OBJECTIVETo investigate the mechanism of polymyxin B (PMB) antagonizing the biological activity of lipopolysaccharide (LPS).

METHODSThe affinity of PMB for LPS and lipid A was assayed by biosensor, and the neutralization of PMB for LPS (2 ng/ml) was detected by kinetic turbidimetric limulus test. The releases of TNF-alpha and IL-6 in murine peritoneal macrophages a (PMphi) after exposure to LPS (100 ng/ml) were detected, and the expression levels of TLR4, TNF-alpha and IL-6 mRNA in PMphi induced by LPS (100 ng/ml) were measured by RT-PCR.

RESULTSPMB had high-affinity to LPS and lipid A with dissociation equilibrium constants of 18.9 nmol/L and 11.1 nmol/L, respectively, and neutralized LPS in a dose-dependent manner. Furthermore, PMB could markedly inhibit the expressions of TLR4, TNF-alpha and IL-6 mRNA and the release of cycokines in LPS-stimulated murine peritoneal macrophages.

CONCLUSIONSPMB neutralizes LPS and inhibites the expression and release of cycokines in macrophages, in which the affinity of PMB for lipid A plays an important role.

Animals ; Cytokines ; analysis ; Limulus Test ; Lipid A ; antagonists & inhibitors ; Lipopolysaccharides ; antagonists & inhibitors ; Macrophages ; chemistry ; Mice ; Polymyxin B ; pharmacology

Aptamers are oligonucleotides derived from an in vitro evolution process called SELEX (Systematic Evolution of Ligands by Exponential Enrichment). Aptamers specially binding to targets could recognize and inhibit the function of targets. Using this method, many powerful antagonists of cytokines have been found. In order for these antagonists to work in animal models of disease and in humans, it is necessary to modify the aptamers. First of all, 2'-F, 2'-NH2 and 2'-CH3O modifications of nucleoside triphosphates could prolong half-lives in blood. Aptamers can be kept in the circulation from hours to days by conjugating them to higher molecular weight vehicles. After modified, conjugated aptamers are injected into animals, they inhibit physiological functions known to be associated with their target cytokines. Exhibiting binding characteristics comparable to or even better than monoclonal antibodies, these ligands can be used as detection probes, highly efficient inhibitors of protein function or specific competitors in high-throughput screening (HTS) assays. Recently several aptamers of cytokines have been characterized. Some of them have been used as diagnostic agent for the detection of target cytokines. The first aptamer that has proceeded to phase II clinical studies is NX-1838, an injectable angiogenesis inhibitor that can be potentially used to treat macular degeneration-induced blindness. Aptamers will be versatile tools that can greatly enhance the efficiency of modern diagnose and therapy development.
Cytokines ; antagonists & inhibitors ; High-Throughput Screening Assays ; Humans ; Oligonucleotides ; therapeutic use ; SELEX Aptamer Technique ; Vascular Endothelial Growth Factor A ; antagonists & inhibitors

Toll-like receptors (TLRs) are pivotal components of the innate immune response, which is responsible for eradicating invading microorganisms through the induction of inflammatory molecules. These receptors are also involved in responding to harmful endogenous molecules and have crucial roles in the activation of the innate immune system and shaping the adaptive immune response. However, TLR signaling pathways must be tightly regulated because undue TLR stimulation may disrupt the fine balance between pro- and anti-inflammatory responses. Such disruptions may harm the host through the development of autoimmune and inflammatory diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Several studies have investigated the regulatory pathways of TLRs that are essential for modulating proinflammatory responses. These studies reported several pathways and molecules that act individually or in combination to regulate immune responses. In this review, we have summarized recent advancements in the elucidation of the negative regulation of TLR signaling. Moreover, this review covers the modulation of TLR signaling at multiple levels, including adaptor complex destabilization, phosphorylation and ubiquitin-mediated degradation of signal proteins, manipulation of other receptors, and transcriptional regulation. Lastly, synthetic inhibitors have also been briefly discussed to highlight negative regulatory approaches in the treatment of inflammatory diseases.
Animals ; Cytokines/biosynthesis ; Humans ; Ligands ; Models, Immunological ; Signal Transduction/*immunology ; Toll-Like Receptors/antagonists & inhibitors/*metabolism

The treatments for heart failure were developed rapidly in recent years ; new therapeutic techniques such as cytokine therapy, gene therapy and pacemaker therapy have been developed respectively. This paper reviews the mechanisms, therapeutic effect and limitation of these new techniques, and the future work in this research field is also discussed.
Cardiac Pacing, Artificial ; Combined Modality Therapy ; Cytokines ; antagonists & inhibitors ; Genetic Therapy ; Heart Failure ; therapy ; Humans

P2X7 receptor is a member of ATP-gated non-selective cation channels. P2X7 receptor is widely distributed in vivo, and its expression is always observed to be up-regulated in the pathological inflammatory circumstances. P2X7 receptor has an unusual property of forming membrane pore during prolonged agonist exposure or high concentrations of agonist activation, different from other members of P2X receptors (P2X1-6). Because of this property, P2X7 receptor has been implicated in inflammatory cytokine release, and is closely related to inflammatory diseases. With the wide application of the P2X7-knockout animal model and specific P2X7 receptor antagonists in inflammatory disease research, P2X7 receptor is emerging as a new target for the treatment of inflammatory diseases. This article will review the recent progress regarding the effect of P2X7 receptor on inflammatory diseases and its mechanism.
Animals ; Cytokines ; metabolism ; Disease Models, Animal ; Inflammation ; metabolism ; Purinergic P2X Receptor Antagonists ; pharmacology ; Receptors, Purinergic P2X7 ; metabolism

Antibodies, Anti-Idiotypic ; therapeutic use ; Antibodies, Monoclonal ; therapeutic use ; Antibodies, Monoclonal, Humanized ; Asthma ; drug therapy ; immunology ; Cytokines ; antagonists & inhibitors ; Humans ; Interleukin-5 ; antagonists & inhibitors ; Omalizumab ; Receptors, Interleukin-4 ; therapeutic use ; T-Lymphocytes ; physiology ; Tumor Necrosis Factor-alpha ; antagonists & inhibitors

To study the preventive effect of sophocarpine (Soc) on dextran sulfate sodium (DSS)-induced colitis in mice, in order to analyze the influence of Soc on toll like receptor 4 (TLR4)/mitogen-activated protein kinases (MAPKs) and janus tyrosine kinase 2 signal transducer and activator of transcription 3 (JAK2/STAT3) signal pathways in mice intestinal tissues. The mice was given 2.5% DSS for 6 days to induce the acute colitis model. The Soc-treated group was intraperitoneally injected with sophocarpine 30 mg · kg(-1) · d(-1) since the day before the experiment to the end. The disease activity index (DAI) was assessed everyday, and the colonic morphology and histological damage were observed with HE staining. The mRNA expressions of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were detected by real-time RT-PCR. The changes in key protein kinase p38 mitogen-activated protein kinase (p38MAPK), c-Jun NH2-terminal protein kinase1/2 (JNK1/2), extracellular signal-regulated kinase1/2 (ERK1/2), JAK2, STAT3 in TLR4/MAPKs and JAK2/STAT3 signaling pathways were detected by western blot. The result showed that the model group showed statistical significance in body weight, DAI, colon length and histopathological changes compared with the normal group (P <0.05); however, the Soc-treated group showed significant improvements in the above indexes compared with the model group (P <0.05). TNF-α, IL-1β and IL-6 in the model group was significantly higher than that in the normal group (P <0.05), but lowered in the Soc-treated group to varying degrees (P <0.05). In the normal group, the expressions of TLR4 and the phosphorylation of P38, JNK1/2, JAK2, STAT3 were at low levels; in the model group, the phosphorylation of P38, JNK1/2, JAK2, STAT3 increased; the Soc-treated group showed a decrease in TLR4 expression compared with the model group, with notable declines in the phosphorylation of TLR4, P38, JNK1/2, JAK2, STAT3. These findings indicate that Soc can inhibit TLR4/MAPKs, K2/STAT3 signaling pathway activation, reduce the expression of proinflammatory cytokines TNF-α, IL-1β and IL-6 and relieve inflammatory reactions, so as to effectively prevent experimental colitis.
Alkaloids ; pharmacology ; therapeutic use ; Animals ; Colitis ; drug therapy ; immunology ; pathology ; Cytokines ; genetics ; Janus Kinase 2 ; antagonists & inhibitors ; physiology ; Male ; Mice ; Mice, Inbred BALB C ; Phosphorylation ; STAT3 Transcription Factor ; antagonists & inhibitors ; physiology ; Toll-Like Receptor 4 ; antagonists & inhibitors ; physiology

Proteinuria is a cardinal manifestation of renal disease and has been proposed to promote progression of renal disease. Proteinuria develops in 9~41% of transplant recipients, and is diagnosed by routine urinalysis, urine protein to creatinine ratio, or 24-hour urine protein collection. Protein excretion of >200 mg/24 h is considered abnormal. The etiology of post-transplant proteinuria is diverse, including allograft rejection, recurrent or de novo glomerulonephritis, cyclosporine A nephrotoxicity, conversion to sirolimus, and chronic allograft nephropathy, which is the most common. Transplant renal biopsy is required to confirm the cause of proteinuria, and a combination of two or more of the transplant pathological categories can be present. High-grade proteinuria is believed to mediate progressive renal damage by conferring to proximal tubular epithelial cells with increased production of endothelin-1, chemokines such as monocyte chemoattractant protein-1 and cytokines, all of which promote interstitial fibrosis. It has been reported that proteinuria after renal transplantation affected not only graft survival but also patient survival. In proteinuric recipients, both the cardiovascular and noncardiovascular death risks seem to be significantly increased compared with nonproteinuric recipients. Low-grade (<1 g/24 h) proteinuria 1 year after transplantation is also associated with graft loss. The treatments for proteinuria are blood pressure control, and the use of angiotensin-converting enzyme inhibitor and/or angiotensin II receptor blockers therapy. Several options that are able to reduce proteinuia, including nondihydropyridine calcium channel blocker or aldosterone antagonists are also available. In conclusion, post-transplant proteinuria is a sensitive marker of graft dysfunction, correlated both to graft failure and to patient death. Appropriate management guided by proven cause and antiproteinuric treatments may improve the outcome.
Allografts ; Angiotensin Receptor Antagonists ; Biopsy ; Blood Pressure ; Calcium Channels ; Chemokine CCL2 ; Chemokines ; Creatinine ; Cyclosporine ; Cytokines ; Endothelin-1 ; Epithelial Cells ; Fibrosis ; Glomerulonephritis ; Graft Survival ; Humans ; Kidney Transplantation ; Mineralocorticoid Receptor Antagonists ; Proteinuria* ; Sirolimus ; Transplantation ; Transplants ; Urinalysis

OBJECTIVETo study the effect of total coumarins (TC) from Urtica dentata on dextran sulfate sodium (DSS)-induced colitis in mice.

METHODThe colitis model was established by administering DSS. Having been treated with TC, their body weight was determined. Concentrations of IL-6, IL-10, TGF-beta1 and IFN-gamma were monitored by ELISA. Colon samples were collected for the histopathological examination. Western blot was used to detect TLR4 and NF-kappaB protein expression in colonic tissues.

RESULTTCs from U. dentata effectively controlled the body weight loss of mice with colitis, down-regulated the concentration of IL-6 and IFN-gamma and increased the suppressive cytokines IL-10 and TGF-beta1 in the serum. Additionally, TC alleviated the mucosal damage and decreased the expressions of TLR4 and NF-kappaB in colonic tissues.

CONCLUSIONTCs from U. dentata shows the anti-inflammatory effect on colitis in mice by reducing the expressions of TLR4 and NF-kappaB in colonic tissues and regulating pro-and anti-inflammatory cytokines.

Animals ; Colitis ; drug therapy ; metabolism ; Coumarins ; therapeutic use ; Cytokines ; blood ; Dextran Sulfate ; toxicity ; Disease Models, Animal ; Male ; Mice ; Mice, Inbred BALB C ; NF-kappa B ; antagonists & inhibitors ; Toll-Like Receptor 4 ; antagonists & inhibitors ; Urticaceae ; chemistry

The aim of this study was to investigate the effect of suppression of nicotinamide phosphoribosyltransferase (NAMPT) expression on imatinib-sensitivity in chronic myelogenous leukemia (CML) cell line K562 and its mechanisms, NAMPT siRNA was synthesized and transfected into K562 cells. PI/Calcein staining technique was used to determine survival rate of transfected K562 cells at 48th hour after exposure to 1 µmol/L imatinib. MTS method was used to determine the proliferation changes of transfected K562 cell at 48th hour after exposure to different doses of imatinib, then half inhibitory concentration (IC(50)) was calculated. Expression of NAMPT at 3rd-48th hour after exposure to 1 µmol/L imatinib was determined by Western blot. To explore the effect of NAMPT-siRNA and imatinib on the expression of apoptosis-related genes, the microarray data from NCBI GEO Data-Sets was analyzed, then the results were confirmed by Western blot. The luciferase reporter assay was used to determine the effect of NAMPT and imatinib on transcriptional activity of NF-κB transcription factors. The results showed that after exposure to 1 µmol/L imatinib for 3 - 48 h, there was no significant change of NAMPT expression in K562 cells. The expression of NAMPT could be effectively inhibited by the NAMPT-siRNA. After exposure to 1 µmol/L of imatinib for 48 h, the survival rate of NAMPT-siRNA interference group was lower than that of negative control group (P < 0.05), indicating that suppression of NAMPT expression can increase the sensitivity of K562 cells to imatinib and enhance the killing effect of imatinib on K562 cells. The IC(50) of imatinib in NAMPT-siRNA interference group was the lowest compared with that of control group (P < 0.05) after exposure to different concentrations of imatinib for 48 h, the fitted survival curves showed that the slope of NAMPT-siRNA interference group was the largest ranging between 0.01 - 0.1 µmol/L of imatinib. Data mining of expression profiling indicated that the anti-apoptotic factor Bcl-2 decreased in K562 cells treated with either NAMPT-siRNA or imatinib, which was confirmed by Western blot. The inhibitory effect was much more significant when both NAMPT-siRNA and imatinib were used. The results of luciferase reporter assay showed that either NAMPT-siRNA or imatinib decreased transcriptional activity of NF-κB. The decreased effect was much more significant when both NAMPT-siRNA and imatinib were used. It is concluded that survival of K562 cells affected by imatinib may not be due to regulation of expression of NAMPT. When expression of NAMPT decreases, the K562 cells are more sensitive to imatinib, this may be related with the decreased transcriptional activity of NF-κB and its downstream effector Bcl-2.
Benzamides ; Cytokines ; antagonists & inhibitors ; metabolism ; Fusion Proteins, bcr-abl ; metabolism ; Humans ; Imatinib Mesylate ; K562 Cells ; NF-kappa B ; metabolism ; Nicotinamide Phosphoribosyltransferase ; antagonists & inhibitors ; metabolism ; Piperazines ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Pyrimidines ; pharmacology