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Savulescu-Fiedler I, Mihalcea R, Dragosloveanu S, Scheau C, Baz RO, Caruntu A, Scheau AE, Caruntu C, Benea SN. The Interplay between Obesity and Inflammation. Life (Basel) 2024; 14:856. [PMID: 39063610 PMCID: PMC11277997 DOI: 10.3390/life14070856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/01/2024] [Accepted: 07/05/2024] [Indexed: 07/28/2024] Open
Abstract
Obesity is an important condition affecting the quality of life of numerous patients and increasing their associated risk for multiple diseases, including tumors and immune-mediated disorders. Inflammation appears to play a major role in the development of obesity and represents a central point for the activity of cellular and humoral components in the adipose tissue. Macrophages play a key role as the main cellular component of the adipose tissue regulating the chronic inflammation and modulating the secretion and differentiation of various pro- and anti-inflammatory cytokines. Inflammation also involves a series of signaling pathways that might represent the focus for new therapies and interventions. Weight loss is essential in decreasing cardiometabolic risks and the degree of associated inflammation; however, the latter can persist for long after the excess weight is lost, and can involve changes in macrophage phenotypes that can ensure the metabolic adjustment. A clear understanding of the pathophysiological processes in the adipose tissue and the interplay between obesity and chronic inflammation can lead to a better understanding of the development of comorbidities and may ensure future targets for the treatment of obesity.
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Affiliation(s)
- Ilinca Savulescu-Fiedler
- Department of Internal Medicine, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Department of Internal Medicine and Cardiology, Coltea Clinical Hospital, 030167 Bucharest, Romania
| | - Razvan Mihalcea
- Department of Internal Medicine and Cardiology, Coltea Clinical Hospital, 030167 Bucharest, Romania
| | - Serban Dragosloveanu
- Department of Orthopaedics, “Foisor” Clinical Hospital of Orthopaedics, Traumatology and Osteoarticular TB, 021382 Bucharest, Romania
- Department of Orthopaedics and Traumatology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Cristian Scheau
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania (C.C.)
- Department of Radiology and Medical Imaging, “Foisor” Clinical Hospital of Orthopaedics, Traumatology and Osteoarticular TB, 030167 Bucharest, Romania
| | - Radu Octavian Baz
- Clinical Laboratory of Radiology and Medical Imaging, “Sf. Apostol Andrei” County Emergency Hospital, 900591 Constanta, Romania
- Department of Radiology and Medical Imaging, Faculty of Medicine, “Ovidius” University, 900527 Constanta, Romania
| | - Ana Caruntu
- Department of Oral and Maxillofacial Surgery, “Carol Davila” Central Military Emergency Hospital, 010825 Bucharest, Romania
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Titu Maiorescu” University, 031593 Bucharest, Romania
| | - Andreea-Elena Scheau
- Department of Radiology and Medical Imaging, Fundeni Clinical Institute, 022328 Bucharest, Romania
| | - Constantin Caruntu
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania (C.C.)
- Department of Dermatology, “Prof. N.C. Paulescu” National Institute of Diabetes, Nutrition and Metabolic Diseases, 011233 Bucharest, Romania
| | - Serban Nicolae Benea
- Department of Infectious Diseases, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- “Prof. Dr. Matei Balș” National Institute for Infectious Diseases, 021105 Bucharest, Romania
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Wang P, Yang X, Zhang L, Sha S, Huang J, Peng J, Gu J, Pearson JA, Hu Y, Zhao H, Wong FS, Wang Q, Wen L. Tlr9 deficiency in B cells leads to obesity by promoting inflammation and gut dysbiosis. Nat Commun 2024; 15:4232. [PMID: 38762479 PMCID: PMC11102548 DOI: 10.1038/s41467-024-48611-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 05/02/2024] [Indexed: 05/20/2024] Open
Abstract
Toll-like receptor 9 (TLR9) recognizes bacterial, viral and self DNA and play an important role in immunity and inflammation. However, the role of TLR9 in obesity is less well-studied. Here, we generate B-cell-specific Tlr9-deficient (Tlr9fl/fl/Cd19Cre+/-, KO) B6 mice and model obesity using a high-fat diet. Compared with control mice, B-cell-specific-Tlr9-deficient mice exhibited increased fat tissue inflammation, weight gain, and impaired glucose and insulin tolerance. Furthermore, the frequencies of IL-10-producing-B cells and marginal zone B cells were reduced, and those of follicular and germinal center B cells were increased. This was associated with increased frequencies of IFNγ-producing-T cells and increased follicular helper cells. In addition, gut microbiota from the KO mice induced a pro-inflammatory state leading to immunological and metabolic dysregulation when transferred to germ-free mice. Using 16 S rRNA gene sequencing, we identify altered gut microbial communities including reduced Lachnospiraceae, which may play a role in altered metabolism in KO mice. We identify an important network involving Tlr9, Irf4 and Il-10 interconnecting metabolic homeostasis, with the function of B and T cells, and gut microbiota in obesity.
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Affiliation(s)
- Pai Wang
- Department of Gastrocolorectal Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Xin Yang
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Luyao Zhang
- Department of Gastrocolorectal Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Sha Sha
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
- Department of Nephrology, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong, China
| | - Juan Huang
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Jian Peng
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Jianlei Gu
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
| | - James Alexander Pearson
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
- Division of Infection and Immunity, School of Medicine and Systems Immunity University Research Institute, Cardiff University, Cardiff, UK
| | - Youjia Hu
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Hongyu Zhao
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
| | - F Susan Wong
- Division of Infection and Immunity, School of Medicine and Systems Immunity University Research Institute, Cardiff University, Cardiff, UK
| | - Quan Wang
- Department of Gastrocolorectal Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China.
| | - Li Wen
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA.
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Abramov VM, Kosarev IV, Machulin AV, Deryusheva EI, Priputnevich TV, Panin AN, Chikileva IO, Abashina TN, Manoyan AM, Akhmetzyanova AA, Blumenkrants DA, Ivanova OE, Papazyan TT, Nikonov IN, Suzina NE, Melnikov VG, Khlebnikov VS, Sakulin VK, Samoilenko VA, Gordeev AB, Sukhikh GT, Uversky VN, Karlyshev AV. Anti- Salmonella Defence and Intestinal Homeostatic Maintenance In Vitro of a Consortium Containing Limosilactobacillus fermentum 3872 and Ligilactobacillus salivarius 7247 Strains in Human, Porcine, and Chicken Enterocytes. Antibiotics (Basel) 2023; 13:30. [PMID: 38247590 PMCID: PMC10812507 DOI: 10.3390/antibiotics13010030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/18/2023] [Accepted: 12/22/2023] [Indexed: 01/23/2024] Open
Abstract
Limosilactobacillus fermentum strain 3872 (LF3872) was originally isolated from the breast milk of a healthy woman during lactation and the breastfeeding of a child. Ligilactobacillus salivarius strain 7247 (LS7247) was isolated at the same time from the intestines and reproductive system of a healthy woman. The genomes of these strains contain genes responsible for the production of peptidoglycan-degrading enzymes and factors that increase the permeability of the outer membrane of Gram-negative pathogens. In this work, the anti-Salmonella and intestinal homeostatic features of the LF3872 and LS7247 consortium were studied. A multi-drug resistant (MDR) strain of Salmonella enteritidis (SE) was used in the experiments. The consortium effectively inhibited the adhesion of SE to intact and activated human, porcine, and chicken enterocytes and reduced invasion. The consortium had a bactericidal effect on SE in 6 h of co-culturing. A gene expression analysis of SE showed that the cell-free supernatant (CFS) of the consortium inhibited the expression of virulence genes critical for the colonization of human and animal enterocytes. The CFS stimulated the production of an intestinal homeostatic factor-intestinal alkaline phosphatase (IAP)-in Caco-2 and HT-29 enterocytes. The consortium decreased the production of pro-inflammatory cytokines IL-8, TNF-α, and IL-1β, and TLR4 mRNA expression in human and animal enterocytes. It stimulated the expression of TLR9 in human and porcine enterocytes and stimulated the expression of TLR21 in chicken enterocytes. The consortium also protected the intestinal barrier functions through the increase of transepithelial electrical resistance (TEER) and the inhibition of paracellular permeability in the monolayers of human and animal enterocytes. The results obtained suggest that a LF3872 and LS7247 consortium can be used as an innovative feed additive to reduce the spread of MDR SE among the population and farm animals.
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Affiliation(s)
- Vyacheslav M. Abramov
- Federal Service for Veterinary and Phytosanitary Surveillance (Rosselkhoznadzor) Federal State Budgetary Institution “The Russian State Center for Animal Feed and Drug Standardization and Quality” (FGBU VGNKI), 123022 Moscow, Russia
- Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health, 117997 Moscow, Russia (A.B.G.)
| | - Igor V. Kosarev
- Federal Service for Veterinary and Phytosanitary Surveillance (Rosselkhoznadzor) Federal State Budgetary Institution “The Russian State Center for Animal Feed and Drug Standardization and Quality” (FGBU VGNKI), 123022 Moscow, Russia
- Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health, 117997 Moscow, Russia (A.B.G.)
| | - Andrey V. Machulin
- Skryabin Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Science”, Russian Academy of Science, 142290 Pushchino, Russia
| | - Evgenia I. Deryusheva
- Institute for Biological Instrumentation, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Science”, Russian Academy of Science, 142290 Pushchino, Russia
| | - Tatiana V. Priputnevich
- Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health, 117997 Moscow, Russia (A.B.G.)
| | - Alexander N. Panin
- Federal Service for Veterinary and Phytosanitary Surveillance (Rosselkhoznadzor) Federal State Budgetary Institution “The Russian State Center for Animal Feed and Drug Standardization and Quality” (FGBU VGNKI), 123022 Moscow, Russia
| | - Irina O. Chikileva
- Blokhin National Research Center of Oncology, Ministry of Health RF, 115478 Moscow, Russia
| | - Tatiana N. Abashina
- Skryabin Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Science”, Russian Academy of Science, 142290 Pushchino, Russia
| | - Ashot M. Manoyan
- Federal Service for Veterinary and Phytosanitary Surveillance (Rosselkhoznadzor) Federal State Budgetary Institution “The Russian State Center for Animal Feed and Drug Standardization and Quality” (FGBU VGNKI), 123022 Moscow, Russia
| | - Anna A. Akhmetzyanova
- Federal Service for Veterinary and Phytosanitary Surveillance (Rosselkhoznadzor) Federal State Budgetary Institution “The Russian State Center for Animal Feed and Drug Standardization and Quality” (FGBU VGNKI), 123022 Moscow, Russia
| | - Dmitriy A. Blumenkrants
- Federal Service for Veterinary and Phytosanitary Surveillance (Rosselkhoznadzor) Federal State Budgetary Institution “The Russian State Center for Animal Feed and Drug Standardization and Quality” (FGBU VGNKI), 123022 Moscow, Russia
| | - Olga E. Ivanova
- Federal Service for Veterinary and Phytosanitary Surveillance (Rosselkhoznadzor) Federal State Budgetary Institution “The Russian State Center for Animal Feed and Drug Standardization and Quality” (FGBU VGNKI), 123022 Moscow, Russia
| | | | - Ilia N. Nikonov
- Federal State Educational Institution of Higher Professional Education, Moscow State Academy of Veterinary Medicine and Biotechnology Named after K.I. Skryabin, 109472 Moscow, Russia;
| | - Nataliya E. Suzina
- Skryabin Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Science”, Russian Academy of Science, 142290 Pushchino, Russia
| | - Vyacheslav G. Melnikov
- Gabrichevsky Research Institute for Epidemiology and Microbiology, 125212 Moscow, Russia
| | | | - Vadim K. Sakulin
- Institute of Immunological Engineering, 142380 Lyubuchany, Russia; (V.S.K.); (V.K.S.)
| | - Vladimir A. Samoilenko
- Skryabin Institute of Biochemistry and Physiology of Microorganisms, Federal Research Center “Pushchino Scientific Center for Biological Research of Russian Academy of Science”, Russian Academy of Science, 142290 Pushchino, Russia
| | - Alexey B. Gordeev
- Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health, 117997 Moscow, Russia (A.B.G.)
| | - Gennady T. Sukhikh
- Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health, 117997 Moscow, Russia (A.B.G.)
| | - Vladimir N. Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA;
| | - Andrey V. Karlyshev
- Department of Biomolecular Sciences, School of Life Sciences, Chemistry and Pharmacy, Faculty of Health, Science, Social Care and Education, Kingston University London, Kingston upon Thames KT1 2EE, UK
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Tsounis EP, Aggeletopoulou I, Mouzaki A, Triantos C. Creeping Fat in the Pathogenesis of Crohn's Disease: An Orchestrator or a Silent Bystander? Inflamm Bowel Dis 2023; 29:1826-1836. [PMID: 37260352 DOI: 10.1093/ibd/izad095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Indexed: 06/02/2023]
Abstract
Although the phenomenon of hypertrophied adipose tissue surrounding inflamed bowel segments in Crohn's disease has been described since 1932, the mechanisms mediating the creeping fat formation and its role in the pathogenesis of the disease have not been fully unraveled. Recent advances demonstrating the multiple actions of adipose tissue beyond energy storage have brought creeping fat to the forefront of scientific research. In Crohn's disease, dysbiosis and transmural injury compromise the integrity of the intestinal barrier, resulting in an excessive influx of intraluminal microbiota and xenobiotics. The gut and peri-intestinal fat are in close anatomic relationship, implying a direct reciprocal immunologic relationship, whereas adipocytes are equipped with an arsenal of innate immunity sensors that respond to invading stimuli. As a result, adipocytes and their progenitor cells undergo profound immunophenotypic changes, leading to adipose tissue remodeling and eventual formation of creeping fat. Indeed, creeping fat is an immunologically active organ that synthesizes various pro- and anti-inflammatory cytokines, profibrotic mediators, and adipokines that serve as paracrine/autocrine signals and regulate immune responses. Therefore, creeping fat appears to be involved in inflammatory signaling, which explains why it has been associated with a higher severity or complicated phenotype of Crohn's disease. Interestingly, there is growing evidence for an alternative immunomodulatory function of creeping fat as a second barrier that prevents an abnormal systemic inflammatory response at the expense of an increasingly proliferating profibrotic environment. Further studies are needed to clarify how this modified adipose tissue exerts its antithetic effect during the course of Crohn's disease.
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Affiliation(s)
- Efthymios P Tsounis
- Division of Gastroenterology, Department of Internal Medicine, University Hospital of Patras, Patras 26504, Greece
| | - Ioanna Aggeletopoulou
- Division of Gastroenterology, Department of Internal Medicine, University Hospital of Patras, Patras 26504, Greece
- Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras, Greece
| | - Athanasia Mouzaki
- Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras, Greece
| | - Christos Triantos
- Division of Gastroenterology, Department of Internal Medicine, University Hospital of Patras, Patras 26504, Greece
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Höpfinger A, Schmid A, Schweitzer L, Patz M, Weber A, Schäffler A, Karrasch T. Regulation of Cathelicidin Antimicrobial Peptide (CAMP) Gene Expression by TNFα and cfDNA in Adipocytes. Int J Mol Sci 2023; 24:15820. [PMID: 37958808 PMCID: PMC10649744 DOI: 10.3390/ijms242115820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 10/16/2023] [Accepted: 10/21/2023] [Indexed: 11/15/2023] Open
Abstract
Understanding the complex interactions between metabolism and the immune system ("metaflammation") is crucial for the identification of key immunomodulatory factors as potential therapeutic targets in obesity and in cardiovascular diseases. Cathelicidin antimicrobial peptide (CAMP) is an important factor of innate immunity and is expressed in adipocytes. CAMP, therefore, might play a role as an adipokine in metaflammation and adipose inflammation. TNFα, cell-free nucleic acids (cfDNA), and toll-like receptor (TLR) 9 are components of the innate immune system and are functionally active in adipose tissue. The aim of the present study was to investigate the impact of TNFα and cfDNA on CAMP expression in adipocytes. Since cfDNA acts as a physiological TLR9 agonist, we additionally investigated TLR9-mediated CAMP regulation in adipocytes and adipose tissue. CAMP gene expression in murine 3T3-L1 and human SGBS adipocytes and in murine and human adipose tissues was quantified by real-time PCR. Adipocyte inflammation was induced in vitro by TNFα and cfDNA stimulation. Serum CAMP concentrations in TLR9 knockout (KO) and in wildtype mice were quantified by ELISA. In primary adipocytes of wildtype and TLR9 KO mice, CAMP gene expression was quantified by real-time PCR. CAMP gene expression was considerably increased in 3T3-L1 and SGBS adipocytes during differentiation. TNFα significantly induced CAMP gene expression in mature adipocytes, which was effectively antagonized by inhibition of PI3K signaling. Cell-free nucleic acids (cfDNA) significantly impaired CAMP gene expression, whereas synthetic agonistic and antagonistic TLR9 ligands had no effect. CAMP and TLR9 gene expression were correlated positively in murine and human subcutaneous but not in intra-abdominal/visceral adipose tissues. Male TLR9 knockout mice exhibited lower systemic CAMP concentrations than wildtype mice. CAMP gene expression levels in primary adipocytes did not significantly differ between wildtype and TLR9 KO mice. These findings suggest a regulatory role of inflammatory mediators, such as TNFα and cfDNA, in adipocytic CAMP expression as a novel putative molecular mechanism in adipose tissue innate immunity.
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Affiliation(s)
- Alexandra Höpfinger
- Department of Internal Medicine III, University of Giessen, 35392 Giessen, Germany (A.S.); (T.K.)
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He J, Huang F, Liao X, Zhang J, Wei S, Xiao Y, Zheng X, Zhu Z, Chen D, Chen J. TLR9 agonist CpG ODN 2395 promotes the immune response against Leishmania donovani in obesity and undernutrition mice. Acta Trop 2023; 242:106921. [PMID: 37030488 DOI: 10.1016/j.actatropica.2023.106921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/16/2023] [Accepted: 04/05/2023] [Indexed: 04/09/2023]
Abstract
As important immunomodulators, CpG ODNs have broad application prospects in the treatment and prevention of leishmaniasis. In order to explore the immunomodulatory effect of CpG ODNs on mice infected with Leishmania parasites in different nutritional status, TLR9 agonist CpG ODN 2395 or TLR9 antagonist CpG ODN 2088 was injected into normal, obesity and undernutrition BALB/c mice infected with Leishmania donovani, respectively. Subsequently, spleen and liver parasite loads, spleen and liver immune gene expression, spleen T cell subsets proportion and PD-1 expression, serum lipids, serum cytokines, and anti-Leishmania antibodies were measured to assess the immune response of mice with different nutritional status. The results displayed that at the 8th week after infection, the spleen parasite load of obesity and undernutrition mice was significantly higher than that of normal mice, but the liver parasite load showed no statistical difference among the three groups. The treatment of CpG ODN 2395 or CpG ODN 2088 significantly reduced the spleen parasite load of obesity and undernutrition infected mice, but did not reduce that of normal infected mice. In obesity infected mice, CpG ODN 2395 promoted the up-regulation of TCR, ICOS and TLR4 in spleen, promoted the secretion of IFN-γ and anti-Leishmania total IgG and IgG1 antibodies, and increased the content of serum HDL-C. In undernutrition infected mice, CpG ODN 2395 promoted the up-regulation of spleen CD28 and TLR9, increased the proportion of spleen CD3+ T cells, and decreased the content of serum IL-10. Our results demonstrated that CpG ODN 2395 enhanced the immune response and clearance of Leishmania parasites in obesity and undernutrition mice, which might be used as a therapeutic agent for obesity and undernutrition leishmaniasis patients in the future.
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Affiliation(s)
- Jinlei He
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Fan Huang
- First Surgical Department, Chengdu Shuangliu Hospital of Traditional Chinese Medicine, Chengdu, China
| | - Xuechun Liao
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Jianhui Zhang
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Shulan Wei
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Yuying Xiao
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Xiaoting Zheng
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Zheying Zhu
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Dali Chen
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China.
| | - Jianping Chen
- Department of Pathogenic Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China.
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Schäffler A. [Role of metaflammation as a systemic manifestation of metabolic diseases]. INNERE MEDIZIN (HEIDELBERG, GERMANY) 2023; 64:313-322. [PMID: 36346457 DOI: 10.1007/s00108-022-01416-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/22/2022] [Indexed: 11/09/2022]
Abstract
Visceral obesity as a component of the metabolic syndrome is characterized by systemic and local inflammation, which can be quantified in organs (metaflammation). This process can be regarded as a chronic, sterile, and low-grade state of inflammation without infection, trauma, tumor or autoimmunity. It is caused by an inflammation of the visceral adipose tissue (adipose inflammation or adipoflammation) due to adipocyte hypertrophy and hyperplasia with increased infiltration by monocytes and macrophages. Important is the presence of proinflammatory, so-called polarized M1 macrophages that are induced by interferon gamma (IFN-γ) and lipopolysaccharides (LPS) with secretion of interleukin (IL)-6, tumor necrosis factor (TNF) and IL‑1. In contrast, the anti-inflammatory, so-called polarized M2 macrophages induced by IL‑4 and IL-13 with secretion of IL‑8 and IL-10 decrease. In addition, the secreted adipokine pattern changes from anti-inflammatory to proinflammatory. Adipocyte necrosis, local hypoxia, dysregulated autophagy, activation of inflammasomes, modulation of toll-like receptors, and epigenetic factors play a complex role. This mechanism results in local insulin resistance and subsequently a systemic insulin resistance of peripheral organs as well as a spillover of local mediators of inflammation into the systemic circulation (measured as obesity C‑reactive protein, CRP). The activation of inflammatory signal transduction cascades leads to inhibitory phosphorylation of the insulin signaling pathway and a weakening of the effect of insulin. In parallel, ectopic lipid accumulation occurs in the liver, musculature, pancreas, pericardium and lungs. Diacylglycerol (DAG) activates specific isoforms of protein kinase C (ε in the liver and τ in the musculature), which in turn lead to inhibition of the insulin signaling pathway. Insulin resistance in obesity and type 2 diabetes mellitus is an inflammatory disease. The aim of future translational approaches is an anti-inflammatory, molecularly individualized (precision medicine) treatment in adipose tissue (targeted therapy) and in organs of insulin resistance.
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Affiliation(s)
- Andreas Schäffler
- Klinik und Poliklinik für Innere Medizin III (Endokrinologie, Diabetologie, Stoffwechsel und Ernährungsmedizin), Justus-Liebig-Universität Gießen (JLU) und Universitätsklinikum Gießen und Marburg (UKGM), Standort Gießen, Klinikstraße 33, 35392, Gießen, Deutschland.
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Al Madhoun A, Kochumon S, Haddad D, Thomas R, Nizam R, Miranda L, Sindhu S, Bitar MS, Ahmad R, Al-Mulla F. Adipose Tissue Caveolin-1 Upregulation in Obesity Involves TNF-α/NF-κB Mediated Signaling. Cells 2023; 12:cells12071019. [PMID: 37048092 PMCID: PMC10093236 DOI: 10.3390/cells12071019] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 03/19/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Obesity is characterized by chronic low-grade inflammation. Obese people have higher levels of caveolin-1 (CAV1), a structural and functional protein present in adipose tissues (ATs). We aimed to define the inflammatory mediators that influence CAV1 gene regulation and the associated mechanisms in obesity. Using subcutaneous AT from 27 (7 lean and 20 obese) normoglycemic individuals, in vitro human adipocyte models, and in vivo mice models, we found elevated CAV1 expression in obese AT and a positive correlation between the gene expression of CAV1, tumor necrosis factor-alpha (TNF-α), and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). CAV1 gene expression was associated with proinflammatory cytokines and chemokines and their cognate receptors (r ≥ 0.447, p ≤ 0.030), but not with anti-inflammatory markers. CAV1 expression was correlated with CD163, indicating a prospective role for CAV1 in the adipose inflammatory microenvironment. Unlike wild-type animals, mice lacking TNF-α exhibited reduced levels of CAV1 mRNA/proteins, which were elevated by administering exogenous TNF-α. Mechanistically, TNF-α induces CAV1 gene transcription by mediating NF-κB binding to its two regulatory elements located in the CAV1 proximal regulatory region. The interplay between CAV1 and the TNF-α signaling pathway is intriguing and has potential as a target for therapeutic interventions in obesity and metabolic syndromes.
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Affiliation(s)
- Ashraf Al Madhoun
- Genetics and Bioinformatics, Dasman Diabetes Institute, Dasman 15462, Kuwait; (D.H.); (R.N.); (M.S.B.)
- Animal and Imaging Core Facilities, Dasman Diabetes Institute, Dasman 15462, Kuwait; (L.M.); (S.S.)
- Correspondence: (A.A.M.); (R.A.); (F.A.-M.); Tel.: +965-2224-2999 (ext. 2211) (F.A.-M.)
| | - Shihab Kochumon
- Immunology & Microbiology Department, Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (R.T.)
| | - Dania Haddad
- Genetics and Bioinformatics, Dasman Diabetes Institute, Dasman 15462, Kuwait; (D.H.); (R.N.); (M.S.B.)
| | - Reeby Thomas
- Immunology & Microbiology Department, Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (R.T.)
| | - Rasheeba Nizam
- Genetics and Bioinformatics, Dasman Diabetes Institute, Dasman 15462, Kuwait; (D.H.); (R.N.); (M.S.B.)
| | - Lavina Miranda
- Animal and Imaging Core Facilities, Dasman Diabetes Institute, Dasman 15462, Kuwait; (L.M.); (S.S.)
| | - Sardar Sindhu
- Animal and Imaging Core Facilities, Dasman Diabetes Institute, Dasman 15462, Kuwait; (L.M.); (S.S.)
- Immunology & Microbiology Department, Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (R.T.)
| | - Milad S. Bitar
- Genetics and Bioinformatics, Dasman Diabetes Institute, Dasman 15462, Kuwait; (D.H.); (R.N.); (M.S.B.)
- Department of Pharmacology, Faculty of Medicine, Kuwait University, Jabriya 046300, Kuwait
| | - Rasheed Ahmad
- Immunology & Microbiology Department, Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (R.T.)
- Correspondence: (A.A.M.); (R.A.); (F.A.-M.); Tel.: +965-2224-2999 (ext. 2211) (F.A.-M.)
| | - Fahd Al-Mulla
- Genetics and Bioinformatics, Dasman Diabetes Institute, Dasman 15462, Kuwait; (D.H.); (R.N.); (M.S.B.)
- Correspondence: (A.A.M.); (R.A.); (F.A.-M.); Tel.: +965-2224-2999 (ext. 2211) (F.A.-M.)
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9
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Choi YH, Kim BS, Kang SS. Inhibitory Effect of Genomic DNA Extracted from Pediococcus acidilactici on Porphyromonas gingivalis Lipopolysaccharide-Induced Inflammatory Responses. Food Sci Anim Resour 2023; 43:101-112. [PMID: 36789204 PMCID: PMC9890371 DOI: 10.5851/kosfa.2022.e62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 10/01/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022] Open
Abstract
This study aimed to assess whether genomic DNA (gDNA) extracted from Pediococcus acidilactici inhibits Porphyromonas gingivalis lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 cells. Pretreatment with gDNA of P. acidilactici K10 or P. acidilactici HW01 for 15 h effectively inhibited P. gingivalis LPS-induced mRNA expression of interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein (MCP)-1. Although both gDNAs did not dose-dependently inhibit P. gingivalis LPS-induced mRNA expression of IL-6 and MCP-1, they inhibited IL-1β mRNA expression in a dose-dependent manner. Moreover, pretreatment with both gDNAs inhibited the secretion of IL-1β, IL-6, and MCP-1. When RAW 264.7 cells were stimulated with P. gingivalis LPS alone, the phosphorylation of mitogen-activated protein kinases (MAPKs) was increased. However, the phosphorylation of MAPKs was reduced in the presence of gDNAs. Furthermore, both gDNAs restored IκBα degradation induced by P. gingivalis LPS, indicating that both gDNAs suppressed the activation of nuclear factor-κB (NF-κB). In summary, P. acidilactici gDNA could inhibit P. gingivalis LPS-induced inflammatory responses through the suppression of MAPKs and NF-κB, suggesting that P. acidilactici gDNA could be effective in preventing periodontitis.
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Affiliation(s)
- Young Hyeon Choi
- Department of Food Science and
Biotechnology, College of Life Science and Biotechnology, Dongguk
University, Goyang 10326, Korea
| | - Bong Sun Kim
- Department of Food Science and
Biotechnology, College of Life Science and Biotechnology, Dongguk
University, Goyang 10326, Korea
| | - Seok-Seong Kang
- Department of Food Science and
Biotechnology, College of Life Science and Biotechnology, Dongguk
University, Goyang 10326, Korea
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10
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Kolesnikova IM, Gaponov AM, Roumiantsev SA, Karbyshev MS, Grigoryeva TV, Makarov VV, Yudin SM, Borisenko OV, Shestopalov AV. Relationship between Blood Microbiome and Neurotrophin Levels in Different Metabolic Types of Obesity. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022060229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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11
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Saber MM, Monir N, Awad AS, Elsherbiny ME, Zaki HF. TLR9: A friend or a foe. Life Sci 2022; 307:120874. [PMID: 35963302 DOI: 10.1016/j.lfs.2022.120874] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/05/2022] [Accepted: 08/06/2022] [Indexed: 10/15/2022]
Abstract
The innate immune system is a primary protective line in our body. It confers its protection through different pattern recognition receptors (PRRs), especially toll like receptors (TLRs). Toll like receptor 9 (TLR9) is an intracellular TLR, expressed in different immunological and non-immunological cells. Release of cellular components, such as proteins, nucleotides, and DNA confers a beneficial inflammatory response and maintains homeostasis for removing cellular debris during normal physiological conditions. However, during pathological cellular damage and stress signals, engagement between mtDNA and TLR9 acts as an alarm for starting inflammatory and autoimmune disorders. The controversial role of TLR9 in different diseases baffled scientists if it has a protective or deleterious effect after activation during insults. Targeting the immune system, especially the TLR9 needs further investigation to provide a therapeutic strategy to control inflammation and autoimmune disorders.
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Affiliation(s)
- Mona M Saber
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Giza, Egypt.
| | - Nada Monir
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ahram Canadian University, Giza, Egypt
| | - Azza S Awad
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ahram Canadian University, Giza, Egypt
| | - Marwa E Elsherbiny
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ahram Canadian University, Giza, Egypt
| | - Hala F Zaki
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Giza, Egypt
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12
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Clerbaux LA, Albertini MC, Amigó N, Beronius A, Bezemer GFG, Coecke S, Daskalopoulos EP, del Giudice G, Greco D, Grenga L, Mantovani A, Muñoz A, Omeragic E, Parissis N, Petrillo M, Saarimäki LA, Soares H, Sullivan K, Landesmann B. Factors Modulating COVID-19: A Mechanistic Understanding Based on the Adverse Outcome Pathway Framework. J Clin Med 2022; 11:4464. [PMID: 35956081 PMCID: PMC9369763 DOI: 10.3390/jcm11154464] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 12/10/2022] Open
Abstract
Addressing factors modulating COVID-19 is crucial since abundant clinical evidence shows that outcomes are markedly heterogeneous between patients. This requires identifying the factors and understanding how they mechanistically influence COVID-19. Here, we describe how eleven selected factors (age, sex, genetic factors, lipid disorders, heart failure, gut dysbiosis, diet, vitamin D deficiency, air pollution and exposure to chemicals) influence COVID-19 by applying the Adverse Outcome Pathway (AOP), which is well-established in regulatory toxicology. This framework aims to model the sequence of events leading to an adverse health outcome. Several linear AOPs depicting pathways from the binding of the virus to ACE2 up to clinical outcomes observed in COVID-19 have been developed and integrated into a network offering a unique overview of the mechanisms underlying the disease. As SARS-CoV-2 infectibility and ACE2 activity are the major starting points and inflammatory response is central in the development of COVID-19, we evaluated how those eleven intrinsic and extrinsic factors modulate those processes impacting clinical outcomes. Applying this AOP-aligned approach enables the identification of current knowledge gaps orientating for further research and allows to propose biomarkers to identify of high-risk patients. This approach also facilitates expertise synergy from different disciplines to address public health issues.
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Affiliation(s)
- Laure-Alix Clerbaux
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
| | | | - Núria Amigó
- Biosfer Teslab SL., 43204 Reus, Spain;
- Department of Basic Medical Sciences, Universitat Rovira i Virgili (URV), 23204 Reus, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
| | - Anna Beronius
- Institute of Environmental Medicine, Karolinska Institutet, 17177 Stockholm, Sweden;
| | - Gillina F. G. Bezemer
- Impact Station, 1223 JR Hilversum, The Netherlands;
- Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands
| | - Sandra Coecke
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
| | - Evangelos P. Daskalopoulos
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
| | - Giusy del Giudice
- Finnish Hub for Development and Validation of Integrated Approaches (FHAIVE), Faculty of Medicine and Health Technology, Tampere University, 33100 Tampere, Finland; (G.d.G.); (D.G.); (L.A.S.)
| | - Dario Greco
- Finnish Hub for Development and Validation of Integrated Approaches (FHAIVE), Faculty of Medicine and Health Technology, Tampere University, 33100 Tampere, Finland; (G.d.G.); (D.G.); (L.A.S.)
| | - Lucia Grenga
- Département Médicaments et Technologies pour la Santé (DMTS), Université Paris-Saclay, CEA, INRAE, SPI, F-30200 Bagnols-sur-Ceze, France;
| | - Alberto Mantovani
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, 00161 Rome, Italy;
| | - Amalia Muñoz
- European Commission, Joint Research Centre (JRC), 2440 Geel, Belgium;
| | - Elma Omeragic
- Faculty of Pharmacy, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina;
| | - Nikolaos Parissis
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
| | - Mauro Petrillo
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
| | - Laura A. Saarimäki
- Finnish Hub for Development and Validation of Integrated Approaches (FHAIVE), Faculty of Medicine and Health Technology, Tampere University, 33100 Tampere, Finland; (G.d.G.); (D.G.); (L.A.S.)
| | - Helena Soares
- Laboratory of Immunobiology and Pathogenesis, Chronic Diseases Research Centre, Faculdade de Ciências Médicas Medical School, University of Lisbon, 1649-004 Lisbon, Portugal;
| | - Kristie Sullivan
- Physicians Committee for Responsible Medicine, Washington, DC 20016, USA;
| | - Brigitte Landesmann
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
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13
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Thomalla M, Schmid A, Hehner J, Koehler S, Neumann E, Müller-Ladner U, Schäffler A, Karrasch T. Toll-like Receptor 7 (TLR7) Is Expressed in Adipocytes and the Pharmacological TLR7 Agonist Imiquimod and Adipocyte-Derived Cell-Free Nucleic Acids (cfDNA) Regulate Adipocyte Function. Int J Mol Sci 2022; 23:ijms23158475. [PMID: 35955609 PMCID: PMC9369246 DOI: 10.3390/ijms23158475] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 02/05/2023] Open
Abstract
Endosome-localized Toll-like receptors (TLRs) 3 and 9 are expressed and functionally active in adipocytes. The functionality and role of TLR7 in adipocyte biology and innate immunity of adipose tissue (AT) is poorly characterized. We analyzed TLR7 mRNA and protein expression in murine 3T3-L1 and primary adipocytes, in co-cultures of 3T3-L1 adipocytes with murine J774A.1 monocytes and in human AT. The effects of TLR7 agonists imiquimod (IMQ) and cell-free nucleic acids (cfDNA) on adipokine concentration in cell-culture supernatants and gene expression profile were investigated. We found that TLR7 expression is strongly induced during adipocyte differentiation. TLR7 gene expression in adipocytes and AT stroma-vascular cells (SVC) seems to be independent of TLR9. IMQ downregulates resistin concentration in adipocyte cell-culture supernatants and modulates gene expression of glucose transporter Glut4. Adipocyte-derived cfDNA reduces adiponectin and resistin in cell-culture supernatants and potentially inhibits Glut4 gene expression. The responsiveness of 3T3-L1 adipocytes to imiquimod is preserved in co-culture with J774A.1 monocytes. Obesity-related, adipocyte-derived cfDNA engages adipocytic pattern recognition receptors (PRRs), modulating AT immune and metabolic homeostasis during adipose inflammation.
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Affiliation(s)
- Miriam Thomalla
- Department of Internal Medicine III, Justus-Liebig-University Giessen, 35390 Gießen, Germany; (M.T.); (A.S.); (J.H.); (S.K.); (A.S.)
| | - Andreas Schmid
- Department of Internal Medicine III, Justus-Liebig-University Giessen, 35390 Gießen, Germany; (M.T.); (A.S.); (J.H.); (S.K.); (A.S.)
| | - Julia Hehner
- Department of Internal Medicine III, Justus-Liebig-University Giessen, 35390 Gießen, Germany; (M.T.); (A.S.); (J.H.); (S.K.); (A.S.)
| | - Sebastian Koehler
- Department of Internal Medicine III, Justus-Liebig-University Giessen, 35390 Gießen, Germany; (M.T.); (A.S.); (J.H.); (S.K.); (A.S.)
| | - Elena Neumann
- Department of Rheumatology and Clinical Immunology, Justus-Liebig-University Giessen, Campus Kerckhoff, 61231 Bad Nauheim, Germany; (E.N.); (U.M.-L.)
| | - Ulf Müller-Ladner
- Department of Rheumatology and Clinical Immunology, Justus-Liebig-University Giessen, Campus Kerckhoff, 61231 Bad Nauheim, Germany; (E.N.); (U.M.-L.)
| | - Andreas Schäffler
- Department of Internal Medicine III, Justus-Liebig-University Giessen, 35390 Gießen, Germany; (M.T.); (A.S.); (J.H.); (S.K.); (A.S.)
| | - Thomas Karrasch
- Department of Internal Medicine III, Justus-Liebig-University Giessen, 35390 Gießen, Germany; (M.T.); (A.S.); (J.H.); (S.K.); (A.S.)
- Correspondence:
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14
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Liu X, Mai J, Meng C, Spiegel AJ, Wei W, Shen H. Antitumor Immunity from Abdominal Flap-Embedded Therapeutic Cancer Vaccine. Int J Nanomedicine 2022; 17:203-212. [PMID: 35046655 PMCID: PMC8760982 DOI: 10.2147/ijn.s341394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 12/26/2021] [Indexed: 11/23/2022] Open
Affiliation(s)
- Xiaoling Liu
- Department of Nanomedicine, Houston Methodist Academic Institute, Houston, TX, 77030, USA
- Department of Breast and Thyroid Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, 518036, People’s Republic of China
| | - Junhua Mai
- Department of Nanomedicine, Houston Methodist Academic Institute, Houston, TX, 77030, USA
| | - Chaoyang Meng
- Department of Nanomedicine, Houston Methodist Academic Institute, Houston, TX, 77030, USA
| | - Aldona J Spiegel
- Institute for Reconstructive Surgery, Houston Methodist Hospital, Weill Cornell Medicine, Houston, TX, USA
| | - Wei Wei
- Department of Breast and Thyroid Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, 518036, People’s Republic of China
| | - Haifa Shen
- Department of Nanomedicine, Houston Methodist Academic Institute, Houston, TX, 77030, USA
- Correspondence: Haifa Shen Department of Nanomedicine, Houston Methodist Academic Institute, Houston, TX, 77030, USATel +1 713-441-7321 Email
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15
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Gonzalez I, Araya P, Schneider I, Lindner C, Rojas A. Pattern recognition receptors and their roles in the host response to Helicobacter pylori infection. Future Microbiol 2021; 16:1229-1238. [PMID: 34615380 DOI: 10.2217/fmb-2021-0106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori (H. pylori) infection is highly prevalent, affecting 4.4 billion people globally. This pathogen is a risk factor in the pathogenesis of more than 75% of worldwide cases of gastric cancer. Pattern recognition receptors are essential in the innate immune response to H. pylori infection. They recognize conserved pathogen structures and myriad alarmins released by host cells in response to microbial components, cytokines or cellular stress, thus triggering a robust proinflammatory response, which is crucial in H. pylori-induced gastric carcinogenesis. In this review, we intend to highlight the main pattern recognition receptors involved in the recognition and host response to H. pylori, as well as the main structures recognized and the subsequent inflammatory response.
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Affiliation(s)
- Ileana Gonzalez
- Biomedical Research Labs, Medicine Faculty, Catholic University of Maule, Talca, 3460000, Chile
| | - Paulina Araya
- Biomedical Research Labs, Medicine Faculty, Catholic University of Maule, Talca, 3460000, Chile
| | - Ivan Schneider
- Biomedical Research Labs, Medicine Faculty, Catholic University of Maule, Talca, 3460000, Chile
| | - Cristian Lindner
- Biomedical Research Labs, Medicine Faculty, Catholic University of Maule, Talca, 3460000, Chile
| | - Armando Rojas
- Biomedical Research Labs, Medicine Faculty, Catholic University of Maule, Talca, 3460000, Chile
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16
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Karrasch T, Höpfinger A, Schäffler A, Schmid A. The adipokine C1q/TNF-related protein-3 (CTRP-3) inhibits Toll-like receptor (TLR)-induced expression of Cathelicidin antimicrobial peptide (CAMP) in adipocytes. Cytokine 2021; 148:155663. [PMID: 34388476 DOI: 10.1016/j.cyto.2021.155663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 01/22/2023]
Abstract
BACKGROUND AND AIM CAMP (Cathelicidin antimicrobial peptide) expression in adipocytes is regulated by Toll-like receptor (TLR) agonists. Secreted adipokines such as CTRP-3 have been suggested to participate in innate immune signaling in adipose tissue (AT). This study investigates whether TLR-induced CAMP expression in adipocytes is antagonized by CTRP-3. METHODS 3T3-L1 adipocytes were co-stimulated with TLR agonists (LPS, MALP-2, Pam3CSK4, pI:C) and recombinant CTRP-3. In a SIRS model, C57BL/6 wild-type mice were intraperitoneally (ip) injected with recombinant CTRP-3 prior to LPS. CAMP expression was analyzed by real-time PCR in AT of wild-type mice and in AT and primary adipocytes from transgenic mice lacking adipocyte CTRP-3 expression. Comparative transcriptome analysis by RNA seq. was applied in CTRP-3 KO adipocytes. RESULTS In vitro, CTRP-3 antagonized TLR4- and TLR1/2-induced CAMP expression in adipocytes whereas TLR3- and TLR2/6-mediated induction of CAMP was not affected. in vivo, application of exogenous CTRP-3 dose-dependently antagonized LPS-induced CAMP expression in intra-abdominal AT. CAMP expression in total AT and in primary adipocytes of subcutaneous and intra-abdominal AT did not differ between wild-type mice and transgenic mice lacking adipocyte CTRP-3 expression. CONCLUSIONS The study suggests a hypothetical role of CAMP in host defense not only against Gram-positive bacteria sensed by TLR1/2 and TLR2/6 but also against Gram-negative bacteria sensed by TLR4 and potentially against viruses sensed by TLR3. The machinery of TLR-mediated pro-inflammatory activation of the CAMP gene in adipocytes seems to be partly modulated by secreted adipokines belonging to the growing family of C1q/TNF-related proteins such as CTRP-3.
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Affiliation(s)
- Thomas Karrasch
- Department of Internal Medicine III, University of Giessen, Germany
| | | | | | - Andreas Schmid
- Department of Internal Medicine III, University of Giessen, Germany.
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17
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Mortaz E, Bezemer G, Alipoor SD, Varahram M, Mumby S, Folkerts G, Garssen J, Adcock IM. Nutritional Impact and Its Potential Consequences on COVID-19 Severity. Front Nutr 2021; 8:698617. [PMID: 34291074 PMCID: PMC8287001 DOI: 10.3389/fnut.2021.698617] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 05/24/2021] [Indexed: 12/24/2022] Open
Abstract
Background: During late 2019 a viral disease due to a novel coronavirus was reported in Wuhan, China, which rapidly developed into an exploding pandemic and poses a severe threat to human health all over the world. Until now (May 2021), there are insufficient treatment options for the management of this global disease and shortage of vaccines. Important aspects that help to defeat coronavirus infection seems to be having a healthy, strong, and resilient immune system. Nutrition and metabolic disorders, such as obesity and diabetes play a crucial role on the community health situation in general and especially during this new pandemic. There seems to be an enormous impact of lifestyle, metabolic disorders, and immune status on coronavirus disease 2019 (COVID-19) severity and recovery. For this reason, it is important to consider the impact of lifestyle and the consumption of well-defined healthy diets during the pandemic. Aims: In this review, we summarise recent findings on the effect of nutrition on COVID-19 susceptibility and disease severity and treatment. Understanding how specific dietary features might help to improve the public health strategies to reduce the rate and severity of COVID-19.
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Affiliation(s)
- Esmaeil Mortaz
- Department of Immunology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Clinical Tuberculosis and Epidemiology Research Centre, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Gillina Bezemer
- Division of Pharmacology, Faculty of Science, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, Netherlands
- Impact Station, Hilversum, Netherlands
| | - Shamila D. Alipoor
- Molecular Medicine Department, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Mohammad Varahram
- Mycobacteriology Research Centre, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sharon Mumby
- Airways Disease Section, Faculty of Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Gert Folkerts
- Division of Pharmacology, Faculty of Science, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, Netherlands
| | - Johan Garssen
- Division of Pharmacology, Faculty of Science, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, Netherlands
- Center of Excellence Immunology, Nutricia Research, Utrecht, Netherlands
| | - Ian M. Adcock
- Airways Disease Section, Faculty of Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
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18
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Schmid A, Schäffler A, Karrasch T. CTRP-3 Regulates NOD1-mediated Inflammation and NOD1 Expression in Adipocytes and Adipose Tissue. Inflammation 2021; 44:2260-2269. [PMID: 34165676 PMCID: PMC8616866 DOI: 10.1007/s10753-021-01497-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 05/28/2021] [Accepted: 06/02/2021] [Indexed: 11/29/2022]
Abstract
The anti-inflammatory adipokine CTRP-3 might affect innate immune reactions such as NOD1. The impact of CTRP-3 on NOD1-mediated inflammation in adipocytes and monocytic cells as well as on NOD1 expression was investigated. Murine 3T3-L1 pre-adipocytes and adipocytes as well as human THP-1 monocyte-like cells were co-stimulated with the synthetic NOD1 agonist Tri-DAP and recombinant CTRP-3. Gonadal adipose tissue and primary adipocytes were obtained from a murine model carrying a knockout (KO) of CTRP-3 in adipocytes but not in stroma-vascular cells. Wildtype mice with lipopolysaccharide (LPS)-induced elevated NOD1 expression were treated with CTRP-3. Secreted inflammatory cytokines in cell supernatants were measured by ELISA and mRNA levels were quantified by RT-PCR. Pro-inflammatory chemokine and cytokine secretion (MCP-1, RANTES, TNFα) was induced by NOD1 activation in adipocytes and monocyte-like cells, and MCP-1 and RANTES release was effectively inhibited by pre-incubation of cells with CTRP-3. CTRP-3 also antagonized LPS-triggered induction of NOD1 gene expression in murine adipose tissue, whereas adipocyte CTRP-3 deficiency upregulated NOD1 expression in adipose tissue. CTRP-3 is an effective antagonist of peptidoglycan-induced, NOD1-mediated inflammation and of LPS-induced NOD1 expression. Since basal NOD1 expression is increased by adipocyte CTRP-3 deficiency, there have to be also inflammation-independent mechanisms of NOD1 expression regulation by CTRP-3.
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Affiliation(s)
- Andreas Schmid
- Department of Internal Medicine III, University Hospital of Giessen, Giessen, Germany.
| | - Andreas Schäffler
- Department of Internal Medicine III, University Hospital of Giessen, Giessen, Germany
| | - Thomas Karrasch
- Department of Internal Medicine III, University Hospital of Giessen, Giessen, Germany
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19
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Bezemer GFG, Garssen J. TLR9 and COVID-19: A Multidisciplinary Theory of a Multifaceted Therapeutic Target. Front Pharmacol 2021; 11:601685. [PMID: 33519463 PMCID: PMC7844586 DOI: 10.3389/fphar.2020.601685] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/28/2020] [Indexed: 02/06/2023] Open
Abstract
By mapping the clinical pathophysiology of the novel coronavirus disease 2019 (COVID-19) against insights from virology, immunology, genomics, epidemiology and pharmacology, it is here proposed that the pathogen recognition receptor called toll like receptor 9 (TLR9) might have a pivotal role in the pathogenesis of COVID-19. Severe Acute Respiratory Syndrome Coronavirus 2, is causing the greatest global social and economic disruption since world war II. Lack of a vaccine, lack of successful treatment and limitations of the healthcare workforce and resources needed to safeguard patients with severe COVID-19 on the edge of life, demands radical preventive measures. It is urgently needed to identify biomarkers and drug candidates so that vulnerable individuals can be recognized early and severe multi-organ complications can be prevented or dampened. The TLR9 COVID-19 hypothesis describes a mechanism of action that could explain a wide spectrum of manifestations observed in patients with severe COVID-19. The introduced hypothesis proposes biomarkers for identification of vulnerable individuals and positions TLR9 as a promising multifaceted intervention target for prevention and/or treatment of COVID-19. TLR9 agonists might have value as prophylactic vaccine adjuvants and therapeutic immune stimulators at the early onset of disease. Additionally, in this current manuscript it is proposed for the first time that TLR9 could be considered as a target of "inhibition" aimed to dampen hyperinflammation and thrombotic complications in vulnerable patients that are at risk of developing late stages of COVID-19. The readily availability of TLR9 modulating drug candidates that have reached clinical testing for other disorders could favor a fast track development scenario, an important advantage under the current high unmet medical need circumstances regarding COVID-19.
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Affiliation(s)
- Gillina F. G. Bezemer
- Utrecht Institute of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, Netherlands
- Impact Station, Hilversum, Netherlands
| | - Johan Garssen
- Utrecht Institute of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, Netherlands
- Department of Immunology, Nutricia Research BV, Utrecht, Netherlands
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20
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Kawai T, Autieri MV, Scalia R. Adipose tissue inflammation and metabolic dysfunction in obesity. Am J Physiol Cell Physiol 2020; 320:C375-C391. [PMID: 33356944 DOI: 10.1152/ajpcell.00379.2020] [Citation(s) in RCA: 582] [Impact Index Per Article: 145.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Several lines of preclinical and clinical research have confirmed that chronic low-grade inflammation of adipose tissue is mechanistically linked to metabolic disease and organ tissue complications in the overweight and obese organism. Despite this widely confirmed paradigm, numerous open questions and knowledge gaps remain to be investigated. This is mainly due to the intricately intertwined cross-talk of various pro- and anti-inflammatory signaling cascades involved in the immune response of expanding adipose depots, particularly the visceral adipose tissue. Adipose tissue inflammation is initiated and sustained over time by dysfunctional adipocytes that secrete inflammatory adipokines and by infiltration of bone marrow-derived immune cells that signal via production of cytokines and chemokines. Despite its low-grade nature, adipose tissue inflammation negatively impacts remote organ function, a phenomenon that is considered causative of the complications of obesity. The aim of this review is to broadly present an overview of adipose tissue inflammation by highlighting the most recent reports in the scientific literature and summarizing our overall understanding of the field. We also discuss key endogenous anti-inflammatory mediators and analyze their mechanistic role(s) in the pathogenesis and treatment of adipose tissue inflammation. In doing so, we hope to stimulate studies to uncover novel physiological, cellular, and molecular targets for the treatment of obesity.
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Affiliation(s)
- Tatsuo Kawai
- The Cardiovascular Research Center and The Limole Center for Integrated Lymphatic Research, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Michael V Autieri
- The Cardiovascular Research Center and The Limole Center for Integrated Lymphatic Research, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Rosario Scalia
- The Cardiovascular Research Center and The Limole Center for Integrated Lymphatic Research, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
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21
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Zheng W, Xu Q, Zhang Y, E X, Gao W, Zhang M, Zhai W, Rajkumar RS, Liu Z. Toll-like receptor-mediated innate immunity against herpesviridae infection: a current perspective on viral infection signaling pathways. Virol J 2020; 17:192. [PMID: 33298111 PMCID: PMC7726878 DOI: 10.1186/s12985-020-01463-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 12/01/2020] [Indexed: 12/12/2022] Open
Abstract
Background In the past decades, researchers have demonstrated the critical role of Toll-like receptors (TLRs) in the innate immune system. They recognize viral components and trigger immune signal cascades to subsequently promote the activation of the immune system. Main body Herpesviridae family members trigger TLRs to elicit cytokines in the process of infection to activate antiviral innate immune responses in host cells. This review aims to clarify the role of TLRs in the innate immunity defense against herpesviridae, and systematically describes the processes of TLR actions and herpesviridae recognition as well as the signal transduction pathways involved. Conclusions Future studies of the interactions between TLRs and herpesviridae infections, especially the subsequent signaling pathways, will not only contribute to the planning of effective antiviral therapies but also provide new molecular targets for the development of antiviral drugs.
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Affiliation(s)
- Wenjin Zheng
- School of Basic Medical Sciences, Weifang Medical University, Weifang, 261053, China
| | - Qing Xu
- School of Anesthesiology, Weifang Medical University, Weifang, 261053, China
| | - Yiyuan Zhang
- School of Basic Medical Sciences, Weifang Medical University, Weifang, 261053, China
| | - Xiaofei E
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Wei Gao
- Key Lab for Immunology in Universities of Shandong Province, School of Basic Medical Sciences, Weifang Medical University, Weifang, 261053, China
| | - Mogen Zhang
- School of Basic Medical Sciences, Weifang Medical University, Weifang, 261053, China
| | - Weijie Zhai
- School of Basic Medical Sciences, Weifang Medical University, Weifang, 261053, China
| | | | - Zhijun Liu
- Department of Medical Microbiology, School of Basic Medical Sciences, Weifang Medical University, Weifang, 261053, China.
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22
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Claycombe-Larson KJ, Alvine T, Wu D, Kalupahana NS, Moustaid-Moussa N, Roemmich JN. Nutrients and Immunometabolism: Role of Macrophage NLRP3. J Nutr 2020; 150:1693-1704. [PMID: 32271912 DOI: 10.1093/jn/nxaa085] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/27/2020] [Accepted: 03/10/2020] [Indexed: 12/19/2022] Open
Abstract
Inflammation is largely mediated by immune cells responding to invading pathogens, whereas metabolism is oriented toward producing usable energy for vital cell functions. Immunometabolic alterations are considered key determinants of chronic inflammation, which leads to the development of chronic diseases. Studies have demonstrated that macrophages and the NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome are activated in key metabolic tissues to contribute to increased risk for type 2 diabetes mellitus, Alzheimer disease, and liver diseases. Thus, understanding the tissue-/cell-type-specific regulation of the NLRP3 inflammasome is crucial for developing intervention strategies. Currently, most of the nutrients and bioactive compounds tested to determine their inflammation-reducing effects are limited to animal models. Future studies need to address how dietary compounds regulate immune and metabolic cell reprograming in humans.
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Affiliation(s)
- Kate J Claycombe-Larson
- Grand Forks Human Nutrition Research Center, USDA Agricultural Research Service, Grand Forks, ND, USA
| | - Travis Alvine
- Grand Forks Human Nutrition Research Center, USDA Agricultural Research Service, Grand Forks, ND, USA
| | - Dayong Wu
- The Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA
| | | | - Naima Moustaid-Moussa
- Nutritional Science Department and Obesity Research Institute, Texas Tech University, Lubbock, TX, USA
| | - James N Roemmich
- Grand Forks Human Nutrition Research Center, USDA Agricultural Research Service, Grand Forks, ND, USA
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23
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Yang J, Fukuchi KI. TIR-Domain-Containing Adaptor-Inducing Interferon- β (TRIF) Is Involved in Glucose Metabolism in Adipose Tissue through the Insulin/AKT Signaling Pathway. Int J Endocrinol 2020; 2020:6942307. [PMID: 33376487 PMCID: PMC7744180 DOI: 10.1155/2020/6942307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 11/09/2020] [Accepted: 11/25/2020] [Indexed: 01/06/2023] Open
Abstract
Obesity significantly increases the risk of developing type 2 diabetes mellitus and other metabolic diseases. Obesity is associated with chronic low-grade inflammation in white adipose tissues, which is thought to play an essential role in developing insulin resistance. Many lines of evidence indicate that toll-like receptors (TLRs) and their downstream signaling pathways are involved in development of chronic low-grade inflammation and insulin resistance, which are associated with obesity. Mice lacking molecules positively involved in the TLR signaling pathways are generally protected from high-fat diet-induced inflammation and insulin resistance. In this study, we have determined the effects of genetic deficiency of toll/interleukin-1 receptor-domain-containing adaptor-inducing interferon-β (TRIF) on food intake, bodyweight, glucose metabolism, adipose tissue macrophage polarization, and insulin signaling in normal chow diet-fed mice to investigate the role of the TRIF-dependent TLR signaling in adipose tissue metabolism and inflammation. TRIF deficiency (TRIF-/-) increased food intake and bodyweight. The significant increase in bodyweight in TRIF-/- mice was discernible as early as 24 weeks of age and sustained thereafter. TRIF-/- mice showed impaired glucose tolerance in glucose tolerance tests, but their insulin tolerance tests were similar to those in TRIF+/+ mice. Although no difference was found in the epididymal adipose mass between the two groups, the percentage of CD206+ M2 macrophages in epididymal adipose tissue decreased in TRIF-/- mice compared with those in TRIF+/+ mice. Furthermore, activation of epididymal adipose AKT in response to insulin stimulation was remarkably diminished in TRIF-/- mice compared with TRIF+/+ mice. Our results indicate that the TRIF-dependent TLR signaling contributes to maintaining insulin/AKT signaling and M2 macrophages in epididymal adipose tissue under a normal chow diet and provide new evidence that TLR4-targeted therapies for type 2 diabetes require caution.
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Affiliation(s)
- Junling Yang
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine Peoria, 1 Illini Drive, Peoria, IL 61605, USA
| | - Ken-Ichiro Fukuchi
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine Peoria, 1 Illini Drive, Peoria, IL 61605, USA
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24
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Shepard CR. TLR9 in MAFLD and NASH: At the Intersection of Inflammation and Metabolism. Front Endocrinol (Lausanne) 2020; 11:613639. [PMID: 33584545 PMCID: PMC7880160 DOI: 10.3389/fendo.2020.613639] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022] Open
Abstract
Toll-Like Receptor 9 (TLR9) is an ancient receptor integral to the primordial functions of inflammation and metabolism. TLR9 functions to regulate homeostasis in a healthy system under acute stress. The literature supports that overactivation of TLR9 under the chronic stress of obesity is a critical driver of the pathogenesis of NASH and NASH-associated fibrosis. Research has focused on the core contributions of the parenchymal and non-parenchymal cells in the liver, adipose, and gut compartments. TLR9 is activated by endogenous circulating mitochondrial DNA (mtDNA). Chronically elevated circulating levels of mtDNA, caused by the stress of overnutrition, are observed in obesity, metabolic dysfunction-associated fatty liver disease (MAFLD), and NASH. Clinical evidence is supportive of TLR9 overactivation as a driver of disease. The role of TLR9 in metabolism and energy regulation may have an underappreciated contribution in the pathogenesis of NASH. Antagonism of TLR9 in NASH and NASH-associated fibrosis could be an effective therapeutic strategy to target both the inflammatory and metabolic components of such a complex disease.
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