In pursuit of novel therapeutics targeting the hepatitis B virus (HBV) infection, we evaluated a dihydroquinolizinone compound (DHQ-1) that in the nanomolar range reduced the production of virion and surface protein (HBsAg) in tissue culture. This compound also showed broad HBV genotype coverage, but was inactive against a panel of DNA and RNA viruses of other species. Oral administration of DHQ-1 in the AAV-HBV mouse model resulted in a significant reduction of serum HBsAg as soon as 4 days following the commencement of treatment. Reduction of HBV markers in both in vitro and in vivo experiments was related to the reduced amount of viral RNA including pre-genomic RNA (pgRNA) and 2.4/2.1 kb HBsAg mRNA. Nuclear run-on and subcellular fractionation experiments indicated that DHQ-1 mediated HBV RNA reduction was the result of accelerated viral RNA degradation in the nucleus, rather than the consequence of inhibition of transcription initiation. Through mutagenesis of HBsAg gene sequences, we found induction of HBsAg mRNA decay by DHQ-1 required the presence of the HBV posttranscriptional regulatory element (HPRE), with a 109 nucleotides sequence within the central region of the HPRE alpha sub-element being the most critical. Taken together, the current study shows that a small molecule can reduce the overall levels of HBV RNA, especially the HBsAg mRNA, and viral surface proteins. This may shed light on the development of a new class of HBV therapeutics.

为了追求针对乙型肝炎病毒（HBV）感染的新型疗法，我们评估了一种二氢喹啉嗪酮化合物（DHQ-1），该化合物在纳摩尔浓度范围内减少了组织培养物中病毒体和表面蛋白（HBsAg）的产生。该化合物还显示出广泛的HBV基因型覆盖范围，但对其他种类的DNA和RNA病毒无活性。在开始治疗后4天，在AAV-HBV小鼠模型中口服DHQ-1导致血清HBsAg显着降低。HBV标志物的减少在两个体外和体内实验与减少的病毒RNA数量有关，包括前基因组RNA（pgRNA）和2.4 / 2.1 kb HBsAg mRNA。核运行和亚细胞分级分离实验表明，DHQ-1介导的HBV RNA减少是核中病毒RNA加速降解的结果，而不是转录起始受到抑制的结果。通过诱变HBsAg基因序列，我们发现DHQ-1诱导HBsAg mRNA衰减需要存在HBV转录后调控元件（HPRE），其中HPRE alpha子元件中心区域的109个核苷酸序列最为丰富批判的。综上所述，当前的研究表明，一个小分子可以降低HBV RNA的总体水平，尤其是HBsAg mRNA和病毒表面蛋白。