1
|
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.
Collapse
Affiliation(s)
- Thomas Karrasch
- Department of Internal Medicine III, University of Giessen, Germany
| | | | | | - Andreas Schmid
- Department of Internal Medicine III, University of Giessen, Germany.
| |
Collapse
|
2
|
Zhang X, Nie Q, Zhang Z, Zhao J, Zhang F, Wang C, Wang X, Song G. Resveratrol affects the expression of uric acid transporter by improving inflammation. Mol Med Rep 2021; 24:564. [PMID: 34109437 PMCID: PMC8201466 DOI: 10.3892/mmr.2021.12203] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/27/2021] [Indexed: 12/15/2022] Open
Abstract
Resveratrol (RSV), a polyphenol, non‑flavonoid plant‑derived antitoxin, ameliorates hyperuricemia and kidney inflammation. The present study aimed to establish a model of high‑fat diet (HFD)‑induced insulin resistance (IR) and to determine the specific mechanism of RSV to improve kidney inflammation and reduce uric acid (UA). C57BL/6J mice were fed a HFD for 12 weeks and their glucose tolerance was evaluated by intraperitoneal glucose tolerance testing. The mice were then administered RSV for 6 weeks, and blood and kidney samples were collected. Serum UA and insulin concentrations were determined using ELISA kits. Hematoxylin and eosin, periodic acid‑Schiff and Masson staining were performed to observe the pathological changes of the kidney, and electron microscopy was used to observe changes in the kidney ultrastructure. The renal concentrations of interleukin (IL)‑6, IL‑18, IL‑1β and tumor necrosis factor‑α (TNF‑α) were measured using ELISA kits, and western blotting evaluated changes in the protein expression levels of various indicators. RSV significantly ameliorated HFD‑induced IR and reduced blood UA levels. Long‑term IR can lead to lipid deposition, glycogen accumulation, inflammatory damage and fibrotic changes in the kidney of mice. This leads to a significant increase in the expression of UA transport‑related proteins, an increase in UA reabsorption and an increase in blood UA levels. Notably, RSV intervention was able to reverse this process. The effect of RSV may be achieved by inhibiting the NOD‑like receptor family, pyrin domain‑containing 3 (NLRP3) inflammasome and Toll‑like receptor 4 (TLR4)/myeloid differentiation factor 88/nuclear factor‑κB signaling pathway. In conclusion, RSV may improve kidney inflammation through TLR4 and NLRP3 signaling pathways, and reduce the expression of UA transporter proteins in the kidney of insulin‑resistant mice, thereby reducing blood UA levels.
Collapse
Affiliation(s)
- Xuemei Zhang
- Department of Internal Medicine, Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
- Department of Rheumatism and Immunology, Hebei General Hospital, Shijiazhuang, Hebei 050000, P.R. China
| | - Qian Nie
- Department of Internal Medicine, Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
- Hebei Key Laboratory of Metabolic Diseases, Hebei General Hospital, Shijiazhuang, Hebei 050000, P.R. China
| | - Zhimei Zhang
- Department of Internal Medicine, Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
- Hebei Key Laboratory of Metabolic Diseases, Hebei General Hospital, Shijiazhuang, Hebei 050000, P.R. China
| | - Jing Zhao
- Department of Oncology, Hebei General Hospital, Shijiazhuang, Hebei 050000, P.R. China
| | - Fengxiao Zhang
- Department of Rheumatism and Immunology, Hebei General Hospital, Shijiazhuang, Hebei 050000, P.R. China
| | - Chao Wang
- Hebei Key Laboratory of Metabolic Diseases, Hebei General Hospital, Shijiazhuang, Hebei 050000, P.R. China
| | - Xing Wang
- Hebei Key Laboratory of Metabolic Diseases, Hebei General Hospital, Shijiazhuang, Hebei 050000, P.R. China
| | - Guangyao Song
- Department of Internal Medicine, Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
- Hebei Key Laboratory of Metabolic Diseases, Hebei General Hospital, Shijiazhuang, Hebei 050000, P.R. China
| |
Collapse
|
3
|
Evaluation of Fat Accumulation and Adipokine Production during the Long-Term Adipogenic Differentiation of Porcine Intramuscular Preadipocytes and Study of the Influence of Immunobiotics. Cells 2020; 9:cells9071715. [PMID: 32708964 PMCID: PMC7408200 DOI: 10.3390/cells9071715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 07/13/2020] [Accepted: 07/15/2020] [Indexed: 12/17/2022] Open
Abstract
The degree of fat accumulation and adipokine production are two major indicators of obesity that are correlated with increased adipose tissue mass and chronic inflammatory responses. Adipocytes have been considered effector cells for the inflammatory responses due to their capacity to express Toll-like receptors (TLRs). In this study, we evaluated the degree of fat accumulation and adipokine production in porcine intramuscular preadipocyte (PIP) cells maintained for in vitro differentiation over a long period without or with stimulation of either TNF-α or TLR2-, TLR3-, or TLR4-ligands. The cytosolic fat accumulation was measured by liquid chromatography and the expression of adipokines (CCL2, IL-6, IL-8 and IL-10) were quantified by RT-qPCR and ELISA at several time points (0 to 20 days) of PIP cells differentiation. Long-term adipogenic differentiation (LTAD) induced a progressive fat accumulation in the adipocytes over time. Activation of TLR3 and TLR4 resulted in an increased rate of fat accumulation into the adipocytes over the LTAD. The production of CCL2, IL-8 and IL-6 were significantly increased in unstimulated adipocytes during the LTAD, while IL-10 expression remained stable over the studied period. An increasing trend of adiponectin and leptin production was also observed during the LTAD. On the other hand, the stimulation of adipocytes with TLRs agonists or TNF-α resulted in an increasing trend of CCL2, IL-6 and IL-8 production while IL-10 remained stable in all four treatments during the LTAD. We also examined the influences of several immunoregulatory probiotic strains (immunobiotics) on the modulation of the fat accumulation and adipokine production using supernatants of immunobiotic-treated intestinal immune cells and the LTAD of PIP cells. Immunobiotics have shown a strain-specific ability to modulate the fat accumulation and adipokine production, and differentiation of adipocytes. Here, we expanded the utility and potential application of our in vitro PIP cells model by evaluating an LTAD period (20 days) in order to elucidate further insights of chronic inflammatory pathobiology of adipocytes associated with obesity as well as to explore the prospects of immunomodulatory intervention for obesity such as immunobiotics.
Collapse
|
4
|
Su H, Zhang C, Zou X, Lu F, Zeng Y, Guan H, Ren Y, Yuan F, Xu L, Zhang M, Dong H. Jiao-tai-wan inhibits inflammation of the gut-brain-axis and attenuates cognitive impairment in insomnic rats. JOURNAL OF ETHNOPHARMACOLOGY 2020; 250:112478. [PMID: 31843572 DOI: 10.1016/j.jep.2019.112478] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 12/10/2019] [Accepted: 12/10/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Jiao-tai-wan is a well-known traditional Chinese herbal medicine formula that is used to treat insomnia and systemic inflammation. Studies indicate chronic insomnia might contribute to the prevalence of cognitive impairment. The role of systemic inflammation and intestinal permeability in the progression of neurodegenerative diseases attracts much attention. AIM OF THE STUDY This study aimed to investigate if Jiao-tai-wan plays a role in promoting the repair of the intestinal epithelial barrier to suppress systemic inflammation and cognitive impairment in sleep-deprived (SD) rats. MATERIALS AND METHODS Male obesity-resistant SD rats were partially sleep-deprived for 16 weeks. During the last 8 weeks, they were treated with Jiao-tai-wan. A Morris water maze was used to analyze their cognitive ability. Aβ42 and proinflammation cytokines in the cerebrospinal fluid, tissue, or serum were determined using enzyme-linked immunosorbent assay or polymerase chain reaction. Intestinal permeability was detected using the fluorescein isothiocyanate-dextran perfusion assay method. Plasma lipopolysaccharide (LPS) levels were detected with Tachypleus Amebocyte Lysate. Western bolt was used in the signaling pathway analysis. RESULTS Sleep deprivation deteriorated the performance of rats in the Morris water maze and increased the Aβ42, caspase3, IL-6, and TNF-α levels in their brains. The intestinal TLR4/NF-κB pathway was activated with an increase in the expression of IL-6 and TNF-α. The expression of tight junction proteins was also decreased in the intestinal tissue. This increased the intestinal permeability and circulation of LPS, LPS binding protein, IL-6, and TNF-α. Treatment with Jiao-tai-wan could partly reverse these changes. CONCLUSION Jiao-tai-wan has the potential to attenuate systemic inflammation and cognitive impairment in partially sleep-deprived rats. The possible underlying mechanism is by preventing an inflammation trigger being transferred through the gut-brain-axis.
Collapse
Affiliation(s)
- Hao Su
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Chu Zhang
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Xin Zou
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Fuer Lu
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Yong Zeng
- Huanggang Traditional Chinese Medicine Hospital, Hubei University of Chinese Medicine, Huanggang, 438000, PR China
| | - Hongwei Guan
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Yanlin Ren
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Fen Yuan
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Lijun Xu
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Mingmin Zhang
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China
| | - Hui Dong
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China.
| |
Collapse
|
5
|
Dermal White Adipose Tissue: A Newly Recognized Layer of Skin Innate Defense. J Invest Dermatol 2019; 139:1002-1009. [DOI: 10.1016/j.jid.2018.12.031] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/27/2018] [Accepted: 12/03/2018] [Indexed: 12/14/2022]
|
6
|
Miura K, Ishioka M, Iijima K. The Roles of the Gut Microbiota and Toll-like Receptors in Obesity and Nonalcoholic Fatty Liver Disease. J Obes Metab Syndr 2017; 26:86-96. [PMID: 31089501 PMCID: PMC6484897 DOI: 10.7570/jomes.2017.26.2.86] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 02/28/2017] [Accepted: 03/16/2017] [Indexed: 02/06/2023] Open
Abstract
Obesity is characterized by low-grade chronic inflammation and is closely associated with the cardiovascular diseases, diabetes, and nonalcoholic fatty liver disease. Emerging data demonstrate that the gut microbiota contributes to the development of obesity by regulating the innate immune system, including the Toll-like receptors (TLRs): an altered gut microbiota composition and elevated TLR ligands are observed in obese mice and humans. The changes in the gut microbiota include an increased abundance of Firmicutes phylum and a decreased abundance of Bacteroidetes phylum. The population of beneficial bacteria that function as probiotics is decreased whereas harmful bacteria that can produce lipopolysaccharide, a TLR4 ligand, are increased in the obese state. In addition, the gut permeability is increased in obesity, which allows the delivery of larger amounts of bacterial components to the liver through the portal vein. Immune cells recognize these bacterial components through TLRs and produce diverse cytokines that kill invading pathogens. However, the sustained activation of TLR signaling induces host damage due to chronic exposure to harmful cytokines, which are produced from TLR expressing cells, including monocytes/macrophages. In the obese state, the expression of TLR is increased in several organs, including the adipose tissue and the liver. At the cell level, negative regulators of TLR signaling are suppressed, leading to activation of TLR signaling. These alterations promote inflammation in many organs. Thus, the gut microbiota and TLR signaling are therapeutic targets in patients with obesity and its related diseases.
Collapse
Affiliation(s)
- Kouichi Miura
- Department of Gastroenterology, Akita University Graduate School of Medicine, Akita, Japan
| | - Mitsuaki Ishioka
- Department of Gastroenterology, Akita University Graduate School of Medicine, Akita, Japan
| | - Katsunori Iijima
- Department of Gastroenterology, Akita University Graduate School of Medicine, Akita, Japan
| |
Collapse
|
7
|
Su MS, Xu L, Xu K, Zheng JS. Association of T lymphocyte immune imbalance and IL-10 gene polymorphism with the risk of obstructive sleep apnea in children with obesity. Sleep Breath 2017; 21:929-937. [PMID: 28500380 DOI: 10.1007/s11325-017-1504-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/16/2017] [Accepted: 04/12/2017] [Indexed: 12/30/2022]
Abstract
PURPOSE The purpose of this study is to determine the role of T lymphocyte immune imbalance and interleukin (IL)-10 gene polymorphism in the development of obstructive sleep apnea (OSA) in obese children. METHODS One hundred obese children at high-risk and low-risk for OSA based upon a sleep questionnaire were selected. Peripheral blood T lymphocyte subsets were measured by flow cytometry, and plasma IFN-γ, IL-4, and IL-10 cytokines were detected by ELISA. The relationships between OSA and the above variables were analyzed. IL-10 gene polymorphisms were analyzed by DNA sequencing. RESULTS Ninety subjects completed all the tests. Forty-two patients were diagnosed as OSA by PSG. Compared with non-OSA children, the levels of CD4+ T cells, IFN-γ, and IL-4 were increased (P < 0.05) whereas the numbers of CD4+ CD25+ Treg and NKT cells and the levels of IL-10 were reduced (P < 0.05). Multiple linear regression analysis showed that IL-10 level was negatively associated with OAHI (OR 0.352, 95% CI 0.286-0.540; P < 0.05). In multivariate analysis, IL-10 also had a strong negative association with OSA after adjustment for confounding factors from models 1 to 3. Correlative analysis showed that IL-10 levels had a positive association with CD4+ CD25+ Treg (r = 0.628, P < 0.01). Furthermore, the IL-10/A-1082G gene polymorphism correlated with OSA. CONCLUSIONS T lymphocyte immune imbalance was associated with OSA and IL-10 may play an important protective role in the pathogenesis of OSA in obese children.
Collapse
Affiliation(s)
- Miao-Shang Su
- Department of Pediatric Respiratory and Sleep Medicine, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang Province, People's Republic of China.
| | - Li Xu
- Department of Pediatric Respiratory and Sleep Medicine, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang Province, People's Republic of China
| | - Kang Xu
- Department of Pediatrics, The Qingtian People's Hospital, Zhejiang Province, People's Republic of China
| | - Ji-Shan Zheng
- Department of Pediatrics, The Ningbo Women and Children's Hospital, Zhejiang Province, People's Republic of China
| |
Collapse
|
8
|
Innate Immunity of Adipose Tissue in Rodent Models of Local and Systemic Staphylococcus aureus Infection. Mediators Inflamm 2017; 2017:5315602. [PMID: 28428684 PMCID: PMC5385907 DOI: 10.1155/2017/5315602] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/13/2017] [Indexed: 12/31/2022] Open
Abstract
Background. The role of adipose tissue in systemic inflammation during bacterial infection is unclear. Effects of Staphylococcus aureus infection on adipocytes in rodent models of experimental endocarditis and peritonitis, the impact of S. aureus infection on gene expression in epididymal and subcutaneous adipose tissue, and effects of S. aureus infection on the toll-like receptor-2- (TLR2-) cathelicidin pathway in vivo and in vitro were investigated. Material and methods. The rat model of catheter-induced S. aureus endocarditis and the mouse model of S. aureus-induced peritonitis were used for infection experiments, gene expression profiling in adipose tissue, and measurement of cytokines. 3T3-L1 adipocytes were analyzed for expression of the TLR2-cathelicidin pathway. Results. Upon systemic bacterial infection by S. aureus, there is a shift from anti- to proinflammatory cytokines in serum and in adipose tissue gene expression. The TLR2-cathelicidin pathway is increasingly expressed during adipocyte differentiation in vitro and is induced upon stimulation by synthetic lipopeptides. Conclusions. Systemic infection by Gram-positive bacteria induces proinflammatory transformation of adipose tissue sites distinct from infection sites, documented on the levels of gene expression and secreted mediators. The TLR2-cathelicidine pathway is expressed and highly inducible in adipocytes in vitro. Lipopeptides are important immune-modulators of adipocytes in both gene expression and protein secretion.
Collapse
|
9
|
Karrasch T, Schaeffler A. Adipokines and the role of visceral adipose tissue in inflammatory bowel disease. Ann Gastroenterol 2016; 29:424-438. [PMID: 27708507 PMCID: PMC5049548 DOI: 10.20524/aog.2016.0077] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 07/22/2016] [Indexed: 12/20/2022] Open
Abstract
Recently, adipocytes have been recognized as actively participating in local and systemic immune responses via the secretion of peptides detectable in relevant levels in the systemic circulation, the so-called "adipo(cyto)kines". Multiple studies appearing within the last 10-15 years have focused on the possible impact of adipose tissue depots on inflammatory bowel disease (IBD). Consequently, various hypotheses regarding the role of different adipokines in inflammatory diseases in general and in intestinal inflammatory processes in particular have been developed and have been further refined in recent years. After a focused summary of the data reported concerning the impact of visceral adipose tissue on IBD, such as Crohn's disease and ulcerative colitis, our review focuses on recent developments indicating that adipocytes as part of the innate immune system actively participate in antimicrobial host defenses in the context of intestinal bacterial translocation, which are of utmost importance for the homeostasis of the whole organism. Modulators of adipose tissue function and regulators of adipokine secretion, as well as modifiers of adipocytic pattern recognition molecules, might represent future potential drug targets in IBD.
Collapse
Affiliation(s)
- Thomas Karrasch
- Department of Internal Medicine III, Giessen University Hospital, Germany
| | - Andreas Schaeffler
- Department of Internal Medicine III, Giessen University Hospital, Germany
| |
Collapse
|
10
|
Sultana A, Cochran BJ, Tabet F, Patel M, Torres LC, Barter PJ, Rye KA. Inhibition of inflammatory signaling pathways in 3T3-L1 adipocytes by apolipoprotein A-I. FASEB J 2016; 30:2324-35. [PMID: 26965683 DOI: 10.1096/fj.201500026r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 02/22/2016] [Indexed: 01/04/2023]
Abstract
Activation of inflammatory signaling pathways links obesity with metabolic disorders. TLR4-mediated activation of MAPKs and NF-κB are 2 such pathways implicated in obesity-induced inflammation. Apolipoprotein A-I (apoA-I) exerts anti-inflammatory effects on adipocytes by effluxing cholesterol from the cells via the ATP binding cassette transporter A1 (ABCA1). It is not known if these effects involve inhibition of inflammatory signaling pathways by apoA-I. This study asks if apoA-I inhibits activation of MAPKs and NF-κB in mouse 3T3-L1 adipocytes and whether this inhibition is ABCA1 dependent. Incubation of differentiated 3T3-L1 adipocytes with apoA-I decreased cell surface expression of TLR4 by 16 ± 2% and synthesis of the TLR4 adaptor protein, myeloid differentiation primary response 88, by 24 ± 4% in an ABCA1-dependent manner. ApoA-I also inhibited downstream activation of MAPKs, such as ERK, p38MAPK, and JNK, as well as expression of proinflammatory adipokines in bacterial LPS-stimulated 3T3-L1 adipocytes in an ABCA1-dependent manner. ApoA-I, by contrast, suppressed nuclear localization of the p65 subunit of NF-κB by 30 ± 3% in LPS-stimulated 3T3-L1 adipocytes in an ABCA1-independent manner. In conclusion, apoA-I inhibits TLR4-mediated inflammatory signaling pathways in adipocytes by preventing MAPK and NF-κB activation.-Sultana, A., Cochran, B. J., Tabet, F., Patel, M., Cuesta Torres, L., Barter, P. J., Rye, K.-A. Inhibition of inflammatory signaling pathways in 3T3-L1 adipocytes by apolipoprotein A-I.
Collapse
Affiliation(s)
- Afroza Sultana
- Lipid Research Group, School of Medical Sciences, Faculty of Medicine, University of New South Wales Australia, Sydney, New South Wales, Australia; and
| | - Blake J Cochran
- Lipid Research Group, School of Medical Sciences, Faculty of Medicine, University of New South Wales Australia, Sydney, New South Wales, Australia; and
| | - Fatiha Tabet
- Lipid Research Group, School of Medical Sciences, Faculty of Medicine, University of New South Wales Australia, Sydney, New South Wales, Australia; and
| | - Mili Patel
- Lipid Research Group, School of Medical Sciences, Faculty of Medicine, University of New South Wales Australia, Sydney, New South Wales, Australia; and
| | - Luisa Cuesta Torres
- Lipid Research Group, School of Medical Sciences, Faculty of Medicine, University of New South Wales Australia, Sydney, New South Wales, Australia; and
| | - Philip J Barter
- Lipid Research Group, School of Medical Sciences, Faculty of Medicine, University of New South Wales Australia, Sydney, New South Wales, Australia; and Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia
| | - Kerry-Anne Rye
- Lipid Research Group, School of Medical Sciences, Faculty of Medicine, University of New South Wales Australia, Sydney, New South Wales, Australia; and Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
11
|
Abstract
The innate immune system includes several classes of pattern recognition receptors (PRRs), including membrane-bound Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs). These receptors detect pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) in the extracellular and intracellular space. Intracellular NLRs constitute inflammasomes, which activate and release caspase-1, IL-1β, and IL-18 thereby initiating an inflammatory response. Systemic and local low-grade inflammation and release of proinflammatory cytokines are implicated in the development and progression of diabetes mellitus and diabetic nephropathy. TLR2, TLR4, and the NLRP3 inflammasome can induce the production of various proinflammatory cytokines and are critically involved in inflammatory responses in pancreatic islets, and in adipose, liver and kidney tissues. This Review describes how innate immune system-driven inflammatory processes can lead to apoptosis, tissue fibrosis, and organ dysfunction resulting in insulin resistance, impaired insulin secretion, and renal failure. We propose that careful targeting of TLR2, TLR4, and NLRP3 signalling pathways could be beneficial for the treatment of diabetes mellitus and diabetic nephropathy.
Collapse
|
12
|
Involvement of Visceral Adipose Tissue in Immunological Modulation of Inflammatory Cascade in Preeclampsia. Mediators Inflamm 2015; 2015:325932. [PMID: 26089598 PMCID: PMC4458290 DOI: 10.1155/2015/325932] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/04/2015] [Indexed: 01/12/2023] Open
Abstract
Objectives. The pathophysiology of preeclampsia is characterized by abnormal placentation, an exaggerated inflammatory response, and generalized dysfunction of the maternal endothelium. We investigated the effects of preeclampsia serum on the expression of inflammation-related genes by adipose tissue. Materials and Methods. Visceral adipose tissue was obtained from the omentum of patients with early ovarian cancer without metastasis. Adipose tissue was incubated with sera obtained from either five women affected with severe preeclampsia or five women from control pregnant women at 37°C in a humidified incubator at 5% CO2 for 24 hours. 370 genes in total mRNA were analyzed with quantitative RT-PCR (Inflammatory Response & Autoimmunity gene set). Results. Gene expression analysis revealed changes in the expression levels of 30 genes in adipose tissue treated with preeclampsia sera. Some genes are related to immune response, oxidative stress, insulin resistance, and adipogenesis, which plays a central role in excessive systemic inflammatory response of preeclampsia. In contrast, other genes have shown beneficial effects in the regulation of Th2 predominance, antioxidative stress, and insulin sensitivity. Conclusion. In conclusion, visceral adipose tissue offers protection against inflammation, oxidative insults, and other forms of cellular stress that are central to the pathogenesis of preeclampsia.
Collapse
|
13
|
Ballak DB, van Asseldonk EJP, van Diepen JA, Jansen H, Hijmans A, Joosten LAB, Tack CJ, Netea MG, Stienstra R. TLR-3 is present in human adipocytes, but its signalling is not required for obesity-induced inflammation in adipose tissue in vivo. PLoS One 2015; 10:e0123152. [PMID: 25867514 PMCID: PMC4395029 DOI: 10.1371/journal.pone.0123152] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 02/21/2015] [Indexed: 12/16/2022] Open
Abstract
Innate immunity plays a pivotal role in obesity-induced low-grade inflammation originating from adipose tissue. Key receptors of the innate immune system including Toll-like receptors-2 and -4 (TLRs) are triggered by nutrient excess to promote inflammation. The role of other TLRs in this process is largely unknown. In addition to double-stranded viral mRNA, TLR-3 can also recognize mRNA from dying endogenous cells, a process that is frequently observed within obese adipose tissue. Here, we identified profound expression of TLR-3 in adipocytes and investigated its role during diet-induced obesity. Human adipose tissue biopsies (n=80) and an adipocyte cell-line were used to study TLR-3 expression and function. TLR-3-/- and WT animals were exposed to a high-fat diet (HFD) for 16 weeks to induce obesity. Expression of TLR-3 was significantly higher in human adipocytes compared to the non-adipocyte cells part of the adipose tissue. In vitro, TLR-3 expression was induced during differentiation of adipocytes and stimulation of the receptor led to elevated expression of pro-inflammatory cytokines. In vivo, TLR-3 deficiency did not significantly influence HFD-induced obesity, insulin sensitivity or inflammation. In humans, TLR-3 expression in adipose tissue did not correlate with BMI or insulin sensitivity (HOMA-IR). Together, our results demonstrate that TLR-3 is highly expressed in adipocytes and functionally active. However, TLR-3 appears to play a redundant role in obesity-induced inflammation and insulin resistance.
Collapse
Affiliation(s)
- Dov B. Ballak
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Janna A. van Diepen
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Henry Jansen
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anneke Hijmans
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Leo A. B. Joosten
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Cees J. Tack
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Mihai G. Netea
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rinke Stienstra
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Human Nutrition, Wageningen University and Research Centre, Wageningen, The Netherlands
| |
Collapse
|
14
|
Montazeri M, Sanchez-Lopez JA, Caballero I, Maslehat Lay N, Elliott S, López-Martín S, Yáñez-Mó M, Fazeli A. Activation of Toll-like receptor 3 reduces actin polymerization and adhesion molecule expression in endometrial cells, a potential mechanism for viral-induced implantation failure. Hum Reprod 2015; 30:893-905. [PMID: 25605704 DOI: 10.1093/humrep/deu359] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
STUDY QUESTION Does activation of endometrial Toll-like receptor 3 (TLR 3) affect cell receptivity to trophoblast adhesion? SUMMARY ANSWER TLR 3 activation in vitro reduces the attachment of trophoblast cells to endometrial cells by altering the cell cytoskeleton and reducing the expression of adhesion molecules in human endometrial cells. WHAT IS KNOWN ALREADY It is well documented that the presence of an infection at the time of implantation can lead to implantation failure. The female reproductive tract recognizes invading micro-organisms through the innate pathogen recognition receptors such as the TLRs. STUDY DESIGN, SIZE, DURATION Poly I:C was used as a TLR 3-specific ligand and endometrial cells were either treated or not with Poly I:C (treated versus control) in vitro. The experiments were performed in three replicates on three separate days. PARTICIPANTS/MATERIALS, SETTING, METHODS An in vitro assay was developed using RL95-2 (a human endometrial cell line) and JAr (a human trophoblast cell line) cells. Initially, the percentage of attached JAr spheroids to RL95-2 was measured in response to TLR 3 activation. Next, actin polymerization in RL95-2 cells was assessed in response to TLR 2/6, 3 and 5 activation. Phalloidin was used to assess the mean fluorescence intensity of F-actin by flow cytometry or confocal microscopy. Secondly, the influence of TLR 2/6, 3 and 5 activation on the expression of cluster of differentiation 98 (CD98) and β3 integrin was determined. To further understand through which pathways the TLR 3-induced alterations occur, inhibitors were applied for Toll/interleukin-1 receptor domain-containing adaptor inducing interferon-beta (TRIF), myeloid differentiation primary response 88 (MYD88), mitogen-activated protein kinases (MAPK) and nuclear factor pathways. MAIN RESULTS AND THE ROLE OF CHANCE We observed that stimulation of TLR 3 in endometrial cells with different concentrations of Poly I:C led to a reduction in the percentage of trophoblasts attached to the endometrial cells in a dose-dependent manner (P < 0.05). This decrease was consistent in the Poly I:C treated group regardless of the co-incubation time (P < 0.05). In addition, our results demonstrated that actin polymerization and CD98 expression significantly decreased only in response to TLR 3 activation (P < 0.05). Activation of endometrial cells with TLR 2/6, 3 and 5 significantly reduced β3 integrin expression (P < 0.05). These alterations were shown to work via MYD88-MAPK pathways (P < 0.05). LIMITATIONS, REASONS FOR CAUTION This study has been performed in vitro. Future in vivo studies will be required in order to confirm our data. WIDER IMPLICATIONS OF THE FINDINGS This is a novel discovery which extends our current knowledge concerning diagnosis and treatment of viral-induced infertility cases. STUDY FUNDING/COMPETING INTERESTS This research was supported by the COST Action FA1201 (GEMINI) by granting a Short Term Scientific Mission and the Instituto de Salud Carlos III by granting Grant PI11/01645. The authors have no conflict of interest to declare.
Collapse
Affiliation(s)
- M Montazeri
- Academic Unit of Reproductive and Developmental Medicine, The University of Sheffield, Level 4, Jessop Wing, Tree Root Walk, Sheffield S10 2SF, UK
| | - J A Sanchez-Lopez
- Academic Unit of Reproductive and Developmental Medicine, The University of Sheffield, Level 4, Jessop Wing, Tree Root Walk, Sheffield S10 2SF, UK
| | - I Caballero
- Academic Unit of Reproductive and Developmental Medicine, The University of Sheffield, Level 4, Jessop Wing, Tree Root Walk, Sheffield S10 2SF, UK UMR1282 ISP, INRA, Nouzilly, France
| | - N Maslehat Lay
- Academic Unit of Reproductive and Developmental Medicine, The University of Sheffield, Level 4, Jessop Wing, Tree Root Walk, Sheffield S10 2SF, UK
| | - S Elliott
- Academic Unit of Reproductive and Developmental Medicine, The University of Sheffield, Level 4, Jessop Wing, Tree Root Walk, Sheffield S10 2SF, UK
| | - S López-Martín
- Unidad de Investigación, Hospital Santa Cristina, Instituto de Investigación Sanitaria Princesa, C/Maestro Amadeo Vives 2, 28009 Madrid, Spain
| | - M Yáñez-Mó
- Unidad de Investigación, Hospital Santa Cristina, Instituto de Investigación Sanitaria Princesa, C/Maestro Amadeo Vives 2, 28009 Madrid, Spain
| | - A Fazeli
- Academic Unit of Reproductive and Developmental Medicine, The University of Sheffield, Level 4, Jessop Wing, Tree Root Walk, Sheffield S10 2SF, UK
| |
Collapse
|
15
|
Schmid A, Kopp A, Hanses F, Karrasch T, Schäffler A. C1q/TNF-related protein-3 (CTRP-3) attenuates lipopolysaccharide (LPS)-induced systemic inflammation and adipose tissue Erk-1/-2 phosphorylation in mice in vivo. Biochem Biophys Res Commun 2014; 452:8-13. [PMID: 24996172 DOI: 10.1016/j.bbrc.2014.06.054] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 06/11/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND The C1q/TNF-related proteins comprise a growing family of adiponectin paralogous proteins. CTRP-3 represents a novel adipokine with strong expression in adipose tissue and was shown to inhibit chemokine and cytokine release in adipocytes and monocytes in vitro. The aim of the study was to gain the proof of principle that CTRP-3 is a potent anti-inflammatory adipokine in vivo. METHODS C57BL/6N mice were treated intraperitoneally (i.p.) with bacterial lipopolysaccharide (LPS) for 2h. The effects of a 30 min pre-treatment with CTRP-3 i.p. or intravenously (i.v.) on systemic and on epididymal, perirenal and subcutaneous adipose tissue inflammation was analyzed via real-time RT-PCR, ELISA and Western blot analysis. RESULTS LPS (1 μg i.p.) significantly increased serum IL-6 and MIP-2 levels as well as epididymal adipose tissue expression of IL-6 and MIP-2 in mice, whereas CTRP-3 (10 μg i.p.) alone or PBS (i.p.) had no effect. Pre-treatment of mice by CTRP-3 i.p. prior to LPS application significantly attenuated LPS-induced cytokine levels but had no effect on adipose tissue cytokine mRNA expression. In contrast to i.p. application of CTRP-3, systemic i.v. application was not sufficient to inhibit LPS-induced cytokine levels or mRNA tissue expression. CTRP-3 given i.p. significantly attenuated LPS-induced phosphorylation of Erk-1/-2 in inguinal adipose tissue. CONCLUSION The present study shows the proof of principle that the novel adipokine CTRP-3 is a potent inhibitor of LPS-induced systemic inflammation and LPS-induced signaling in adipose tissue in vivo.
Collapse
Affiliation(s)
- Andreas Schmid
- Department of Internal Medicine III, Giessen University Hospital, Germany.
| | - Andrea Kopp
- Department of Internal Medicine I, Regensburg University Hospital, Germany
| | - Frank Hanses
- Department of Internal Medicine I, Regensburg University Hospital, Germany
| | - Thomas Karrasch
- Department of Internal Medicine III, Giessen University Hospital, Germany
| | - Andreas Schäffler
- Department of Internal Medicine III, Giessen University Hospital, Germany
| |
Collapse
|
16
|
Horton F, Wright J, Smith L, Hinton PJ, Robertson MD. Increased intestinal permeability to oral chromium (51 Cr) -EDTA in human Type 2 diabetes. Diabet Med 2014; 31:559-63. [PMID: 24236770 DOI: 10.1111/dme.12360] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/17/2013] [Accepted: 11/12/2013] [Indexed: 02/07/2023]
Abstract
OBJECTIVE In animal models of obesity and Type 2 diabetes, permeability of the intestine is increased because of impairment of tight junction proteins, allowing translocation of bacterial endotoxin and resulting in low-grade systemic inflammation. This has yet to be demonstrated in humans. The objective of this study was the demonstration of increased intestinal permeability in human Type 2 diabetes. METHODS We examined intestinal permeability using chromium ((51) Cr)-EDTA urinary recovery in twenty well-controlled men with Type 2 diabetes compared with control subjects matched for age, gender and BMI. RESULTS Intestinal permeability was significantly increased (P = 0.002) in the diabetic group and was correlated to increased levels of systemic inflammatory markers high-sensitivity C-reactive protein (r = 0.694, P = 0.001), interleukin 6 (r = 0.548, P = 0.012) and tumour necrosis factor alpha (r = 0.564, P = 0.010). CONCLUSION This is the first demonstration that increased intestinal permeability may be a feature of human Type 2 diabetes.
Collapse
Affiliation(s)
- F Horton
- Department of Nuclear Medicine, Royal Surrey County Hospital, Guildford, UK
| | | | | | | | | |
Collapse
|
17
|
Rosell M, Kaforou M, Frontini A, Okolo A, Chan YW, Nikolopoulou E, Millership S, Fenech ME, MacIntyre D, Turner JO, Moore JD, Blackburn E, Gullick WJ, Cinti S, Montana G, Parker MG, Christian M. Brown and white adipose tissues: intrinsic differences in gene expression and response to cold exposure in mice. Am J Physiol Endocrinol Metab 2014; 306:E945-64. [PMID: 24549398 PMCID: PMC3989735 DOI: 10.1152/ajpendo.00473.2013] [Citation(s) in RCA: 265] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Brown adipocytes dissipate energy, whereas white adipocytes are an energy storage site. We explored the plasticity of different white adipose tissue depots in acquiring a brown phenotype by cold exposure. By comparing cold-induced genes in white fat to those enriched in brown compared with white fat, at thermoneutrality we defined a "brite" transcription signature. We identified the genes, pathways, and promoter regulatory motifs associated with "browning," as these represent novel targets for understanding this process. For example, neuregulin 4 was more highly expressed in brown adipose tissue and upregulated in white fat upon cold exposure, and cell studies showed that it is a neurite outgrowth-promoting adipokine, indicative of a role in increasing adipose tissue innervation in response to cold. A cell culture system that allows us to reproduce the differential properties of the discrete adipose depots was developed to study depot-specific differences at an in vitro level. The key transcriptional events underpinning white adipose tissue to brown transition are important, as they represent an attractive proposition to overcome the detrimental effects associated with metabolic disorders, including obesity and type 2 diabetes.
Collapse
Affiliation(s)
- Meritxell Rosell
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Kruis T, Batra A, Siegmund B. Bacterial translocation - impact on the adipocyte compartment. Front Immunol 2014; 4:510. [PMID: 24432024 PMCID: PMC3881001 DOI: 10.3389/fimmu.2013.00510] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 12/24/2013] [Indexed: 12/29/2022] Open
Abstract
Over the last decade it became broadly recognized that adipokines and thus the fat tissue compartment exert a regulatory function on the immune system. Our own group described the pro-inflammatory function of the adipokine leptin within intestinal inflammation in a variety of animal models. Following-up on this initial work, the aim was to reveal stimuli and mechanisms involved in the activation of the fat tissue compartment and the subsequent release of adipokines and other mediators paralleled by the infiltration of immune cells. This review will summarize the current literature on the possible role of the mesenteric fat tissue in intestinal inflammation with a focus on Crohn’s disease (CD). CD is of particular interest in this context since the transmural intestinal inflammation has been associated with a characteristic hypertrophy of the mesenteric fat, a phenomenon called “creeping fat.” The review will address three consecutive questions: (i) What is inducing adipocyte activation, (ii) which factors are released after activation and what are the consequences for the local fat tissue compartment and infiltrating cells; (iii) do the answers generated before allow for an explanation of the role of the mesenteric fat tissue within intestinal inflammation? With this review we will provide a working model indicating a close interaction in between bacterial translocation, activation of the adipocytes, and subsequent direction of the infiltrating immune cells. In summary, the models system mesenteric fat indicates a unique way how adipocytes can directly interact with the immune system.
Collapse
Affiliation(s)
- Tassilo Kruis
- Department of Medicine I (Gastroenterology, Rheumatology, Infectious Diseases), Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Arvind Batra
- Department of Medicine I (Gastroenterology, Rheumatology, Infectious Diseases), Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Britta Siegmund
- Department of Medicine I (Gastroenterology, Rheumatology, Infectious Diseases), Charité - Universitätsmedizin Berlin , Berlin , Germany
| |
Collapse
|