Institute of Biomedical Research, Taihe Hospital, Hubei University of Medicine, Shiyan 442000, Hubei Province, China.
Institute of Wudang Chinese Medicine, Taihe Hospital, Hubei University of Medicine, Shiyan 442000, Hubei Province, China.
World J Gastroenterol. 2017 Sep 14;23(34):6252-6260. doi: 10.3748/wjg.v23.i34.6252.
To investigate the potential effect of curcumin on hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and the underlying mechanism.
A HepG2.2.15 cell line stably transfected with HBV was treated with curcumin, and HBV surface antigen (HBsAg) and e antigen (HBeAg) expression levels were assessed by ELISA. Intracellular HBV DNA replication intermediates and cccDNA were detected by Southern blot and real-time PCR, respectively. The acetylation levels of histones H3 and H4 were measured by Western blot. H3/H4-bound cccDNA was detected by chromatin immunoprecipitation (ChIP) assays. The deacetylase inhibitors trichostatin A and sodium butyrate were used to study the mechanism of action for curcumin. Additionally, short interfering RNAs (siRNAs) targeting HBV were tested along with curcumin.
Curcumin treatment led to time- and dose-dependent reductions in HBsAg and HBeAg expression and significant reductions in intracellular HBV DNA replication intermediates and HBV cccDNA. After treatment with 20 μmol/L curcumin for 2 d, HBsAg and cccDNA levels in HepG2.2.15 cells were reduced by up to 57.7% ( < 0.01) and 75.5% ( < 0.01), respectively, compared with levels in non-treated cells. Meanwhile, time- and dose-dependent reductions in the histone H3 acetylation levels were also detected upon treatment with curcumin, accompanied by reductions in H3- and H4-bound cccDNA. Furthermore, the deacetylase inhibitors trichostatin A and sodium butyrate could block the effects of curcumin. Additionally, transfection of siRNAs targeting HBV enhanced the inhibitory effects of curcumin.
Curcumin inhibits HBV gene replication down-regulation of cccDNA-bound histone acetylation and has the potential to be developed as a cccDNA-targeting antiviral agent for hepatitis B.
研究姜黄素对乙型肝炎病毒（HBV）共价闭合环状 DNA（cccDNA）的潜在作用及其机制。
用姜黄素处理稳定转染 HBV 的 HepG2.2.15 细胞系，通过酶联免疫吸附试验（ELISA）检测 HBV 表面抗原（HBsAg）和 e 抗原（HBeAg）的表达水平。通过 Southern blot 和实时 PCR 分别检测细胞内 HBV DNA 复制中间体和 cccDNA。通过 Western blot 检测组蛋白 H3 和 H4 的乙酰化水平。通过染色质免疫沉淀（ChIP）检测 H3/H4 结合的 cccDNA。用去乙酰化酶抑制剂曲古抑菌素 A 和丁酸钠研究姜黄素的作用机制。同时，用姜黄素和针对 HBV 的短干扰 RNA（siRNA）进行测试。
姜黄素处理导致 HBsAg 和 HBeAg 表达的时间和剂量依赖性降低，以及细胞内 HBV DNA 复制中间体和 HBV cccDNA 的显著减少。用 20 μmol/L 姜黄素处理 2 d 后，与未经处理的细胞相比，HepG2.2.15 细胞中的 HBsAg 和 cccDNA 水平分别降低了 57.7%（<0.01）和 75.5%（<0.01）。同时，用姜黄素处理还检测到组蛋白 H3 乙酰化水平的时间和剂量依赖性降低，同时 H3 和 H4 结合的 cccDNA 减少。此外，去乙酰化酶抑制剂曲古抑菌素 A 和丁酸钠可阻断姜黄素的作用。此外，转染针对 HBV 的 siRNA 可增强姜黄素的抑制作用。
姜黄素抑制 HBV 基因复制，下调 cccDNA 结合组蛋白乙酰化，有可能成为一种针对乙型肝炎的 cccDNA 靶向抗病毒药物。
