Tumor necrosis factor-stimulated gene-6 ameliorates early brain injury after subarachnoid hemorrhage by suppressing NLRC4 inflammasome-mediated astrocyte pyroptosis

Subarachnoid hemorrhage is associated with high morbidity and mortality and lacks effective treatment.Pyroptosis is a crucial mechanism underlying early brain injury after subarachnoid hemorrhage.Previous studies have confirmed that tumor necrosis factor-stimulated gene-6(TSG-6)can exert a neuroprotective effect by suppressing oxidative stress and apoptosis.However,no study to date has explored whether TSG-6 can alleviate pyroptosis in early brain injury after subarachnoid hemorrhage.In this study,a C57BL/6J mouse model of subarachnoid hemorrhage was established using the endovascular perforation method.Our results indicated that TSG-6 expression was predominantly detected in astrocytes,along with NLRC4 and gasdermin-D(GSDMD).The expression of NLRC4,GSDMD and its N-terminal domain(GSDMD-N),and cleaved caspase-1 was significantly enhanced after subarachnoid hemorrhage and accompanied by brain edema and neurological impairment.To explore how TSG-6 affects pyroptosis during early brain injury after subarachnoid hemorrhage,recombinant human TSG-6 or a siRNA targeting TSG-6 was injected into the cerebral ventricles.Exogenous TSG-6 administration downregulated the expression of NLRC4 and pyroptosis-associated proteins and alleviated brain edema and neurological deficits.Moreover,TSG-6 knockdown further increased the expression of NLRC4,which was accompanied by more severe astrocyte pyroptosis.In summary,our study revealed that TSG-6 provides neuroprotection against early brain injury after subarachnoid hemorrhage by suppressing NLRC4 inflammasome activation-induced astrocyte pyroptosis.

Analyze interleukin-1β,interleukin-6,and tumor necrosis factor-αlevels in dry eye and the therapeutic effect of cyclosporine A

BACKGROUND Dry eye is a common eye disease.Artificial tears supplements are widely used for the treatment of dry eyes.However,multiple adverse effects have been observed in patients receiving long-term treatment with artificial tears,which may affect the therapeutic effect.AIM To analyze the characteristics of interleukin-1β(IL-1β),interleukin-6(IL-6),and tumor necrosis factor-alpha(TNF-α)levels in patients with dry eye and the therapeutic effect of artificial tears combined with cyclosporine A.METHODS A total of 124 dry eye patients treated at The First People’s Hospital of Xining from April 2020 to April 2022 were selected as the observation group,while 20 healthy individuals served as the control group during the same period.Levels of inflammatory markers,including IL-1β,IL-6,and TNF-α,were analyzed.The observation group was further divided into a study group and a control group,each consisting of 62 patients.The control group received artificial tears,whereas the study group received a combination of artificial tears and cyclosporine A.Inflammatory markers,Schirmer’s test(SIT),tear break-up time(TBUT),corneal fluorescein staining(CFS),National Eye Institute Visual Function Questionnaire-25(NEI-VFQ-25)scores,and adverse events(AEs)were compared between the two groups.RESULTS The observation group exhibited significantly elevated serum levels of IL-1β,IL-6,and TNF-αin comparison to the healthy group.Following treatment,the study group demonstrated substantial reductions in IL-1β,IL-6,and TNF-αlevels relative to the control group.Moreover,after treatment,the study group experienced a marked decrease in CFS scores and significant increases in both SIT and BUT levels when compared to the control group.Additionally,significant improvements were observed in the primary symptom of dry eye and secondary symptoms such as photophobia,foreign body sensation,fatigue,red eye,and burning sensation within the study group.Furthermore,post-treatment NEI-VFQ-25 scores across all dimensions exhibited significant enhancements in the study group compared to the control group(P<0.05).It is noteworthy that significant AEs were reported in both groups throughout the treatment period.CONCLUSION Cyclosporine A combined with artificial tears is effective in treating dry eye,yielding enhanced outcomes by improving SIT and TBUT levels,reducing CFS scores,and ameliorating vision-related quality of life.

The action mechanism by which C1q/tumor necrosis factor-related protein-6 alleviates cerebral ischemia/reperfusion injury in diabetic mice

Studies have shown that C1q/tumor necrosis factor-related protein-6 (CTRP6) can alleviate renal ischemia/reperfusion injury in mice. However, its role in the brain remains poorly understood. To investigate the role of CTRP6 in cerebral ischemia/reperfusion injury associated with diabetes mellitus, a diabetes mellitus mouse model of cerebral ischemia/reperfusion injury was established by occlusion of the middle cerebral artery. To overexpress CTRP6 in the brain, an adeno-associated virus carrying CTRP6 was injected into the lateral ventricle. The result was that oxygen injury and inflammation in brain tissue were clearly attenuated, and the number of neurons was greatly reduced. In vitro experiments showed that CTRP6 knockout exacerbated oxidative damage, inflammatory reaction, and apoptosis in cerebral cortical neurons in high glucose hypoxia-simulated diabetic cerebral ischemia/reperfusion injury. CTRP6 overexpression enhanced the sirtuin-1 signaling pathway in diabetic brains after ischemia/reperfusion injury. To investigate the mechanism underlying these effects, we examined mice with depletion of brain tissue-specific sirtuin-1. CTRP6-like protection was achieved by activating the sirtuin-1 signaling pathway. Taken together, these results indicate that CTRP6 likely attenuates cerebral ischemia/reperfusion injury through activation of the sirtuin-1 signaling pathway.

Efficacy of Laparoscopic Cholecystectomy in Treating Patients with Gallstones and Its Effect on Interleukin-6 and Tumor Necrosis Factor-α Levels

Objective:To investigate the efficacy of laparoscopic cholecystectomy in the treatment of patients with gallstones and its effect on the levels of interleukin-6(IL-6)and tumor necrosis factor-α(TNF-a).Methods:A total of 82 patients with gallstones admitted from July 2020 to July 2023 were recruited and allocated into control and observation groups using the random number table method,with 41 cases in each group.The patients were treated with laparoscopic cholecystectomy,with the anterior triangle anatomical approach to the gallbladder in the control group and the posterior triangle anatomical approach to the gallbladder in the observation group.The treatment effect and inflammatory factor levels of both groups were observed and compared.Results:When comparing the clinical outcomes of both patient groups,the key parameters evaluated included time to mobilization,duration of surgery,extubation time,and intraoperative bleeding.The observation group exhibited a significant advantage in these parameters compared to the control group(P<0.05).Regarding the levels of inflammatory factors between the two groups before and after treatment,there was no significant difference in values before treatment.However,following treatment,patients in the observation group showed significantly lower levels of IL-6,TNF-α,and C-reactive protein(CRP)compared to the control group(P<0.05).Conclusion:Patients undergoing laparoscopic cholecystectomy for gallstones can benefit from the implementation of the posterior triangular anatomical approach to the gallbladder,which not only enhances therapeutic efficacy but also offers significant advantages in reducing levels of IL-6,TNF-α,and CRP.Therefore,it is recommended for the widespread adoption of this treatment approach in clinical practice.

Interferon-gamma and tumor necrosis factor-alpha synergistically enhance the immunosuppressive capacity of human umbilical-cordderived mesenchymal stem cells by increasing PD-L1 expression

BACKGROUND The immunosuppressive capacity of mesenchymal stem cells(MSCs)is dependent on the“license”of several proinflammatory factors to express immunosuppressive factors such as programmed cell death 1 ligand 1(PD-L1),which determines the clinical therapeutic efficacy of MSCs for inflammatory or immune diseases.In MSCs,interferon-gamma(IFN-γ)is a key inducer of PD-L1 expression,which is synergistically enhanced by tumor necrosis factor-alpha(TNF-α);however,the underlying mechanism is unclear.AIM To reveal the mechanism of pretreated MSCs express high PD-L1 and explore the application of pretreated MSCs in ulcerative colitis.METHODS We assessed PD-L1 expression in human umbilical-cord-derived MSCs(hUC-MSCs)induced by IFN-γand TNF-α,alone or in combination.Additionally,we performed signal pathway inhibitor experiments as well as RNA interference experiments to elucidate the molecular mechanism by which IFN-γalone or in combination with TNF-αinduces PD-L1 expression.Moreover,we used luciferase reporter gene experiments to verify the binding sites of the transcription factors of each signal transduction pathway to the targeted gene promoters.Finally,we evaluated the immunosuppressive capacity of hUC-MSCs treated with IFN-γand TNF-αin both an in vitro mixed lymphocyte culture assay,and in vivo in mice with dextran sulfate sodium-induced acute colitis.RESULTS Our results suggest that IFN-γinduction alone upregulates PD-L1 expression in hUC-MSCs while TNF-αalone does not,and that the co-induction of IFN-γand TNF-αpromotes higher expression of PD-L1.IFN-γinduces hUCMSCs to express PD-L1,in which IFN-γactivates the JAK/STAT1 signaling pathway,up-regulates the expression of the interferon regulatory factor 1(IRF1)transcription factor,promotes the binding of IRF1 and the PD-L1 gene promoter,and finally promotes PD-L1 mRNA.Although TNF-αalone did not induce PD-L1 expression in hUCMSCs,the addition of TNF-αsignificantly enhanced IFN-γ-induced JAK/STAT1/IRF1 activation.TNF-αupregulated IFN-γreceptor expression through activation of the nuclear factor kappa-B signaling pathway,which significantly enhanced IFN-γsignaling.Finally,co-induced hUC-MSCs have a stronger inhibitory effect on lymphocyte proliferation,and significantly ameliorate weight loss,mucosal damage,inflammatory cell infiltration,and up-regulation of inflammatory factors in colitis mice.CONCLUSION Overall,our results suggest that IFN-γand TNF-αenhance both the immunosuppressive ability of hUC-MSCs and their efficacy in ulcerative colitis by synergistically inducing high expression of PD-L1.

Tumor Necrosis Factor-Alpha (TNF)-308G/A and Interleukin 8(IL-8)-251C/T Polymorphisms in Pulmonary Tuberculosis Patients from Congo

Background: Tuberculosis (TB) is one of the world’s deadliest infectious diseases. Tumor necrosis factor-Alpha (TNF-α) and Interleukin 8 (IL-8) are involved in the pathogenesis of pulmonary TB (PTB). However, the contribution of polymorphisms of these cytokines to PTB susceptibility needed more investigation across geographic regions and ethnic groups. Purpose: The aim of this study was to investigate the association of the TNF-α-308 G/A and IL-8-251T/A polymorphisms with PTB risk in the Congolese population. Methods: This case-control study included 150 PTB patients and 160 control subjects. Blood samples were collected from all participants and were used for the TNF-α-308 G/A and IL-8-251T/A genotyping by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Odds ratios (OR) were calculated to estimate the potential polymorphism associations. A P level of Results: A significant difference was found between PTB patients and controls regarding the TNF-α-308AA genotype (P = 0.035) distribution. Moreover, this genotype was associated with risk to TB (OR = 7.19, 95% CI = 0.85 - 60.65, P = 0.035). The A allele was significantly more frequent in PTB patients than in controls, and was associated with risk to PTB (OR = 1.68, 95% CI = 1.05 - 2.68, P = 0.014). Regarding the IL-8-251T/A gene, TA and AA genotypes were significantly more frequent in PTB patients compared to controls, and were associated with increased risk to PTB (OR = 2.64, 95% CI = 0.97 - 7.18, P = 0.031 and OR = 3.0, 95% CI = 1.13 - 7.98, P = 0.014, respectively). However, the IL-8-251 A allele was not associated to PTB susceptibility (OR = 0.27, 95% CI = 0.15 - 0.44). Conclusion: TNF-α-308G/A and IL-8-251T/A polymorphisms may be associated to PTB susceptibility in the Congolese population, and the AA genotype of both cytokines could be a risk factor.

Correlation of tumor necrosis factor-β and interleukin-1 gene cluster polymorphism with susceptibility to bacteremia in patients undergoing kidney transplantation

Background Bacteremia remains a significant cause of morbidity and mortality after kidney transplantation. This study was conducted to investigate whether the polymorphisms of tumor necrosis factor （TNF）-β, interleukin （IL）-1β, and IL-1 receptor antagonist （IL-lra） gene predicted the susceptibility to bacteremia within the first 6 months after kidney transplantation. Methods Subjects comprised 82 infected kidney transplant recipients and 60 non-infected kidney transplant recipients. Bacteremia was diagnosed in 16 of the 82 infected recipients. Genomic DNA from these 142 kidney transplant recipients was extracted from peripheral blood leukocytes. Regions containing the Ncol polymorphic site at position ＋252 of TNF-β gene and the Aval polymorphic site at position -511 of IL-Iβ gene were amplified by polymerase chain reaction （PCR） and subsequently digested with Ncol and Aval restriction enzymes, respectively. The polymorphic regions within intron 2 of IL-lra gene containing variable numbers of a tandem repeat （VNTR） of 86 base pairs were amplified by PCR. Results Genotypic and allelic frequencies were similar between infected recipients and non-infected ones. Individual locus analysis showed that recipient TNF-β and IL-lra gene polymorphisms were not associated with the presence of bacteremia （P=0.684 and P=0.567, respectively）. However, genotype analysis revealed that recipient IL-1β 511CC genotype was strongly associated with susceptibility to develop bacteremia （P=0.003）. Recipient IL-1β-511CC genotype （odds ratio 5.242, 95% confidence intervals 1.645-16.706, P=0.005） independently predicted the risk for bacteremia within the first 6 months after kidney transplantation. Conclusions These findings indicate a critical role of IL-1β gene polymorphisms in susceptibility to bacteremia after kidney transplantation, which may be useful to screen for patients at higher risk for post-transplant bacteremias. Thus, the identified individuals can benefit from preventive treatment and a less potent immunosuppressive regimen.

Study of tumor necrosis factor receptor in the inflammatory bowel disease

Ulcerative colitis(UC)and Crohn’s disease(CD)are part of Inflammatory Bowel Diseases(IBD)and have pathophysiological processes such as bowel necrosis and enteric neurons and enteric glial cells.In addition,the main inflammatory mediator is related to the tumor necrosis factor-alpha(TNF-α).TNF-αis a mediator of the intestinal inflammatory processes,thus being one of the main cytokines involved in the pathogenesis of IBD,however,its levels,when measured,are present in the serum of patients with IBD.In addition,TNF-αplays an important role in promoting inflammation,such as the production of interleukins(IL),for instance IL-1βand IL-6.There are two receptors for TNF as following:The tumor necrosis factor 1 receptor(TNFR1);and the tumor necrosis factor 2 receptor(TNFR2).They are involved in the pathogenesis of IBD and their receptors have been detected in IBD and their expression is correlated with disease activity.The soluble TNF form binds to the TNFR1 receptor with,and its activation results in a signaling cascade effects such as apoptosis,cell proliferation and cytokine secretion.In contrast,the transmembrane TNF form can bind both to TNFR1 and TNFR2.Recent studies have suggested that TNF-αis one of the main pro-inflammatory cytokines involved in the pathogenesis of IBD,since TNF levels are present in the serum of both patients with UC and CD.Intravenous and subcutaneous biologics targeting TNF-αhave revolutionized the treatment of IBD,thus becoming the best available agents to induce and maintain IBD remission.The application of antibodies aimed at neutralizing TNF-αin patients with IBD that induce a satisfactory clinical response in up to 60%of patients,and also induced long-term maintenance of disease remission in most patients.It has been suggested that anti-TNF-αagents inactivate the pro-inflammatory cytokine TNF-αby direct neutralization,i.e.,resulting in suppression of inflammation.However,anti-TNF-αantibodies perform more complex functions than a simple blockade.

Predictors and optimal management of tumor necrosis factor antagonist nonresponse in inflammatory bowel disease:A literature review

Tumor necrosis factor-α(TNF-α)antagonists,the first biologics approved for treating patients with inflammatory bowel disease(IBD),are effective for the induction and maintenance of remission and significantly improving prognosis.However,up to one-third of treated patients show primary nonresponse(PNR)to anti-TNF-αtherapies,and 23%-50%of IBD patients experience loss of response(LOR)to these biologics during subsequent treatment.There is still no recognized predictor for evaluating the efficacy of anti-TNF drugs.This review summarizes the existing predictors of PNR and LOR to anti-TNF in IBD patients.Most predictors remain controversial,and only previous surgical history,disease manifestations,drug concentrations,antidrug antibodies,serum albumin,some biologic markers,and some genetic markers may be potentially predictive.In addition,we also discuss the next steps of treatment for patients with PNR or LOR to TNF antagonists.Therapeutic drug monitoring plays an important role in treatment selection.Dose escalation,combination therapy,switching to a different anti-TNF drug,or switching to a biologic with a different mechanism of action can be selected based on the concentration of the drug and/or antidrug antibodies.

Joint Detection of Serum Vitamin D,Body Mass Index,and Tumor Necrosis Factor Alpha for the Diagnosis of Crohn’s Disease

Objective Vitamin D(VD)deficiency was reported to contribute to the progression of Crohn’s disease(CD)and affect the prognosis of CD patients.This study investigated the role of serum VD,body mass index(BMI),and tumor necrosis factor alpha(TNF-α)in the diagnosis of Crohn’s disease.Methods CD patients(n=76)and healthy subjects(n=76)were enrolled between May 2019 and December 2020.The serum 25-hydroxyvitamin D[25(OH)D]levels,BMI,and TNF-αlevels,together with other biochemical parameters,were assessed before treatment.The diagnostic efficacy of the single and joint detection of serum 25(OH)D,BMI,and TNF-αwas determined using receiver operating characteristic(ROC)curves.Results The levels of 25(OH)D,BMI,and nutritional indicators,including hemoglobin,total protein,albumin,and high-density lipoprotein cholesterol,were much lower,and the TNF-αlevels were much higher in the CD patients than in the healthy subjects(P<0.05 for all).The areas under the ROC curve for the single detection of 25(OH)D,BMI,and TNF-αwere 0.887,0.896,and 0.838,respectively,with the optimal cutoff values being 20.64 ng/mL,19.77 kg/m^(2),and 6.85 fmol/mL,respectively.The diagnostic efficacy of the joint detection of 25(OH)D,BMI,and TNF-αwas the highest,with an area under the ROC curve of 0.988(95%CI:0.968–1.000).Conclusion The joint detection of 25(OH)D,TNF-α,and BMI showed high sensitivity,specificity,and accuracy in CD diagnosis;thus,it would be effective for the diagnosis of CD in clinical practice.

Acute heart failure as an adverse event of tumor necrosis factor inhibitor therapy in inflammatory bowel disease:A review of the literature

Tumor necrosis factor inhibitors(anti-TNFs)are widely used therapies for the treatment of inflammatory bowel diseases(IBD);however,their administration is not risk-free.Heart failure(HF),although rare,is a potential adverse event related to administration of these medications.However,the exact mechanism of development of HF remains obscure.TNFαis found in both healthy and damaged hearts.Its effects are concentration-and receptor-dependent,promoting either cardio-protection or cardiomyocyte apoptosis.Experimental rat models with TNFαreceptor knockout showed increased survival rates,less reactive oxygen species formation,and improved diastolic left ventricle pressure.However,clinical trials employing anti-TNF therapy to treat HF had disappointing results,suggesting abolishment of the cardioprotective properties of TNFα,making cardiomyocytes susceptible to apoptosis and oxidation.Thus,patients with IBD who have risk factors should be screened for HF before initiating anti-TNF therapy.This review aims to discuss adverse events associated with the administration of anti-TNF therapy,with a focus on HF,and propose some approaches to avoid cardiac adverse events in patients with IBD.

Effects of β-Aescin on the expression of nuclear factor-κB and tumor necrosis factor-α after traumatic brain injury in rats

To investigate the inhibiting effect of β-Aescin on nuclear factor-κB (NF-κB) activation and the expression of tumor necrosis factor-α (TNF-α) protein after traumatic brain injury (TBI) in the rat brain, 62 SD rats were subjected to lateral cortical impact injury caused by a free-falling object and divided randomly into four groups: (1) sham operated (Group A); (2) injured (Group B); (3) β-Aescin treatment (Group C); (4) pyrrolidine dithocarbamate (PDTC) treatment (Group D). β-Aescin was administered in Group C and PDTC treated in Group D immediately after injury. A series of brain samples were obtained directly 6h, 24 h and 3 d respectively after trauma in four groups. NF-κB activation was examined by Electrophoretic Mobility Shift Assay (EMSA); the levels of TNF-α protein were measured by radio-immunoassay (RIA); the water content of rat brain was measured and pathomorphological observation was carried out. NF-κB activation, the levels of TNF-α protein and the water content of rat brain were significantly increased (P＜0.01) following TBI in rats. Compared with Group B, NF-κB activation (P＜0.01), the levels of TNF-α protein (P＜0.01) and the water content of brain (P＜0.05) began to decrease obviously after injury in Groups C and D.β-Aescin could dramatically inhibit NF-κB activation and the expression of TNF-α protein in the rat brain, alleviate rat brain edema, and that could partially be the molecular mechanism by which β-Aescin attenuates traumatic brain edema.

Changes of Tumor Necrosis Factor-α and the Effects of Ulinastatin Injection during Cardiopulmonary Cerebral Resuscitation

Summary: The changes of tumor necrosis factor-α (TNF-α) and brain ultrastructure during cardiopulmonary resuscitation and the effects of ulinastation injection were observed, and the mechanism was investigated. Twenty-four adult healthy Sprague-Dawley rats were randomly divided into control group (8 rats), resuscitation group (8 rats) and ulinastatin (UTI) group (8 rats). Rats in control group underwent tracheotomy without clipping the trachea to induce circulatory and respiratory standstill. Rats in resuscitation and ulinastatin group were subjected to the procedure of establishing the model of cardiopulmonary cerebral resuscitation (CPCR). Rats in ulinastatin group were given with UTI 104 U/kg once after CPCR. In the control group, the plasma was collected immediate, 30 min, 2 h, 4 h, and 6 h after tracheotomy. In resuscitation group and UTI group, plasma was collected immediate after tracheotomy, 30 min, 2 h, 4 h and 6 h after successful resuscitation. The plasma levels of TNF-α were determined by radioimmunoassay (RIA). At the end of the experiment, 2 rats were randomly selected from each group and were decapitated. The cortex of the brain was taken out immediately to observe the ultrastructure changes. In control group, there were no significant differences in the level of TNF-α among different time points (P>0.05). In resuscitation group, the level of TNF-α was increased obviously after resuscitation (P<0.01) and reached its peak 2 h later after resuscitation. An increasing trend of TNF-α showed in UTI group. There were no differences in TNF-α among each sample taken after successful resuscitation and that after tracheotomy. The utrastructure of brains showed the injury in UTI group was ameliorated as compared with that in resuscitation group. In early period of CPCR, TNF-α was expressed rapidly and kept increasing. It indicated that TNF-α might take part in the tissue injury after CPCR. The administration of UTI during CACR could depress TNF-α and ameliorate brain injury. By regulating the expression of damaging mediator, UTI might provide a protective effect on the tissue injury after CPCR.

Quercetin exerts anti-inflammatory effects via inhibiting tumor necrosis factor-α-induced matrix metalloproteinase-9 expression in normal human gastric epithelial cells

BACKGROUND Gastric injury is the most common digestive system disease worldwide and involves inflammation,which can lead to gastric ulcer or gastric cancer(GC).Matrix metallopeptidase-9[MMP-9(gelatinase-B)]plays an important role in inflammation and GC progression.Quercetin and quercetin-rich diets represent potential food supplements and a source of medications for treating gastric injury given their anti-inflammatory activities.However,the effects and mechanisms of action of quercetin on human chronic gastritis and whether quercetin can relieve symptoms remain unclear.AIM To assess whether tumor necrosis factor-α(TNF-α)-induced MMP-9 expression mediates the anti-inflammatory effects of quercetin in normal human gastric mucosal epithelial cells.METHODS The normal human gastric mucosa epithelial cell line GES-1 was used to establish a normal human gastric epithelial cell model of TNF-α-induced MMP-9 protein overexpression to evaluate the antiinflammatory effects of quercetin.The cell counting Kit-8 assay was used to evaluate the effects of varying quercetin doses on cell viability in the normal GES-1 cell line.Cell migration was measured using Transwell assay.The expression of proto-oncogene tyrosine-protein kinase Src(cSrc),phospho(p)-c-Src,extracellular-signal-regulated kinase 2(ERK2),p-ERK1/2,c-Fos,p-c-Fos,nuclear factor kappa B(NF-κB/p65),and p-p65 and the effects of their inhibitors were examined using Western blot analysis and measurement of luciferase activity.p65 expression was detected by immunofluorescence.MMP-9 m RNA and protein levels were measured by quantitative reverse transcription polymerase chain reaction(q RT–PCR)and gelatin zymography,respectively.RESULTS q RT-PCR and gelatin zymography showed that TNF-αinduced MMP-9 m RNA and protein expression in a dose-and time-dependent manner.These effects were reduced by the pretreatment of GES-1 cells with quercetin or a TNF-αantagonist(TNFR inhibitor)in a dose-and timedependent manner.Quercetin and TNF-αantagonists decreased the TNF-α-induced phosphorylation of c-Src,ERK1/2,c-Fos,and p65 in a dose-and time-dependent manner.Quercetin,TNF-αantagonist,PP1,U0126,and tanshinone IIA(TSIIA)reduced TNF-α-induced c-Fos phosphorylation and AP-1–Luciferase(Luc)activity in a dose-and time-dependent manner.Pretreatment with quercetin,TNF-αantagonist,PP1,U0126,or Bay 11-7082 reduced TNF-α-induced p65 phosphorylation and translocation and p65–Luc activity in a dose-and timedependent manner.TNF-αsignificantly increased GES-1 cell migration,and these results were reduced by pretreatment with quercetin or a TNF-αantagonist.CONCLUSION Quercetin significantly downregulates TNF-α-induced MMP-9 expression in GES-1 cells via the TNFR-c-Src–ERK1/2 and c-Fos or NF-κB pathways.

Hepatitis B virus X protein up-regulates tumor necrosis factor-α expression in cultured mesangial cells via ERKs and NF-κB pathways

Objective:To investigate the effects of hepatitis B virus(HBV)X protein(HBx)on the expression of tumor necrosis factor-α(TNF-α)in glomerular mesangial cells(GMCs)and the underlying intracellular signal pathways.Methods:The plasmid pCI-neo-X that carries the X gene of hepatitis B virus was transfected into cultured GMCs.HBx expression in the transfected GMCs was assessed by Western-blot.TNF-αprotein and mRNA were assessed by ELISA and semi-quantitative RT-PCR,respectively.Three kinase inhibitors-U0126,an inhibitor of extracellular signal-regulated kinases(ERKs);lactacvstin,an inhibitor of nuclear factor-κB(NF-κB);and SB203580,a selective inhibitor of p38 MAP kinase(p38 MAPK)were used to determine which intracellular signal pathways may underlie the action of HBx on TNF-αexpression in transfected GMCs.Results:A significant increase in HBx expression in pCI-neo-X transfected GMCs was detected at 36 h and 48 h,which was not affected by any of those kinase inhibitors mentioned above.A similar increase in the expression of both TNF-αprotein and mRNA was also observed at 36 h and 48 h,which was significantly decreased in the presence of U0126 or lactacytin,but not SB203580.Conclusions:HBx upregulates TNF-αexpression in cultured GMCs,possibly through ERKs and NF-κB pathway,but not p38 MAPK pathway.

Expression of matrix metalloproteinase-1 and tumor necrosis factor-α in ulcerative colitis

AIM： To examine the expression of matrix metalloproteinase-1 （MMP-1） and tumor necrosis factor-α （TNF-~~） in the colon mucosa of patients with ulcerative colitis （UC）.METHODS： Reverse transcription-polymerase chain reaction （RT-PCR） and immunohistochemistry were used to examine the expression of MMP-1 and TNF-α at both mRNA and protein levels in the colon mucosa of patients with UC. Correlation between MMP-1 and TNF-α and their correlation with the severity of the disease were also analyzed statistically.RESULTS： The expression of MMP-1 and TNF-α in the ulcerated and inflamed colon mucosa of patients with UC was significantly higher than that in the non-inflamed mucosa of normal controls at both mRNA and protein levels. Furthermore, the expression of MMP-1 and TNF-α in the ulcerated area was significantly higher than that in the inflamed area of patients with UC （0.9797 ± 0.1433 vs 0.6746 ± 0.0373, 0.8669 ± 0.0746 vs 0.5227 ± 0.0435, P 〈 0.05）. There was no statistically significant difference in the non-inflamed area of normal controls. There was a significant correlation between MMP-1 and TNF-c~ expression （0.9797 ± 0.1433 vs 0.8669 ± 0.0746, P 〈 0.05）, the correlating factor was 0.877. MMP-1 and TNF-α showed a significant correlation with the severity of the disease （0.0915 ：e 0.0044 vs 0.0749 vs 0.0032, 0.0932 ± 0.0019 vs 0.0724 ± 0.0043, P 〈 0.05）, their correlating factors were 0.942 and 0.890, respectively.CONCLUSION： Excessively expressed MMP-1 directly damages the colon mucosa by degrading extracellular matrix （ECM） in patients with UC. While damaging colon mucosa, excessively expressed TNF-α stimulates MMPs secreting cells to produce more MMP-1 and aggravates the mucosa damage. MMP-1 promotes secretion of TNF-α in a positive feedback manner to cause further injury in the colon mucosa. MMP-1 and TNF-α correlate well with the severity of the disease, and therefore, can be used clinically as biological markers to judge the severity of UC.

EFFECT OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ACTIVATORS ON TUMOR NECROSIS FACTOR-αEXPRESSION IN NEONATAL RAT CARDIAC MYOCYTES

Objective To investigate the effect of peroxisome proliferator-activated receptor-α(PPARα) and PPARγactivators on tumor necrosis factor-α(TNFα) expression in neonatal rat cardiac myocytes. Methods Primary cultures of cardiac myocytes from 1- to 3-day-old Wistar rats were prepared, and myocytes were ex-posed to lipopolysaccharide (LPS) and varying concentrations of PPARαor PPARγactivator (fenofibrate or pioglitazone).RT-PCR and ELISA were used to measure TNFα, PPARα, and PPARγexpression in cultured cardiac myocytes. Transient tr-ansfection of TNFαpromoter with or without nuclear factor-kappaB (NF-κB) binding site to cardiac myocytes was performed. Results Pretreatment of cardiac myocytes with fenofibrate or pioglitazone inhibited LPS-induced TNFαmRNA and protein expression in a dose-dependent manner. However, no significant changes were observed on PPARαor PPARγmRNA expression when cardiac myocytes were pretreated with fenofibrate or pioglitazone. Proportional suppression of TNFαpromoter activity was observed when myocytes was transiently transfected with whole length of TNFαpromoter (-721/+17) after being stimulated with LPS and fenofibrate or pioglitazone, whereas no change of promoter activity was observed with transfection of TNFαreporter construct in deletion of NF-κB binding site (-182/+17). Conclusions PPARαand PPARγactivators may inhibit cardiac TNFαexpression but not accompanied by change of PPARαor PPARγmRNA expression. Therefore PPARαand PPARγactivators appear to play a role in anti-inflammation. The mechanism may partly be involved in suppression of the NF-κB pathway.

Tumor necrosis factor-α inhibitor therapy and fetal risk:A systematic literature review

Tumor necrosis factor-α inhibitors (anti-TNFs) are effective in the treatment of inflammatory bowel disease (IBD) recalcitrant to conventional medical therapy. As the peak incidence of IBD overlaps with the prime reproductive years, it is crucial to establish pharmacologic regimens for women of childbearing age that achieve effective disease control without posing significant fetal harm. A systematic literature review was performed to identify all human studies with birth outcomes data after maternal exposure to infliximab, adalimumab, or certolizumab pegol within 3 mo of conception or during any trimester of pregnancy. Live births, spontaneous abortions or stillbirths, preterm or premature births, low birth weight or small for gestational age infants, and congenital abnormalities were recorded. Fifty selected references identified 472 pregnancy exposures. The subsequent review includes general information regarding anti-TNF therapy in pregnancy followed by a summary of our findings. The benefits of biologic modalities in optimizing disease control during pregnancy must be weighed against the potential toxicity of drug exposure on the developing fetus. Although promising overall, there is insufficient evidence to prove absolute safety for use of anti-TNFs during pregnancy given the limitations of available data and lack of controlled trials.

Helicobacter pylori tumor necrosis factor-α inducing protein promotes cytokine expression via nuclear factor-κB

AIM:To study the effects of Helicobacter pylori(H. pylori)tumor necrosis factor-α(TNF)inducing protein (Tip-α)on cytokine expression and its mechanism. METHODS:We cloned Tip-αfrom the H.pylori strain 26695,transformed Escherichia coli with an expression plasmid,and then confirmed the expression product by Western blotting.Using different concentrations of Tip-αthat affected SGC7901 and GES-1 cells at different times,we assessed cytokine levels using enzyme-linked immunosorbent assay.We blocked SGC7901 cells with pyrrolidine dithiocarbamate(PDTC),a specific inhibitor of nuclear factorκB(NF-κB).We then detected interleukin(IL)-1βand TNF-αlevels in SGC7901 cells. RESULTS:Western blot analysis using an anti-Tip-α antibody revealed a 23-kDa protein,which indicated that recombinant Tip-αprotein was recombined successfully.The levels of IL-1β,IL-8 and TNF-αwere sig-nificantly higher following Tip-αinterference,whether GES-1 cells or SGC-7901 cells were used(P<0.05).However,the levels of cytokines(including IL-1β,IL-8 and TNF-α)secreted by SGC-7901 cells were greater than those secreted by GES-1 cells following treatment with Tip-αat the same concentration and for the same duration(P<0.05).After blocking NF-κB with PDTC, the cells(GES-1 cells and SGC-7901 cells)underwent interference with Tip-α.We found that IL-1βand TNF-αlevels were significantly decreased compared to cells that only underwent Tip-αinterference(P<0.05). CONCLUSION:Tip-αplays an important role in cyto-kine expression through NF-κB.

Tumor necrosis factor-α mediates JNK activation response to intestinal ischemia-reperfusion injury

AIM:To investigate whether tumor necrosis factor-α(TNF-α)mediates ischemia-reperfusion(I/R)-induced intestinal mucosal injury through c-Jun N-terminal kinase(JNK)activation.METHODS:In this study,intestinal I/R was induced by 60-min occlusion of the superior mesenteric artery in rats followed by 60-min reperfusion,and the rats were pretreated with a TNF-α inhibitor,pentoxifylline,or the TNF-α antibody infliximab.After surgery,part of the intestine was collected for histological analysis.The mucosal layer was harvested for RNA and protein extraction,which were used for further real-time polymerase chain reaction,enzyme-linked immunosorbent assay and Western blotting analyses.The TNF-α expression,intestinal mucosal injury,cell apoptosis,activation of apoptotic protein and JNK signaling pathway were analyzed.RESULTS:I/R significantly enhanced expression of mucosal TNF-α at both the mRNA and protein levels,induced severe mucosal injury and cell apoptosis,activated caspase-9/caspase-3,and activated the JNK signaling pathway.Pretreatment with pentoxifylline markedly downregulated TNF-α at both the mRNA and protein levels,whereas infliximab pretreatment did not affect the expression of TNF-α induced by I/R.However,pretreatment with pentoxifylline or infliximab dramatically suppressed I/R-induced mucosal injury and cell apoptosis and significantly inhibited the activation of caspase-9/3 and JNK signaling.CONCLUSION:The results indicate there was a TNFα-mediated JNK activation response to intestinal I/R injury.