TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

TNF-α up-regulates protein tyrosine phosphatase 1B via NF-kB in HepG2 cells

HepG2 ceils were treated with various concentrations of tumor necrosis factor-or (TNF-α) for 24 hours. RT-PCR and Western blot were used to measure protein tyrosine phosphatase-1 B(PTP-1B)expression, and luciferase reporter assay was used to detect NF-kB activity. The results showed that treatment of HepG2 cells with TNF-α for 24 hours led to upregulation of PTP-1B and NF-kB activity in a dose-dependent manner. Inhibition of NF-kB by PI)TC significantly attenuated TNF-α-induced PTP-IB expression in HepG2 cells. Thus, the transactivation of NF-kB seems to play an important role in the expression of PTP-1B in HepG2 cells induced by TNF-α.     

肿瘤坏死因子α通过NF-kB上调HepG2细胞中蛋白酪氨酸磷酸酶1B的表达

用不同浓度的肿瘤坏死因子α(TNF-α)诱导人肝癌细胞(HepG2细胞),结果表明TNF-α上调HepG2细胞蛋白酪氨磷酸酶1B(PTP-1B)的表达,激活NF-kB,并呈浓度依赖性,抑制NF-kB能阻断TNF-α对HepG2细胞PTP-1B的上调作用.提示TNF-α可能通过激活NF-kB从而诱导HepG2细胞PTP-1B表达的上调.     

Tumor necrosis factor-α and diabetic nephropathy

Tumor necrosis factor-α(TNF-α)is an important inflammatory factor.In recent years,increasing evidences demonstrate that it participates in the pathogenesis of diabetic nephropathy.TNF-αinvolves in kidney injury by several mechanisms,such as damaging the glomerular permeability barrier,chansins glomerular hemodynamics,promoting mesangial cell proliferation,extracellular matrix accumulation,inflammation and inducing apeptosis.At present,there is a new strategy of therapy for diabetic nephropathy depending on restraining TNF-α.Such drugs including pentoxifylline and TNF-α specific antibody were studied.     

Helicobacter pylori tumor necrosis factor-α inducing protein promotes cytokine expression via nuclear factor-κB

AIM:To study the effects of Helicobacter pylori(H. pylori)tumor necrosis factor-α(TNF)inducing protein (Tip-α)on cytokine expression and its mechanism. METHODS:We cloned Tip-αfrom the H.pylori strain 26695,transformed Escherichia coli with an expression plasmid,and then confirmed the expression product by Western blotting.Using different concentrations of Tip-αthat affected SGC7901 and GES-1 cells at different times,we assessed cytokine levels using enzyme-linked immunosorbent assay.We blocked SGC7901 cells with pyrrolidine dithiocarbamate(PDTC),a specific inhibitor of nuclear factorκB(NF-κB).We then detected interleukin(IL)-1βand TNF-αlevels in SGC7901 cells. RESULTS:Western blot analysis using an anti-Tip-α antibody revealed a 23-kDa protein,which indicated that recombinant Tip-αprotein was recombined successfully.The levels of IL-1β,IL-8 and TNF-αwere sig-nificantly higher following Tip-αinterference,whether GES-1 cells or SGC-7901 cells were used(P<0.05).However,the levels of cytokines(including IL-1β,IL-8 and TNF-α)secreted by SGC-7901 cells were greater than those secreted by GES-1 cells following treatment with Tip-αat the same concentration and for the same duration(P<0.05).After blocking NF-κB with PDTC, the cells(GES-1 cells and SGC-7901 cells)underwent interference with Tip-α.We found that IL-1βand TNF-αlevels were significantly decreased compared to cells that only underwent Tip-αinterference(P<0.05). CONCLUSION:Tip-αplays an important role in cyto-kine expression through NF-κB.     

血清TNF-α IL-1β OPG与2型糖尿病合并冠心病的关系探讨

目的探讨肿瘤坏死因子α（ TNF-α）、白介素-1β（ IL-1β）、血清骨保护素（ OPG）与2型糖尿病合并冠心病的关系。方法入选健康个体（对照组）和2型糖尿病合并冠心病患者（冠心病组）各30例,用ELISA方法测定TNF-α、IL-1β、OPG,生化法测定血糖及糖化血红蛋白,并观察组间各指标的变化及相互关系。结果2型糖尿病合并冠心病组血清空腹血糖、糖化血红蛋白、OPG明显高于对照组（ P均＜0.01）, TNF-α、IL-1β高于对照组（ P均＜0.05）。 Spearman 相关分析显示, OPG与 TNF-α、IL-1β呈显著正相关（ P 均＜0.01）。结论血糖、糖化血红蛋白、TNF-α、IL-1β、OPG在2型糖尿病合并冠心病患者中明显增高,OPG与TNF-α、IL-1β改变有关。     

肿瘤坏死因子α和罗格列酮对30T3-L1细胞分化过程中蛋白酪氨酸磷酸酶1B表达的影响

目的 观察3T3-L1前脂肪细胞分化过程中蛋白酪氨酸磷酸酶1B（PTP1B）蛋白水平的变化以及肿瘤坏死因子α（TNF—α）和罗格列酮在前脂肪细胞分化过程中对PTP1B表达的影响，探讨PTP1B在脂肪细胞分化中的作用。方法 体外培养3T3-L1前脂肪细胞，分别采用3组诱导剂（完全诱导剂：3-异丁基-1-甲基黄嘌呤＋地塞米松＋胰岛素，C组），完全诱导剂加20μg/LTNF—α（CT组），完全诱导剂加10^-5mol／L罗格列酮（CR组）诱导脂肪细胞分化，以Western印迹方法检测各组脂肪细胞分化过程中PTP1B蛋白表达变化。结果 3组中PTP1B蛋白均表现为在前脂肪细胞中（第1天）表达最高，随着脂肪细胞分化成熟表达逐步降低，至第10天降至最低；与C组相比，CT组中脂肪细胞分化较为迟缓，其分化后期（第7～10天）PTP1B蛋白表达水平较C组显著增高；而CR组则表现为脂肪细胞分化活跃，其分化后期（第7～10天）PTP1B蛋白表达水平较C组显著降低。结论 在脂肪细胞分化成熟过程中PTP1B蛋白表达呈降低趋势：TNF—α及罗格列酮影响脂肪细胞胰岛素敏感性的作用可能与其调控PTP1B的表达有关。     

蛋白酪氨酸磷酸酶-1B与2型糖尿病

研究证实,蛋白酪氨酸磷酸酶-1B(PTP-1B)主要通过以下几方面参与2型糖尿病的发病(1)可与胰岛素受体及其底物相作用,减弱胰岛素信号转导,引起胰岛素抵抗。(2)参与对胰岛β细胞数量的调节。(3)与瘦素抵抗及脂代谢异常关系密切,由此引发并加重2型糖尿病。目前已合成各种类型的PTP-1B抑制剂,有良好的降糖等疗效,临床应用前景广阔。     

丙型肝炎病毒非结构蛋白5A抑制肿瘤坏死因子α诱导HepG2细胞凋亡的作用研究

目的 研究丙型肝炎病毒非结构蛋白5A(HCV NS5A)对肿瘤坏死因子α(TNFα)诱导HepG2细胞凋亡的抑制作用。方法 设计HCV—1b NS5A区基因片段的特异引物,以逆转录巢式PCR方法扩增NS5A基因片段,并将其进行TA克隆,对阳性克隆进行酶切与序列鉴定;构建NS5A基因表达载体;通过Lipofectamine基因转染法,将NS5A区基因导入HepG2细胞,加入TNFα培养48h;应用Western blot检测caspase-3被切割、细胞色素C释放的情况以及通过AnnecxinV-FITC染色两种方法,观察NS5A蛋白对TNFα诱导的HepG2细胞凋亡的抑制效应。结果 成功建立HCV NS5A蛋白真核表达转基因细胞模型,发现该蛋白对TNFα所诱导HepG2细胞凋亡有抑制作用。结论 HCV NS5A蛋白可以抑制TNFα诱导的HepG2细胞凋亡。     

蛋白酪氨酸磷酸酶-1B及其抑制剂与2型糖尿病

蛋白酪氨酸磷酸酶-1B(PTP-1B)是胰岛素信号转导的主要负调控因子,对2型糖尿病的发生、发展有重要作用。PTP-1B通过使胰岛素受体及其底物酪氨酸去磷酸化而阻断胰岛素的信号转导。2型糖尿病患者和动物模型PTP-1B的表达水平和活性均明显提高,引起胰岛素抵抗,而PTP-1B 基因敲除鼠胰岛素敏感性却升高。因此,深入研究PTP-1B及其有效的抑制剂对于2型糖尿病的治疗具有良好的发展前景。     

Bone-marrow mesenchymal stem cells reduce rat intestinal ischemia-reperfusion injury,ZO-1 downregulation and tight junction disruption via a TNF-α-regulated mechanism

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.     

蛋白酪氨酸磷酸酶-1B与肥胖和2型糖尿病

蛋白酪氨酸磷酸酶-1B(PTP-1B)是一种胰岛素信号的负性调节因子,与肥胖症和2型糖尿病的发病及发展关系密切。对PTP-1B基因敲除小鼠的研究表明,缺失PTP-1B小鼠的胰岛素敏感性明显增加,并对肥胖有一定的抵抗作用,而另一些对动物和人体的研究结果却与此相反,发现PTP-1B可通过引起胰岛素抵抗、瘦素抵抗及影响脂代谢等而导致肥胖症和2型糖尿病的发生。一些特异性的PTP-1B小分子抑制剂已经开发并用于肥胖和糖尿病的治疗中。     

Effect of tumor necrosis factor-α with different levels of iodine on expression of Na+/I- symporter in cultured lactating mammary cells

Objective To observe the expression of Na+/I- symporter(NIS) in cultured lactating mammary cells with different levels of iodine and the effect of tumor necrosis factor-α(TNF-α). Methods Original generation of mouse lactating mammary cells cultured in vitro were divided into low iodine group Ⅰ (LI-Ⅰ), low iodine group Ⅱ (LI-Ⅱ), adequate iodine group(AI), high iodine group Ⅰ(HI-Ⅰ), and high iodine group Ⅱ(HI-Ⅱ). Cells were cultured in DEME/F12 culture medium for 24 h with different concentrations of iodine (0,5,50,3000 and 10 000 μg/L, respectively), and TNF-α( 10-2 mg/L) was added to some of cultured cells for 24 h. The expression of NIS mRNA of lactating mammary cells was determined by real-time quantitative PCR and the expression of NIS protein was detected by In-Cell Western. Results In iodine alone group, the expression of NIS mRNA in LI-Ⅰ group [ (64.66 ± 14.99) x 10-4] was higher than that of AI group[ (22.76 ± 7.36) × 10-4, P ＜ 0.01 ]; HI-I group[ (10.18 ±3.53) × 10-4] and HI-Ⅱ group[ (8.59 ± 2.89) × 10-4] were lower than that of AI group(all P ＜ .0.05); With increased iodine concentration, the expression of NIS mRNA decreased. The expression of NIS mRNA in LI-Ⅰ group [(2.72 ± 0.45) × 10-4], LI-Ⅱ group[ (2.69 ± 0.68) × 10-4] and AI group[(1.80 ± 0.67) × 10-4] with iodine plus TNF-o were all lower than that of LI-Ⅰ group, LI-Ⅱ group[ (29.82 ± 4.47 ) × 10-4], and AI group without TNF-α (all P ＜ 0.01). In iodine plus TNF-α, the expression of NIS mRNA in HI-Ⅰ group[(6.58 ± 2.87) × 10-4] and HI-Ⅱ[(7.04 ± 1.36) × 10-4] group were all higher than that of AI group(all P ＜ 0.05); With increased iodine deficiency or iodine excess, the expression of NIS mRNA increased. With increased iodine concentration, the expression of NIS protein decreased in iodine alone group. The expression of NIS protein in iodine plus TNF-α was all lower than that in iodine alone group. In iodine plus TNF-α, the expression of NIS protein increased in both iodine deficiency and iodine excess conditions. Conclusions Iodine may decrease the expression of NIS mRNA and protein of lactating mammary cells. The expression of NIS mRNA and protein of lactating mammary cells was inhibited by TNF-α under different levels of iodine.