous oxidants increased transcriptional activity of NF-κB p65 with subsequent release of NF-κB reporter gene SEAP. These effects were blocked by pretreatment with TLR4 neutralizing pAb and TLR4 signaling inhibitor CLI-095. In addition, oxidants decreased the expression of IκBα with enhanced phosphorylation at the Tyr42 residue. Finally, oxidants and LPS-EK increased TNFα production, but did not affect IL-10 production, which may cause imbalance between pro- and anti-inflammatory processes, which CLI-095 inhibited. For biological relevance, we confirmed that oxidants increased release of TNFα and IL-6 in primary macrophages derived from TLR4-WT and TLR4-KO mice. Our results support the involvement of TLR4 mediated oxidant-induced inflammatory phenotype through NF-κB activation in macrophages. Thus exogenous oxidants may play a role in activating inflammatory phenotypes that propagate and maintain chronic disease states.
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Affiliation(s)
- Yan Zhang
- University of Missouri-Kansas City, School of Pharmacy, Division of Pharmacology & Toxicology, 2464 Charlotte Street, Kansas City, MO 64108, USA.
| | - Orisa J Igwe
- University of Missouri-Kansas City, School of Pharmacy, Division of Pharmacology & Toxicology, 2464 Charlotte Street, Kansas City, MO 64108, USA.
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61
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Hermier D, Mathé V, Lan A, Santini C, Quignard-Boulangé A, Huneau JF, Mariotti F. Postprandial low-grade inflammation does not specifically require TLR4 activation in the rat. Nutr Metab (Lond) 2017; 14:65. [PMID: 29075306 PMCID: PMC5649083 DOI: 10.1186/s12986-017-0220-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 10/12/2017] [Indexed: 12/31/2022] Open
Abstract
Background Toll-like receptor 4 (TLR4), an innate immune receptor, is suspected to play a key role in the postprandial inflammation that is induced by a high-fat meal rich in saturated fatty acids (SFA). Our objective was to test this hypothesis by using a specific competitive inhibitor of TLR4 (INH) vs vehicle (VEH) administered immediately before a high-SFA meal in rats. Methods First, in a cross-over kinetic study of 12 rats receiving INH and VEH i.v. 10 min before the test meal, we measured plasma inflammatory and vascular markers for 6 h. Then, in 20 rats, 3 h after INH or VEH followed by the test meal (parallel study), we measured the mRNA level of a set of cytokines (Il1-β, Il-6, Tnfα, Mcp-1, Pai-1), and of Tlr4 and Tlr2 in the adipose tissue and the liver, and that of adhesion molecules (Icam-1 and Vcam-1) in the aorta. Results Plasma IL-6 and PAI-1 increased >4-fold at 3–4 h after test-meals, very similarly after INH as compared to VEH. The expression of TLR2 and of all measured cytokine genes in the adipose tissue was dramatically higher after INH (vs VEH). In the liver, gene expression of Il1-β, Tnfα, Mcp-1 and Tlr2, was also higher after INH, though more moderately, whereas that of Il-6 and Pai-1 was similar between groups. INH did not affect mRNA level of Icam-1 and Vcam-1 in the aorta. Conclusion TLR4 activation is not specifically required to mediate systemic postprandial inflammation and we propose that TLR2 and TLR4 exert a dual and interdependent mediation of the postprandial inflammatory response, at least in the adipose tissue.
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Affiliation(s)
- Dominique Hermier
- UMR Physiologie de la Nutrition et du Comportement Alimentaire, AgroParisTech, INRA, Université Paris-Saclay, 16 rue Claude Bernard, F-75005 Paris, France
| | - Véronique Mathé
- UMR Physiologie de la Nutrition et du Comportement Alimentaire, AgroParisTech, INRA, Université Paris-Saclay, 16 rue Claude Bernard, F-75005 Paris, France
| | - Annaïg Lan
- UMR Physiologie de la Nutrition et du Comportement Alimentaire, AgroParisTech, INRA, Université Paris-Saclay, 16 rue Claude Bernard, F-75005 Paris, France
| | - Clélia Santini
- UMR Physiologie de la Nutrition et du Comportement Alimentaire, AgroParisTech, INRA, Université Paris-Saclay, 16 rue Claude Bernard, F-75005 Paris, France
| | - Annie Quignard-Boulangé
- UMR Physiologie de la Nutrition et du Comportement Alimentaire, AgroParisTech, INRA, Université Paris-Saclay, 16 rue Claude Bernard, F-75005 Paris, France
| | - Jean-François Huneau
- UMR Physiologie de la Nutrition et du Comportement Alimentaire, AgroParisTech, INRA, Université Paris-Saclay, 16 rue Claude Bernard, F-75005 Paris, France
| | - François Mariotti
- UMR Physiologie de la Nutrition et du Comportement Alimentaire, AgroParisTech, INRA, Université Paris-Saclay, 16 rue Claude Bernard, F-75005 Paris, France
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TLR4 Signaling Pathway Modulators as Potential Therapeutics in Inflammation and Sepsis. Vaccines (Basel) 2017; 5:vaccines5040034. [PMID: 28976923 PMCID: PMC5748601 DOI: 10.3390/vaccines5040034] [Citation(s) in RCA: 356] [Impact Index Per Article: 50.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 09/29/2017] [Accepted: 10/01/2017] [Indexed: 02/06/2023] Open
Abstract
Toll-Like Receptor 4 (TLR4) signal pathway plays an important role in initiating the innate immune response and its activation by bacterial endotoxin is responsible for chronic and acute inflammatory disorders that are becoming more and more frequent in developed countries. Modulation of the TLR4 pathway is a potential strategy to specifically target these pathologies. Among the diseases caused by TLR4 abnormal activation by bacterial endotoxin, sepsis is the most dangerous one because it is a life-threatening acute system inflammatory condition that still lacks specific pharmacological treatment. Here, we review molecules at a preclinical or clinical phase of development, that are active in inhibiting the TLR4-MyD88 and TLR4-TRIF pathways in animal models. These are low-molecular weight compounds of natural and synthetic origin that can be considered leads for drug development. The results of in vivo studies in the sepsis model and the mechanisms of action of drug leads are presented and critically discussed, evidencing the differences in treatment results from rodents to humans.
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Abstract
Hepatocellular carcinoma (HCC) is the third leading cause of worldwide cancer mortality. HCC almost exclusively develops in patients with chronic liver disease, driven by a vicious cycle of liver injury, inflammation and regeneration that typically spans decades. Increasing evidence points towards a key role of the bacterial microbiome in promoting the progression of liver disease and the development of HCC. Here, we will review mechanisms by which the gut microbiota promotes hepatocarcinogenesis, focusing on the leaky gut, bacterial dysbiosis, microbe-associated molecular patterns and bacterial metabolites as key pathways that drive cancer-promoting liver inflammation, fibrosis and genotoxicity. On the basis of accumulating evidence from preclinical studies, we propose the intestinal-microbiota-liver axis as a promising target for the simultaneous prevention of chronic liver disease progression and HCC development in patients with advanced liver disease. We will review in detail therapeutic modalities and discuss clinical settings in which targeting the gut-microbiota-liver axis for the prevention of disease progression and HCC development seems promising.
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Affiliation(s)
- Le-Xing Yu
- Department of Medicine, Columbia University, 1130 St. Nicholas Avenue, Room 926, New York, New York 10032, USA
| | - Robert F Schwabe
- Department of Medicine, Columbia University, 1130 St. Nicholas Avenue, Room 926, New York, New York 10032, USA
- Institute of Human Nutrition, 1130 St. Nicholas Avenue, Room 926, New York, New York 10032, USA
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Epigallocatechin-3-gallate inhibits TLR4 signaling through the 67-kDa laminin receptor and effectively alleviates acute lung injury induced by H9N2 swine influenza virus. Int Immunopharmacol 2017; 52:24-33. [PMID: 28858723 DOI: 10.1016/j.intimp.2017.08.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/24/2017] [Accepted: 08/25/2017] [Indexed: 11/22/2022]
Abstract
Epigallocatechin-3-gallate (EGCG) was found to inhibit the Toll-like receptor 4 (TLR4) pathway involved in influenza virus pathogenesis. Here, the effect of EGCG on TLR4 in an H9N2 virus-induced acute lung injury mouse model was investigated. BALB/c mice were inoculated intranasally with A/Swine/Hebei/108/2002 (H9N2) virus or noninfectious allantoic fluid, and treated with EGCG and E5564 or normal saline orally for 5 consecutive days. PMVECs were treated with EGCG or anti-67kDa laminin receptor (LR). Lung physiopathology, inflammation, oxidative stress, viral replication, and TLR4/NF-κB/Toll-interacting protein (Tollip) pathway in lung tissue and/or PMVECs were investigated. EGCG attenuated lung histological lesions, decreased lung W/D ratio, cytokines levels, and inhibited MPO activity and prolonged mouse survival. EGCG treatment also markedly downregulated TLR4 and NF-κB protein levels but Tollip expression was upregulated compared with that in untreated H9N2-infected mice (P<0.05). In PMVECs, anti-67LR antibody treatment significantly downregulated Tollip levels; however, the TLR4 and NF-κB protein levels dramatically increased compared with that in the EGCG-treated group (P<0.05). EGCG remarkably downregulated TLR4 protein levels through 67LR/Tollip, decreased MPO activity and inflammatory cytokine levels, supporting EGCG as a potential therapeutic agent for managing acute lung injury induced by H9N2 SIV.
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65
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Pahari S, Kaur G, Aqdas M, Negi S, Chatterjee D, Bashir H, Singh S, Agrewala JN. Bolstering Immunity through Pattern Recognition Receptors: A Unique Approach to Control Tuberculosis. Front Immunol 2017; 8:906. [PMID: 28824632 PMCID: PMC5539433 DOI: 10.3389/fimmu.2017.00906] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 07/14/2017] [Indexed: 12/24/2022] Open
Abstract
The global control of tuberculosis (TB) presents a continuous health challenge to mankind. Despite having effective drugs, TB still has a devastating impact on human health. Contributing reasons include the emergence of drug-resistant strains of Mycobacterium tuberculosis (Mtb), the AIDS-pandemic, and the absence of effective vaccines against the disease. Indeed, alternative and effective methods of TB treatment and control are urgently needed. One such approach may be to more effectively engage the immune system; particularly the frontline pattern recognition receptor (PRR) systems of the host, which sense pathogen-associated molecular patterns (PAMPs) of Mtb. It is well known that 95% of individuals infected with Mtb in latent form remain healthy throughout their life. Therefore, we propose that clues can be found to control the remainder by successfully manipulating the innate immune mechanisms, particularly of nasal and mucosal cavities. This article highlights the importance of signaling through PRRs in restricting Mtb entry and subsequently preventing its infection. Furthermore, we discuss whether this unique therapy employing PRRs in combination with drugs can help in reducing the dose and duration of current TB regimen.
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Affiliation(s)
- Susanta Pahari
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Gurpreet Kaur
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Mohammad Aqdas
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Shikha Negi
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Deepyan Chatterjee
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Hilal Bashir
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Sanpreet Singh
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Javed N Agrewala
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India
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Li Q, Feng Y, He W, Wang L, Wang R, Dong L, Wang C. Post-screening characterisation and in vivo evaluation of an anti-inflammatory polysaccharide fraction from Eucommia ulmoides. Carbohydr Polym 2017; 169:304-314. [DOI: 10.1016/j.carbpol.2017.04.034] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/28/2017] [Accepted: 04/14/2017] [Indexed: 12/18/2022]
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67
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Yang H, Fung SY, Bao A, Li Q, Turvey SE. Screening Bioactive Nanoparticles in Phagocytic Immune Cells for Inhibitors of Toll-like Receptor Signaling. J Vis Exp 2017. [PMID: 28784964 DOI: 10.3791/56075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Pharmacological regulation of Toll-like receptor (TLR) responses holds great promise in the treatment of many inflammatory diseases. However, there have been limited compounds available so far to attenuate TLR signaling and there have been no clinically approved TLR inhibitors (except the anti-malarial drug hydroxychloroquine) in clinical use. In light of rapid advances in nanotechnology, manipulation of immune responsiveness using nano-devices may provide a new strategy to treat these diseases. Herein, we present a high throughput screening method for quickly identifying novel bioactive nanoparticles that inhibit TLR signaling in phagocytic immune cells. This screening platform is built on THP-1 cell-based reporter cells with colorimetric and luciferase assays. The reporter cells are engineered from the human THP-1 monocytic cell line by stable integration of two inducible reporter constructs. One expresses a secreted embryonic alkaline phosphatase (SEAP) gene under the control of a promoter inducible by the transcription factors NF-κB and AP-1, and the other expresses a secreted luciferase reporter gene under the control of promoters inducible by interferon regulatory factors (IRFs).Upon TLR stimulation, the reporter cells activate transcription factors and subsequently produce SEAP and/or luciferase, which can be detected using their corresponding substrate reagents. Using a library of peptide-gold nanoparticle (GNP) hybrids established in our previous studies as an example, we identified one peptide-GNP hybrid that could effectively inhibit the two arms of TLR4 signaling cascade triggered by its prototypical ligand, lipopolysaccharide (LPS). The findings were validated by standard biochemical techniques including immunoblotting. Further analysis established that this lead hybrid had a broad inhibitory spectrum, acting on multiple TLR pathways, including TLR2, 3, 4, and 5. This experimental approach allows a rapid assessment of whether a nanoparticle (or other therapeutic compounds) can modulate specific TLR signaling in phagocytic immune cells.
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Affiliation(s)
- Hong Yang
- Department of Respiratory Medicine, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine;
| | - Shan Yu Fung
- Department of Pediatrics, BC Children's Hospital and University of British Columbia
| | - Aihua Bao
- Department of Respiratory Medicine, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine
| | - Qiang Li
- Department of Respiratory Medicine, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine
| | - Stuart E Turvey
- Department of Pediatrics, BC Children's Hospital and University of British Columbia
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68
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Gao W, Xiong Y, Li Q, Yang H. Inhibition of Toll-Like Receptor Signaling as a Promising Therapy for Inflammatory Diseases: A Journey from Molecular to Nano Therapeutics. Front Physiol 2017; 8:508. [PMID: 28769820 PMCID: PMC5516312 DOI: 10.3389/fphys.2017.00508] [Citation(s) in RCA: 238] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 07/03/2017] [Indexed: 12/20/2022] Open
Abstract
The recognition of invading pathogens and endogenous molecules from damaged tissues by toll-like receptors (TLRs) triggers protective self-defense mechanisms. However, excessive TLR activation disrupts the immune homeostasis by sustained pro-inflammatory cytokines and chemokines production and consequently contributes to the development of many inflammatory and autoimmune diseases, such as systemic lupus erythematosus (SLE), infection-associated sepsis, atherosclerosis, and asthma. Therefore, inhibitors/antagonists targeting TLR signals may be beneficial to treat these disorders. In this article, we first briefly summarize the pathophysiological role of TLRs in the inflammatory diseases. We then focus on reviewing the current knowledge in both preclinical and clinical studies of various TLR antagonists/inhibitors for the prevention and treatment of inflammatory diseases. These compounds range from conventional small molecules to therapeutic biologics and nanodevices. In particular, nanodevices are emerging as a new class of potent TLR inhibitors for their unique properties in desired bio-distribution, sustained circulation, and preferred pharmacodynamic and pharmacokinetic profiles. More interestingly, the inhibitory activity of these nanodevices can be regulated through precise nano-functionalization, making them the next generation therapeutics or “nano-drugs.” Although, significant efforts have been made in developing different kinds of new TLR inhibitors/antagonists, only limited numbers of them have undergone clinical trials, and none have been approved for clinical uses to date. Nevertheless, these findings and continuous studies of TLR inhibition highlight the pharmacological regulation of TLR signaling, especially on multiple TLR pathways, as future promising therapeutic strategy for various inflammatory and autoimmune diseases.
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Affiliation(s)
- Wei Gao
- Department of Respiratory Medicine, Shanghai First People's Hospital, Shanghai Jiaotong University School of MedicineShanghai, China
| | - Ye Xiong
- Department of Respiratory Medicine, Changhai Hospital, Second Military Medical UniversityShanghai, China
| | - Qiang Li
- Department of Respiratory Medicine, Shanghai First People's Hospital, Shanghai Jiaotong University School of MedicineShanghai, China
| | - Hong Yang
- Department of Respiratory Medicine, Shanghai First People's Hospital, Shanghai Jiaotong University School of MedicineShanghai, China
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69
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Prebiotics: A Novel Approach to Treat Hepatocellular Carcinoma. Can J Gastroenterol Hepatol 2017; 2017:6238106. [PMID: 28573132 PMCID: PMC5442341 DOI: 10.1155/2017/6238106] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 04/19/2017] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma is one of the fatal malignancies and is considered as the third leading cause of death. Mutations, genetic modifications, dietary aflatoxins, or impairments in the regulation of oncogenic pathways may bring about liver cancer. An effective barrier against hepatotoxins is offered by gut-liver axis as a change in gut permeability and expanded translocation of lipopolysaccharides triggers the activation of Toll-like receptors which stimulate the process of hepatocarcinogenesis. Prebiotics, nondigestible oligosaccharides, have a pivotal role to play when it comes to inducing an antitumor effect. A healthy gut flora balance is imperative to downregulation of inflammatory cytokines and reducing lipopolysaccharides induced endotoxemia, thus inducing the antitumor effect.
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70
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Monnet E, Lapeyre G, Poelgeest EV, Jacqmin P, Graaf KD, Reijers J, Moerland M, Burggraaf J, Min CD. Evidence of NI-0101 pharmacological activity, an anti-TLR4 antibody, in a randomized phase I dose escalation study in healthy volunteers receiving LPS. Clin Pharmacol Ther 2016; 101:200-208. [PMID: 27706798 DOI: 10.1002/cpt.522] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/31/2016] [Accepted: 09/21/2016] [Indexed: 12/19/2022]
Abstract
Toll-like receptor-4 (TLR4) pathways are major contributors to pathological inflammatory responses induced by tissue damage. NI-0101 is the first monoclonal antibody (mAb) blocking TLR4 signaling. This activity is independent of the ligand type and concentration, therefore, potentially blocking any TLR4 ligands. A phase I single ascending dose study was conducted in 73 healthy volunteers to evaluate NI-0101 tolerability, preliminary safety, pharmacokinetics (PKs), and pharmacodynamics (PDs), in absence and in presence of a systemic challenge with lipopolysaccharide (LPS), a TLR4 ligand. NI-0101 was well tolerated without safety concern. The PK profile was characterized by a half-life of ∼10 days at high concentrations and by a rapid elimination at low concentrations due to expected target-mediated drug disposition. NI-0101 prevented cytokine release following ex vivo and in vivo LPS administration and prevented the C-reactive protein (CRP) increase and the occurrence of flu-like symptoms expected following the in vivo administration of LPS.
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Affiliation(s)
- E Monnet
- Novimmune SA, Plan-les-Ouates, Switzerland.,MnS, Belgium
| | - G Lapeyre
- Novimmune SA, Plan-les-Ouates, Switzerland
| | - E van Poelgeest
- Center for Human Drug Research (CHDR), Leiden, The Netherlands
| | | | - K de Graaf
- Novimmune SA, Plan-les-Ouates, Switzerland
| | - J Reijers
- Center for Human Drug Research (CHDR), Leiden, The Netherlands
| | - M Moerland
- Center for Human Drug Research (CHDR), Leiden, The Netherlands
| | - J Burggraaf
- Center for Human Drug Research (CHDR), Leiden, The Netherlands
| | - C de Min
- Novimmune SA, Plan-les-Ouates, Switzerland
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71
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Liu X, Dong T, Zhou Y, Huang N, Lei X. Exploring the Binding Proteins of Glycolipids with Bifunctional Chemical Probes. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201608827] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Xiaohui Liu
- School of Pharmaceutical Science and Technology; Tianjin University; Tianjin 300072 China
| | - Ting Dong
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences; Peking University; Beijing 100871 China
| | - Yu Zhou
- National Institute of Biological Sciences (NIBS); Changping District Beijing 102206 China
| | - Niu Huang
- National Institute of Biological Sciences (NIBS); Changping District Beijing 102206 China
| | - Xiaoguang Lei
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences; Peking University; Beijing 100871 China
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72
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Liu X, Dong T, Zhou Y, Huang N, Lei X. Exploring the Binding Proteins of Glycolipids with Bifunctional Chemical Probes. Angew Chem Int Ed Engl 2016; 55:14330-14334. [DOI: 10.1002/anie.201608827] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Indexed: 01/06/2023]
Affiliation(s)
- Xiaohui Liu
- School of Pharmaceutical Science and Technology; Tianjin University; Tianjin 300072 China
| | - Ting Dong
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences; Peking University; Beijing 100871 China
| | - Yu Zhou
- National Institute of Biological Sciences (NIBS); Changping District Beijing 102206 China
| | - Niu Huang
- National Institute of Biological Sciences (NIBS); Changping District Beijing 102206 China
| | - Xiaoguang Lei
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences; Peking University; Beijing 100871 China
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73
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Billod JM, Lacetera A, Guzmán-Caldentey J, Martín-Santamaría S. Computational Approaches to Toll-Like Receptor 4 Modulation. Molecules 2016; 21:molecules21080994. [PMID: 27483231 PMCID: PMC6274477 DOI: 10.3390/molecules21080994] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/22/2016] [Accepted: 07/22/2016] [Indexed: 01/07/2023] Open
Abstract
Toll-like receptor 4 (TLR4), along with its accessory protein myeloid differentiation factor 2 (MD-2), builds a heterodimeric complex that specifically recognizes lipopolysaccharides (LPS), which are present on the cell wall of Gram-negative bacteria, activating the innate immune response. Some TLR4 modulators are undergoing preclinical and clinical evaluation for the treatment of sepsis, inflammatory diseases, cancer and rheumatoid arthritis. Since the relatively recent elucidation of the X-ray crystallographic structure of the extracellular domain of TLR4, research around this fascinating receptor has risen to a new level, and thus, new perspectives have been opened. In particular, diverse computational techniques have been applied to decipher some of the basis at the atomic level regarding the mechanism of functioning and the ligand recognition processes involving the TLR4/MD-2 system at the atomic level. This review summarizes the reported molecular modeling and computational studies that have recently provided insights into the mechanism regulating the activation/inactivation of the TLR4/MD-2 system receptor and the key interactions modulating the molecular recognition process by agonist and antagonist ligands. These studies have contributed to the design and the discovery of novel small molecules with promising activity as TLR4 modulators.
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Affiliation(s)
| | | | - Joan Guzmán-Caldentey
- Department of Chemical & Physical Biology, Centro de Investigaciones Biológicas, CIB-CSIC, C/Ramiro de Maeztu 9, 28040 Madrid, Spain.
| | - Sonsoles Martín-Santamaría
- Department of Chemical & Physical Biology, Centro de Investigaciones Biológicas, CIB-CSIC, C/Ramiro de Maeztu 9, 28040 Madrid, Spain.
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74
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Gaikwad S, Naveen C, Agrawal-Rajput R. Toll-like receptor-4 antagonism mediates benefits during neuroinflammation. Neural Regen Res 2016; 11:552-3. [PMID: 27212907 PMCID: PMC4870903 DOI: 10.4103/1673-5374.180732] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Sagar Gaikwad
- Laboratory of Immunology, School of Biological Sciences and Biotechnology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, India
| | - Challagundla Naveen
- Laboratory of Immunology, School of Biological Sciences and Biotechnology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, India
| | - Reena Agrawal-Rajput
- Laboratory of Immunology, School of Biological Sciences and Biotechnology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, India
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75
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Lewis AJ, Billiar TR, Rosengart MR. Biology and Metabolism of Sepsis: Innate Immunity, Bioenergetics, and Autophagy. Surg Infect (Larchmt) 2016; 17:286-93. [PMID: 27093228 DOI: 10.1089/sur.2015.262] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Sepsis is a complex, heterogeneous physiologic condition that represents a significant public health concern. While many insights into the pathophysiology of sepsis have been elucidated over the past decades of research, important questions remain. This article serves as a review of several important areas in sepsis research. Understanding the innate immune response has been at the forefront as of late, especially in the context of cytokine-directed therapeutic trials. Cellular bioenergetic changes provide insight into the development of organ dysfunction in sepsis. Autophagy and mitophagy perform crucial cell housekeeping and stress response functions. Finally, age-related changes and their potential impact on the septic response are reviewed.
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Affiliation(s)
- Anthony J Lewis
- Department of Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
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76
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Ciaramelli C, Calabrese V, Sestito SE, Pérez-Regidor L, Klett J, Oblak A, Jerala R, Piazza M, Martín-Santamaría S, Peri F. Glycolipid-based TLR4 Modulators and Fluorescent Probes: Rational Design, Synthesis, and Biological Properties. Chem Biol Drug Des 2016; 88:217-29. [PMID: 26896420 DOI: 10.1111/cbdd.12749] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Revised: 12/08/2015] [Accepted: 02/08/2016] [Indexed: 12/13/2022]
Abstract
The cationic glycolipid IAXO-102, a potent TLR4 antagonist targeting both MD-2 and CD14 co-receptors, has been used as scaffold to design new potential TLR4 modulators and fluorescent labels for the TLR4 receptor complex (membrane TLR4.MD-2 dimer and CD14). The primary amino group of IAXO-102, not involved in direct interaction with MD-2 and CD14 receptors, has been exploited to covalently attach a fluorescein (molecules 1 and 2) or to link two molecules of IAXO-102 through diamine and diammonium spacers, obtaining 'dimeric' molecules 3 and 4. The structure-based rational design of compounds 1-4 was guided by the optimization of MD-2 and CD14 binding. Compounds 1 and 2 inhibited TLR4 activation, in a concentration-dependent manner, and signaling in HEK-Blue TLR4 cells. The fluorescent labeling of murine macrophages by molecule 1 was inhibited by LPS and was also abrogated when cell surface proteins were digested by trypsin, thus suggesting an interaction of fluorescent probe 1 with membrane proteins of the TLR4 receptor system.
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Affiliation(s)
- Carlotta Ciaramelli
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milano, Italy
| | - Valentina Calabrese
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milano, Italy
| | - Stefania E Sestito
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milano, Italy
| | - Lucia Pérez-Regidor
- Department of Chemistry and Biochemistry, Universidad CEU San Pablo, 28668-Boadilla del Monte, Madrid, Spain.,Department of Chemical and Physical Biology, Center for Biological Research, CIB-CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Javier Klett
- Department of Chemistry and Biochemistry, Universidad CEU San Pablo, 28668-Boadilla del Monte, Madrid, Spain.,Department of Chemical and Physical Biology, Center for Biological Research, CIB-CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Alja Oblak
- Department of Biotechnology, National Institute of Chemistry Ljubljana and EN-FIST Center of Excellence, Hajdrihova 19, SI-1001, Ljubljana, Slovenia
| | - Roman Jerala
- Department of Biotechnology, National Institute of Chemistry Ljubljana and EN-FIST Center of Excellence, Hajdrihova 19, SI-1001, Ljubljana, Slovenia
| | - Matteo Piazza
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milano, Italy
| | - Sonsoles Martín-Santamaría
- Department of Chemistry and Biochemistry, Universidad CEU San Pablo, 28668-Boadilla del Monte, Madrid, Spain.,Department of Chemical and Physical Biology, Center for Biological Research, CIB-CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Francesco Peri
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milano, Italy
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Yamamoto H, Oda M, Kanno M, Tamashiro S, Tamura I, Yoneda T, Yamasaki N, Domon H, Nakano M, Takahashi H, Terao Y, Kasai Y, Imagawa H. Chemical Hybridization of Vizantin and Lipid A to Generate a Novel LPS Antagonist. Chem Pharm Bull (Tokyo) 2016; 64:246-57. [DOI: 10.1248/cpb.c15-00828] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Masataka Oda
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences
| | - Marina Kanno
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University
| | - Shota Tamashiro
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University
| | - Ikuko Tamura
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University
| | | | - Naoto Yamasaki
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University
| | - Hisanori Domon
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences
| | - Mayo Nakano
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University
| | | | - Yutaka Terao
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences
| | - Yusuke Kasai
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University
| | - Hiroshi Imagawa
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University
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78
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Balancing Innate Immunity and Inflammatory State via Modulation of Neutrophil Function: A Novel Strategy to Fight Sepsis. J Immunol Res 2015; 2015:187048. [PMID: 26798659 PMCID: PMC4699010 DOI: 10.1155/2015/187048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Revised: 11/16/2015] [Accepted: 12/02/2015] [Indexed: 12/29/2022] Open
Abstract
Sepsis and SIRS (systemic inflammatory response syndrome) belong to a severe disease complex characterized by infection and/or a whole-body inflammatory state. There is a growing body of evidence that neutrophils are actively involved in sepsis and are responsible for both release of cytokines and phagocytosis of pathogens. The neutrophil level is mainly regulated by G-CSF, a cytokine and drug, which is widely used in the septic patient with neutropenia. This review will briefly summarize the role of neutrophils and the therapeutic effect of G-CSF in sepsis. We further suggest that targeting neutrophil function to modulate the balance between innate immunity and inflammatory injury could be a worthwhile therapeutic strategy for sepsis.
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79
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Wang Y, Shan X, Chen G, Jiang L, Wang Z, Fang Q, Liu X, Wang J, Zhang Y, Wu W, Liang G. MD-2 as the target of a novel small molecule, L6H21, in the attenuation of LPS-induced inflammatory response and sepsis. Br J Pharmacol 2015; 172:4391-405. [PMID: 26076332 DOI: 10.1111/bph.13221] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 05/27/2015] [Accepted: 06/06/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE Myeloid differentiation 2 (MD-2) recognizes LPS, which is required for TLR4 activation, and represents an attractive therapeutic target for severe inflammatory disorders. We previously found that a chalcone derivative, L6H21, could inhibit LPS-induced overexpression of TNF-α and IL-6 in macrophages. Here, we performed a series of biochemical experiments to investigate whether L6H21 specifically targets MD-2 and inhibits the interaction and signalling transduction of LPS-TLR4/MD-2. EXPERIMENTAL APPROACH The binding affinity of L6H21 to MD-2 protein was analysed using computer docking, surface plasmon resonance analysis, elisa, fluorescence measurements and flow cytometric analysis. The effects of L6H21 on MAPK and NF-κB signalling were determined using EMSA, fluorescence staining, Western blotting and immunoprecipitation. The anti-inflammatory effects of L6H21 were confirmed using elisa and RT-qPCR in vitro. The anti-inflammatory effects of L6H21 were also evaluated in septic C57BL/6 mice. KEY RESULTS Compound L6H21 inserted into the hydrophobic region of the MD-2 pocket, forming hydrogen bonds with Arg(90) and Tyr(102) in the MD-2 pocket. In vitro, L6H21 subsequently suppressed MAPK phosphorylation, NF-κB activation and cytokine expression in macrophages stimulated by LPS. In vivo, L6H21 pretreatment improved survival, prevented lung injury, decreased serum and hepatic cytokine levels in mice subjected to LPS. In addition, mice with MD-2 gene knockout were universally protected from the effects of LPS-induced septic shock. CONCLUSIONS AND IMPLICATIONS Overall, this work demonstrated that the new chalcone derivative, L6H21, is a potential candidate for the treatment of sepsis. More importantly, the data confirmed that MD-2 is an important therapeutic target for inflammatory disorders.
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Affiliation(s)
- Yi Wang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaoou Shan
- Department of Paediatrics, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Gaozhi Chen
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Lili Jiang
- Department of Paediatrics, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zhe Wang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qilu Fang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xing Liu
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jingying Wang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yali Zhang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Wencan Wu
- Department of Orbital and Oculoplastic Surgery, The Eye Hospital of Wenzhou Medical University, Wenzhou, China
| | - Guang Liang
- Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
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Song Y, Liu X, Yue H, Ji J, Dou H, Hou Y. Anti-inflammatory effects of benzenediamine derivate FC-98 on sepsis injury in mice via suppression of JNK, NF-κB and IRF3 signaling pathways. Mol Immunol 2015; 67:183-92. [PMID: 26032013 DOI: 10.1016/j.molimm.2015.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 04/21/2015] [Accepted: 05/04/2015] [Indexed: 12/18/2022]
Abstract
FC-98, a synthesized benzenediamine derivate, was reported to regulate Toll-like receptor 9-induced activation of dendritic cells in our previous study. In this study, we evaluated the anti-inflammatory properties of FC-98 both in macrophages and in septic mouse models. By using enzyme-linked immunosorbent assay and real-time quantitative PCR, we found that FC-98 (6.25, 25 and 100μM) dose-dependently attenuated lipopolysaccharide (LPS)-induced tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and monocyte chemoattractant protein (MCP-1) productions in RAW264.7 and primary mouse peritoneal macrophages. These inhibitory effects were not due to inducing cell cytotoxicity or altering LPS binding or TLR4 expression. Subsequently, western blot, immunofluorescence and luciferase reporter assays were used to investigate the underlying mechanisms of its anti-inflammatory activities. Results showed that FC-98 blocked activation of the c-Jun N-terminal kinase (JNK), nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3) signaling pathways. In vivo, FC-98 (30 or 100mg/kg) was intraperitoneally administrated into LPS-induced or CLP-induced sepsis mice. It was observed to enhance the survival rate, inhibit pro-inflammatory mediator production, improve organ injuries and suppress bacterial propagation. In conclusion, FC-98 effectively inhibited macrophage inflammatory responses and ameliorated sepsis in mice through down-regulation of both MyD88 and TRIF-dependent pathways. These results suggest that FC-98 could be a promising therapeutic agent for inflammatory diseases.
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Affiliation(s)
- Yuxian Song
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing 210093, China
| | - Xianqin Liu
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing 210093, China; Biothera Solutions, formerly as Sinoasis Pharma, Ltd., Guangzhou, China
| | - Huimin Yue
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing 210093, China
| | - Jianjian Ji
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing 210093, China
| | - Huan Dou
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing 210093, China.
| | - Yayi Hou
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing 210093, China.
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81
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Wang Y, Shan X, Dai Y, Jiang L, Chen G, Zhang Y, Wang Z, Dong L, Wu J, Guo G, Liang G. Curcumin Analog L48H37 Prevents Lipopolysaccharide-Induced TLR4 Signaling Pathway Activation and Sepsis via Targeting MD2. J Pharmacol Exp Ther 2015; 353:539-50. [DOI: 10.1124/jpet.115.222570] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 04/09/2015] [Indexed: 01/07/2023] Open
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Mcdonald KA, Huang H, Tohme S, Loughran P, Ferrero K, Billiar T, Tsung A. Toll-like receptor 4 (TLR4) antagonist eritoran tetrasodium attenuates liver ischemia and reperfusion injury through inhibition of high-mobility group box protein B1 (HMGB1) signaling. Mol Med 2015; 20:639-48. [PMID: 25375408 DOI: 10.2119/molmed.2014.00076] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 10/20/2014] [Indexed: 01/10/2023] Open
Abstract
Toll-like receptor 4 (TLR4) is ubiquitously expressed on parenchymal and immune cells of the liver and is the most studied TLR responsible for the activation of proinflammatory signaling cascades in liver ischemia and reperfusion (I/R). Since pharmacological inhibition of TLR4 during the sterile inflammatory response of I/R has not been studied, we sought to determine whether eritoran, a TLR4 antagonist trialed in sepsis, could block hepatic TLR4-mediated inflammation and end organ damage. When C57BL/6 mice were pretreated with eritoran and subjected to warm liver I/R, there was significantly less hepatocellular injury compared to control counterparts. Additionally, we found that eritoran is protective in liver I/R through inhibition of high-mobility group box protein B1 (HMGB1)-mediated inflammatory signaling. When eritoran was administered in conjunction with recombinant HMGB1 during liver I/R, there was significantly less injury, suggesting that eritoran blocks the HMGB1-TLR4 interaction. Not only does eritoran attenuate TLR4-dependent HMGB1 release in vivo, but this TLR4 antagonist also dampened HMGB1's release from hypoxic hepatocytes in vitro and thereby weakened HMGB1's activation of innate immune cells. HMGB1 signaling through TLR4 makes an important contribution to the inflammatory response seen after liver I/R. This study demonstrates that novel blockade of HMGB1 by the TLR4 antagonist eritoran leads to the amelioration of liver injury.
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Affiliation(s)
- Kerry-Ann Mcdonald
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Hai Huang
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Samer Tohme
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Patricia Loughran
- Center for Biologic Imaging, Department of Cell Biology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Kimberly Ferrero
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Timothy Billiar
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Allan Tsung
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
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83
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Tumurkhuu G, Dagvadorj J, Jones HD, Chen S, Shimada K, Crother TR, Arditi M. Alternatively spliced myeloid differentiation protein-2 inhibits TLR4-mediated lung inflammation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 194:1686-94. [PMID: 25576596 PMCID: PMC4323992 DOI: 10.4049/jimmunol.1402123] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We previously identified a novel alternatively spliced isoform of human myeloid differentiation protein-2 (MD-2s) that competitively inhibits binding of MD-2 to TLR4 in vitro. In this study, we investigated the protective role of MD-2s in LPS-induced acute lung injury by delivering intratracheally an adenovirus construct that expressed MD-2s (Ad-MD-2s). After adenovirus-mediated gene transfer, MD-2s was strongly expressed in lung epithelial cells and readily detected in bronchoalveolar lavage fluid. Compared to adenovirus serotype 5 containing an empty vector lacking a transgene control mice, Ad-MD-2s delivery resulted in significantly less LPS-induced inflammation in the lungs, including less protein leakage, cell recruitment, and expression of proinflammatory cytokines and chemokines, such as IL-6, keratinocyte chemoattractant, and MIP-2. Bronchoalveolar lavage fluid from Ad-MD-2s mice transferred into lungs of naive mice before intratracheal LPS challenge diminished proinflammatory cytokine levels. As house dust mite (HDM) sensitization is dependent on TLR4 and HDM Der p 2, a structural homolog of MD-2, we also investigated the effect of MD-2s on HDM-induced allergic airway inflammation. Ad-MD-2s given before HDM sensitization significantly inhibited subsequent allergic airway inflammation after HDM challenge, including reductions in eosinophils, goblet cell hyperplasia, and IL-5 levels. Our study indicates that the alternatively spliced short isoform of human MD-2 could be a potential therapeutic candidate to treat human diseases induced or exacerbated by TLR4 signaling, such as Gram-negative bacterial endotoxin-induced lung injury and HDM-triggered allergic lung inflammation.
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Affiliation(s)
- Gantsetseg Tumurkhuu
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA 90048; Department of Biomedical Sciences, Infectious and Immunologic Diseases Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048; and
| | - Jargalsaikhan Dagvadorj
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA 90048; Department of Biomedical Sciences, Infectious and Immunologic Diseases Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048; and
| | - Heather D Jones
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048
| | - Shuang Chen
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA 90048; Department of Biomedical Sciences, Infectious and Immunologic Diseases Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048; and
| | - Kenichi Shimada
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA 90048; Department of Biomedical Sciences, Infectious and Immunologic Diseases Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048; and
| | - Timothy R Crother
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA 90048; Department of Biomedical Sciences, Infectious and Immunologic Diseases Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048; and
| | - Moshe Arditi
- Division of Infectious Diseases and Immunology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA 90048; Department of Biomedical Sciences, Infectious and Immunologic Diseases Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048; and
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84
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Abstract
Cardiac dysfunction is a major consequence that contributes to the high mortality of trauma-hemorrhage (TH) patients. Recent evidence suggests that innate immune and inflammatory responses mediated by Toll-like receptors (TLRs) play a critical role in the pathophysiologic mechanisms of acute organ dysfunction during TH. This study investigated the role of TLR4 in cardiac dysfunction following TH. Toll-like receptor 4-deficient (TLR4-/-, n = 7/group) and age-matched wild-type (WT, n = 8/group) mice were subjected to TH that was induced by soft tissue injury and blood withdrawal from the jugular vein to a mean arterial pressure of 35 ± 5 mmHg. Cardiac function and mean arterial pressure were measured with a Millar system before, during, and after blood withdrawal. Sham surgical-operated mice served as control (WT, n = 9/group; TLR4-/-, n = 10/group). Cardiac function in WT mice was significantly reduced following TH. However, cardiac function was well preserved in TLR4-/- mice. Administration of a TLR4 antagonist (3 mg/kg) to WT mice also significantly attenuated TH-induced cardiac dysfunction. Western blot showed that either TLR4-/- or TLR4 antagonist markedly attenuated TH-induced decreases in the levels of phosphorylated-Akt in myocardium. In addition, inhibition of TLR4 attenuated TH-induced myocardial nuclear factor κB-binding activity as well as lung myeloperoxidase activity and tumor necrosis factor α production. The data indicate that TLR4 plays a central role in TH-induced cardiac dysfunction. Toll-like receptor 4 deficiency or TLR4 inhibition attenuated cardiac dysfunction following TH, which may involve activation of the phosphoinositide 3-kinase/Akt signaling and decrease in nuclear factor κB-binding activity. Toll-like receptor 4 antagonism may be a new and novel approach for the treatment and management of cardiac dysfunction in TH patients.
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85
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Molecular simplification of lipid A structure: TLR4-modulating cationic and anionic amphiphiles. Mol Immunol 2015; 63:153-61. [DOI: 10.1016/j.molimm.2014.05.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/26/2014] [Accepted: 05/26/2014] [Indexed: 12/13/2022]
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86
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Yuki K, Murakami N. Sepsis pathophysiology and anesthetic consideration. Cardiovasc Hematol Disord Drug Targets 2015; 15:57-69. [PMID: 25567335 PMCID: PMC4704087 DOI: 10.2174/1871529x15666150108114810] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 09/22/2014] [Accepted: 10/11/2014] [Indexed: 12/28/2022]
Abstract
Sepsis remains to be a significant health care issue associated with high mortality and healthcare cost, despite the extensive effort to better understand the pathophysiology of the sepsis. Recently updated clinical guideline for severe sepsis and septic shock, "Surviving Sepsis Campaign 2012", emphasizes the importance of early goal-directed therapy, which can be implemented in intraoperative management of sepsis patients. Herein, we review the updates of current guideline and discuss its application to anesthesic management. Furthermore, we review the recent advance in knowledge of sepsis pathophysiology, focusing on immune modulation, which may lead to new clinical therapeutic approach to sepsis.
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Affiliation(s)
- Koichi Yuki
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
| | - Naoka Murakami
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
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87
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Gómez R, Villalvilla A, Largo R, Gualillo O, Herrero-Beaumont G. TLR4 signalling in osteoarthritis—finding targets for candidate DMOADs. Nat Rev Rheumatol 2014; 11:159-70. [DOI: 10.1038/nrrheum.2014.209] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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88
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Bahraoui E, Briant L, Chazal N. E5564 inhibits immunosuppressive cytokine IL-10 induction promoted by HIV-1 Tat protein. Virol J 2014; 11:214. [PMID: 25471526 PMCID: PMC4267154 DOI: 10.1186/s12985-014-0214-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 11/24/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In HIV-1 infected patients, production of interleukin-10 (IL-10), a highly immunosuppressive cytokine, is associated with progression of infection toward AIDS. HIV-1 Tat protein, by interacting with TLR4-MD2 at the membrane level, induces IL-10 production by primary human monocytes and macrophages. In the present study we evaluated the effect of the TLR4 antagonist Eritoran tetrasodium (E5564) on HIV-1 Tat-induced IL-10 production. FINDINGS Here, we confirm that the recombinant HIV-1 Tat protein and the GST-Tat 1-45 fusion protein efficiently stimulate IL-10 production by primary monocytes and macrophages and that this stimulation is inhibited by blocking anti-TLR4 mAbs. We show that a similar inhibition is observed by preincubating the cells with the TLR4 antagonist E5564. CONCLUSION This study provides compelling data showing for the first time that the TLR4 antagonist E5564 inhibits the immunosuppressive cytokine IL-10 production by primary human monocytes and macrophages incubated in the presence of HIV-1 Tat protein.
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Affiliation(s)
- Elmostafa Bahraoui
- Université Paul Sabatier, EA 3038, 118 Route de Narbonne, 31062, Toulouse, France. .,INSERM, U1043, CPTP, CHU Purpan, BP3028, 31024, Toulouse, Cedex 3, France. .,CNRS, U5282, CPTP, CHU Purpan, BP3028, 31024, Toulouse, Cedex3, France.
| | - Laurence Briant
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), UMR5236, CNRS - Université Montpellier 1-Montpellier 2, Montpellier, France.
| | - Nathalie Chazal
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), UMR5236, CNRS - Université Montpellier 1-Montpellier 2, Montpellier, France.
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89
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Oda M, Yamamoto H, Shibutani M, Nakano M, Yabiku K, Tarui T, Kameyama N, Shirakawa D, Obayashi S, Watanabe N, Nakase H, Suenaga M, Matsunaga Y, Nagahama M, Takahashi H, Imagawa H, Kurosawa M, Terao Y, Nishizawa M, Sakurai J. Vizantin inhibits endotoxin-mediated immune responses via the TLR 4/MD-2 complex. THE JOURNAL OF IMMUNOLOGY 2014; 193:4507-14. [PMID: 25261480 DOI: 10.4049/jimmunol.1401796] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Vizantin has immunostimulating properties and anticancer activity. In this study, we investigated the molecular mechanism of immune activation by vizantin. THP-1 cells treated with small interfering RNA for TLR-4 abolished vizantin-induced macrophage activation processes such as chemokine release. In addition, compared with wild-type mice, the release of MIP-1β induced by vizantin in vivo was significantly decreased in TLR-4 knockout mice, but not in TLR-2 knockout mice. Vizantin induced the release of IL-8 when HEK293T cells were transiently cotransfected with TLR-4 and MD-2, but not when they were transfected with TLR-4 or MD-2 alone or with TLR-2 or TLR-2/MD-2. A dipyrromethene boron difluoride-conjugated vizantin colocalized with TLR-4/MD-2, but not with TLR-4 or MD-2 alone. A pull-down assay with vizantin-coated magnetic beads showed that vizantin bound to TLR-4/MD-2 in extracts from HEK293T cells expressing both TLR-4 and MD-2. Furthermore, vizantin blocked the LPS-induced release of TNF-α and IL-1β and inhibited death in mice. We also performed in silico docking simulation analysis of vizantin and MD-2 based on the structure of MD-2 complexed with the LPS antagonist E5564; the results suggested that vizantin could bind to the active pocket of MD-2. Our observations show that vizantin specifically binds to the TLR-4/MD-2 complex and that the vizantin receptor is identical to the LPS receptor. We conclude that vizantin could be an effective adjuvant and a therapeutic agent in the treatment of infectious diseases and the endotoxin shock caused by LPS.
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Affiliation(s)
- Masataka Oda
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan; Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan
| | - Hirofumi Yamamoto
- Department of Chemistry and Functional Molecule, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Masahiro Shibutani
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Mayo Nakano
- Department of Chemistry and Functional Molecule, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Kenta Yabiku
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Takafumi Tarui
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Naoya Kameyama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Daiki Shirakawa
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Sumiyo Obayashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Naoyuki Watanabe
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Hiroshi Nakase
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Midori Suenaga
- Department of Medical Pharmacology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan; and
| | - Yoichi Matsunaga
- Department of Medical Pharmacology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan; and
| | - Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Hironobu Takahashi
- Institute of Pharmacognosy, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Hiroshi Imagawa
- Department of Chemistry and Functional Molecule, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Mie Kurosawa
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan
| | - Yutaka Terao
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan
| | - Mugio Nishizawa
- Department of Chemistry and Functional Molecule, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Jun Sakurai
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan;
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90
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The molecular mechanism of species-specific recognition of lipopolysaccharides by the MD-2/TLR4 receptor complex. Mol Immunol 2014; 63:134-42. [PMID: 25037631 DOI: 10.1016/j.molimm.2014.06.034] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/20/2014] [Accepted: 06/25/2014] [Indexed: 01/17/2023]
Abstract
Lipid A, a component of bacterial lipopolysaccharide, is a conserved microbe-associated molecular pattern that activates the MD-2/TLR4 receptor complex. Nevertheless, bacteria produce lipid A molecules of considerable structural diversity. The human MD-2/TLR4 receptor most efficiently recognizes hexaacylated bisphosphorylated lipid A produced by enterobacteria, but in some animal species the immune response can be elicited also by alternative lipid A varieties, such as tetraacylated lipid IVa or pentaacylated lipid A of Rhodobacter spheroides. Several crystal structures revealed that hexaacylated lipid A and tetraacylated lipid IVa activate the murine MD-2/TLR4 in a similar manner, but failed to explain the antagonistic vs. agonistic activity of lipid IVa in the human vs. equine receptor, respectively. Targeted mutagenesis studies of the receptor complex revealed intricate combination of electrostatic and hydrophobic interactions primarily within the MD-2 co-receptor, but with a contribution of TLR4 as well, that contribute to species-specific recognition of lipid A. We will review current knowledge regarding lipid A diversity and species-specific activation of the MD-2/TLR4 receptor complex in different species (e.g. human, mouse or equine) by lipid A varieties.
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91
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Menghini R, Campia U, Tesauro M, Marino A, Rovella V, Rodia G, Schinzari F, Tolusso B, di Daniele N, Federici M, Zoli A, Ferraccioli G, Cardillo C. Toll-like receptor 4 mediates endothelial cell activation through NF-κB but is not associated with endothelial dysfunction in patients with rheumatoid arthritis. PLoS One 2014; 9:e99053. [PMID: 24918924 PMCID: PMC4053330 DOI: 10.1371/journal.pone.0099053] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 05/09/2014] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE To investigate the effects of TLR4 antagonism on human endothelial cells activation and cytokine expression, and whether the Asp299Gly TLR4 polymorphism is associated with better endothelial function in patients with rheumatoid arthritis (RA). METHODS Human aortic endothelial cells (HAECs) were treated with lipopolysaccharide (LPS), OxPAPC, and free fatty acids (FFA) at baseline and after incubation with the TLR4 antagonist eritoran (E5564). Cytokine expression was assessed by quantitative real-time PCR. In vivo endothelial function was assessed as brachial artery flow-mediated dilation (FMD) in RA patients with the wild type gene (aa) and with the Asp299Gly TLR4 polymorphic variant (ag). RESULTS In HAEC, TLR4 antagonism with eritoran inhibited LPS-induced mRNA expression of IL-6, IL-8, TNFα, CCL-2, VCAM and ICAM (P<0.05 for all) and inhibited Ox-PAPC-induced mRNA expression of IL-8 (P<0.05) and IL-6, albeit not to a statistically significant level (p = 0.07). In contrast, eritoran did not affect FFA-induced mRNA expression of IL-6 (P>0.05). In 30 patients with RA (15 with the ag allele) undergoing measurement of FMD, no differences in FMD and plasma levels of IL-6, IL-8, VCAM, and ICAM were found between the aa and the ag phenotype (P>0.05 for all). CONCLUSIONS TLR4 signaling in endothelial cells may be triggered by LPS and oxidized phospholipids, leading to endothelial activation and inflammation, which are inhibited by eritoran. Our in vivo investigation, however, does not support an association between the Asp299Gly TLR4 polymorphism and improved endothelium-dependent vasodilator function in patients with RA. Further study is needed to better understand the potential role of TLR4 on endothelial dysfunction in this and other patient populations.
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Affiliation(s)
- Rossella Menghini
- Department of System Medicine, University of Tor Vergata, Rome, Italy
| | - Umberto Campia
- Division of Cardiology, MedStar Heart Institute, Washington, DC, United States of America
| | - Manfredi Tesauro
- Department of System Medicine, University of Tor Vergata, Rome, Italy
| | - Arianna Marino
- Department of System Medicine, University of Tor Vergata, Rome, Italy
| | - Valentina Rovella
- Department of System Medicine, University of Tor Vergata, Rome, Italy
| | - Giuseppe Rodia
- Department of System Medicine, University of Tor Vergata, Rome, Italy
| | - Francesca Schinzari
- Department of Internal Medicine, Catholic University Medical School, Rome, Italy
| | - Barbara Tolusso
- Department of Rheumatology, Catholic University Medical School, Rome, Italy
| | - Nicola di Daniele
- Department of System Medicine, University of Tor Vergata, Rome, Italy
| | - Massimo Federici
- Department of System Medicine, University of Tor Vergata, Rome, Italy
- Center for Atherosclerosis, Policlinico Tor Vergata, Rome, Italy
| | - Angelo Zoli
- Department of Rheumatology, Catholic University Medical School, Rome, Italy
| | | | - Carmine Cardillo
- Department of Internal Medicine, Catholic University Medical School, Rome, Italy
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92
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Hayashi T, Crain B, Yao S, Caneda CD, Cottam HB, Chan M, Corr M, Carson DA. Novel synthetic toll-like receptor 4/MD2 ligands attenuate sterile inflammation. J Pharmacol Exp Ther 2014; 350:330-40. [PMID: 24893985 DOI: 10.1124/jpet.114.214312] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Toll-like receptor (TLR) stimulation has been implicated as a major contributor to chronic inflammation. Among these receptors, TLR4 has been described as a key regulator of endogenous inflammation and has been proposed as a therapeutic target. Previously, we discovered by high-throughput screening a group of substituted pyrimido[5,4-b]indoles that activated a nuclear factor-κB reporter in THP-1 human monocytic cells. A biologically active hit compound was resynthesized, and derivatives were prepared to assess structure-activity relationships. The derived compounds activated cells in a TLR4/myeloid differentiation protein 2 (MD2)-dependent and CD14-independent manner, using the myeloid differentiation primary response 88 and Toll/IL-1 receptor domain-containing adapter-inducing interferon-β pathways. Two lead compounds, 1Z105 and 1Z88, were selected for further analysis based on favorable biologic properties and lack of toxicity. In vivo pharmacokinetics indicated that 1Z105 was orally bioavailable, whereas 1Z88 was not. Oral or parenteral doses of 1Z105 and 1Z88 induced undetectable or negligible levels of circulating cytokines and did not induce hepatotoxicity when administered to galactosamine-conditioned mice, indicating good safety profiles. Both compounds were very effective in preventing lethal liver damage in lipopolysaccharide treated galatosamine-conditioned mice. Orally administered 1Z105 and parenteral 1Z88 prevented arthritis in an autoantibody-driven murine model. Hence, these low molecular weight molecules that target TLR4/MD2 were well tolerated and effective in reducing target organ damage in two different mouse models of sterile inflammation.
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Affiliation(s)
- Tomoko Hayashi
- Rebecca and John Moores UCSD Cancer Center (T.H., B.C., S.Y., H.B.C., M.Ch., D.A.C.) and Department of Medicine, University of California San Diego, La Jolla, California (C.D.C., M.Co.)
| | - Brian Crain
- Rebecca and John Moores UCSD Cancer Center (T.H., B.C., S.Y., H.B.C., M.Ch., D.A.C.) and Department of Medicine, University of California San Diego, La Jolla, California (C.D.C., M.Co.)
| | - Shiyin Yao
- Rebecca and John Moores UCSD Cancer Center (T.H., B.C., S.Y., H.B.C., M.Ch., D.A.C.) and Department of Medicine, University of California San Diego, La Jolla, California (C.D.C., M.Co.)
| | - Christa D Caneda
- Rebecca and John Moores UCSD Cancer Center (T.H., B.C., S.Y., H.B.C., M.Ch., D.A.C.) and Department of Medicine, University of California San Diego, La Jolla, California (C.D.C., M.Co.)
| | - Howard B Cottam
- Rebecca and John Moores UCSD Cancer Center (T.H., B.C., S.Y., H.B.C., M.Ch., D.A.C.) and Department of Medicine, University of California San Diego, La Jolla, California (C.D.C., M.Co.)
| | - Michael Chan
- Rebecca and John Moores UCSD Cancer Center (T.H., B.C., S.Y., H.B.C., M.Ch., D.A.C.) and Department of Medicine, University of California San Diego, La Jolla, California (C.D.C., M.Co.)
| | - Maripat Corr
- Rebecca and John Moores UCSD Cancer Center (T.H., B.C., S.Y., H.B.C., M.Ch., D.A.C.) and Department of Medicine, University of California San Diego, La Jolla, California (C.D.C., M.Co.)
| | - Dennis A Carson
- Rebecca and John Moores UCSD Cancer Center (T.H., B.C., S.Y., H.B.C., M.Ch., D.A.C.) and Department of Medicine, University of California San Diego, La Jolla, California (C.D.C., M.Co.)
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93
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Chen YF, Shiau AL, Wang SH, Yang JS, Chang SJ, Wu CL, Wu TS. Zhankuic acid A isolated from Taiwanofungus camphoratus is a novel selective TLR4/MD-2 antagonist with anti-inflammatory properties. THE JOURNAL OF IMMUNOLOGY 2014; 192:2778-86. [PMID: 24532584 DOI: 10.4049/jimmunol.1301931] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
TLR4, a membrane receptor that functions in complex with its accessory protein myeloid differentiation factor-2 (MD-2), is a therapeutic target for bacterial infections. Taiwanofungus camphoratus is highly valued as a medicinal mushroom for cancer, hypertension, and inflammation in traditional medicine. Zhankuic acid A (ZAA) is the major pharmacologically active compound of T. camphoratus. The mechanism of action of T. camphoratus or ZAA has not been fully elucidated. We analyzed the structure of human TLR4/MD-2 complex with ZAA by X-score and HotLig modeling approaches. Two Abs against MD-2 were used to verify the MD-2/ZAA interaction. The inflammation and survival of the mice pretreated with ZAA and injected with LPS were monitored. The modeling structure shows that ZAA binds the MD-2 hydrophobic pocket exclusively via specific molecular recognition; the contact interface is dominated by hydrophobic interactions. Binding of ZAA to MD-2 reduced Ab recognition to native MD-2, similar to the effect of LPS binding. Furthermore, ZAA significantly ameliorated LPS-induced endotoxemia and Salmonella-induced diarrhea in mice. Our results suggest that ZAA, which can compete with LPS for binding to MD-2 as a TLR4/MD-2 antagonist, may be a potential therapeutic agent for gram-negative bacterial infections.
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Affiliation(s)
- Yu-Fon Chen
- Institute of Life Sciences, National Cheng Kung University, Tainan 70101, Taiwan
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94
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Lu P, Sodhi CP, Hackam DJ. Toll-like receptor regulation of intestinal development and inflammation in the pathogenesis of necrotizing enterocolitis. ACTA ACUST UNITED AC 2013; 21:81-93. [PMID: 24365655 DOI: 10.1016/j.pathophys.2013.11.007] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Toll-like receptors (TLRs) are a structurally related family of molecules that respond to a wide variety of endogenous and exogenous ligands, and which serve as important components of the innate immune system. While TLRs have established roles in host defense, these molecules have also been shown to play important roles in the development of various disease states. A particularly important example of the role of TLRs in disease induction includes necrotizing enterocolitis (NEC), which is the most common gastrointestinal disease in preterm infants, and which is associated with extremely high morbidity and mortality rates. The development of NEC is thought to reflect an abnormal interaction between microorganisms and the immature intestinal epithelium, and emerging evidence has clearly placed the spotlight on an important and exciting role for TLRs, particularly TLR4, in NEC pathogenesis. In premature infants, TLR4 signaling within the small intestinal epithelium regulates apoptosis, proliferation and migration of enterocytes, affects the differentiation of goblet cells, and reduces microcirculatory perfusion, which in combination result in the development of NEC. This review will explore the signaling properties of TLRs on hematopoietic and non-hematopoietic cells, and will examine the role of TLR4 signaling in the development of NEC. In addition, the effects of dampening TLR4 signaling using synthetic and endogenous TLR4 inhibitors and active components from amniotic fluid and human milk on NEC severity will be reviewed. In so doing, we hope to present a balanced approach to the understanding of the role of TLRs in both immunity and disease pathogenesis, and to dissect the precise roles for TLR4 in both the cause and therapeutic intervention of necrotizing enterocolitis.
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Affiliation(s)
- Peng Lu
- Departments of Surgery, University of Pittsburgh School of Medicine, United States
| | - Chhinder P Sodhi
- Departments of Surgery, University of Pittsburgh School of Medicine, United States; Division of Pediatric Surgery, Children's Hospital of Pittsburgh of UPMC, United States
| | - David J Hackam
- Departments of Surgery, University of Pittsburgh School of Medicine, United States; Division of Pediatric Surgery, Children's Hospital of Pittsburgh of UPMC, United States.
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95
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Wang X, Smith C, Yin H. Targeting Toll-like receptors with small molecule agents. Chem Soc Rev 2013; 42:4859-66. [PMID: 23503527 DOI: 10.1039/c3cs60039d] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Toll-like receptors (TLRs) are type I transmembrane proteins that are key regulators of both innate and adaptive immune responses. To protect the host from viral and bacterial threats, TLRs trigger a pro-inflammatory immune response by detecting pathogen and danger associated molecular patterns. Considerable evidence has accumulated to show that the dysregulation of TLR signaling contributes to the development and progression of numerous diseases. Therefore, TLRs are emerging as important drug discovery targets. Currently, there is great interest in the development of TLR small molecule modulators for interrogating TLR signaling and treating diseases caused by TLR signaling malfunctions. In this tutorial review, we will outline methods for the discovery of TLR small molecule modulators and the up-to-date progress in this field. Small molecules targeting TLRs not only provide an opportunity to identify promising drug candidates, but also unveil knowledge regarding TLR signaling pathways.
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Affiliation(s)
- Xiaohui Wang
- Department of Chemistry and Biochemistry and the BioFrontiers Institute, 596 University of Colorado at Boulder, Boulder, CO 80309-0596, USA
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96
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Recognition of lipopolysaccharide pattern by TLR4 complexes. Exp Mol Med 2013; 45:e66. [PMID: 24310172 PMCID: PMC3880462 DOI: 10.1038/emm.2013.97] [Citation(s) in RCA: 726] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 07/22/2013] [Indexed: 12/14/2022] Open
Abstract
Lipopolysaccharide (LPS) is a major component of the outer membrane of Gram-negative bacteria. Minute amounts of LPS released from infecting pathogens can initiate potent innate immune responses that prime the immune system against further infection. However, when the LPS response is not properly controlled it can lead to fatal septic shock syndrome. The common structural pattern of LPS in diverse bacterial species is recognized by a cascade of LPS receptors and accessory proteins, LPS binding protein (LBP), CD14 and the Toll-like receptor4 (TLR4)–MD-2 complex. The structures of these proteins account for how our immune system differentiates LPS molecules from structurally similar host molecules. They also provide insights useful for discovery of anti-sepsis drugs. In this review, we summarize these structures and describe the structural basis of LPS recognition by LPS receptors and accessory proteins.
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97
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Peri F, Calabrese V. Toll-like receptor 4 (TLR4) modulation by synthetic and natural compounds: an update. J Med Chem 2013; 57:3612-22. [PMID: 24188011 DOI: 10.1021/jm401006s] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Toll-like receptor 4 (TLR4), together with MD-2, binds bacterial endotoxins (E) with high affinity, triggering formation of the activated homodimer (E.MD-2.TLR4)2. Activated TLR4 induces intracellular signaling leading to activation of transcription factors that result in cytokine and chemokine production and initiation of inflammatory and immune responses. TLR4 also responds to endogenous ligands called danger associated molecular patterns (DAMPs). Increased sensitivity to infection and a variety of immune pathologies have been associated with either too little or too much TLR4 activation. We review here the molecular mechanisms of TLR4 activation (agonism) or inhibition (antagonism) by small organic molecules of both natural and synthetic origin. The role of co-receptors MD-2 and CD14 in the TLR4 modulation process is also discussed. Recent achievements in the field of chemical TLR4 modulation are reviewed, with special focus on nonclassical TLR4 ligands with a chemical structure different from that of lipid A.
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Affiliation(s)
- Francesco Peri
- Department of Biotechnology and Biosciences, University of Milano-Bicocca , Piazza della Scienza, 2, 20126 Milano, Italy
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98
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Savva A, Roger T. Targeting toll-like receptors: promising therapeutic strategies for the management of sepsis-associated pathology and infectious diseases. Front Immunol 2013; 4:387. [PMID: 24302927 PMCID: PMC3831162 DOI: 10.3389/fimmu.2013.00387] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 11/05/2013] [Indexed: 01/04/2023] Open
Abstract
Toll-like receptors (TLRs) are pattern recognition receptors playing a fundamental role in sensing microbial invasion and initiating innate and adaptive immune responses. TLRs are also triggered by danger signals released by injured or stressed cells during sepsis. Here we focus on studies developing TLR agonists and antagonists for the treatment of infectious diseases and sepsis. Positioned at the cell surface, TLR4 is essential for sensing lipopolysaccharide of Gram-negative bacteria, TLR2 is involved in the recognition of a large panel of microbial ligands, while TLR5 recognizes flagellin. Endosomal TLR3, TLR7, TLR8, TLR9 are specialized in the sensing of nucleic acids produced notably during viral infections. TLR4 and TLR2 are favorite targets for developing anti-sepsis drugs, and antagonistic compounds have shown efficient protection from septic shock in pre-clinical models. Results from clinical trials evaluating anti-TLR4 and anti-TLR2 approaches are presented, discussing the challenges of study design in sepsis and future exploitation of these agents in infectious diseases. We also report results from studies suggesting that the TLR5 agonist flagellin may protect from infections of the gastrointestinal tract and that agonists of endosomal TLRs are very promising for treating chronic viral infections. Altogether, TLR-targeted therapies have a strong potential for prevention and intervention in infectious diseases, notably sepsis.
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Affiliation(s)
- Athina Savva
- Infectious Diseases Service, Department of Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne , Lausanne , Switzerland
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99
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Artner D, Oblak A, Ittig S, Garate JA, Horvat S, Arrieumerlou C, Hofinger A, Oostenbrink C, Jerala R, Kosma P, Zamyatina A. Conformationally constrained lipid A mimetics for exploration of structural basis of TLR4/MD-2 activation by lipopolysaccharide. ACS Chem Biol 2013; 8:2423-32. [PMID: 23952219 PMCID: PMC3833292 DOI: 10.1021/cb4003199] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recognition of the lipopolysaccharide (LPS), a major component of the outer membrane of Gram-negative bacteria, by the Toll-like receptor 4 (TLR4)-myeloid differentiation factor 2 (MD-2) complex is essential for the control of bacterial infection. A pro-inflammatory signaling cascade is initiated upon binding of membrane-associated portion of LPS, a glycophospholipid Lipid A, by a coreceptor protein MD-2, which results in a protective host innate immune response. However, activation of TLR4 signaling by LPS may lead to the dysregulated immune response resulting in a variety of inflammatory conditions including sepsis syndrome. Understanding of structural requirements for Lipid A endotoxicity would ensure the development of effective anti-inflammatory medications. Herein, we report on design, synthesis, and biological activities of a series of conformationally confined Lipid A mimetics based on β,α-trehalose-type scaffold. Replacement of the flexible three-bond β(1→6) linkage in diglucosamine backbone of Lipid A by a two-bond β,α(1↔1) glycosidic linkage afforded novel potent TLR4 antagonists. Synthetic tetraacylated bisphosphorylated Lipid A mimetics based on a β-GlcN(1↔1)α-GlcN scaffold selectively block the LPS binding site on both human and murine MD-2 and completely abolish lipopolysaccharide-induced pro-inflammatory signaling, thereby serving as antisepsis drug candidates. In contrast to their natural counterpart lipid IVa, conformationally constrained Lipid A mimetics do not activate mouse TLR4. The structural basis for high antagonistic activity of novel Lipid A mimetics was confirmed by molecular dynamics simulation. Our findings suggest that besides the chemical structure, also the three-dimensional arrangement of the diglucosamine backbone of MD-2-bound Lipid A determines endotoxic effects on TLR4.
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Affiliation(s)
- Daniel Artner
- Department
of Chemistry, University of Natural Resources and Life Sciences, Muthgasse
18, A-1190 Vienna, Austria
| | - Alja Oblak
- Department
of Biotechnology, National Institute of Chemistry, University of Ljubljana, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Simon Ittig
- Biozentrum University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Jose Antonio Garate
- Institute
of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Simon Horvat
- Department
of Biotechnology, National Institute of Chemistry, University of Ljubljana, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Cécile Arrieumerlou
- Biozentrum University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Andreas Hofinger
- Department
of Chemistry, University of Natural Resources and Life Sciences, Muthgasse
18, A-1190 Vienna, Austria
| | - Chris Oostenbrink
- Institute
of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Roman Jerala
- Department
of Biotechnology, National Institute of Chemistry, University of Ljubljana, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Paul Kosma
- Department
of Chemistry, University of Natural Resources and Life Sciences, Muthgasse
18, A-1190 Vienna, Austria
| | - Alla Zamyatina
- Department
of Chemistry, University of Natural Resources and Life Sciences, Muthgasse
18, A-1190 Vienna, Austria
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100
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Ramezani A, Raj DS. The gut microbiome, kidney disease, and targeted interventions. J Am Soc Nephrol 2013; 25:657-70. [PMID: 24231662 DOI: 10.1681/asn.2013080905] [Citation(s) in RCA: 479] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The human gut harbors >100 trillion microbial cells, which influence the nutrition, metabolism, physiology, and immune function of the host. Here, we review the quantitative and qualitative changes in gut microbiota of patients with CKD that lead to disturbance of this symbiotic relationship, how this may contribute to the progression of CKD, and targeted interventions to re-establish symbiosis. Endotoxin derived from gut bacteria incites a powerful inflammatory response in the host organism. Furthermore, protein fermentation by gut microbiota generates myriad toxic metabolites, including p-cresol and indoxyl sulfate. Disruption of gut barrier function in CKD allows translocation of endotoxin and bacterial metabolites to the systemic circulation, which contributes to uremic toxicity, inflammation, progression of CKD, and associated cardiovascular disease. Several targeted interventions that aim to re-establish intestinal symbiosis, neutralize bacterial endotoxins, or adsorb gut-derived uremic toxins have been developed. Indeed, animal and human studies suggest that prebiotics and probiotics may have therapeutic roles in maintaining a metabolically-balanced gut microbiota and reducing progression of CKD and uremia-associated complications. We propose that further research should focus on using this highly efficient metabolic machinery to alleviate uremic symptoms.
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Affiliation(s)
- Ali Ramezani
- Division of Renal Diseases and Hypertension, The George Washington University, Washington DC
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