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1.
Inhibition of mouse hepatocyte apoptosis via anti-Fas ribozyme   总被引:1,自引:0,他引:1  
AIM:To investigate the effects of anti-Fas ribozyme onFas expression and apoptosis in primary cultured mousehepatocytes.METHODS:Mouse hepatocytes were isolated by usingcollagenase irrigation.A hammerhead ribozyme targetingthe Fas mRNA was constructed,and transfected into mousehepatocytes via Effectene.Then Fas expression in mousehepatocytes was detected by RT-PCR and western blotting.After being treated with anti-Fas antibody(JO_2),hepatocytesviability was measured with MTT assay.Caspase-3 proteolyticactivity was detected,and cell apoptosis was measuredaccording to Annexin V-FITC apoptosis detection kit.RESULTS:Fas expressed in primary mouse hepatocytes.Fas expression in hepatocytes transfected with anti-Fasribozyme was decreased remarkably and correlated withthe resistance to Fas-mediated apoptosis as determinedby flow cytometry and caspase-3 proteolytic activity.CONCLUSION:Anti-Fas ribozyme can remarkably decreasethe Fas expression in mouse hepatocytes,thus inhibit Fas-mediated apoptosis in hepatocytes.It is suggested thatanti-Fas ribozyme could significantly increase the resistanceof transplanted hepatocytes to apoptosis and improve thesurvival of transplanted hepatocytes.  相似文献   

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AIM:To investigate the expression of toll-like receptor 4(TLR4)and MD-2 gene and protein in Kupffer cells(KCs)and their role in ischernia-reperfusion(IR)injury of ratliver graft.METHODS:KCs were isolated at 0(control group),2,12,24h(IR group)following IR in rat liver graft,mRNA expressionof TLR4 and MD-2 was detected by RT-PCR analysis,proteinexpression of TLR4/ND-2 was detected by flow cytometric(FCM)analysis,and tumor necrosis factor-α(TNF-α)levelin supernatant was measured by ELISA.Then isolated KCswere incubated with anti-TLR4 polyclonal antibody(anti-TLR4 group),and TNF-α level was measured again.RESULTS:The mRNA and protein expression of TLR4/MD-2 and the level of TNF-α in IR group increased significantlyat 2 h following IR,and reached the maximum at 12 h,andslightly decreased at 24 h,but were still significantly higherthan those in the control group(P<0.01).The expression ofthese factors was markedly decreased after anti-TLR4antibody treatment as compared with the IR group(P<0.01).CONCLUSION:Lipopolysaccharide(LPS)following IR canup-regulate TLR4/MD-2 gene and protein expression inKCs,and synthesize cytokine TNF-α.Anti TLR4 antibodycan inhibit the production of TNF-α induced by LPS.TLR4and its partner molecule MD-2 may play an important rolein Kupffer cell activation and IR injury.  相似文献   

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

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AIM: To explore the alterations of intestinal mucosa morphology, and the effects of tumor necrosis factor a (TNFα) on enterocyte apoptosis in mice with fulminant hepatic failure (FHF). METHODS: Liver damage was induced by lipopolysaccharide (LPS)/TNF-α in D-galactosamine (GaIN) sensitized BALB/c mice. There were 40 mice in normal saline (NS)-treated group, 40 mice in LPS-treated group, 40 mice in GaIN-treated group, 120 mice in GaIN/ LPS-treated group and 120 mice in GaIN/ TNFα-treated group. Each group was divided into five subgroups of eight mice each. Serum samples and liver, intestinal tissues were respectively obtained at 2, 6,9,12 and 24 h after administration. Anti-TNFa monoclonal antibody was injected intravenously into GaIN/LPS-treated mice. Serum TNFα levels were determined by enzyme linked immunosorbent assays (ELISA). Serum ALT levels were determined using an automatic analyzer. The intestinal tissues were studied under light microscope and electron microscope at 2, 6, 9,12 and 24 h in mice with fulminant hepatic failure, respectively. Enterocyte apoptosis was determined by terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) method. The expression of tumor necrosis factor receptor 1 (TNFR1) in intestinal tissue was tested by immunohistochemistry Envision Two Steps. RESULTS: Gut mucosa was morphologically normal at all time points in all groups, but typical apoptotic cells could be seen in all experimental groups under electron microscope. Apoptosis rate of gut mucosal epithelial cells were significantly increased at 6, 9 and 12 h, peaked at 12 h in mice with fulminant hepatic failure. TNFa induced apoptosis of enterocytes in mice with FHF. The integrated OD (IOD) levels of TNFa receptor 1 protein expressed in the intestine of mice with GaIN/LPS and GaIN/ TNFα induced FHF at 2, 6, 9, 12 and 24 h after GaIN/LPS and GaIN/TNFα administration were 169.54±52.62/905.79±111.84,11 350.67±2 133.26/28 160.37±4 601.67, 25 781.00±2 277.75/122 352.30±49 412.40, 5 241.53±3 007.24/ 49 157.93±9 804.88, 7 086.13±1 031.15/3 283.45±127.67, respectively, compared with those in control groups (with NS, LPS and GaIN administration, respectively). IOD level of TNFR1 changed significantly at 6, 9 and 12 h after GaIN/LPS and GalN/TNFa administration. The expression of TNFR1 protein was significantly higher at 9 h after GaIN/LPS and GaIN/TNFα administration than that in control groups. Protein expression of TNFR1 was positively correlated with enterocyte apoptosis. CONCLUSION: TNFα can induce apoptosis of enterocytes in mice with FHF. Anti-TNFα IgG can inhibit this role.  相似文献   

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AIM To evaluate the effect of oxymatrine(OMT) on hepatocyte apoptosis in rats with lipopolysaccharide(LPS)/D-galactosamine(D-Gal N)-induced acute liver failure(ALF). METHODS LPS/D-Gal N was used to establish a model of ALF in rats. To evaluate the effect of OMT, we assessed apoptosis by transmission electron microscopy, and the pathological changes in the liver by light microscopy with hematoxylin and eosin staining. An automated biochemical analyzer was used to measure serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST). Enzyme-linked immunosorbent assay was used to determine the levels of tumor necrosis factor(TNF)-α and interleukin(IL)-1β. Western blotting was used to detect protein levels in liver tissues. Streptavidin peroxidase immunohistochemistry was used to observe expression of Toll-like receptor(TLR)4, active caspase-3, Bax and Bcl-2. RESULTS All rats in the normal control and OMT-pretreated groups survived. The mortality rate in the model group was 30%. OMT preconditioning down-regulated apoptosis of hepatocytes and ameliorated pathological changes in liver tissue. The levels of AST, ALT, TNF-α and IL-1β in the model group increased significantly, and were significantly reduced by OMT pretreatment. OMT pretreatment down-regulated expression of TLR4 and active caspase-3 and the Bax/Bcl-2 ratio, and upregulated expression of P-AktSer473(Akt phosphorylated at serine 473) and P-GSK3βSer9(glycogen synthase kinase 3β phosphorylated at serine 9) induced by LPS/D-Gal N. CONCLUSION OMT inhibits hepatocyte apoptosis by suppressing the TLR4/PI3K/Akt/GSK-3β signaling pathway, which suggests that OMT is an effective candidate for ameliorating acute liver failure.  相似文献   

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Aim: Lipopolysaccharide (LPS) causes apoptosis of hepatocytes, which is probably mediated by inflammatory substances released from Kupffer cells (KCs). Recently, we have reported that naofen, a newly found intracellular WD40-repeat protein, has a role in inducing the apoptosis in HEK293 cells. Hence, the present study was undertaken to investigate a role of naofen in the LPS-induced apoptosis of rat hepatocytes. Methods: Rats were treated with i.v. injections of LPS, and livers were extirpated to evaluate expression of naofen and apoptosis. In in vitro experiments, hepatocytes and KCs were separately isolated from rat livers. The incubation medium for KCs treated with LPS (KC-CM) was used for hepatocyte culture. Results: Intravenous injections of LPS enhanced the expression of naofen in the livers. Livers showed terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive staining, and elevated caspase-3 activity. In isolated KCs or hepatocytes, LPS hardly affected naofen expression and caspase-3 activity, whereas incubation of hepatocytes with KC-CM enhanced both naofen expression and caspase-3 activation. Transfection of hepatocyte with naofen siRNA prevented such effects of KC-CM, and clearly eliminated KC-CM-induced reduction of Bcl-2 and Bcl-xL. In contrast, overexpression of naofen in hepatocytes downregulated Bcl-2 and Bcl-xL, released cytochrome c from mitochondria, and activated caspase-3. Conclusion: These results indicate that LPS may induce the hepatic apoptosis in association with enhanced naofen expression, and that naofen may mediate the activation of caspase-3 through downregulating the Bcl-2 and Bcl-xL expression, and releasing cytochrome c from mitochondria to cytoplasm.  相似文献   

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AIM: To investigate the role of octreotide on cellular proliferation and apoptosis of human hepatoma (HepG2) cells. METHODS: We studied cellular proliferation, apoptosis and the possible internal caspase-mediated apoptosis pathway involved, after treatment of HepG2 carcinoma cells with octreotide in comparison with the apoptosis caused by tumor necrosis factor-α (TNF-α). Activities of caspase-3, caspase-9, caspase-8 and caspase-2 were studied, while apoptosis was investigated through detection of DNA fragme...  相似文献   

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AIM: To investigate the role of hepatic peroxisome proliferator-activated receptor-γ (PPAR-γ) in increased susceptibility to endotoxin-induced toxicity in rats with bile duct ligation during endotoxemia.METHODS: Male Sprague-Dawley rats were subjected to bile duct ligation (BDL). Sham-operated animals served as controls. DNA binding were determined by polymerase chain reaction, Western blotting analysis,and electrophoretic mobility shift assay, respectively.BDL and sham-operated rats received a non-lethal d...  相似文献   

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AIM: To investigate the effect of bone-marrow mesenchymal stem cells (BM MSCs) on the intestinal mucosa barrier in ischemia/reperfusion (I/R) injury. METHODS: BM MSCs were isolated from male Sprague-Dawley rats by density gradient centrifugation, cultured, and analyzed by flow cytometry. I/R injury was induced by occlusion of the superior mesenteric artery for 30 min. Rats were treated with saline, BM MSCs (via intramucosal injection) or tumor necrosis factor (TNF)-α blocking antibodies (via the tail vein). I/R injury was assessed using transmission electron microscopy, hematoxylin and eosin (HE) staining, immunohistochemistry, western blotting and enzyme linked immunosorbent assay.RESULTS: Intestinal permeability increased, tight junctions (TJs) were disrupted, and zona occludens 1 (ZO-1) was downregulated after I/R injury. BM MSCs reduced intestinal mucosal barrier destruction, ZO-1 downregulation, and TJ disruption. The morphological abnormalities after intestinal I/R injury positively correlated with serum TNF-α levels. Administration of anti-TNF-α IgG or anti-TNF-α receptor 1 antibodies attenuated the intestinal ultrastructural changes, ZO-1 downregulation, and TJ disruption. CONCLUSION: Altered serum TNF-α levels play an important role in the ability of BM MSCs to protect against intestinal I/R injury.  相似文献   

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AIM:To investigate the correlation between the appearance of skin lesions and concentration of interleukin(IL)-17A,IL-23 and interferon-γ(IFN-γ)in Crohn’s disease(CD)patients during anti-tumor necrosis factor-α(TNF-α)therapy METHODS:A prospective study included 30 adult patients with CD of Caucasian origin(19 men and 11women;mean age±SD 32.0±8.6 years)during biological therapy with anti-TNF-αantibodies from January2012 to March 2013.Eighteen patients were treated with infliximab,seven with adalimumab and five withcertolizumab.Inclusion criteria were exacerbation of the underlying disease,Crohn’s Disease Activity Index over 300 and the ineffectiveness of previously used non-biological therapies.Patients with a history of psoriasis,atopic dermatitis and other autoimmune skin lesions were excluded from the study.The control group consisted of 12 healthy subjects.A diagnostic survey was carried out,blood tests and careful skin examination were performed,and the serum levels of IL-17,IL-23 and IFN-γwere measured using an enzyme-linked immunosorbent assays technique.Dermatoses that have developed in the course of biological therapy in patients who had no pre-existing skin lesions of similar character were qualified as skin lesions induced by antiTNF-αtherapy.RESULTS:Skin manifestations occurred in 18 of CD patients during the anti-TNF-αtherapy(60%),in the average time of 10.16±3.42 mo following the beginning of the 52-wk treatment cycle.Skin lesions observed in CD patients during biological therapy included psoriasiform lesions(44.4%),and eczema forms lesions(22.2%).In CD patients with drug induced skin lesions significantly higher levels of hemoglobin(13.3±1.5 g/dL vs 10.8±1.9 g/dL,P=0.018)and hematocrit(39.9%±4.5%vs 34.3%±5.4%,P=0.01),as well as a significantly lower level of platelets(268±62×103/μL vs 408±239×103/μL,P=0.046)was observed compared with CD patients without skin manifestations.The concentrations of IL-17A and IL-23in CD patients with skin lesions developed under antiTNF-αtherapy were significantly higher compared to those in patients without lesions(IL-17A:39.01±7.03pg/mL vs 25.71±4.90 pg/mL,P=0.00004;IL-23:408.78±94.13 pg/mL vs 312.15±76.24 pg/mL,P=0.00556).CONCLUSION:Skin lesions in CD patients during bio-logical therapy may result from significantly increased concentrations of IL-17A and IL-23,which are strongly associated with TNF-α/Th1 immune pathways.  相似文献   

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AIM: To assess the effects of dihydromyricetin(DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride(CCl4) treatment.METHODS: C57 BL/6 mice were used in this study. Mice were orally administered with DHM(150 mg/kg) for 4 d after CCl4 treatment. Serum and liver tissue samples were collected on days 1, 2, 3, 5 and 7 after CCl4 treatment. The anti-inflammatory effect of DHM was assessed directly by hepatic histology detection and indirectly by serum levels of aspartate aminotransferase(AST), alanine aminotransferase(ALT), albumin, and superoxide dismutase(SOD). Inflammatory cytokines, such as interleukin(IL)-1β, IL-6 and tumor necrosis factor-α(TNF-α), were detected using ELISA kits. Proliferating cell nuclear antigen(PCNA) staining was used to evaluate the role of DHM in promoting hepatocyte proliferation. Hepatocyte apoptosis wasmeasured by TUNEL assay.Furthermore,apoptosis proteins Caspases-3,6,8,and 9 were detected by Western blot.SP600125 were used to confirm whether DHM regulated liver regeneration through JNK/TNF-αpathways.RESULTS:DHM showed a strong anti-inflammatory effect on CCl4-induced liver injury in mice.DHM could significantly decrease serum ALT,AST,IL-1β,IL-6 and TNF-αand increase serum albumin,SOD and liver SOD compared to the control group after CCl4 treatment(P0.05).PCNA results indicated that DHM could significantly increase the number of PCNA positive cells compared to the control(348.9±56.0 vs 107.1±31.4,P0.01).TUNEL assay showed that DHM dramatically reduced the number of apoptotic cells after CCl4 treatment compared to the control(365.4±99.4 vs 90.5±13.8,P0.01).Caspase activity detection showed that DHM could reduce the activities of Caspases-8,3,6 and 9 compared to the control(P0.05).The results of Western blot showed that DHM increased the expression of JNK and decreased TNF-αexpression.However,DHM could not affect TNF-αexpression after SP600125 treatment.Furthermore,DHM could significantly improve the survival rate of acute liver failure(ALF)mice(73.3%vs 20.0%,P0.0001),and SP600125 could inhibit the effect of DHM.CONCLUSION:These findings demonstrate that DHM alleviates CCl4-induced liver injury,suggesting that DHM is a promising candidate for reversing liver injury and ALF.  相似文献   

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内毒素诱导原代肝细胞表达FasL及其细胞毒效应   总被引:4,自引:1,他引:3  
目的 探讨内毒素直接与间接致肝细胞凋亡在内毒素血症肝脏损伤中的病理机制。方法 采用低浓度胶原酶原位循环灌流法分离,培养肝细胞,经不同浓度内毒素(1、5、10μg/ml)作用24、48h后免疫组织化学法检测肝细胞膜性FasL(mFasL)表达及TUNEL试验检测内毒素直接与间接致肝细胞凋亡情况。结果 内毒素作用24h后肝细胞mFasL表达阳性程度为++-+++,对照组为阴性,内毒素直接作用24h后肝  相似文献   

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AIM:To determine the effect of tumor necrosis factor alpha(TNF-α) on intestinal permeability(IP) in mice with fulminant hepatic failure(FHF),and the expression of tight junction proteins.METHODS:We selected D-lactate as an index of IP,induced FHF using D-galactosamine/lipopolysaccharide and D-galactosamine/TNF-α,assessed the results using an enzymatic-spectrophotometric method,transmission electron microscopy,immunohistochemistry,Western blotting and real-time quantitative polymerase chain reaction.The effect of the administration of antiTNF-α immunoglobulin G(IgG) antibody,before the administration of D-galactosamine/lipopolysaccharide,on TNF-α was also assessed.RESULTS:IP was significantly increased in the mouse model of FHF 6 h after injection(13.57 ± 1.70 mg/L,13.02 ± 1.97 mg/L vs 3.76 ± 0.67 mg/L,P = 0.001).Electron microscopic analysis revealed tight junction(TJ) disruptions,epithelial cell swelling,and atrophy of intestinal villi.Expression of occludin and claudin-1 mRNA was significantly decreased in both FHF models(occludin:0.57 ± 0.159 fold vs baseline,P = 0.000;claudin-1:0.3067 ± 0.1291 fold vs baseline,P = 0.003),as were the distribution density of proteins in the intestinal mucosa and the levels of occludin and claudin-1 protein(occludin:0.61 ± 0.0473 fold vs baseline,P = 0.000;claudin-1:0.6633 ± 0.0328 fold vs baseline,P = 0.000).Prophylactic treatment with antiTNF-α IgG antibody prevented changes in IP(4.50 ± 0.97 mg/L vs 3.76 ± 0.67 mg/L,P = 0.791),intestinal tissue ultrastructure,and the mRNA levels of occludin and claudin-1 expression(occludin:0.8865 ± 0.0274 fold vs baseline,P = 0.505;claudin-1:0.85 ± 0.1437 fold vs baseline,P = 0.1),and in the protein levels(occludin:0.9467 ± 0.0285 fold vs baseline,P 0.05;claudin-1:0.9533 ± 0.0186 fold vs baseline,P = 0.148).CONCLUSION:Increased in IP stemmed from the downregulation of the TJ proteins occludin and claudin-1,and destruction of the TJ in the colon,which were induced by TNF-α in FHF mice.  相似文献   

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Background and AimsThe effect of ginsenoside Rb1 on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced acute liver injury (ALI) is unknown. The aim of this study was to evaluate the effect of ginsenoside Rb1 on ALI and its underlying mechanisms.MethodsMice were pretreated with ginsenoside Rb1 by intraperitoneal injection for 3 days before D-GalN/LPS treatment, to induce ALI. The survival rate was monitored every hour for 24 h, and serum biochemical parameters, hepatic index and histopathological analysis were evaluated to measure the degree of liver injury. ELISA was used to detect oxidative stress and inflammatory cytokines in hepatic tissue and serum. Immunohistochemistry staining, RT-PCR and western blotting were performed to evaluate the expression of toll-like receptor 4 (TLR4), nuclear factor-kappa B (NF-κB), and NLR family, pyrin domain-containing 3 protein (NLRP3) in liver tissue and Kupffer cells (KCs).ResultsGinsenoside Rb1 improved survival with D-GalN/LPS-induced ALI by up to 80%, significantly ameliorated the increased alanine and aspartate transaminase, restored the hepatic pathological changes and reduced the levels of oxidative stress and inflammatory cytokines altered by D-GalN/LPS. Compared to the control group, the KCs were increased in the D-GalN/LPS groups but did not increase significantly with Rb1 pretreatment. D-GalN/LPS could upregulate while Rb1 pretreatment could downregulate the expression of interleukin (IL)-1β, IL-18, NLRP3, apoptosis associated speck-like protein containing CARD (ASC) and caspase-1 in isolated KCs. Furthermore, ginsenoside Rb1 inhibited activation of the TLR4/NF-κB signaling pathway and NLRP3 inflammasome induced by D-GalN/LPS administration.ConclusionsGinsenoside Rb1 protects mice against D-GalN/LPS-induced ALI by attenuating oxidative stress and the inflammatory response through the TLR4/NF-κB signaling pathway and NLRP3 inflammasome activation.  相似文献   

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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.  相似文献   

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