TNF-α Expression In Monocytes Research Articles

Analisis Jumlah Sel Monosit yang Mengekspresikan Tnf-Α setelah dipapar Porphyromonas Gingivalis dan Tulang Ikan Kuniran (Upeneus Sulphureus) dengan Teknik Imunositokimia

Monocytes play a role in the first defense against microorganisms that harm the body by activating nuclear factor kβ (Nf-kβ) which is the main regulator of inflammatory genes, one of which is TNF-α. TNF-α at excessive levels will cause tissue damage. Therefore an immunomodulator is needed which can regulate the body's immune system. One natural ingredient that acts as an immunomodulator is fish bones. Purpose of research: To analyze the effect of goatfish’s bone extract on TNF-α expression in human monocytes exposed to P. gingivalis. Method: experimental laboratories in vitro. TNF-α expression was tested by imunocytochemical techniques. Results: The results showed that the average number of monocytes expressing TNF-α in group P1 (group of diclofenac sodium) was 42.33 cells per cell. In the P2 group (P. gingivalis group) was 95 cell percent cells and for P3 (fish bone group) was 74.33 cells per cell and the control group was 11.66 cells per hundred cells. Conclusion: goatfish’s bone extract can act as an anti-inflammatory which is effective in reducing TNF-α expression in monocyte exposed to P. gingivalis but less effective than diclofenac sodium.

Increased Serum CD14 Level Is Associated with Depletion of TNF-α in Monocytes in Migraine Patients during Interictal Period.

The aim of the present study was to investigate the levels of circulating CD14 in relation to the expression of tumor necrosis factor alpha (TNF-α) in monocytes, and serum levels of TNF-α and macrophage inflammatory protein-1 (MIP-1) in migraine patients. Numerous studies revealed controversial changes in the components of the immune system during attacks and the interictal period in migraine patients. Our study included 40 migraineurs and 39 controls. The levels of TNF-α, MIP-1 and CD14 were measured in peripheral monocytes and in sera with the Enzyme-Linked Immunosorbent Assay (ELISA) method, and the monocyte expression of TNF-α was also analysed by immunostaining. Serum CD14 concentrations were higher and the expression of TNF-α in monocytes was decreased in migraineurs. The serum MIP-1 level correlated with Verbal Rating Scale (VRS); the MIP-1:CD14 ratio in monocytes correlated with Visual Analogue Scale (VAS); the MIP-1:CD14 ratio correlated with Migraine Severity (MIGSEV)-Pain scores; and serum CD14 concentration correlated with migraine duration in years. Increased serum CD14 and depletion of TNF-α in monocytes can orchestrate other components of the immune system during the interictal period.

Antiinflammatory properties of PAH drugs

In patients suffering from pulmonary arterial hypertension (PAH) elevated levels of monocyte-derived cytokines have been described in early stage of disease. Beside vasodilatory potential, specific anti-inflammatory activities of current PAH drugs might contribute to their therapeutic efficacy. We studied the anti-inflammatory properties of different classes of PAH drugs in human monocytes. CD14+ monocytes were isolated from blood taken from healthy donors with their informed consent. Cultured cells were stimulated with different concentrations of macitentan, riociguat, prostacyclin I2 analogues (iloprost, treprostinil) and the selective prostacyclin receptor agonist selexipag w/o LPS. For blocking experiments cells were pretreated with an inhibitor for the NfκB as well as the MAPK pathway, followed by incubation with LPS and the medications. The IL-6, IL-10 and TNF-α concentration of cell supernatants were measured with a commercially available ELISA based assay system. Only monocytes stimulated with iloprost or treprostinil showed a significant reduction of TNF-α, but no effect on the IL-6 and IL-10 release. The effect of treprostinil compared to iloprost was much stronger. The addition of the MAPK or NFκB inhibitor could further suppress the LPS-induced TNF-α expression. TNF-alpha suppression by prostacyclines has been described in various cell types and disease models. The detailed interaction between the cyclooxygenase system and the TLR-4 pathway still has to be elucidated. We show that PGI2 analogues suppress LPS induced TNF-α expression in monocytes via the MAPK and NFκB pathway, but in an IP receptor independent manner. This observation suggests a specific anti-inflammatory class effect of prostacyclin analogues in PAH therapy.

IL-10 disrupts the Brd4-docking sites to inhibit LPS-induced CXCL8 and TNF-α expression in monocytes: Implications for chronic obstructive pulmonary disease

IL-10 is well known for its ability to block the expression and production of numerous proinflammatory cytokines, in this manner preventing the development of excessive or chronic immune activation. IL-10-induced transcriptional repression of CXCL8 and TNFA genes consists of 2 distinct phases: an early phase, occurring rapidly and in a protein synthesis-independent manner, followed by a second phase that is more delayed and dependent on protein synthesis. We sought to identify the mechanisms through which IL-10 rapidly and directly suppresses LPS-induced CXCL8 and TNF-α transcription, which might be defective under pathologic conditions. The molecular events triggered by IL-10 in LPS-activated monocytes at the CXCL8 and TNFA loci were investigated by using the chromatin immunoprecipitation assay. Inhibition of LPS-induced CXCL8 and TNF-α expression by IL-10 proceeds through a common mechanism targeting LPS-induced phosphorylation of the nuclear factor κB p65 serine 276 residue (pS276p65). As a result, all the pS276p65-dependent events occurring at the CXCL8 and TNFA loci are consistently reduced, ultimately leading to a reduction in transcript elongation. Additionally, IL-10 selectively controls CXCL8 transcript elongation through histone deacetylase (HDAC) 2-dependent covalent chromatin modifications, disrupting the assembly of the transcriptional machinery. Remarkably, PBMCs from patients with acute-phase chronic obstructive pulmonary disease, which express negligible HDAC2 levels, are scarcely affected by IL-10 in terms of inhibition of CXCL8 expression. This study provides mechanistic evidence that IL-10 creates a chromatin environment that decreases the transcriptional rate of CXCL8 and TNF-α to Toll-like receptor 4-activating signals. Data identify novel molecular targets for therapeutic strategies aimed at dampening inflammation in pathologies such as chronic obstructive pulmonary disease, in which reduced intracellular HDAC2 levels have been described.

Rhodomyrtone modulates innate immune responses of THP-1 monocytes to assist in clearing methicillin-resistant Staphylococcus aureus.

BackgroundThe increasing resistance of Staphylococcus aureus to conventional antibiotics poses a major health problem. Moreover, S. aureus can survive within phagocytes, thus evading some antibiotics and the innate immune response. Rhodomyrtone, a bioactive compound from the leaves of Rhodomyrtus tomentosa, possesses potent antibacterial activity against methicillin-resistant S. aureus (MRSA). This study was to investigate the immunomodulatory effects of rhodomyrtone on THP-1 monocytes in response to MRSA.MethodsTHP-1 monocytes were stimulated with heat-killed MRSA, followed by treatment with rhodomyrtone. The cell pellets were prepared to detect pro-inflammatory molecules using real-time PCR. The supernatants were collected to assess nitric oxide production using Griess assay. Assays for phagocytosis and bacterial killing by THP-1 monocytes were performed to determine if they were affected by rhodomyrtone.ResultsExpression of pro-inflammatory molecules including IL-1β, TNF-α, IL-6, and iNOS was enhanced in THP-1 monocytes stimulated with high doses of heat-killed MRSA (108 to 109 cfu/ml). In contrast, monocytes stimulated with MRSA at lower doses (106 to 107 cfu/ml) did not induce the expression of these cytokines. However, rhodomyrtone significantly increased the expression of pro-inflammatory mediators, IL-6 and iNOS in monocytes stimulated with heat-killed MRSA at low doses, and displayed some anti-inflammatory activity by reducing TNF-α expression in monocytes stimulated with heat-killed MRSA at high doses. Treatment with rhodomyrtone also significantly up-regulated the expression of the key pattern recognition receptors, TLR2 and CD14, in THP-1 monocytes stimulated with heat-killed MRSA at 106 to 109 cfu/ml, while heat-killed MRSA alone did not induce the expression of these molecules. The ability of rhodomyrtone to eliminate MRSA from the monocytes was observed within 24 h after treatment.ConclusionRhodomyrtone enhanced the expression of pattern recognition receptors by monocytes in response to MRSA. Increased expression of these receptors might improve MRSA clearance by modulating pro- and anti-inflammatory cytokine responses.

Pro- and anti-inflammatory effects of histamine on tissue factor and TNFα expression in monocytes of human blood

Histamine is classified as an inflammatory mediator and has been reported to have anti- as well as pro-inflammatory properties. The aim of this study was to explore the role of histamine on the production of LPS-induced tissue factor (TF) activity and TNFα in monocytes of whole blood in the absence and presence of TNFα or PMA. Human blood anticoagulated with Fragmin was subjected to stimulation by LPS in the presence and absence of TNFα or PMA and various concentrations of histamine. Tissue factor (TF) activity was measured in lyzed cells after isolation of mononuclear cells whereas TNFα was quantified in plasma after centrifugation of cells. Histamine gave a dose dependent inhibitory effect on LPS-induced TF activity in monocytes of whole blood, with a 50% reduction at 0.033 μM. A similar effect was seen when the blood cells were stimulated with the combination of LPS and TNFα although TNFα enhanced LPS-induced TF activity almost two fold. In contrast, when blood was incubated with LPS and PMA in whole blood, histamine gave a significant rise in TF activity at 0.01 μM and 0.33 μM histamine. The effect of histamine was less at 0.1 μM or higher concentrations giving a biphasic profile. Contrary to the effect of histamine on LPS plus PMA induced TF activity, histamine caused a significant reduction in TNFα albeit less than in the absence of PMA. Intake of aspirin caused a significant rise in LPS-induced TF activity that was almost abolished by histamine at 0.033 μM. Our study shows that histamine has an anti-inflammatory effect on LPS and LPS/TNFα stimulated monocytes of whole blood. In contrast when blood cells are activated by a combination of LPS and PMA whereby PKC is activated, histamine has a procoagulant/pro-inflammatory effect through enhancement of TF activity expression.

Anti-β2GPI/β2GPI induced TF and TNF-α expression in monocytes involving both TLR4/MyD88 and TLR4/TRIF signaling pathways

Our previous study demonstrated that Toll-like receptor 4 (TLR4) could act as a co-receptor with annexin A2 (ANX2) mediating anti-β2-glycoprotein I/β2-glycoprotein I (anti-β2GPI/β2GPI)-induced tissue factor (TF) expression in human acute monocytic leukemia cell line THP-1. In the current study, we further explored the roles of TLR4 and its adaptors, MyD88 and TRIF, in anti-β2GPI/β2GPI-induced the activation of human blood monocytes and THP-1 cells and the relationship among TLR4, β2GPI and ANX2 in this process. The results showed that treatment of monocytes or THP-1 cells with anti-β2GPI/β2GPI complex could increase TF, MyD88, TRIF as well as TNF-α (tumor necrosis factor alpha) expression. These effects were blocked by addition of TAK-242, a blocker of signaling transduction mediated by the intracellular domain of TLR4. Moreover, TLR4/β2GPI/ANX2 complex could be detected in THP-1 cell lysates. Overall, our results indicate that anti-β2GPI/β2GPI complex induced TF and TNF-α expression involving both TLR4/MyD88 and TLR4/TRIF signaling pathways and TLR4 and its adaptors might be molecular targets for therapy of antiphospholipid syndrome (APS).

Human atherosclerotic plaque lipid extract promotes expression of proinflammatory factors in human monocytes and macrophage-like cells

ObjectiveThe potential of the atherogenic human carotid plaque to stimulate the inflammatory process was examined in human monocytes and macrophages, in vitro. Methods and resultsExposure of monocytes to human carotid plaque lipid extract (LE) elevated the transcription level of the proinflammatory cytokines, interleukin (IL)-1β and tumor necrosis factor (TNF)-α, by 2.9 and 100.2 fold, respectively (as determined by real time PCR), and induced TNF-α secretion (as measured by enzyme-linked immunosorbent assay). Furthermore, LE caused an increase of 1.3–3.1 fold in the mRNA expression of the proinflammatory factors, IL-1β, IL-6, TNF-α, cyclooxygenase-2 and intercellular adhesion molecule-1, in macrophage-like cells. In order to investigate the proinflammatory components in the extract, two fractions, obtained by silica gel separation of LE, were characterized. The cholesterol–oxysterol rich fraction was found to have the most significant proinflammatory effect. It caused an increase in TNF-α expression in monocytes, and upregulated IL-6, TNF-α, intercellular adhesion molecule-1 and cyclooxygenase 2 by 1.5–2.5 fold in macrophages. The triglyceride fraction had almost no effect on the cells. ConclusionsThe human carotid plaque lipid extract was demonstrated to promote inflammation, in vitro. These data support the atherogenic character of the plaque and imply that its lipid composition may have ramifications on the progress of atherosclerosis.

Prostaglandin I2 analogues suppress TNF-α expression in human monocytes via mitogen-activated protein kinase pathway

Although treatment for asthma control has improved a lot recently, refractory asthma is still a challenge for clinicians. Evidence revealed that anti-tumor necrosis factor (TNF)-α therapy may have potential in treating refractory asthma. Recently in an animal model, prostaglandin I(2) (PGI(2)) analogues can suppress the cardinal feature of asthma. However, whether PGI(2) analogues can regulate TNF-α expression in monocytes and the mechanism is not well-known. The human monocytes were pretreated with beraprost, iloprost and treprostinil, three PGI(2) analogues, before stimulation with lipopolysaccharide (LPS). TNF-α concentration of the cell supernatants was measured by ELISA. Intracellular signaling was investigated by Western blot. PGI(2) analogues suppressed LPS-induced TNF-α expression in THP-1 cells. CAY10449, an I prostanoid receptor antagonist, could reverse these effects. Beraprost increased intracellular cAMP level in THP1 cells. Forskolin, an adenylyl cyclase activator, could confer similar effect. LPS-induced TNF-α expression in THP-1 cells could be reversed by mitogen-activator protein kinase (MAPK)-p38, extracellular signal-related kinase (ERK) and c-Jun N-terminal kinase (JNK) inhibitors. Western blot revealed that beraprost suppressed MAPK phospho-p38, phosphor-JNK and phosphor-ERK expression. PGI(2) analogues suppressed LPS-induced TNF-α expression in THP-1 cells via the IP receptor-cAMP and the MAPK pathways. PGI(2) analogues may have potentiality to treat asthma.

S1593 S-Adenosylmethionine (SAM) Down-Regulates LPS-Inducible Phosphodiesterase 4 Activity, Increases cAMP Levels and Decreases TNFα Expression in Monocytes: Relevance to Alcoholic Liver Disease

carriers before anti-tuberculosis treatment. Results: Twenty (38.5%) HCV carriers and 15 (14.4%) non-carriers were found to have elevated serum aminotransferase levels (> twice the upper limit of normal or pre-treatment level) during treatment (p = 0.0014, OR = 3.71, 95% C.I. = 1.70-8.11). There was no HCV genotype difference between those with liver injury (genotype 1:2 = 14:6) and without liver injury (genotype 1:2 = 23:9). However, the HCV carriers with detectable pre-treatment serum HCV-RNA had higher incidence of liver injury than those without detectable pre-treatment HCV-RNA (11/18, 61.1% vs. 9/34, 26.8%, p = 0.019, OR = 4.37, 95% C.I. = 1.29-14.73). Among the 20 HCV carriers with liver injury, 4 were noted to have an increase of at least one log of serum HCV-RNA level compared to their pre-treatment baselines. If these 4 patients were attributed to HCVexacerbation rather than drug-related, the incidence of drug-related liver injury was still higher in HCV carriers (30.8%) than non-carriers (14.4%, p = 0.020, OR = 2.64, 95% C.I. = 1.18-5.89). In the 20 HCV carriers with liver injury, 12 patients continued anti-treatment without event. Anti-tuberculosis drugs were successfully re-introduced after serum aminotransferase levels returned to less than twice the upper limit of normal value in the other 8 HCV carriers. Conclusions: The chronic hepatitis C patients have higher risk of antituberculosis-related liver injury than non-carriers, especially in those with detectable pretreatment serum HCV-RNA. However, all the HCV carriers can tolerate the whole treatment course with continuous therapy or re-administration of anti-tuberculosis drugs in this study.

Proinflammatory and atherogenic activity of monocytes in Type 2 diabetes

Cytokines secreted by the monocyte–macrophage system play a key role in the progression of atherosclerotic lesions in Type 2 diabetes. The objectives of this study were to assess the influence of cytokine gene expression in monocytes from patients with Type 2 diabetes on direct markers of endothelial injury with regard to clinically manifest atherosclerosis. Methods Monocytes from 58 patients with Type 2 diabetes and from 22 age-matched healthy volunteers of a control group were isolated in order to assess expression of tumor necrosis factor α (TNFα), interleukin (IL)-6, IL-8 and IL-10 cytokines (RTPCR, Applied Biosystems). Thrombomodulin concentration was determined using a Diagnostica Stago Immunoenzymatic assay, and circulating endothelial cell numbers were assayed using immunofluorescence studies with CLB-HEC19 antibodies. Results In 28 patients, TNFα expression in monocytes was observed. In these patients, as compared to those with undetectable levels of this cytokine's expression, higher hemoglobin A 1c ( P=.012) and thrombomodulin ( P=.005) concentrations were found. IL-8 expression was determined in 36 patients. Higher expression of TNFα ( P=.048) and IL-8 ( P=.049) was detected in patients with peripheral arterial disease in contrast to those free from this complication. Conclusion TNFα and IL-8 play a significant role in the proatherogenic activity of monocytes in Type 2 diabetes. The TNFα-connected activity of monocytes may directly determine endothelial dysfunction and injury. The location of atherosclerosis should be taken into account in the assessment of the proinflammatory activity of peripheral blood monocytes.

Glycine increases mRNA adiponectin and diminishes pro-inflammatory adipokines expression in 3T3-L1 cells

Obesity and type 2 diabetes course with chronic low-grade inflammation, where adiponectin is down-regulated and pro-inflammatory markers, like interleukin (IL)-6, tumor necrosis factor alpha (TNF-α), and C-reactive protein (CRP), are up-regulated. A treatment option to improve the micro- and macro-complications in type 2 diabetes is the use of glycine, which has been demonstrated previously to increase the expression of anti-inflammatory cytokine IL-10 in monocytes and down-regulate the expression of TNF-α in monocytes and Kupffer cells. Recently, our group demonstrated that glycine decreases the pro-inflammatory plasmatic cytokines in type 2 diabetes. The aim of this study was to test the effect of glycine on adipokines expression in 3T3-L1 cells. Cells were grown and differentiated in the presence of 10 mM glycine. After 2 days of confluence, cells were differentiated to adipocytes in the same medium supplemented with insulin, dexamethasone, and 3-isobutyl-1-methylxanthine. The RNA was extracted at days 0 and 8 of differentiation (fibroblasts and mature adipocyte phenotypes, respectively). The expression of PPAR-γ (peroxisome proliferator-activated receptor-γ), adiponectin, resistin, IL-6 and TNF-α were analyzed by real-time PCR. We demonstrated that when 3T3-L1 cells were treated with glycine, IL-6, resistin and TNF-α mRNA expression was decreased, but surprisingly adiponectin and PPAR-γ were up-regulated. In all cases the values were statistically significant ( P < 0.05) between glycine treatment and controls. These results show that glycine improves the pro-inflammatory profile and up-regulates adiponectin gene expression. Therefore, glycine could be useful as a modulator of the pro-inflammatory state observed in obesity and type 2 diabetes.

Nitric oxide activates the expression of IRAK-M via the release of TNF-α in human monocytes

The activation of interleukin receptor associated kinases (IRAK) is an important event in several inflammatory processes. However, exposing monocytes to a nitric oxide (NO) donor inhibits the activity of IRAK-1 and its molecular interaction with TNF receptor associated factor-6 (TRAF6). Despite the fact that NO is known to regulate many events in the immune and vascular system, the mechanism that underlies this inhibition remains unknown. We have recently demonstrated that IRAK-M inhibits the TLR/IRAK pathway during endotoxin tolerance and thus, we hypothesized that IRAK-M may be involved in the inhibition of IRAK-1 activity in the presence of NO. Hence, we have analyzed the expression of IRAK-M in human monocytes following exposure to a NO donor (GSNO) and we have observed that GSNO was capable of inducing IRAK-M mRNA and protein expression 8 and 20 h after stimulation, respectively. It is known that NO induces the expression of TNF-α in monocytes and we found that exposure to TNF-α induced IRAK-M mRNA expression in human monocytes within 2 h of stimulation. Furthermore, the expression of IRAK-M induced by GSNO was inhibited by the presence of a blocking antibody raised against TNF-α. Thus, our data indicate that stimulation of human monocytes with a NO donor results in a clear induction of IRAK-M and this is dependent on the release of TNF-α by this kind of cells.