Activation of Akt signal pathway cascades in kidney tissue in murine chronic graft-versus-host disease lupus nephritis and its regulation by prednisone

AIM:To examine whether Akt signal pathway proteins, including Akt, NF-κB and IκBα, are activated in kidney tissue of murine chronic graft-versus-host disease (GvHD) lupus nephritis in vivo, and whether prednisone suppresses activation of them.METHODS:Akt activity and phosphorylated IκBα were detected by Western-blot. Activation of NF-κB was detected by electropheretic mobility shift assay (EMSA). RESULTS:Activity of Akt, NF-κB and phosphorylated IκBα were significantly increased in kidney tissue of murine chronic graft-versus-host disease (GvHD) in 8th week and 12th week after monocell injection, respectively. However, they were no significant elevation in 16th week, when compared with controls. Prednisone treatment significantly prevented the increase in serum anti-dsDNA antibody level, urinary protein excretion and glomerular cell proliferation in GvHD mice, indicating the beneficial effects of prednisone on this model. Prednisone also significantly suppressed the increase in the activities of glomerular Akt, NF-κB and phosphorylated IκBα. CONCLUSION:This study provides the first evidence of marked increase in glomerular Akt-NF-κB signal pathway activities in murine chronic graft-versus-host disease lupus nephritis. The beneficial effect of prednisone on this lupus nephritis model may be partially mediated by the suppression of abnormal Akt- NF-κB activation.     

Effect of NOD8 on production of nitric oxide,IL-1β and TNF-α in LPS-treated macrophages

AIM: To investigate the effect of NOD8 on lipopolysaccharide (LPS)-induced releases of nitric oxide (NO), tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β) in RAW264.7 cells. METHODS: The plasmids of pEGFP-C2 and pEGFP-NOD8 were transfected into RAW264.7 cells respectively. The transfected and non-transfected cells were stimulated by LPS for 0, 6, 12 and 24 h. NO production was evaluated by Griess reagent assay, and the levels of IL-1β and TNF-α were measured by ELISA. The protein expression of NOD8 and the nuclear translocation of nuclear factor κB (NF-κB) p65 subunit were detected by Western blotting. The level of activated caspase-1 was determined by fluorimetric method. RESULTS: Compared with pEGFP-C2 group, the protein expression of NOD8 was significantly elevated in pEGFP-NOD8+LPS group. The releases of NO, IL-1β and TNF-α were obviously increased after RAW264.7 cells were treated with LPS for 6 h, 12 h and 24 h, and while the secretion of NO was significantly reduced in the cells transfected with pEGFP-NOD8 and induced by LPS for 12 h and 24 h, and the release of IL-1β was also significantly reduced at 6 h, 12 h and 24 h. However, no significant difference of TNF-α release was observed between pEGFP-C2+LPS group and pEGFP-NOD8+LPS group. The activation of caspase-1 in RAW264.7 cells stimulated with LPS for 6 h, 12 h and 24 h was markedly increased, and the expression of NF-κB p65 subunit in the cytoplasm was significantly decreased, indicating that p65 nuclear translocation was increased. In addition, the activation of caspase-1 and the nuclear translocation of p65 were significantly inhibited in pEGFP-NOD8+LPS group. CONCLUSION: NOD8 suppresses the releases of LPS-induced NO and IL-1β in RAW264.7 cells by inhibiting the activation of caspase-1 and NF-κB.     

Inhibitory effect of butylphthalide on apoptosis of hippocampal neurons in Alzheimer disease rats via SIRT1/NF-κB signaling pathway

AIM: To investigate the effect of butylphthalide on apoptosis of hippocampal neurons in Alzheimer disease (AD) rats via SIRT1/NF-κB signaling pathway and its mechanism. METHODS: AD rat model was established by intragastric administration of AlCl₃ and intraperitoneal injection of D-galactose. After treated with butylphthalide at 25 mg/kg (low dose), 50 mg/kg (medium dose) and 100 mg/kg (high dose), the effects of butylphthalide on the morphology of hippocampal neurons, apoptosis rate, and the protein levels of Bcl-2, Bax, cleaved caspase-3 and the SIRT1/NF-κB signaling pathway associated proteins were determined by HE staining, flow cytometry and Western blot, respectively. After treated with SIRT1 agonist SRT1720 and inhibitor sirtinol, the role of SIRT1/NF-κB signaling pathway in hippocampal neuronal apoptosis was observed. On the basis of giving 50 mg/kg butylphthalide, sirtinol was administered, and the effect of butylphthalide on neuronal apoptosis regulated by SIRT1/NF-κB signaling pathway was evaluated. RESULTS: The morphology of hippocampal neurons in the AD rats were improved, the apoptosis rate of hippocampal neurons and the protein levels of Bax and cleaved caspase-3 were inhibited, and the protein levels of Bcl-2 and the activation of SIRT1/NF-κB signaling pathway were promoted by butylphthalide significantly (P<0.05). The protein expression of Bcl-2 and the activation of SIRT1/NF-κB signaling pathway were promoted, and the apoptosis of hippocampal neurons and the protein levels of Bax and cleaved caspase-3 were inhibited by SRT1720 remarkably (P<0.05), whereas the effect of sirtinol was contrary to that of SRT1720. After sirtinol treatment, the inhibitory effect of butylphthalide on apoptosis of hippocampal neurons, the protein levels of Bax and cleaved caspase-3, and the promotion of Bcl-2 protein expression in hippocampal neurons were markedly weakened (P<0.05). CONCLUSION: Butylphthalide inhibits the apoptosis of hippocampal neurons in the AD rats by down-regulating the protein expression of Bax and cleaved caspase-3, and up-regulating the protein expression of Bcl-2 through activating SIRT1/NF-κB signaling pathway.     

Klebsiella pneumoniae capsular polysaccharide induces secretion of cytokines in bronchial epithelial cells via EGFR signaling pathway

AIM: To investigate the role of epidermal growth factor receptor (EGFR) in the secretion of inflammatory cytokines in human bronchial epithelial BEAS-2B cells induced by Klebsiella pneumoniae (KP) capsular polysaccharide (CPS). METHODS: KP was cultured in vitro, and the CPS was extracted. The BEAS-2B cells were stimulated with CPS at different concentrations, and the levels of tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) in the supernatant were measured by ELISA. The phosphorylation level of EGFR was detected by Western blot at different time points after stimulation. After pretreatment of the BEAS-2B cells with EGFR inhibitor AG1478, the phosphorylation level of ERK was detected by Western blot, the nuclear translocation of P65 was detected by indirect immunofluorescence, and the levels of TNF-α and IL-8 in the supernatant of the cells were measured. Finally, the levels of TNF-α and IL-8 in the culture supernatant of CPS-stimulated cells were detected by ELISA after pretreated with ERK inhibitor PD98059 and NF-κB inhibitor PDTC. RESULTS: Exposure to CPS at 10 mg/L for 12 h significantly induced the BEAS-2B cells to secret TNF-α and IL-8. The phosphorylation levels of EGFR and ERK and the nuclear translocation of p65 in the BEAS-2B cells were significantly increased after CPS stimulation (P<0.05). The phosphorylation level of ERK and the nuclear translocation of p65 were significantly reduced in the cells pretreated with EGFR inhibitor AG1478. Furthermore, the levels of TNF-α and IL-8 in the supernatant were significantly decreased after pretreated with the inhibitors of EGFR, ERK and NF-κB. CONCLUSION: Klebsiella pneumonia capsular polysaccharide activates the ERK and NF-κB signaling pathways via EGFR, and then induced the secretion of inflammatory cytokines TNF-α and IL-8 in the bronchial epithelial cells, indicating that EGFR may be a key factor in the inflammatory response induced by KP infection.     

Effect of tea-polyphenols on the activation of NF-κB and the expression of TGF-β1 mRNA in THP-1 cells incubated with VLDL,LDL or ox-LDL

AIM:To investigate the effect of tea-polyphenols (TP) on the activation of NF-κB and the expression of TGF-β₁ mRNA in THP-1 cells (a human acute monocytic leukemia cell line). METHODS:THP-1 cells were incubated with the different concentrations of TP, VLDL, LDL or ox-LDL. In the THP-1 cellls, the nuclear malposition rate of NF-κB was detected with immunohistochemistry technique, the positive index of the TGF-β₁ mRNA expression was detected by hybridization in situ, and accumulation of total cholesterol (TC) in cells incubated with 0.4-40 μg/L TP was determined with oxidase assay. RESULTS:The nuclear malposition rate of NF-κB, the positive index of the TGF-β₁ mRNA expression and TC in THP-1 cells incubated with 0.4-40 μg/L of TP were lower than those with 0 μg/L of TP in TP-V group, TP-L group and TP-O (P＜0.05). The differences of these markers in THP-1 cells incubated with more than 40 μg/L TP in TP-V group, TP-L group and TP-O were not statistically significant, compared with TP-C group (P＞0.05). CONCLUSION:TP inhibited the activation of NF-κB, the expression of TGF-β₁ mRNA and the foam cell formation in the mono-macrophage.     

Epidermal growth factor receptor pathway participates in growth promotion of chondrocytes by growth hormone from sex hormone-inhibited adolescent rats

AIM: To investigate the possibility that epidermal growth factor receptor pathway participates in the growth promotion by growth hormone (GH) of growth plate chondrocytes cultured in vitro from adolescent rats treated with gonadotropin-releasing hormone analogue (GnRHa). METHODS: The chondrocytes from tibial growth plate of 5-8 female Sprague-Dawley (SD) rats treated with GnRHa were cultured in monolayer. Specific pharmacological inhibitor of Janus kinase (JAK2 tyrphostin AG490, 1, 10, 100 nmol/L), EGFR kinase inhibitor AG1478 (0.1, 1, 10 nmol/L) and neutralizing antibodies against EGF (0.1, 1, 10 mg/L) were added before GH stimulation. The proliferation of chondrocytes was investigated by the methods of MTT and immunohistochemical staining for PCNA. Phosphorylations of ERK1/2 and EGFR were detected by Western blotting. RESULTS: GH enhanced the proliferation of chondrocytes and the levels of ERK1/2 and EGFR phosphorylation in a dose dependent manner. The effect peaked at the concentration of 100 μg/L. Pretreatment with tyrphostin AG490 and AG1478 almost completely inhibited the proliferation of chondrocytes and phosphorylation of ERK1/2 and EGFR by GH. However, the neutralizing antibodies against EGF only partially inhibited the effects of GH.CONCLUSION: GH achieves its direct effect on the promotion of cell proliferation by the activation of JAK2 pathway and the downstream end of MAPK-ERK signaling molecules. The promotion of cell proliferation can be mediated by activation of EGFR pathway. The results suggest that there is signaling cross-talk between GH and EGF-EGFR pathway.     

Signaling mechanism of dendritic cell maturation stimulated by uric acid

AIM: To investigate the effect of uric acid on the signal molecule expression involved in MAPKs and NF-κB pathways during the maturation of dendritic cells (DCs). METHODS: DCs were obtained from murine bone-marrow and cultured in vitro. After the immature DCs were stimulated with uric acid (200 mg/L) and NF-κB inhibitor PDTC, or MAPKs inhibitors SB203580, PD98059 or SP600125 for 15 min, 30 min or 45 min, the cytoplasmic and nuclear extracts of the cells were collected and were subject to immunoblot analysis with the antibodies specific for NF-κB p65 or phosphorylated forms of p38, ERK1/2 and JNK. The cell lysates from DCs treated with LPS or DMSO served as controls. After treated with uric acid and PDTC, SB203580, PD98059 or SP600125 for 48 h, DCs were collected. The cell surface markers were analyzed by flow cytometry. The production of IL-12 p70 in the culture supernatants was detected by ELISA. RESULTS: Within 15 min of uric acid conditioning in the immature DCs, increased expression of NF-κB p65 and the phosphorylation of p38, ERK1/2 and JNK in the nuclear or cytoplasmic extracts of DCs were observed. The expression of these proteins reached their peak at 30 min after stimulation. Pretreatment of DCs with PDTC, SB203580, SP600125 or PD98059 blocked the expression of NF-κB p65 and phosphorylation of p38, ERK1/2 and JNK in response to uric acid stimulation. Treatment of DCs with SB203580, SP600125 or PDTC reduced the uric acid-induced up-regulation of CD83, CD86 and IA/IE, and inhibited the effect of uric acid on the secretion of IL-12 p70 (P<0.05 or P<0.01). SB203580 and PDTC possessed a significant inhibitory effect on uric acid. Nevertheless, PD98059 increased the up-regulation of CD83, CD86, IA/IE and IL-12 p70 induced by uric acid (P<0.05). CONCLUSION: Uric acid controls the balance of signal molecule phosphorylation of p38 MAPK, ERK1/2 and JNK, and NF-κB pathways. A possible mechanism of the DCs maturation stimulated by uric acid may be the modulation of the threshold and duration of MAPKs and NF-κB signaling.     

Expression of cyclooxygenase-2 in IL-1β-stimulated mesangial cells is medicated by NF-κB/IκB signal pathway

AIM: To investigate the role of NF-κB/IκB signal pathway in the regulation of cyclooxygenase-2 (COX-2) expression in human mesangial cells (HMC). METHODS: The PGE₂ concentration in supernatants of HMC was measured by radioimmunoassay. COX-2 mRNA and protein expression were determined by RT-PCR and Western blot. Electrophoretic mobility shift assay (EMSA) and Western blot were used to detect the activity of NF-κB and degradation of IκB. RESULTS: IL-1β significantly upregulated COX-2 expression and PGE₂ production in HMC. Significant up-regulation of NF-κB activation, nuclear translocation of p65 subunit, and degradation of IκB α and IκB β were observed in IL-1β-induced HMC. CONCLUSION: Expression of COX-2 in IL-1β-induced HMC is mediated by NF-κB/IκB signal pathway.     

Oxidized α1-antitrypsin induces IL-8 and MCP-1 production in HBE cells

AIM:To investigate the effect of oxidized α1-antitrypsin (Ox-AT) on interleukin 8 (IL-8) and monocyte chemotactic protein 1(MCP-1) production in cultured human bronchial epithelial (HBE) cells. METHODS:Plasma native α1-antitrypsin (N-AT) was purified from human plasma by 50% and 75% ammonium sulfate fractionation followed by glutathione and anion exchange chromatography. Ox-AT was prepared by incubating N-AT (0.5 g/L) with N-chlorosuccinimide in a 25-fold molar excess to N-AT in PBS at room temperature for 30 min. HBE cells were cultured in the presence of Ox-AT (0.5 g/L) for 4 h, 10 h and 24 h, and the levels of IL-8 and MCP-1 in the supernatant were assayed using respective DuoSet kits. The effect of NF-κB inhibitor Bay11-7082 on the inflammatory cytokine release induced by Ox-AT was also evaluated. RESULTS:Ox-AT concentration-dependently and time-dependently increased the production of IL-8 and MCP-1 in HBE cells. The concentrations of IL-8 and MCP-1 in HBE cells induced by 0.5 g/L Ox-AT at 4 h, 10 h and 24 h were significantly higher than those in blank control and N-AT groups. Ox-AT increased the activity of NF-κB in a dose-dependent manner. The proinflammatory effect of by Ox-AT was inhibited by NF-κB inhibitor Bay11-7082. CONCLUSION: Ox-AT is a strong proinflammatory factor for HBE cells. The mechanism is related to NF-κB signaling pathway activation.     

Combined effect of octreotide and Dachaihu decoction on treatment of severe acute pancreatitis

AIM: To investigate the combined effect of octreotide and Dachaihu decoction on the treatment of severe acute pancreatitis(SAP). METHODS: Wistar rats(n=50) were randomly divided into sham group, SAP group, octreotide group, Dachaihu decoction group and combination group. The quantity of ascites was measured. The levels of amylase, alanine aminotransferase and creatinine in the serum were examined. The morphological changes of the pancreatic tissues were observed by HE staining. The activation of NF-κB and IκBα expression were determined by Western blot. The mRNA expression with ICAM-1 and IL-1 was detected by qPCR.RESULTS: Combined treatment with octreotide and Dachaihu decoction effectively reduced the quantity of ascites and the levels of amylase, alanine aminotransferase and creatinine in the serum in SAP rats. Moreover, combined treatment significantly inhibited SAP-induced activation of NF-κB and decrease in IκBα protein expression, accompanied by a decrease in ICAM-1 and IL-1 mRNA expression. CONCLUSION: Combination of octreotide with Dachaihu decoction effectively attenuates SAP by inhibiting NF-κB signaling pathway and ICAM-1 and IL-1 expression.     

Role of TLR4-TRPC6 in LPS-induced NF-κB P65 expression and nuclear translocation in airway epithelial 16HBE cells

AIM: To investigate the role of Toll-like receptor 4 (TLR4) and transient receptor potential channel 6 (TRPC6) signaling pathway in lipopolysaccharide (LPS)-induced nuclear factor-κB (NF-κB) P65 expression and nuclear translocation in airway epithelial cells (16HBE) for supplementing the mechanism for airway inflammation. METHODS: After stimulating the 16HBE cells with LPS at 1 mg/L for 0, 0.5, 2, 6, 12 and 24 h, the expression of NF-κB P65 at mRNA and protein levels in the 16HBE cells were determined by RT-PCR and Western blot respectively, and the nuclear translocation of NF-κB P65 was detected by immunocytochemical staining method. The effects of TLR4 inhibitor CLI-095 at 5 μmol/L and TRPC6 agonist Hyp9 at 10 μmol/L on LPS (1 mg/L)-induced NF-κB P65 expression and nuclear translocation in the 16HBE cells were determined by RT-PCR, Western blot and immunocytochemical staining. RESULTS: LPS increased the mRNA and protein expression of NF-κB P65 and nuclear translocation in the 16HBE cells(P<0.05). TLR4 inhibitor CLI-095 reduced the mRNA and protein expression of NF-κB P65 and nuclear translocation induced by LPS, while Hyp9 enhanced the mRNA and protein expression of NF-κB P65 and nuclear translocation induced by LPS in the 16HBE cells(P<0.05). CONCLUSION: LPS induces the expression and nuclear translocation of NF-κB P65 in the 16HBE cells via TLR4-TRPC6 signaling pathway.     

Inhibitory effect of madecassoside on LPS-stimulated microglia

AIM: To observe the inhibitory effect of madecassoside on the LPS-stimulated microglia and to investigate its possible mechanism. METHODS: Microglia cells of neonatal Sprague-Dawley (SD) rats were cultured, isolated and purified. Microglia cells were activated with lipopolysaccharide (LPS). The inhibitory effect of madecassoside on microglia was measured by MTT assay. Tumor necrosis factor alpha (TNF-α), interleukin 1β (IL-1β) were detected by ELISA. Cell cycle and apoptotic rate were evaluated by flow cytometry. The expression of TLR4 was detected by Western blotting. The expression of NF-κB was detected by RT-PCR. RESULTS: LPS induced the proliferation of microglia and release inflammatory cytokines significantly. Compared with LPS group, madecassoside inhibited the proliferation of microglia induced by LPS in a dose dependent manner. The IC₅₀ value of madecassoside was 10.97 nmol/L to microglia after incubation for 48 h. Madecassoside also decreased the levels of TNF-α and IL-6, increased the ratios of microglia at the G₂ phase and the apoptotic rate, decreased the expression of TLR4 and NF-κB significantly (P<0.05). CONCLUSION: Madecassoside has inhibitory effects on the proliferation of LPS-stimulated microglia, by which the mechanism may be related to inhibition of the expression of TLR4 and NF-κB, change of cell cycle distribution and induction of microglia apoptosis.     

Activation of NF-κB in rat vascular smooth muscle cells by autoantibodies against α1-adrenergic receptor from hypertensive patients

AIM：To study the effects of autoantibodies against α1-adrenergic receptor (α1-AAs) isolated from the hypertensive patients, which showed the agonist-like activity similar to norepinephrine, on the signal mechanism of vascular smooth muscle cells (VSMCs) isolated from rat thoracic aorta. METHODS：Rat VSMCs were cultured and identified. The serum of hypertensive patients was purified by immunoaffinity chromatography. The autoantibodies were detected by ELISA and used to activate the cells with the titer of 1∶80. The total protein was extracted and the expression of NF-κB in different treatment groups was detected by Western blotting. Meanwhile, the activation of NF-κB in the nucleus was analyzed by immunofluorescence method. RESULTS：The expression of NF-κB in VSMCs was obviously higher in α1-AAs group than that in control group. Meanwhile, the expression of NF-κB was inhibited by prasozin and PDTC. The autoantibodies caused a significant increase in NF-κB expression in the nucleus. The fluorescence intensity in α1-AAs group was high than that in control group and α1-AAs+prasozin group (P<0.01). CONCLUSION:The α1-AAs from hypertensive patients increase NF-κB expression in rat VSMCs.     

Role of Akt/NF-κB pathway in immune-complexes-induced MCP-1 and CSF-1 expression in murine glomerular mesangial cells

AIM: To explore the role of Akt/NF-κB pathway in immune-complexes-induced monocyte chemoattractant protein-1 (MCP-1) and colony stimulating factor-1 (CSF-1) expression in Mesangial Cells. METHODS: Primary murine glomerular mesangial cells were cultured in vitro and divided into control group, stimulation group and antisense, sense and mismatched oligodeoxynucleotide group. In control group, the cells were stimulated with monomeric IgG after treatment with 0.5% lipofectin for 8 h. In stimulation group, the cells, which had been treated with 0.5% lipofectin for 8 h, were stimulated with aggregated IgG. In antisense, sense and mismatched oligodeoxynucleotide group, being transduced antisense, sense and mismatched oligodeoxynucleotide respectively with 0.5% lipofectin 8 h, the cells were stimulated with AIgG. MCP-1 and CSF-1 in supernatant were deteced with ELISA. In addition, RT-PCR was used to determine MCP-1 and CSF-1 mRNA expression, and EMSA to investigated the activation of NF-κB. RESULTS: Mesangial cells cultured in vitro had a low level NF-κB activation and a low level constitutive expression of MCP-1 and CSF-1. Stimulated with AIgG, activation of NF-κB was markedly increased(0.35±0.06 vs 0.75±0.16, P＜0.01), expression of MCP-1 and CSF-1 mRNA (0.48±0.03 vs 0.72±0.02, P＜0.05; 0.44±0.01 vs 0.59±0.02, P＜0.05), MCP-1 and CSF-1 levels in supernatant(15.52±1.81 vs 43.05±3.18, P＜0.05; 389.06±13.75 vs 764.22±31.78, P＜0.05) were markedly increased. Akt1 antisense oligodeoxynucleotide markedly inhibited immune-complexes-induced NF-κB activation, MCP-1 and CSF-1 mRNA and protein expression. CONCLUSION: Akt/NF-κB pathway mediates immune-complexes-induced MCP-1 and CSF-1 expression in mesangial cells. It suggests that Akt/NF-κB pathway may be a new therapy target for macrophage recruitment and activation in immune complexes nephritis.     

Expression of nuclear factor-κB in asthmatic guinea pigs and the effect of erigeron breviscapus on it

AIM:To explore the expression of nuclear factor-κB(NF-κB)in asthmatic guinea pigs,and the effect of erigeron breviscapus,a protein kinase C(PKC)inhibitor,on the expression of nuclear factor-κB(NF-κB).METHODS:48 guinea pigs were randomly divided into 6 groups(n=8).Airway resistance and eosinophilic inflammation of airway wall were examined,the expression of NF-κB in the lung tissue was detected by immunohistochemical staining.RESULTS:The expression of NF-κB was mainly found in airway epithelium,all the asthmatic animals showed significantly higher optical densities than that of the normal control group(P＜0.01),and the rats subjected therapeutic treatment for two weeks showed significantly lower NF-κB expression than those of the asthmatic groups(P＜0.01).Positive correlation exist between the airway resistance and the percentage of cells expressing NF-κB in epithelium,and between the amount of eosinophil in airway wall and the percentage of cells expressing NF-κB in epithelium(P＜0101).CONCLUSION:The increased expression of NF-κB in airway epithelium of the asthmatic guinea pigs suggested that NF-κB may be involved in asthma.And result that the increased expression of NF-κB was inhibited significantly by the treatment of the erigeron breviscapus suggested that PKC may play a significant role in the pathogenesis of asthma through NF-κB.     

Effect of toosendanin on invasion and migration of human ovarian cancer cells

AIM: To investigate the effect of toosendanin (TSN) on invasion and migration abilities of human ovarian cancer cells and the related mechanism. METHODS: The human ovarian cancer cell lines CAVO-3 and SKVO-3 were treated with TSN at different concentrations. The cell viabilty at 12, 24, 48, 72 and 96 h after TSN treatment was measured by CCK-8 assay. Scratch wound healing assay and Transwell assay were employed to measure the invasion and migration abilities of CAVO-3 cells. The protein expression of nuclear factor-κB (NF-κB) p65, E-cadherin, N-cadherin, vimentin and Snail was determined by Western blot. RESULTS: TSN significantly inhibited the viability of CAVO-3 and SKVO-3 cells (P<0.05). Compared with control group, the migration and invasion abilities of CAVO-3 cells in TSN group decreased significantly (P<0.05). In addition, the expression of NF-κB p65 and E-cadherin protein increased notably, followed with N-cadherin, vimentin and Snail protein decreased significantly (P<0.05). However, the inhibitor of NF-κB BAY11-7082 reversed the impact above. Compared with TSN group, the migration and invasion abilities in TSN+BAY11-7082 group increased significantly (P<0.05). The protein expression of E-cadherin also decreased notably, followed with the protein expression of N-cadherin, vimentin and Snail increased significantly (P<0.05). CONCLUSION: TSN inhibits the invasion and migration abilities of human ovarian cancer cells, which is related to the inhibition of epithelial-mesenchymal transition process mediated by NF-κB/Snail signaling pathway.     

Regulation of ectopic trypsin and proinflammatory cytokine expression by NF-κB and AP-1 in influenza A virus induced myocarditis

AIM: To investigate the regulatory effects of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) on the expression of ectopic trypsin and proinflammatory cytokines in influenza A virus (IAV)-induced myocarditis. METHODS: Male BALB/c mice of 8 weeks old (n=40) were randomly divided into 4 groups: normal control group (NC), infection control group (IC), NF-κB inhibitor group (NI) and AP-1 inhibitor group (AI). The mice in NC group and IC group were instilled intranasally with 15 μL saline and 40 plaque forming units (PFU) IAV, respectively. The mice in NI group and AI group were infected intranasally with 40 PFU IAV and injected intraperitoneally with 10 mg/kg NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) or 2.5 mg/kg AP-1 inhibitor nordihydroguaiaretic acid (NDGA) once daily. The mice were euthanized at day 9 after instillation, and the hearts were removed for pathological and biochemical analysis. RESULTS: IAV infection induced significant up-regulation of ectopic trypsin, and proinflammatory cytokines interleukin 6 (IL-6), IL-1β and tumor necrosis factor-α (TNF-α) in the myocardium, and triggered acute myocarditis. PDTC significantly inhibited NF-κB activation and up-regulation of ectopic trypsin and proinflammatory cytokines, and effectively suppressed IAV replication and myocardial inflammatory response (P<0.01). NDGA effectively inhibited AP-1 activity (P<0.01) and mildly suppressed up-regulation of proinflammatory cytokines (P<0.05), but had no effects on the expression of ectopic trypsin, IAV replication and the extent of myocarditis (P>0.05). CONCLUSION: IAV infection induces up-regulation of ectopic trypsin and proinflammatory cytokines in myocardium predominantly by the activation of NF-κB. AP-1 signaling pathway might be only partially involved in the regulation of proinflammatory cytokines.