OBJECTIVETo determine the prevalence of mutations in the non-structural protein 5B (NS5B) of the hepatitis C virus (HCV),which are associated with natural resistance to non-nucleoside and nucleoside polymerase inhibitors (PIs),in treatment-naive hepatitis C patients in south China.

METHODSA nested PCR protocol that amplified three different regions of NS5B was used to detect the naturally occurring drag-resistant substitutions.Direct PCR sequencing was performed to analyze the sequences.

RESULTSNS5B mutations known to confer resistance to nucleoside PIs,such as A15G,S96T and S282T,were mainly detected in HCV genotype 6a (20/88,22.73%).Of the NS5B mutations known to confer resistance to non-nucleoside PIs,C316N and S365A were detected in HCV genotype lb (60/60,100% and 2/60,3.33%, respectively) and I482L and V499A were mainly detected in HCV genotype 2a (9/9,100% and 4/4,100%, respectively) and HCV genotype 6a (9/9,100% and 4/4,100%, respectively).Other NS5B mutations found in the study population included A1 5S,S365F,S365P,S368A and S368L;although none of these has been previously shown to confer resistance to PIs.

CONCLUSIONNaturally occurring dominant PI resistance mutations in NS5B exist in treatment-na(i)ve hepatitis C patients in south China and may be related to the virus genotype.

Antiviral Agents ; pharmacology ; China ; Drug Resistance, Viral ; Genotype ; Hepacivirus ; drug effects ; genetics ; Hepatitis C ; drug therapy ; virology ; Humans ; Mutation ; Viral Nonstructural Proteins ; genetics

Objective : To investigate the effect of hypoxic preconditioning (HPC) on mitochondrial energy metabolism in mouse hippocampal HT22 cells and its possible mechanism. Methods : In this paper, mouse hippocampal nerve cells HT22 were divided into control group, hypoxia group, HPC group, and the levels of adenosine triphosphate (ATP) and reactive oxygen species (ROS) in each group were measured for observing the effect of HPC on cell mitochondrial metabolism. Western blot was used to detect the expression of target of rapamycin ( mTOR), phosphorylated mTOR protein and autophagy substrate P62 protein; cellular immunofluorescence was used to detect phosphorylated mTOR, and LysoTrackerTM probe was used to detect lysosomes. Results : Compared with the control group, the ATP level was significantly decreased and the ROS level was increased in the hypoxia group. Exposed to HPC, the ATP level was increased and the ROS level was decreased. Compared with the control group, the expression of phosphorylated mTOR was down⁃regulated and the expression of autophagy substrate P62 was down⁃regulated in the HPC group. Conclusion HPC may affect the energy metabolism of HT22 cells through the mTOR/autophagy signaling pathway, thereby exerting a protective effect on the HT22 cells.