Screening of TNFR1 Binding Peptides from Deinagkistrodon acutus Venom through Phage Display

The venomous species Deinagkistrodon acutus has been used as anti-inflammatory medicine in China for a long time. It has been proven to have anti-inflammatory activity, but its specific anti-inflammatory components have not yet been fully elucidated. Tumor necrosis factor receptor-1 (TNFR1), which participates in important intracellular signaling pathways, mediates apoptosis, and functions as a regulator of inflammation, is often used as the target to develop anti-inflammatory drugs. The small peptides of snake venom have the advantages of weak immunogenicity and strong activity. To obtain the specific TNFR1 binding peptides, we constructed a T7 phage library of D. acutus venom glands, and then performed biopanning against TNFR1 on the constructed library. After biopanning three times, several sequences with potential binding capacity were obtained and one 41-amino acid peptide was selected through a series of biological analyses including sequence length, solubility, and simulated affinity, named DAvp-1. After synthesis, the binding capacity of DAvp-1 and TNFR1 was verified using surface plasmon resonance technology (SPR). Conclusively, by applying phage display technology, this work depicts the successful screening of a promising peptide DAvp-1 from D. acutus venom that binds to TNFR1. Additionally, our study emphasizes the usefulness of phage display technology for studies on screening natural product components.

Effects of TNFα receptor TNF-Rp55- or TNF-Rp75- deficiency on corneal neovascularization and lymphangiogenesis in the mouse

Tumor necrosis factor (TNF)α is an inflammatory cytokine likely to be involved in the process of corneal inflammation and neovascularization. In the present study we evaluate the role of the two receptors, TNF-receptor (TNF-R)p55 and TNF-Rp75, in the mouse model of suture-induced corneal neovascularization and lymphangiogenesis. Corneal neovascularization and lymphangiogenesis were induced by three 11-0 intrastromal corneal sutures in wild-type (WT) C57BL/6J mice and TNF-Rp55-deficient (TNF-Rp55d) and TNF-Rp75-deficient (TNF-Rp75d) mice. The mRNA expression of VEGF-A, VEGF-C, Lyve-1 and TNFα and its receptors was quantified by qPCR. The area covered with blood- or lymphatic vessels, respectively, was analyzed by immunohistochemistry of corneal flatmounts. Expression and localization of TNFα and its receptors was assessed by immunohistochemistry of sagittal sections and Western Blot. Both receptors are expressed in the murine cornea and are not differentially regulated by the genetic alteration. Both TNF-Rp55d and TNF-Rp75d mice showed a decrease in vascularized area compared to wild-type mice 14 days after suture treatment. After 21 days there were no differences detectable between the groups. The number of VEGF-A-expressing macrophages did not differ when comparing WT to TNF-Rp55d and TNF-Rp75d. The mRNA expression of lymphangiogenic markers VEGF-C or LYVE-1 does not increase after suture in all 3 groups and lymphangiogenesis showed a delayed effect only for TNF-Rp75d. TNFα mRNA and protein expression increased after suture treatment but showed no difference between the three groups. In the suture-induced mouse model, TNFα and its ligands TNF-Rp55 and TNF-Rp75 do not play a significant role in the pathogenesis of neovascularisation and lymphangiogenesis.

Role of TNF-α and Its Receptors in Pericoronitis

The classic stimulus for cellular cytokine production is bacterial lipopolysaccharide (endotoxin). It was therefore hypothesized that tumor necrosis factor-α (TNF-α) may be responsible for pericoronitis. TNF-α and its receptors were detected by immunohistochemical staining in third molar pericoronitis in ten patients and ten healthy control samples. The percentage of TNF-α positive cells was high in pericoronitis (p = 0.0317). TNF receptors TNF-R1 and TNF-R2 were found in macrophage- and fibroblast-like cells, vascular endothelial cells in post-capillary venules, and basal epithelial cells in pericoronitis, but were only weakly expressed in controls. Increased expression of interleukin-1β and vascular cell adhesion molecule-1 was found as a biological indicator of TNF-α ligand-receptor interaction. Explanted tissues acquired destructive potential upon TNF-α stimulation, whereas TNF-α blockers controlled it in inflamed tissues. These findings suggest that, in pericoronitis, inflammatory and resident cells produce and respond to potent pro-inflammatory cytokine TNF-α, with pathogenic and potential therapeutic relevance.

Selective permeabilization of the blood-brain barrier at sites of metastasis

BACKGROUND

Effective chemotherapeutics for primary systemic tumors have limited access to brain metastases because of the blood-brain barrier (BBB). The aim of this study was to develop a strategy for specifically permeabilizing the BBB at sites of cerebral metastases.

METHODS

BALB/c mice were injected intracardially to induce brain metastases. After metastasis induction, either tumor necrosis factor (TNF) or lymphotoxin (LT) was administered intravenously, and 2 to 24 hours later gadolinium- diethylenetriaminepentaacetic acid, horseradish peroxidase, or radiolabeled trastuzumab ((111)In-BnDTPA-Tz) was injected intravenously. BBB permeability was assessed in vivo using gadolinium-enhanced T1-weighted magnetic resonance imaging and confirmed histochemically. Brain uptake of (111)In-BnDTPA-Tz was determined using in vivo single photon emission computed tomography/computed tomography. Endothelial expression of TNF receptors was determined immunohistochemically in both mouse and human brain tissue containing metastases. Group differences were analyzed with one-way analysis of variance followed by post hoc tests, Wilcoxon signed rank test, and Kruskal-Wallis with Dunn's multiple comparison test. All statistical tests were two-sided.

RESULTS

Localized expression of TNF receptor 1 (TNFR1) was evident on the vascular endothelium associated with brain metastases. Administration of TNF or LT permeabilized the BBB to exogenous tracers selectively at sites of brain metastasis, with peak effect at 6 hours. Metastasis-specific uptake ratio of (111)In-BnDTPA-Tz was also demonstrated after systemic TNF administration vs control (0.147±0.066 vs 0.001±0.001). Human brain metastases displayed a similar TNF receptor profile compared with the mouse model, with predominantly vascular TNFR1 expression.

CONCLUSIONS

These findings describe a new approach to selectively permeabilize the BBB at sites of brain metastases to aid in detection of micrometastases and facilitate tumor-specific access of chemotherapeutic agents. We hypothesize that this permeabilization works primarily though TNFR1 activation and has the potential for clinical translation.

Predictive value of conjointly examined IL-1ra, TNF-R I, TNF-R II, and RANTES in patients with primary glomerulonephritis

Interleukin-1 receptor antagonist (IL-1ra), tumor necrosis factor soluble receptors (sTNF-R) type I and II, and regulated upon activation, normal T-cell expressed and secreted (RANTES) play an important role in the modulation of primary glomerulonephritis (GN) course. The aim of the study was to assess whether pre-treatment measurements of IL-1ra, sTNF-R, and RANTES assessed conjointly may be useful as predicting factors in patients with GN. In 84 patients (45 males and 39 female) serum concentration (pg/mL) and urinary excretion (pg/mgCr) of cytokines were measured. After 12 months of therapy with steroids and cyclophosphamide the patients were divided into two subgroups: Responders (R) and Non-Responders (NR) according to the treatment results. The urinary IL-1ra, TNF-RI and RII were significantly higher in R than NR (1,732 vs 646 with P < 0.001, 13.1 vs 6.3 with P = 0.005, and 33.6 vs 14.4 with P = 0.012). The urinary RANTES excretion was increased in NR (79.6 vs 28.5; P < 0.001). The multivariable analysis showed that if conjointly assessed, only urinary IL-1ra, TNF-R I and R II, RANTES with 85% probability pointed the feature remission (R). In conclusion, the urinary excretion of IL-1ra, TNF-R I and R II, and RANTES examined conjointly are effective in predicting favorable response to immunosuppressive treatment in patients with GN.

The presence of TNF-alpha and TNFR1 in aseptic root resorption. A preliminary study

BACKGROUND

It is hypothesised that osteoprotegerin (OPG), as an osteoclast antagonist, may offer molecular control over the process of orthodontic root resorption. Previous work investigating OPG in a rat periodontal ligament (PDL) ankylosis model found no inhibitory effect on osteoclasts and odontoclasts when given at a recommended dosage of 2.5 mg/kg. It was considered that traumatically-induced PDL inflammation produces mediators and cytokines with the ability to stimulate clast cell differentiation and counter the effects of OPG.

AIMS

The present study investigated the presence of Tumour Necrosis Factor Alpha (TNF-alpha) and its receptor Tumour Necrosis Factor Receptor 1 (TNFR1) in a PDL sterile inflammatory model.

METHODS

Dry ice was applied for 15 minutes to the upper right first molar crown of eighteen, 8-week-old, male Sprague-Dawley rats of which 9 were injected with OPG at a dose of 2.5 mg/kg of body weight at the time of freezing. After 7 days, the rats were sacrificed and each maxilla processed for immunohistochemical identification of TNF-alpha and TNFR1.

RESULTS

Results showed the presence of root resorption in varying amounts and locations in both experimental and control rats. Reparative processes appeared greater in the OPG-treated rats, often with the presence of an ankylotic union. Immunolabelling showed the presence of TNF-alpha and TNFR1 in the sterile inflammation located mainly in the interradicular PDL area. More definitive labelling appeared in OPG-treated rats.

CONCLUSION

The results indicated that TNF-alpha, and its receptor TNFR1, by their presence, may modify OPG effectiveness by offering an alternative pathway for osteoclast formation, which counters the anti-resorptive effects of OPG.

Inhibition of lung cancer cell proliferation by CD40 signaling through tumor necrosis factor I

BACKGROUND AND OBJECTIVE

CD40 signaling induces growth inhibition in some tumor cells in vitro, but the precise molecular mechanism remains unclear. This study was to investigate the biological effects and mechanisms of CD40 stimulation on proliferation of lung cancer cell lines NCI-H460 and A549, changes in tumor necrosis factor receptors (TNFRs) and membrane tumor necrosis factor alpha (mTNF-alpha).

METHODS

The expression of CD40 on the cell surface, and changes in TNFR and mTNF-alpha expression after CD40 stimulation were detected by the immunofluorescence technique and flow cytometry. Changes in protein contents of TNFR as well as mTNF-alpha expression after CD40 stimulation were measured by western blot. The cell proliferation rate was determined by MTT assay. The content of soluble TNF-alpha(sTNF-alpha) in the supernatant of lung cancer cells was measured by ELISA assay.

RESULTS

The expression rates of CD40 in NCI-H460 and A549 were (89.0 +/- 3.2)% and (62.2 +/- 4.5)%, respectively. After 48 h of CD40 stimulation, the expression rates of TNFRI in NCI-H460 and A549 became significantly higher [(36.2 +/- 4.6)% and (38.5 +/- 5.9)%] than those in the corresponding control cells [(15.2 +/- 3.1)% and (7.2 +/- 1.9)%] (p < 0.05); while the expression rates of TNFRII were significantly lower than those in the control cells [(18.0 +/- 1.6)% and (5.8 +/- 1.2)% vs. (58.1 +/- 3.6)% and (38.8 +/- 4.3)%] (p < 0.05); the expression rates of mTNF-alpha were decreased in the two cell lines [(8.7 +/- 1.1)% and (7.0 +/- 0.9)%] as compared to those in control cells [(15.0 +/- 2.1)% and (26.5 +/- 3.2)%] (p < 0.05). The level of TNFRI protein was elevated with the downregulation of TNFRII protein in NCI-H460 and A549. The level of mTNF-alpha protein remained unchanged in the two cell lines. TNF-alpha was not detectable in the supernatant of lung cancer cells. Moreover, cell proliferation of NCI-H460 and A549 were inhibited after CD40 stimulation (p < 0.05), but the inhibition effect disappeared after blocking TNFRI. Blocking of TNF-alpha inhibited cell proliferation of the two cell lines (p < 0.05), but a synergistic effect was not observed after simultaneous stimulation with CD40.

CONCLUSION

CD40 signaling inhibits the proliferation of CD40-positive lung cancer cells through mTNF-alpha/TNFRI in vitro.

Increased serum levels of inflammatory markers in chronic institutionalized patients with schizophrenia

Activation of the cytokine systems may be involved in the neuropathological changes occurring in the central nervous systems of schizophrenic patients. However, associations between the levels of cytokines and the severity of symptoms have not been completely established.

OBJECTIVE

It was the aim of this study to evaluate serum levels of tumor necrosis factor (TNF)-alpha and their soluble receptors (sTNFR) in schizophrenic patients and healthy controls.

METHODS

Forty male institutionalized schizophrenic patients (mean age +/- SD, 52.3 +/- 9.9 years) and 20 asymptomatic matched controls were recruited. The severity of symptoms was assessed using the Brief Psychiatric Rating Scale, the Positive and Negative Syndrome Scale and the Abnormal Involuntary Movement Scale. Serum levels of cytokines were measured by ELISAs.

RESULTS

Serum levels of sTNFR1 and sTNFR2 were increased in schizophrenic patients when compared with controls (all p < 0.05), but there was no difference in TNF-alpha levels. There was no correlation between the length of disease/hospitalization or the severity of symptoms and the serum levels of these molecules.

CONCLUSION

Inflammatory markers are increased in schizophrenia but they do not correlate with symptom severity.

The effect of treatment of cystic fibrosis pulmonary exacerbations on airways and systemic inflammation

BACKGROUND

Chronic infection in cystic fibrosis (CF) and airway inflammation leads to progressive lung injury. Neutrophils are considered to be responsible for the onset and promotion of the inflammatory response within the CF lung. The relationship between infection and inflammation is complex but circulating inflammatory markers may not truly reflect the local inflammatory response in the lung. The aims of this study were to investigate the change of inflammatory biomarkers and cells within sputum and blood before and after intravenous antibiotics for a pulmonary exacerbation of CF.

METHODS

Assays included neutrophil elastase (NE) and complex, interleukin-8 (IL-8) and soluble intercellular adhesion molecule-1 (sICAM-1), fas ligand (FAS-L), and TNFr-1. Analysis of sputum cell differential and absolute cell counts and immunocytochemistry (CD11b and CD95) on sputum and isolated blood neutrophils were carried out.

RESULTS

There were no significant differences in absolute or differential sputum cell counts or sputum sol measurements following antibiotics. There was a significant increase in the percentage of blood neutrophils with minimal CD11b staining, 28 (4.1) mean percentage (SEM) versus 41 (2.9) and a decrease in the percentage showing maximal staining 30 (0.5) versus 15 (2.5). There was a significant increase in the percentage of blood neutrophils without CD95 staining, 43 (5.4) mean percentage versus 52 (5.1).

CONCLUSION

These data suggest a modifiable systemic response to i.v. antibiotics but a local sustained inflammatory response in the lung.

TNF-alpha and shear stress-induced large artery adaptations

BACKGROUND

Tumor necrosis factor-alpha (TNF-alpha) up-regulation has been associated with both low and high shear-induced arterial remodeling. To address this apparent paradox and to define the biology of TNF-alpha signaling in large arteries, we tested the hypotheses that differential temporal expression of TNF-alpha drives shear-regulated arterial remodeling.

MATERIALS AND METHODS

Both low- and high-shear environments in the same rabbit were surgically created for common carotid arteries. Common carotid arteries (n = 60 total) were harvested after d0, d1, d3, d7, and d14 and analyses included morphology, TNF-alpha, and IL-10 mRNA quantitation. In separate experiments, animals received pegylated soluble TNF-alpha Type 1 receptor (PEG sTNF-RI) or vehicle via either short- or long-term dosing to define the effect of TNF-alpha blockade.

RESULTS

The model yielded a 14-fold shear differential (P < 0.001) with medial thickening under low shear (P = 0.025), and evidence of outward remodeling with high shear (P = 0.007). Low shear immediately up-regulated TNF-alpha expression approximately 50 fold (P < 0.001) at d1. Conversely, high shear-induced delayed and sustained TNF-alpha expression (22-fold at d7, P = 0.012; 23-fold at d14, P = 0.007). Both low and high shear gradually induced IL-10 expression (P = 0.002 and P = 0.004, respectively). Neither short-term (5-day) nor long-term (14-day) blockage of TNF-alpha signaling resulted in treatment-induced changes in the remodeling of low- or high-shear arteries.

CONCLUSIONS

Shear stress differentially and temporally regulates TNF-alpha expression in remodeling large arteries. However, TNF-alpha blockage did not substantially impact the final shear-induced morphology, suggesting that large arteries can remodel in response to flow perturbations independent of TNF-alpha signaling.

Tumor necrosis factor receptors (TNFRs) on T lymphocytes and soluble TNFRs in different clinical courses of sarcoidosis

INTRODUCTION

The release of tumor necrosis factor (TNF-alpha) is increased in sarcoidosis patients. TNF-alpha exerts its effect by binding to specific cell surface receptors. There are only fragmentary data concerning the expression of tumor necrosis factor receptors (TNFRs) on bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) lymphocytes. The aim of the study was to evaluate TNFRI (CD120a) and TNFRII (CD120b) expression on T cells and the level of soluble TNFRs in specimens of patients with different clinical manifestation and clinical outcome of sarcoidosis.

MATERIAL AND METHODS

We examined 49 patients with newly diagnosed pulmonary sarcoidosis. TNFRI and TNFRII density on CD4+ and CD8+ BALF and PB cells surface was estimated using monoclonal antibodies and a flow cytometry technique. The level of TNFRs in PB serum and BALF cell culture supernatant (CCS) was measured using ELISA. Immunological analyses were also performed on PB samples collected from 10 healthy volunteers.

RESULTS

The level of soluble TNFRI (sTNFRI) in PB serum was similar in sarcoidosis patients and healthy subjects, whereas the concentration of sTNFRII in serum was significantly higher in the sarcoidosis group (P<0.001). Patients without acute symptoms of sarcoidosis, patients with radiological stage II/III as well as patients with further disease progression showed a tendency to higher levels of sTNFRs in PB serum and lower levels of sTNFRs in BALF CCS compared to Löfgren syndrome and radiological stage I subjects, and patients with spontaneous resolution of sarcoidosis. More than 80% of BALF and PB lymphocytes of sarcoidosis patients expressed both CD120a and CD120b antigens. The percentage of double-positive CD4+CD120a+ and CD4+CD120b+ cells in PB was significantly higher (P<0.005) in sarcoidosis patients than in healthy subjects. The highest percentage of CD4+CD120a+ and CD4+CD120b+ lymphocytes in BALF was determined in patients with acute disease, and in PB of patients with further spontaneous improvement.

CONCLUSION

The evaluation of sTNFRs and TNFRs expression on T-helper cells may be useful in the estimation of sarcoidosis activity.

TIMP-3 Ameliorates Hepatic Ischemia/Reperfusion Injury Through Inhibition of Tumor Necrosis Factor-Alpha-Converting Enzyme Activity in Rats

BACKGROUND

Tumor necrosis factor (TNF)-alpha and its receptors play a critical role in the inflammatory cascade after hepatic ischemia/reperfusion injury. TNF-alpha converting enzyme (TACE) or disintegrin and metalloproteinase (ADAM)-17 is a metalloproteinase disintegrin that specifically cleaves precursor TNF-alpha to its mature form and is involved in the ectodomain shedding of TNF receptors. The regulation of TACE is poorly understood and its role in liver injury and/or regeneration is unknown.

METHODS

Male Wistar rats were subjected to 10 or 30 min of partial warm hepatic ischemia followed by 3 to 24 hr of reperfusion. Serum and/or hepatic TACE, TNF-alpha, TNF receptor 1 (TNFR1), and interleukin (IL)-6 levels were assessed by enzyme-linked immunosorbent assay, real-time reverse-transcriptase polymerase chain reaction, and/or Western blot.

RESULTS

Low levels of TACE were detected in normal liver tissue. Both 10 and 30 min warm ischemia resulted in a rise in TACE expression which peaked six hr after reperfusion. TNF-alpha, TNFR1, and IL-6 levels were up-regulated in a pattern similar to TACE messenger RNA (mRNA) levels. Moreover, selective inhibition of TACE activity by specific inhibitor tissue inhibitor of metalloproteinase (TIMP)-3 at dosages of 100 or 1000 ng/kg body weight showed significant decrease of circulating TNF-alpha and serum alanine transferase (ALT) levels and histological improvement of hepatic ischemia/reperfusion injuries.

CONCLUSIONS

TACE expression and its activity, as measured by increases in TNF-alpha, TNFR1, and IL-6 levels, are increased following hepatic ischemia/reperfusion injury, implying that TACE plays an important role in hepatic ischemia/reperfusion injury. Amelioration of hepatic ischemia/reperfusion injury after inhibition of TACE activity by TIMP-3 suggests that TACE inhibition may play an important role in preventing liver ischemia/reperfusion injury warranting further experimental and clinical study.

Inhibition of receptor internalization attenuates the TNFalpha-induced ROS generation in non-phagocytic cells

Reactive oxygen species (ROS) are important regulatory molecules implicated in the signaling cascade triggered by tumor necrosis factor (TNF)alpha, although the events through which TNFalpha induces ROS generation are not well characterized. Here, we report that TNFalpha-induced ROS production was blocked by pretreatment with internalization inhibitor monodansyl cadaverine (MDC). Similarly, a transient expression of a GTP-binding and hydrolysis-defective dynamin mutant (dynamin(K44A)) that had been shown to be defective in internalization significantly attenuated the TNFalpha-induced intracellular ROS production. Importantly, the inhibition of receptor internalization suppressed TNFalpha signaling to mitogen-activated protein kinases (MAPKs) stimulation. Together, our results suggest that receptor internalization is somehow necessary for the TNFalpha-induced ROS generation and subsequent intracellular downstream signaling in non-phagocytes.

Activation of mouse natural killer T cells accelerates liver regeneration after partial hepatectomy

BACKGROUND & AIMS

Activation of natural killer T cells with the synthetic ligand alpha-galactosylceramide (alpha-GalCer) induced hepatotoxicity through the tumor necrosis factor (TNF) and Fas-ligand-mediated pathway in aged mice. The aim of this study was to elucidate how alpha-GalCer-activated natural killer T cells function in hepatocyte proliferation and liver regeneration in partially hepatectomized (PHx) mice.

METHODS

Mice were injected with alpha-GalCer at 36 hours after 70% PHx. Hepatocyte mitosis was evaluated by either mitotic figures or proliferating cell nuclear antigen staining. The role of TNF and Fas-ligand in hepatocyte mitosis also was assessed.

RESULTS

In PHx mice injected with alpha-GalCer, hepatocyte mitosis was greatly enhanced at 44 hours after surgery and the increase was more obvious in aged mice than in young mice. The expression of both TNF receptor 1 and Fas-ligand in liver natural killer T cells tended to increase after alpha-GalCer injection in PHx mice. Treatment of mice with anti-NK1.1 Ab 3 days before and just after hepatectomy greatly inhibited the effect of alpha-GalCer on hepatocyte mitosis and liver regeneration. Furthermore, pretreatment of PHx mice with either anti-TNF Ab or anti-FasL Ab 1 hour before alpha-GalCer injection mostly abrogated the increase in hepatocyte proliferation. alpha-GalCer injection did not accelerate hepatocyte proliferation in Fas-mutated lpr mice after PHx. CD1d-/- mice without alpha-GalCer injection showed decreased hepatocyte mitosis after PHx.

CONCLUSIONS

Activated natural killer T cells help hepatocyte proliferation and liver regeneration after PHx via the TNF and Fas/Fas-ligand-mediated pathway.

Role of tumor necrosis factor-alpha and its receptors in human benign breast lesions and tumors (in situ and infiltrative)

The aim of the present study was to characterize the expression pattern of tumor necrosis factor (TNF)-alpha and its receptors in breast samples (benign diseases, in situ carcinomas and infiltrating carcinomas), and to compare these results with those obtained previously for interleukin-6, p53 and p21 using the same samples in order to elucidate the effects of these cytokines on the proliferation-apoptosis equilibrium. Immunoexpression of TNF-alpha and its receptors (TNFRI and TNFRII) were studied by western blotting and immunohistochemistry. The percentage of samples positive for TNF-alpha and TNFRII was higher in in situ carcinoma than in benign breast diseases, and TNFRII was even higher in infiltrating tumors. The percentage of samples positive for TNFRI was similar in the three groups. For the three proteins and in the three patient groups, immunoreactions were observed in the peripheral cytoplasm. In the positive samples, immunostaining for TNF-alpha was more intense in infiltrating tumors than in the other two patient groups, whereas immunostaining for both receptors was higher in in situ carcinoma than in benign breast diseases, and even higher in infiltrating tumors. Comparing the TNF-alpha results with previous results for mtp53, p21 and interleukin-6, we found an association between the expression of these four proteins and increasing malignancy. TNF-alpha might be an important factor in breast cancer promotion as its proliferation and survival effects seems to be enhanced through the increased expression of TNFRII. Also, the pro-apoptotic pathway of TNFRI could be inhibited by p21 (which appeared increased in breast cancer), altering TNFRI effects in promoting the expression of several factors, such interleukin-6, which contribute to tumor promotion.

DELAYED ELEVATION OF SOLUBLE TUMOR NECROSIS FACTOR RECEPTORS P75 AND P55 IN CEREBROSPINAL FLUID AND PLASMA AFTER TRAUMATIC BRAIN INJURY

Recent studies have reported a significant inflammatory reaction in the brain and the systemic circulation after traumatic brain injury (TBI). Although there is growing knowledge and understanding of the mechanisms and mediators involved in the proinflammatory reaction, little is known about the anti-inflammatory mediators in the brain. As tumor necrosis factor alpha (TNF-alpha) plays a detrimental role in the initiation and promotion of the proinflammatory reactions after TBI, the endogenous scavenger system, represented by the soluble TNF receptors (sTNFRs) p55 and p75, seems to have an important anti-inflammatory capacity by binding to circulating TNF-alpha. To evaluate this potentially anti-inflammatory response to trauma, we analyzed sTNFR p55 and p75 in paired plasma/cerebrospinal fluid (CSF) samples of 29 patients who encountered TBI. Values were compared with reference values obtained from healthy volunteers (n = 91). Patients with TBI showed significantly (P < 0.001) elevated sTNFR p55 and p75 values starting from day 2 and lasting until day 10 if compared with reference values. In contrast to the early increased plasma values p55 and p75 showed slowly increasing CSF values starting on day 4 and 3, respectively. Significantly (P < 0.001) increased CSF values of p 55 were determined on days 4 to 6 and day 9. p75 showed significantly (P < 0.001) elevated values if compared with control values on days 7 and 9. The sTNFR p55 and p75 show a distinct and long-lasting elevation in plasma of patients after TBI. In contrast, CSF values display a delayed and less intense elevation of both receptors in patients with TBI. These findings are suggestive of an imbalance of the proinflammatory and anti-inflammatory reactions of the central nervous system after trauma, with an emphasis on the proinflammatory mechanisms and a slow increase of potentially anti-inflammatory mediators such as the soluble TNFRs after TBI.

Effect of liver regeneration after partial hepatectomy and ischemia-reperfusion on expression of growth factor receptors

AIM: To investigate the effects of experimental partial hepatectomy and normothermic ischemia-reperfusion damage on the time course of the expression of four different growth factor receptors in liver regeneration. This is relevant due to the potential therapeutic use of growth factors in stimulating liver regeneration.

METHODS: For partial hepatectomy (PH) 80% of the liver mass was resected in Sprague Dawley rats. Ischemia and reperfusion (I/R) were induced by occlusion of the portal vein and the hepatic artery for 15 min. The epidermal growth factor receptor, hepatic growth factor receptor, fibroblast growth factor receptor and tumour necrosis factor receptor-1 were analysed by immunohistochemistry up to 72 h after injury. Quantitative RT-PCR was performed at the time point of minimal receptor expression (24 h).

RESULTS: In immunohistochemistry, EGFR, HGFR, FGFR and TNFR1 showed biphasic kinetics after partial hepatectomy with a peak up to 12 h, a nadir after 24 h and another weak increase up to 72 h. During liver regeneration, after ischemia and reperfusion, the receptor expression was lower; the nadir at 24 h after reperfusion was the same. To evaluate whether this nadir was caused by a lack of mRNA transcription, or due to a posttranslational regulation, RT-PCR was performed at 24 h and compared to resting liver. In every probe there was specific mRNA for the receptors. EGFR, FGFR and TNFR1 mRNA expression was equal or lower than in resting liver, HGFR expression after I/R was stronger than in the control.

CONCLUSION: At least partially due to a post-transcrip-tional process, there is a nadir in the expression of the analysed receptors 24 h after liver injury. Therefore, a therapeutic use of growth factors to stimulate liver regeneration 24 h after the damage might be not successful.

Elevated interferon gamma expression in the central nervous system of tumour necrosis factor receptor 1-deficient mice with experimental autoimmune encephalomyelitis

Inflammation in the central nervous system (CNS) can be studied in experimental autoimmune encephalomyelitis (EAE). The proinflammatory cytokines interferon-gamma (IFN-gamma) and tumour necrosis factor (TNF) are implicated in EAE pathogenesis. Signals through the type 1 TNF receptor (TNFR1) are required for severe EAE to develop, whereas deficiency in IFN-gamma or its receptor result in more severe EAE. We investigated IFN-gamma expression in TNFR1-deficient (TNFR1-/-) mice. We describe here that there were more IFN-gamma-secreting T cells present in the CNS of TNFR1-/- mice during EAE compared to wild-type (WT) mice, despite that clinical symptoms were mild, with delayed onset. There was greater expression of IL-12/23p40 by antigen-presenting cells in these mice, and in vitro, TNFR1-/- antigen-presenting cells induced greater secretion of IFN-gamma but not interleukin (IL)-17 when cultured with primed T cells than did WT antigen presenting cells. TNFR1-/- mice with EAE had significantly higher expression of CXCL10 mRNA (but not CCL5 mRNA) in the CNS compared to WT mice with EAE. These data demonstrate that IFN-gamma expression is enhanced in the CNS of TNFR1-/- mice with EAE and suggest that IFN-gamma levels do not necessarily correlate with EAE severity.

Gene expression profiling of primary cultures of ovarian epithelial cells identifies novel molecular classifiers of ovarian cancer

In order to elucidate the biological variance between normal ovarian surface epithelial (NOSE) and epithelial ovarian cancer (EOC) cells, and to build a molecular classifier to discover new markers distinguishing these cells, we analysed gene expression patterns of 65 primary cultures of these tissues by oligonucleotide microarray. Unsupervised clustering highlights three subgroups of tumours: low malignant potential tumours, invasive solid tumours and tumour cells derived from ascites. We selected 18 genes with expression profiles that enable the distinction of NOSE from these three groups of EOC with 92% accuracy. Validation using an independent published data set derived from tissues or primary cultures confirmed a high accuracy (87–96%). The distinctive expression pattern of a subset of genes was validated by quantitative reverse transcription–PCR. An ovarian-specific tissue array representing tissues from NOSE and EOC samples of various subtypes and grades was used to further assess the protein expression patterns of two differentially expressed genes (Msln and BMP-2) by immunohistochemistry. This study highlights the relevance of using primary cultures of epithelial ovarian cells as a model system for gene profiling studies and demonstrates that the statistical analysis of gene expression profiling is a useful approach for selecting novel molecular tumour markers.

Two pathways of apoptosis are simultaneously induced in the embryonal brains of neural cell-specific HIF-1α-deficient mice

The aim of this study was to clarify the mechanism of apoptosis seen in the cortex of neural cell-specific hypoxia inducible factor-1alpha (HIF-1alpha)-deficient embryos. A previous study showed that the neural cells in the cortical area of the mutant embryos underwent apoptosis coincident with vascular regression. Through histological, immunohistochemical, and electron microscopic technique, two kinds of apoptotic cells were detected in the mutant embryonal cortex. Apoptotic cells of one type were clustered in small round structures, 10-20 mum in diameter, whereas the others, present in large numbers, were distributed in a group at the cortical plate located more to the outer side than the round structures. The histochemical and electron microscopic findings indicate that the former represented the appearance of macrophages, in which cellular fragments including vascular cells underwent oxidative stress-related, TNF receptor-mediated, caspase-2-induced apoptosis, while the latter showed c-Myc-related, caspase-3-activated apoptosis of the neural cells. These results suggest that two pathways of apoptosis are induced in neuronal and vascular cells of the cortex in the neural cell-specific HIF-1alpha-deficient mouse.

Autoinduction of tumor necrosis factor-alpha in FRTL-5 rat thyroid cells

Tumor necrosis factor-alpha (TNFalpha) may play a role in the development of autoimmune thyroiditis such as Hashimoto's thyroiditis. In the present study, we examined whether TNFalpha induced its own expression in FRTL-5 rat thyroid cells. Lipopolysaccharide (LPS) markedly increased TNFalpha mRNA levels in FRTL-5 cells as assessed by semiquantitative RT-PCR. In addition, LPS-stimulated cells released TNFalpha protein into the culture medium. Similarly, TNFalpha induced its own gene and protein expression in FRTL-5 cells as assessed by RT-PCR and metabolic labeling and immunoprecipitation of TNFalpha. The autoinduction of TNFalpha gene was also observed in TNFalpha-stimulated human thyroid epithelial cells. TNFalpha induction was specific to LPS and TNFalpha since interferon-alpha or amiodarone failed to increase TNFalpha mRNA levels in FRTL-5 cells. Human TNFalpha induced rat TNFalpha gene expression, indicating that type 1 TNF receptor (TNF-R) is involved in the autoinduction. TNFalpha did not increase either type 1 or type 2 TNF-R mRNA levels, suggesting that upregulation of TNF receptors is not involved in the autoinduction of TNFalpha. Although the biological significance of autoinduction of TNFalpha remains unclear, our results suggest that thyroid epithelial cells may participate in the development of autoimmune thyroiditis through production of TNFalpha. Furthermore, inhibition of TNFalpha production in the thyroid may represent a novel approach to mitigating inflammation in autoimmune thyroiditis.

Cytokine imbalance in infants receiving extracorporeal membrane oxygenation for respiratory failure

BACKGROUND

It is likely that the imbalance between the pro- and anti-inflammatory cytokines will determine the outcome in infants with severe respiratory failure receiving extracorporeal membrane oxygenation (ECMO).

AIMS

We determined if there was an imbalance between pro- and anti-inflammatory cytokines in serial bronchoalveolar lavage (BAL) fluid obtained from survivors and non-survivors of ECMO.

METHODS

We therefore measured the cellular changes and the molar ratios of pro-inflammatory and anti-inflammatory cytokines in serial BAL fluid obtained from survivors and non-survivors of ECMO. Fifteen infants surviving ECMO (median age 1 day, range 1-120) and 7 who did not (28 days, range 1-402) were studied.

RESULTS

In the lungs of survivors, the increased proportion of airway neutrophils at presentation decreased with time and was matched by a parallel increase in percent alveolar macrophages as the infants' condition improved. The pro- and anti-inflammatory pulmonary cytokine ratios were static in the survivors. In the non-survivors, the ratio of tumour necrosis factor-alpha (TNF-alpha) against soluble TNF-receptor 1 (sTNF-R1) and soluble TNF receptor 2 (sTNF-R2) was increased at days 2-3 when compared to the survivors, but the molar ratio interleukin-1beta (IL-1beta)/soluble IL-1 receptor antagonist (sIL-1RA) was largely undetectable due to undetectable IL-1beta.

CONCLUSIONS

These data suggest that the infants who survive ECMO resolve their pulmonary inflammation and that in non-survivors the ratio of TNF-alpha against its receptor antagonists is increased and is associated with a poor outcome. Furthermore, this group of infants were unable to produce significant concentrations of IL-1beta.

Increased plasma markers of inflammation and endothelial dysfunction and their association with microvascular complications in Type 1 diabetic patients without clinically manifest macroangiopathy

AIMS

To evaluate whether plasma biomarkers of inflammation and endothelial dysfunction differed in Type 1 diabetic patients as compared with those in non-diabetic subjects, and to examine the association of these biomarkers with early stages of microvascular complications.

METHODS

Plasma biomarkers of inflammation [fibrinogen, hs-C-reactive protein (hs-CRP)] and endothelial dysfunction [von Willebrand factor (v-WF), intercellular adhesion molecule-1, plasminogen activator inhibitor-1 (PAI-1) activity] were measured in 88 non-smoking young patients with Type 1 diabetes without clinical macrovascular disease and in 40 healthy controls.

RESULTS

Plasma levels of hs-CRP, fibrinogen, v-WF, soluble intracellular adhesion molecule-1 (sICAM-1) and PAI-1 activity were markedly higher (P < 0.01 or less) in Type 1 diabetic patients than in healthy controls; these results were essentially unchanged when healthy controls were compared with patients without complications. After stratification by microvascular complication status, plasma biomarkers of inflammation and endothelial dysfunction were significantly increased in those with more advanced disease compared with those with early complications or without complications, respectively. However, while the significant differences in these biomarkers were little affected by adjustment for sex, age, BMI and blood pressure values, they were totally abolished after additional adjustment for diabetes duration and glycaemic control.

CONCLUSIONS

These results indicate that in Type 1 diabetes there is a subclinical, chronic inflammation which is, at least partly, independent of clinically manifest macro- and microvascular complications, smoking or other traditional cardiovascular risk factors; this subclinical inflammation is closely correlated to the magnitude and duration of hyperglycaemia.

Inhibition of tumor necrosis factor-alpha-induced RANTES secretion by alkaline protease in A549 cells

Pseudomonas aeruginosa is a gram-negative bacterium that is an opportunistic pathogen in patients with cystic fibrosis and in immunocompromised hosts. This bacterium produces a variety of proteolytic enzymes, including alkaline protease (AP), which has multiple biological effects. This study investigated the effects of AP on the A549 pulmonary epithelial cell line. Results demonstrate that AP inhibited tumor necrosis factor (TNF)-alpha-induced RANTES gene expression and secretion in a concentration-dependent manner. The TNF-alpha-induced RANTES gene expression and secretion was attenuated with a neutralizing monoclonal antibody directed against the TNF receptor type 1 (TNFR1). Conversely, a neutralizing monoclonal antibody directed against TNF receptor type II had no effect, suggesting that these events were regulated through the TNFR1 receptor. In addition, we observed that soluble TNF receptor type 1 (sTNFR1) levels were significantly increased in culture supernatants of AP-treated cells in a concentration-dependent manner. Finally, membrane-associated TNFR1 was decreased after AP exposures. In these studies, the enzymatically inactive form of AP had no effect on TNF-alpha-induced RANTES secretion, shedding of sTNFR1, or membrane-associated TNFR1. These results demonstrate that AP stimulates shedding of cell-surface TNFR1, resulting in an increase in sTNFR1. Consequently, these events decrease the cells' ability to stimulate RANTES gene expression and secretion through TNFR1.

Immunocytochemical localization of TNF type 1 and type 2 receptors in the rat spinal cord

Tumor necrosis factor-alpha (TNF-alpha) is secreted in numerous pathophysiological situations by a variety of cell types. Tactile hypersensitivity (allodynia) is one component of a constellation of "illness behaviors" triggered by TNF-alpha. TNF-alpha is also implicated in neuropathic pain after peripheral nerve injury and apoptosis after spinal cord injury (SCI). It is possible that SCI, illness- and peripheral injury-induced hypersensitivity may share a similar spinal mediated etiology. These studies identify the locus of type-1 TNF (TNFR1 or p55) and type-2 TNF (TNFR2 or p75) receptors within the spinal cord. At all spinal levels, TNFR1 receptor immunoreactivity (TNFR1-ir) was constitutively expressed on cells and afferent fibers within the dorsal root ganglia, afferent fibers of the dorsal root, dorsal root entry zone (REZ) and within lamina I and II of the dorsal horn. Unilateral dorsal rhizotomy eliminated the characteristic pattern of TNFR1-ir at the rhizotomized REZ. In contrast, TNFR2-ir was consistently absent from dorsal root fibers and the region of the root entry zone. Consistent with our previous report, medullary afferent fibers in the solitary tract and spinal trigeminal tract labelled for TNF1-ir, but did not express TNFR2-ir. The presence TNFR1-ir on dorsal horn afferents, suggests that TNF-alpha may be a mechanism responsible for tactile hypersensitivity during illness. The presence of TNFR1 receptors, and perhaps their long-term activation or plasticity, may also play a critical role in the chronic allodynia and hyperreflexia observed after SCI or peripheral nerve damage.

Cytokines and soluble tumour necrosis factor I receptor levels during pretransplant conditioning in allogeneic stem-cell transplantation

The inflammatory response induced by the conditioning regime may be related to the outcome in allogeneic stem-cell transplantation (SCT). However, previous statements concerning the prognostic significance of cytokine measurements during conditioning have not been conclusive. We investigated a broad range of cytokines in plasma samples drawn daily immediately before start of pretransplant conditioning and during the conditioning. The presented data indicate that single-day measurements of inflammatory cytokines during conditioning may lead to unreliable conclusions concerning their prognostic significance. However, serial quantitation of soluble tumour necrosis factor receptor I (sTNFRI) is more likely to reflect the degree of inflammatory activation induced by pretransplant conditioning.

Inhibition of tumor necrosis factor (TNF) signal transduction by the adenovirus group C RID complex involves downregulation of surface levels of TNF receptor 1

Adenoviruses employ multiple genes to inhibit the host antiviral responses. There is increasing evidence that these immunoregulatory genes may function either during lytic or latent infection. Adenovirus early transcription region 3 (E3) encodes at least seven proteins, five of which block the acquired or innate immune response. Previous findings from this laboratory demonstrated that the E3 proteins 10.4K and 14.5K, which form a complex in the plasma membrane, inhibit tumor necrosis factor (TNF)-induced activation of NF-kappaB and the synthesis of chemokines. To determine the mechanism of inhibition of these pathways by the adenovirus E3 10.4K/14.5K proteins, we have examined the effects of this viral complex on the inhibition of AP-1 and NF-kappaB activation by TNF and found a reduction in assembly of the TNF receptor 1 (TNFR1) signaling complex at the plasma membrane accompanied by downregulation of surface levels of TNFR1.

Maternal soluble tumour necrosis factor receptor type 2 (sTNFR2) and adiponectin are both related to blood pressure during gestation and infant's birthweight

OBJECTIVE

Tumour necrosis factor alpha (TNF-alpha) and adiponectin are strongly related to insulin sensitivity; insulin resistance of pregnancy is a major determinant of infant's birthweight. We aimed to study the contributions of maternal serum concentrations of soluble TNF-alpha receptors (sTNFR1 and sTNFR2) and adiponectin to infant's birthweight.

DESIGN

Cross-sectional, hospital-based study of insulin sensitivity during gestation.

PATIENTS

Fifty-one healthy women with uncomplicated pregnancy and delivery (except for elective Caesarian section) and their healthy newborn infants. measurements Maternal blood levels of glucose, insulin, glycosylated haemaglobin (HbA1c), sTNFR1, sTNFR2 and adiponectin at delivery; cord-blood levels of sTNFR1, sTNFR2 and adiponectin.

RESULTS

At delivery, maternal sTNFR2 correlated with systolic blood pressure (SBP; r = 0.38, P = 0.005). In multiple regression analyses, SBP and HbA1c were independent predictors of sTNFR2, explaining 18 and 7% of its variance, respectively; insulin resistance index (HOMA-IR), body mass index at delivery and SBP were independent predictors of adiponectin, explaining 15, 8 and 7% of its variance, respectively. Both maternal sTNFR2 and SBP were negatively correlated with infant's birthweight (r = -0.28, P = 0.04 and r = -0.36, P = 0.01 respectively, adjusted for sex and gestational age). In multivariate regression analyses, infant's sex and either maternal sTNFR2 or adiponectin were independent predictors of infant's birthweight, each explaining between 6 and 9% of birthweight variance. Further addition of maternal SBP to these models revealed that this variable was the main predictor of infant's birthweight, explaining 13% of its variance.

CONCLUSIONS

Maternal sTNFR2 and adiponectin are independently related to both maternal blood pressure and infant's birthweight in uncomplicated pregnancy. The contributions of the TNF-alpha system and adiponectin to hypertensive disorders of pregnancy and fetal growth merit further studies.