Natural human IgG inhibits the production of tumor necrosis factor-α and interleukin-1α through the Fc portion

The overproduction of cytokines such as the tumor necrosis factor- (TNF-) and interleukin-1 (IL-1) may cause further deterioration in the already critical condition of patients with shock, sepsis, and acute inflammation. The effectiveness of infusion therapy of natural human IgG to such patients is suggested to depend partly upon the inhibition of the productivity of these cytokines. In this study, we investigated the modulation effects of IgG and its fragments on the production of TNF- and IL-1, on human peripheral blood mononuclear cells (PBMC). The production of TNF- and IL-1 was found to be dose-dependently inhibited by IgG when stimulated by lipopolysaccharide (LPS), phytohemagglutinin (PHA), concanavalin A (Con A), and interleukin-2 (IL-2). However, no inhibition was seen when stimulated by phorbormyristate acetate (PMA). The F(ab)₂ fragment showed enhancing effects on cytokine production by LPS, while the Fc fragment showed not as much inhibitory effect as whole intact IgG. IgG showed no direct cytotoxic effect on PBMC. These data suggest that natural human IgG inhibits TNF- and IL-1 production by PBMC through the Fc portion. The results of this study led us to conclude that whole intact IgG may be the best form of therapeutic delivery.     

Expression of pigment epithelium-derived factor and tumor necrosis factor-α is correlated in bladder tumor and is related to tumor angiogenesis

ObjectiveAngiogenesis is a pivotal process on which solid tumor growth is substantially dependent. Pigment epithelium-derived factor (PEDF) is the most potent natural anti-angiogenic factor, which has seldom been studied in bladder tumor, and whose functioning pathway remains unclear. We have thus investigated PEDF expression in relation to tumor necrosis factor-α (TNF-α) and microvessel density (MVD) with immunohistochemistry.MethodsAntibodies of PEDF and TNF-α were examined by Western blotting before immunohistochemistry. Sixty-four urothelial tumor sections and 23 normal controls were stained and expression of PEDF, TNF-α, and MVD were studied.ResultsDecreased PEDF expression and increased TNF-α expression was noticed in tumorous tissue compared with healthy urothelium. Lower PEDF expression was related to higher tumor grade but stage. Increased TNF-α expression was noticed in recurrent, larger tumors as well as in tumors with progression in grade and stage. Expression of PEDF and TNF-α was correlated in bladder tumor. PEDF or TNF-α was correlated with MVD negatively or positively, respectively, in cancerous tissue and tumorous grouping without correlation in papillary urothelial neoplasm of low malignant potential.ConclusionExpressional change of PEDF and TNF-α is in relation to angiogenesis of bladder tumor, especially in bladder cancer development.     

Potential role of tumor necrosis factor-α in downregulating sex hormone-binding globulin

Low plasma sex hormone-binding globulin (SHBG) levels are associated with obesity and predict the development of type 2 diabetes. The reason why obese individuals have low circulating SHBG has been attributed to hyperinsulinemia, but no mechanistic evidence has been described. The aim of the current study is to explore whether tumor necrosis factor-α (TNF-α) rather than insulin could be the main factor accounting for low SHBG levels in obesity. We performed in vitro and in vivo studies using human HepG2 cells and human SHBG transgenic mice. In addition, a cross-sectional study to explore the relationship between TNF-α and SHBG in obese patients and an interventional study to examine the effect of insulin administration on circulating SHBG in type 2 diabetic patients were performed. We provide evidence that TNF-α, but not insulin, is the main factor by which SHBG is reduced in obesity. Plasma SHBG was significantly increased rather than decreased after insulin treatment in diabetic patients. TNF-α-induced reduction of SHBG expression was mediated by downregulating HNF4A. Finally, a negative and independent correlation was found between plasma TNF-α receptor 1 and SHBG levels in obese patients. Our results suggest that TNF-α plays an important role downregulating SHBG in chronic low-grade inflammatory diseases such as obesity and type 2 diabetes.     

The role of tumor necrosis factor-α in Henoch-Schönlein purpura

Henoch-Schönlein purpura (HSP) is one of the most common types of vasculitis disorders in childhood and is characterized by a rash, arthritis, abdominal pain, and renal involvement. The factors that determine and mediate the severity of HSP and its renal involvement remain poorly understood, although it is likely that pro-inflammatory cytokines, including tumor necrosis factor- (TNF-), are involved in the pathogenesis. Serum and urine levels of TNF- were measured in children with HSP in the acute and convalescent phases by ELISA. Serum TNF- levels were significantly higher in proteinuric HSP in the acute phase (36.6±8.5 pg/ml) compared with those with HSP without renal involvement and those with hematuric HSP (25.4±4.5 and 27.1±3.9 pg/ml) (P<0.005). However, these significantly higher levels disappeared in the convalescent phase. Using matched serum samples from the same patients, serum TNF- levels of proteinuric HSP patients were significantly lower in the convalescent phase (29.9±4.6 pg/ml, P <0.05) than in the acute phase (39.1±8.2 pg/ml). Although urine TNF- levels were higher in proteinuric HSP in the acute phase and reduced in the convalescent phase, there were no significantly high or low levels. These results suggest that increased TNF- levels in the serum induce a series of functional and morphological changes in the glomerular cells in the acute phase and may be used as markers for monitoring the disease activity of HSP with severe renal involvement.     

Propofol reduces liver dysfunction caused by tumor necrosis factor-α production in Kupffer cells

Purpose

The present study, conducted in rats, investigated whether propofol attenuates lipopolysaccharide (LPS)-triggered liver dysfunction via regulation of tumor necrosis factor (TNF)-α production in activated Kupffer cells.

Methods

Rats received LPS (500 μg/kg) under Urethane? sedation (1 g/kg) in combination with propofol (5 mg/kg/h) or Intralipid? from 1 h before to 6 h after LPS administration. Some rats were treated with 10 mg/kg gadolinium chloride (GdCl₃) to induce Kupffer cell depletion. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), TNF-α mRNA and protein expression, caspase-3 activation and apoptosis were evaluated in hepatocytes. Immunofluorescence staining revealed expression of the pan-macrophage marker CD68 as well as TNF-α in Kupffer cells.

Results

ALT and AST serum levels increased approximately four-fold in LPS-exposed rats compared with Intralipid?-treated rats at 6 h after LPS administration, whereas propofol and GdCl₃ reduced the LPS-induced increases. LPS simultaneously augmented TNF-α expression in Kupffer cells, followed by increased caspase-3 activity and apoptosis in hepatocytes. Immunofluorescence staining and immunoblotting assay showed that TNF-α expression in Kupffer cells was inhibited by propofol and GdCl₃, resulting in a reduction of caspase-3 activity and apoptosis in LPS-treated rat hepatocytes.

Conclusions

Propofol (5 mg/kg/h) attenuated LPS-triggered liver dysfunction via inhibition of TNF-α production in activated Kupffer cells. These results suggest that propofol is capable of inhibiting inflammation-induced liver dysfunction in vivo.

     

The presence of tumor necrosis factor-α and its antibody in the sera of cachexic patients with gastrointestinal cancer

Although cancer cachexia has been shown to involve several cytokines, the tumor necrosis factor- (TNF) has rarely been detected in such patients. In this study, sera from 21 patients with cancer cachexia were examined for the presence of TNF and the anti-TNF antibody using an enzyme-linked immunosorbent assay (ELISA) and Western blotting, respectively. All of the patients had recurrent cancer and manifested the characteristics of progressive body weight loss. TNF was found in the sera of four patients (20%) at levels ranging from 10.4 to 53.1 pg/ml, while a positive reaction for the anti-TNF antibody was detected in the sera from six patients (30%), two of whom showed both TNF and its antibody. Thus, either TNF or the anti-TNF antibody was present in the sera from 8 of 21 patients (40%). The results of this study indicate that TNF may be present in the circulation of at least 40% of cachexic patients, and suggest that it may be one of the main mediators of cancer-associated cachexia.     

Increased human tumor necrosis factor-α levels induce procoagulant change in porcine endothelial cells in vitro

Lee KG, Lee H, Ha JM, Lee YK, Kang HJ, Park C‐G, Kim SJ. Increased human tumor necrosis factor‐α levels induce procoagulant change in porcine endothelial cells in vitro. Xenotransplantation 2012; 19: 186–195. © 2012 John Wiley & Sons A/S. Abstract: Background: Intravascular thrombosis and systemic coagulation abnormalities are major hurdles to successful xenotransplantation and are signs of acute humoral rejection. Increased expression of tissue factor (TF) is associated with the development of microvascular thrombosis in xenografts. To develop an effective strategy to prevent accelerated coagulation in xenografts, we investigated the mechanism by which porcine endothelial cells (PECs) become procoagulant after contact with human blood. Methods: The changes in TF mRNA levels and activity in PECs after incubation with 20% human serum or human bioactive molecules, including C5a, tumor necrosis factor‐α (TNFα) and interleukin (IL)‐1α, were evaluated using real‐time PCR and the factor Xa chromogenic assay, respectively. The procoagulant changes in PECs by these agonists were evaluated by measuring the coagulation time of human citrated plasma suspended with PECs pretreated with each agonist. TF expression and coagulation times were also assessed in PECs transfected with short interfering RNA (siRNA) designed to knock down porcine TF. We also examined the production of proinflammatory cytokines in human whole‐blood or plasma after contact with PECs, which were screened using the cytometric bead array system. TNFα levels were measured using ELISA in whole‐blood after contact with PECs, with or without the addition of xenoreactive antibodies or C1 esterase inhibitor. Results: Porcine TF mRNA and activity in PECs were up‐regulated in response to human TNFα and IL‐1α but were not affected by C5a or 20% human serum. Up‐regulation of TF expression by human TNFα or IL‐1α shortened PEC‐induced coagulation time, while siRNA‐mediated knockdown of TF expression prolonged coagulation time. The incubation of PECs with human whole‐blood led to a significant increase in human TNFα levels in the blood, which was promoted by the addition of xenoreactive antibodies and prevented by C1 esterase inhibitor. Conclusions: Human TNFα level increases in human blood after contact with PECs, which is attributed to xenoreactive antibody binding and subsequent complement activation. Human TNFα induces procoagulant changes in PECs with increased TF expression. This study suggests that human TNFα may be one of the mediators linking complement activation with procoagulant changes in the xenoendothelium.     

The association of promoter gene polymorphisms of the tumor necrosis factor-α and interleukin-10 with severity of lactic acidosis during liver transplantation surgery

Background

Orthotopic liver transplantation (OLT) is a major operation, causing cytokine release and other inflammatory responses that can contribute to postreperfusion syndrome occurrence. During the systemic inflammatory response syndrome, increased lactate levels result from excessive cytokine production despite normal oxygen delivery and carbohydrate metabolism. The goal of the study was to determine the relationship between genetic polymorphisms in interleukin (IL)-10 (−1082G/A) or tumor necrosis factor (TNF)-α (−376 G/A) and lactate levels in patients during OLT surgery.

Patients and Methods

This prospective observational study in 40 consecutive adult patients who underwent OLT documented lactic acid levels at 5 times: Immediately after induction of anesthesia, at the end of the pre-anhepatic phase, at the end of the anhepatic phase, 1 hour after reperfusion, and at the end of surgery. Polymerase chain reaction (PCR; RFLP methodology) was used to examine IL-10 (−1082G/A) and TNF-α (−376 G/A) gene polymorphisms.

Results

Carriers of the IL-10/TNF-α genotype combination GG/GG showed significantly different changes in lactate levels at 1 hour after reperfusion and at the end of surgery. Lactate levels were significantly higher among patients heterozygous for TNF-α (AG genotype) compared with patients homozygous for TNF-α (GG genotype) at same times. In contrast, there was no significant difference among IL-10 polymorphic genotypes (−1082G/A).

Conclusion

Genetic factors play a role in the development of lactic acidosis after OLT. IL-10 (−1082G/A) and TNF-α (−376 G/A) gene polymorphisms could influence the variability of lactate levels after liver transplantation surgery.     

Effects of interleukin-1, tumor necrosis factor-β, and forskolin on tissue plasminogen activator activity in human osteoblastic osteosarcoma cells

Summary The effects of interleukin-1 (IL-1), forskolin, and tumor necrosis factor (TNF-) on tissue plasminogen activator (t-PA) activity were studied in the human osteoblastic osteosarcoma cell line, G292. t-PA activity was measured in the cell media using the chromogenic substrate, S-2251. After a 24 hour incubation period, IL-1 increased t-PA in a dose-dependent manner. The effect of IL-1 at 10.0 U/ml was partially inhibited in the presence of indomethacin. Forskolin (1.0 M) increased t-PA activity after 24 hours with the effects of combined treatment of IL-1 (1.0 U/ml, 10.0 U/ml) and forskolin being apparently additive in nature. TNF- (10^-8–10^-7 M) also produced increased t-PA activity in the cell medial after a 24 hour incubation period. These results suggest that the cytokines, IL-1 and TNF-, can increase t-PA activity in G292 cells and that there is both a cAMP-dependent as well as a cAMP-independent pathway involved in the regulation of this osteoblastic cell function.     

Effect of tumor necrosis factor-α and interferon-γ on the growth of human prostate cancer cell lines

Human recombinant tumor necrosis factor- (rTNF-, 10^-12–10^-8 M) inhibited the proliferation of androgen-dependent LNCaP cells by 32–56%. In contrast, proliferation of androgen-independent PC-3 and JCA-1 cells was only slightly inhibited, or not inhibited at all, respectively. Human recombinant interferon- (rIFN-, 500 U/ml) decreased proliferation of PC-3 and JCA-1 cells by 35% and 53%, respectively, but had no effect on LNCaP cells. Interestingly, the combination of rIFN- and TNF- had greater antiproliferative effects on JCA-1 cells than treatment with either cytokine alone. However, the antiproliferative effects of this combination were similar to those observed for PC-3 or LNCaP cells treated with rIFN- or TNF- alone, respectively. These data suggest that some forms of androgen-independent prostate cancer may benefit from a combination therapy of IFN- and TNF-, while the use of IFN- alone may be more efficacious in others.     

Changes of interleukin-1 β, tumor necrosis factor α and interleukin-6 in brain and plasma after brain injury in rats

Objective: To study the changes of interleukin-1 β(IL-1β), tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) levels in brain and plasma after brain injury and to assess the relationship between the cytokine levels and injury severity in rats. Methods. A total of 51 male Wistar rats, weighing 280-340g, were anesthetized with chloral hydrate(400 mg/kg body weight) through intraperitoneal injection and fixed on a stereotaxic instrument. Severe brain injury was created in 16 rats (severe injury group) and moderate brain injury in 18 rats (moderate injury group) by a fluid percussion model, and cytokine levels of IL-1β, TNFα and IL-6 were measured with biological assay. And sham operation was made on the other 17 rats (control group). Results: In the control group, the levels of IL-1β,TNFα and IL-6 were hardly detected in the cortex of the rats, but in the ipsilateral cortex of the rats in both injury groups, they increased obviously at 8 hours after injury.The increasing degree of these cytokines had no significant difference between the two injury groups. The levels of IL-6 in the plasma of all the rats increased slightly, whereas the levels of IL-1β and TNFα were undetectable. Conc|usions: The increase of IL-1β, TNFα and IL-6 levels is closely related to brain injury. The increased cytokine levels in the central nervous system are not parallel to those in the peripheral blood. It suggests that inflammatory cytokines play important roles in the secondary neural damage after brain injury.     

Tumor necrosis factor-α plus actinomycin D-induced apoptosis of L929 cells is prevented by nitric oxide

S -nitroso-N-acetylpenicillamine protected cul-tured L929 cells from apoptosis induced by tumor necrosis factor-α (TNF-α) plus actinomycin D, as determined by the detection of DNA fragmentation and morphological changes. NO also prevented an enhancement of the production of reactive oxygen intermediates by TNF-α plus actinomycin D, as assessed by the oxidation of dihydrorhodamine 123 and hydroethidine. Because the inhibition of mitochondrial respiration by rotenone or antimycin A suppressed the increased oxidation of both dihydrorhodamine 123 and hydroethidine, it was suggested that TNF-α accelerated the leakage of reactive oxygen intermediates from the mitochondrial electron transport system. Polarography showed that NO reversibly inhibited mitochondrial respiration at either complexes I–III, II–III, or IV, thus suggesting the inhibition of cytochrome oxidase. Taken together, these findings indicate that the decreased mitochondrial formation of reactive oxygen intermediates in the presence of NO might have a protective effect against TNF-α plus actinomycin D-induced apoptosis. (Received for publication on July 16, 1998; accepted on May 28, 1999)     

Olmesartan inhibits the expression of monocyte chemoattractant protein-1 and tumor necrosis factor-α and improves vascular remodeling after vascular injury in mouse

Vscularinjuryinducesmigrationofsmoothmusclecells (SMCs)fromthemediatotheintimaandsubsequent proliferationofSMCswithintheintima .Thesevascularresponsesareproposedtobecriticalprocessesofneointimalformationandinducenarrowingofthevascularlumenandarteriosclerosis .1,3Manystudieshavedemonstratedthatangiotensinconvertingenzyme(ACE)inhibitors4 ,5inhibitneointimalformationintheinjuredmodelofsmallanimal,whereasotheragentsthathaveblood pressuredeclinedfailtopreventit.4 Ininjuredarteries,theexpression…