The effects of tumor necrosis factor-α(TNF) on protein metabolism and cell-cycle kinetics were investigated in malignant tumor. Sprague-Dawley rats, subcutaneously inoculated with Walker 256 carcinosarcoma,were injec...The effects of tumor necrosis factor-α(TNF) on protein metabolism and cell-cycle kinetics were investigated in malignant tumor. Sprague-Dawley rats, subcutaneously inoculated with Walker 256 carcinosarcoma,were injected intraperitoneally with recombinant human TNF at a dose of 4-75×106 U/kg for 3 consecutive days.Tumor protein metabolism and cell-cycle kinetics were analyzed. The results showed a significant decrease in tumor volume and weight in comparison with control.TNF resulted in significant decrease in tumor Protein fractional synthesis rate, Protein synthesis and fractional growth rate, but no change of tumor protein fractional degradation rate. TNF also resulted in remarkable decline in labelling index and GI phase increase of tumor cells, 6 hours after bromodeoxyuridine injection, by cytometry. The results indicated that TNF inhibits tumor growth as a result of decreases in tumor cell DNA and protein syntheses.展开更多
Objective:To examine whether lipoxin A 4(LXA 4) has an inhibitory effect on tumor necrosis factor-α(TNF-α)-induced proliferation of glomerular mesangial cells of rat, and explore the molecular mechanisms of signal...Objective:To examine whether lipoxin A 4(LXA 4) has an inhibitory effect on tumor necrosis factor-α(TNF-α)-induced proliferation of glomerular mesangial cells of rat, and explore the molecular mechanisms of signal pathway in LXA 4 actions. Methods: Glomerular mesangial cells of rat were cultured and treated with TNF-α(10 ng/ml), with or without preincubation with LXA 4 at different concentrations. Cell proliferation was evaluated by monotetrazolium (MTT) colorimetric assay. The expression of cyclin E mRNA was measured by RT-PCR. Phosphorylated Akt1(Thr308) and p27 kip1 were analyzed by Western blotting. Results: TNF-α-stimulated proliferation of mesangial cells was inhibited by LXA 4 in a dose-dependent manner. The marked increments in cyclin E mRNA expression induced by TNF-α during proliferation of mesangial cells were down-regulated by LXA 4. Threonine phosphorylated Akt1 proteins at 308 site stimulated by TNF-α was reduced by LXA 4. TNF-α-induced decrements in expression of p27 kip1 proteins was ameliorated by LXA 4 in a dose-dependent manner. Conclusion: TNF-α-induced proliferation of rat mesangial cells can be inhibited by TXA 4 through the mechanism of Akt 1/p27 kip1 pathway-dependent signal transduction.展开更多
Tumor necrosis factor α （TNF-α） and interferon-γ （IFN-γ） are cytokines with strong antitumor activities. They were reacted with a photoactive arylazide-4-azidobenzoic acid, resulting in photoactive TNF-α and ...Tumor necrosis factor α （TNF-α） and interferon-γ （IFN-γ） are cytokines with strong antitumor activities. They were reacted with a photoactive arylazide-4-azidobenzoic acid, resulting in photoactive TNF-α and IFN-γ. The infrared （IR） spectra of these products showed the characteristic absorption of an azido group at 2127 cm^-1. By photo-immobilization, this modified TNF-α and IFN-γ were immobilized on polystyrene membranes for cell culture to prepare biomaterials. The micro-morphology of photoactive cytokines was observed with a scanning electron microscope （SEM）. The inhibitory effect on growth of Hela cells and inducing apoptosis activity of these two cytokines were analyzed by growth curve, transmission electron microscope （TEM） and fluorescence active cell sorter （FACS）. The results showed that co-immobilization of IFN-γ and TNF-α had significant inhibitory effect on growth of Hela cells, inhibitory rate up to 82%, and IFN-γ had obviously synergistic action.展开更多
Objective： To examine whether lipoxin A4 （LXA4） has an inhibitory effect on tumor necrosis factor-α（TNF-α-induced DNA synthesis of glomerular mesangial cells of rat, and explore the molecular mechanisms of LXA4 ...Objective： To examine whether lipoxin A4 （LXA4） has an inhibitory effect on tumor necrosis factor-α（TNF-α-induced DNA synthesis of glomerular mesangial cells of rat, and explore the molecular mechanisms of LXA4 action. Methods： Glomerular mesangial cells of rat were cultured and preincubated with LXA4 at different concentrations, and then treated with TNF-α（ 10 ng/ml）. DNA synthesis was assessed by the incorporation of [^3H]-thymidine in mesangial cells. Expression of cyclin E protein was determined by Western blotting analysis. Activities of signal transducers and activators of transcription-3 （STAT3） were analyzed by electrophoretic mobility shift assay （EMSA）. Results： TNF-α-stimulated DNA synthesis of mesangial cells, upregulafion of cyclin E protein and STAT3 activities were inhibited by LXA4 in a dose-dependent manner. Conclusion： TNF-α-induced DNA synthesis of mesangial cells can be inhibited by TXA4 probably through the mechanism of Jak1/STAT3 pathway-dependent signal transduction.展开更多
Objective To investigate the role of cyclin-kinase inhibitor p27 on proliferation of mesangial cell(MC) induced by tumor necrosis factor α( TNF-α ). Methods The p27 protein of MC lysate was detected with western blo...Objective To investigate the role of cyclin-kinase inhibitor p27 on proliferation of mesangial cell(MC) induced by tumor necrosis factor α( TNF-α ). Methods The p27 protein of MC lysate was detected with western blotting analysis. The degree of MC proliferation was estimated through [^3H] thymidine incorporation. The effect of reducing p27 expression on MC proliferation was analysed with p27 antisense oligodeoxynucleotide (ODN). Results TNF-α(200000U/L) decreased p27 level to (0.6±0.1 ) from (1. 1±0.1 ) of MC lysate cultured in serum free DMEM for 24h ( P<0.01 ) and increased [^3H] thymidine incorporation to ( 2060±112 ) from (685±53) cpm/well( P<0.01 ). p27 antisense ODN transfection decreased p27 level of MC stimulated by TNF-α for 24h [(0.3±0.1 ) vs (0.6±0.1), P <0.01 ] and increased [^3H] thymidine incorporation [(2420±130) vs (2060±112) cpm/well, P <0.05]. Conclusion The decline of p27 protein maybe play an important role in MC proliferation induced by TNF-α.展开更多
<Abstrat>The proliferation of mesangial cells on cyclosporin (CsA) test mediumwas studied by MTT assay and TNF-Q in cultured supernatant was examined byusing ELISA. The results showed that cyclosporin A signific...<Abstrat>The proliferation of mesangial cells on cyclosporin (CsA) test mediumwas studied by MTT assay and TNF-Q in cultured supernatant was examined byusing ELISA. The results showed that cyclosporin A significantly inhibited theproliferation of mesangial cells at the concentration between 0. 25 - 15 μg/ml(IC50 1μg/ml). This action appeared to be dose-dependent. Release of TNF-αfrom mesangial cells stimulated by LPS was also dose-dependently suppressed. Itis suggested that cyclosporin A play an important role in antiproliferation mecha-nism of mesangial cells in vitro.展开更多
Objective： Even though radiotherapy plays a major role in the local treatment of non-small cell lung cancer （NSCLC）, little is known about the molecular effects of irradiation in this tumor. In the present study, w...Objective： Even though radiotherapy plays a major role in the local treatment of non-small cell lung cancer （NSCLC）, little is known about the molecular effects of irradiation in this tumor. In the present study, we examined two NSCLC cell lines for their endogenous production of TNF-α after irradiation. To investigate the radiation-induced TNF-α production in NSCLC cell lines. Methods： Two human NSCLC cell lines （A549： squamous; NCI-H596： adenosquamous） were investigated for their TNF-α mRNA （real-time RT-PCR） after exposure to different irradiation doses （2, 5, 10, 20, 30, 40 Gy） and time intervals （1, 3, 6, 12, 24, 48 or 72 h）. The TNF-α mRNA expression was quantified by real-time RT-PCR. The clonogenic survival was evaluated after irradiation with 2, 4, 6 and 8 Gy. Results： Non-irradiated NSCLC cells exhibited no or very low TNF-α expression. For the NCI-H596 cell line, TNF-α expression was significantly elevated 1～12 h （maximum 6h： 568fold increase relative to unirradiated cells） in a time-dependent manner. The radiation-induced increase could be observed after irradiation with 2 Gy reaching maximal at 40 Gy, with 83 times higher than normal controls. The clonogenic survival of these cell lines was nearly identical. Conclusion： NCI-H596 cells produce significant quantities of TNF-α following irradiation in a time- and dose-dependent manner. The pro-inflammatory cytokine TNF-α is a key mediator for the pathogenesis of radiation pneumonitis. Radiation-induced endogenous TNF-α expression in NSCLC cells may affect the normal lung adjacent to the tumor and may be associated with an adverse clinical outcome of the patient.展开更多
目的观察过敏性紫癜性肾炎(HSPN)患儿刺激系膜细胞-足细胞轴及直接刺激足细胞对细胞增殖及肿瘤坏死因子(TNF)-α分泌的影响,从而探讨在HSPN发病机制中IgA1引起足细胞损伤的作用机制。方法采用层析法获得HSPN患儿及健康儿童血清单聚体IgA...目的观察过敏性紫癜性肾炎(HSPN)患儿刺激系膜细胞-足细胞轴及直接刺激足细胞对细胞增殖及肿瘤坏死因子(TNF)-α分泌的影响,从而探讨在HSPN发病机制中IgA1引起足细胞损伤的作用机制。方法采用层析法获得HSPN患儿及健康儿童血清单聚体IgA1(mIgA1),并热聚合为聚合IgA1(aIgA1),分别采用HSPN患儿aIgA1与系膜细胞共培养上清(aIgA1-MES上清组)、HSPN患儿的aIgA1(HSPN组)及健康儿童的aIgA1(健康儿童组)刺激足细胞,三组均采用50、100、250μg/mL三种浓度的aIgA1;并设不含aIgA1的阴性对照组。采用噻唑蓝(MTT)法检测刺激24 h及48 h足细胞的增殖情况;收集培养48 h的细胞培养基上清,用酶聚免疫吸附测定(ELISA)法测定TNF-α的水平。对比分析不同浓度的aIgA1对细胞增殖和TNF-α分泌水平的影响。结果 24 h MTT结果显示,aIgA1-MES上清组刺激足细胞在aIgA1浓度为100、250μg/mL的aIgA1中OD值明显低于阴性对照组(P<0.05),HSPN组及健康儿童组aIgA1直接刺激足细胞不能对细胞增殖产生影响(P>0.05);48 h MTT结果显示,IgA1-MES上清组在三种aIgA1浓度下足细胞OD值明显低于阴性对照组(P<0.05),HSPN组及健康儿童组直接刺激足细胞不能对细胞增殖产生影响(P>0.05);三种aIgA1浓度的aIgA1-MES上清组刺激足细胞分泌TNF-α含量较阴性对照组明显升高(P<0.01),三种aIgA1浓度的HSPN组及健康儿童组TNF-α含量与阴性对照组比较,差异无统计学意义(P>0.05)。结论 HSPN患儿aIgA1不能直接刺激足细胞造成细胞损伤,而是通过系膜细胞-足细胞轴抑制足细胞的增殖,并诱导足细胞分泌TNF-α水平增加。展开更多
文摘The effects of tumor necrosis factor-α(TNF) on protein metabolism and cell-cycle kinetics were investigated in malignant tumor. Sprague-Dawley rats, subcutaneously inoculated with Walker 256 carcinosarcoma,were injected intraperitoneally with recombinant human TNF at a dose of 4-75×106 U/kg for 3 consecutive days.Tumor protein metabolism and cell-cycle kinetics were analyzed. The results showed a significant decrease in tumor volume and weight in comparison with control.TNF resulted in significant decrease in tumor Protein fractional synthesis rate, Protein synthesis and fractional growth rate, but no change of tumor protein fractional degradation rate. TNF also resulted in remarkable decline in labelling index and GI phase increase of tumor cells, 6 hours after bromodeoxyuridine injection, by cytometry. The results indicated that TNF inhibits tumor growth as a result of decreases in tumor cell DNA and protein syntheses.
文摘Objective:To examine whether lipoxin A 4(LXA 4) has an inhibitory effect on tumor necrosis factor-α(TNF-α)-induced proliferation of glomerular mesangial cells of rat, and explore the molecular mechanisms of signal pathway in LXA 4 actions. Methods: Glomerular mesangial cells of rat were cultured and treated with TNF-α(10 ng/ml), with or without preincubation with LXA 4 at different concentrations. Cell proliferation was evaluated by monotetrazolium (MTT) colorimetric assay. The expression of cyclin E mRNA was measured by RT-PCR. Phosphorylated Akt1(Thr308) and p27 kip1 were analyzed by Western blotting. Results: TNF-α-stimulated proliferation of mesangial cells was inhibited by LXA 4 in a dose-dependent manner. The marked increments in cyclin E mRNA expression induced by TNF-α during proliferation of mesangial cells were down-regulated by LXA 4. Threonine phosphorylated Akt1 proteins at 308 site stimulated by TNF-α was reduced by LXA 4. TNF-α-induced decrements in expression of p27 kip1 proteins was ameliorated by LXA 4 in a dose-dependent manner. Conclusion: TNF-α-induced proliferation of rat mesangial cells can be inhibited by TXA 4 through the mechanism of Akt 1/p27 kip1 pathway-dependent signal transduction.
基金This work was supported by the China Postdoctoral Science Foundation under grant No.2004035588.
文摘Tumor necrosis factor α （TNF-α） and interferon-γ （IFN-γ） are cytokines with strong antitumor activities. They were reacted with a photoactive arylazide-4-azidobenzoic acid, resulting in photoactive TNF-α and IFN-γ. The infrared （IR） spectra of these products showed the characteristic absorption of an azido group at 2127 cm^-1. By photo-immobilization, this modified TNF-α and IFN-γ were immobilized on polystyrene membranes for cell culture to prepare biomaterials. The micro-morphology of photoactive cytokines was observed with a scanning electron microscope （SEM）. The inhibitory effect on growth of Hela cells and inducing apoptosis activity of these two cytokines were analyzed by growth curve, transmission electron microscope （TEM） and fluorescence active cell sorter （FACS）. The results showed that co-immobilization of IFN-γ and TNF-α had significant inhibitory effect on growth of Hela cells, inhibitory rate up to 82%, and IFN-γ had obviously synergistic action.
文摘Objective： To examine whether lipoxin A4 （LXA4） has an inhibitory effect on tumor necrosis factor-α（TNF-α-induced DNA synthesis of glomerular mesangial cells of rat, and explore the molecular mechanisms of LXA4 action. Methods： Glomerular mesangial cells of rat were cultured and preincubated with LXA4 at different concentrations, and then treated with TNF-α（ 10 ng/ml）. DNA synthesis was assessed by the incorporation of [^3H]-thymidine in mesangial cells. Expression of cyclin E protein was determined by Western blotting analysis. Activities of signal transducers and activators of transcription-3 （STAT3） were analyzed by electrophoretic mobility shift assay （EMSA）. Results： TNF-α-stimulated DNA synthesis of mesangial cells, upregulafion of cyclin E protein and STAT3 activities were inhibited by LXA4 in a dose-dependent manner. Conclusion： TNF-α-induced DNA synthesis of mesangial cells can be inhibited by TXA4 probably through the mechanism of Jak1/STAT3 pathway-dependent signal transduction.
文摘Objective To investigate the role of cyclin-kinase inhibitor p27 on proliferation of mesangial cell(MC) induced by tumor necrosis factor α( TNF-α ). Methods The p27 protein of MC lysate was detected with western blotting analysis. The degree of MC proliferation was estimated through [^3H] thymidine incorporation. The effect of reducing p27 expression on MC proliferation was analysed with p27 antisense oligodeoxynucleotide (ODN). Results TNF-α(200000U/L) decreased p27 level to (0.6±0.1 ) from (1. 1±0.1 ) of MC lysate cultured in serum free DMEM for 24h ( P<0.01 ) and increased [^3H] thymidine incorporation to ( 2060±112 ) from (685±53) cpm/well( P<0.01 ). p27 antisense ODN transfection decreased p27 level of MC stimulated by TNF-α for 24h [(0.3±0.1 ) vs (0.6±0.1), P <0.01 ] and increased [^3H] thymidine incorporation [(2420±130) vs (2060±112) cpm/well, P <0.05]. Conclusion The decline of p27 protein maybe play an important role in MC proliferation induced by TNF-α.
文摘<Abstrat>The proliferation of mesangial cells on cyclosporin (CsA) test mediumwas studied by MTT assay and TNF-Q in cultured supernatant was examined byusing ELISA. The results showed that cyclosporin A significantly inhibited theproliferation of mesangial cells at the concentration between 0. 25 - 15 μg/ml(IC50 1μg/ml). This action appeared to be dose-dependent. Release of TNF-αfrom mesangial cells stimulated by LPS was also dose-dependently suppressed. Itis suggested that cyclosporin A play an important role in antiproliferation mecha-nism of mesangial cells in vitro.
基金This work was supported by a grant fromChina Scholarship Council (No.20842007).
文摘Objective： Even though radiotherapy plays a major role in the local treatment of non-small cell lung cancer （NSCLC）, little is known about the molecular effects of irradiation in this tumor. In the present study, we examined two NSCLC cell lines for their endogenous production of TNF-α after irradiation. To investigate the radiation-induced TNF-α production in NSCLC cell lines. Methods： Two human NSCLC cell lines （A549： squamous; NCI-H596： adenosquamous） were investigated for their TNF-α mRNA （real-time RT-PCR） after exposure to different irradiation doses （2, 5, 10, 20, 30, 40 Gy） and time intervals （1, 3, 6, 12, 24, 48 or 72 h）. The TNF-α mRNA expression was quantified by real-time RT-PCR. The clonogenic survival was evaluated after irradiation with 2, 4, 6 and 8 Gy. Results： Non-irradiated NSCLC cells exhibited no or very low TNF-α expression. For the NCI-H596 cell line, TNF-α expression was significantly elevated 1～12 h （maximum 6h： 568fold increase relative to unirradiated cells） in a time-dependent manner. The radiation-induced increase could be observed after irradiation with 2 Gy reaching maximal at 40 Gy, with 83 times higher than normal controls. The clonogenic survival of these cell lines was nearly identical. Conclusion： NCI-H596 cells produce significant quantities of TNF-α following irradiation in a time- and dose-dependent manner. The pro-inflammatory cytokine TNF-α is a key mediator for the pathogenesis of radiation pneumonitis. Radiation-induced endogenous TNF-α expression in NSCLC cells may affect the normal lung adjacent to the tumor and may be associated with an adverse clinical outcome of the patient.
文摘目的观察过敏性紫癜性肾炎(HSPN)患儿刺激系膜细胞-足细胞轴及直接刺激足细胞对细胞增殖及肿瘤坏死因子(TNF)-α分泌的影响,从而探讨在HSPN发病机制中IgA1引起足细胞损伤的作用机制。方法采用层析法获得HSPN患儿及健康儿童血清单聚体IgA1(mIgA1),并热聚合为聚合IgA1(aIgA1),分别采用HSPN患儿aIgA1与系膜细胞共培养上清(aIgA1-MES上清组)、HSPN患儿的aIgA1(HSPN组)及健康儿童的aIgA1(健康儿童组)刺激足细胞,三组均采用50、100、250μg/mL三种浓度的aIgA1;并设不含aIgA1的阴性对照组。采用噻唑蓝(MTT)法检测刺激24 h及48 h足细胞的增殖情况;收集培养48 h的细胞培养基上清,用酶聚免疫吸附测定(ELISA)法测定TNF-α的水平。对比分析不同浓度的aIgA1对细胞增殖和TNF-α分泌水平的影响。结果 24 h MTT结果显示,aIgA1-MES上清组刺激足细胞在aIgA1浓度为100、250μg/mL的aIgA1中OD值明显低于阴性对照组(P<0.05),HSPN组及健康儿童组aIgA1直接刺激足细胞不能对细胞增殖产生影响(P>0.05);48 h MTT结果显示,IgA1-MES上清组在三种aIgA1浓度下足细胞OD值明显低于阴性对照组(P<0.05),HSPN组及健康儿童组直接刺激足细胞不能对细胞增殖产生影响(P>0.05);三种aIgA1浓度的aIgA1-MES上清组刺激足细胞分泌TNF-α含量较阴性对照组明显升高(P<0.01),三种aIgA1浓度的HSPN组及健康儿童组TNF-α含量与阴性对照组比较,差异无统计学意义(P>0.05)。结论 HSPN患儿aIgA1不能直接刺激足细胞造成细胞损伤,而是通过系膜细胞-足细胞轴抑制足细胞的增殖,并诱导足细胞分泌TNF-α水平增加。
