Aims: Deguelin, a natural compound derived from Mundulea sericea (Leguminosae) and some other plants exhibits an activity to inhibit autophagy, a cellular machinery required for hepatitis C virus (HCV) replication. This study aimed to illuminate the impact of deguelin on HCV replication and mechanism(s) involved.
Methods: HCV JFH-1-Huh7 infectious system was used for the investigation. Real time RT-PCR, Western blot, fluorescent microscopy assay were used to measure the expression levels of viral or cellular factors. Overexpression and silencing expression techniques were used to determine the role of key cellular factors.
Results: Deguelin treatment of Huh7 cells significantly inhibited HCV JFH-1 replication in a dose- and time-dependent manner. Deguelin treatment suppressed autophagy in Huh7 cells, evidenced by the decrease of LC3B-II levels, the conversion of LC3B-I to LC3B-II, and the formation of GFP-LC3 puncta as well as the increase of p62 level in deguelin-treated cells compared with control cells. HCV infection could induce autophagy which was also suppressed by deguelin treatment. Mechanism research reveals that deguelin inhibited expression of Beclin1, which is a key cellular factor for the initiation of the autophagosome formation in autophagy. Overexpression or silencing expression of Beclin1 in deguelin-treated Huh7 cells could weaken or enhance the inhibitory effect on autophagy by deguelin, respectively, and thus partially recover or further inhibit HCV replication correspondingly.
Conclusions: Deguelin may serve as a novel anti-HCV compound via its inhibitory effect on autophagy, which warrants further investigation as a potential therapeutic agent for HCV infection.
Keywords: Autophagy; Beclin1; Deguelin; Hepatitis C virus.
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