Jhaveri Ravi, Qiang Guan, Diehl Anna Mae
Division of Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA.
J Infect Dis. 2009 Dec 1;200(11):1781-8. doi: 10.1086/648094.
Hepatitis C virus (HCV) is a major cause of liver disease worldwide, with steatosis, or "fatty liver," being a frequent histologic finding. In previous work, we identified sequence polymorphisms within domain 3 (d3) of genotype 3 HCV core protein that correlated with steatosis and in vitro lipid accumulation. In this study, we investigated the sufficiency of d3 to promote lipid accumulation, the role of HCV genotype in d3 lipid accumulation, and the subcellular distribution of d3.
Stable cell lines expressing green fluorescent protein (GFP) fusions with isolates of HCV genotype 3 core steatosis-associated d3 (d3S), non-steatosis-associated d3 (d3NS), and genotype 1 d3 (d3G1) were analyzed by means of immunofluorescence, oil red O (ORO) staining, and triglyceride quantitation.
Cells that expressed d3S had statistically significantly more ORO than did cells expressing d3NS or d3G1 (P=.02 and <.001, respectively), as well as higher triglyceride levels P =.03 and .003, respectively). Immunofluorescence analysis showed that d3 does not colocalize to lipid droplets but partially colocalizes to the Golgi apparatus.
Our results suggest that HCV core d3 is sufficient to mediate the accumulation of lipid by means of a mechanism that is independent of domains 1 and 2. Our results also suggest that altered lipid trafficking may be involved.
丙型肝炎病毒（HCV）是全球肝脏疾病的主要病因，脂肪变性或“脂肪肝”是常见的组织学表现。在先前的研究中，我们在3型HCV核心蛋白的结构域3（d3）中鉴定出与脂肪变性和体外脂质积累相关的序列多态性。在本研究中，我们调查了d3促进脂质积累的充分性、HCV基因型在d3脂质积累中的作用以及d3的亚细胞分布。
通过免疫荧光、油红O（ORO）染色和甘油三酯定量分析稳定表达绿色荧光蛋白（GFP）与3型HCV核心脂肪变性相关d3（d3S）、非脂肪变性相关d3（d3NS）和1型d3（d3G1）分离株融合蛋白的细胞系。
表达d3S的细胞与表达d3NS或d3G1的细胞相比，ORO含量在统计学上显著更高（分别为P = 0.02和<0.001），甘油三酯水平也更高（分别为P = 0.03和0.003）。免疫荧光分析表明，d3不与脂滴共定位，但部分与高尔基体共定位。
我们的结果表明，HCV核心d3足以通过一种独立于结构域1和2的机制介导脂质积累。我们的结果还表明，脂质转运改变可能参与其中。
