ABSTRACT
Chronic hepatitis B virus (HBV) infection remains a major public health threat worldwide. Current antiviral drugs can effectively inhibit the replication of HBV, but they fail to achieve a complete cure. As the original template for HBV replication, covalently closed circular DNA (cccDNA) is intrinsically stable in vivo and is regarded as the molecular basis for persistent HBV infection and the key target for the cure of HBV infection. Studies on biosynthesis, metabolism, and regulation of HBV cccDNA have been limited by the low copy number of cccDNA within cells and the lack of sensitive and reliable detection methods. Establishment of appropriate research models of cccDNA helps to understand related biological processes. This article reviews the latest research advances in cell models and mouse models of HBV cccDNA, in order to facilitate future studies on HBV virology and development of antiviral drugs against HBV.
ABSTRACT
Objective To investegate the effect of ginsenoside Rg1 on the apoptosis related protein FLICE-inhibitory protein(FLIP),Fas-associated death domain protein (FADD)and Caspase-3 in the subatania nigra(SN)of 1-methyl-4-phenyl-1,2,3,6-tetrahyd-ropyridine (MPTP)-induced mouse models of Parkinson’s disease(PD), and to investigate the role of FADD and FLIP in the pathogenesis of PD and the protective effect of ginsenosides Rg1 on dopaminergic neurons.Methods 45 C57BL/6N mice were randomly divided into control group,model group and ginsenoside Rg1 group (n=15).The mice in model group were injected with MPTP by intraperitoneal,the mice in Rg1 group were injected with ginsenoside Rg1 before injecting MPTP,and the mice in control group were injected with normal saline by intraperitoneal. The behavioral changes of the mice in various groups were observed, and immunohistochemistry and Western blotting methods were used to observe the expressions of tyrosine hydroxylase (TH),FADD,FLIP and Caspase-3 in substantia nigra of the mice.Results Compared with control group,the mice in model group presented with typical symptoms of PD, the TH-positive neurons in the subatania nigra was significantly reduced (P<0.01 ), the number of FADD, FLIP and Caspase-3 positive cells was significantly increased(P<0.01),and the cytoplasm was deeply stained;the protein expression levels of FADD,FLIP and Caspase-3 were significantly increased (P<0.01).Compared with model group,the PD symptoms of the mice in ginsenoside Rg1 group reduced, the number of TH-positive neurons was significantly increased, the number of positive cells of FLIP,FADD and Caspase-3 were significantly reduced(P<0.01),and the cytoplasm was lightly stained;the protein expression levels of FADD, FLIP and Caspase-3 were significantly reduced (P<0.01 ). Nonlinear correlation analysis found that there was a positive relationship between the number of FADD and Caspase-3 positive cells (r=0.791,P<0.05).Conclusion Ginsenoside Rg1 may play a neural protective effect dopaminergic on neurons by modulating the FADD and FLIP expressions in SN of PD model mice.
ABSTRACT
Objective To evaluate expression and significance of TLR4 and NF-κB on inflammatory injure after intracerebral hemorrhage in rats .Methods 60 Sprague Dawley maleness rats were randomly divided into Sham group ,12 h ,24 h ,72 h and 7 d af-ter ICH group(12 s) .The ICH was induced by injection of autologous blood in rats .The behavioral changes were detected by neu-rologic deficit score .The water content of the brain was used to evaluate brain edema changes .Number of TLR4 and NF-κB positive cells by Nissl staining and the expression of protein determined by immunohistochemistry and Western blot .Results After ICH 12 h ,expression of TLR4 and NF-κB positive cells around the hematoma were expressed ,with the extension of the time ,expression was gradually increasing ,and after ICH 72 h the expression of protein were the highest .Cerebral edema and severe neurological damage occurred .Western blot shows the amount of TLR4 expression and NF-κB were in line with the result .Conclusion After in-tracerebral hemorrhage in rat causing inflammatory injure of brain tissue around the hematoma .TLR4 may activate the expression of NF-κB involved in the secondary inflammatory injure after intracerebral hemorrhage in rats .