Regulation Of Toll-like Receptor 4 Research Articles

Physiological TLR4 regulation in human fetal membranes as an explicative mechanism of a pathological preterm case.

The integrity of human fetal membranes is crucial for harmonious fetal development throughout pregnancy. Their premature rupture is often the consequence of a physiological phenomenon that has been exacerbated. Beyond all the implied biological processes, inflammation is of primary importance and is qualified as 'sterile' at the end of pregnancy. In this study, complementary methylomic and transcriptomic strategies on amnion and choriodecidua explants obtained from the altered (cervix zone) and intact fetal membranes at term and before labour were used. By cross-analysing genome-wide studies strengthened by in vitro experiments, we deciphered how the expression of toll-like receptor 4 (TLR4), an actor in pathological fetal membrane rupture, is controlled. Indeed, it is differentially regulated in the altered zone and between both layers by a dual mechanism: (1) the methylation of TLR4 and miRNA promoters and (2) targeting by miRNA (let-7a-2 and miR-125b-1) acting on the 3'-UTR of TLR4. Consequently, this study demonstrates that fine regulation of TLR4 is required for sterile inflammation establishment at the end of pregnancy and that it may be dysregulated in the pathological premature rupture of membranes.

Evaluation of heat shock protein 70 and toll-like receptor 4 expression in gingival crevicular fluid in response to orthodontic forces.

The aim of this study was to assess the concentrations of heat shock protein 70 (HSP70) and toll-like receptor 4 (TLR4) during orthodontic tooth movement and to compare their levels with interleukin-1β (IL-1β), a well-known proinflammatory biomarker. This study consisted of 20 patients (8 males, 12 females; mean age 14.75 ± 2.34years) who needed maxillary premolar extraction and segmental canine distalization. Concentrations of HSP70, TLR4, and IL-1β were examined before extraction (T1), at the 1st (T2), 4th (T3), 7th (T4), 14th (T5), and 30th (T6) days of canine retraction by enzyme-linked immunosorbent assay analysis of gingival crevicular fluid samples. Statistical analyses were performed with repeated measure ANOVA and Spearman's rank correlation coefficient analysis (p < 0.05). HSP70 increased gradually from T1 to T6 and showed significant differences between T1-T6 and T2-T6 (T1:3.28 ± 0.92ng/ml; T2:3.72 ± 0.66ng/ml; T6:9.35 ± 2.45ng/ml). The lowest TLR4 concentration was at T1, peaked at T3 and remained constant afterwards with significant differences between T1-T3, T1-T4, and T1-T6 (T1:0.71 ± 0.02pg/ml; T3:1.04 ± 0.11pg/ml; T4:0.95 ± 0.06pg/ml; T6:1.00 ± 0.07pg/ml). IL-1β increased from T1 to T6 with significant differences between T1-T4, T1-T5, and T1-T6 (T1:55.71 ± 5.48pg/ml; T4:100.11 ± 16.92pg/ml; T5:103.71 ± 23.19pg/ml; T6:125.12 ± 22.04pg/ml). The increase in HSP70 and TLR4 from T2-T3 showed a significant correlation (r = 0.598; p = 0.005). The increased levels of HSP70, TLR4, and IL-1β show the contribution of these mediators to the inflammatory response from the early stages of orthodontic tooth movement. The regulation of HSP70, TLR4, and/or IL-1β secretion during orthodontic force application could provide alterations for desired optimal tooth movement.

MUC1 Mitigates Renal Injury and Inflammation in Endotoxin-Induced Acute Kidney Injury by Inhibiting the TLR4-MD2 Axis and Reducing Pro-inflammatory Macrophages Infiltration.

Sepsis is the leading cause of acute kidney injury (AKI) in critical care patients. A cornerstone of sepsis-associated AKI is dysregulated inflammation driven by excessive activation of Toll-like receptor 4 (TLR4) pathway. MUC1, a membrane-bound mucin expressed in both epithelial tubular cells and renal macrophages, has been shown to be involved in the regulation of TLRs. Therefore, we hypothesized that MUC1 could mitigate the renal inflammatory response to TLR4 activation. To test this hypothesis, we used a murine model of endotoxin-induced AKI by intraperitoneal injection of LPS. We showed that Muc1-/- mice have a more severe renal dysfunction, an increased activation of the tissular NF-kB pathway and secreted more pro inflammatory cytokines compare to Muc1+/+ mice. By flow cytometry, we observed that the proportion of M1 (pro-inflammatory) macrophages in the kidneys of Muc1-/- mice was significantly increased. In human and murine primary macrophages, we showed that MUC1 is only induced in M1 type macrophages and that macrophages derived from Muc1-/- mice secreted more pro-inflammatory cytokines. Eventually, in HEK293 cells, we showed that MUC1 cytosolic domain (CT) seems necessary for the negative regulation of TLR4 by proximity ligation assay, MUC1-CT is in close relationship with TLR4 and acts as a competitive inhibitor of the recruitment of MYD88. Overall our results support that in the context of endotoxin-induced AKI, MUC1 plays a significant role in controlling disease severity by regulating negatively the TLR4-MD2 axis.

Transplantation of umbilical cord blood mononuclear cells attenuates the expression of IL-1β via the TLR4/NF-κB pathway in hypoxic-ischemic neonatal rats

Objective:This study aims to observe the effects of transplantation of umbilical cord blood mononuclear cells (UCBMCs) on the expression of interleukin (IL)-1β and explore the mechanism via the toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) pathway in hypoxic-ischemic neonatal rats.Methods:Seven-day-old Sprague-Dawley neonatal rats were randomly divided into Sham, hypoxic-ischemic brain damage (HIBD), and UCBMC groups. The HIBD model was prepared by Rice-Vannucci method, and UCBMC were transplanted 24 h after HIBD in the UCBMC group. At 7 days after transplantation, changes in neurons and the TLR4 protein were examined by neuronal nuclei (NeuN)/TLR4 immunofluorescence staining. The expression of pNF-κB and IL-1β proteins was detected by immunohistochemical staining and enzyme linked immunosorbent assay (ELISA).Results:The percentage of NeuN+DAPI+ cells in the injured cortex in the UCBMC group was significantly higher than that in the HIBD group and lower than that in the Sham group (P &lt; 0.05). The number of NeuN+TLR4+DAPI+cells in the UCBMC group was significantly lower than that in the HIBD group (P &lt; 0.05) but higher than that in the Sham group (P &lt; 0.05). More pNF-κB+ cells were observed in the HIBD group than in Sham and UCBMC groups (P &lt; 0.05), and more pNF-κB+ cells were observed in the UCBMC group than in the Sham group (P &lt; 0.05). ELISA results showed that the IL-1β expression in the injured cerebral cortex in the UCMBC group was significantly lower than that in the HIBD group but remained higher than that in the Sham group (P &lt; 0.05).Conclusions:UCBMC transplantation could inhibit the IL-1β protein expression in the injured cortex, thereby alleviating HIBD in neonatal rats. The underlying mechanism might be associated with the down- regulation of TLR4 and pNF-κB proteins.

RETRACTED: MLL1 promotes migration and invasion of fibroblast-like synoviocytes in rheumatoid arthritis by activating the TRIF/NF-κB signaling pathway via H3K4me3 enrichment in the TLR4 promoter region

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. A corrigendum for this article was previously published which corrected issues within Figure 1, as detailed here: https://www.sciencedirect.com/science/article/pii/S1567576920337887?via%3Dihub. The journal was subsequently alerted to additional issues, including an associated PubPeer comment concerning the provenance of the flow cytometry data in Figure 1B, as detailed here: https://pubpeer.com/publications/AD39B667B4ACD09C930F532D0BD985; and here https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. As part of a journal investigation, the editorial team noticed that many of the Western blots contained within the article were pixelated. In addition, the published email address of the corresponding author (zhangyd78@126.com), differed from the version submitted to the journal (weiwu_drww@163.com). The journal asked the authors to provide a detailed explanation to these concerns and the associated raw data. The Authors did not respond to this request. The Editor-in-Chief assessed the case and decided to retract the article.

Up-regulation of miR-326 regulates pro-inflammatory cytokines targeting TLR-4 in buffalo granulosa cells

A genome-wide profiling of microRNA (miRNA) in endotoxin tolerant buffalo granulosa cells identified miR-326 amongst top-10 upregulated miRNAs. In this study, we have elucidated the role of miR-326 in granulosa cells in vitro. In-silico analysis revealed that miR-326 have binding site for 3′UTR of TLR-4 (Toll-like receptor 4). Transfection experiments showed that there was a significant inhibition of TLR-4 when miR-326 mimic was transfected to buffalo granulosa cells. Furthermore, when miR-326 transfected granulosa cells were exposed to LPS, followed by expression analysis of TLR-4 complex genes (TLR-4 and MyD88) and pro-inflammatory cytokines, we found a decreased expression of both TLR-4 complex and pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β). We also found that the expression of anti-inflammatory (IL-10) gene was upregulated. To the best of our knowledge, this is the first study that showed the regulation of TLR-4 using miR-326. The present findings on regulation of TLR-4 are important and would help in understanding innate immunity regulation under different patho-physiology.

Long-term aerobic exercise training-induced anti-inflammatory response and mechanisms: Focusing on the toll-like receptor 4 signaling pathway.

Toll-like receptor 4 (TLR-4), which regulate inflammatory reactions, has become a popular research topic in recent years. This article reviews the latest scientific evidence on the regulation of TLR-4 by regular aerobic exercise training. The literature shows that long-term regular aerobic exercise training can effectively attenuate the expression of TLR-4 in immune cells and regulate its downstream intracellular cascade, including the p38 and PI3K/Akt signaling pathways. This further reduces cytokines secretion by inflammatory cells, which enhances immune system. We consider that the scientific evidence that long-term aerobic exercise training improves the inflammatory response provides a reasonable basis for using aerobic exercise training as a treatment for patients.

Inhibitory effect of carvacrol on lipopolysaccharide-induced memory impairment in rats.

Neuroinflammation is an important process underlying a wide variety of neurodegenerative diseases. Carvacrol (CAR) is a phenolic monoterpene commonly used as a food additive due to its antibacterial properties, but it has also been shown to exhibit strong antioxidative, anti-inflammatory, and neuroprotective effects. Here, we sought to investigate the effects of CAR on inflammation in the hippocampus and prefrontal cortex, as well as the molecular mechanisms underlying these effects. In our study, lipopolysaccharide was injected into the lateral ventricle of rats to induce memory impairment and neuroinflammation. Daily administration of CAR (25, 50, and 100 mg/kg) for 21 days improved recognition, discrimination, and memory impairments relative to untreated controls. CAR administration significantly attenuated expression of several inflammatory factors in the brain, including interleukin-1β, tumor necrosis factor-α, and cyclooxygenase-2. In addition, CAR significantly increased expression of brain-derived neurotrophic factor (BDNF) mRNA, and decreased expression of Toll-like receptor 4 (TLR4) mRNA. Taken together, these results show that CAR can improve memory impairment caused by neuroinflammation. This cognitive enhancement is due to the anti-inflammatory effects of CAR medicated by its regulation of BDNF and TLR4. Thus, CAR has significant potential as an inhibitor of memory degeneration in neurodegenerative diseases.

MiRNA-200b improves hepatic fibrosis induced by CCL4 by regulating toll-like receptor 4 in mice.

To study the effect of miRNA-200b on hepatic fibrosis induced by CCl4 in mice. The C59BL/6 mice were randomly divided into three groups (normal control [NC], CCLR model [Model], and CCl 4 + miRNA-200b [miRNA]). The hepatic fibrosis was induced by CCl 4 injected subcutaneously twice per week in Model and miRNA groups. After 6 weeks building model, the mice of miRNA group were injected the miRNA-200b from caudal vein twice per week. The mice of Model and miRNA groups were continuously fed for 3 weeks. The IL-1β, IL-6, and TNF-α concentrations of serum were measured by enzyme-linked immunosorbent assay. The hepatic tissues of difference groups were observed by hematoxylin and eosin (H&E) staining, sirius red staining, Masson staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay and measured toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) proteins expressions by western blot assay. The correlation between miRNA-200b and TLR4 were analyzed by dual luciferase target assay. Compared with NC group, the interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) concentrations of Model group were significantly upregulated (P < 0.05, respectively). With miRNA-200b overexpression, the IL-1β, IL-6, and TNF-α concentrations were significantly suppressed (P < 0.05, respectively). The pathologies were improved by H&E staining, sirius red staining, and Masson staining; meanwhile, the hepatic cell apoptosis rate was significantly suppressed (P < 0.05). The TLR4 and NF-κB protein expressions of miRNA group were significantly suppressed compared with the Model group (P < 0.05, respectively). By dual luciferase target assay, the TLR4 was a target gene of miRNA-200b. The miRNA-200b upregulation improved hepatic fibrosis induced by CCl 4 via regulation of TLR4 in vivo.

The protective effects of salvianolic acid A against hepatic ischemia-reperfusion injury via inhibiting expression of toll-like receptor 4 in rats.

IntroductionIschemia-reperfusion injury (IRI) is a serious complication of hepatectomy and liver transplantation. The aim of this study was to evaluate the protective effects of salvianolic acid-A (Sal-A) against IRI-induced hepatocellular injury.Material and methodsForty rats were randomly divided into the following four groups: (1) sham group, (2) IR group, (3) Sal-A(10) group and (4) Sal-A(20) group. After 90 min of ischemia and 6 h of reperfusion, serum alanine aminotransferease (ALT) and apartate aminotransferase (AST) levels were measured; the amounts of malondialdehyde (MDA) and superoxide dismutase (SOD) in the liver tissue were determined; the expression of Bcl-2 and caspase-3 was detected and the severity of apoptosis, inflammation and pathological alterations were evaluated. Also apoptosis and mRNA and protein levels of TLR4 (toll-like receptor 4) were tested.ResultsThe serum aminotransferases, hepatic MDA concentration, and apoptotic cells in the IR group were significantly higher than in the sham group (p < 0.01), whereas the Sal-A group values were lower than in the IR group (p < 0.05). Compared with the IR group, the Sal-A groups had significantly higher Bcl-2 expression and downregulated cleaved caspase-3 expression in liver tissue. Moreover, increased mRNA and protein levels of TLR4 in IR rats and Sal-A could improve the increased mRNA and protein levels of TLR4.ConclusionsSal-A had a synergistically protective effect on the liver tissue against IRI that might be due to decreased oxidative stress, inflammation, hepatocellular apoptosis and include, at least in part, the regulation of TLR4.

Lactobacillus plantarum ameliorates tumour necrosis factor-induced bacterial translocation in Caco-2 cells by regulation of TLR4 expression.

Purpose. Translocation of bacteria across the intestinal barrier is important in the pathogenesis of systemic sepsis. In inflammatory conditions, commensal bacteria exploit transcytotic pathways to cross the intestinal epithelium in a TLR4-dependent manner. The aim of this study was to test the hypothesis that Lactobacillus plantarum ameliorates tumour necrosis factor-induced bacterial translocation by regulation of Toll-like receptor-4 expression.Methodology. L. plantarum strains were investigated to determine their capacity to inhibit the initial adhesion of Escherichia coli B5 to Caco-2 cells. The inhibitory effects of L. plantarum on TNF-α-induced E. coli B5 translocation across Caco-2 cells were studied. Barrier function and integrity were simultaneously assessed by transepithelial electrical resistance, HRP permeability, LDH release and distribution of tight junctional proteins. Expression of TLR4 was assessed by RT-PCR.Results/Key findings. Pretreatment of monolayers with L. plantarum L2 led to a significant decrease in E. coli B5 adhesion and cell internalization (P<0.01). Exposure to TNF-α for six hours caused a significant increase in E. coli B5 translocation across Caco-2 cells, which was uncoupled from increases in paracellular permeability and disruption of tight junction proteins. Manipulations that induced bacterial translocation were associated with a marked increase in TLR4 mRNA expression and IL-8 secretion. L. plantarum L2 significantly abrogated TNF-α-induced bacterial translocation of E. coli B5, and also downregulated expression of TLR4 and IL-8 in intestinal epithelial cells.Conclusion. Live L. plantarum L2 can inhibit TNF-α-induced transcellular bacterial translocation via regulation of TLR4 expression.

Regulation of TLR4 in silica-induced inflammation: An underlying mechanism of silicosis.

Silicosis is an incurable lung disease affecting millions of workers in hazardous occupations. It is caused by chronic exposure to the dust that contains free crystalline silica. Silica-induced lung damage occurs by several main mechanisms including cell death by apoptosis, fibrosis and production of cytokines. However, the signal pathways involved in these mechanisms are not fully characterized. In this study, the toll-like receptor 4 (TLR4)-related signal pathway was examined in silica-treated U937-differentiated macrophages. The expression level of TLR4 was measured by both quantitative PCR and Western blot. Confirmation of the involvement of MyD88/TIRAP and NFκB p65 cascade was performed by Western blot. The secretion of cytokines IL-1β, IL-6, IL-10 and TNFα was measured by enzyme-linked immunosorbent assay. Our results showed that TLR4 and related MyD88/TIRAP pathway was associated with silica-exposure in U937-differentiated macrophages. Protein expression of TLR4, MyD88 and TIRAP was upregulated when the U937-differentiated macrophages were exposed to silica. However, the upregulation was attenuated when TLR4 inhibitor, TAK-242 was present. At different incubation times of silica exposure, it was found that NFκB p65 cascade was activated at 10-60 minutes. Release of cytokines IL-1β, IL-6, IL-10 and TNFα was induced by silica exposure and the induction of IL-1β, IL-6 and TNFα was suppressed by the addition of TAK-242. In conclusion, our study demonstrated that TLR4 and related MyD88/TIRAP pathway was involved in silica-induced inflammation in U937-differentiated macrophages. Downstream NFκB p65 cascade was activated within 1 hour when the U937-differentiated macrophages were exposed to silica. The better understanding of early stage of silica-induced inflammatory process may help to develop earlier diagnosis of silicosis.

Schisantherin A attenuates ischemia/reperfusion-induced neuronal injury in rats via regulation of TLR4 and C5aR1 signaling pathways

Toll-like receptor 4 (TLR4) and C5aR1 (CD88) have been recognized as potential therapeutic targets for the reduction of inflammation and secondary damage and improvement of outcome after ischemia and reperfusion (I/R). The inflammatory responses which induce cell apoptosis and necrosis after I/R brain injury lead to a limited process of neural repair. To further comprehend how these targets function in I/R state, we investigated the pathological changes and TLR4 and C5aR1 signaling pathways in vitro and in vivo models of I/R brain injury in this study. Meanwhile, we explored the roles of schisantherin A on I/R brain injury, and whether it exerted neuroprotective effects by regulating the TLR4 and C5aR1 signaling pathways or not. The results showed that schisantherin A significantly reduced the neuronal apoptosis induced by oxygen and glucose deprivation and reperfusion (OGD/R) injury in primary culture of rat cortical neurons. Also, schisantherin A alleviated neurological deficits, reduced infarct volume, attenuated oxidation stress, inflammation and apoptosis in ischemic parietal cortex of rats after middle cerebral artery occlusion and reperfusion (MCAO/R) injury. Moreover, the activated TLR4 and C5aR1 signaling pathways were inhibited by schisantherin A treatment. In conclusion, TLR4 and C5aR1 played a vital role during I/R brain injury in rats, and schisantherin A exhibited neuroprotective effects by TLR4 and C5aR1 signaling pathways. These findings also provided new insights that would aid in elucidating the effect of schisantherin A against cerebral I/R and support the development of schisantherin A as a potential treatment for ischemic stroke.

Hypaphorine Attenuates Lipopolysaccharide-Induced Endothelial Inflammation via Regulation of TLR4 and PPAR-γ Dependent on PI3K/Akt/mTOR Signal Pathway.

Endothelial lesion response to injurious stimuli is a necessary step for initiating inflammatory cascades in blood vessels. Hypaphorine (Hy) from different marine sources is shown to exhibit anti-inflammatory properties. However, the potential roles and possible molecular mechanisms of Hy in endothelial inflammation have yet to be fully clarified. We showed that Hy significantly inhibited the positive effects of lipopolysaccharide (LPS) on pro-inflammatory cytokines expressions, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), monocyte chemoattractant protein 1 (MCP-1) and vascular cellular adhesion molecule-1 (VCAM-1), as well as induction of the phosphorylation of Akt and mTOR in HMEC-1 cells. The downregulated peroxisome proliferator-activated receptor γ (PPAR-γ) and upregulated toll-like receptor 4 (TLR4) expressions in LPS-challenged endothelial cells were prevented by Hy. Inhibition of both PI3K and mTOR reversed LPS-stimulated increases in TLR4 expressions and decreases in PPAR-γ levels. Genetic silencing of TLR4 or PPAR-γ agonist pioglitazone obviously abrogated the levels of pro-inflammatory cytokines in LPS-treated HMEC-1 cells. These results suggest that Hy may exert anti-inflammatory actions through the regulation of TLR4 and PPAR-γ dependent on PI3K/Akt/mTOR signal pathways. Hy may be considered as a therapeutic agent that can potentially relieve or ameliorate endothelial inflammation-associated diseases.

Herbal Compound "Jiedu Huayu" Reduces Liver Injury in Rats via Regulation of IL-2, TLR4, and PCNA Expression Levels.

Aim of the Study. To investigate the preventative effects of Jiedu Huayu (JDHY) on D-galactosamine (D-GalN) and lipopolysaccharide-induced acute liver failure (ALF) and to evaluate the possible mechanisms of action. Materials and Methods. ALF was induced in Wistar rats by administrating D-GalN (900 mg/kg) and lipopolysaccharide (10 μg/kg). After treatment with JDHY granules, the levels of blood alanine aminotransferase, aspartate aminotransferase, total bilirubin, and prothrombin time were determined. Proliferating cell nuclear antigen was detected by immunohistochemistry staining. The expression of interleukin-2 (IL-2) and toll-like receptor 4 (TLR4) was examined by fluorescence quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. Results. JDHY treatment dramatically improved liver function and increased survival rates in an ALF model in rats. We observed a decrease in IL-2 and TLR4 expression following treatment with JDHY in liver cells from ALF rats using qRT-PCR and Western blot analysis. Conclusion. We hypothesize that the therapeutic potential of JDHY for treating ALF is due to its modulatory effect on the suppression of inflammation and by promoting hepatocyte regeneration. Our results contribute towards validation of the traditional use of JDHY in the treatment of liver disease.

TLR4 induces CREB-mediated IL-6 production via upregulation of F-spondin to promote vascular smooth muscle cell migration

Toll-like receptor 4 (TLR4) is important in promoting inflammation and vascular smooth muscle cell (VSMC) migration, both of which contribute to atherosclerosis development and progression. But the mechanism underlying the regulation of TLR4 in VSMC migration remains unclear. Stimulation of VSMCs with LPS increased the cellular level of F-spondin which is associated with the regulation of proinflammatory cytokine production. The LPS-induced F-spondin expression depended on TLR4-mediated PI3K/Akt pathway. Suppression of F-spondin level by siRNA inhibited not only F-spondin expression but also LPS-induced phosphorylation of cAMP response element binding protein (CREB) and IL-6 expression, VSMC migration and proliferation as well as MMP9 expression. Moreover, suppression of CREB level by siRNA inhibited TLR4-induced IL-6 production and VSMC migration. Inhibition of F-spondin siRNA on LPS-induced migration was restored by addition of exogenous recombinant mouse IL-6. We conclude that upon ligand binding, TLR4 activates PI3K/Akt signaling to induce F-spondin expression, subsequently control CREB-mediated IL-6 production to promote VSMC migration. These findings provide vital insights into the essential role of F-spondin in VSMC function and will be valuable for developing new therapeutic strategies against atherosclerosis.

Selenium Deficiency Facilitates Inflammation Through the Regulation of TLR4 and TLR4-Related Signaling Pathways in the Mice Uterus.

Selenium (Se) is an essential nutritional trace element that affects the development and function of the reproductive system. Endometritis is a reproductive obstacle disease that can seriously reduce the reproductive capacity of animal. To study the effects of dietary Se deficiency on lipopolysaccharide (LPS)-induced mice endometritis, we generated a model of LPS-induced mice endometritis. The Se content in uterine tissues was detected by fluorescence spectrophotometry. The levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR). The extent of phosphorylation of IκBα, NF-κB p65, ERK, JNK, and p38 and the expression of Toll-like receptor 4 (TLR4) were detected with Western blots. The TLR4 messenger RNA (mRNA) was analyzed with qRT-PCR. The results indicated that dietary Se intake significantly influenced Se levels in uterine tissues. The Se-deficient mice model was successfully replicated, and Se deficiency exacerbated uterine tissue histopathology; increased the expression of TNF-α, IL-1β, and IL-6; facilitated the activation of TLR4; and enhanced the phosphorylation of IκBα, p65, ERK, JNK, and p38 in LPS-induced mice endometritis. Also, the effects were inhibited by a supplement of Se. In conclusion, our studies demonstrated that Se deficiency makes mice uterus more prone to inflammation. An appropriate Se supplement could enhance the immune condition of the uterus.

The Significance and Mechanism of Propofol on Treatment of Ischemia Reperfusion Induced Lung Injury in Rats

This study is aimed to investigate the efficacy and underlying the mechanism of propofol in treatment of ischemia reperfusion (IR)-induced lung injury in rats, providing a novel insight of therapeutic strategy for IR-induced lung injury. 120 healthy SD rats were selected and randomly divided into sham operation group, IR group, and propofol group (40 rats per group). Bronchoalveolar lavage fluid (BALF) protein content, serum protein content, lung permeability index, lung water content rate, methane dicarboxylic aldehyde (MDA) in lung tissue, superoxide dismutase (SOD), nitric oxide (NO), endothelin (ET-1), toll-like receptor 4 (TLR4), nuclear factor (NF-κB), and tumor necrosis factor-α (TNF-α) were examined and compared among different groups to evaluate the therapeutical effects of propofol on IR-induced lung injury and analyze the mechanism. In sham operation group, neither change in lung tissue nor pulmonary interstitial edema or alveolar wall damage was found under microscope; in IR group, marked pulmonary interstitial edema and alveolar wall damage complicated with inflammatory cell infiltration and hemorrhage were found; in propofol group, alveolar wall widening was observed, however, hemorrhage in alveolar cavity, inflammatory infiltration and tissue damage were less significant than in IR group. At 3 h after reperfusion, BALF protein content, lung permeability index, and lung water content rate were all significantly increased in IR group and propofol group, while the serum protein content was significantly lower than sham operation group (p < 0.05). Moreover, we found that the change of above parameters in propofol group was less significant than in IR group (p < 0.05). No statistically significant difference was found in ET-1 levels in different groups (p > 0.05). In contrast, MDA and NO in IR group and propofol group were significantly increased, while SOD activity was significantly decreased (p < 0.05). Furthermore, the change of above parameters in propofol group was less significant than in IR group (p < 0.05). In addition, mRNAs of TLR4, NF-κB, and TNF-α were significantly increased in IR group and propofol group (p < 0.05) with more significant change in IR group compared with propofol group (p < 0.05). Propofol has protective effects against IR-induced lung injury by improving activity of oxygen radical and restoring NO/ET-1 dynamic balance. Besides, regulation of TLR4, NF-κB, and TNF-α by propofol also play important role in alleviating IR-induced lung injury.

Interaction of PTPRO and TLR4 signaling in hepatocellular carcinoma.

Protein tyrosine phosphatase receptor type O (PTPRO) has been identified as a tumor suppressor in a number of cancers including hepatocellular carcinoma (HCC). Toll-like receptor 4 (TLR4) plays diverse roles in HCC tumorigenesis and progression. The association between PTPRO and TLR4 signaling in HCC remains largely unknown. We aimed to clarify the interaction between PTPRO and TLR4 in HCC. Surprisingly, we found reduced and positive-related expression of TLR4 and PTPRO in 84 human HCC specimens. Increased TLR4 expression and activity was found in PTPRO-overexpressed HCC cells stimulated with lipopolysaccharide (LPS). The feedback regulation of PTPRO and TLR4 was dependent on nuclear factor-κB (NF-κB) activation, as suggested by NF-κB inhibition and luciferase reporter assay. Our study suggests that the effect of PTPRO on TLR4 signaling is dependent on NF-κB pathway, suggesting an interesting PTPRO/TLR4/NF-κB signaling feedback loop in HCC carcinogenesis and progression.

Carnosic acid inhibits TLR4-MyD88 signaling pathway in LPS-stimulated 3T3-L1 adipocytes.

BACKGROUND/OBJECTIVESCarnosic acid (CA), found in rosemary (Rosemarinus officinalis) leaves, is known to exhibit anti-obesity and anti-inflammatory activities. However, whether its anti-inflammatory potency can contribute to the amelioration of obesity has not been elucidated. The aim of the current study was to investigate the effect of CA on Toll-like receptor 4 (TLR4) pathways in the presence of lipopolysaccharide (LPS) in 3T3-L1 adipocytes.MATERIALS/METHODS3T3-L1 adipocytes were treated with CA (0-20 µM) for 1 h, followed by treatment with LPS for 30 min; mRNA expression of adipokines and protein expression of TLR4-related molecules were then measured.RESULTSLPS-stimulated 3T3-L1 adipocytes showed elevated mRNA expression of tumor necrosis factor (TNF)-α, interleukin-6, and monocyte chemoattractant protein-1, and CA significantly inhibited the expression of these adipokine genes. LPS-induced up regulation of TLR4, myeloid differentiation factor 88, TNF receptor-associated factor 6, and nuclear factor-κB, as well as phosphorylated extracellular receptor-activated kinase were also suppressed by pre-treatment of 3T3-L1 adipocytes with CA.CONCLUSIONSResults of this study suggest that CA directly inhibits TLR4-MyD88-dependent signaling pathways and decreases the inflammatory response in adipocytes.