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Guerrero-Romero F, Castellanos-Juárez FX, Salas-Pacheco JM, Morales-Gurrola FG, Salas-Leal AC, Simental-Mendía LE. Association between the expression of TLR4, TLR2, and MyD88 with low-grade chronic inflammation in individuals with metabolically healthy obesity. Mol Biol Rep 2023; 50:4723-4728. [PMID: 36905405 DOI: 10.1007/s11033-023-08338-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 02/15/2023] [Indexed: 03/12/2023]
Abstract
BACKGROUND Among the Toll-like receptors (TLR) that are dependent of myeloid response protein (MyD88), the TLR4 and TLR2 are directly associated with low-grade chronic inflammation; however, they are not been investigated in subjects with metabolically healthy obesity (MHO). Thus, the objective of this study was to determine the association between the expression of TLR4, TLR2, and MyD88 with low-grade chronic inflammation in individuals with MHO. METHODS AND RESULTS Men and women with obesity aged 20 to 55 years were enrolled in a cross-sectional study. Individuals with MHO were allocated into the groups with and without low-grade chronic inflammation. Pregnancy, smoking, alcohol consumption, intense physical activity or sexual intercourse in the previous 72 h, diabetes, high blood pressure, cancer, thyroid disease, acute or chronic infections, renal impairment, and hepatic diseases, were exclusion criteria. The MHO phenotype was defined by a body mass index (BMI ≥ 30 kg/m2) plus one or none of the following cardiovascular risk factors: hyperglycemia, elevated blood pressure, hypertriglyceridemia, and low high-density lipoprotein cholesterol. A total of 64 individuals with MHO were enrolled and allocated into the groups with (n = 37) and without (n = 27) inflammation. The multiple logistic regression analysis indicated that TLR2 expression is significantly associated with inflammation in individuals with MHO. In the subsequent analysis adjusted by BMI, TLR2 expression remained associated with inflammation in individuals with MHO. CONCLUSION Our results suggest that overexpression of TLR2, but not TLR4 and MyD88, is associated with low-grade chronic inflammation in subjects with MHO.
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Affiliation(s)
- Fernando Guerrero-Romero
- Unidad de Investigación Biomédica, Instituto Mexicano del Seguro Social, Predio Canoas 100, Col. Los Angeles, 34077, Durango, Dgo, Mexico
| | | | - Jose M Salas-Pacheco
- Institute of Scientific Research, Juarez University of the State of Durango, Durango, México
| | - Francisco G Morales-Gurrola
- Unidad de Investigación Biomédica, Instituto Mexicano del Seguro Social, Predio Canoas 100, Col. Los Angeles, 34077, Durango, Dgo, Mexico.,Institute of Scientific Research, Juarez University of the State of Durango, Durango, México
| | | | - Luis E Simental-Mendía
- Unidad de Investigación Biomédica, Instituto Mexicano del Seguro Social, Predio Canoas 100, Col. Los Angeles, 34077, Durango, Dgo, Mexico.
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2
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Abstract
Statins are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors used worldwide to manage dyslipidaemia and thus limit the development of atherosclerotic disease and its complications. These atheroprotective drugs are now known to exert pleiotropic actions outside of their cholesterol-lowering activity, including altering immune cell function. Macrophages are phagocytic leukocytes that play critical functional roles in the pathogenesis of atherosclerosis and are directly targeted by statins. Early studies documented the anti-inflammatory effects of statins on macrophages, but emerging evidence suggests that these drugs can also enhance pro-inflammatory macrophage responses, creating an unresolved paradox. This review comprehensively examines the in vitro, in vivo, and clinical literature to document the statin-induced changes in macrophage polarization and immunomodulatory functions, explore the underlying mechanisms involved, and offer potential explanations for this paradox. A better understanding of the immunomodulatory actions of statins on macrophages should pave the way for the development of novel therapeutic approaches to manage atherosclerosis and other chronic diseases and conditions characterised by unresolved inflammation.
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Zheng Y, Lv P, Huang J, Ke J, Yan J. GYY4137 exhibits anti-atherosclerosis effect in apolipoprotein E (-/-) mice via PI3K/Akt and TLR4 signalling. Clin Exp Pharmacol Physiol 2020; 47:1231-1239. [PMID: 32144792 DOI: 10.1111/1440-1681.13298] [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: 11/17/2019] [Revised: 02/26/2020] [Accepted: 03/03/2020] [Indexed: 12/12/2022]
Abstract
Hydrogen sulphide (H2 S) had been suggested to be involved in the pathogenesis of atherosclerosis, but the underlying molecular mechanisms are poorly understood. In this study, we aimed to investigate the anti-atherosclerosis effect of morpholin-4-ium-methoxyphenyl-morpholino-phosphinodithioate (GYY4137) in RAW264.7 cell-derived foam cells formation and in the atherosclerotic plaque of ApoE-/- mice fed with a high-fat diet, and study the underlying mechanisms of phosphatidylinositol 3-kinase (PI3K), serine/ threonine kinase (Akt) and Toll-like receptor 4 (TLR4) signalling pathway. In the ApoE-/- mice fed with a high-fat diet, daily GYY4137 administration for 8 weeks effectively decreased carotid atherosclerotic plaque area and the volume of foam cells, regulated the lipid metabolism, down-regulated the pro-inflammatory cytokine levels and up-regulated the anti-inflammatory cytokines levels. Consistent with these findings, in the RAW264.7 cell-derived foam cells, GYY4137 ameliorated foam cell formation in vitro, and decreased the expression of pro-inflammatory cytokines. Furthermore, our studies showed that GYY4137 could activate the PI3K/Akt signalling pathway and consequently reduce the expression of TLR4 to be critical for foam cell formation, preventing atherosclerotic plaque formation and destabilization. LY294002, a PI3K inhibitor, could inhibit the phosphorylation of Akt and reduce the expression of TLR4, thus reduce the foam cell source and lipid volume in the unstable plaque tissue. Our results suggest that GYY4137 is an attractive novel therapeutic reagent for atherosclerosis diseases. This mechanism may be partially attributed to regulating the PI3K/Akt/TLR4 signalling pathway.
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Affiliation(s)
- Yaofu Zheng
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Ping Lv
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jun Huang
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Junsong Ke
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jumei Yan
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, China
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Immune-Mediated Inflammation in Vulnerable Atherosclerotic Plaques. Molecules 2019; 24:molecules24173072. [PMID: 31450823 PMCID: PMC6749340 DOI: 10.3390/molecules24173072] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/21/2019] [Accepted: 08/22/2019] [Indexed: 01/16/2023] Open
Abstract
Atherosclerosis is a chronic long-lasting vascular disease leading to myocardial infarction and stroke. Vulnerable atherosclerotic (AS) plaques are responsible for these life-threatening clinical endpoints. To more successfully work against atherosclerosis, improvements in early diagnosis and treatment of AS plaque lesions are required. Vulnerable AS plaques are frequently undetectable by conventional imaging because they are non-stenotic. Although blood biomarkers like lipids, C-reactive protein, interleukin-6, troponins, and natriuretic peptides are in pathological ranges, these markers are insufficient in detecting the critical perpetuation of AS anteceding endpoints. Thus, chances to treat the patient in a preventive way are wasted. It is now time to solve this dilemma because clear results indicate a benefit of anti-inflammatory therapy per se without modification of blood lipids (CANTOS Trial, NCT01327846). This fact identifies modulation of immune-mediated inflammation as a new promising point of action for the eradication of fatal atherosclerotic endpoints.
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5
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Badr RE, Salama MI, Abd-Elmaogood AK, Eldeib AERM. Toll-like receptor 2 expression on monocytes and microvascular complications in type 2 diabetic patients. Diabetes Metab Syndr 2019; 13:1299-1302. [PMID: 31336481 DOI: 10.1016/j.dsx.2019.01.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 12/15/2018] [Accepted: 01/22/2019] [Indexed: 11/18/2022]
Abstract
UNLABELLED Diabetes mellitus (DM) is a chronic debilitating illness, and atherosclerotic changes are inevitable and usually neglected during the follow-up of diabetic patients. Toll-like receptor 2 (TLR2) is under trial in many studies to hold responsibility for atherosclerosis process progression as they suggest a malfunction of these receptors expressed on monocytes in diabetic patients. This study aimed to assess the association between the TLR2 and type 2 diabetes mellitus (T2DM) in Egyptian diabetic patients and to investigate its relationship with some diabetic complications. METHODS This study included a 60 diabetic patients group 1 (diabetic complicated), group 2 (diabetic non-complicated) and 30 age-matched normal healthy blood donors. RESULTS Toll-like receptors (TLRs) expression was significantly associated with T2DM. In this study, the mean fluorescent intensity (MFI) of TLR2 was 596.9 ± 84.78 in group 1, 326.23 ± 62.98 in group 2 while in group 3 it was 208.47 ± 156.73. There was a significant correlation between MFI of TLR2 and random blood sugar (RBS) and glycated haemoglobin (HbA1c) (p < 0.05). CONCLUSION TLR2 was overexpressed in diabetic patients with microvascular complications compared to diabetic non-complicated patients and normal healthy controls.
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Affiliation(s)
- Rasha Emad Badr
- Lecturer of Clinical and Chemical Pathology Department, Faculty of Medicine, Portsaid University, Portsaid, Egypt.
| | - Mona Ibrahim Salama
- Lecturer of Clinical and Chemical Pathology Department, Faculty of Medicine, Portsaid University, Portsaid, Egypt
| | - Asmaa Kamal Abd-Elmaogood
- Lecturer of Clinical and Chemical Pathology Department, Faculty of Medicine, Suez Canal University, Egypt
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6
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Tian D, Sha Y, Lu JM, Du XJ. MiR-370 inhibits vascular inflammation and oxidative stress triggered by oxidized low-density lipoprotein through targeting TLR4. J Cell Biochem 2018; 119:6231-6237. [PMID: 29663491 DOI: 10.1002/jcb.26851] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/09/2018] [Indexed: 12/21/2022]
Abstract
Atherosclerosis, as a chronic cardiovascular disease, still remains a serious threat to human health. Inflammation and oxidative stress are commonly involved in various stages of atherosclerosis development. MicroRNAs are reported to play important roles in macrophages, which can respond to inflammation and oxidative stress. In our current study, we focused on the biological roles of miR-370 in atherosclerosis. According to the previously research, miR-370 was downregulated in AS mice models. Oxidized low-density lipoprotein (Ox-LDL) is regarded as a crucial regulator of atherosclerosis and we observed that miR-370 was decreased by ox-LDL dose-dependently and time-dependently in THP-1 cells. Then, it was found that miR-370 overexpression was able to inhibit inflammation molecules including IL-6 and IL-1β. Meanwhile, ROS levels, and malondialdehyde (MDA) were also restrained by miR-370 mimics in vitro. Toll-like receptor 4 (TLR4) has been implicated in many inflammation diseases. It can serve as a target of miR-370 and TLR4 expression was greatly increased in ox-LDL-incubated THP-1 cells in a time and dose dependent manner. The negative correlation was validated using a dual-luciferase reporter assay in our study. In conclusion, our present study revealed that miR-370 can reduce inflammatory reaction and inhibit the ROS production by targeting TLR4 in THP-1 cells.
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Affiliation(s)
- Dan Tian
- Department of Emergency, Renmin Hospital of Wuhan University, Wuchang, Wuhan, China
| | - Yin Sha
- Department of Neurology, Huai'an Second People's Hospital, The Affiliated Huai'an Hospital of Xuzhou Medical University, Huai'an,, China
| | - Jing-Min Lu
- Department of Neurology, Huai'an Second People's Hospital, The Affiliated Huai'an Hospital of Xuzhou Medical University, Huai'an,, China
| | - Xian-Jin Du
- Department of Emergency, Renmin Hospital of Wuhan University, Wuchang, Wuhan, China
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Abstract
PURPOSE OF REVIEW The present review explores the mechanisms of superficial intimal erosion, a common cause of thrombotic complications of atherosclerosis. RECENT FINDINGS Human coronary artery atheroma that give rise to thrombosis because of erosion differ diametrically from those associated with fibrous cap rupture. Eroded lesions characteristically contain few inflammatory cells, abundant extracellular matrix, and neutrophil extracellular traps (NETs). Innate immune mechanisms such as engagement of Toll-like receptor 2 (TLR2) on cultured endothelial cells can impair their viability, attachment, and ability to recover a wound. Hyaluronan fragments may serve as endogenous TLR2 ligands. Mouse experiments demonstrate that flow disturbance in arteries with neointimas tailored to resemble features of human eroded plaques disturbs endothelial cell barrier function, impairs endothelial cell viability, recruits neutrophils, and provokes endothelial cells desquamation, NET formation, and thrombosis in a TLR2-dependent manner. SUMMARY Mechanisms of erosion have received much less attention than those that provoke plaque rupture. Intensive statin treatment changes the characteristic of plaques that render them less susceptible to rupture. Thus, erosion may contribute importantly to the current residual burden of risk. Understanding the mechanisms of erosion may inform the development and deployment of novel therapies to combat the remaining atherothrombotic risk in the statin era.
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Affiliation(s)
- Thibaut Quillard
- Department of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Grégory Franck
- Department of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Thomas Mawson
- Department of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Eduardo Folco
- Department of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Peter Libby
- Department of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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8
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Cai J, Zhong H, Wu J, Chen RF, Yang H, Al-Abed Y, Li Y, Li X, Jiang W, Montenegro MF, Yuan H, Billiar TR, Chen AF. Cathepsin L promotes Vascular Intimal Hyperplasia after Arterial Injury. Mol Med 2017; 23:92-100. [PMID: 28332696 PMCID: PMC5468173 DOI: 10.2119/molmed.2016.00222] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 03/15/2017] [Indexed: 01/02/2023] Open
Abstract
The inflammatory pathways that drive the development of intimal hyperplasia (IH) following arterial injury are not fully understood. We hypothesized that the lysosomal cysteine protease cathepsin L activates processes leading to IH after arterial injury. Using a mouse model of wire-induced carotid artery injury we showed that cathepsin L activity peaks at day 7 and remains elevated to 28 days. The genetic deletion of cathepsin L prevented IH and monocyte recruitment in the carotid wall. The injury-induced increases in cathepsin L mRNA and activity were mitigated in mice with myeloid-specific deletion of toll like receptor 4 (TLR4) or myeloid differentiation primary response gene 88 (MyD88). We further discovered that a HIV-protease inhibitor saquinavir (SQV), which is known to block recombinant mouse cathepsin L activity in vitro, prevented IH after arterial injury. SQV also suppressed LPS (TLR4 agonist) induced monocyte adhesion to endothelial monolayers. These findings establish cathepsin L as a critical regulator of the inflammation that leads to IH and that the TLR4- MyD88 pathway in myeloid lineages regulates cathepsin L expression in the vessel wall following wire injury. The FDA approved drug, SQV blocks IH though mechanisms that may include the suppression of cathepsin L.
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Affiliation(s)
- Jingjing Cai
- Center for Vascular Disease and Translational Medicine, Third Xiangya Hospital, Central South University, Changsha, China
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Department of Cardiology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Hua Zhong
- Center for Vascular Disease and Translational Medicine, Third Xiangya Hospital, Central South University, Changsha, China
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Jinze Wu
- Center for Vascular Disease and Translational Medicine, Third Xiangya Hospital, Central South University, Changsha, China
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Rui-Fang Chen
- Center for Vascular Disease and Translational Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Huan Yang
- The Feinstein Institute for Medical Research, Manhasset, New York, United States of America
| | - Yousef Al-Abed
- The Feinstein Institute for Medical Research, Manhasset, New York, United States of America
| | - Ying Li
- Center for Vascular Disease and Translational Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiaohui Li
- Center for Vascular Disease and Translational Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Weihong Jiang
- Department of Cardiology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Marcelo F Montenegro
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Hong Yuan
- Center for Vascular Disease and Translational Medicine, Third Xiangya Hospital, Central South University, Changsha, China
- Department of Cardiology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Timothy R Billiar
- Center for Vascular Disease and Translational Medicine, Third Xiangya Hospital, Central South University, Changsha, China
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Alex F Chen
- Center for Vascular Disease and Translational Medicine, Third Xiangya Hospital, Central South University, Changsha, China
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Department of Cardiology, Third Xiangya Hospital, Central South University, Changsha, China
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9
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Perry CJ, Blake P, Buettner C, Papavassiliou E, Schain AJ, Bhasin MK, Burstein R. Upregulation of inflammatory gene transcripts in periosteum of chronic migraineurs: Implications for extracranial origin of headache. Ann Neurol 2016; 79:1000-13. [PMID: 27091721 DOI: 10.1002/ana.24665] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 03/29/2016] [Accepted: 04/07/2016] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Chronic migraine (CM) is often associated with chronic tenderness of pericranial muscles. A distinct increase in muscle tenderness prior to onset of occipital headache that eventually progresses into a full-blown migraine attack is common. This experience raises the possibility that some CM attacks originate outside the cranium. The objective of this study was to determine whether there are extracranial pathophysiologies in these headaches. METHODS We biopsied and measured the expression of gene transcripts (mRNA) encoding proteins that play roles in immune and inflammatory responses in affected (ie, where the head hurts) calvarial periosteum of (1) patients whose CMs are associated with muscle tenderness and (2) patients with no history of headache. RESULTS Expression of proinflammatory genes (eg, CCL8, TLR2) in the calvarial periosteum significantly increased in CM patients attesting to muscle tenderness, whereas expression of genes that suppress inflammation and immune cell differentiation (eg, IL10RA, CSF1R) decreased. INTERPRETATION Because the upregulated genes were linked to activation of white blood cells, production of cytokines, and inhibition of NF-κB, and the downregulated genes were linked to prevention of macrophage activation and cell lysis, we suggest that the molecular environment surrounding periosteal pain fibers is inflamed and in turn activates trigeminovascular nociceptors that reach the affected periosteum through suture branches of intracranial meningeal nociceptors and/or somatic branches of the occipital nerve. This study provides the first set of evidence for localized extracranial pathophysiology in CM. Ann Neurol 2016;79:1000-1013.
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Affiliation(s)
| | - Pamela Blake
- Headache Center of Greater Heights, Memorial Hermann Greater Heights Hospital, Houston, TX
| | - Catherine Buettner
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA.,Harvard Medical School, Boston, MA
| | - Efstathios Papavassiliou
- Harvard Medical School, Boston, MA.,Department of Surgery, Beth Israel Deaconess Medical Center, Boston, MA
| | - Aaron J Schain
- Harvard Medical School, Boston, MA.,Department of Anesthesia and Critical Care, Beth Israel Deaconess Medical Center, Boston, MA
| | - Manoj K Bhasin
- Harvard Medical School, Boston, MA.,Division of Genomics, Proteomics, Bioinformatics, and Systems Biology, Beth Israel Deaconess Medical Center, Boston, MA
| | - Rami Burstein
- Harvard Medical School, Boston, MA.,Department of Anesthesia and Critical Care, Beth Israel Deaconess Medical Center, Boston, MA
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Lekva T, Norwitz ER, Aukrust P, Ueland T. Impact of Systemic Inflammation on the Progression of Gestational Diabetes Mellitus. Curr Diab Rep 2016; 16:26. [PMID: 26879309 DOI: 10.1007/s11892-016-0715-9] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
With increasing rates of obesity and new diagnostic criteria for gestational diabetes mellitus (GDM), the overall prevalence of GDM is increasing worldwide. Women with GDM have an increased risk of maternal and fetal complications during pregnancy as well as long-term risks including higher prevalence of type 2 diabetes mellitus and cardiovascular disease. In recent years, the role of immune activation and inflammation in the pathogenesis of GDM has gained increasing attention. This monograph explores the current state of the literature as regards the expression of markers of inflammation in the maternal circulation, placenta, and adipose tissue of women with GDM.
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Affiliation(s)
- Tove Lekva
- Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, Sognsvannsveien 20, 0027, Oslo, Norway.
- Mother Infant Research Institute, Tufts Medical Center, 800 Washington Street, Boston, MA, 02116, USA.
| | - Errol R Norwitz
- Mother Infant Research Institute, Tufts Medical Center, 800 Washington Street, Boston, MA, 02116, USA.
- Department of Obstetrics & Gynecology, Tufts Medical Center and Tufts University School of Medicine, Boston, MA, USA.
| | - Pål Aukrust
- Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, Sognsvannsveien 20, 0027, Oslo, Norway.
- Faculty of Medicine, University of Oslo, Oslo, Norway.
- Section of Clinical Immunology and Infectious Diseases, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
| | - Thor Ueland
- Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, Sognsvannsveien 20, 0027, Oslo, Norway.
- Faculty of Medicine, University of Oslo, Oslo, Norway.
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miR-223 Inhibits Lipid Deposition and Inflammation by Suppressing Toll-Like Receptor 4 Signaling in Macrophages. Int J Mol Sci 2015; 16:24965-82. [PMID: 26492242 PMCID: PMC4632784 DOI: 10.3390/ijms161024965] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Revised: 09/04/2015] [Accepted: 09/20/2015] [Indexed: 12/16/2022] Open
Abstract
Atherosclerosis and its complications rank as the leading cause of death with the hallmarks of lipid deposition and inflammatory response. MicroRNAs (miRNAs) have recently garnered increasing interests in cardiovascular disease. In this study, we investigated the function of miR-223 and the underlying mechanism in atherosclerosis. In the atherosclerotic ApoE−/− mice models, an obvious increase of miR-223 was observed in aortic atherosclerotic lesions. In lipopolysaccharide (LPS) activated macrophages, its expression was decreased. The miR-223 overexpression significantly attenuated macrophage foam cell formation, lipid accumulation and pro-inflammatory cytokine production, which were reversed by anti-miR-223 inhibitor transfection. Mechanism assay corroborated that miR-223 negatively regulated the activation of the toll-like receptor 4 (TLR4)-nuclear factor-κB (NF-κB) pathway. Pretreatment with a specific inhibitor of NF-κB (pyrrolidinedithiocarbamate, PDTC) strikingly abrogated miR-223 silence-induced lipid deposition and inflammatory cytokine production. Furthermore, PI3K/AKT was activated by miR-223 up-regulation. Pretreatment with PI3K/AKT inhibitor LY294002 strikingly ameliorated the inhibitory effects of miR-223 on the activation of TLR4 and p65, concomitant with the increase in lipid deposition and inflammatory cytokine production. Together, these data indicate that miR-223 up-regulation might abrogate the development of atherosclerosis by blocking TLR4 signaling through activation of the PI3K/AKT pathway, and provides a promising therapeutic avenue for the treatment of atherosclerosis.
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Ziaei A, Hoppstädter J, Kiemer AK, Ramezani M, Amirghofran Z, Diesel B. Inhibitory effects of teuclatriol, a sesquiterpene from salvia mirzayanii, on nuclear factor-κB activation and expression of inflammatory mediators. JOURNAL OF ETHNOPHARMACOLOGY 2015; 160:94-100. [PMID: 25446581 DOI: 10.1016/j.jep.2014.10.041] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/10/2014] [Accepted: 10/21/2014] [Indexed: 05/21/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Salvia mirzayanii Rech. f. & Esfand. is an endemic plant, which is only distributed in the south of Iran. In traditional Iranian medicine, the aerial parts of Salvia mirzayanii have been used for infections, inflammatory diseases, and as a tonic. From this plant, the sesquiterpene teuclatriol was isolated by bioactivity-guided fractionation due to its anti-proliferative actions on human lymphocytes. The guaiane sesquiterpene is lacking the methylene-γ-lactone function that is typically involved in the inhibiting properties of sesquiterpenes on NF-κB, a pivotal transcription factor in inflammatory processes. We here investigated anti-inflammatory effects of teuclatriol on human macrophage-like and endothelial cells. MATERIALS AND METHODS Non-toxic doses of teuclatriol were determined for both cell types by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)-assay. The effect of teuclatriol on the activity of NF-κB in LPS-stimulated human monocytic THP-1 cells was studied using infrared electrophoretic mobility shift assay (IR-EMSA) using curcumin as positive control (32µM). THP-1 were differentiated into macrophage-like cells and evaluated for TNF-α secretion by L929 bioassay following stimulation with LPS and treatment with teuclatriol. Inflammatory gene expression in human umbilical vein endothelial cells (HUVEC), modeling target cells for TNF-α-induced inflammatory gene activation, was investigated by real-time RT-PCR. RESULTS The LPS-induced DNA binding activity of NF-κB in THP-1 was significantly decreased by non-toxic doses of teuclatriol (312 and 390µM). Teuclatriol reduced the production of TNF-α in a dose-dependent manner. mRNA levels of both monocyte chemoattractant protein (MCP)-1 and toll-like receptor (TLR)2 were decreased in TNF-α-activated HUVEC. CONCLUSION These data show an inhibitory effect of teuclatriol on NF-κB signaling at doses of 312µM and higher, validating the traditional use of Salvia mirzayanii in the treatment of inflammatory diseases. Future work on the mode of action of teuclatriol may provide new lead structures with NF-κB inhibiting properties, lacking possible side effects mediated via alkylating centers of sesquiterpene lactones.
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Affiliation(s)
- Akram Ziaei
- Department of Immunology, Dr. Sheikh Educational, Research and Treatment Hospital, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Jessica Hoppstädter
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken, Germany
| | - Alexandra K Kiemer
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken, Germany
| | - Mohammad Ramezani
- Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Zahra Amirghofran
- Immunology Department, Autoimmune Disease Research Center, Medicinal and Natural Products Chemistry Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Britta Diesel
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken, Germany
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13
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Xie BG, Jin S, Zhu WJ. Expression of toll-like receptor 4 in maternal monocytes of patients with gestational diabetes mellitus. Exp Ther Med 2013; 7:236-240. [PMID: 24348797 PMCID: PMC3861517 DOI: 10.3892/etm.2013.1360] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 10/21/2013] [Indexed: 12/16/2022] Open
Abstract
Toll-like receptors (TLRs) are pattern recognition receptors and play an important role in innate immune responses and the occurrence of inflammatory disease. TLR4 is a member of the TLR family and its activation is capable of inducing inflammatory responses, reflecting a relationship between the innate and adaptive immune systems. However, whether TLR4 is expressed in patients with gestational diabetes mellitus (GDM) has not been elucidated. The aim of the present study was to investigate whether TLR4 is expressed in maternal peripheral blood monocytes of patients with GDM. A case-control study, using standard quantitative polymerase chain reaction and western blotting, was performed to assess the TLR4 expression in 30 females with GDM and 32 healthy pregnant females at similar gestational ages. Serum tumor necrosis factor (TNF)-α levels were assessed using ELISA in all the females. The TLR4 expression levels in the maternal peripheral blood monocytes and the serum TNF-α levels were increased in females with GDM compared with healthy pregnant females (P<0.05). Additionally, there was a positive correlation between the TLR4 expression level in peripheral blood monocytes and serum TNF-α levels in all the females. These results indicate that TLR4-mediated release of inflammatory cytokines may represent one factor leading to increased glucose levels in patients with GDM. In addition, TLR4 may be involved in the pathogenesis of GDM.
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Affiliation(s)
- Bao-Guo Xie
- Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Song Jin
- Department of Obstetrics and Gynecology, Affiliated Hospital of Hainan Medical College, Haikou, Hainan 570102, P.R. China
| | - Wei-Jie Zhu
- Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangzhou, Guangdong 510632, P.R. China
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Amaya-Amaya J, Sarmiento-Monroy JC, Mantilla RD, Pineda-Tamayo R, Rojas-Villarraga A, Anaya JM. Novel risk factors for cardiovascular disease in rheumatoid arthritis. Immunol Res 2013; 56:267-86. [DOI: 10.1007/s12026-013-8398-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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15
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Shaik-Dasthagirisaheb YB, Huang N, Baer MT, Gibson FC. Role of MyD88-dependent and MyD88-independent signaling in Porphyromonas gingivalis-elicited macrophage foam cell formation. Mol Oral Microbiol 2013; 28:28-39. [PMID: 23194377 PMCID: PMC3543481 DOI: 10.1111/omi.12003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2012] [Indexed: 12/13/2022]
Abstract
Clinical studies and experimental modeling identify a potential link between periodontal disease and periodontal pathogens such as Porphyromonas gingivalis and atherosclerosis and formation of macrophage foam cells. Toll-like receptors and molecules governing their intracellular signaling pathways such as MyD88 play roles in atherosclerosis, as well as host response to P. gingivalis. The aim of this study was to define roles of MyD88 and TRIF during macrophage foam cell formation in response to P. gingivalis. In the presence of human low-density lipoprotein (LDL) mouse bone-marrow-derived macrophages (BMφ) cultured with P. gingivalis responded with significant reduction in tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). The BMφ stained strongly with oil red O, regardless of whether bacterial challenge occurred concurrent with or before LDL treatment. Heat-killed P. gingivalis stimulated foam cell formation in a similar way to live bacteria. The BMφ from MyD88-knockout and Lps2 mice revealed a significant role for MyD88, and a minor role for TRIF in P. gingivalis-elicited foam cell formation. Porphyromonas gingivalis-elicited TNF-α and IL-6 were affected by MyD88 ablation and to a lesser extent by TRIF status. These data indicate that LDL affects the TNF-α and IL-6 response of macrophages to P. gingivalis challenge and that MyD88 and TRIF play important roles in P. gingivalis-elicited foam cell formation.
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Affiliation(s)
| | - Nasi Huang
- Section of Infectious Diseases, Department of Medicine, Boston University Medical Center, Boston, MA 02118
| | | | - Frank C. Gibson
- Section of Infectious Diseases, Department of Medicine, Boston University Medical Center, Boston, MA 02118
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16
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Koutouzis T, Catania D, Neiva K, Wallet SM. Innate Immune Receptor Expression in Peri-Implant Tissues of Patients With Different Susceptibility to Periodontal Diseases. J Periodontol 2013; 84:221-9. [DOI: 10.1902/jop.2012.120061] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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17
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Chen YY, Chen J, Hu JW, Yang ZL, Shen YL. Enhancement of lipopolysaccharide-induced toll-like receptor 2 expression and inflammatory cytokine secretion in HUVECs under high glucose conditions. Life Sci 2013; 92:582-8. [PMID: 23369747 DOI: 10.1016/j.lfs.2013.01.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 12/05/2012] [Accepted: 01/15/2013] [Indexed: 12/11/2022]
Abstract
AIMS Endothelial inflammatory responses mediated by toll-like receptors (TLRs) play an important role in atherogenesis. We aimed to investigate the exacerbation of an inflammatory response in human umbilical vein endothelial cells (HUVECs) under high glucose conditions. MAIN METHODS HUVECs were exposed to normal glucose (5.5 mmol/L) and high glucose (25, 50 mmol/L), alone or with lipopolysaccharide (LPS 0, 10, 100, or 1000 μg/L). Then concentrations of TNF-α and IL-6 in the culture supernatants were determined. The expression of toll-like receptor 2 (TLR2), TLR4 and NF-κB was evaluated by Western blot and RT-PCR analysis. KEY FINDINGS Compared with the normal glucose group, exposure of HUVECs to 50 mmol/L of glucose or 1000 μg/L of LPS significantly increased the concentrations of TNF-α and IL-6 in the culture supernatants. Neither 25 mmol/L of glucose nor low concentration of LPS (≤100 μg/L) alone had an effect on TNF-α and IL-6 release, or TLR2 expression, but they stimulated the inflammatory response and TLR2 expression under high glucose conditions (25 mmol/L) in combination. LPS (100 μg/L) did not alter the TLR4 expression in HUVECs under high glucose condition. Co-incubation with glucose and LPS increased the nuclear NF-κB expression in endothelial cells. Both NF-κB inhibitor and ROS scavenger could inhibit the enhancement of LPS-induced TLR2 expression and inflammatory cytokine secretion under high glucose conditions. SIGNIFICANCE We show in vitro data on the potential role of high glucose in increasing LPS-induced TLR2 expression and inflammatory cytokine secretion in HUVECs, offering a new insight into the pathophysiological pathways involved in atherosclerosis.
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Affiliation(s)
- Ying-ying Chen
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou 310058, China
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18
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Reyna SM, Tantiwong P, Cersosimo E, DeFronzo RA, Sriwijitkamol A, Musi N. Short-term exercise training improves insulin sensitivity but does not inhibit inflammatory pathways in immune cells from insulin-resistant subjects. J Diabetes Res 2013; 2013:107805. [PMID: 23671849 PMCID: PMC3647562 DOI: 10.1155/2013/107805] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 01/16/2013] [Indexed: 12/31/2022] Open
Abstract
Background. Exercise has an anti-inflammatory effect against, and immune cells play critical roles in the development, of insulin resistance and atherosclerotic vascular disease (AVD). Thus, the goal of this study was to determine whether exercise improves insulin sensitivity in insulin-resistant subjects by downregulating proinflammatory signaling in immune cells. Methods. Seventeen lean, 8 obese nondiabetic, and 11 obese type 2 diabetic individuals underwent an aerobic exercise program for 15 days and an insulin clamp before and after exercise. Peripheral mononuclear cells (PMNC) were obtained for determination of Toll-like receptor (TLR) 2 and 4 protein content and mitogen-activated protein kinase phosphorylation. Results. Compared with that in lean individuals, TLR4 protein content was increased by 4.2-fold in diabetic subjects. This increase in TLR4 content was accompanied by a 3.0-fold increase in extracellular signal-regulated kinase (ERK) phosphorylation. Exercise improved insulin sensitivity in the lean, obese, and type 2 diabetes groups. However, exercise did not affect TLR content or ERK phosphorylation. Conclusions. TLR4 content and ERK phosphorylation are increased in PMNC of type 2 diabetic individuals. While exercise improves insulin sensitivity, this effect is not related to changes in TLR2/TLR4 content or ERK phosphorylation in PMNC of type 2 diabetic individuals.
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Affiliation(s)
- Sara M. Reyna
- Medical Research Division, Regional Academic Health Center, 1214 W. Schunior Street, Edinburg, TX 78541, USA
- Diabetes Division, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
- Texas Diabetes Institute, 701 S. Zarzamora, San Antonio, TX 78207, USA
| | - Puntip Tantiwong
- Diabetes Division, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
- Texas Diabetes Institute, 701 S. Zarzamora, San Antonio, TX 78207, USA
| | - Eugenio Cersosimo
- Diabetes Division, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
- Texas Diabetes Institute, 701 S. Zarzamora, San Antonio, TX 78207, USA
| | - Ralph A. DeFronzo
- Diabetes Division, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
- Texas Diabetes Institute, 701 S. Zarzamora, San Antonio, TX 78207, USA
| | - Apiradee Sriwijitkamol
- Diabetes Division, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Nicolas Musi
- Diabetes Division, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
- Texas Diabetes Institute, 701 S. Zarzamora, San Antonio, TX 78207, USA
- Geriatric, Research, Education, and Clinical Center, Audie L. Murphy VA Hospital, 7400 Merton Minter Boulevard, San Antonio, TX 78229, USA
- *Nicolas Musi:
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19
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Toll-like receptor activity in patients with obstructive sleep apnea. Sleep Breath 2012; 17:1009-16. [DOI: 10.1007/s11325-012-0791-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 11/22/2012] [Accepted: 11/23/2012] [Indexed: 10/27/2022]
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20
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Kaur H, Chien A, Jialal I. Hyperglycemia induces Toll like receptor 4 expression and activity in mouse mesangial cells: relevance to diabetic nephropathy. Am J Physiol Renal Physiol 2012; 303:F1145-50. [PMID: 22874765 DOI: 10.1152/ajprenal.00319.2012] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Diabetes is a proinflammatory state. The pattern recognition receptors, Toll-like receptors (TLRs), are increased in diabetic patients and have been suggested to play a role in diabetic nephropathy (DN). Progression of DN involves altered mesangial cell (MC) function with an expansion of the mesangial matrix. There is a paucity of data examining the role of TLR and its expression in MC. We hypothesize the expression of TLRs in the mesangium might be an important factor contributing to mesangium expansion and nephropathy. Thus we evaluated the effect of high glucose on TLR2 and TLR4 expression in mouse mesangial cells (MMC) in vitro. Exposure of MMC to 25 mM glucose for 24 h resulted in increased TLR4 mRNA and cell surface receptor expression compared with 5.5 mM glucose (P < 0.05). Interestingly, we were not able to detect expression of TLR2 in MMC. Furthermore, expression of a TLR4 downstream signaling cascade including myeloid differentiation factor 88 (MyD88), interferon regulatory factor 3 (IRF3), and Toll interleukin receptor domain containing adaptor inducing interferon-β (TRIF)-related adaptor molecule (TRAM) were significantly increased in cells exposed to 25 mM glucose (P < 0.05). There was also a significant increase in NF-κB activation along with increased secretion of inflammatory cytokines IL-6 and monocyte chemotactic protein-1. Levels of transforming growth factor-β were also significantly increased in the presence of 25 mM glucose (P < 0.05). Collectively, these data suggest that hyperglycemia activates TLR4 expression and activity in MC and could contribute to DN.
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Affiliation(s)
- Harmeet Kaur
- Laboratory for Atherosclerosis and Metabolic Research, Department of Pathology and Laboratory Medicine, Universityof California-Sacramento, 4635 Second Ave., Sacramento, CA 95817, USA
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21
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Jialal I, Huet BA, Kaur H, Chien A, Devaraj S. Increased toll-like receptor activity in patients with metabolic syndrome. Diabetes Care 2012; 35:900-4. [PMID: 22357188 PMCID: PMC3308307 DOI: 10.2337/dc11-2375] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The metabolic syndrome (MetS) is highly prevalent and confers an increased risk for diabetes and cardiovascular disease (CVD). While MetS is a proinflammatory state, there is a paucity of data on cellular inflammation in MetS. Toll-like receptors (TLRs) are classical pattern recognition receptors of the innate immune response. RESEARCH DESIGN AND METHODS The aim of this study was to examine monocyte TLR2 and TLR4 in MetS patients without diabetes or CVD and control subjects since both of the receptors have been implicated in atherosclerosis and insulin resistance. Fasting blood was obtained for TLR expression and activity. RESULTS Circulating levels of high-sensitivity C-reactive protein, interleukin (IL)-1β, IL-6, IL-8, and soluble tumor necrosis factor receptor 1 (sTNFR1) were significantly increased in MetS versus control subjects following adjustment for waist circumference. There was a significant increase in both TLR2 and TLR4 surface expression and mRNA on monocytes after adjustment for waist circumference. In addition to increased nuclear factor-κB nuclear binding, there was significantly increased release of IL-1β, IL-6, and IL-8 in MetS versus control subjects following priming of the monocytes with lipopolysaccharides. While both plasma free fatty acids and endotoxin were increased in MetS, they correlated significantly with TLR4 only. CONCLUSIONS In conclusion, we make the novel observation that both TLR2 and TLR4 expression and activity are increased in the monocytes of patients with MetS and could contribute to increased risk for diabetes and CVD.
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Affiliation(s)
- Ishwarlal Jialal
- Laboratory of Atherosclerosis and Metabolic Research, University of California Davis Medical Center, Sacramento, California, USA.
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22
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Jialal I, Kaur H. The Role of Toll-Like Receptors in Diabetes-Induced Inflammation: Implications for Vascular Complications. Curr Diab Rep 2012; 12:172-179. [PMID: 22314791 DOI: 10.1007/s11892-012-0258-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Diabetes confers an increased risk for both microvascular and macrovascular complications. Numerous studies have reported increased levels of biomarkers of inflammation that could predispose to vascular complications. The pattern recognition receptors of the innate immune response, such as Toll-like receptors (TLRs), especially TLR2 and TLR4, have been incriminated in both atherosclerosis and insulin resistance. Studies have reported increased expression and activity of these receptors in both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus. Most recently, knockout of TLR2 has been shown to attenuate the proinflammatory state of T1DM and the progression of diabetic nephropathy. The increased activity of TLRs in diabetes could be the result of a conspiracy of both endogenous and exogenous ligands. Biomediators of increased TLR2 and TLR4 activity include tumor necrosis factor-α, interleukin (IL)-1β, IL-6, monocyte chemoattractant protein-1, and type 1 interferons. Modulating these TLRs could be beneficial in forestalling diabetic complications given the pivotal role of inflammation in both microvascular and macrovascular complications.
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Affiliation(s)
- Ishwarlal Jialal
- Laboratory of Atherosclerosis and Metabolic Research, UC Davis Medical Center, Sacramento, CA, 95817, USA,
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23
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Bertocchi C, Traunwieser M, Dörler J, Hasslacher J, Joannidis M, Dunzendorfer S. Atorvastatin inhibits functional expression of proatherogenic TLR2 in arterial endothelial cells. Cell Physiol Biochem 2011; 28:625-30. [PMID: 22178874 DOI: 10.1159/000335758] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2011] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND There is growing evidence that TLR2 plays a role in the pathogenesis of atherosclerosis. It is highly expressed in endothelial cells in areas of disturbed blood flow, like plaques or vessel bifurcations, but laminar blood flow suppresses endothelial TLR2 expression and is therefore thought to be atheroprotective. We sought for means to also protect lesion prone sites from TLR2 over-expression and subsequent endothelial activation. METHODS Human coronary artery endothelial cells (HCAEC) were treated with atorvastatin (ATV) and TLR2 surface expression was determined by FACS analyses. Western blot analyses were used to explore the phosphorylation status of SP1. RESULTS ATV profoundly inhibited basal and stimulated endothelial TLR2 expression in a time- and dose-dependent manner. It also inhibited HCAEC activation by MALP-2. TLR2 surface expression was inversely correlated to SP1 serine phosphorylation and was casein kinase 2 dependent. CONCLUSION We demonstrate that ATV can control over-expression of proinflammatory endothelial TLR2 protein and TLR2-mediated endothelial activation. The mechanism involves casein kinase 2 and SP1 phosphorylation. ATV effects on endothelial cell TLR2 are comparable to those of laminar blood flow and might therefore also be atheroprotective.
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Affiliation(s)
- Cristina Bertocchi
- Department of Internal Medicine, Medical University of Innsbruck, Anichstrasse 35, Innsbruck, Austria
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24
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Amir J, Waite M, Tobler J, Catalfamo DL, Koutouzis T, Katz J, Wallet SM. The role of hyperglycemia in mechanisms of exacerbated inflammatory responses within the oral cavity. Cell Immunol 2011; 272:45-52. [PMID: 21996642 DOI: 10.1016/j.cellimm.2011.09.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 08/11/2011] [Accepted: 09/19/2011] [Indexed: 02/06/2023]
Abstract
Immune modulating factors are necessary for pathogen clearance, but also contribute to host tissues damage, as those seen in periodontal diseases. Many of these responses can be exacerbated by host conditions including type 2 diabetes [T2D], where toll-like receptor 4 [TLR4] and the receptor for advanced glycated end products [RAGE] play a significant role. Here we investigate causality associated with the increase in inflammatory markers observed in periodontally diseased patients with T2D using multi-variant correlation analysis. Inflammation associated with periodontal diseases, characterized by elevated pro-inflammatory cytokines, innate immune receptor expression, and cellular infiltrate was exacerbated in patients with T2D. In addition, a feed forward loop regulated by poor glycemic control was associated with a loss of mucosal barrier integrity and accumulation of innate immune receptor ligands resulting in an exacerbation of ongoing inflammation, where RAGE and TLR4 cooperated to induce responses in oral epithelial cells, which were exacerbated by hyperglycemia.
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Affiliation(s)
- Jamie Amir
- Department of Periodontology, University of Florida, College of Dentistry, Gainesville, FL 32610, USA.
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25
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Galluzzo S, Patti G, Dicuonzo G, Di Sciascio G, Tonini G, Ferraro E, Spoto C, Campanale R, Zoccoli A, Angeletti S. Association between NOD2/CARD15 polymorphisms and coronary artery disease: a case–control study. Hum Immunol 2011; 72:636-40. [DOI: 10.1016/j.humimm.2011.04.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 04/05/2011] [Accepted: 04/18/2011] [Indexed: 10/18/2022]
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26
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Devaraj S, Tobias P, Jialal I. Knockout of toll-like receptor-4 attenuates the pro-inflammatory state of diabetes. Cytokine 2011; 55:441-5. [PMID: 21498084 DOI: 10.1016/j.cyto.2011.03.023] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 03/18/2011] [Accepted: 03/23/2011] [Indexed: 01/09/2023]
Abstract
Type 1 diabetes (T1DM) is associated with increased vascular complications and is a pro-inflammatory state. Recent findings have shown increased TLR2 and 4 expression, signaling, ligands, and functional activation in T1DM subjects compared to controls and further accentuated in T1DM with microvascular complications. Thus, the aim of this study was to examine if genetic deficiency of TLR4 attenuates the increased inflammation associated with T1DM using the streptozotocin-induced diabetic mouse model. C57BL/6 and TLR4(-/-) mice were obtained and studied in the native state and following induction of diabetes using streptozotocin. Diabetic (WT+STZ) mice had increased expression of both TLR2 and TLR4, while TLR4(-/-) STZ mice had increased expression only of TLR2, but not TLR4 compared to the non-diabetic mice TLR2 expression was significantly increased with STZ-induced diabetes and was unaffected by knockout of TLR4. Also, levels of MyD88, IRAK-1 protein phosphorylation, Trif, IRF3, and NF-κB activity were significantly reduced in TLR4(-/-) +STZ mice compared to the WT+STZ mice. WT+STZ mice exhibited significantly increased levels of serum and macrophage IL-1β, IL-6, KC/IL-8, IP-10, MCP-1, IFN beta and TNF-α compared to WT mice and this was significantly attenuated in TLR4(-/-) +STZ mice (P<0.01). Thus, TLR4 contributes to the pro-inflammatory state and TLR4KO attenuates inflammation in diabetes.
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Affiliation(s)
- Sridevi Devaraj
- Laboratory for Atherosclerosis and Metabolic Research, University of California, Davis, Medical Center, Sacramento CA, USA
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27
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Karper JC, de Vries MR, van den Brand BT, Hoefer IE, Fischer JW, Jukema JW, Niessen HWM, Quax PHA. Toll-like receptor 4 is involved in human and mouse vein graft remodeling, and local gene silencing reduces vein graft disease in hypercholesterolemic APOE*3Leiden mice. Arterioscler Thromb Vasc Biol 2011; 31:1033-40. [PMID: 21330606 DOI: 10.1161/atvbaha.111.223271] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE The goal of this study was to explore the role of Toll-like receptor 4 (TLR4) in vein graft remodeling and disease. METHODS AND RESULTS First, expression of TLR4 was analyzed in freshly isolated human saphenous veins (huSV), in freshly isolated huSV ex vivo perfused in an extracorporeal circulation, or in huSV used as coronary vein grafts. Marked induction of focal TLR4 expression was observed in perfused fresh huSV. Moreover, TLR4 was abundantly present in lesions in fresh huSV or in intimal hyperplasia in coronary vein grafts. Second, mouse venous bypass grafting was performed. In grafts of hypercholesterolemic APOE*3Leiden mice, increased TLR4 mRNA and protein was detected over time by reverse transcription-polymerase chain reaction and immunohistochemistry. Furthermore, the local presence of the endogenous TLR4 ligands heat shock protein 60, high-mobility group box 1, tenascin-C, and biglycan in the grafts was demonstrated. TLR4 deficiency in C3H-Tlr4LPS-d (LPS indicates lipopolysaccharide) mice resulted in 48±12% less vein graft wall thickening (P=0.04) than in Balb/c controls. Moreover, local TLR4 gene silencing in hypercholesterolemic APOE*3Leiden mice using lentiviral short hairpin RNA against TLR4 administered perivascularly around vein grafts led to a 44±13% reduction of vessel wall thickening compared with controls (P=0.0059). CONCLUSIONS These results indicate that TLR4 is involved in vein graft remodeling and can be used as a local therapeutic target against vein graft disease.
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Affiliation(s)
- Jacco C Karper
- Department of Vascular Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, the Netherlands
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28
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Devaraj S, Jialal I, Yun JM, Bremer A. Demonstration of increased toll-like receptor 2 and toll-like receptor 4 expression in monocytes of type 1 diabetes mellitus patients with microvascular complications. Metabolism 2011; 60:256-9. [PMID: 20153491 PMCID: PMC2891423 DOI: 10.1016/j.metabol.2010.01.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 12/29/2009] [Accepted: 01/08/2010] [Indexed: 12/19/2022]
Abstract
Type 1 diabetes mellitus (T1DM) is associated with increased microvascular complications and is a proinflammatory state. The toll-like receptors (TLRs) are pattern recognition receptors on monocytes and important in atherosclerosis. We have shown increased TLR2 and TLR4 expression on monocytes of T1DM compared with controls. In this report, we tested the surface expression of TLR2 and TLR4 on monocytes of T1DM patients with microvascular complications (T1DM-MV) compared with those without (T1DM) and healthy controls. The study was performed at the University of California Davis. Healthy controls (n = 31), T1DM patients (n = 31), and T1DM-MV patients (n = 34) were included. The TLR2 and TLR4 surface expression was significantly increased in T1DM-MV monocytes compared with T1DM and controls (P < .01). In addition, nuclear factor κB activity and interleukin-1β release were significantly increased in monocytes from T1DM-MV compared with T1DM (P < .005). Thus, we make the novel observation that TLR2 and TLR4 expression and signaling are increased in T1DM-MV compared with T1DM and may contribute to the accentuated proinflammatory state and complications of T1DM.
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Affiliation(s)
- Sridevi Devaraj
- Laboratory for Atherosclerosis and Metabolic Research, University of California, Davis, Medical Center, Sacramento, CA 95817, USA.
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29
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Faulin TDES, Cavalcante MF, Abdalla DSP. Role of electronegative LDL and its associated antibodies in the pathogenesis of atherosclerosis. ACTA ACUST UNITED AC 2010. [DOI: 10.2217/clp.10.52] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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30
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Arranz L, De Castro NM, Baeza I, Maté I, Viveros MP, De la Fuente M. Environmental Enrichment Improves Age-Related Immune System Impairment: Long-Term Exposure Since Adulthood Increases Life Span in Mice. Rejuvenation Res 2010; 13:415-28. [DOI: 10.1089/rej.2009.0989] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Lorena Arranz
- Department of Physiology (Animal Physiology II), Faculty of Biological Sciences, Madrid Complutense University, Madrid, Spain
| | - Nuria M. De Castro
- Department of Physiology (Animal Physiology II), Faculty of Biological Sciences, Madrid Complutense University, Madrid, Spain
| | - Isabel Baeza
- Department of Physiology (Animal Physiology II), Faculty of Biological Sciences, Madrid Complutense University, Madrid, Spain
| | - Ianire Maté
- Department of Physiology (Animal Physiology II), Faculty of Biological Sciences, Madrid Complutense University, Madrid, Spain
| | - Maria Paz Viveros
- Department of Physiology (Animal Physiology II), Faculty of Biological Sciences, Madrid Complutense University, Madrid, Spain
| | - Mónica De la Fuente
- Department of Physiology (Animal Physiology II), Faculty of Biological Sciences, Madrid Complutense University, Madrid, Spain
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Lubos E, Mahoney CE, Leopold JA, Zhang YY, Loscalzo J, Handy DE. Glutathione peroxidase-1 modulates lipopolysaccharide-induced adhesion molecule expression in endothelial cells by altering CD14 expression. FASEB J 2010; 24:2525-32. [PMID: 20219985 PMCID: PMC2887263 DOI: 10.1096/fj.09-147421] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Accepted: 02/12/2010] [Indexed: 12/14/2022]
Abstract
CD14 contributes to LPS signaling in leukocytes through formation of toll-like receptor 4/CD14 receptor complexes; however, a specific role for endogenous cell-surface CD14 in endothelial cells is unclear. We have found that suppression of glutathione peroxidase-1 (GPx-1) in human microvascular endothelial cells increases CD14 gene expression compared to untreated or siControl (siCtrl)-treated conditions. Following LPS treatment, GPx-1 deficiency augmented LPS-induced intracellular reactive oxygen species accumulation, CD14 expression, and intercellular adhesion molecule-1 (ICAM-1) mRNA and protein expression compared to LPS-treated control cells. GPx-1 deficiency also transiently augmented LPS-induced vascular cell adhesion molecule-1 (VCAM-1) expression. Adenoviral overexpression of GPx-1 significantly diminished LPS-mediated responses in adhesion molecule expression. Consistent with these findings, LPS responses were also greater in endothelial cells derived from GPx-1-knockout mice, whereas adhesion molecule expression was decreased in cells from GPx-1-overexpressing transgenic mice. Knockdown of CD14 attenuated LPS-mediated up-regulation of ICAM-1 and VCAM-1 mRNA and protein, and it mitigated the effects of GPx-1 deficiency on LPS-induced adhesion molecule expression. Taken together, these data suggest that GPx-1 modulates the endothelial cell response to LPS, in part, by altering CD14-mediated effects.
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Affiliation(s)
- Edith Lubos
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, 77 Ave. Louis Pasteur, Boston, MA 02115, USA
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Heo SK, Yi HS, Yun HJ, Ko CH, Choi JW, Park SD. Ethylacetate extract from Draconis Resina inhibits LPS-induced inflammatory responses in vascular smooth muscle cells and macrophages via suppression of ROS production. Food Chem Toxicol 2010; 48:1129-36. [DOI: 10.1016/j.fct.2009.06.043] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 06/24/2009] [Accepted: 06/26/2009] [Indexed: 01/04/2023]
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Differential expression of Toll-like receptor 2 and 4 on peritoneal leukocyte populations from long-lived and non-selected old female mice. Biogerontology 2010; 11:475-82. [DOI: 10.1007/s10522-010-9270-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 03/08/2010] [Indexed: 10/19/2022]
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Effect of Inhibition of Toll-like Receptor 4 on The Development of Atherosclerosis in Apolipoprotein E Knockout (apoE<SUP>-/-</SUP>) Mice*. PROG BIOCHEM BIOPHYS 2010. [DOI: 10.3724/sp.j.1206.2009.00118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Devaraj S, Dasu MR, Jialal I. Diabetes is a proinflammatory state: a translational perspective. Expert Rev Endocrinol Metab 2010; 5:19-28. [PMID: 20204165 PMCID: PMC2829992 DOI: 10.1586/eem.09.44] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The diabetic state confers an increased propensity to accelerated atherogenesis. Inflammation is pivotal in atherosclerosis; in addition to the established risk factors, inflammation appears to play a pivotal role in diabetes and its complications. Evidence for increased inflammation includes: increased levels of plasma C-reactive protein, the prototypic marker of inflammation; increased levels of plasminogen-activator inhibitor; increased monocyte superoxide and proinflammatory cytokine release (IL-1, IL-6 and TNF-alpha); increased monocyte adhesion to endothelium; increased NF-kappaB activity; and increased Toll-like receptor 2 and 4 expression and activity in diabetes. Thus, it appears that both Type 1 and Type 2 diabetes are proinflammatory states and that these could contribute to increased diabetic vasculopathies.
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Affiliation(s)
- Sridevi Devaraj
- Laboratory for Atherosclerosis and Metabolic Research, Department of Pathology, UC Davis Medical Center, Research One Building, 4635 Second Avenue Room 3000, Sacramento, CA 95817, USA
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Portugal LR, Fernandes LR, Alvarez-Leite JI. Host cholesterol and inflammation as common key regulators of toxoplasmosis and artherosclerosis development. Expert Rev Anti Infect Ther 2009; 7:807-19. [PMID: 19735223 DOI: 10.1586/eri.09.60] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Atherosclerosis and toxoplasmosis are two widely prevalent diseases worldwide. The relationship between these diseases is now being elucidated. Atherosclerosis is a disease with three main components: increased blood lipoprotein/cholesterol and their deposition in the arterial wall, an important Th1-mediated proinflammatory reaction and thrombogenic status. Toxoplasma gondii, in turn, is dependent on host cholesterol for optimal intracellular growth and replication. As a result, host cholesterol will be cleared from the blood, reducing plasma low-density lipoprotein, a crucial atherosclerosis risk factor. On the other hand, T. gondii infection elicits an important Th1 systemic inflammatory response in the host. Therefore, this additional proinflammatory stimulus may impose an enhanced pro-atherogenic environment in the host. As result, the association between these two diseases in one individual could change the course of atherosclerosis. In this review, we demonstrate that the host-parasite relationship is complex and that the outcome of each disease is dependent on the availability of intracellular cholesterol, as well as the intensity of the inflammatory reaction triggered by the parasite. We also discuss the possible clinical implications of these studies.
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Effects of chronic mild stress on the development of atherosclerosis and expression of toll-like receptor 4 signaling pathway in adolescent apolipoprotein E knockout mice. J Biomed Biotechnol 2009; 2009:613879. [PMID: 19746160 PMCID: PMC2734999 DOI: 10.1155/2009/613879] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 06/09/2009] [Accepted: 06/10/2009] [Indexed: 12/30/2022] Open
Abstract
Here, we investigated the effect of chronic mild stress (CMS) on the development of atherosclerosis as well as the expression of Toll-like receptors (TLRs) signaling pathway in adolescent apolipoprotein E knockout (apoE-/-) mice. Mice were subjected to daily CMS for 0, 4, and 12 weeks, respectively. To identify the expression of Toll-like receptor 4 signaling pathway in adolescent apolipoprotein E knockout mice subjected to CMS, we compared gene expression in aortas of stressed and unstressed mice using TLRs signaling pathway real-time PCR microarrays consisting of 87 genes. We found that atherosclerosis lesions both in aortic tress and sinuses of CMS mice were significantly increased linearly in response to duration of CMS exposure. Among 87 genes analyzed, 15 genes were upregulated in stressed mice, especially TLR4, myeloid differentiation factor 88 (MyD88), and IL-1β, and 28 genes were downregulated compared with nonstressed mice. CMS mice demonstrated markedly increased aortic atherosclerosis that were associated with significant increases in levels of expression of TLR4, MyD88, nuclear factor κB (NF-κB), MCP-1, IL-1β, TNF-α, and sICAM-1. Taken together, our results suggest an important role for TLR4 signaling pathway in atherosclerosis in a CMS mouse model.
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Anti-inflammatory action of apoptotic cells in patients with acute coronary syndromes. Atherosclerosis 2009; 205:391-5. [DOI: 10.1016/j.atherosclerosis.2008.12.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 12/27/2008] [Accepted: 12/28/2008] [Indexed: 01/04/2023]
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Dasu MR, Park S, Devaraj S, Jialal I. Pioglitazone inhibits Toll-like receptor expression and activity in human monocytes and db/db mice. Endocrinology 2009; 150:3457-64. [PMID: 19389833 PMCID: PMC2717888 DOI: 10.1210/en.2008-1757] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 04/10/2009] [Indexed: 12/11/2022]
Abstract
Toll-like receptors (TLRs) are key innate immune sensors of endogenous damage signals and play an important role in inflammatory diseases like diabetes and atherosclerosis. Pioglitazone (PIO), a peroxisome proliferator-activated receptor (PPAR)-gamma agonist, has been reported to be an antiinflammatory agent. Thus, in the present study, we examined the antiinflammatory effects of PIO on TLR2 and TLR4 expression in human monocytes exposed to Pam3CSK4 (Pam; TLR2 ligand) and purified lipopolysaccharide (LPS; TLR4 ligand) using flow cytometry and real-time RT-PCR. Monocytes were isolated from healthy human volunteers and pretreated with PIO (1 microM) followed by Pam (170 ng/ml) and LPS (160 ng/ml) challenge. PIO significantly decreased Pam- and LPS-induced TLR2 (-56%) and TLR4 (-78%) expression (P < 0.05). In addition, PIO decreased TLR ligand-induced nuclear factor-kappaB activity (-63%), IL-1beta (-50%), IL-6 (-52%), monocyte chemoattractant protein-1(-83%), and TNF-alpha (-87%) compared with control. Next, PIO-treated db/db mice (n = 6/group) showed decreased TLR2 (-60%) and TLR4 (-45%) expression in peritoneal macrophages compared with vehicle control mice (P < 0.001) with associated decrease in MyD88-dependent signaling and nuclear factor-kappaB activation. Data suggest that Pam- and LPS-induced TLR2 and TLR4 expression are inhibited by PIO in human monocytes and db/db mice. Thus, we define a novel pathway by which PIO could induce antiinflammatory effects.
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Affiliation(s)
- Mohan R Dasu
- Laboratory for Atherosclerosis and Metabolic Research, University of California, Davis, Medical Center, Sacramento, California 95817, USA.
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Devaraj S, Dasu MR, Park SH, Jialal I. Increased levels of ligands of Toll-like receptors 2 and 4 in type 1 diabetes. Diabetologia 2009; 52:1665-8. [PMID: 19455302 PMCID: PMC2709882 DOI: 10.1007/s00125-009-1394-8] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Accepted: 04/24/2009] [Indexed: 12/22/2022]
Abstract
AIMS/HYPOTHESIS Type 1 diabetes is a proinflammatory state characterised by increased levels of circulating biomarkers of inflammation and monocyte activity. We have shown increased Toll-like receptor 2 (TLR2) and TLR4 expression and signalling in monocytes from type 1 diabetic patients. Several endogenous ligands of TLR2 and TLR4 have been identified; however, there is a paucity of data on levels of these endogenous ligands in diabetes. Thus, the aim of this study was to examine circulating levels of exogenous/endogenous ligands of TLR2 and TLR4 in type 1 diabetic patients and to compare these with the levels in matched healthy controls. METHODS Healthy controls (n = 37) and type 1 diabetic patients (n = 34) were recruited, and a fasting blood sample was obtained. Circulating levels of endotoxin, heat-shock protein 60 (Hsp60), high-mobility group box 1 (HMGB1) and growth arrest-specific 6 (GAS6) proteins were assessed by ELISA, and TLR2 and TLR4 expression was determined by flow cytometry. RESULTS Levels of the classical TLR4 ligand, endotoxin, were significantly elevated in type 1 diabetic patients compared with those in matched controls. Hsp60 and HMGB1 concentrations were also significantly increased in the patients (p < 0.01 and p < 0.001, respectively). No significant differences were observed in GAS6. CONCLUSIONS/INTERPRETATION We report the novel observation that levels of ligands of TLR2 and TLR4 are significantly elevated in type 1 diabetes, and this, in concert with hyperglycaemia, accounts for the increase in TLR2 and TLR4 activity, underscoring the proinflammatory state of type 1 diabetes.
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Affiliation(s)
- S. Devaraj
- Laboratory for Atherosclerosis and Metabolic Research, UC Davis Medical Center, 4635 II Ave, Res. 1 Bldg, Rm 3000, Sacramento, CA 95817 USA
- VA Medical Center, Mather, CA USA
| | - M. R. Dasu
- Laboratory for Atherosclerosis and Metabolic Research, UC Davis Medical Center, 4635 II Ave, Res. 1 Bldg, Rm 3000, Sacramento, CA 95817 USA
| | - S. H. Park
- Laboratory for Atherosclerosis and Metabolic Research, UC Davis Medical Center, 4635 II Ave, Res. 1 Bldg, Rm 3000, Sacramento, CA 95817 USA
| | - I. Jialal
- Laboratory for Atherosclerosis and Metabolic Research, UC Davis Medical Center, 4635 II Ave, Res. 1 Bldg, Rm 3000, Sacramento, CA 95817 USA
- VA Medical Center, Mather, CA USA
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Alegre ML, Chong A. Toll-like receptors (TLRs) in transplantation. Front Biosci (Elite Ed) 2009; 1:36-43. [PMID: 19482622 DOI: 10.2741/e4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
TLRs have been extensively studied over the past decade for their ability to recognize microbial molecular patterns and activate innate immune cells to fight infections. They have also been described to provide a link between innate and adaptive immunity, as TLR signals also enhance the antigen presenting capacity of innate immune cells to T cells. In recent years, a contribution of TLR pathways to immune responses elicited by ischemia/reperfusion injury (IRI), allografts and xenografts has been uncovered, although the ligands that bind TLRs in these settings remain to be revealed. Such research has the potential to identify novel therapeutic targets that may facilitate allograft acceptance. In this review, we will summarize the results published to date on the role of TLRs in experimental and clinical transplantation.
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Affiliation(s)
- Maria-Luisa Alegre
- Department of Medicine, The University of Chicago, 5841 S. Maryland Avenue, Chicago, IL60637, USA.
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Balistreri CR, Colonna-Romano G, Lio D, Candore G, Caruso C. TLR4 polymorphisms and ageing: implications for the pathophysiology of age-related diseases. J Clin Immunol 2009; 29:406-15. [PMID: 19459036 DOI: 10.1007/s10875-009-9297-5] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Accepted: 04/15/2009] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Innate immunity provides a first line of host defense against infection by recognizing and killing microbes while simultaneously activating an instructive immune response. Toll-like receptors (TLRs) are principal mediators of rapid microbial recognition and function mainly by detection of pathogen-associated molecular patterns that do not exist in the host. Recognition of their ligands leads to a series of signaling events resulting in acute host responses, involved in killing pathogens. DISCUSSION We describe the involvement of TLR4 polymorphisms in ageing, and in particular in age-related diseases, suggesting the crucial role of molecules of innate immunity in pathophysiology of these diseases. Hence, we observed that pro-inflammatory alleles may be related to unsuccessful ageing, such as Alzheimer's disease, prostate cancer, and atherosclerosis; in contrast, the control of inflammation by anti-inflammatory alleles may result in increased longevity and successful ageing. Finally, a possible therapeutic approach to delay age-related diseases is outlined.
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Affiliation(s)
- Carmela Rita Balistreri
- Gruppo di Studio sull'Immunosenescenza, Dipartimento di Biopatologia e Metodologie Biomediche dell'Università di Palermo, Corso Tukory, Palermo, Italy.
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Devaraj S, Jialal I. Increased secretion of IP-10 from monocytes under hyperglycemia is via the TLR2 and TLR4 pathway. Cytokine 2009; 47:6-10. [PMID: 19447045 DOI: 10.1016/j.cyto.2009.02.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Revised: 01/28/2009] [Accepted: 02/12/2009] [Indexed: 12/18/2022]
Abstract
Among the chemokines, members of the CXC family include IP-10 (interferon-gamma induced protein of 10kDa). Elevated serum IP-10 levels have been shown in diabetes. However, there is a paucity of data examining the sources and regulation of IP-10 under hyperglycemic conditions and this was the overall aim of the study. Type 1 diabetes (T1DM) is a pro-inflammatory state. We previously demonstrated increased toll like receptor (TLR) 2 and 4 activation in monocytes of T1DM patients. Thus, we also examined the role of the TLR pathway in modulating IP-10 release from human monocytes under hyperglycemia. Also, circulating and monocytic levels of IP-10 in patients with T1DM with and without microvascular complications (T1DM-MV and T1DM) and controls (C) was assessed. Under HG, IP-10 mRNA and protein were significantly increased compared to normoglycemia. Incubation of monocytes with dominant negative Ikb but not control vector significantly abrogated HG-induced IP-10 release. Furthermore, both TLR2 siRNA as well as TLR4 siRNA, either alone or in combination significantly abrogated HG-induced IP-10 release. Serum and monocytic levels of IP-10 were significantly increased in T1DM and T1DM-MV compared to matched controls. Thus, we demonstrate increased circulating and monocytic IP-10 in T1DM. Down-regulation of TLR2 and TLR4 abrogates HG-induced IP-10 release via NF-kappaB inhibition.
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Affiliation(s)
- Sridevi Devaraj
- Department of Medical Pathology and Laboratory Medicine, Laboratory for Atherosclerosis and Metabolic Research, Robert E.Stowell Endowed Chair in Experimental Pathology, UC Davis Medical Center, Sacramento, CA 95817, USA
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Alvarez Y, Municio C, Alonso S, Román JAS, Crespo MS, Fernández N. Cyclooxygenase-2 Induced by Zymosan in Human Monocyte-Derived Dendritic Cells Shows High Stability, and Its Expression Is Enhanced by Atorvastatin. J Pharmacol Exp Ther 2009; 329:987-94. [DOI: 10.1124/jpet.108.149336] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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Identification of potential pathway mediation targets in Toll-like receptor signaling. PLoS Comput Biol 2009; 5:e1000292. [PMID: 19229310 PMCID: PMC2634968 DOI: 10.1371/journal.pcbi.1000292] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Accepted: 01/07/2009] [Indexed: 01/01/2023] Open
Abstract
Recent advances in reconstruction and analytical methods for signaling networks have spurred the development of large-scale models that incorporate fully functional and biologically relevant features. An extended reconstruction of the human Toll-like receptor signaling network is presented herein. This reconstruction contains an extensive complement of kinases, phosphatases, and other associated proteins that mediate the signaling cascade along with a delineation of their associated chemical reactions. A computational framework based on the methods of large-scale convex analysis was developed and applied to this network to characterize input–output relationships. The input–output relationships enabled significant modularization of the network into ten pathways. The analysis identified potential candidates for inhibitory mediation of TLR signaling with respect to their specificity and potency. Subsequently, we were able to identify eight novel inhibition targets through constraint-based modeling methods. The results of this study are expected to yield meaningful avenues for further research in the task of mediating the Toll-like receptor signaling network and its effects. The human innate immune system, as the first line of defense against pathogens, is a vital component of our survival. One component of the innate immune system is the Toll-like receptor signaling network, which is responsible for transmitting activation signals from the outside of the cell to molecular machinery inside the cell. The innate immune system must be properly balanced, as excessive activation can lead to potentially lethal septic shock. Therefore, there is much interest in developing drugs that can mediate Toll-like receptor signaling so as to alleviate effects of excess activation. We present an in silico reconstruction of the Toll-like receptor signaling network and convert it into a mathematical framework that is suitable for constraint-based modeling and analysis. This approach leads to the identification of potential candidates for drug-based mediation. In addition to identifying targets for drug mediation of the Toll-like receptor network, we also supply a network model that may be continually updated and maintained.
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Nogueira-Machado JA, Chaves MM. From hyperglycemia to AGE-RAGE interaction on the cell surface: a dangerous metabolic route for diabetic patients. Expert Opin Ther Targets 2008; 12:871-82. [PMID: 18554155 DOI: 10.1517/14728222.12.7.871] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
BACKGROUND Diabetes mellitus constitutes a serious public health problem. Recent advances in therapies are unable to control its vascular complications. New medications have been suggested but without comprehensive knowledge of the signaling pathways induced by hyperglycemia. OBJECTIVE To review the mechanisms of the inducer and effector phases of the metabolic cascade in diabetes, with emphasis on the steps that have been targeted to date The route from hyperglycemia to advanced glycation end products (AGE)-receptor of advanced glycation end products (RAGE) complex formation is suggested as a target for new therapies. METHODS A review of literature, including historical papers and recent manuscripts. RESULTS All the components of the suggested route are initially activated or indirectly formed due to hyperglycemia via a two-phase cascade that represents a dangerous metabolic route, especially for diabetics. Recent experiments with new drugs and clinical trials targeting this pathway are examined. CONCLUSIONS In order to control vascular injury in diabetes, several steps in the cascade need to be inhibited simultaneously together with aggressive glycemic control.
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Affiliation(s)
- José Augusto Nogueira-Machado
- Hospital Santa Casa de Belo Horizonte, Núcleo de Pesquisa e Pós-Graduação, Avenue Francisco Sales, 1111, 30250-330, Belo Horizonte, MG, Brazil.
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Gomez CR, Nomellini V, Faunce DE, Kovacs EJ. Innate immunity and aging. Exp Gerontol 2008; 43:718-28. [PMID: 18586079 DOI: 10.1016/j.exger.2008.05.016] [Citation(s) in RCA: 189] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 05/27/2008] [Accepted: 05/30/2008] [Indexed: 12/16/2022]
Abstract
Advanced age is associated with defects in all of the cells of the innate immune system, including numbers, function, and early stages of activation. This review, presents the current state of the field on the impact of age on the innate immune system. The analysis of the literature suggests that a dysfunctional innate immune system is a contributing factor to aberrant outcomes after injury or infection and to the development of many of the diseases observed in the elderly. Gaining an understanding of the nature of the defects in innate immune cells may allow the development of therapeutic strategies aimed to restore innate immune function in aged individuals.
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Affiliation(s)
- Christian R Gomez
- The Burn and Shock Trauma Institute, Loyola University Medical Center, Maywood, IL 60153, USA
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Dasu MR, Riosvelasco AC, Jialal I. Candesartan inhibits Toll-like receptor expression and activity both in vitro and in vivo. Atherosclerosis 2008; 202:76-83. [PMID: 18495130 DOI: 10.1016/j.atherosclerosis.2008.04.010] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Revised: 03/25/2008] [Accepted: 04/09/2008] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Toll-like receptors play an important role in the innate immune system and are found to be crucial in severe diseases like sepsis, atherosclerosis, and arthritis. TLR2 and TLR4 expression is upregulated in the inflammatory diseases. Angiotensin II in addition to stimulating vasoconstriction also induces an increase in ROS and a proinflammatory phenotype via AT(1)R. Angiotensin II type-1 receptor blocker (ARB), widely used as an antihypertensive drug, has been reported to also have anti-inflammatory effects. Thus, we investigated whether an ARB exerts anti-inflammatory effects via inhibiting TLR2 and TLR4 expression. METHODS AND RESULTS Monocytes were isolated from healthy human volunteers and treated with the synthetic lipoprotein Pam3CSK4 or LPS in the absence or presence of candesartan. Pretreatment of human monocytes with candesartan significantly decreased Pam3CSK4 or LPS induced TLR2 and TLR4 expression of both mRNA and protein levels (P<0.05 vs. control) along with decrease in the activity of NF-kappaB and the expression of IL-1beta, IL-6, TNF-alpha, and MCP-1. Furthermore, candesartan treated mice show decreased TLR2 and TLR4 expression compared to vehicle control mice. CONCLUSION Pam3CSK4 and LPS induced TLR2 and TLR4 expression at mRNA and protein levels are inhibited by candesartan both in vitro and in vivo. Thus, we define a novel pathway by which candesartan could induce anti-inflammatory effects.
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Affiliation(s)
- Mohan R Dasu
- Laboratory for Atherosclerosis and Metabolic Research, University of California Davis Medical Center, Sacramento, CA 95817, United States
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Role of pattern-recognition receptors in cardiovascular health and disease. Biochem Soc Trans 2008; 35:1449-52. [PMID: 18031243 DOI: 10.1042/bst0351449] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A role for PRRs (pattern-recognition receptors) in immune cell function is now well established. In macrophages and other immune cells, activation of TLRs (Toll-like receptors) and cytosolic NLRs [NOD (nucleotide oligomerization domain) proteins containing a leucine-rich repeat] results in the induction of genes and release of imunoregulator hormones including cytokines and NO (nitric oxide). In addition to immune cells, structural cells of the cardiovascular system including endothelial cells, vascular smooth muscle and cardiac myocytes express functional PRRs and sense PAMPs (pathogen-associated molecular patterns). Furthermore, bacteria and PAMPs activate the coagulation system and platelets. TLRs are now implicated in a range of cardiovascular diseases and syndromes including atherosclerosis and sepsis. Our group is working on the hypotheses that differences exist in how tissues of the cardiovascular system, including vessels, endothelium, heart and blood, sense pathogens compared with immune cells (principally macrophages) and that identifying such differences will reveal new therapeutic targets for the treatment of cardiovascular disease. We have identified examples of similarities and differences in how cardiovascular tissues and macrophages sense PAMPs. These findings will be discussed together with our interpretation of how this information may lead to new treatments.
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Abstract
At one time, atherosclerosis was thought to be a simple lipid storage disease. However, it is now recognized as a chronic and progressive inflammation of the arterial wall. Gene deletion experiments in murine models of atherosclerosis that reduce the inflammatory process also reduce disease severity. Identifying the initiators and mediators of that inflammation can provide promising avenues for prevention or therapy. Two prominent risk factors, hyperlipidaemia and infectious disease, point to innate immune mechanisms as potential contributors to proatherogenic inflammation. The TLRs (Toll-like receptors), pro-inflammatory sensors of pathogens, are potential links between inflammation, infectious disease and atherosclerosis. A mechanism for hyperlipidaemic initiation of sterile inflammation can be postulated because oxidized lipoproteins or their component oxidized lipids have been identified as TLR ligands. Moreover, infectious agents are correlated with atherosclerosis risk. We have identified a role for TLR2 in atherosclerosis in mice deficient in low-density lipoprotein receptor. We observed that proatherogenic TLR2 responses to unknown endogenous or unknown endemic exogenous agonists are mediated by non-BMDC (bone-marrow-derived cells), which can include endothelial cells. In contrast, the proatherogenic TLR2 responses to the defined synthetic exogenous agonist Pam3 CSK4 are mediated at least in part by BMDC, which can include lymphocytes, monocytes/macrophages and dendritic cells. TLR2-mediated cell activation in response to endogenous and exogenous agents is proatherogenic in hyperlipidaemic mice.
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