Effects of smoking cessation on expressions of nuclear factor-κB, matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in airway epithelial cells of smoking rats

Objective To investigate the effects of smoking and smoking cessation on airway inflammation and remodeling in chronic obstructive pulmonary diseases through detecting mRNA and protein expressions of nuclear factor-κB (NF-κB), cell matrix metalloproteinase-9 (MMP-9) and cellular tissue inhibitor of metalloproteinase-1 (TIMP-1) in airway epithelial cells of smoking and smoking cessation rats. Methods Twenty-four male Wistar rats were randomly divided into control group, smoking group and smoking cessation group,eight in each group. Hybridization in situ and immunohistochemistry were used to detect mRNA and protein expressions of NF-κB, MMP-9 and TIMP-1 in airway epithelial cells of rats. Results ① Compared with control group (0.29 ± 0.06,0.29±0.06), mRNA and protein expressions of NF-κB in smoking group (0.45±0.04,0.41±0.03) and smoking cessation group (0.40±0.05,0.37±0.03) were higher (all P＜0.05). The mRNA and protein expressions of NF-κB in smoking cessation group were lower than those in smoking group (all P ＜0.05). ②Compared with control group (0.30±0.06,0.30±0.06) ,mRNA and protein expressions of MMP-9 in smoking group (0.52±0.03,0.51±0.07) and smoking cessation group (0.38±0.03,0.33±0.02) were higher (all P＜0.05). The mRNA and protein expressions of MMP-9 in smoking cessation group were lower than those in smoking group (all P＜0.05). ③Compared with control group (0.26±0.04, 0.26±0.04), mRNA and protein expressions of TIMP-1 in smoking group (0.49±0.05,0.37±0.03) and smoking cessation group (0.42±0.04,0.35±0.03) were higher (all P ＜0.05). The mRNA and protein expressions of TIMP-1 in smoking cessation group were lower than those in smoking group (all P ＜ 0.05). ④ Compared with control group (1.00±0.02,1.00±0.02), MMP-9/TIMP-1 mRNA and protein expressions were larger than one in smoking group (1.07±0.14, 1.37±0.19), and less than one in smoking cessation group (0.92±0.13,0.94±0.10) (all P ＜0.05). ⑤The mRNA and protein expressions of NF-κB and MMP-9in each group were positively correlation (r=0.87,0.66,all P ＜0.05). Conclusions In airway epithelial cells of smoking rats, mRNA and protein expressions of NF-κB, MMP-9 and TIMP-1 increase, and MMP-9/TIMP-1 is larger than one. After stoping smoking, mRNA and protein expressions of NF-κB,MMP-9 and TIMP-1 decrease, and MMP-9/TIMP-1 is less than one. This experiment explains that smoking can cause airway inflammation and remodeling, smoking cessation can reduce airway inflammation and remodeling.     

Effects of smoking cessation on expressions of nuclear factor-κB, matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in airway epithelial cells of smoking rats

Objective To investigate the effects of smoking and smoking cessation on airway inflammation and remodeling in chronic obstructive pulmonary diseases through detecting mRNA and protein expressions of nuclear factor-κB (NF-κB), cell matrix metalloproteinase-9 (MMP-9) and cellular tissue inhibitor of metalloproteinase-1 (TIMP-1) in airway epithelial cells of smoking and smoking cessation rats. Methods Twenty-four male Wistar rats were randomly divided into control group, smoking group and smoking cessation group,eight in each group. Hybridization in situ and immunohistochemistry were used to detect mRNA and protein expressions of NF-κB, MMP-9 and TIMP-1 in airway epithelial cells of rats. Results ① Compared with control group (0.29 ± 0.06,0.29±0.06), mRNA and protein expressions of NF-κB in smoking group (0.45±0.04,0.41±0.03) and smoking cessation group (0.40±0.05,0.37±0.03) were higher (all P＜0.05). The mRNA and protein expressions of NF-κB in smoking cessation group were lower than those in smoking group (all P ＜0.05). ②Compared with control group (0.30±0.06,0.30±0.06) ,mRNA and protein expressions of MMP-9 in smoking group (0.52±0.03,0.51±0.07) and smoking cessation group (0.38±0.03,0.33±0.02) were higher (all P＜0.05). The mRNA and protein expressions of MMP-9 in smoking cessation group were lower than those in smoking group (all P＜0.05). ③Compared with control group (0.26±0.04, 0.26±0.04), mRNA and protein expressions of TIMP-1 in smoking group (0.49±0.05,0.37±0.03) and smoking cessation group (0.42±0.04,0.35±0.03) were higher (all P ＜0.05). The mRNA and protein expressions of TIMP-1 in smoking cessation group were lower than those in smoking group (all P ＜ 0.05). ④ Compared with control group (1.00±0.02,1.00±0.02), MMP-9/TIMP-1 mRNA and protein expressions were larger than one in smoking group (1.07±0.14, 1.37±0.19), and less than one in smoking cessation group (0.92±0.13,0.94±0.10) (all P ＜0.05). ⑤The mRNA and protein expressions of NF-κB and MMP-9in each group were positively correlation (r=0.87,0.66,all P ＜0.05). Conclusions In airway epithelial cells of smoking rats, mRNA and protein expressions of NF-κB, MMP-9 and TIMP-1 increase, and MMP-9/TIMP-1 is larger than one. After stoping smoking, mRNA and protein expressions of NF-κB,MMP-9 and TIMP-1 decrease, and MMP-9/TIMP-1 is less than one. This experiment explains that smoking can cause airway inflammation and remodeling, smoking cessation can reduce airway inflammation and remodeling.     

Melatonin inhibits IL1β-induced MMP9 expression and activity in human umbilical vein endothelial cells by suppressing NF-κB activation

Matrix metalloproteinases (MMPs) have been involved in inflammatory and degradative processes in pathologic conditions. The purpose of this study was to investigate the protective effect of melatonin in human umbilical vein endothelial cell (HUVEC) monolayer permeability and the regulation of MMP9 induced by interleukin 1β (IL1β (IL1B)) in HUVECs. Protection studies were carried out with melatonin, a well-known antioxidant and antiinflammatory molecule. MMP9 expression was increased with IL1β induction in HUVECs. Melatonin showed a barrier-protective role by downregulation of MMP9 and upregulation of tissue inhibitor of metalloproteinase-1 expression in HUVECs. Meanwhile, melatonin also decreased sodium fluorescein permeability and counteracted the downregulation of vascular endothelial cadherin and occludin expression in HUVECs. During inflammatory stimulus, nuclear factor-κB (NF-κB) plays a significant role in regulating MMP genes expression, thus the function of NF-κB in HUVECs' barrier disruption was investigated. IL1β induced nuclear translocation of NF-κB in HUVECs and regulated MMP9 expression. However, NF-κB translocation into the nucleus was inhibited significantly by melatonin. Our results show that melatonin decreases the permeability of monolayer endothelial cell induced by IL1β. At the same time, melatonin decreased the expression and activity of MMP9 by a NF-κB-dependent pathway in HUVECs induced by IL1β.     

The inhibition in tumor necrosis factor-α-induced attenuation in endothelial thrombomodulin expression by carvedilol is mediated by nuclear factor-κB and reactive oxygen species

Carvedilol, a nonselective β-adrenoceptor antagonist, has been shown to possess antioxidant effects and reduce the risk of hospitalization and death in patients with severe congestive heart failure, which is featured by the activation of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), and leads to thrombotic complications. Thrombomodulin (TM) plays protective roles against thrombosis. Treatment of ECs with TNF-α resulted in a down-regulation in the TM expression in a time-dependent manner. Pre-treatment of ECs with carvedilol (1 and 10 μM) for 1 h significantly up-regulated the TM expression in ECs in response to TNF-α. When ECs were pre-treated with a nuclear factor-κB (NF-κB) inhibitor, i.e., parthenolide, their TNF-α-mediated down-regulation of TM expression was inhibited. Pre-treatment of ECs with carvedilol inhibited the NF-κB-DNA binding activity in ECs induced by TNF-α. Our findings provide insights into the mechanisms by which carvedilol exerts anti-thrombotic effects by inducing TM expression in ECs in response to pro-inflammatory stimulation.     

Effects of tumor necrosis factor-α mono-clonal antibody on nuclear factor-κB activation and inducible nitric oxide synthase expression in rats with silicotic fibrosis

正Objective To investigate the effects of tumor necrosis factor-α(TNF-α)monoclonal antibody on nuclear factor-κB(NF-κB)activation and inducible nitric oxide synthase(iN OS)expression in rats with pulmonary fibrosis induced by silica dust.Methods A total of 48 male Wistar rats were randomly divided into intervention group,silica dust exposure group,and control group,with 16 rats in each group.The rats in the intervention     

Effect of NLRC5 on activation and reversion of hepatic stellate cells by regulating the nuclear factor-κB signaling pathway

BACKGROUND The formation of liver fibrosis is mainly caused by the activation of hepatic stellate cells(HSCs)and the imbalance of extracellular matrix(ECM)production and degradation.The treatment of liver fibrosis mainly includes removing the cause,inhibiting the activation of HSCs,and inhibiting inflammation.NOD-like receptor(NLR)family,caspase activation and recruitment domain(CARD)domain containing 5/NOD27/CLR16.1(NLRC5)is a highly conserved member of the NLR family and is involved in inflammation and immune responses by regulating various signaling pathways such as nuclear factor-κB(NF-κB)signaling.It has been found that NLRC5 plays an important role in liver fibrosis,but its specific effect and possible mechanism remain to be fully elucidated.AIM To investigate the role of NLRC5 in the activation and reversion of HSCs induced with transforming growth factor-β(TGF-β)and MDI,and to explore its relationship with liver fibrosis.METHODS A total of 24 male C57BL/6 mice were randomly divided into three groups,including normal,fibrosis,and recovery groups.Twenty-four hours after a liver fibrosis and spontaneous reversion model was established,the mice were sacrificed and pathological examination of liver tissue was performed to observe the degree of liver fibrosis in each group.LX-2 cells were cultured in vitro and treated with TGF-β1 and MDI.Real-time quantitative PCR(qPCR)and Western blot were used to analyze the expression levels of NLRC5,α-smooth muscle actin(α-SMA),and collagen type I alpha1(Col1a1)in each group.The activity of NF-κB in each group of cells transfected with NLRC5-siRNA was detected.RESULTS Compared with the normal mice,the expression level of NLRC5 increased significantly(P<0.01)in the fibrosis group,but decreased significantly in the recovery group(P<0.01).In in vitro experiments,the content of NLRC5 was enhanced after TGF-β1 stimulation and decreased to a lower level when treated with MDI(P<0.01).The expression ofα-SMA and Col1a1 proteins and mRNAs in TGF-β1-mediated cells was suppressed by transfection with NLRC5-siRNA(P<0.01).Western blot analysis showed that the expression of NF-κB p65 protein and phosphorylated IκBα(p-IκBα)was increased in the liver of mice in the fibrosis group but decreased in the recovery group(P<0.01),and the protein level of nuclear p65 and p-IκBαwas significantly increased after treatment with NLRC5-siRNA(P<0.01).CONCLUSION NLRC5 may play a key role in the development and reversal of hepatic fibrosis through the NF-κB signaling pathway,and it is expected to be one of the clinical therapeutic targets.     

Blockade of tumor necrosis factor-α-converting enzyme improves experimental small intestinal damage by decreasing matrix metalloproteinase-3 production in rats

Objective. Tumor necrosis factor (TNF)-α-converting enzyme (TACE), which has been purified, regulates maturity of TNF-α. Matrix metalloproteinases (MMPs) play a key role in various inflammatory conditions. The incidence of intestinal damage has increased, but the mechanism and treatment have not been well understood. The purpose of this study was to investigate the roles of TACE and MMP in indomethacin (Indo)-induced intestinal damage as well as the therapeutic effects of TACE inhibitor and selective MMP inhibitor (sMMPi) on this intestinal damage in rats.

Material and methods. In the first experiment, serial changes in intestinal ulcers and the production of MMP were investigated. In the second experiment, we assessed the effect of three TACE and/or MMP inhibitors and the production of TNF-α, TACE, MMP-3, -9 and tissue inhibitor of MMP (TIMP)-1. The rats were divided into five groups: a control group, and four groups that received Indo alone, Indo plus TACE inhibitor (GM6001), Indo plus a selective MMP-3 inhibitor and Indo plus an MMP-9/13 inhibitor, respectively.

Results. MMP-3 was overexpressed at 24?h after Indo administration, when intestinal injury was most prominent macroscopically and microscopically. GM6001 significantly decreased ulcer severity and suppressed MMP-3 in a dose-dependent fashion. The selective MMP-3 inhibitor dose-dependently ameliorated intestinal damage to the same degree as GM6001, but the MMP-9 inhibitor had no effect on the injury.

Conclusions. MMP-3 inhibition ameliorates intestinal damage without apparently affecting either TNF-α or TACE production and the dose–response curve suggests that the beneficial effect of the so-called TACE inhibitor is actually mainly mediated via MMP-3 inhibition rather than TNF-α inhibition.     

Augmented regeneration of partial liver allograft induced by nuclear factor-κB decoy oligodeoxynucleotides-modified dendritic cells

AIM:To investigate the effect of NF-κB decoy oligodeoxynuleotides (ODNs) - modified dendritic cells (DCs) on regeneration of partial liver allograft.METHODS:Bone marrow (BM)- derived DCs from SD rats were propagated in the presence of GM-CSF or GM-CSF+IL-4 to obtain immature DCs or mature DCs, respectively. GMCSF-propagated DCs were treated with double-strand NF-κB decoy ODNs containing two NF-κB binding sites or scrambled ODNs. Allogeneic (SD rat to LEW rat) 50% partial liver transplantation was performed. Normal saline (group A),GM-CSF-propagated DCs (group B), GM-CSF+IL-4-propagated DCs (group C), and GM-CSF+NF-κB decoy ODNs(group D) or scrambled ODNs -propagated DCs (group E) were injected intravenously into recipient LEW rats 7 days prior to liver transplantation and immediately after transplantation.DNA synthesis (BrdU labeling) and apoptosis of hepatocytes were detected with immunostaining and TUNEL staining postoperative 24h, 48h, 72h and 84h,respectively. Liver graft-resident NK cell activity, hepatic IFN-γ mRNA expression and recipient serum IFN-γ level at the time of the maximal liver allograft regeneration were measured with ^51Cr release assay, semiquantitative RT-PCR and ELISA, respectively.RESULTS: Regeneration of liver allograft was markedly promoted by NF-κB decoy ODNs-modified immature DCs but was significantly suppressed by mature DCs, the DNA synthesis of hepatocytes peaked at postoperative 72h in group A, group B and group E rats, whereas the DNA synthesis of hepatocytes peaked at postoperative 84h in group C rats and 48h in group D rats, respectively. The maximal BrdU labeling index of hepatocytes in group D rats was significantly higher than that in the other groups rats.NF-κB decoy ODNs-modified immature DCs markedly suppressed but mature DCs markedly promoted apoptosis of hepatocytes, liver-resident NK cell activity, hepatic IFN-γ mRNA expression and recipient serum IFN-γ production.At the time of the maximal regeneration of liver allograft,the minimal apoptosis of hepatocytes, the minimal activity of liver-resident NK cells, the minimal hepatic IFN-γ mRNA expression and serum IFN-y production were detected in group D rats. The apoptotic index of hepatocytes, the activityof liver- resident NK cells, the hepatic TFN-γ mRNA expression level and the serum IFN-γ level in group D rats were significantly lower than that in the other groups rats at the time of the maximal regeneration of liver allograft.CONCLUSION:The data suggest that the augmented regeneration of partial liver allograft induced by NF-κB decoy ODNs-modified Des may be attributable to the reduced apoptotic hepatocytes, the suppressed activity of liverresident NK cells and the reduced IFN-γ production.     

Enhanced expression of inflammatory cytokines and nuclear factor-κB in microglia by overdose fluoride

<正>Objective To investigate fluoride-induced inflammation and nuclear factor-κB(NF-κB)signaling pathway in cultured human acute monocytic leukemia cells(THP-1).Methods In vitro cultured THP-1 cells were used as a model of microglia.After cultured with different concentrations of[0(negative control group),10,50,100,     

Visfatin regulates the terminal processes of human labour and delivery via activation of the nuclear factor-κB pathway

The inflammatory process plays a pivotal role during the pathogenesis of human labour, both at term and preterm. Visfatin levels increase during normal human pregnancy and in infection associated preterm labour. The effects of visfatin in the processes of human labour and delivery, however, are not known. The aim of this study was to determine the effect of visfatin on the expression and release of pro-labour mediators in human placenta. Samples were obtained from normal pregnancies at the time of Caesarean section. Human placenta was incubated in the absence (basal control) or presence of a 50 ng/ml visfatin for 24 h (n = 6). Inflammatory gene expression was analysed by quantitative RT-PCR (qRT-PCR), the medium was collected and cytokine, prostaglandin and 8-isoprostane (marker of oxidative stress) release was quantified by ELISA, and secretory protease activity by zymography. Visfatin significantly increased IL-6 and IL-8 gene expression and secretion, COX-2 expression and resultant prostaglandin (PG) E₂ and PGF_2α release, and 8-isoprostane release. There was, however, no effect of visfatin on pro MMP-9 enzyme activity. These actions of visfatin were elicited via the nuclear factor-κB (NF-κB) pathway as visfatin induced the degradation of IκB-α (inhibitor of NF-κB) whilst increasing NF-κB p65 DNA binding activity. Further to this, visfatin-induced pro-labour responses were abrogated by treatment with the NF-κB inhibitor BAY 11-7082. Collectively, these data indicate that visfatin activates pro-inflammatory cytokine release and phospholipid metabolism in human placenta via activation of the NF-κB pathway. Thus, visfatin represents a novel cytokine linked to the events of human labour initiation.     

Expression of cytokine and chemokine mRNA and secretion of tumor necrosis factor-α by gallbladder epithelial cells: Response to bacterial lipopolysaccharides

Background

In addition to immune cells, many other cell types are known to produce cytokines. Cultured normal mouse gallbladder epithelial cells, used as a model system for gallbladder epithelium, were examined for their ability to express the mRNA of various cytokines and chemokines in response to bacterial lipopolysaccharide. The synthesis and secretion of the tumor necrosis factor-α (TNF-α) protein by these cells was also measured.

Results

Untreated mouse gallbladder cells expressed mRNA for TNF-α, RANTES, and macrophage inflammatory protein-2 (MIP-2). Upon treatment with lipopolysaccharide, these cells now produced mRNA for Interleukin-1β (IL-1β), IL-6, monocyte chemoattractant protein-1 (MCP-1), and showed increased expression of TNF-α and MIP-2 mRNA. Untreated mouse gallbladder cells did not synthesize TNF-α protein; however, they did synthesize and secrete TNF-α upon treatment with lipopolysaccharide.

Methods

Cells were treated with lipopolysaccharides from 3 strains of bacteria. Qualitative and semi-quantitative RT-PCR, using cytokine or chemokine-specific primers, was used to measure mRNA levels of TNFα, IL-1β, IL-6, IL-10, KC, RANTES, MCP-1, and MIP-2. TNF-α protein was measured by immunoassays.

Conclusion

This research demonstrates that gallbladder epithelial cells in response to lipopolysaccharide exposure can alter their cytokine and chemokine RNA expression pattern and can synthesize and secrete TNFα protein. This suggests a mechanism whereby gallbladder epithelial cells in vivo may mediate gallbladder secretory function, inflammation and diseases in an autocrine/paracrine fashion by producing and secreting cytokines and/or chemokines during sepsis.     

Effect of activation of nuclear factor-κB /hypoxia-inducible factor-1α pathway on the hippocampal neurodegeneration caused by status epilepticus in rats

<正>Objective To observe the roles of nuclear factor-κB(NF-κB)and hypoxia-inducible factor-1α(HIF-1α)in hippocampal neurodegeneration of status epilepticus(SE)rats,and explore whether HIF-1αactivation is regulated by NF-κB.Methods A total of 110 male Sprague-Dawley rats were randomly divided into seven groups:(1)Con-