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Objective To explore the effects of zinc finger protein A20(A20) on the expression of CD40 and the phosphorylation of IκBαas well as the local inflammatory reaction of abdominal cavity in Sprague Dawley (SD) rats with peritoneal dialysis-related a-cute peritonitis induced by lipopolysaccharide (LPS ) .Methods 24 male SD rats were equally randomized to four groups (n= 6 , each) .Control group:injected with 4 .25% dextrose peritoneal dialysate(PDF) via abdominal cavity (90 mL/kg);LPS group :injec-ted with LPS(1 mg/kg) via abdominal cavity 4 hour later followed by PDF injection ;transfection A20 plasmid group and empty plasmid group:after transfer pGEM-T easy-A20 or pGEM-T easy plasmid via intraperitoneally using an ultrasound-microbubble-mediated system for 3 days ,then injected with LPS and PDF via abdominal cavity .The rats were killed 4 hours after PDF injection . Peritoneum tissue was stained using Masson and HE .Leucocytes count in abdominal dropsy was performed .The proteins expres-sion of A20 ,p-IκBα,IκBα,and CD40 in peritoneum tissue were analyzed by western blot ;the expression of CD40 mRNA in peritone-um tissue were determined by RT-PCR;IL-6 level in abdominal dropsy was determined by ELISA .Results LPS could induce the protein expression of A20 in rats peritoneum tissue .Compared with LPS group and empty plasmid group ,the degree of edema ,in-flammatory cells infiltration ,and the ratio of p-IκBα/IκBα,mRNA and protein expression of CD40 in rats peritoneum as well as leu-cocyte counts and IL-6 level of abdominal dropsy were also significantly decreased in transfection A20 plasmid group(P0 .05) ,but the mRNA and protein expression of CD40 were significantly higher than that of control group (P<0 .05) .Conclusion Over expression of A20 in SD rats peritoneum tissue could down-regulate the inflammatory reaction in peritonitis induced by LPS ,which might be involved in modulating the expression of associated functional protein during LPS signal pathw ay .
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Objective To investigate the effect and mechanism by which PPARγ ligand, rosiglitasone, regulates the expression of CD40 and intercellular adhesion molecule 1 (ICAM-1) in the rat peritoneal mesothelial cells (RPMCs) induced by lipopolysaccharide (LPS). Methods RPMCs were harvested from Sprague-Dawley rat peritoneal cavity and maintained under defined in vitro conditions. The cells were randomly divided into groups as follows: medium, LPS (5 mg/L), LPS (5 mg/L)+BAY11-7085(5 μmol/L, NF-κB inhibitor), rosiglitazone (10 μmol/L or 20 μmol/L, peroxisome proliferator-activated receptor γ activator), LPS (5 mg/L)+rosiglitazone (10 μmol/L)+GW9662 (3 μmol/L, peroxisome proliferator-aetivatcd receptor γ antagonist), and LPS (5 mg/L)+vehicle (DMSO 0.2 ml/L). The expressions of CD40 and ICAM-1 RNA in RPMCs were examined by RT-PCR after 3 hour treatment, and the protein expressions of CD40, ICAM-1, p-NF-κB p65 and p-IκBα were examined by Western blot or immunofluorescence after 24 hour treatment. Results Following treatment with LPS, both the expressions of CD40 and ICAM-1 protein in RPMCs were up-regulated significantly (P<0.05), and the phosphoralation of p65 was increased greatly (1.10±0.17 vs 0.55±0.06, P<0.05). BAY11-7085 (5 μmol/L) significantly decreased the protein expression of p-p65 (0.22±0.11 vs 1.10±0.17, P<0.01), CD40 (0.34±0.02 vs 0.50±0.06, P<0.05) and ICAM-1 (0.35±0.16 vs 0.74±0.03, P<0.05). Pretreated with rosiglitazone for 3 h then added with LPS for 1 h, the levels of p-p65, CD40 and ICAM-1 in RPMCs were significantly decreased compared with those of LPS group (0.77±0.08 vs 0.90±0.10, P<O.01; 0.79±0.16 vs 0.99±0.06, P<0.05; 0.83±0.20 vs 1.22±0.13, P<0.05). However, for the group pretreated with rosiglitazone(10 μmol/L) and GW9662(3 μmol/L) for 3 h then added with LPS, the levels of p-p65 in RPMCs did not change significantly compared with those of rosiglitazone-pretreated group. The expressions of CD40 and ICAM-1 in RPMCs were significantly increased compared with those of rosiglitazone-pretreated group (0.95±0.19 vs 0.79±0.16, and 1.04±0.24 vs 0.83±0.20, P<0.05). Conclusion Rosiglitazone can decrease LPS-induced expression of CD40 and ICAM-1 in RPMCs by inhibition of NF-κB activation, which suggests that rosiglitazone may mediate its antiinflammatory effect through a NF-κB dependent mechanism.
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ated acute peritonitis induced by LPS in rats.
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Objective To investigate the expression of CD40 and intercellular adhesion molecule-1 (ICAM-1) treated with lipopolysaccharide (LPS) in rat peritoneal mesothelial cells(RPMC) and the role of NF-κB signal transduction pathway. Methods RPMCs were harvested from Sprague-Dawley rat peritoneal cavity and maintained under defined in vitro conditions. The cells were exposed respectively to different concentrations of LPS for 12 h or treated with LPS (5 μg/ml) for different time points. To observe the effect of LPS on the expression of CD40 and ICAM-1, the RPMCs were treated with LPS (5 μg/ml) for different time points. To observe the effect of LPS on the expression of NF-κB and p-NF-κB protein, the RPMCs were treated by LPS or pretreated with BAY11-7085 (5 μmol/L or 1 μmol/L ) for 3 h, then treated with LPS for another 3 h, respectively. Expression of CD40 and ICAM-1 mRNA was examined by RT-PCR. Expression of NF-κB and p-NF-κB protein was detected by Western blot. Results Compared with medium control group, stimulation of RPMCs with 1 μg/ml and 5 μg/ml of LPS resulted in a significant increase in the expression of CD40 and ICAM-1 mRNA(P<0.05). 10 μg/ml of LPS had strongest effect on CD40 and ICAM-1 expression compared with that of 1 μg/ml and 5 μg/ml of LPS. Treatment with 5 μg/ml of LPS resulted in time-dependent increase in the gene level of CD40 and ICAM-1, with the peak at 3 h. However, after that time point, the gene level of them was gradually attenuated. Following treatment with LPS (5 μg/ml), the level of p-NF-κB began to increase at 15 min, gradually reached the peak at 1 h, and then decreased. But the level of p-NF-κB at 2 h was still significantly higher than that of medium control. 5 μmol/L of BAY11-7085 decreased significantly the up-regulation of CD40 and ICAM-1 induced by LPS. Conclusion LPS enhanced the expression of CD40 and ICAM-1 on RPMCs in a concentration-dependent and a time-dependent manner. LPS induced expression of CD40 and ICAM-1 depend on the NF-κB signal transduction pathway.
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Objective To explore the effects of peroxisome proliferator-activated receptorγ (PPARγ) agonist rosiglitazone and 15-deoxy-delta-12,14-prostaglandin J2 (15d-PGJ2) on the expression of PPARγ, toll-like receptor 4 (TLR4) and the activation of STAT1 as well as the local inflammation reaction of abdominal cavity in sprague dawley (SD) rats with peritoneal dialysis- related acute peritonitis induced by lipopolysaccharide (LPS). Methods Twenty-four male SD rats were equally randomized to four groups(n=6 each): control group, injected with 4.25% dextrose peritoneal dialysate (PDF) via abdominal cavity(90 ml/kg); LPS group, injected with LPS(1 mg/kg) via abdominal cavity 4 hours later follewed by PDF injection; rosiglitazone plus LPS group (Rosi group), preconditioned with rosiglitazone (20 mg·kg-1·d-1) by intragastric way for 3 days, then injected with LPS and PDF via abdominal cavity; 15d-PGJ2 plus LPS group (15d-PGJ2 group), preconditioned with 15d-PGJ2 (0.3 mg·kg-1·d-1)via abdominal cavity injection for 3 days, then injected with LPS and PDF via abdominal cavity. The rats were killed 4 hours after PDF injection, IL-6 level in abdominal dropsy was determined by ELISA. Peritoneum tissue was stained by Masson. Leucocyte count in abdominal dropsy was performed. The mRNA expression of PPARγ and TLR4 in peritoneum tissue was determined by RT-PCR; the protein expression of PPARγ, TLR4, p-STAT1 and STAT1 in peritoneum tissue was analyzed by Western blot. Results IL-6 level of abdominal dropsy in LPS group [median 268.53 (range 201.87-335.19) ng/L] was significantly higher than that of control group [median 147.62 (range 130.60-164.64) ng/L] (P<0.01). The IL-6 level of abdominal dropsy in Rosi group [median 110.20 (range 77.60-142.80) ng/L] was significantly lower than that of LPS group (P<0.05). Compared to that of control group, the edematous degree of peritoneum in LPS group was significantly severer, meanwhile, mRNA and proteins expression of PPARγ and TLR4 in rat peritoneum were also significantly higher (P<0.05, P<0.01). Compared to that of LPS group, the edematous degree of peritoneum in Rosi group was lighter, the expression of PPARγ and TLR4 mRNA was significantly up-regulated (P<0.05), meanwhile their proteins expression was down-regulated (P<0.05); and in 15d-PGJ2 group, the edematous degree of peritoneum, the expression of PPARγ mRNA and protein was also decreased (P<0.05), but TLR4 mRNA expression was up-regulated (P<0.01), however, its protein expression was down-regulated (P<0.05). There were no significant differences in leucocyte count of abdominal dropsy among the four groups. The p-STAT1 expression in the rats peritoneum induced by LPS was markedly increased by both rosiglitazone and 15d-PGJ2 (P<0.01). Conclusions Both rosiglitazone and 15d-PGJ2 can down-regnlate the inflammatory reaction in rat peritonitis induced by LIPS, which may be involved in modulating the expression of associated functional protein during LPS signal pathway.