Statistical analysis Data are expressed as median and range unless specified. selleck The difference between two groups was analyzed by Wilcoxon rank sum test and Chi-square test using the SAS version 8.0 software. The relationship between two variables was evaluated using the Spearman rank correlation test. A two-side P value < 0.05 was considered statistically significant. Acknowledgments We thank Medjaden Bioscience Limited for assisting in the preparation of this manuscript. Footnotes Competing Interests: The authors have declared that no competing interests exist. Funding: This work supported by grants from the National Natural Science Foundation of China (No. 30972610), Jilin Province Science and Technology Agency (No.

200705128), the Subject of Chinese Medical Science and Technology Projects in Administration of Chinese Medicine of Jilin Province (08sys-086), the Health Department Research Projects in Jilin Province (2009Z054), the Cutting-edge Science and Interdisciplinary Innovation Projects of Jilin University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Lipids have long been known to play dual roles in biological systems, functioning in structural (in biological membranes) and energy storage (in cellular lipid droplets and plasma lipoproteins) capacities. Research over the past few decades has identified additional functions of lipids related to cellular signaling, microdomain organization, and membrane traffic. There are also strong indications of the important role of lipids in various stages of host-pathogen interactions [1].

Sphingomyelin (SM) is a sphingolipid that interacts with cholesterol and glycosphingolipid during formation of the raft domain, which can be extracted for study as a detergent-resistant membrane (DRM) fraction [2]. Recently, raft domains have drawn attention as potential platforms for signal transduction and pathogen infection processes [3], [4]. For instance, raft domains may serve as sites for hepatitis C virus (HCV) replication [5], [6]. Additionally, in vitro analysis indicates that synthetic SM binds to the Batimastat nonstructural 5B polymerase (RdRp) of HCV [7]. This association allows RdRp to localize to the DRM fraction (known to be the site of HCV replication) and activates RdRp, although the degree of binding and activation differs among HCV genotypes [7], [8]. Indeed, suppression of SM biosynthesis with a serine palmitoyltransferase (SPT) inhibitor disrupts the association between RdRp and SM in the DRM fraction, resulting in the suppression of HCV replication [7], [9]. Multiple reports have indicated that HCV modulates lipid metabolism (e.g., cholesterol and fatty acid biosynthesis) to promote viral replication [10]�C[12].