Toll-like receptor 4 and CD14 mRNA expression are lower in resistive exercise-trained elderly women

The purpose of this study was to examine the influence of resistive exercise training and hormone status on mRNA expression of toll-like receptor 4 (TLR4), CD14, IL-1β, IL-6, and TNF-α. Resistive exercise-trained women on “traditional” hormone replacements [hormone replacement therapy (HRT), n = 9], not taking hormones (NHR, n = 6), or taking medications known to influence bone (MIB, n = 7) were compared with untrained subjects not taking supplemental hormones (Con, n = 6). Blood was taken from trained subjects before, immediately after, and 2 h after resistive exercise (same time points for resting Con). TLR4 mRNA expression (RT-PCR) was not different among groups or across time but was significantly ( P = 0.044) lower (1.9-fold) when trained groups were collapsed and compared with Con. There was also a significant group effect ( P < 0.0001) for TLR4 mRNA when expressed per monocyte. CD14 expression was significantly ( P = 0.006) lower (2.3-fold) for training groups collapsed and compared with Con. CD14 mRNA, expressed per monocyte, was significantly lower immediately after resistive exercise for NHR, HRT, and MIB compared with Con. There were few significant effects detected for IL-6, IL-1β, and TNF-α mRNA, but there was a significant group effect ( P < 0.0001) for TNF-α mRNA expressed per monocyte (Con > HRT, NHR, MIB). These findings suggest that there may be a resistive exercise training-induced reduction in TLR4/CD14 expression in older women. Further research is needed to determine whether lower TLR4/CD14 could explain the lower LPS-stimulated inflammatory cytokines observed in these women.

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The Expression of Toll-Like Receptor 4 mRNA in PBMCs Is Upregulated in Smokers and Decreases Upon Smoking Cessation

Frontiers in Immunology ◽

10.3389/fimmu.2021.667460 ◽

2021 ◽

Vol 12 ◽

Author(s):

Hsin-Yu Yeh ◽

Shou-Hung Hung ◽

Su-Chiu Chen ◽

Fei-Ran Guo ◽

Hsien-Liang Huang ◽

...

Keyword(s):

Smoking Cessation ◽

Cigarette Smoking ◽

Mrna Expression ◽

Mononuclear Cells ◽

Intercellular Adhesion Molecule ◽

Mrna Levels ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Tlr4 Mrna ◽

Tnf Α

BackgroundStudies have shown in vitro that cigarette smoke condensate stimulates monocytes to express toll-like receptor 4 (TLR4), tumor necrosis factor-α (TNF-α), and intercellular adhesion molecule 1 (ICAM-1), and enhances their adhesion to the endothelium. However, the same effects of cigarette smoking have not been explored in vivo. This study is to investigate the effect of cigarette smoking and smoking cessation on their mRNA expression in human peripheral blood mononuclear cells (PBMCs).MethodsA group of 97 smokers and 62 nonsmokers were enrolled. The RNA from PBMCs was assessed with real-time polymerase chain reaction (PCR) to determine the levels of ICAM-1, TNF-α, and TLR4. The same markers in PBMCs of 87 quitters were examined before and at one week, one month, and two months after smoking cessation.ResultsOf the 97 smokers, 85 (87.6%) were males, and 30 (48.4%) of the nonsmokers were males (p < 0.0001). The mean (SD) age of the smokers was 43.24 (10.89) years, which was younger than 43.45 (11.41) years of nonsmokers (p < 0.0001). The incidence of cardiovascular diseases was 13.4% in smokers, which was higher than 1.6% in nonsmokers (p < 0.05). Both ICAM-1 and TNF-α mRNA levels in PBMCs were higher among the smokers (p < 0.0001). In addition, TLR4 mRNA levels in PBMCs were statistically elevated in the smokers (p < 0.0001) comparing with those in the nonsmokers. The mRNA levels of TLR4 and TNF-α in PBMCs decreased in those who had quit smoking for 2 months (p < 0.0001).ConclusionsICAM-1, TNF-α, and TLR4 mRNA expression levels in PBMCs increased in smokers and decreased after being on a smoking cessation program for 2 months. This finding suggested that TLR4 expression may mediate the atherogenic inflammatory process induced by smoking.

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Atorvastatin suppresses LPS-induced rapid upregulation of Toll-like receptor 4 and its signaling pathway in endothelial cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01335.2008 ◽

2011 ◽

Vol 300 (5) ◽

pp. H1743-H1752 ◽

Cited By ~ 38

Author(s):

Ying Wang ◽

Ming Xiang Zhang ◽

Xiao Meng ◽

Fu Qiang Liu ◽

Guang Sheng Yu ◽

...

Keyword(s):

Endothelial Cells ◽

Mrna Expression ◽

Signaling Pathways ◽

P38 Mapk ◽

Umbilical Vein ◽

Enzyme Linked Immunosorbent Assay ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Mapk Phosphorylation ◽

Tlr4 Mrna

In the present study, we tested our hypothesis that atorvastatin exerts its anti-inflammation effect via suppressing LPS-induced rapid upregulation of Toll-like receptor 4 (TLR4) mRNA and its downstream p38, ERK, and NF-κB signaling pathways in human umbilical-vein endothelial cells (HUVECs) and human aortic endothelial cells (HAECs). TLR4 mRNA expression and its downstream kinase activities induced by LPS alone or atorvastatin + LPS in endothelial cells were quantified using quantitative real-time PCR and enzyme-linked immunosorbent assay. Preincubation of LPS-stimulated endothelial cells with TLR4 siRNA was conducted to identify the target of the anti-inflammatory effects of atorvastatin. Atorvastatin incubation resulted in the reduction of LPS-induced TLR4 mRNA expression, ERK1/2 and P38 MAPK phosphorylation, and NF-κB binding activity. Pretreatment with MEK/ERK1/2 inhibitor PD98059 attenuated atorvastatin + LPS-induced NF-κB activity but had no effect on P38 MAPK phosphorylation. In contrast, pretreatment with P38 MAPK inhibitor SB203580 resulted in upregulation of atorvastatin + LPS-induced ERK1/2 phosphorylation but had no significant effects on NF-κB activity. On the other hand, blocking NF-κB with SN50 produced no effects on atorvastatin + LPS-induced ERK1/2 and P38 MAPK phosphorylation. Moreover, TLR4 gene silencing produced the same effects as the atorvastatin treatment. In conclusion, atorvastatin downregulated TLR4 mRNA expression by two distinct signaling pathways. First, atorvastatin stabilized Iκ-Bα, which directly inhibited NF-κB activation. Second, atorvastatin inactivated ERK phosphorylation, which indirectly inhibited NF-κB activation. Suppression of p38 MAPK by atorvastatin upregulates ERK but exerts no effect on NF-κB.

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Asparagine attenuates hepatic injury caused by lipopolysaccharide in weaned piglets associated with modulation of Toll-like receptor 4 and nucleotide-binding oligomerisation domain protein signalling and their negative regulators

British Journal Of Nutrition ◽

10.1017/s0007114515001476 ◽

2015 ◽

Vol 114 (2) ◽

pp. 189-201 ◽

Cited By ~ 4

Author(s):

Huanting Wu ◽

Yulan Liu ◽

Dingan Pi ◽

Weibo Leng ◽

Huiling Zhu ◽

...

Keyword(s):

Protein Expression ◽

Mrna Expression ◽

Nucleotide Binding ◽

Toll Like Receptor ◽

Negative Regulators ◽

Toll Like Receptor 4 ◽

Signalling Molecules ◽

Lps Challenge ◽

Tnf Α ◽

Domain Protein

Pro-inflammatory cytokines play a key role in many models of hepatic damage. In addition, asparagine (Asn) plays an important role in immune function. We aimed to investigate whether Asn could attenuate lipopolysaccharide (LPS)-induced liver damage. Forty-eight castrated barrows were allotted to four groups including: (1) non-challenged control; (2) LPS-challenged control; (3) LPS+0·5 % Asn; and (4) LPS+1·0 % Asn. After 19 d feeding with control, 0·5 or 1·0 % Asn diets, pigs were injected with LPS or saline. Blood and liver samples were obtained at 4 h (early stage) and 24 h (late stage) post-injection. Asn alleviated liver injury, indicated by reduced serum aspartate aminotransferase and alkaline phosphatase activities linearly and quadratically; it increased claudin-1 protein expression linearly and quadratically at 24 h, and less severe liver morphological impairment at 4 or 24 h. In addition, Asn decreased mRNA expression of TNF-α and heat shock protein 70 (HSP70) linearly and quadratically at 4 h; it increased TNF-α mRNA expression, and HSP70 protein expression linearly and quadratically at 24 h. Moreover, Asn increased inducible NO synthase activity linearly and quadratically. Finally, Asn down-regulated the mRNA expression of Toll-like receptor 4 (TLR4) signalling molecules (TLR4, IL-1 receptor-associated kinase 1 (IRAK1), TNF-α receptor-associated factor 6), nucleotide-binding oligomerisation domain protein (NOD) signalling molecules (NOD1, NOD2 and their adaptor molecule receptor-interacting serine/threonine-protein kinase 2 (RIPK2)), and NF-κB p65 linearly or quadratically at 4 h. Oppositely, Asn up-regulated mRNA expressions of TLR4 and NOD signalling molecules (TLR4, myeloid differentiation factor 88, IRAK1, NOD2 and RIPK2), and their negative regulators (radioprotective 105, single Ig IL-1R-related molecule, Erbb2 interacting protein and centaurin β1) linearly or quadratically at 24 h. These results indicate that, in early and late stages of LPS challenge, Asn improves liver integrity and exerts different regulatory effects on mRNA expression of TLR4 and NOD signalling molecules.

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Ventricular TLR4 Levels Abrogate TLR2-Knockout-Mediated Adverse Cardiac Remodeling upon Pressure Overload in Mice

International Journal of Molecular Sciences ◽

10.3390/ijms222111823 ◽

2021 ◽

Vol 22 (21) ◽

pp. 11823

Author(s):

Elise L. Kessler ◽

Jiong-Wei Wang ◽

Bart Kok ◽

Maike A. Brans ◽

Angelique Nederlof ◽

...

Keyword(s):

Mrna Expression ◽

Cardiac Remodeling ◽

Pressure Overload ◽

Heart Weight ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Cross Sectional ◽

Tlr4 Mrna ◽

Tibia Length

Involvement of the Toll-like receptor 4 (TLR4) in maladaptive cardiac remodeling and heart failure (HF) upon pressure overload has been studied extensively, but less is known about the role of TLR2. Interplay and redundancy of TLR4 with TLR2 have been reported in other organs but were not investigated during cardiac dysfunction. We explored whether TLR2 deficiency leads to less adverse cardiac remodeling upon chronic pressure overload and whether TLR2 and TLR4 additively contribute to this. We subjected 35 male C57BL/6J mice (wildtype (WT) or TLR2 knockout (KO)) to sham or transverse aortic constriction (TAC) surgery. After 12 weeks, echocardiography and electrocardiography were performed, and hearts were extracted for molecular and histological analysis. TLR2 deficiency (n = 14) was confirmed in all KO mice by PCR and resulted in less hypertrophy (heart weight to tibia length ratio (HW/TL), smaller cross-sectional cardiomyocyte area and decreased brain natriuretic peptide (BNP) mRNA expression, p < 0.05), increased contractility (QRS and QTc, p < 0.05), and less inflammation (e.g., interleukins 6 and 1β, p < 0.05) after TAC compared to WT animals (n = 11). Even though TLR2 KO TAC animals presented with lower levels of ventricular TLR4 mRNA than WT TAC animals (13.2 ± 0.8 vs. 16.6 ± 0.7 mg/mm, p < 0.01), TLR4 mRNA expression was increased in animals with the largest ventricular mass, highest hypertrophy, and lowest ejection fraction, leading to two distinct groups of TLR2 KO TAC animals with variations in cardiac remodeling. This variation, however, was not seen in WT TAC animals even though heart weight/tibia length correlated with expression of TLR4 in these animals (r = 0.078, p = 0.005). Our data suggest that TLR2 deficiency exacerbates adverse cardiac remodeling and that ventricular TLR2 and TLR4 additively contribute to adverse cardiac remodeling during chronic pressure overload. Therefore, both TLRs may be therapeutic targets to prevent or interfere in the underlying molecular processes.

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Intra-uterine Growth Restriction Downregulates the Hepatic Toll Like Receptor-4 Expression and Function

Clinical and Developmental Immunology ◽

10.1080/17402520400008905 ◽

2005 ◽

Vol 12 (1) ◽

pp. 59-66 ◽

Cited By ~ 14

Author(s):

Ozlem Equils ◽

Sapna Singh ◽

Semra Karaburun ◽

Daning Lu ◽

Manikkavasagar Thamotharan ◽

...

Keyword(s):

Mrna Expression ◽

Growth Restriction ◽

Milk Intake ◽

Mrna Levels ◽

Toll Like Receptor ◽

Tlr4 Expression ◽

Tlr4 Mrna ◽

Increased Risk ◽

Tnf Α ◽

And Function

Maternal starvation is a significant cause of intrauterine growth restriction (IUGR) in the world and increases the risk of infection in the neonate. We examined the effect of maternal starvation on Toll like receptor (TLR)4 expression in hepatic, splenic and intestinal tissues obtained from the adult IUGR offspring of prenatal calorie restricted rats. The hepatic TLR4 protein concentration was undetectable in the IUGR rats that had restricted milk intake during the suckling period (SM/SP;n= 4,p< 0.05) as compared to the normal growth controls (CM/CP;n=4), and access to ad lib milk intake during the sucking period partially corrected the hepatic TLR4 expression (SM/CP;n= 4). IUGR had no effect on the splenic (n= 4) or intestinal (n= 4) TLR4 mRNA levels. In the liver, IUGR led to a 20% increase in baseline tumor necrosis factor (TNF)-α mRNA expression (p< 0.03) and a 70% increase in interleukin-1β (IL-1β) mRNA expression (p< 0.008) as compared to the control rats (CM/CP;n= 7). LPS-induced hepatic TNF-α release was significantly higher in SM/SP as compared to CM/CP. We propose that IUGR dysregulates TLR4 expression and function in the offspring, which may help explain the increased risk of Gram-negative sepsis and inflammatory diseases in this population.

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Lipopolysaccharide stimulates nitric oxide synthase-2 expression in murine skeletal muscle and C2C12myoblasts via Toll-like receptor-4 and c-Jun NH2-terminal kinase pathways

AJP Cell Physiology ◽

10.1152/ajpcell.00010.2004 ◽

2004 ◽

Vol 287 (6) ◽

pp. C1605-C1615 ◽

Cited By ~ 43

Author(s):

Robert A. Frost ◽

Gerald J. Nystrom ◽

Charles H. Lang

Keyword(s):

Nitric Oxide ◽

Skeletal Muscle ◽

Nitric Oxide Synthase ◽

Mrna Expression ◽

Dominant Negative ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Tlr4 Mrna ◽

Oxide Synthase

The inducible form of nitric oxide synthase (NOS2) catalyzes the synthesis of nitric oxide (NO) from arginine in response to injury and infection. NOS2 is expressed predominantly by macrophages and lymphocytes. However, skeletal muscle also expresses NOS2 in response to inflammatory stimuli. The present study sought to determine whether lipopolysaccharide (LPS) stimulates NOS2 in skeletal muscle via Toll-like receptor-4 (TLR4). Intraperitoneal injection of LPS in wild-type mice (C3H/HeSnJ) increased NOS2 mRNA fourfold in skeletal muscle, while no change in NOS2 mRNA was observed in C3H/HeJ mice that harbored a mutation in the LPS receptor. NOS2 coimmunoprecipitated with the muscle-specific caveolin-3 protein, suggesting that myofibers per se respond to LPS in vivo. LPS stimulated NOS2 mRNA expression in C2C12myocytes, and the regulation of NOS2 mRNA was comparable in myoblasts and differentiated myotubes. LPS transiently stimulated the phosphorylation of the interleukin-1 receptor-associated kinase (IRAK-1) in C2C12cells and decreased the total amount of IRAK-1 both in vitro and in vivo over time. LPS stimulated the expression of an NF-κβ reporter plasmid, and this was inhibited by the proteasomal inhibitor MG-132. Both myoblasts and myotubes expressed TLR2 and TLR4 mRNA. Expression of a dominant negative form of TLR4 in C2C12cells blocked LPS-induced NF-κβ reporter activity. SP-600125 [a c-Jun NH2-terminal kinase (JNK) inhibitor] also prevented LPS stimulation of NOS2 expression. Moreover, the JNK inhibitor prevented the LPS-induced increase in NO synthesis. These data indicate that LPS increases NOS2 mRNA expression in muscle via a TLR4-dependent mechanism.

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Serum Amyloid A1/Toll-Like Receptor-4 Axis, an Important Link between Inflammation and Outcome of TBI Patients

Biomedicines ◽

10.3390/biomedicines9060599 ◽

2021 ◽

Vol 9 (6) ◽

pp. 599

Author(s):

Víctor Farré-Alins ◽

Alejandra Palomino-Antolín ◽

Paloma Narros-Fernández ◽

Ana Belen Lopez-Rodriguez ◽

Céline Decouty-Perez ◽

...

Keyword(s):

Injury Severity ◽

White Blood Cells ◽

Serum Amyloid ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Important Link ◽

Tlr4 Mrna ◽

Serum Amyloid A1

Traumatic brain injury (TBI) is one of the leading causes of mortality and disability worldwide without any validated biomarker or set of biomarkers to help the diagnosis and evaluation of the evolution/prognosis of TBI patients. To achieve this aim, a deeper knowledge of the biochemical and pathophysiological processes triggered after the trauma is essential. Here, we identified the serum amyloid A1 protein-Toll-like receptor 4 (SAA1-TLR4) axis as an important link between inflammation and the outcome of TBI patients. Using serum and mRNA from white blood cells (WBC) of TBI patients, we found a positive correlation between serum SAA1 levels and injury severity, as well as with the 6-month outcome of TBI patients. SAA1 levels also correlate with the presence of TLR4 mRNA in WBC. In vitro, we found that SAA1 contributes to inflammation via TLR4 activation that releases inflammatory cytokines, which in turn increases SAA1 levels, establishing a positive proinflammatory loop. In vivo, post-TBI treatment with the TLR4-antagonist TAK242 reduces SAA1 levels, improves neurobehavioral outcome, and prevents blood–brain barrier disruption. Our data support further evaluation of (i) post-TBI treatment in the presence of TLR4 inhibition for limiting TBI-induced damage and (ii) SAA1-TLR4 as a biomarker of injury progression in TBI patients.

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Differential Induction of the Toll-Like Receptor 4-MyD88-Dependent and -Independent Signaling Pathways by Endotoxins

Infection and Immunity ◽

10.1128/iai.73.5.2940-2950.2005 ◽

2005 ◽

Vol 73 (5) ◽

pp. 2940-2950 ◽

Cited By ~ 131

Author(s):

Susu M. Zughaier ◽

Shanta M. Zimmer ◽

Anup Datta ◽

Russell W. Carlson ◽

David S. Stephens

Keyword(s):

Nitric Oxide ◽

Signaling Pathways ◽

Lipid A ◽

Raw 264.7 ◽

Receptor Complex ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Nitric Oxide Release ◽

Tnf Α ◽

Dependent Pathway

ABSTRACT The biological response to endotoxin mediated through the Toll-like receptor 4 (TLR4)-MD-2 receptor complex is directly related to lipid A structure or configuration. Endotoxin structure may also influence activation of the MyD88-dependent and -independent signaling pathways of TLR4. To address this possibility, human macrophage-like cell lines (THP-1, U937, and MM6) or murine macrophage RAW 264.7 cells were stimulated with picomolar concentrations of highly purified endotoxins. Harvested supernatants from previously stimulated cells were also used to stimulate RAW 264.7 or 23ScCr (TLR4-deficient) macrophages (i.e., indirect induction). Neisseria meningitidis lipooligosaccharide (LOS) was a potent direct inducer of the MyD88-dependent pathway molecules tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 3α (MIP-3α), and the MyD88-independent molecules beta interferon (IFN-β), nitric oxide, and IFN-γ-inducible protein 10 (IP-10). Escherichia coli 55:B5 and Vibrio cholerae lipopolysaccharides (LPSs) at the same pmole/ml lipid A concentrations induced comparable levels of TNF-α, IL-1β, and MIP-3α, but significantly less IFN-β, nitric oxide, and IP-10. In contrast, LPS from Salmonella enterica serovars Minnesota and Typhimurium induced amounts of IFN-β, nitric oxide, and IP-10 similar to meningococcal LOS but much less TNF-α and MIP-3α in time course and dose-response experiments. No MyD88-dependent or -independent response to endotoxin was seen in TLR4-deficient cell lines (C3H/HeJ and 23ScCr) and response was restored in TLR4-MD-2-transfected human embryonic kidney 293 cells. Blocking the MyD88-dependent pathway by DNMyD88 resulted in significant reduction of TNF-α release but did not influence nitric oxide release. IFN-β polyclonal antibody and IFN-α/β receptor 1 antibody significantly reduced nitric oxide release. N. meningitidis endotoxin was a potent agonist of both the MyD88-dependent and -independent signaling pathways of the TLR4 receptor complex of human macrophages. E. coli 55:B5 and Vibrio cholerae LPS, at the same picomolar lipid A concentrations, selectively induced the MyD88-dependent pathway, while Salmonella LPS activated the MyD88-independent pathway.

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TNF-α Activates High-Mobility Group Box 1 - Toll-Like Receptor 4 Signaling Pathway in Human Aortic Endothelial Cells

Cellular Physiology and Biochemistry ◽

10.1159/000445570 ◽

2016 ◽

Vol 38 (6) ◽

pp. 2139-2151 ◽

Cited By ~ 16

Author(s):

Won Seok Yang ◽

Nam Jeong Han ◽

Jin Ju Kim ◽

Mee Jeong Lee ◽

Su-Kil Park

Keyword(s):

Signal Transduction ◽

Endothelial Cells ◽

High Mobility ◽

Neutralizing Antibody ◽

High Mobility Group ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Aortic Endothelial Cells ◽

Tnf Α ◽

Human Aortic Endothelial Cells

Background/Aims: Toll-like receptor 4 (TLR4) interacts with endogenous substances as well as lipopolysaccharide. We explored whether TLR4 is implicated in tumor necrosis factor-α (TNF-α) signal transduction in human aortic endothelial cells. Methods: The pathway was evaluated by transfection of siRNAs, immunoprecipitation and Western blot analysis. Results: TNF-α activated spleen tyrosine kinase (Syk) within 10 min, which led to endothelin-1 (ET-1) production. TLR4 was also rapidly activated by TNF-α stimulation, as shown by recruitment of interleukin-1 receptor-associated kinase 1 to TLR4 and its adaptor molecule, myeloid differentiation factor 88 (MyD88). siRNA depletion of TLR4 markedly attenuated TNF-α-induced Syk activation and ET-1 production. TLR4 inhibitor (CLI-095), TLR4-neutralizing antibody and siRNA depletion of MyD88 also attenuated TNF-α-induced Syk activation. Syk was co-immunoprecipitated with TLR4, and TNF-α activated Syk bound to TLR4. High-mobility group box 1 (HMGB1) was rapidly released and associated with TLR4 after TNF-α stimulation with a peak at 5 min, which was prevented by N-acetylcysteine, an antioxidant. Glycyrrhizin (HMGB1 inhibitor), HMGB1-neutralizing antibody and siRNA depletion of HMGB1 all suppressed TNF-α-induced Syk activation and ET-1 production. Conclusion: Upon TNF-α stimulation, TLR4 is activated by HMGB1 that is immediately released after the generation of reactive oxygen species, and plays a crucial role in the signal transduction.

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