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1.
AIM: To investigate the effect of Tetrandrine (Tet) on LPS-induced NF-κB activation and cell injury in pancreatic acinar cells and to explore the mechanism of Tetrandrine preventing LPS-induced acinar cell injury. METHODS: Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to LPS (10 mg/L), Tet (50μmol/L, 100μmol/L) or normal media. At different time point (30 min, 1 h, 4 h, 10 h) after treatment with the agents, cell viability was determined by MTT, the product and nuclear translocation of subunit p65 of NF-κB was visualized by immunofluorescence staining and nuclear protein was extracted to perform EMSA which was used to assay the NF-κB binding activity. RESULTS: LPS induced cell damage directly in a time dependent manner and Tet attenuated LPS-induced cell damage (50μmol/L, P < 0.05; 100μmol/L, P < 0.01). NF-κB p65 immunofluorescence staining in cytoplasm increased and began showing its nuclear translocation within 30 min and the peak was shown at 1 h of LPS 10 mg/L treatment. NF-κB DNA binding activity showed the same alteration pattern as p65 immunofluorescence staining. In Tet group, the immunofluorescence staining in cytoplasm and nuclear translocation of NF-κB were inhibited significantly. CONCLUSION: NF-κB activation is an important early event that may contribute to inflammatory responses and cell injury in pancreatic acinar cells. Tet possesses the protective effect on LPS-induced acinar cell injury by inhibiting NF-κB activation.  相似文献   

2.
AIM:This investigation was to reveal the characteristics and mechanism of enzyme secretion and increase in [Ca^2+]i stimulated by saikosaponin(1)[SA(1)] in rat pancreatic acini.METHODS:Pancreatic acini were prepared from male Wistar rats.Isolated acinar cells were suspended in Eagle‘s MEM solution,After adding drugs,the incubation was performed at 37℃for a set period of time.Amylase of supermatant was assayed using starch-iodide reaction.Isolated acinar single cell was incubated with Fura-2/AM at 37℃,then cells were wasthed and resuspended in fresh sulution and attached to the chamber,Cytoplasm [Ca^2+]i of a single cell was expressed by fluorescence ratio F340/F380 recorded in a Nikon PI Cd^2+ measurement system.RESULTS:Rate course of amylase secretion stimulated by SA(I) in rat pancreatic acini appeared in bell-like shape,The peak amplitude increased depended on SA(I) concentration.The maximum rate responded to 1^10moll/L SA(I) was 13.1-forld of basal and the rate decreased to basal level at 30min.CCK-8 receptor antagonist Bt2-cGMP markedly inhibited amylase secretion stimulated by SA(I)and the dose-effect relationship was similar th that by CCK-8,[Ca^2+]i in a single acinar cell rose to the peak at 5min afer adding 5&#215;10^-6mol/L SA(I) and was 5.1-fold of basal level.In addition,there was a secondary increase after the initial peak.GDP could inhibit both the rate of amylase secretion and rising of [Ca^2+]i stmulated by SA(I) in a single pancreatic acinar cell.  相似文献   

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AIM: Different strains of bifidobacteria were analysed for their effects on HT-29 intestinal epithelial cells (IECs) in in vitro models both of the non-inflamed and inflamed intestinal epithelium. METHODS: A reporter gene system in HT-29 cells was used to measure levels of NF-KB activation after challenge with bifidobacteria or after bacterial pre-treatment following LPS challenge. IL-8 protein and pro-inflammatory gene expression was investigated using normal HT-29 cells. RESULTS: None of the bifidobacteria tested induced activation of nuclear factor KB (NF-KB) indicating that bifidobacteria themselves do not induce inflammatory events in IECs. However, six out of eight bifidobacteria tested inhibited lipopolysaccharide- (LPS-) induced NFKB activation in a dose- and strain-dependent manner. In contrast, NF-KB activation in response to challenge with tumor necrosis factor-α(TNF-α) was affected by none of the tested bifidobacteria, indicating that the inhibitory effect of bifidobacteria is specific for LPS-induced inflammation in IECs. As shown with two of the six inhibitionpositive bifidobacteria, LPS-induced inhibition of NFKB activation was accompanied by a dose-dependent decrease of interleukin 8 (IL-8) secretion and by lower mRNA levels for IL-8, TNF-a, cyclooxygenase 2 (Cox-2), and intercellular adhesion molecule 1 (ICAM-1). CONCLUSION: Some strains of bifidobacteria are effective in inhibiting LPS-induced inflammation and thus might be appropriate candidates for probiotic intervention in chronic intestinal inflammation.  相似文献   

5.
AIM: Different strains of bifidobacteria were analysed for their effects on HT-29 intestinal epithelial cells (IECs) in in vitro models both of the non-inflamed and inflamed intestinal epithelium. METHODS: A reporter gene system in HT-29 cells was used to measure levels of NF-kappaB activation after challenge with bifidobacteria or after bacterial pre-treatment following LPS challenge. IL-8 protein and pro-inflammatory gene expression was investigated using normal HT-29 cells. RESULTS: None of the bifidobacteria tested induced activation of nuclear factor kappaB (NF-kappaB) indicating that bifidobacteria themselves do not induce inflammatory events in IECs. However, six out of eight bifidobacteria tested inhibited lipopolysaccharide- (LPS-) induced NF-kappaB activation in a dose- and strain-dependent manner. In contrast, NF-kappaB activation in response to challenge with tumor necrosis factor-alpha (TNF-alpha) was affected by none of the tested bifidobacteria, indicating that the inhibitory effect of bifidobacteria is specific for LPS-induced inflammation in IECs. As shown with two of the six inhibition-positive bifidobacteria, LPS-induced inhibition of NF-kappaB activation was accompanied by a dose-dependent decrease of interleukin 8 (IL-8) secretion and by lower mRNA levels for IL-8, TNF-alpha, cyclooxygenase 2 (Cox-2), and intercellular adhesion molecule 1 (ICAM-1). CONCLUSION: Some strains of bifidobacteria are effective in inhibiting LPS-induced inflammation and thus might be appropriate candidates for probiotic intervention in chronic intestinal inflammation.  相似文献   

6.
AIM: To investigate the effect of various concentrations of tetrandrine on activation of quiescent rat hepatic stellate cells (HSCs) and transforming growth factor-β (TGF-β) signaling in vitro. METHODS: HSCs were isolated from rats by in situ perfusion of liver and 18% Nycodenz gradient centrifugugation, and primarily cultured on uncoated plastic plates for 24 h with DMEM containing 20% fetal bovine serum (FBS/DMEM) before the culture medium was substituted with 2% FBS/DMEM for another 24 h. Then, the HSCs were cultured in 2% FBS/DMEM with tetrandrine (0.25, 0.5, 1,2 mg/L, respectively). Cell morphological features were observed under an inverted microscope, smooth muscle-α-actin (α-SMA) was detected by immunocytochemistry and image analysis system, laminin (LN) and type Ⅲ procollagen (PCⅢ) in supernatants were determined by radioimmunoassay. TGF-β1 mRNA, Smad 7 mRNA and Smad 7 protein were analyzed with RT-PCR and Western blotting, respectively. RESULTS: Tetrandrine at the concentrations of 0.25-2 mg/L prevented morphological transformation of HSC from the quiescent state to the activated one, while α-SMA, LN and PCⅢ expressions were inhibited. As estimated by gray values, the expression of α-SMA in tetrandrine groups (0.25, 0.5, 1, 2 mg/L) was reduced from 21.3% to 42.2% (control: 0.67, tetrandrine groups: 0.82, 0.85, 0.96, or 0.96, respectively, which were statistically different from the control, P&lt;0.01), and the difference was more significant in tetrandrine at 1 and 2 mg/L. The content of LN in supernatants was significantly decreased in tetrandrine groups to 58.5%, 69.1%, 65.8% or 60.0% that of the control respectively, and that of PCII] to 84.6%, 81.5%, 75.7% or 80.7% respectively (P&lt;0.05 vs control), with no significant difference among tetrandrine groups. RTPCR showed that TGF-β1 mRNA expression was reduced by tetrandrine treatments from 56.56% to 87.90% in comparison with the control, while Smad 7 mRNA was increased 1.4-4.8 times. The TGF-β1 mRNA and Smad 7 mRNA expression was in a significant negative correlation (r = -0.755, P&lt;0.01), and both were significantly correlated with α-SMA protein expression (r = -0.938, P&lt;0.01; r = 0.938, P&lt;0.01, respectively). The up-regulation of Smad 7 protein by tetrandrine (1 mg/L) was confirmed by Western blotting as well. CONCLUSION: Tetrandrine has a direct inhibiting effect on the activation of rat HSCs in culture. It up-regulates the expression of Smad 7 which in turn blocks TGF-β1 expression and signaling.  相似文献   

7.
Background: Previous studies have provided conflicting results regarding whether the serum ghrelin concentration can reflect the severity of acute pancreatitis(AP). The present study examined the correlation between the serum ghrelin concentration and AP severity in animal models and investigated whether altered ghrelin expression in pancreatic acinar cells influences IKK β/NF-κ B signaling and pro-inflammatory cytokine production. Methods: Mild or severe AP was induced in rats by intraperitoneal injection of cerulein or retrograde cholangiopancreatic duct injection of sodium taurocholate, respectively. After successful model induction, serum ghrelin, tumor necrosis factor-α(TNF-α), and interleukin-6(IL-6) concentrations were determined by enzyme-linked immunosorbent assay, and IKK β/NF-κ B activation was assessed by immunohistochemistry. Subsequently, stable overexpression or knockdown of ghrelin in AR42 J cells was achieved by lentiviral transfection. After transfected cells and control cells were treated with cerulein for 24 h, the TNF-αand IL-1 β levels in the supernatants were determined by enzyme-linked immunosorbent assay, and the expression levels of p-p65, IKK β, and p-IKK β were detected by Western blotting. Results: In rat AP models, AP severity was correlated with increased IKK β/NF-κ B activation, proinflammatory cytokine production, and ghrelin secretion. The levels of pro-inflammatory cytokines TNF-αand IL-1 β as well as IKK β/NF-κ B signaling activity were increased upon knockdown of ghrelin in the AP acinar cell model and decreased with ghrelin overexpression. Conclusions: Serum ghrelin is related to the severity of AP. Ghrelin may play a protective role in the pathogenesis of AP by inhibiting the pro-inflammatory cytokines and the activation of the IKK β/NF-κ B signaling pathway.  相似文献   

8.
A number of studies have recently demonstrated the involvement of nuclear factor-kappa B (NF-κB) activation and the subsequent coordinated inflammatory responses in the pathogenesis of diabetic nephropathy (DN). Polydatin has been shown to have the ability of anti-adhesive inflammation. However, the possible protective and beneficial effects of polydatin on DN via suppressing inflammatory damage and extracellular matrix (ECM) accumulation are not fully elucidated. We found that the polydatin could inhibit the induction and activity of NF-κB, and meanwhile ameliorating ECM accumulation in streptozotocin-diabetic rats. We aimed to investigate the effect of polydatin on fibronectin (FN) protein expression, and to elucidate its potential mechanism involving the NF-κB inflammatory signaling pathway in rat glomerular mesangial cells (GMCs) cultured under high glucose. The results revealed that polydatin significantly suppressed high glucose-induced FN production, inhibited NF-κB nuclear translocation, reduced the DNA-binding activity of NF-κB, as well as decreased the protein expression of ICAM-1 and TGF-β in GMCs. These findings suggested that polydatin significantly represses high glucose-induced FN expression in rat GMCs, which may be closely related to its inhibition of the NF-κB signaling pathway. Hence, we elucidated the potential mechanisms of the anti-inflammatory effects and ECM accumulation alleviation of polydatin in GMCs of DN in vitro.  相似文献   

9.
AIM: To investigate the effect of various concentrations of tetrandrine on activation of quiescent rat hepatic stellate cells (HSCs) and transforming growth factor-β(TGF-β) signaling in vitro. METHODS: HSCs were isolated from rats by in situ perfusion of liver and 18% Nycodenz gradient centrifugation, and primarily cultured on uncoated plastic plates for 24 h with DMEM containing 20% fetal bovine serum (FBS/ DMEM) before the culture medium was substituted with 2% FBS/DMEM for another 24 h. Then, the HSCs were cultured in 2% FBS/DMEM with tetrandrine (0.25, 0.5, 1, 2 mg/L, respectively). Cell morphological features were observed under an inverted microscope, smooth muscle-α-actin (α-SMA) was detected by immunocytochemistry and image analysis system, laminin (LN) and type Ⅲ procollagen (PCⅢ) in supernatants were determined by radioimmunoassay. TGF-β1 mRNA, Smad 7 mRNA and Smad 7 protein were analyzed with RT-PCR and Western blotting, respectively. RESULTS: Tetrandrine at the concentrations of 0.25-2 mg/L prevented morphological transformation of HSC from the quiescent state to the activated one, while α-SMA, LN and PCⅢ expressions were inhibited. As estimated by gray values, the expression of α-SMA in tetrandrine groups (0.25, 0.5, 1, 2 mg/L) was reduced from 21.3% to 42.2% (control: 0.67, tetrandrine groups: 0.82, 0.85, 0.96, or 0.96, respectively, which were statistically different from the control, P<0.01), and the difference was more significant in tetrandrine at 1 and 2 mg/L. The content of LN in supernatants was significantly decreased in tetrandrine groups to 58.5%, 69.1%, 65.8% or 60.0% that of the control respectively, and that of PCⅢ to 84.6%, 81.5%, 75.7% or 80.7% respectively (P<0.05 vs control), with no significant difference among tetrandrine groups. RT-PCR showed that TGF-β1 mRNA expression was reduced by tetrandrine treatments from 56.56% to 87.90% in comparison with the control, while Smad 7 mRNA was increased 1.4-4.8 times. The TGF-β1 mRNA and Smad 7 mRNA expression was in a significant negative correlation (r= -0.755, P<0.01), and both were significantly correlated with α-SMA protein expression (r= -0.938, P<0.01; r = 0.938,P<0.01, respectively). The up-regulation of Smad 7 protein by tetrandrine (1 mg/L) was confirmed by Western blotting as well. CONCLUSION: Tetrandrine has a direct inhibiting effect on the activation of rat HSCs in culture. It up-regulates the expression of Smad 7 which in turn blocks TGF-β1 expression and signaling.  相似文献   

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AIM: To investigate the effect of Tetrandrine (Tet) on LPS-induced NF-κB activation and cell injury in pancreatic acinar cells and to explore the mechanism of Tetrandrine preventing LPS-induced acinar cell injury.METHODS: Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to LPS (10mg/L), Tet (50 μmol/L, 100 μmol/L) or normal media. At different time point (30 min, 1 h, 4 h, 10 h) after treatment with the agents, cell viability was determined by MTT, the product and nuclear translocation of subunit p65 of NF-κB was visualized by immunofluorescence staining and nuclear protein was extracted to perform EMSA which was used to assay the NF-κB binding activity.RESULTS: LPS induced cell damage directly in a time dependent manner and Tet attenuated LPS-induced cell damage (50 μmol/L, P < 0.05; 100 μmol/L, P < 0.01).NF-κB p65 immunofluorescence staining in cytoplasm increased and began showing its nuclear translocation within 30 min and the peak was shown at 1 h of LPS 10 mg/L treatment. NF-κB DNA binding activity showed the same alteration pattern as p65 immunofluorescence staining. In Tet group, the immunofluorescence staining in cytoplasm and nuclear translocation of NF-κB were inhibited significantly.CONCLUSION: NF-κB activation is an important early event that may contribute to inflammatory responses and cell injury in pancreatic acinar cells. Tet possesses the protective effect on LPS-induced acinar cell injury by inhibiting NF-κB activation.  相似文献   

12.
AIM: To provide hepatic protection through administration of doxorubicin before stop-flow chemotherapy (SFC) and to investigate the expression of heat shock protein 72(HSP72) and role of nuclear factor kappa B (NF-kB) in this effect.METHODS: The hepatic preconditioning of doxorubicin was established in a porcine model by injection of doxorubidn(1 mg/kg) before SFC. The experimental animals were randomized into two groups: groups receiving doxorubicin(DOX) and normal saline (NS). Serial serum and tissue samples were taken from both groups to evaluate the protection of doxorubicin. Western blot and immunoprecipitation were applied to detect the expression of HSP72, NF-kB p65 protein, inhibitor kB-α (IkB-α) and phosphorylated IkB-α as well. The expression of tumor necrosis factor α (TNF-α) was estimated by semiquantitative RT-PCR. And the extent of the hepatic injury was estimated with the level of serum aminotransferases.RESULTS: An abundance production of HSP72 in porcine liver was observed after 24 h of intravenous administration of doxorubicin, but without any change in the expression of NF-kB p65 subunit in cytoplasm. NF-kB p65 subunit accumulated in nuclei at the end of SFC and reached its highest level at 30 rain after the restoration of the abdominal circulation and decreased gradually during the 6 h after SFC in NS group, while there was little change in DOX group. There was also a slight decrease of IkB-α at 30 min after the restoration of the abdominal circulation in NS group accompanying with the appearance of phosphorylated IkB-α. The expression of TNF-α was significantly higher in NS group than that in DOX group (average 1.40&#177;0.17 vs 0.62&#177;0.22, P&lt;0.01) at serial time points after SFC. Serum ALT and AST levels of NS group were higher after 24 h than those of DOX group (93.2&#177;7.8 IU/L vs 53.34&#177;13.9 IU/L,217.0&#177;29.4 IU/L vs 155.0&#177;15.6 IU/L for ALT and AST respectively, P&lt;0.05) and alter 48 h than those of DOX group (66.6&#177;18.1 IU/L vs 43.3&#177;16.7 IU/L, 174.4&#177;21.3 IU/Lvs 125.7&#177;10.5 IU/L for ALT and AST respectively, P&lt;0.05).CONCLUSION: Doxorubicin renders the liver to be tolerant to the hepatic influence in SFC in a porcine model through the NF-kB/IkB-α pathway with the expression of HSP72.  相似文献   

13.
AIM: To investigate whether the recombinant adenovirus induces the TNF-alpha-mediated apoptosis in vivo. METHODS: Human hepatocarcinoma cell line (HepG(2)) cells were transfected into BALB/c nude mice, and the tumor growth curve was drawn. We analyzed apoptosis in HepG(2) cells by TUNEL, HE staining and electron microscopy. RESULTS: AdIkappaBalphaM was expressed stably and efficiently in HepG(2) and could not be degraded by induction of TNF-alpha. Tumor growth in mice could be reduced remarkably if treated by AdIkappaBalphaM plus TNF-alpha. There was apoptosis of > 70% of cells treated with AdIkappaBalphaM plus TNF-alpha and about 50% of cells treated with AdIkappaBalphaM. In contrast, there was few cell apoptosis in HepG(2) cells treated with phosphate buffered saline and AdIkappaBalpha. HepG(2) cells in mice also exhibited a high level of apoptosis after in vivo injection with AdIkappaBalphaM. The tumor growth curve indicated the tumor transfected with AdIkappaBalphaM could be restrained. CONCLUSION: AdIkappaBalphaM gene therapy greatly enhances apoptosis due to inhibition of an NF-kappaB-mediated antiapoptosis signaling pathway.  相似文献   

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目的探讨PrP105-132作用下体外小胶质细胞分泌IL-8及可能产生途径。方法体外培养大鼠神经胶质细胞,用PrP105-132干预小胶质细胞,并阻断NF-κB途径,ELISA法检测细胞上清液中IL-8含量,RT-PCR法检测细胞NF-κB mRNA水平。结果朊蛋白肽段干预后小胶质细胞活化,胞体增大,细胞突起变短、消失,呈圆状、杆状、阿米巴状。同时细胞上清液中IL-8分泌量增多(P<0.01),阻断NF-κB途径后IL-8分泌量显著降低(P<0.01)。结论PrP能够诱导体外小胶质细胞分泌IL-8,IL-8产生主要依赖于NF-κB途径。  相似文献   

16.
NF-kappaB inducing kinase (NIK) is required for osteoclastogenesis in response to pathologic stimuli, and its loss leads to functional blockade of both alternative and classical NF-kappaB caused by cytoplasmic retention by p100. We now show that deletion of p100 restores the capacity of NIK-deficient osteoclast (OC) precursors to differentiate and normalizes RelB and p65 signaling. Differentiation of NIK-/- precursors is also restored by overexpression of RelB, but not p65. Additionally, RelB-/- precursors fail to form OCs in culture, and this defect is rescued by re-expression of RelB, but not by overexpression of p65. To further support the role of RelB in OCs, we challenged RelB-/- mice with TNF-alpha in vivo and found a diminished osteoclastogenic response. We then examined tumor-induced osteolysis in both RelB-/- and NIK-/- mice by using the B16 melanoma model. Growth of tumor cells in the bone marrow was similar to WT controls, but the absence of either RelB or NIK completely blocked the tumor-induced loss of trabecular bone. Thus, the alternative NF-kappaB pathway, culminating in activation of RelB, has a key and specific role in the differentiation of OCs that cannot be compensated for by p65.  相似文献   

17.
Intestinal IgA+ B cells are generated from IgM+ B cells by in situ class switching in two separate gut microenvironments: organized follicular structures and lamina propria (LP). However, the origin of IgM+ B cells in the gut LP is unknown. Transfer experiments to reconstitute IgM+ B cells and IgA plasma cells in LP of aly/aly mice, which are defective in all organized follicular structures because of an NF-kappaB-inducing kinase (NIK) mutation, revealed that naive B cells can directly migrate to the LP. This migration requires NIK-dependent activation of gut stromal cells. By contrast, the entry of gut-primed IgM+ B cells to the LP is independent of stromal cells with functional NIK. Our results indicate that naive B cells directly migrate to the LP by a distinct pathway from gut-primed B cells.  相似文献   

18.
AIM: To clarify the mechanism underlying the anti-diabetic activities of cortex cinnamomi extract (CCE). METHODS: To induce in vivo diabetes, mice were injected with streptozotocin (STZ) via a tail vein (100 mg STZ/kg body weight). To determine the effects of CCE, mice were administered CCE twice daily for 7 d by oral gavage starting 1 wk before the STZ injection. Blood glucose and plasma insulin concentration were measured as an index of diabetes. Also, to induce cytotoxicity of RINm5F cells, we treated with cytokines (IL-1beta (2.0 ng/mL) and IFN-gamma (100 U/mL)). Cell viability and nitric oxide production were measured colorimetrically. Inducible nitric oxide synthase (iNOS) mRNA and protein expression were determined by RT-PCR and Western blotting, respectively. The activation of NF-kappaB was assayed by using gel mobility shift assays of nuclear extracts. RESULTS: Treatment of mice with STZ resulted in hyperglycemia and hypoinsulinemia, which was further evidenced by immunohistochemical staining of islets. However, the diabetogenic effects of STZ were completely prevented when mice were pretreated with CCE. The inhibitory effect of CCE on STZ-induced hyperglycemia was mediated through the suppression of iNOS expression. In rat insulinoma RINm5F cells, CCE completely protected against interleukin-1beta and interferon-gamma-mediated cytotoxicity. Moreover, RINm5F cells incubated with CCE showed significant reductions in interleukin-1beta and interferon-gamma-induced nitric oxide production and in iNOS mRNA and protein expression, and these findings correlated well with in vivo observations. CONCLUSION: The molecular mechanism by which CCE inhibits iNOS gene expression appears to involve the inhibition of NF-kappaB activation. These results reveal the possible therapeutic value of CCE for the prevention of diabetes mellitus progression.  相似文献   

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