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1.
The relationship between intracelluar trypsinogen activation and NF-κB activation in rat pancreatic acinar cells induced by M3 cholinergic receptor agonist (carbachol) hyperstimulation was studied. Rat pancreatic acinar cells were isolated, cultured and treated with carbachol, the active protease inhibitor (pefabloc) and NF-κB inhibitor (PDTC) in vitro. Intracelluar trypsin activity was measured by using a fluorogenic substrate. The activity of NF-κB was monitored by using electrophoretic mobility shift assay. The results showed that after pretreatment with 2 mmol/L pefabloc, the activities of trypsin and NF-κB in pancreatic acinar cells treated with high concertrations of carbachol (10^-3 mol/L) in vitro was significantly decreased as compared with control group (P〈0.01 ). The addition of 10^-2 mol/L PDTC resulted in a significant decrease of NF-κB activities in pancreatic acinar cells after treated with high concertrations of carbachol (10^-3 mol/L) in vitro, but the intracelluar trypsinogen activity was not obviously inhibited (P〉0.05). It was concluded that intracelluar trypsinogen activation is likely involved in the regulation of high concertrations of carbachol-induced NF-κB activation in pancreatic acinar cells in vitro. NF-κB activation is likely not necessary for high concertrations of carbachol-induced trypsinogen activation in pancreatic acinar cells in vitro.  相似文献   

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The relationship between M3 cholinergic receptor agonist (carbachol) hyperstimulationinduced pancreatic acinar cellular injury and trypsinogen activation or NF-κB activation in rats was studied in vitro. Rat pancreatic acinar ceils were isolated, cultured and treated with carbachol, the active protease inhibitor (pefabloc), and NF-κB inhibitor (PDTC) in vitro. Intracellular trypsin activity was measured by using a fluorogenic substrate. The cellular injury was evaluated by measuring the leakage of LDH from pancreatic acinar ceils. The results showed that as compared with control group, 10-3 mol/L carbachol induced a significant increase of the intracellular trypsin activity and the leakage of LDH from pancreatic acinar cells. Pretreatment with 2 mmol/L pefabloc could significantly decrease the activity of trypsin and the leakage of LDH from pancreatic acinar cells (P〈0. 01) following the treatment with a high concentration of carbachol (10^-3 mol/L) in vitro. The addition of 10^-2mol/L PDTC didn't result in a significant decrease in the activity of trypsin and the leakage of LDH from pancreatic acinar cells treated with a high concentration of carbachol (10^-3 mol/L) in vitro (P〉0. 05). It was concluded that intracellular trypsinogen activation is likely involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro. NF-κB activation may not be involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro.  相似文献   

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The relationship between intracelluar trypsinogen activation and NF-r,B activation in rat pancreatic acinar cells induced by M3 cholinergic receptor agonist (carbachoi) hyperstimulation was studied. Rat pancreatic acinar cells were isolated, cultured and treated with carbachol, the active pro- tease inhibitor (pefabloc) and NF-кB inhibitor (PDTC) in vitro. Intracelluar trypsin activity was measured by using a fluorogenie substrate. The activity of NF-кB was monitored by using electro- phoretic mobility shift assay. The results showed that after pretreatment with 2 mmol/L pefabloc, the activities of trypsin and NF-кB in pancreatic acinar cells treated with high concertrations of carbachol (10-3 mol/L) in vitro was significantly decreased as compared with control group (P<0.01). The addi- tion of 10-2mol/L PDTC resulted in a significant decrease of NF-кB activities in pancreatic acinar cells after treated with high concertrations of carbachol (10-3 mol/L) in vitro, but the intracelluar trypsinogen activity was not obviously inhibited (P>0.05). It was concluded that intracelluar trypsi- nogen activation is likely involved in the regulation of high concertrations of carbachol-induced NF-кB activation in pancreatic acinar cells in vitro. NF-кB activation is likely not necessary for high concertrations of carbachol-induced trypsinogen activation in pancreatic acinar cells in vitro.  相似文献   

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Background Surfactant protein A (SP-A) contributes to the regulation of sepsis-induced acute lung injury.In a previous study,we demonstrated the expression and localization of SP-A in the kidneys.The present study evaluated the effect of SP-A on lipopolysaccharide (LPS)-induced tumor necrosis factor-α (TNF-α) expression and its underlying mechanisms in the human renal tubular epithelial (HK-2) cells.Methods Indirect immunofiuorescence assay was used to detect SP-A distribution and expression in HK-2 cells.HK-2 cells were treated with various concentrations of LPS (0,0.1,1,2,5,and 10 mg/L) for 8 hours and with 5 mg/L LPS for different times (0,2,4,8,16,and 24 hours) to determine the effects of LPS on SP-A and TNF-α expression.Then,HK-2 cells were transfected with SP-A siRNA to analyze nuclear factor κB (NF-κB) P65 and TNF-α expression of HK-2 cells after LPS-treatment.Results Indirect immunofluorescence assay revealed that SP-A is localized to the membrane and cytoplasm of HK-2 cells.Interestingly,SP-A1/SP-A2 and TNF-α expression were found to be significantly increased in HK-2 cells upon LPS treatment.Transfection of LPS-treated HK-2 cells with SP-A siRNA resulted in significant increases in the levels of NF-κB P65 protein and TNF-α mRNA and protein compared to those in non-transfected LPS-treated HK-2 cells.Conclusion SP-A plays an important role in protecting cells against sepsis-induced acute kidney injury by inhibiting NF-κB activity to modulate LPS-induced increase in TNF-α expression.  相似文献   

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By study on the effect of anisodamine on lipopolysaccharide-induced expression of tissue factor(TF) in vascular endothelial cells (EC),the mechanism of anisodamine antithrombosis,as well as in the treatment of bacteraemic shock was investigated.Human umbilical vein endothelial cells (HUVECs) were cultured by trypsin digestion method.TF activity was measured in the lysates of HUVEC by using a single step clotting assay.Specific mRNA expression was detected by Northern blotting.In order to evaluate a possible contribution of the nuclear factor (NF)-κB pathway on the effects observed,electrophoretic mobility shift assays (EMSA) were performed using nuclear extracts from HUVECs and NF-κB-binding oligonucleotides.The results showed that treatment of HUVEC with LPS resulted in a significant increase in TF activity.Anisodamine dose-dependently inhibited LPS-induced upregulation of TF.These effects was also confirmed on the level of specific TF mRNA expression by Northern blotting.Furthermore,EMSA showed that anisodamine completely abolished LPS-induced NF-κB DNA binding activity in nuclear extracts from HUVECs treated with LPS together with anisodamine.The results suggest that anisodamine counteracts endothelial cell activation by inhibiting LPS-induced TF expression in these cells.Its interference with the NF-κB pathway might-at least in part-contribute to this effect.The ability of anisodamine to counteract LPS effect on endothelial cells might be one underlying mechanism explaining its antithrombosis and efficacy in the treatment of bacteraemic shock.  相似文献   

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Background It is accepted that inflammatory cytokines play a key role in the development of acute pancreatitis, so blocking the initiation of inflammatory reactions may alleviate pathological changes of acute pancreatitis. We studied the regulatory effect of arsenic trioxide (As2O3) on apoptosis and oncosis of pancreatic acinar cells in vitro and in vivo and its therapeutic effect on acute pancreatitis. Methods Pancreatic acinar cells were isolated by collagenase digestion method. Apoptosis and oncosis of isolated pancreatic acinar cells were detected with Hoechst 33258+PI or Annexin V+PI double fluorescent staining. Amylase and lactate dehydrogenase release were measured. Acute pancreatitis was induced in Wistar rats by intraperitoneal injections of caerulein, and apoptosis was detected with terminal dUTP nick-end labeling method. Tumor necorsis factor α (TNF-α) mRNA, myeloperoxidase, nuclear factor-κB and histological grading of pancreatic damage were measured. Results There was an increased apoptosis but a decreased oncosis of pancreatic acinar cell after the treatment with AS2O3. The levels of lactate dehydrogenase and amylase release were markedly decreased in As2O3 treated group. Myeloperoxidase content, TNF-α mRNA level, nuclear factor-κB activation and pathological score in As2O3 treated group were significantly lower than in the untreated group. Conclusions As2O3 can induce apoptosis and reduce oncosis of pancreatic acinar cell, thus resulting in reduced release of endocellular enzyme of acinar cells, reduced inflammatory cell infiltration and decreased the production of inflammatory cytokines, so that the outcome of alleviated pathological changes was finally achieved.  相似文献   

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The role of NF-κB in hepatocellular carcinoma cell   总被引:23,自引:0,他引:23  
Objective To evaluate the role of nuclear factor-kappaB (NF-κB) and IκBα in hepatocellular cacinoma (HCC) SMMC7721 cells, the consequence of NF-κB inhibition in SMMC7721 cells transfected with mutated IκBα (mIκBα) plasmid and the effect of stable inhibition of NF-κB activity in combination with Doxorubicin.Methods Western blot was used to determine the expression of NF-κB and IκBα in SMMC7721 cells and normal liver cells. Nuclear protein was used to evaluate the binding of the 32P-labeled tandem κB sequence using electrophoretic mobility shift assay and the expression of NF-κB using Western blot between SMMC7721 cells transfected with mIκBα plasmid (SMMC7721-MT) and control cells. Furthermore, cell viability was plotted between SMMC7721-MT and control cells. The binding of κB sequence and cell viability between SMMC7721-MT and control cells at different concentrations of Doxorubicin were also investigated.Results Western blot analysis for nuclear extract showed more P50 (NF-κB1) and P65 (RelA) expression in SMMC7721 cells compared with normal liver cells. The expression of cytosolic IκBα protein in SMMC7721 cells was less than that in normal cells. SMMC7721-MT cells inhibited NF-κB nuclear translocation at 0, 24, 48 and 96 hours. Furthermore, NF-κB cannot be detected in the nuclear protein of SMMC7721-MT cells by Western blot. By calculating cell viability, the proliferation of SMMC7721-MT cells was shown to be suppressed more significantly than that of control cells. NF-κB in untransfected cells was activated by Doxorubicin in a dose-dependent manner, but that in SMMC7721-MT cells was not induced at low concentrations of Doxorubicin. Compared with untransfected cells, the viability of SMMC7721-MT cells was significantly suppressed at the same concentration of Doxorubicin (P<0.01).Conclusions The present study demonstrates that upregulation of NF-κB and downregulation of inhibitory kappaB (IκBα) in SMMC7721 cells are related with the growth of hepatocellular cacinoma cells. Stable expression of mIκBα in SMMC7721-MT cells can inhibit NF-κB nuclear translocation and suppress cell growth. Furthermore, stable inhibition of NF-κB activity in combination with Doxorubicin can significantly inhibit cell proliferation in SMMC7721-MT cells. Thus, modulation of NF-κB may represent an improvement in the efficacy of HCC therapies and be worthy of further research and investigation.  相似文献   

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Objective: To explore the kinetics of the activation of nuclear factor-kappa B (NF-κB) and its regulation of interleukin-6 (IL-6) expression during LPS induced liver injury. Methods: Kunming mice were randomly divided into 4 groups in order to observe the does effect relationship at 3h: normal saline solution (control) group, low (1 mg/kg), middle (5 mg/kg), and high (10 mg/kg) LPS-induced groups; 6 groups in order to observe the time-effect relationship of 5 mg/kg LPS injection: normal saline solution (control) group, 0.5, 1, 3, 5 and 8 h groups ; pyrrolidine dithiocarbamate (PDTC) intervened groups (3 h): normal saline solution (control) group, 5 mg/kg LPS, 200 mg/kg PDTC, and 200 mg/kg PDTC+5 mg/kg LPS groups. NF-κB activities of Kupffer cells were determined with electrophoretic mobility shift assay (EMSA) and expression levels of IL-6 were measured with enzyme-linked immunosorbent assay (ELISA). Results: Does-effect of NF-κB activities in Kupffer cells after LPS injection 3 h: NF-κB activation could be detected in 1 mg/kg LPS group, reached the highest level in 5 mg/kg LPS group, and persisted in 10 mg/kg LPS group; time-course after 5 mg/kg LPS injection: the DNA-binding activity was observable at 0.5 h after LPS injection, increased significantly at 3 h, and persisted for at least 8 h; in addition, antioxidant PDTC could inhibit the activation of NF-κB significantly. The kinetics of IL-6 level in liver tissues during LPS-induced liver injury were that IL-6 level after 3 h of injection increased first and then reduced; the same trend was observed in the time-course on IL-6 level after LPS injection; PDTC could significantly inhibit the release of IL-6. Correlation analyses revealed that IL-6 level was significantly and positively correlated with the activation of NF-κB. Conclusion : NF-κB in Kupffer cells can be activitied during LPS-induced liver injury to some extent, and NF-κB may have some regulation on the expression of IL-6.  相似文献   

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Objective To elucidate the mechanisms by which Epstein- Barr virus- encoded latent membran e protein 1 activates NF- κB in nasopharyngeal carcinoma cells. Methods A tetracycline- regulated LMP1- expressing nasopharyngeal carcinoma cell line, T et- on- LMP1- HNE2, was used as the cell model. The kinetics of the expression of proteins, including LMP1, IκBα and IκBβ, was analyzed by Western blotting . The subcellular localization of NF- κB (p65) was detected by indirect immuno fluorescence assay. The NF- κB transactivity was studied by transient transfec tion and reporter gene assay. Results IκBα was phosphorylated and degraded after the inducible expression of LMP1, a lthough the total protein levels remained stable. The steady- state level of to tal IκBβ protein may have resulted from the initiation of an autoregulation lo op after the activation of NF- κB. No change in the IκBβ level was detected . NF- κB (p65) was translocated from the cytoplasm to the nucleus following de gradation of IκBα. After the introduction of the dominant- negative mutant of IκBα (Del 71) into Tet- on- LMP1- HNE2 cells, both nuclear translocation and transactivation of NF- κB induced by LMP1 was significantly inhibited. Conclusions The results indicated that in nasopharyngeal carcinoma cells, LMP1 activated NF - κB via phosphorylation and degradation of IκBα, but not IκBβ. The do minant- negative mutant of IκBα (Del 71) could completely inhibit both the nuc lear translocation and transactivation of NF- κB induced by LMP1.  相似文献   

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目的 探讨肿瘤坏死因子α( TNF-α) 中和抑制脂多糖( LPS) 诱导小鼠急性呼吸窘迫综合征( ARDS) 肺组织细胞凋亡的机制。方法 小鼠随机分为对照组、LPS 组和TNF-α中和组。采用LPS( 5 mg/kg) 气道雾化造小鼠ARDS 模型, TNF-α中和组在滴入LPS 前24 h 腹腔注射依那西普( 0. 4 mg/kg) , 滴入LPS 2 h 后收集标本。PCR 检测各组肺组织核转录因子κB( NF-κB) p65、Bax、Bcl-2的表达水平,Western blot 检测NF-κB p65 和Erk1 /2 及二者磷酸化、Bax、Bcl-2 的蛋白水平; 测量各组肺组织干湿重比; HE 染色观察各组肺组织病理改变, 采用肺损伤半定量评分评估肺组织损伤程度。结果 LPS 组肺组织NF-κB 及Erk1 /2 活化水平升高、Bcl-2 与Bax 比降低( P 〈0. 05) 。TNF-α中和能明显降低ARDS小鼠肺组织NF-κB 活化水平, Bcl-2 与Bax 比值升高。TNF-α中和组小鼠肺组织湿干重比及肺损伤半定量评分较LPS 组显著降低( P 〈0. 05) 。结论 TNF-α中和抑制脂多糖诱导小鼠ARDS肺组织损伤, 其机制与抑制Erk1/2、NF-κB 活化, 上调Bcl-2/Bax 比值, 最终减少细胞凋亡密切相关。  相似文献   

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免疫化学染色图像分析法检测细胞核因子κB   总被引:4,自引:0,他引:4  
目的 探讨一种简便、安全、可定量的细胞核因子κB(NF-KB)活性的检测方法。方法 以晚期糖基化终产物修饰的人血清白蛋白(HSA-AGE)刺激人脐静脉内皮细胞(HUVEC),NF-κB/p65免疫化学染色后,分析细胞NF-κB/p65核/浆的阳性染色比,以经典的凝胶迁徙率泳动分析法作对照。结果 HSA-AGE可激活HUVEC NF-κB,呈时间、剂量依赖关系,两种方法检测的趋势一致。结论 免疫化学染色的图像分析法可用于定量检测NF-κB的活性。  相似文献   

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目的 研究血管紧张素Ⅱ对ECV304细胞中转录因子NF-κB的作用和对PDGF-B 基因表达的影响.方法 采用电泳迁移率移动分析法(EMSA)和免疫组化方法,包括共聚焦显微镜及金颗粒标记免疫电镜技术;荧光素酶报告基因与变异型激酶质粒共转染的方法及Northern 印迹法研究血管紧张素Ⅱ激活NF-κB的信号传递路径和检测了血管紧张素Ⅱ刺激前后PDGF-B mRNA的表达水平.结果 血管紧张素Ⅱ刺激后,在ECV304细胞内有NF-κB的激活及核易位过程,应用免疫荧光共聚焦显微镜,免疫电镜及Northern 印迹等方法均可观察到PDGF-B或其基因表达增高.变异型激酶质粒IKKα-KM,IKKβ-KM 及 NIK-KM 可抑制经AngⅡ刺激的转染细胞内与NF-κB启动相连的荧光素酶的表达.结论 AngⅡ可激活胞浆内NF-κB并出现核易位,激酶NIK、IKKα和IKKβ参与了此信号传递路径.血管紧张素Ⅱ刺激后PDGF-B链mRNA水平增高.  相似文献   

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Multipledatahavesuggestedthattherenin angiotensinsystem (RAS )contributestothepathogenesisofatherosclerosis Acommonfeatureinallstagesofatherogenesisistheparticipationoftheinflammationprocessinthevesselwall 1 Thetranscriptionfactor,nuclearfactor kappaB (NF …  相似文献   

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目的探讨一种简便、安全、可定量的细胞核因子κB(NF-κB)活性的检测方法。方法以晚期糖基化终产物修饰的人血清白蛋白(HSA-AGE)刺激人脐静脉内皮细胞(HUVEC),NF-κB/p65免疫化学染色后,分析细胞NF-κB/p65核/浆的阳性染色比,以经典的凝胶迁徙率泳动分析法作对照。结果HSA-AGE可激活HUVECNF-κB,呈时间、剂量依赖关系,两种方法检测的趋势一致。结论免疫化学染色的图像分析法可用于定量检测NF-κB的活性。  相似文献   

17.
Pu Q  Yan L  Shen J 《中华医学杂志》1999,79(2):143-145
OBJECTIVE: To investigate the potential of pancreatic acinar cell calcium overload in the conversion of acute edematous pancreatitis (AEP) to necrotizing pancreatitis (ANP). METHODS: Ninety-six Sprague-Dawley rats were randomized in three experimental groups. Sham-operated control (Group I) AEP (Group II) was induced by pancreatic duct ligation and intravenous injection of bombesin (100 micrograms/kg) and secretin (10 micrograms/kg). ANP (Group III) was induced same as group II but with a large dose of dextran 110,000(500 mg/kg) intravenously. Pancreatic acinar cell Ca2+ overload was studied using fluorescent probe Fura2. Cytosolic free Ca2+ concentration ([Ca2+]i) in isolated pancreatic acinar cells and Ca(2+)-ATPase activity in pancreatic cell plasma membranes were determined 1, 3, 6, 9 h respectively after treatment. RESULTS: The results showed that pancreatic acinar cell [Ca2+]i was elevated at 1 h[(213 +/- 19) nmol/L, P < 0.05] and increased to (464 +/- 29) nmol/L at 6 h(P < 0.05) in rats with ANP, pancreatic cell plasma membrane Ca(2+)-ATPase activity decreased significantly from (29.8 +/- 0.4) nmol.min-1.mgp-1 at 1 h to (18.6 +/- 0.5) nmol.min-1.mgp-1 at 9 h in rats with ANP (P < 0.05). CONCLUSIONS: In ischemia-induced conversion of AEP to ANP, there exists Ca2+ overload in the pancreatic acinar cells. The decreased pancreatic cell plasma membrane Ca(2+)-ATPase activity may be an important reason for acinar cell Ca2+ overload in the development of acute pancreatitis.  相似文献   

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Background  Increased levels of plasma lipopolysaccharide (LPS) have been found in obesity and diabetes patients. This study was to investigate the effect of LPS on pancreatic beta-cell viability and the involvement of caspase 3 in NIT-1 cell line.
Methods  Mouse insulinoma NIT-1 cells were treated with LPS for the indicated time and dose. Cell viability was measured by cell counting kit-8 reagent. Toll-like receptor 4 (TLR4), caspase 3 and cleaved caspase 3 were detected by Western blotting. Insulin was determined by radioimmunoassay (RIA).
Results  LPS promoted NIT-1 cell proliferation at 1 µg/ml, peaked at 72 hours of incubation. A reduction in cleavage of caspase 3 was observed upon LPS treatment. Bay11-7082, a specific inhibitor of nuclear factor (NF)-κB, blunted LPS-induced inhibition of caspase 3 cleavage. Reduction in chronic insulin secretion was observed after treatment with LPS at 1 µg/ml for 48 and 72 hours, not for 24 hours. TLR4 protein was upregulated when NIT-1 cells were treated with LPS at 1 µg/ml for 24 hours.
Conclusions  LPS promotes early NIT-1 cell proliferation in association with NF-κB-mediated inhibition of caspase 3 cleavage. LPS exerts a time-dependent inhibitory effect on chronic insulin secretion from NIT-1 cells.
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目的探讨IL-10对小鼠巨噬细胞髓样分化因子88(MyD88)/核因子κB(NF-κB)炎症信号活化的影响。方法将小鼠巨噬细胞Ana-1分为脂多糖(LPS)组和LPS+IL-10组,分别于0.5、1及2h收集巨噬细胞和细胞培养上清液,Western blot检测细胞MyD88与胞浆、胞核NF-κBp65亚基表达,ELISA法检测培养上清中肿瘤坏死因子α(TNF-α)含量。结果在0~2h,LPS组细胞MyD88表达显著持续上升,LPS+IL-10组于LPS刺激后上升,0.5h达峰值,2h恢复至正常水平,1h和2h相对含量均低于LPS组(11.6±1.3比17.5±0.7,8.8±0.3比21.4±1.8,P0.05);总NF-κB表达量在两组间无明显差异。NF-κB核浆比变化趋势与MyD88类似,LPS+IL-10组1h及2h相对含量亦均低于LPS组(1.1±0.1比2.4±0.4,0.6±0.7比3.1±0.6,P0.05);相应的,LPS+IL-10组1h和2hTNF-α含量亦低于LPS组[(222.5±33.5)pg/mL比(365.2±22.7)pg/mL,(212.7±15.9)pg/mL比(566.2±31.5)pg/mL,P0.05]。结论 IL-10通过抑制减少MyD88/NF-κB信号通路活化,降低TNF-α表达,从而下调炎症反应强度。  相似文献   

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