NF-kappaB P65 mRNA Research Articles

Methylprednisolone attenuates lipopolysaccharide-induced Fractalkine expression in kidney of Lupus-prone MRL/lpr mice through the NF-kappaB pathway.

BackgroundFractalkine (FKN) is involved in the occurrence and development of human lupus nephritis. It is known to be upregulated by lipopolysaccharide (LPS) as a stimulus in vivo. MRL/lpr mice have been used as an in vivo model to study lupus nephritis. Methylprednisolone (MP) is used widely in the clinical treatment of progressive glomerular diseases such as lupus nephritis. The aim of this study is to explore the mechanism of LPS induced FKN expression and to determine whether other molecular mechanisms contribute to the signaling pathway of MP action in MRL/lpr mice.MethodsForty-eight female MRL/lpr mice at 12 weeks of age were randomly distributed into six groups. Each group received various treatments for 8 weeks by receiving twice weekly intraperitoneal injections of (1) MP (MP-treated mice), of (2) SC-514 (SC-514-induced mice), of (3) normal saline and a single injection of LPS (LPS-induced mice), of (4) MP and a single injection of LPS (LPS + MP mice), of (5) SC-514 and a single injection of LPS (LPS + SC mice) and of (6) normal saline (control mice). One-way ANOVA was used for data analysis and P value <0.05 was considered statistically significantly.ResultsThe expression of FKN and NF-kappaB p65 mRNA was detected by qPCR. The expression of FKN protein and the activation of NF-kappaB p65 were detected by immunohistochemistry and western blots respectively. The expression of FKN in the kidney of LPS induced mice was significantly increased and this was mediated by increased expression of NF-κB p65 and an increase in NF-kappaB phospho-p65. MP reduced proteinuria and ameliorated the renal damage in MRL/lpr mice. MP as well as the NF-kappaB inhibitor, SC-514, inhibited the LPS-induced increase of expression of FKN and the activation of NF-kappaB.ConclusionsThe results indicate that MP attenuates LPS-induced FKN expression in kidney of MRL/lpr mice through the NF-kappaB pathway.

Suppression of NF‐kappaB p65 expression attenuates delayed xenograft rejection

Delayed xenograft rejection (DXR) involves type II vascular endothelial cell (VEC) activation including upregulation of pro-inflammatory genes, which contributes to infiltration into the graft and a complex process of cytokine production. Approaches to prevent DXR have shown limited success. In this study, we modified heart donors using siRNA in an attempt to attenuate DXR and to improve xenograft survival in the mouse-to-rat heterotopic heart transplant model. siRNA technology was used to inhibit NF-kappaB p65 gene expression in vivo in mice. After the donor was transfected with siRNA, the effects of NF-kappaB siRNA on DXR and expression of NF-kappaB and pro-inflammatory genes were evaluated in a concordant mouse-to-rat cardiac xenograft model. Treatment of NF-kappaB siRNA prolonged median heart graft survival time in the recipient rats from 1.7days in a PBS control group to 5.4days in the NF-kappaB siRNA-treated group (P<0.05). Compared with normal mouse hearts, the NF-kappaB p65 mRNA relative levels following siRNA injection in the donors decreased significantly (approximately 70% reduction) in grafts harvested 12h after transplantation. The mRNA levels of VCAM-1, ICAM-1, and interleukin-1 displayed a similar reduction. Histological evaluation using light and electron microscopy showed that damage of endothelial cells after NF-kappaB siRNA treament occured at a later time. Transfection of NF-kappaB p65 siRNA in donor animals can delay the emergence of DXR. This treatment may be used as part of strategies to minimize the complex and multi-faceted rejection responses in vascularized xenografts.

Effect of pretreatment with puerarin on activation of LPS-induced RAW264.7 cells

To observe the effect of pretreatment with puerarin on activation of LPS -induced RAW264. 7 cells and secretory cytokines, and discuss its anti-inflammatory mechanism. Well-grown RAW264. 7 cells in the exponential phase were collected and randomly divided them into the blank control group, the LPS group and the puerarin pretreatment + LPS group. The cellular toxic effect of puerarin on RAW264. 7 cells was examined by CCK-8 assay, cell morphology was detected by Giemsa stain method, the changes in TNF-alpha and MIP-2 were tested by ELISA, and the expression of NF-kappaB p65 mRNA were determined by qRT-PCR. When puerarin was cultured with 1 mg x L(-1) LPS at a concentration of lower than 400 micromol x L(-1), it had not showed the cellular toxic effect (P < 0.05). Compared with the control group, the LPS group could significantly change the morphology of RAW264. 7 cells (increase in cell body, irregular shape, with a large number of pseudopodia extending). After intervention, the puerarin 100 micromol x L(-1) group could significantly inhibit LPS-induced cell morphological changes, while the puerarin 200 micromol x L(-1) and 400 micromol x L(-1) puerarin groups showed more notable inhibitory effects. However, there was no obvious difference between the two groups. The pretreatment with puerarin could inhibit the expression of TNF-alpha and MIP-2 in cell supernatant and NF-kappaB p65 mRNA in cells (P < 0.05). With increase in the puerarin concentration, its inhibitory effect gradually grew (P < 0.05), but did not reach the level of the blank control group. As a safe and effective natural anti-inflammatory drug, puerarin can significantly reduce the expression of inflammatory cytokines (TNF-alpha, MIP-2). Its mechanism may be related to the reduction of NF-kappaB p65 mRNA expression.

NF-kappaB p65 modulates the telomerase reverse transcriptase in the HepG 2 hepatoma cell line

Nuclear factor-kappa B (NF-kappaB) regulates the expression of various genes, several genes involved in inflammation and tumorigenesis, including those of the liver. A role for NF-kappaB has been implicated in the pathogenesis of hepatocellular carcinoma. This transcription factor can regulate hTERT gene transcription. Expression of hTERT was found to be at high levels in hepatocellular carcinoma. However, positive effects of NF-kappaB on hTERT protein synthesis in HepG 2 cells are unknown. In this study, we show that LPS (specific binding to TLR4 to activate NF-kappaB) was positive for NF-kappaB p65 mRNA expression and activation, and also up-regulated hTERT mRNA and protein expressions at 36 h in a dose-dependent manner. In contrast, MG-132 (blocking the activity of 26S proteasome and thereby preventing nuclear translocation of NF-kappaB) significantly inhibited activation of NF-kappaB and mRNA expression. And also reduced the expression of hTERT at both mRNA and protein levels at 36 h in a dose-dependent manner. Furthermore, dexamethasone inhibited LPS-induced activation of NF-kappaB and expression of the hTERT in HepG 2 cells. These findings suggest that NF-kappaB may modulate hTERT mRNA level, importantly, in protein level in HepG 2 cells and dexamethasone inhibits LPS-induced hTERT via blocking NF-kappaB.

Effect of ulinastatin on the expression of heat shock protein 70 and NF-kappaB in lung tissue in rats with paraquat poisoned

To observe the expression levels of heat shock protein 70 (hsp70) and NF-kappaB p65 mRNA in lung tissue of acute paraquat (PQ) poisoning rats, and intervention effects of ulinastatin (UTI). Seventy-two Sprague-Dawley (SD) rats were randomly divided into three groups: PQ poisoning group, UTI group and control group. The rats were exposed intragastrically to PQ at the dose of 80 mg/kg to establish a model of the rat acute lung injury. The UTI group was intervened by peritoneal injection with 10000 U/kg UTI in 30 minutes. On the 12, 24, 48, 72 h after exposure, myeloperoxidase (MPO) activity in lung tissue were detected. The expression of the NF-kappaB p65 mRNA and hsp70 mRNA in lung tissue was detected by the reverse transcription-PCR (RT-PCR). The lung pathological changes of rats were observed. The degree of lung injury in PQ group and UTI group was higher than that in control group. But in UTI group the degree of lung injury was lower than PQ group. MPO activity in the lung tissues in PQ group was (31.72 +/- 6.42), (56.23 +/- 8.63), (87.21 +/- 10.02) and (107.21 +/- 13.52) micro/g in 12, 24, 48 and 72 h, respectively which was significantly higher than that [(11.38 +/- 1.25) micro/g] in control group (P < 0.01). MPO activity in the lung tissues in UTI group was (15.65 +/- 3.21), (35.98 +/- 5.74), (59.33 +/- 9.65) and (71.25 +/- 10.58) micro/g in 12, 24, 48 and 72 h, respectively which was significantly lower than those in PQ group (P < 0.01). The expression levels of NF-kappaB p65 mRNA of lung tissues in UTI group in 12, 24, 48 and 72 h were 0.3288 +/- 0.0147, 0.5337 +/- 0.0328, 0.7357 +/- 0.0424 and 0.7547 +/- 0.0905, respectively, which were significantly lower that those (0.4185 +/- 0.0294, 0.8532 +/- 0.0841, 0.9554 +/- 0.0975 and 1.0094 +/- 0.0703) in PQ group (P < 0.01). hsp70 mRNA expression levels in 12, 24, 48 and 72 h of the UTI group were 0.5193 +/- 0.0254, 0.8289 +/- 0.0606, 0.7566 +/- 0.0277 and 0.4873 +/- 0.0105, respectively, which were significantly higher than those (0.3897 +/- 0.0125, 0.5904 +/- 0.0186, 0.4007 +/- 0.0237 and 0.2293 +/- 0.0137) in PQ group (P < 0.01). The expression levels of hsp70 mRNA and NF-kappaB p65 mRNA of rats after intoxication increased significantly. UTI can protect the lung tissues by elevating the expression of hsp70 and reducing the expression of NF-kappaB in the lung tissues of rats with acute paraquat poisoning.

Effect of retroviral vector mediating RNA interference on the release of tumor necrosis factor-alpha in lipopolysaccharide-stimulating macrophage

To explore the effect of small interfering RNA (siRNA) targeting NF-kappaB signal pathway on the expression level of tumor necrosis factor alpha (TNF-alpha) released by lipopolysaccharides (LPS)-stimulating-macrophages. Human monocytic THP-1 cell was induced by phorbol myristate acetate (PMA) and transformed into macrophage. Two groups of macrophage were infected by siRNA retroviral expression vector specific to NF-kappaB functional subunit P65 (siRNA group) and Scramble control vector (Scramble control group) constructed by molecular cloning technology. Lipopolysaccharide (50 microg/ml) was used to treat the macrophages continuously. RT-PCR was performed to detect the expression level of NF-kappaB P65 mRNA and TNF-alpha mRNA at different time-points of LPS stimulation. Western blotting was used to analyze the protein level of NF-kappaB P65. Enzyme-linked immunosorbent assay was applied to analyze the expression level of TNF-alpha released by LPS-stimulated macrophages. At Hours 12 and 24 after LPS stimulation, the expression level of NF-kappaB P65 mRNA in siRNA group (0.97 +/- 0.02, 0.89 +/- 0.01) was significantly less than that in Scramble control group (1.01 +/- 0.03, 0.97 +/- 0.01, both P < 0.05). At Hours 24 and 72 after LPS stimulation, the expression level of NF-kappaB P65 protein in siRNA group (0.95 +/- 0.04, 0.94 +/- 0.01) was obviously less than that in Scramble control group (1.07 +/- 0.06, 1.03 +/- 0.05, both P < 0.05). At Hours 4, 8, 12 and 24 after LPS stimulation, TNF-alpha mRNA released by siRNA group macrophages was far less than that by Scramble control group macrophages (0.92 +/- 0.02 vs 0.98 +/- 0.01, 0.86 +/- 0.02 vs 1.00 +/- 0.01, 0.79 +/- 0.03 vs 1.01 +/- 0.01, 0.78 +/- 0.03 vs 1.02 +/- 0.01, all P < 0.05). At Hours 2, 4, 8, 24, 36, 48, 54 and 72 after LPS stimulation, the TNF-alpha content in culture medium supernatant in siRNA group macrophage was less than that in scramble control group (P < 0.05). NF-kappaB P65 siRNA inhibits the functional activity of NF-kappaB signal pathway in PMA-induced macrophage. Then it blocks the activation of macrophage and the excessive release of TNF-alpha due to endotoxin stimulation. The RNA interference technology may be applied to prevent and treat excessive inflammatory reaction in acute lung injury.

Effect of Dureping injection on TIR signal pathway on Ana-1 cells

To investigate the influence of Dureping injection to the murinal celiac macrophage Ana-1 on TIR signal pathway. Ana-1 cell line was infected by influenza virus FM1 strain and treated with the Dureping injection in different concentrations (10.1 mg x L(-1) group) for 12 h and 24 h. Then we collected the cells, extracted mRNA and measured the expressions of TLR7, MyD88, IRAK4, TRAF6 and NF-kappaB p65 respectively by RT-PCR. Dureping injection down-regulated the expression of TLR7, MyD88, IRAK4, TRAF6 and NF-kappaB p65 mRNA in Ana-1 cell line infected by influenza virus, in a dose-dependent manner significantly. Dureping injection has an obvious effect against influenza virus FM1 strain by regulating the TIR signal pathway.

Association study between polymorphisms in selenoprotein genes and susceptibility to Kashin-Beck disease

Kashin-Beck disease (KBD) is a disabling osteoarthropathy involving growth cartilage endemic to selenium (Se)-deficient regions in China. Associations between genetic variation in selenoprotein genes and susceptibility to many diseases have recently been investigated but few studies have been performed on KBD. We found four genetic polymorphisms in selenoprotein genes and assessed their association with increased susceptibility to KBD. Four polymorphisms including GPX1 (rs1050450), TrxR2 (rs5748469), SEPP1 (rs7579) and DIO2 (rs225014) were analyzed for 161 KBD patients and 312 controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or tetra-primer amplification refractory mutation system PCR (Tetra-primer ARMS PCR). Glutathione peroxidase (GPX) activity in whole blood was measured using a GPX assay kit. The mRNA expression of GPX1, nuclear factor-kappaB (NF-kappaB) p65 and p53 in both whole blood and articular cartilage tissue were detected using Real-Time PCR. The genotypic and allelic frequency of GPX1 Pro198Leu was significantly different between KBD patients and controls (P=0.013, P=0.037). A significant increased KBD risk was observed in individuals with Pro/Leu or Leu/Leu (odds ratio=1.781; 95% confidence interval: 1.127-2.814) compared with Pro/Pro. No association was observed between the other three single nucleotide polymorphisms (SNPs) and KBD risk. In addition, GPX enzyme activity in whole blood was lower in the KBD group (P<0.01), and the GPX activity in whole blood decreased significantly in a subgroup of individuals representing Pro/Leu and Leu/Leu compared to Pro/Pro (P<0.01). In whole blood and articular cartilage tissue samples of KBD patients, GPX1 and NF-kappaB p65 mRNA levels were lower (P<0.01) while p53 levels were higher (P<0.001). GPX1 Pro198Leu is a potential genetic risk factor in the development of KBD and the GPX1 Leu allele is significantly associated with higher KBD risk among the Chinese Han population and with lower GPX enzyme activity. The expression of apoptosis related molecules in KBD patients significantly differs from controls.

TLR4 signaling induced TLR2 expression in the process of mimic cerebral ischemia/reperfusion in vitro

Both TLR4 and TLR2 participated in the mediation of the inflammatory injury in the process of partial cerebral ischemia/reperfusion. However, it still remains unclear whether a crosstalk exists between TLR2 and TLR4 in ischemic cerebral damage. In the present study, we investigated the effect of TLR4 signaling on TLR2 expression during mimic cerebral I/R in vitro. BV-2 cells were cultured and treated with ischemia/reperfusion, then transfected with the plasmid pEGFP-H1/TLR4-siRNA, the plasmid pEGFP-H1/control sequence-siRNA and the blank plasmid, respectively. Interestingly, the expression of TLR2 and TLR4 mRNA and protein, NF-kappaB p65 mRNA and supernatant TNF-alpha level were significantly higher in ischemia/reperfusion treated cells than those lack of ischemia/reperfusion treatment, and as compared with those in ischemia/reperfusion treated cells without transfection, no significant differences about the above mentioned gene and protein expression were found in the blank plasmid tranfected cells and the plasmid pEGFP-H1/control sequence-siRNA transfected cells respectively, while the expression levels in the plasmid pEGFP-H1/TLR4-siRNA transfected cells were significantly lower. Additionally, in order to determine the effects of pyrrolidinediethyldithiocarbamate (PDTC), an NF-kappaB inhibitor, on the TLR4-induced TLR2 expression in BV-2 cells treated with ischemia/reperfusion, it was found that TLR4 and TLR2 mRNA expressions in PDTC pretreated cells were significantly lower in comparison with normal saline pretreated cells and non-pretreated cells. The data suggested that TLR2 activation, signaled by TLR4 and regulated by NF-kappaB, might be directly involved play an important role in ischemia/reperfusion induced brain damage.

Study of the role of nuclear factor-kappa B in preterm birth with subclinical chorioamnionitis

To investigate the role of nuclear factor-kappa B (NF-kappaB) in preterm birth with subclinical chorioamnionitis. From October 2005 to October 2006, 111 cases including 36 cases of preterm birth in labor, 37 cases of full term gravida with spontaneous labor and 38 cases of full term gravida without threatened labor in the Hunan Province People's Hospital, third Xiangya Hospital of Central South University and Changsha Maternal and Child Care Service Center were enrolled in the study. After delivery, by pathology results of fetal membrane they were divided into two groups: subclinical chorioamnionitis group (subclinical infectious group) and non-infectious group. Immunohistochemical staining and RT-PCR were used to observe the change of the p65 subunit of NF-kappaB family in maternal blood and fetal membrane in subclinical infectious group and non-infectious group. (1) The incidence of subclinical chorioamnionitis: there were 24 cases of subclinical chorioamnionitis in the 36 cases of preterm birth in labor (67%), 7 cases in the 37 cases of full term gravida with spontaneous labor group (19%) and 3 cases in the 38 cases of full term gravida without threatened labor group (8%). There was a significant difference among the three groups (P < 0.01). In the totally 111 cases, 34 cases were classified as subclinical infectious group and 77 cases as non-infectious group. (2) In fetal membrane, the median of the average staining intensity of NF-kappaB p65 protein was higher in the subclinical chorioamnionitis group (8.0) than those in non-infectious group (4.0). Similarly, the average staining intensity of NF-kappaB p65 mRNA was higher in the subclinical infectious group (47.5 +/- 17.2) than those in non-infectious group (31.3 +/- 13.6). There was a significant difference between the two groups (P < 0.01). (3) In maternal blood, the expression of NF-kappaB p65 protein and mRNA was higher in subclinical chorioamnionitis group(8.0 and 42.6)than those in non-infectious group(4.0 and 23.6).There was a significant difference between the two groups (P < 0.01). (4) The concentration of NF-kappaB p65 protein in fetal membrane was positively correlated with that of maternal blood (r = 0.581, P < 0.01) and the concentration of NF-kappaB p65 mRNA in fetal membrane was positively correlated with that of maternal blood (r = 0.571, P < 0.01). The expression of NF-kappaB in maternal blood and fetal membrane in preterm birth with subclinical chorioamnionitis is higher and the two are correlated with each other. NF-kappaB p65 could be an accurate biochemical marker in predicting subclinical chorioamnionitis in preterm birth. NF-kappaB p65 plays an important role in the pathogenesis of subclinical chorioamnionitis in preterm birth.

Effect of BN52021 on NFκ-Bp65 expression in pancreatic tissues of rats with severe acute pancreatitis

To investigate dynamic changes and significance of expression of NF-kappaBp65 in pancreatic tissues of rats with severe acute pancreatitis (SAP), as well as BN52021 effects. Wistar male rats were randomly divided into negative control group (NC group, n=60), SAP-model group (SAP group, n=60), and BN52021-treated group (BN group, n=60), and each of the above groups was respectively divided into 6 subgroups at different time points after operation (1 h, 2 h, 3 h, 6 h, 12 h, and 24 h) (n=10). By RT-PCR and Western blot, NF-kappaBp65 mRNA and its protein expression in pancreatic tissues of rats were detected respectively. The expression of NF-kappaBp65 mRNA dynamically changed in both SAP groups and BN groups. The mRNA level was higher in SAP groups than NC groups at 2 h, 3 h, 12 h, and 24 h after operation (P<0.05), higher in BN groups than NC groups at all time points (P<0.05), and higher in BN groups than SAP group at 1 h (P<0.05). The NF-kappaBp65 protein level was higher in SAP groups than NC groups at 1 h, 3 h, and 6 h (P<0.01), and 2 h, 12 h, and 24 h (P<0.05), higher in BN groups than NC groups at all time points (P<0.05), and lower in BN groups than SAP groups at 1 h, 3 h, and 6 h (P<0.05). The expression of NF-kappaBp65 in pancreatic tissues is dynamically changed and the changes play an important role in pathogenesis of SAP. BN52021 exerts therapeutic effects through reducing the expression level of NF-kappaBp65 protein in the early stage of SAP.

RETRACTED: The anti-inflammatory activity of 1,25-dihydroxyvitamin D3 in macrophages

In a previous study we demonstrated a down-regulatory effect of vitamin D active metabolite (1,25(OH)(2)D(3)) and its vitamin D(2) analog (1,24(OH)(2)D(2)) on TNFalpha expression in macrophages. We also found an inhibitory effect in the physiological concentration (10(-10)M) of 1,25(OH)(2)D(3) which was dose-dependent. This down-regulation, caused by the decrease in NFkappaB activity by 1,25(OH)(2)D(3) and 1,24(OH)(2)D(2), was demonstrated in P388D1 cells transfected with NFkappaB reporter gene (p NFkappaB-Luc) and by EMSA. In our present study we investigated the processes leading to reduced NFkappaB activity on P388D1 cells. A decrease in nuclei NFkappaB-p65 and an increase in cytosolic NFkappaB-p65, were measured, while no changes in total NFkappaB-p65 mRNA and protein levels were observed. Simultaneously, a significant increase in both mRNA and protein levels of the NFkappaB-cytosolic inhibitor, IkappaBalpha, were determined. The half-life of IkappaBalpha-mRNA increased, with a parallel decrease in the phosphorylation of its protein, as the first step of ubiquitinization and degradation. The present results demonstrate that 1,25(OH)(2)D(3) and 1,24(OH)(2)D(2) inhibit TNFalpha expression in macrophages, by increasing IkappaBalpha and decreasing NFkappaB activity. Since NFkappaB is a major transcription factor for TNFalpha and other inflammatory mediators, these findings suggest that 1,25(OH)(2)D(3) and 1,24(OH)(2)D(2) may be used therapeutically as anti-inflammatory agents.

Nuclear factor kappa B in the dorsal raphe of macaques: Anatomical link for steroids, cytokines and serotonin

Nuclear factor kappa B (NFkappaB) is a transcription factor that activates gene expression in response to proinflammatory cytokines, and elevated cytokines are associated with depression, which has a serotonergic component. We questioned (1) whether serotonin neurons contain NFkappaB, (2) whether NFkappaB detection with immunocytochemistry is changed in the dorsal raphe nucleus (DRN) by ovarian hormone treatment and (3) whether ovarian hormones regulate midbrain NFkappaB gene or protein expression. Monkeys were spayed and treated with placebo, estrogen (E), progesterone (P) or E+P for 1 month (n = 4 animals/treatment group), and the midbrain was harvested for immunocytochemistry and stereology. An antibody that detects nuclear location-specific (NLS)-NFkappaB p65 was applied, and the numbers of NLS-NFkappaB-immunopositive cells were counted in 9 sections of the DRN. Additional monkeys were used for Western blot analysis and quantitative reverse transcription-polymerase chain reaction (RT-PCR) for NFkappaB p65. In placebo-treated macaques, neurons were double-immunostained for serotonin and nuclear NFkappaB p65 throughout the DRN. The mean total number of NFkappaB-positive cells equalled 2178 (and standard error of the mean [SEM] 129) in the placebo group, 1631 (SEM 221) in the E-treated group, 2314 (SEM 186) in the P-treated group and 1162 (SEM 100) in the E+P-treated group (analysis of variance p = 0.003). The E-treated and E+P-treated groups had a significantly lower density of cells stained positive for NFkappaB than the placebo or P-treated groups (post hoc). Unmasking of NLS-NFkappaB immunostaining in the DRN revealed dense immunostaining in the cytoplasm of large dorsal raphe neurons. There was no difference between treatment groups in the amount of NFkappaB p65 detected by Western blot or in the relative expression of NFkappaB p65 mRNA with quantitative RT-PCR. These observations are consistent with the notion that gene and protein expression of NFkappaB are constitutive but that ovarian hormones can decrease the nuclear location of NFkappaB in dorsal raphe neurons and, thereby, decrease the ability of NFkappaB to drive gene expression in response to cytokines.

Vitamin D decreases NFκB activity by increasing IκBα levels

In a previous study we demonstrated the inhibitory effect of 1,25-dihydroxyvitamin D (1,25(OH)(2)D(3)) and its less calcaemic analog 1,24(OH)(2)D(2) on the production of tumour necrosis factor alpha (TNFalpha) by human peritoneal macrophages. The aim of the present study is to examine whether this vitamin D inhibition of TNFalpha is mediated by its major transcription factor, nuclear factor-kappaB (NFkappaB). Murine macrophage cells (P388D1) were incubated with 10(-7) M 1,25(OH)(2)D(3) or 1,24(OH)(2)D(2) and then stimulated with lipopolysaccharide. NFkappaB activity was assayed using a reporter gene and by electrophoretic mobility shift assay (EMSA). In addition, we evaluated mRNA and protein levels of NFkappaB-p65 and of IkappaBalpha, a potent NFkappaB inhibitor, and phosphorylated IkappaBalpha. Both 1,25(OH)(2)D(3) and 1,24(OH)(2)D(2) induced a 60% reduction of TNFalpha secretion. By using a reporter gene and EMSA we found that vitamin D markedly reduced NFkappaB activity. 1,25(OH)(2)D(3) or 1,24(OH)(2)D(2) decreased NFkappaB-p65 levels in the nucleus and increased NFkappaB-p65 levels in the cytosol; no changes were observed in the total levels of NFkappaB-p65 protein and mRNA. Concurrently, vitamin D induced a significant increase in mRNA and protein levels of IkappaBalpha (approximately 6.5- and 4.5-fold, respectively). Elevated levels of IkappaBalpha can be explained by the vitamin D-induced prolongation of IkappaBalpha-mRNA half-life from 110 to 190 min and by the decrease in IkappaBalpha phosphorylation. Vitamin D up-regulates IkappaBalpha levels by increasing mRNA stability and decreasing IkappaBalpha phosphorylation. The increase in IkappaBalpha levels reduces nuclear translocation of NFkappaB and thereby downgrades its activity. Since NFkappaB is a major transcription factor of inflammatory mediators, these findings suggest that the less-calcaemic analog, 1,24(OH)(2)D(2) may be effective as an anti-inflammatory therapeutic agent.

Expression and activity of inducible nitric oxide synthase and endothelial nitric oxide synthase correlate with ethanol-induced liver injury

To study the expression and activity of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) in rats with ethanol-induced liver injury and their relation with liver damage, activation of nuclear factor-kappaB (NF-kappaB) and tumor necrosis factor-alpha (TNF-alpha) expression in the liver. Female Sprague-Dawley rats were given fish oil (0.5 mL) along with ethanol or isocaloric dextrose daily via gastrogavage for 4 or 6 wk. Liver injury was assessed using serum alanine aminotransferase (ALT) activity and pathological analysis. Liver malondialdehyde (MDA), nitric oxide contents, iNOS and eNOS activity were determined. NF-kappaB p65ìiNOS, eNOS and TNF-alpha protein or mRNA expression in the liver were detected by immunohistochemistry or reverse transcriptase-polymerase chain reaction (RT-PCR). Chronic ethanol gavage for 4 wk caused steatosis, inflammation and necrosis in the liver, and elevated serum ALT activity. Prolonged ethanol administration (6 wk) enhanced the liver damage. These responses were accompanied with increased lipid peroxidation, NO contents, iNOS activity and reduced eNOS activity. NF-kappaB p65, iNOS and TNF-alpha protein or mRNA expression were markedly induced after chronic ethanol gavage, whereas eNOS mRNA expression remained unchanged. The enhanced iNOS activity and expression were positively correlated with the liver damage, especially the necro-inflammation, activation of NF-kappaB, and TNF-alpha mRNA expression. iNOS expression and activity are induced in the liver after chronic ethanol exposure in rats, which are correlated with the liver damage, especially the necro-inflammation, activation of NF-kappaB and TNF-alpha expression. eNOS activity is reduced, but its mRNA expression is not affected.

Regulation of expression of nuclear factor kappa B RelA in oligodendrocytes

Little is known about the expression of nuclear factor kappa B (NF-kappaB) in oligodendrocytes. We demonstrate that under normal culture conditions only 21% of oligodendrocytes express NF-kappaB p65; exposure to hypoxia increased this to 69%. A similar increase in total p65 was seen with Western blots. Northern blot analysis demonstrated that NF-kappaB p65 mRNA increased during the first few h following hypoxia, suggesting that exposure to hypoxia affects NF-kappaB p65 transcription or p65 mRNA stability. Under normoxic conditions only 2% of the oligodendrocytes exhibited activated NF-kappaB; this was increased to 8% by hypoxia followed by reoxygenation. Despite activation of NF-kappaB, no detectable expression of the pro-inflammatory genes iNOS and ICAM-1 was seen. This is the first demonstration that hypoxia can up-regulate p65.

Heavy metal ion induction of adhesion molecules and cytokines in human endothelial cells: the role of NF-kappaB, I kappaB-alpha and AP-1.

We analyzed the influence of heavy-metal ions on human umbilical vein endothelial cells (HUVEC) in comparison to proinflammatory cytokines (TNF-alpha, IL-1beta) and lipopolysaccharide (LPS). Adhesion molecule and cytokine expressions are upregulated by heavy-metal exposure. Expression of E-selectin on the cell surface was strongly induced by 1-mM concentrations of NiCl2 and CoCl2, whereas ZnCl2 and CrCl3 had no influence. Furthermore, it is shown that NiCl2 induces mRNA expression of E-selectin, intercellular adhesion molecule-1, IL-6 and IL-8 in a 1-mM concentration. The transcription factor NF-kappaB is known to be involved in the regulation of adhesion molecule expression in endothelial cells after activation by proinflammatory cytokines. We demonstrated that treatment of HUVEC with Ni2+ and Co2+ ions induces the translocation of NF-kappaB p65 and also p50 into the nucleus. NF-kappaB binding activity is enhanced under the influence of heavy metals as determined by mobility shift analysis. P65 and p50 are components of the NF-kappaB complexes as confirmed by supershift analysis. We could show that activation at the protein level is accompanied by induction of NF-kappaB p65 mRNA expression. HUVEC also express the NF-kappaB inhibitor I kappaB-alpha (MAD-3). In the early phase of activation by Ni2+ and Co2+ ions, disappearance of I kappaB-alpha in the cytoplasm accompanied p65 translocation, followed by its gradual reappearence. Because I kappaB mRNA could be upregulated by NiCl2 as well as by a mixture of cytokines, we suggest that the replenishment of the inhibitor in the cytoplasm is caused by de novo I kappaB gene expression. In addition to the enhanced DNA-binding activity of NF-kappaB, another transcription factor, AP-1, was also augmented in HUVEC stimulated by NiCl2, CoCl2 or by proinflammatory mediators and the phorbol ester PMA. Fos protein is shown to be a component of the activated AP-1 complex, as determined by supershift analysis, suggesting that it consists of Jun/Fos heterodimers.