Hepatitis C virus infection often is associated with the accumulation of fat in hepatocytes, which shows a connection between the virus and the lipid metabolism of the liver, according to Sarah Hoffman, MD, of the Leibniz Institute for Experimental Virology, Hamburg, Germany, and her colleagues. “Our study provides a detailed analysis of the changes in the lipid composition in HCV-infected cells that revealed dependency on FA [fatty acid] elongation and desaturation for effective viral replication and virion production,” they reported.
Dr. Hoffman and her colleagues assessed lipid composition of infected cells in an in vitro study of cell lines, which were assessed 8-11 days post infection, according to the report published in BBA: Molecular and Cell Biology of Lipids. They determined the abundance of each major lipid class and compared the pattern of HCV-infected cells with that of controls.
The researchers found that HCV caused an accumulation of membrane phosopholipids but not neutral lipids and that cholesterol accumulated in the perinuclear region of HCV-infected cells. In addition, lipid species with longer fatty acyl chains were more abundant in HCV-infected cells and free polyunsaturated fatty acid (PUFA) levels were greatly increased.
In further confirmation of the critical role of lipid metabolism in HCV replication, they found that knockdown of fatty acid elongases and desaturases disrupted HCV replication, while overexpression of these enzymes showed a proviral effect.
“We identified several lipid-remodeling pathways that are required for distinct steps in viral infection. Future studies have to address the molecular function of longer fatty acyl chains in HCV RNA replication and why PUFAs are needed for HCV particle production,” the researchers concluded.
The authors reported government and institutional-only funding and no personal disclosures.
SOURCE: Hoffman S et al. Biochim Biophys Acta. 2018 Jun 6;1863(9):1041-56.