scholarly journals The Cooperative Induction of CCL4 in Human Monocytic Cells by TNF-α and Palmitate Requires MyD88 and Involves MAPK/NF-κB Signaling Pathways

2019 ◽  
Vol 20 (18) ◽  
pp. 4658 ◽  
Author(s):  
Sindhu ◽  
Kochumon ◽  
Shenouda ◽  
Wilson ◽  
Al-Mulla ◽  
...  
Keyword(s):  
Low Grade ◽  
Monocytic Cells ◽  
Signaling Mechanism ◽  
Blocking Antibody ◽  
Metabolic Inflammation ◽  
Qrt Pcr ◽  
Signaling Mechanisms ◽  
Tnf Α ◽  
Low Grade Inflammation ◽  
Tlr4 Receptor

: Chronic low-grade inflammation, also known as metabolic inflammation, is a hallmark of obesity and parallels with the presence of elevated circulatory levels of free fatty acids and inflammatory cytokines/chemokines. CCL4/MIP-1β chemokine plays a key role in the adipose tissue monocyte recruitment. Increased circulatory levels of TNF-α, palmitate and CCL4 are co-expressed in obesity. We asked if the TNF-α/palmitate could interact cooperatively to augment the CCL4 production in human monocytic cells and macrophages. THP-1 cells/primary macrophages were co-treated with TNF-α/palmitate and CCL4 mRNA/protein expression was assessed using qRT-PCR/ELISA. TLR4 siRNA, a TLR4 receptor-blocking antibody, XBlue™-defMyD cells and pathway inhibitors were used to decipher the signaling mechanisms. We found that TNF-α/palmitate co-stimulation augmented the CCL4 expression in monocytic cells and macrophages compared to controls (p < 0.05). TLR4 suppression or neutralization abrogated the CCL4 expression in monocytic cells. Notably, CCL4 cooperative induction in monocytic cells was: (1) Markedly less in MyD88-deficient cells, (2) IRF3 independent, (3) clathrin dependent and (4) associated with the signaling mechanism involving ERK1/2, c-Jun, JNK and NF-κB. In conclusion, TNF-α/palmitate co-stimulation promotes the CCL4 expression in human monocytic cells through the mechanism involving a TLR4-MyD88 axis and MAPK/NF-κB pathways. These findings unravel a novel mechanism of the cooperative induction of CCL4 by TNF-α and palmitate which could be relevant to metabolic inflammation.

IL-6 as a Surrogate Biomarker: The IL-6 Clinical Value for the Diagnosis of Insulin Resistance and Type 2 Diabetes.

2021 ◽  
pp. 1-13
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Molecular Mechanisms ◽  
Diagnostic Value ◽  
Low Grade ◽  
Clinical Value ◽  
Insulin Resistant ◽  
Tnf Α ◽  
Low Grade Inflammation

1. Abstract Insulin Resistance is the leading cause of Type 2 diabetes mellitus (T2D). It occurs as a result of lipid disorders and increased levels of circulating free fatty acids (FFAs). FFAs accumulate within the insulin sensitive tissues such as muscle, liver and adipose tissues exacerbating different molecular mechanisms. Increased levels fatty acid has been documented to be strongly associated with insulin resistant states and obesity causing inflammation that eventually causes type 2-diabetes. Among the biomarkers that are accompanying low grade inflammation include IL-1β, IL-6 and TNF-α. The current review point out the importance of measuring the inflammatory biomarkers especially focusing on the conductance and measurement for IL-6 as a screening laboratory test and its diagnostic value in clinical practice.

Betaine reduces the expression of inflammatory adipokines caused by hypoxia in human adipocytes

2012 ◽  
Vol 109 (1) ◽  
pp. 43-49 ◽  
Author(s):  
K. Olli ◽  
S. Lahtinen ◽  
N. Rautonen ◽  
K. Tiihonen
Keyword(s):  
Adipose Tissue ◽  
Inflammatory Markers ◽  
Mrna Level ◽  
Low Grade ◽  
Human Adipocytes ◽  
Low Oxygen ◽  
Hypoxic Conditions ◽  
Tnf Α ◽  
Oxygen Conditions ◽  
Low Grade Inflammation

Obesity is characterised by a state of chronic low-grade inflammation and the elevated circulating and tissue levels of inflammatory markers, including inflammation-related adipokines, released from white adipose tissue. The expression and release of these adipokines generally rises as the adipose tissue expands and hypoxic conditions start to develop within the tissue. Here, the effect of betaine, a trimethylglycine having a biological role as an osmolyte and a methyl donor, on the expression of inflammation-related markers was tested in human adipocytes under hypoxia. Differentiated adipocytes were cultivated under low (1 %) oxygen tension for 8–20 h. The expression of different adipokines, including IL-6, leptin, PPARγ, TNF-α and adiponectin, was measured by quantitative PCR by determining the relative mRNA level from the adipocytes. Hypoxia, in general, led to a decrease in the expression of PPARγ mRNA in human adipocytes, whereas the expression levels of leptin and IL-6 mRNA were substantially increased by hypoxia. The cultivation of adipocytes under hypoxia also led to a reduction in the expression of TNF-α mRNA. The results showed that hypoxia increased the relative quantification of leptin gene transcription, and that betaine (250 μmol/l) reduced this effect, caused by low oxygen conditions. Under hypoxia, betaine also reduced the mRNA level of the pro-inflammatory markers IL-6 and TNF-α. These results demonstrate that the extensive changes in the expression of inflammation-related adipokines in human adipocytes caused by hypoxia can be diminished by the presence of physiologically relevant concentrations of betaine.

scholarly journals The Role of Exercise Training on Low-Grade Systemic Inflammation in Adults with Overweight and Obesity: A Systematic Review

2021 ◽  
Vol 18 (24) ◽  
pp. 13258
Author(s):  
Paola Gonzalo-Encabo ◽  
Gonzalo Maldonado ◽  
David Valadés ◽  
Carmen Ferragut ◽  
Alberto Pérez-López
Keyword(s):  
Exercise Training ◽  
Systemic Inflammation ◽  
Fat Mass ◽  
Overweight And Obesity ◽  
Concurrent Training ◽  
Low Grade ◽  
Mass Reduction ◽  
Tnf Α ◽  
Exercise Induced ◽  
Low Grade Inflammation

Low-grade systemic inflammation leads to critical alterations of several tissues and organs that can promote the appearance of non-communicable diseases, a risk that is increased in adults with obesity. Exercise training may counteract low-grade systemic inflammation, but there is a lack of consensus on how cytokines are modulated by training in adults with obesity. This study aimed of examining the effects of exercise training on circulating pro- and anti-inflammatory cytokines in adults with overweight and obesity, and whether exercise-induced fat mass reduction could mediate that effect. The search was conducted on Medline (Pubmed), SPORTDiscus and Web of Science databases from January 1998 to August 2021, using keywords pertaining to inflammation, exercise, and obesity. A total of 27 studies were selected, in which the circulating concentration levels of cytokines were analyzed. Endurance training (ET) decreased circulating CRP, IL-6 and TNF-α levels. TNF-α was reduced after resistance and concurrent training (CT), while IL-10 increased after resistance training (RT). Changes in IL-10 and CRP coincided with fat mass reduction, while decreased TNF-α levels were concomitant with changes in IL-6 and IL-10. Exercise training may reduce systemic low-grade inflammation profile in adults with overweight and obesity.

scholarly journals Study of TNF-α, IL-6 and Insulin Resistance in Type 2 Diabetes Mellitus at Vidharbha Region

2021 ◽  
pp. 534-539
Author(s):  
Ankita Kondhalkar ◽  
Rajan Barokar ◽  
Prajakta Warjukar ◽  
Roshan Kumar Jha
Keyword(s):  
Insulin Resistance ◽  
Diabetic Patients ◽  
Low Grade ◽  
Immunological Parameters ◽  
Insulin Synthesis ◽  
Immunological Markers ◽  
Chronic Hyperglycemia ◽  
Hematological Markers ◽  
Tnf Α ◽  
Low Grade Inflammation

Background: DM is a metabolic condition caused by deficiencies in insulin synthesis, insulin action, or both. It is characterised by chronic hyperglycemia and glycosuria, as well as abnormalities in carbohydrate, fat, and protein metabolism. Diabetes and its complications are believed to be caused by a variety of causes. Genetics, diet, sedentary lifestyle, perinatal causes, age, and obesity are among them.  The relationship and interaction of various risk factors with disease severity is still unknown, so the aim of the proposed study was to determine the possible relationship between biochemical markers glycosylated haemoglobin, lipid profile, insulin resistance, and immunological markers TNF- and IL-6, in order to suggest appropriate measures to reduce the country's diabetes burden. Materials and Methods: A total of 300 people were chosen for the study after visiting Shalinitai Meghe hospital in Nagpur for a health check-up. The three groups were contained in this area. Results: Both biochemical and immunological parameters rose in managed diabetic patients and significantly increased in uncontrolled diabetic patients, according to the report, but values did not differ between groups 1. Conclusion: Low-grade inflammation and inflammatory mediator upregulation have been suggested to play a role in T2DM etiology. TNF- and IL-6 have a positive connection with T2DM and insulin sensitivity, according to our data. These can be used as T2DM biomarkers in the early stages of the disease. To help doctors monitor and treat T2DM successfully, more research on a larger spectrum of pro and anti-inflammatory cytokines (mediators) in conjunction with other biochemical, immunoassay, and hematological markers is needed.

scholarly journals Palmitate-Induced MMP-9 Expression in the Human Monocytic Cells is Mediated through the TLR4-MyD88 Dependent Mechanism

2016 ◽  
Vol 39 (3) ◽  
pp. 889-900 ◽  
Author(s):  
Sardar Sindhu ◽  
Areej Al-Roub ◽  
Merin Koshy ◽  
Reeby Thomas ◽  
Rasheed Ahmad
Keyword(s):  
Underlying Mechanism ◽  
Positive Control ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Monocytic Cells ◽  
Metabolic Inflammation ◽  
Human Monocytic Cell Line ◽  
Tnf Α ◽  
Human Monocytic Cell

Background/Aims: Obese individuals are known to have increased Matrix metalloproteinase (MMP)-9 plasma levels and MMP-9 is reported to play an important role in obesity-associated adipose tissue inflammation. Since in obesity, the levels of circulatory saturated free fatty acid (FFA) palmitate (palimitic acid) are increased and modulate the expression of inflammatory mediators, the role of palmitate in the regulation of MMP-9 remains unclear. Methods: Human monocytic cell line THP-1 and primary monocytes were stimulated with palmitate and TNF-α (positive control). MMP-9 expression was assessed with real time RT-PCR and ELISA. Signaling pathways were studied by using THP-1-XBlue™ cells, THP-1-XBlue™-defMyD cells, anti-TLR4 mAb and TLR4 siRNA. Phosphorylation of NF-kB and c-Jun was analyzed by Western blotting. Results: Here, we provide the evidence that palmitate induces MMP-9 expression at both mRNA (THP-1: 6.8 ± 1.2 Fold; P = 0.01; Primary monocytes: 5.9 ± 0.7 Fold; P = 0.0003) and protein (THP1: 1116 ±14 pg/ml; P<0.001; Primary monocytes: 1426 ± 13.8; P = 0.0005) levels in human monocytic cells. Palmitate-induced MMP-9 secretion was markedly suppressed by neutralizing anti-TLR-4 antibody (P < 0.05). Furthermore, genetic silencing of TLR4 by siRNA also significantly abrogated the palmitate-induced up-regulation of MMP-9. Additionally, MyD88-/- THP-1 cells did not express MMP-9 in response to palmitate treatment. Increased NF-κB/AP-1 activity (P<0.05) was also observed in palmitate-treated THP-1 cells. Conclusion: Altogether, these results show that palmitate induces TLR4-dependent activation of MMP-9 gene expression, which requires the recruitment of MyD88 leading to activation of NF-kB/AP-1 transcription factors. Thus, our findings suggest that the palmitate-induced MMP-9 secretion might be an underlying mechanism of its increased levels in obesity and related metabolic inflammation.

scholarly journals MIP-1α Expression Induced by Co-Stimulation of Human Monocytic Cells with Palmitate and TNF-α Involves the TLR4-IRF3 Pathway and Is Amplified by Oxidative Stress

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1799
Author(s):  
Sardar Sindhu ◽  
Nadeem Akhter ◽  
Ajit Wilson ◽  
Reeby Thomas ◽  
Hossein Arefanian ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Inflammatory Cells ◽  
H2o2 Treatment ◽  
Monocytic Cells ◽  
Metabolic Inflammation ◽  
Genetic Ablation ◽  
Protein Levels ◽  
Inflammatory Protein ◽  
Tnf Α ◽  
In Cells

Metabolic inflammation is associated with increased expression of saturated free fatty acids, proinflammatory cytokines, chemokines, and adipose oxidative stress. Macrophage inflammatory protein (MIP)-1α recruits the inflammatory cells such as monocytes, macrophages, and neutrophils in the adipose tissue; however, the mechanisms promoting the MIP-1α expression remain unclear. We hypothesized that MIP-1α co-induced by palmitate and tumor necrosis factor (TNF)-α in monocytic cells/macrophages could be further enhanced in the presence of reactive oxygen species (ROS)-mediated oxidative stress. To investigate this, THP-1 monocytic cells and primary human macrophages were co-stimulated with palmitate and TNF-α and mRNA and protein levels of MIP-1α were measured by using quantitative reverse transcription, polymerase chain reaction (qRT-PCR) and commercial enzyme-linked immunosorbent assays (ELISA), respectively. The cognate receptor of palmitate, toll-like receptor (TLR)-4, was blunted by genetic ablation, neutralization, and chemical inhibition. The involvement of TLR4-downstream pathways, interferon regulatory factor (IRF)-3 or myeloid differentiation (MyD)-88 factor, was determined using IRF3-siRNA or MyD88-deficient cells. Oxidative stress was induced in cells by hydrogen peroxide (H2O2) treatment and ROS induction was measured by dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay. The data show that MIP-1α gene/protein expression was upregulated in cells co-stimulated with palmitate/TNF-α compared to those stimulated with either palmitate or TNF-α (P < 0.05). Further, TLR4-IRF3 pathway was implicated in the cooperative induction of MIP-1α in THP-1 cells, and this cooperativity between palmitate and TNF-α was clathrin-dependent and also required signaling through c-Jun and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Notably, ROS itself induced MIP-1α and could further promote MIP-1α secretion together with palmitate and TNF-α. In conclusion, palmitate and TNF-α co-induce MIP-1α in human monocytic cells via the TLR4-IRF3 pathway and signaling involving c-Jun/NF-κB. Importantly, oxidative stress leads to ROS-driven MIP-1α amplification, which may have significance for metabolic inflammation.

scholarly journals Inflammatory and metabolic responses to high-fat meals with and without dairy products in men

2015 ◽  
Vol 113 (12) ◽  
pp. 1853-1861 ◽  
Author(s):  
Alexandra Schmid ◽  
Nicolai Petry ◽  
Barbara Walther ◽  
Ueli Bütikofer ◽  
Werner Luginbühl ◽  
...  
Keyword(s):  
Dairy Products ◽  
Plasma Concentrations ◽  
Hdl Cholesterol ◽  
Metabolic Responses ◽  
Low Grade ◽  
High Fat ◽  
Reactive Protein ◽  
Tnf Α ◽  
Postprandial Inflammation ◽  
Low Grade Inflammation

Postprandial inflammation is an important factor for human health since chronic low-grade inflammation is associated with chronic diseases. Dairy products have a weak but significant anti-inflammatory effect on postprandial inflammation. The objective of the present study was to compare the effect of a high-fat dairy meal (HFD meal), a high-fat non-dairy meal supplemented with milk (HFM meal) and a high-fat non-dairy control meal (HFC meal) on postprandial inflammatory and metabolic responses in healthy men. A cross-over study was conducted in nineteen male subjects. Blood samples were collected before and 1, 2, 4 and 6 h after consumption of the test meals. Plasma concentrations of insulin, glucose, total cholesterol, LDL-cholesterol, HDL-cholesterol, TAG and C-reactive protein (CRP) were measured at each time point. IL-6, TNF-α and endotoxin concentrations were assessed at baseline and endpoint (6 h). Time-dependent curves of these metabolic parameters were plotted, and the net incremental AUC were found to be significantly higher for TAG and lower for CRP after consumption of the HFM meal compared with the HFD meal; however, the HFM and HFD meals were not different from the HFC meal. Alterations in IL-6, TNF-α and endotoxin concentrations were not significantly different between the test meals. The results suggest that full-fat milk and dairy products (cheese and butter) have no significant impact on the inflammatory response to a high-fat meal.

scholarly journals Resistance Exercise Training-Induced Muscle Hypertrophy Was Associated with Reduction of Inflammatory Markers in Elderly Women

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Kishiko Ogawa ◽  
Kiyoshi Sanada ◽  
Shuichi Machida ◽  
Mitsuharu Okutsu ◽  
Katsuhiko Suzuki
Keyword(s):  
Exercise Training ◽  
Resistance Exercise ◽  
Elderly Women ◽  
Muscle Thickness ◽  
The Elderly ◽  
Low Grade ◽  
Resistance Exercise Training ◽  
Tnf Α ◽  
Low Grade Inflammation ◽  
Circulating Levels

Aging is associated with low-grade inflammation. The benefits of regular exercise for the elderly are well established, whereas less is known about the impact of low-intensity resistance exercise on low-grade inflammation in the elderly. Twenty-one elderly women (mean age ± SD, 85.0 ± 4.5 years) participated in 12 weeks of resistance exercise training. Muscle thickness and circulating levels of C-reactive protein (CRP), serum amyloid A (SAA), heat shock protein (HSP)70, tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-6, monocyte chemotactic protein (MCP-1), insulin, insulin-like growth factor (IGF)-I, and vascular endothelial growth factor (VEGF) were measured before and after the exercise training. Training reduced the circulating levels of CRP, SAA (P<.05), HSP70, IGF-I, and insulin (P<.01). The training-induced reductions in CRP and TNF-α were significantly (P<.01,P<.05) associated with increased muscle thickness (r=−0.61,r=−0.54), respectively. None of the results were significant after applying a Bonferroni correction. Resistance training may assist in maintaining or improving muscle volume and reducing low-grade inflammation.

scholarly journals Human Models of Low-Grade Inflammation: Bolus versus Continuous Infusion of Endotoxin

2007 ◽  
Vol 14 (3) ◽  
pp. 250-255 ◽  
Author(s):  
S. Taudorf ◽  
K. S. Krabbe ◽  
R. M. G. Berg ◽  
B. K. Pedersen ◽  
K. Møller
Keyword(s):  
Continuous Infusion ◽  
Inflammatory Mediators ◽  
Low Dose ◽  
Bolus Injection ◽  
In Vivo Model ◽  
Low Grade ◽  
Necrosis Factor Alpha ◽  
Endotoxin Infusion ◽  
Tnf Α ◽  
Low Grade Inflammation

ABSTRACT Systemic low-grade inflammation is recognized in an increasing number of chronic diseases. With the aim of establishing an experimental human in vivo model of systemic low-grade inflammation, we measured circulating inflammatory mediators after intravenous administration of Escherichia coli endotoxin (0.3 ng/kg of body weight) either as a bolus injection or as a 4-h continuous intravenous infusion, as well as after saline administration, in 10 healthy male subjects on three separate study days. Only bolus endotoxin caused an increase in heart rate, whereas a slight increase in rectal temperature was observed in both endotoxin groups. Tumor necrosis factor alpha (TNF-α), interleukin-6, and neutrophil responses were earlier and more pronounced in the bolus trial compared with the infusion trial results, whereas lymphocytes increased after endotoxin bolus injection as well as infusion without any difference between groups. Finally, endotoxin activated the hypothalamo-pituitary-adrenal axis slightly earlier in the bolus compared to the infusion trial. The continuous endotoxin infusion model may be more representative of human low-grade inflammation than the bolus injection model due to a less dynamic and more sustained increase in circulating levels of inflammatory mediators over time. In conclusion, low-dose endotoxin infusion elicits an inflammatory response, as assessed by a rise in TNF-α, and the responses are significantly different according to whether low-dose endotoxin is applied as a bolus injection or as a continuous infusion.

scholarly journals Cardiorenal Syndrome in Hypertensive Rats: Microalbuminuria, Inflammation and Ventricular Hypertrophy

2012 ◽  
pp. 13-24 ◽  
Author(s):  
M. MOUBARAK ◽  
H. JABBOUR ◽  
V. SMAYRA ◽  
E. CHOUERY ◽  
Y. SALIBA ◽  
...  
Keyword(s):  
Ventricular Hypertrophy ◽  
Cardiorenal Syndrome ◽  
Left Ventricular ◽  
Low Grade ◽  
Necrosis Factor Alpha ◽  
Reactive Protein ◽  
Tnf Α ◽  
Male Wistar Rats ◽  
Factor Alpha ◽  
Low Grade Inflammation

The aim of our study was to evaluate a possible association between microalbuminuria (MA), several low-grade inflammation factors and left ventricular hypertrophy (LVH) by using a pharmacological approach. This may provide new insights into the pathophysiologic mechanisms of the cardiorenal syndrome (CRS) linking early renal impairment with elevated cardiovascular risk. Two kidney-one clip (2K-1C) renovascular hypertension was induced in 24 male Wistar rats (220-250 g). After the development of hypertension, rats were divided into four groups: 2K-1C (untreated), calcium channel blocker (amlodipine-treated), angiotensin receptor blocker (losartan-treated) and peripheral vasodilator (hydralazine-treated), which were treated for 10 weeks. Rats in the 2K-1C group had all developed hypertension, a significant increase in plasma levels of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), brain natriuretic peptide (BNP) and C-reactive protein (CRP). Moreover MA and creatininaemia underwent a significant increase. Under treatment decreases were observed in systolic blood pressure (SBP), TNF-α, CRP, IL-6, BNP concentrations and creatininaemia. These results were related to the absence of MA which was significantly associated with reductions in cardiac mass and hypertrophy markers (BNP and β-MHC gene expression) as well as renal interstitial inflammation. In conclusion, our results suggest that the reduction of MA is correlated with the decrease of the inflammatory components and seems to play an important role in protecting against cardiac hypertrophy and renal injury.

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