Objective To investigate the expression profiles and their clinical significance of TRAIL receptors (TRAILR) in human hepatocellular carcinoma (HCC). Methods The expression profiles of TRAILR were determined in 60 s...Objective To investigate the expression profiles and their clinical significance of TRAIL receptors (TRAILR) in human hepatocellular carcinoma (HCC). Methods The expression profiles of TRAILR were determined in 60 samples from hepatocellular carcinoma, 20 from normal liver tissue and two HCC cell lines HepG2, SMMC-7721 by in situ hybridization. Results Both DR4 and DR5 were present in all HCC tissues as well as normal hepatic tissues. In contrast, 54 HCC tissues did not express DcR1 and 25 did not express DcR2. But both DcR were detectable in all of the normal liver tissues. The expression patterns of DR and DcR in HCC samples (higher DR expression level and lower DcR expression level) were quite different from those in normal tissue. DR5, DR4, and DcR2 expressed in both cell lines, while no DcR1 expression was detected. The expression level of DR was correlated with HCC differentiation and stage. The weaker expression was more commonly found in HCC with poor differentiation and late stage, while the stronger expression was more common in HCC with middle to high-differentiation and early stage. No relationship was found between DR and gender, age, negative or positive HBsAg, tumor size, grade or metastasis. Multidrug resistance cell lines expressed lower level DR. Conclusion TRAILR expression was prevalent and discrepancy of receptor types was exited in HCC. Loss of DcR1 may contribute for TRAIL therapy for HCC. Key words TRAILR - apoptosis - hepatocellular carcinoma Supported by the Major Fundation of Ministry of Health, NO. 2001–2003展开更多
Objective To investigate the role of TNF receptor-associated factor 2 (TRAF-2) and TRAF6 in CD40-induced nuclear factor-κB (NF-κB) signaling pathway and whether CD40 signaling requires TRAF2. Methods Human B cell li...Objective To investigate the role of TNF receptor-associated factor 2 (TRAF-2) and TRAF6 in CD40-induced nuclear factor-κB (NF-κB) signaling pathway and whether CD40 signaling requires TRAF2. Methods Human B cell lines were transfected with plasmids expressing wild type TRAF2 or dominant negative TRAF2,TRAF2-shRNA,or TRAF6-shRNA. The activation of NF-κB was detected by Western blot,kinase assay,transfactor enzyme-linked immunosorbent assay (ELISA),and fluorescence resonance energy transfer (FRET). Analysis of the role of TRAF-2 and TRAF-6 in CD40-mediated NF-κB activity was examined following stimulation with recombinant CD154. Results TRAF2 induced activity of IκB-kinases (IKKα,IKKi/ε),phosphorylation of IκBα,as well as nuclear translocation and phosphorylation of p65/RelA. In contrast,TRAF6 strongly induced NF-κB activation and nuclear translocation of p65 as well as p50 and c-Rel. Engagement of CD154-induced nuclear translocation of p65 was inhibited by a TRAF6-shRNA,but conversely was enhanced by a TRAF2-shRNA. Examination of direct interactions between CD40 and TRAFs by FRET documented that both TRAF2 and TRAF6 directly interacted with CD40. However,the two TRAFs competed for CD40 binding. Conclusions These results indicate that TRAF2 can signal in human B cells,but it is not essential for CD40-mediated NF-κB activation. Moreover,TRAF2 can compete with TRAF6 for CD40 binding,and thereby limit the capacity of CD40 engagement to induce NF-κB activation.展开更多
Tripartite motif containing 22 （TRIM22）, a member of the TRIM/RBCC family, has been reported to activate the nuclear factor-kappa B （NF-kB） pathway in unstimulated macrophage cell lines, but the detailed mechanism...Tripartite motif containing 22 （TRIM22）, a member of the TRIM/RBCC family, has been reported to activate the nuclear factor-kappa B （NF-kB） pathway in unstimulated macrophage cell lines, but the detailed mechanisms governing this activation remains unclear. We investigated this mechanism in HEK293T cells. We found that overexpression of TRIM22 could activate the NF-kB pathway and conversely, could inhibit the tumor necrosis factor receptor-associated factor 6 （TRAF6）-stimulated NF-kB pathway in HEK293T cells. Further experiments showed that TRIM22 could decrease the self-ubiquitination of TRAF6, and interact with and degrade transforming growth factor-13 activated kinase 1 binding protein 2 （TAB2）, and that these effects could be partially rescued by a TRIM22 RING domain deletion mutant. Collectively, our data indicate that overexpression of TRIM22 may negatively regulate the TRAF6-stimulated NF-rd3 pathway by interacting with and degrading TAB2.展开更多
The use of anti-tumor necrosis factor-α therapy for inflammatory bowel disease represents the most important advance in the care of these patients since the publication of the National Co-operative Crohn＇s disease s...The use of anti-tumor necrosis factor-α therapy for inflammatory bowel disease represents the most important advance in the care of these patients since the publication of the National Co-operative Crohn＇s disease study thirty years ago. The recommendations of numerous consensus groups worldwide are now supported by a wealth of clinical trials and several meta-analyses. In general, it is suggested that tumor necrosis factor-c~ blockers （TNFBs） are indicated （1） for persons with moderately-severe Crohn＇s disease or ulcerative colitis （UC） who have failed two or more causes of glucocorticosteroids and an acceptably long cause （8 wk to 12 wk） of an immune modulator such as azathioprine or methotrexate; （2） non-responsive perianal disease; and （3） severe UC not responding to a 3-d to 5-d course of steroids. Once TNFBs have been introduced and the patient is responsive, therapy given by the IV and SC rate must be continued. It remains open to definitive evidence if concomitant immune modulators are required with TNFB maintenance ther- apy, and when or if TNFB may be weaned and discon- tinued. The supportive evidence from a single study on the role of early versus later introduction of TNFB in the course of a patient＇s illness needs to be confirmed. The risk/benefit profile of TNFB appears to be accept- able as long as the patient is immunized and tested for tuberculosis and viral hepatitis before the initiation of TNFB, and as long as the long-term adverse effects on the development of lymphoma and other tumors do not prone to be problematic. Because the rates of ben- efits to TNFB are modest from a population perspec- tive and the cost of therapy is very high, the ultimate application of use of TNFBs will likely be established by cost/benefit studies.展开更多
In the present article, we report that DR4 or DR5 overexpression dramatically activates the release of the inflammatory cytokines IL-8, TNF-α, CCL20, MIP-2 and MIP-1β in an NF-κB-dependent manner in 293T, MDA-MB-23...In the present article, we report that DR4 or DR5 overexpression dramatically activates the release of the inflammatory cytokines IL-8, TNF-α, CCL20, MIP-2 and MIP-1β in an NF-κB-dependent manner in 293T, MDA-MB-231 and HCT-116 cells. We showed that death receptor-mediated signals were extracellular domain-independent, whereas the effect of overexpression of the DR4 intracellular domain was much less potent. The TRADD-TRAF2-NIK- IKKα/β signaling cascade, which plays an essential role in TNF-induced NF-κB activation, was found to be involved in tumor necrosis factor-related apoptosis-inducing ligand （TRAIL） receptor-mediated signal transduction. The FADD-caspase signaling pathway, which has been reported to be mostly related to apoptosis, was identified as being essential for DR4 or DR5 overexpression-mediated NF-κB activation and cytokine secretion and crosstalks with the TRADD-TRAF2-NIK-IKKα/β signaling cascade. Furthermore, a DR5 agonistic antibody （AD5-10） triggered the inflammatory cytokine release. These data, together with previous reports, provide strong evidence that TRAIL and TRAIL receptors play an important role in inflammation.展开更多
TRAIL, tumor necrosis factor-related apoptosis-inducing ligand, is a member of the TNF family of proteins.Tumour cells were initially found to have increased sensitivity to TRAIL compared with normal cells, raising ho...TRAIL, tumor necrosis factor-related apoptosis-inducing ligand, is a member of the TNF family of proteins.Tumour cells were initially found to have increased sensitivity to TRAIL compared with normal cells, raising hopes thatTRAIL would prove useful as an anti-tumor agent. The production of reliable monoclonal antibodies against TRAIL andits receptors that can stain fixed specimens will allow a thorough analysis of their expression on normal and malignanttissues. Here we report the generation of monoclonal antibodies against TRAIL and its four membrane-bound receptors(TR1–4), which have been used to stain a range of normal and malignant cells, as routinely fixed specimens. Low levelsof TRAIL expression were found to be limited mostly to smooth muscle in lung and spleen as well as glial cells in thecerebellum and follicular cells in the thyroid. Expression of the TRAIL decoy receptors (TR3 and 4) was not aswidespread as indicated by Northern blotting, suggesting that they may be less important for the control of TRAILcytotoxicity than previously thought. TR1 and TR2 expression increases significantly in a number of malignant tissues,but in some common malignancies their expression was low, or patchy, which may limit the therapeutic role of TRAIL.Taken together, we have a panel of monoclonal antibodies that will allow a better assessment of the normal role ofTRAIL and allow assessment of biopsy material, possibly allowing the identification of tumors that may be amenable toTRAIL therapy.展开更多
Mixed lineage kinase 3 （MLK3） is a mitogen-activated protein kinase kinase kinase that is activated by tumor necrosis factor-α （TNF-α） and specifically activates c-Jun N-terminal kinase （JNK） on TNF-a stimulat...Mixed lineage kinase 3 （MLK3） is a mitogen-activated protein kinase kinase kinase that is activated by tumor necrosis factor-α （TNF-α） and specifically activates c-Jun N-terminal kinase （JNK） on TNF-a stimulation. The mecha- nism by which TNF-α activates MLK3 is still not known. TNF receptor-associated factors （TRAFs） are adapter molecules that are recruited to cytoplasmic end of TNF receptor and mediate the downstream signaling, including activation of JNK. Here, we report that MLK3 associates with TRAF2, TRAF5 and TRAF6; however only TRAF2 can significantly induce the kinase activity of MLK3. The interaction domain of TRAF2 maps to the TRAF domain and for MLK3 to its C-terminal half （amino acids 511-847）. Endogenous TRAF2 and MLK3 associate with each other in response to TNF-α treatment in a time-dependent manner. The association between MLK3 and TRAF2 mediates MLK3 activation and competition with the TRAF2 deletion mutant that binds to MLK3 attenuates MLK3 kinase activity in a dose-dependent manner, on TNF-α treatment. Furthermore the downstream target of MLK3, JNK was activated by TNF-α in a TRAF2-dependent manner. Hence, our data show that the direct interaction between TRAF2 and MLK3 is required for TNF-α-induced activation of MLK3 and its downstream target, JNK.展开更多
Identification of tumour necrosis factor apoptosis inducing ligand (TRAIL), a TNF family ligand, sparked a torrent of research, following an initial observation that it could kill tumour cells, but spare normal cells....Identification of tumour necrosis factor apoptosis inducing ligand (TRAIL), a TNF family ligand, sparked a torrent of research, following an initial observation that it could kill tumour cells, but spare normal cells. Almost a decade after its discovery, and with five known receptors, the true physiological role of TRAIL is still debated and its anti-tumorigenic properties limited by potential toxicity. This review takes a comprehensive look at the story of this enigmatic ligand, addressing its remaining potential as a therapeutic and providing an overview of the TRAIL receptors themselves.展开更多
Hepatitis C virus (HCV) infection is an important risk factor for insulin resistance (IR). The latter is the pathogenic foundation underlying metabolic syndrome, steatosis and cirrhosis, and possibly hepatocellular ca...Hepatitis C virus (HCV) infection is an important risk factor for insulin resistance (IR). The latter is the pathogenic foundation underlying metabolic syndrome, steatosis and cirrhosis, and possibly hepatocellular carcinoma (HCC). The interplay between genetic and environmental risk factors ultimately leads to the development of IR. Obesity is considered a major risk factor, with dysregulation of levels of secreted adipokines from distended adipose tissue playing a major role in IR. HCV-induced IR may be due to the HCV core protein inducing proteasomal degradation of insulin receptor substrates 1 and 2, blocking intracellular insulin signaling. The latter is mediated by increased levels of both tumour necrosis factor-α (TNF-α) and suppressor of cytokine signaling 3 (SOC-3). IR, through different mechanisms, plays a role in the development of steatosis and its progression to steatohepatitis, cirrhosis and even HCC. In addition, IR has a role in impairing TNF signaling cascade, which in turn blocks STAT-1 translocation and interferon stimulated genes production avoiding the antiviral effect of interferon.展开更多
AIM: To determine the expression statuses of tumor necrosis factor (TNF)-α, its receptors (TNF-R) and downstream effector molecules in human colorectal adenomas. METHODS: We measured the serum concentrations of TNF-...AIM: To determine the expression statuses of tumor necrosis factor (TNF)-α, its receptors (TNF-R) and downstream effector molecules in human colorectal adenomas. METHODS: We measured the serum concentrations of TNF-α and its receptors in 62 colorectal adenoma patients and 34 healthy controls. The protein expression of TNF-α, TNF-R1, TNF-R2 and downstream signals of the TNF receptors, such as c-Jun N-terminal kinase (JNK), nuclear factor-κ B and caspase-3, were also investigated in human colorectal adenomas and in normal colorectal mucosal tissues by immunohistochemistry. Immunofluorescence confocal microscopy was used to investigate the consistency of expression of TNF-R1 and phospho-JNK (p-JNK). RESULTS: The serum levels of soluble TNF-R1 (sTNF-R1) in adenoma patients were significantly higher than in the control group (3.67 ± 0.86 ng/mL vs 1.57 ± 0.72 ng/mL, P < 0.001). Receiver operating characteristic analysis revealed the high diagnostic sensitivity of TNF-R1 measurements (AUC was 0.928) for the diagnosis of adenoma, and the best cut-off level of TNF-R1 was 2.08 ng/mL, with a sensitivity of 93.4% and a specificity of 82.4%. There were no significant differences in the serum levels of TNF-α or sTNF-R2 between the two groups. Immunohistochemistry showed high levels of TNF-R1 and p-JNK expression in the epithelial cells of adenomas. Furthermore, a high incidence of co-localization of TNF-R1 and p-JNK was identified in adenoma tissue. CONCLUSION: TNF-R1 may be a promising biomarker of colorectal adenoma, and it may also play an important role in the very early stages of colorectal carcinogenesis.展开更多
OBJECTIVE: To examine whether electroacupuncture(EA) treatment inhibited cell apoptosis of intervertebral annulus fibrosis(AF) via tumor necrosis factor-α(TNF-α)-tumor necrosis factor receptor 1(TNFR1)-caspase-8 and...OBJECTIVE: To examine whether electroacupuncture(EA) treatment inhibited cell apoptosis of intervertebral annulus fibrosis(AF) via tumor necrosis factor-α(TNF-α)-tumor necrosis factor receptor 1(TNFR1)-caspase-8 and integrin β1/Akt signaling pathways in a rat model of cervical intervertebral disc degeneration caused by unbalanced dynamic and static forces.METHODS: Thirty-two Sprague-Dawley rats were included in this study, of which 24 rats underwent surgery to induce cervical intervertebral disc degeneration, while eight rats received EA treatment at Dazhui(GV 14). Immunohistochemical staining was used to detect TNF-α, TNFR1, and caspase-8Apoptosis of AF cells was examined with terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling(TUNEL) staining. The m RNA and protein expression levels of integrin β1 andAkt were evaluated with real-time polymerase chain reaction and western blot analysis, respectively.RESULTS: Treatment with EA decreased TUNEL-positive AF cells and lowered TNF-α, TNFR1 and caspase-8 positive cells compared with control groups. EA treatment also increased integrin β1and Akt m RNA and protein levels compared with controls.CONCLUSION: Treatment with EA inhibits AF cell apoptosis through suppression of the TNF-α-TNFR1-caspase-8 signal pathway and increases the expression of integrin β1 and Akt. EA may be a good alternative therapy for treating cervical spondylosis.展开更多
Liver transplantation is an established therapy for end-stage liver diseases. Graft rejection occurs unless the recipient receives immunosuppression after transplantation. This study aimed to explore the mechanism of ...Liver transplantation is an established therapy for end-stage liver diseases. Graft rejection occurs unless the recipient receives immunosuppression after transplantation. This study aimed to explore the mechanism of acute rejection of liver allografts in rats pre-treated with total body irradiation to eliminate passenger lymphocytes and to define the role of CD4＋CD25＋ regulatory T cells in the induction of immunotolerance in the recipient. Male Lewis rats were used as donors and male DA rats were re- cipients. Rats were randomly assigned to the following four groups： control group, homogeneity liver transplantation group, idio-immunotolerance group and acute rejection group. After transplantation, the survival time of each group, serum alanine aminotransferase, total bilirubin levels, number of Foxp3＋CD4＋CD25＋ regulatory T cells, expression of glucocorticoid-induced tumor necrosis factor receptor on T cell subgroups, histopathology of the hepatic graft and spleen cytotoxic T lymphocyte lytic activity were measured. In the acute rejection group, where donors were preconditioned with total body in＇adiation before liver transplantation, all recipients died between day 17 and day 21. On day 14, serum alanine aminotransferase increased signifi- cantly to （459.2±76.9） U L^- 1, total bilirubin increased to （124.1±33.7） μmol L-1 （P〈0.05） and the ratio of Foxp3＋CD4＋CD25＋ regulatory T cells decreased significantly to 1.50%±0.50% （P〈0.05） compared with the other groups. Analysis of the T cell subpopulations in the acute rejection group varied from the other groups. Histological analysis showed typical changes of acute rejection in the acute rejection group only. Preconditioning of the donors with total body irradiation eliminated passenger lymphocytes of the liver graft, and thus affected the course of tolerance and induced acute rejection after liver transplantation.展开更多
The tumor-promoting arm of transforming growth factor beta(TGF-β)receptor signaling contributes to advanced cancer progression and is considered a master regulator of breast cancer metastasis.In mammals,there are six...The tumor-promoting arm of transforming growth factor beta(TGF-β)receptor signaling contributes to advanced cancer progression and is considered a master regulator of breast cancer metastasis.In mammals,there are six distinct members in the tumor-necrosis factor receptor(TNFR)-associated factor(TRAF)family(TRAF1–TRAF6),with the function of TRAF4 not being extensively studied in the past decade.Although numerous studies have suggested that there is elevated TRAF4 expression in human cancer,it is still unknown in which oncogenic pathway TRAF4 is mainly implicated.This review highlights TGF-β-induced SMAD-dependent signaling and non-SMAD signaling as the major pathways regulated by TRAF4 involved in breast cancer metastasis.展开更多
Sphingosine-1-phosphate（S1P） is a bioactive lipid messenger in the cells that regulate gene expression and NF-κB signal pathway through unknown mechanisms.Recently,Cheng Luo,associate professor of DDDC in Shanghai ...Sphingosine-1-phosphate（S1P） is a bioactive lipid messenger in the cells that regulate gene expression and NF-κB signal pathway through unknown mechanisms.Recently,Cheng Luo,associate professor of DDDC in Shanghai Institute of Materia Medica,whose project was funded by the National Natural Science Foundation of China,joined in a research team led by Professor Sarah Spiegel of Virginia Commonwealth University.The team continuously made significant breakthroughs in understanding the regulation mechanism of Sphingosine-1- Phosphate.In September 2009,in a paper published on SCIENCE magazine（Science 2009, 325：1254-7）,they firstly demonstrated that S1P is a physiologically important regulator of histone deacetylases（HDACs）,HDACs are direct intracellular targets of S1P.Furthermore,they identified the mechanism that S1P regulates gene expression through regulating the activity of HDACs.In June 24th,2010,in another paper to be published on NATURE magazine（Nature 2010,June 24th,advance online publication,（doi：10.1038/ nature09128）） which reports the regulation of NF-κB signaling pathway by S1P.They demonstrate that S1P is the missing cofactor for TRAF2（tumour-necrosis factor receptor-associated factor 2） and indicate a new paradigm for the regulation of lysine-63- linked poly-ubiquitination.The study also highlight the key role of SphK1 and its product S1P in TNF-αsignalling and the canonical NF-κB activation pathway, and then play crucial role in inflammatory,antiapoptotic and immune processes.The identification of new mechanisms fay which S1P regulates gene expression and TNF and NF-κB signaling pathway will light up the road to develop novel inhibitors that might be useful for treatment of cancer and in- flammatory diseases.展开更多
文摘Objective To investigate the expression profiles and their clinical significance of TRAIL receptors (TRAILR) in human hepatocellular carcinoma (HCC). Methods The expression profiles of TRAILR were determined in 60 samples from hepatocellular carcinoma, 20 from normal liver tissue and two HCC cell lines HepG2, SMMC-7721 by in situ hybridization. Results Both DR4 and DR5 were present in all HCC tissues as well as normal hepatic tissues. In contrast, 54 HCC tissues did not express DcR1 and 25 did not express DcR2. But both DcR were detectable in all of the normal liver tissues. The expression patterns of DR and DcR in HCC samples (higher DR expression level and lower DcR expression level) were quite different from those in normal tissue. DR5, DR4, and DcR2 expressed in both cell lines, while no DcR1 expression was detected. The expression level of DR was correlated with HCC differentiation and stage. The weaker expression was more commonly found in HCC with poor differentiation and late stage, while the stronger expression was more common in HCC with middle to high-differentiation and early stage. No relationship was found between DR and gender, age, negative or positive HBsAg, tumor size, grade or metastasis. Multidrug resistance cell lines expressed lower level DR. Conclusion TRAILR expression was prevalent and discrepancy of receptor types was exited in HCC. Loss of DcR1 may contribute for TRAIL therapy for HCC. Key words TRAILR - apoptosis - hepatocellular carcinoma Supported by the Major Fundation of Ministry of Health, NO. 2001–2003
基金Supported by Key Projects of the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period (2008-BAI59B02)
文摘Objective To investigate the role of TNF receptor-associated factor 2 (TRAF-2) and TRAF6 in CD40-induced nuclear factor-κB (NF-κB) signaling pathway and whether CD40 signaling requires TRAF2. Methods Human B cell lines were transfected with plasmids expressing wild type TRAF2 or dominant negative TRAF2,TRAF2-shRNA,or TRAF6-shRNA. The activation of NF-κB was detected by Western blot,kinase assay,transfactor enzyme-linked immunosorbent assay (ELISA),and fluorescence resonance energy transfer (FRET). Analysis of the role of TRAF-2 and TRAF-6 in CD40-mediated NF-κB activity was examined following stimulation with recombinant CD154. Results TRAF2 induced activity of IκB-kinases (IKKα,IKKi/ε),phosphorylation of IκBα,as well as nuclear translocation and phosphorylation of p65/RelA. In contrast,TRAF6 strongly induced NF-κB activation and nuclear translocation of p65 as well as p50 and c-Rel. Engagement of CD154-induced nuclear translocation of p65 was inhibited by a TRAF6-shRNA,but conversely was enhanced by a TRAF2-shRNA. Examination of direct interactions between CD40 and TRAFs by FRET documented that both TRAF2 and TRAF6 directly interacted with CD40. However,the two TRAFs competed for CD40 binding. Conclusions These results indicate that TRAF2 can signal in human B cells,but it is not essential for CD40-mediated NF-κB activation. Moreover,TRAF2 can compete with TRAF6 for CD40 binding,and thereby limit the capacity of CD40 engagement to induce NF-κB activation.
基金supported by a grant from the Key Projects in the National Science & Technology Pillar Program during the twelfth Five-Year Plan Period of China (2012ZX10001006-002)grants from the International Science & Technology Cooperation Program of China (2011DFA31030)Deutsche Forschungsgemeinschaft (SFB/Transregio TRR60)and Key Laboratory on Emerging Infectious Diseases and Biosafety in Wuhan
文摘Tripartite motif containing 22 （TRIM22）, a member of the TRIM/RBCC family, has been reported to activate the nuclear factor-kappa B （NF-kB） pathway in unstimulated macrophage cell lines, but the detailed mechanisms governing this activation remains unclear. We investigated this mechanism in HEK293T cells. We found that overexpression of TRIM22 could activate the NF-kB pathway and conversely, could inhibit the tumor necrosis factor receptor-associated factor 6 （TRAF6）-stimulated NF-kB pathway in HEK293T cells. Further experiments showed that TRIM22 could decrease the self-ubiquitination of TRAF6, and interact with and degrade transforming growth factor-13 activated kinase 1 binding protein 2 （TAB2）, and that these effects could be partially rescued by a TRIM22 RING domain deletion mutant. Collectively, our data indicate that overexpression of TRIM22 may negatively regulate the TRAF6-stimulated NF-rd3 pathway by interacting with and degrading TAB2.
文摘The use of anti-tumor necrosis factor-α therapy for inflammatory bowel disease represents the most important advance in the care of these patients since the publication of the National Co-operative Crohn＇s disease study thirty years ago. The recommendations of numerous consensus groups worldwide are now supported by a wealth of clinical trials and several meta-analyses. In general, it is suggested that tumor necrosis factor-c~ blockers （TNFBs） are indicated （1） for persons with moderately-severe Crohn＇s disease or ulcerative colitis （UC） who have failed two or more causes of glucocorticosteroids and an acceptably long cause （8 wk to 12 wk） of an immune modulator such as azathioprine or methotrexate; （2） non-responsive perianal disease; and （3） severe UC not responding to a 3-d to 5-d course of steroids. Once TNFBs have been introduced and the patient is responsive, therapy given by the IV and SC rate must be continued. It remains open to definitive evidence if concomitant immune modulators are required with TNFB maintenance ther- apy, and when or if TNFB may be weaned and discon- tinued. The supportive evidence from a single study on the role of early versus later introduction of TNFB in the course of a patient＇s illness needs to be confirmed. The risk/benefit profile of TNFB appears to be accept- able as long as the patient is immunized and tested for tuberculosis and viral hepatitis before the initiation of TNFB, and as long as the long-term adverse effects on the development of lymphoma and other tumors do not prone to be problematic. Because the rates of ben- efits to TNFB are modest from a population perspec- tive and the cost of therapy is very high, the ultimate application of use of TNFBs will likely be established by cost/benefit studies.
基金We thank Drs Hongbing Shu （Wuhan University, China）, Jiandong Li （University of Rochester Medical Center, USA）, Andrew Thorbum （University of Colorado Comprehensive Cancer Center, USA） and Andreas Strasser （The Walter and Eliza Hall Institute of Medical Research, Australia） for the generous gifts of the constructs. This work was partially supported by the National Natural Science Foundation of China （Grants 30571687 and 30721063） and the State Key Basic Research Program of China （Grant 2007CB507404）.
文摘In the present article, we report that DR4 or DR5 overexpression dramatically activates the release of the inflammatory cytokines IL-8, TNF-α, CCL20, MIP-2 and MIP-1β in an NF-κB-dependent manner in 293T, MDA-MB-231 and HCT-116 cells. We showed that death receptor-mediated signals were extracellular domain-independent, whereas the effect of overexpression of the DR4 intracellular domain was much less potent. The TRADD-TRAF2-NIK- IKKα/β signaling cascade, which plays an essential role in TNF-induced NF-κB activation, was found to be involved in tumor necrosis factor-related apoptosis-inducing ligand （TRAIL） receptor-mediated signal transduction. The FADD-caspase signaling pathway, which has been reported to be mostly related to apoptosis, was identified as being essential for DR4 or DR5 overexpression-mediated NF-κB activation and cytokine secretion and crosstalks with the TRADD-TRAF2-NIK-IKKα/β signaling cascade. Furthermore, a DR5 agonistic antibody （AD5-10） triggered the inflammatory cytokine release. These data, together with previous reports, provide strong evidence that TRAIL and TRAIL receptors play an important role in inflammation.
文摘TRAIL, tumor necrosis factor-related apoptosis-inducing ligand, is a member of the TNF family of proteins.Tumour cells were initially found to have increased sensitivity to TRAIL compared with normal cells, raising hopes thatTRAIL would prove useful as an anti-tumor agent. The production of reliable monoclonal antibodies against TRAIL andits receptors that can stain fixed specimens will allow a thorough analysis of their expression on normal and malignanttissues. Here we report the generation of monoclonal antibodies against TRAIL and its four membrane-bound receptors(TR1–4), which have been used to stain a range of normal and malignant cells, as routinely fixed specimens. Low levelsof TRAIL expression were found to be limited mostly to smooth muscle in lung and spleen as well as glial cells in thecerebellum and follicular cells in the thyroid. Expression of the TRAIL decoy receptors (TR3 and 4) was not aswidespread as indicated by Northern blotting, suggesting that they may be less important for the control of TRAILcytotoxicity than previously thought. TR1 and TR2 expression increases significantly in a number of malignant tissues,but in some common malignancies their expression was low, or patchy, which may limit the therapeutic role of TRAIL.Taken together, we have a panel of monoclonal antibodies that will allow a better assessment of the normal role ofTRAIL and allow assessment of biopsy material, possibly allowing the identification of tumors that may be amenable toTRAIL therapy.
文摘Mixed lineage kinase 3 （MLK3） is a mitogen-activated protein kinase kinase kinase that is activated by tumor necrosis factor-α （TNF-α） and specifically activates c-Jun N-terminal kinase （JNK） on TNF-a stimulation. The mecha- nism by which TNF-α activates MLK3 is still not known. TNF receptor-associated factors （TRAFs） are adapter molecules that are recruited to cytoplasmic end of TNF receptor and mediate the downstream signaling, including activation of JNK. Here, we report that MLK3 associates with TRAF2, TRAF5 and TRAF6; however only TRAF2 can significantly induce the kinase activity of MLK3. The interaction domain of TRAF2 maps to the TRAF domain and for MLK3 to its C-terminal half （amino acids 511-847）. Endogenous TRAF2 and MLK3 associate with each other in response to TNF-α treatment in a time-dependent manner. The association between MLK3 and TRAF2 mediates MLK3 activation and competition with the TRAF2 deletion mutant that binds to MLK3 attenuates MLK3 kinase activity in a dose-dependent manner, on TNF-α treatment. Furthermore the downstream target of MLK3, JNK was activated by TNF-α in a TRAF2-dependent manner. Hence, our data show that the direct interaction between TRAF2 and MLK3 is required for TNF-α-induced activation of MLK3 and its downstream target, JNK.
文摘Identification of tumour necrosis factor apoptosis inducing ligand (TRAIL), a TNF family ligand, sparked a torrent of research, following an initial observation that it could kill tumour cells, but spare normal cells. Almost a decade after its discovery, and with five known receptors, the true physiological role of TRAIL is still debated and its anti-tumorigenic properties limited by potential toxicity. This review takes a comprehensive look at the story of this enigmatic ligand, addressing its remaining potential as a therapeutic and providing an overview of the TRAIL receptors themselves.
文摘Hepatitis C virus (HCV) infection is an important risk factor for insulin resistance (IR). The latter is the pathogenic foundation underlying metabolic syndrome, steatosis and cirrhosis, and possibly hepatocellular carcinoma (HCC). The interplay between genetic and environmental risk factors ultimately leads to the development of IR. Obesity is considered a major risk factor, with dysregulation of levels of secreted adipokines from distended adipose tissue playing a major role in IR. HCV-induced IR may be due to the HCV core protein inducing proteasomal degradation of insulin receptor substrates 1 and 2, blocking intracellular insulin signaling. The latter is mediated by increased levels of both tumour necrosis factor-α (TNF-α) and suppressor of cytokine signaling 3 (SOC-3). IR, through different mechanisms, plays a role in the development of steatosis and its progression to steatohepatitis, cirrhosis and even HCC. In addition, IR has a role in impairing TNF signaling cascade, which in turn blocks STAT-1 translocation and interferon stimulated genes production avoiding the antiviral effect of interferon.
基金Supported by Grant-in-Aid for Research from the Third-Term Comprehensive Control Research for Cancer Center of the Ministry of Health, Labor and Welfare, JapanGrant from the Ministry of Education, Culture, Sports, Science and Technology, Japan(KIBAN-B)the "Collaborative Development of Innovative Seeds" Grant Program from the Japan Science and Technology Agency
文摘AIM: To determine the expression statuses of tumor necrosis factor (TNF)-α, its receptors (TNF-R) and downstream effector molecules in human colorectal adenomas. METHODS: We measured the serum concentrations of TNF-α and its receptors in 62 colorectal adenoma patients and 34 healthy controls. The protein expression of TNF-α, TNF-R1, TNF-R2 and downstream signals of the TNF receptors, such as c-Jun N-terminal kinase (JNK), nuclear factor-κ B and caspase-3, were also investigated in human colorectal adenomas and in normal colorectal mucosal tissues by immunohistochemistry. Immunofluorescence confocal microscopy was used to investigate the consistency of expression of TNF-R1 and phospho-JNK (p-JNK). RESULTS: The serum levels of soluble TNF-R1 (sTNF-R1) in adenoma patients were significantly higher than in the control group (3.67 ± 0.86 ng/mL vs 1.57 ± 0.72 ng/mL, P < 0.001). Receiver operating characteristic analysis revealed the high diagnostic sensitivity of TNF-R1 measurements (AUC was 0.928) for the diagnosis of adenoma, and the best cut-off level of TNF-R1 was 2.08 ng/mL, with a sensitivity of 93.4% and a specificity of 82.4%. There were no significant differences in the serum levels of TNF-α or sTNF-R2 between the two groups. Immunohistochemistry showed high levels of TNF-R1 and p-JNK expression in the epithelial cells of adenomas. Furthermore, a high incidence of co-localization of TNF-R1 and p-JNK was identified in adenoma tissue. CONCLUSION: TNF-R1 may be a promising biomarker of colorectal adenoma, and it may also play an important role in the very early stages of colorectal carcinogenesis.
基金the National Natural Science Foundation of China(No.81273836,Based on Ineegrin/FAK signaling pathways research the effects of electroacupuncture on the contents of apoptosisNo.81001554,Based on Wnt/β-catenin signaling pathways research the effects of electroacupuncture on the annulus fibrosis cells)
文摘OBJECTIVE: To examine whether electroacupuncture(EA) treatment inhibited cell apoptosis of intervertebral annulus fibrosis(AF) via tumor necrosis factor-α(TNF-α)-tumor necrosis factor receptor 1(TNFR1)-caspase-8 and integrin β1/Akt signaling pathways in a rat model of cervical intervertebral disc degeneration caused by unbalanced dynamic and static forces.METHODS: Thirty-two Sprague-Dawley rats were included in this study, of which 24 rats underwent surgery to induce cervical intervertebral disc degeneration, while eight rats received EA treatment at Dazhui(GV 14). Immunohistochemical staining was used to detect TNF-α, TNFR1, and caspase-8Apoptosis of AF cells was examined with terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling(TUNEL) staining. The m RNA and protein expression levels of integrin β1 andAkt were evaluated with real-time polymerase chain reaction and western blot analysis, respectively.RESULTS: Treatment with EA decreased TUNEL-positive AF cells and lowered TNF-α, TNFR1 and caspase-8 positive cells compared with control groups. EA treatment also increased integrin β1and Akt m RNA and protein levels compared with controls.CONCLUSION: Treatment with EA inhibits AF cell apoptosis through suppression of the TNF-α-TNFR1-caspase-8 signal pathway and increases the expression of integrin β1 and Akt. EA may be a good alternative therapy for treating cervical spondylosis.
基金supported by the National Natural Science Foundation of China (Grant No. 61141013)the Key Medical Talents of Jiangsu Province(Grant No. RC2011090)+1 种基金the Natural Science Foundation of Jiangsu Province (Grant No. SBK201120268)the 333 Program for High Level Talents of Jiangsu Province (Grant No. 2011III-2640)
文摘Liver transplantation is an established therapy for end-stage liver diseases. Graft rejection occurs unless the recipient receives immunosuppression after transplantation. This study aimed to explore the mechanism of acute rejection of liver allografts in rats pre-treated with total body irradiation to eliminate passenger lymphocytes and to define the role of CD4＋CD25＋ regulatory T cells in the induction of immunotolerance in the recipient. Male Lewis rats were used as donors and male DA rats were re- cipients. Rats were randomly assigned to the following four groups： control group, homogeneity liver transplantation group, idio-immunotolerance group and acute rejection group. After transplantation, the survival time of each group, serum alanine aminotransferase, total bilirubin levels, number of Foxp3＋CD4＋CD25＋ regulatory T cells, expression of glucocorticoid-induced tumor necrosis factor receptor on T cell subgroups, histopathology of the hepatic graft and spleen cytotoxic T lymphocyte lytic activity were measured. In the acute rejection group, where donors were preconditioned with total body in＇adiation before liver transplantation, all recipients died between day 17 and day 21. On day 14, serum alanine aminotransferase increased signifi- cantly to （459.2±76.9） U L^- 1, total bilirubin increased to （124.1±33.7） μmol L-1 （P〈0.05） and the ratio of Foxp3＋CD4＋CD25＋ regulatory T cells decreased significantly to 1.50%±0.50% （P〈0.05） compared with the other groups. Analysis of the T cell subpopulations in the acute rejection group varied from the other groups. Histological analysis showed typical changes of acute rejection in the acute rejection group only. Preconditioning of the donors with total body irradiation eliminated passenger lymphocytes of the liver graft, and thus affected the course of tolerance and induced acute rejection after liver transplantation.
基金supported by the Zhejiang University Special Fund for Fundamental Researchthe Fundamental Research Funds for the Central Universities(R14C070002)the Netherlands Organization of Scientific Research grant(MW-NWO 918.66.606),from the Cancer Genomics Centre Netherlands and the Centre for Biomedical Genetics
文摘The tumor-promoting arm of transforming growth factor beta(TGF-β)receptor signaling contributes to advanced cancer progression and is considered a master regulator of breast cancer metastasis.In mammals,there are six distinct members in the tumor-necrosis factor receptor(TNFR)-associated factor(TRAF)family(TRAF1–TRAF6),with the function of TRAF4 not being extensively studied in the past decade.Although numerous studies have suggested that there is elevated TRAF4 expression in human cancer,it is still unknown in which oncogenic pathway TRAF4 is mainly implicated.This review highlights TGF-β-induced SMAD-dependent signaling and non-SMAD signaling as the major pathways regulated by TRAF4 involved in breast cancer metastasis.
基金supported by Natural Science Foundation of China(Grant No.20972174)
文摘Sphingosine-1-phosphate（S1P） is a bioactive lipid messenger in the cells that regulate gene expression and NF-κB signal pathway through unknown mechanisms.Recently,Cheng Luo,associate professor of DDDC in Shanghai Institute of Materia Medica,whose project was funded by the National Natural Science Foundation of China,joined in a research team led by Professor Sarah Spiegel of Virginia Commonwealth University.The team continuously made significant breakthroughs in understanding the regulation mechanism of Sphingosine-1- Phosphate.In September 2009,in a paper published on SCIENCE magazine（Science 2009, 325：1254-7）,they firstly demonstrated that S1P is a physiologically important regulator of histone deacetylases（HDACs）,HDACs are direct intracellular targets of S1P.Furthermore,they identified the mechanism that S1P regulates gene expression through regulating the activity of HDACs.In June 24th,2010,in another paper to be published on NATURE magazine（Nature 2010,June 24th,advance online publication,（doi：10.1038/ nature09128）） which reports the regulation of NF-κB signaling pathway by S1P.They demonstrate that S1P is the missing cofactor for TRAF2（tumour-necrosis factor receptor-associated factor 2） and indicate a new paradigm for the regulation of lysine-63- linked poly-ubiquitination.The study also highlight the key role of SphK1 and its product S1P in TNF-αsignalling and the canonical NF-κB activation pathway, and then play crucial role in inflammatory,antiapoptotic and immune processes.The identification of new mechanisms fay which S1P regulates gene expression and TNF and NF-κB signaling pathway will light up the road to develop novel inhibitors that might be useful for treatment of cancer and in- flammatory diseases.
