ABSTRACT
Objective:Using the macrophage cell lines RAW264.7 stably expressing Rab5a and its dominant negative mutant Rab5aN133I as models to analyze the effect and the mechanism of Rab 5a,Rab5aN133I on CpG-induced production of pro-inflammatory cytokines and type Ⅰ IFN.Methods: The eukaryotic expression vectors of Rab5a and Rab5aN133I were transfected into RAW264.7 cells by liposome,and screened with G418.The G418-resistant colonies were obtained and amplified.The transformed cell lines were i-dentified by RT-PCR,Real time-PCR and Western blot.The production of cytokines were measured after transformed cell lines of Rab5a and Rab5aN133I was stimulation with CpG for 8 h.Results: Rab5a expression in transfected cells was significantly higher than the control cell group (P<0.05).Overexpression of Rab5a significantly promoted the production of TNF -α,IL1-β(P<0.01) and IFN-β( P<0.05) in CpG stimulated RAW264.7.The production of cytokines was restored in Rab 5aN133I transfected cell line.Conclusion:Rab 5a promotes CpG-induced pro-inflammatory cytokines and typeⅠIFN in macrophages,it may be act as a positive regulator in TLR9 signaling pathway.
ABSTRACT
Objective:To explore the inhibitory effects of seabuckthorn polysaccharide on hepatic oxidative stress in a mice model of acute liver injury induced by intraperitoneal injection of LPS and D -GalN and detect the expression on hepatic BCL-2/Bax and PPAR-γ.Methods: C57BL/6 male mice were randomly divided into six groups:control group ( CTRL), model group ( L/G), dexamethasone positive control group ( DXM ) , low ( SPL ) , medium ( SPM ) and high dose group ( SPH ) of seabuckthorn polysaccharide.Mice in the SPL,SPM and SPH group were gavaged with 50,100 and 200 mg/kg seabuckthorn polysaccharide for 14 days respectively.Acute liver injury model were established by intraperitoneal injection of LPS (10 μg/kg) and D-GalN (700 mg/kg) .Serum and liver samples were collected 4 h after model establishment .Serum levels of ALT and AST and the content of MDA were de-tected.Hepatic expression of SOD 2 BCL-2 and Bax was determined by Western blot and the expression of PPAR-γwas detected by im-munohistochemistry .Results:ALT and AST levels significantly increased in the model group and decreased dose-dependently after pre-treatment with seabuckthorn polysaccharide .The level of MDA in the model group increased significantly as compared with the control group and decreased in seabuckthorn polysaccharide groups ,while the level of SOD 2 decreased in the model group and recovered in sea-buckthorn polysaccharide groups .The expression of Bax decreased after pretreatment with seabuckthorn polysaccharide .There was no obvious effect on BCL-2 expression after sea buckthorn polysaccharide supplementation .The expression of PPAR-γreduced in the sea-buckthorn polysaccharide group as compared with the model group .Conclusion:Seabuckthorn polysaccharide protects against LPS /D-GalN-induced liver injury.The effect is associated with an upregulation of SOD 2 and downregulation of Bax .
ABSTRACT
Objective:To study the protective effects of sea buckthorn polysaccharide extracts on lipopolysaccharide( LPS)/D-galactosa mine ( D-GalN )-induced liver injury in mice and investigate the regulation on hepatic TLR4 and SOCS3 expression.Methods:C57BL/6 male mice were randomly divided into six groups:control group,model group,dexamethasone positive control group, low, medium and high dose group of sea buckthorn polysaccharide.Mice in the sea buckthorn polysaccharides low, medium and high dose group were gavaged with 50, 100 and 200 mg/kg sea buckthorn polysaccharide extracts for 14 days respectively.Acute liver injury model were established by intraperitoneal injection of LPS(10 μg/kg) and D-GalN (700 mg/kg).The mice in the dexamethasone positive control group were intraperitoneally injected with dexamethasone (10 mg/kg) before model estab-lishment.Serum and liver samples were collected after model establishment for 4 h .Serum levels of ALT and AST were detected.Histological changes of liver tissue were observed by HE staining.Hepatic expression of TLR4 and SOCS3 was detected by Western blot.Results:Sea buckthorn polysaccharide significantly inhibited LPS/D-GalN-induced elevation in serum levels of ALT and AST.It also alleviated liver cell injury and inflammatory infiltration.Western blot results showed that sea buckthorn polysaccharide inhibited LPS/D-GalN-induced TLR4 expression.SOCS3 expression was not dramatically influenced by sea buckthorn polysaccharide supplementation.Conclusion:Sea buckthorn polysaccharide protects against LPS/D-GalN-induced liver injury.This protective effects may be achieved by inhibiting the expression of TLR4 but not associated with modulation on SOCS3 expression.