Liposome-mediated delivery of iminosugars enhances efficacy against dengue virus in vivo.

A key challenge faced by promising antiviral drugs, such as iminosugars, is in vivo delivery to achieve effective levels of drug without toxicity. Four iminosugars, all deoxynojirimycin (DNJ) derivatives-N-butyl DNJ (NB-DNJ), N-nonyl DNJ, N-(9-methoxynonyl) DNJ, and N-(6'-[4″-azido-2″-nitrophenylamino]hexyl)-1-DNJ (NAP-DNJ)-potently inhibited both the percentage of cells infected with dengue virus and release of infectious virus from primary human monocyte-derived macrophages, demonstrating their efficacy in primary cells. In a lethal antibody-dependent enhancement mouse model of dengue pathogenesis, free NB-DNJ significantly enhanced survival and lowered viral load in organs and serum. Liposome-mediated delivery of NB-DNJ, in comparison with free NB-DNJ, resulted in a 3-log(10) reduction in the dose of drug sufficient to enhance animal survival. The optimizing of the effective dose in this way could liberate the therapeutic potential of many cytotoxic antivirals against both dengue virus and a wide array of other viruses.

New approaches for biomarker discovery: the search for liver fibrosis markers in hepatitis C patients.

Despite many shortcomings, liver biopsy is regarded as the gold standard for assessing liver fibrosis. A less invasive and equally or more reliable approach would constitute a major advancement in the field. Proteomics can aid discovery of novel serological markers and these proteins can be measured in patient blood. A major challenge of discovering biomarkers in serum is the presence of highly abundant serum proteins, which restricts the levels of total protein loaded onto gels and limits the detection of low abundance features. To overcome this problem, we used two-dimensional gel electrophoresis (2-DE) over a narrow pH 3-5.6 range since this lies outside the range of highly abundant albumin, transferrin and immunoglobulins. In addition, we used in-solution isoelectric focusing followed by SDS-PAGE to find biomarkers in hepatitis C induced liver cirrhosis. Using the pH 3-5.6 range for 2-DE, we achieved improved representation of low abundance features and enhanced separation. We found in-solution isoelectric focusing to be beneficial for analyzing basic, high molecular weight proteins. Using this method, the beta chains of both complement C3 and C4 were found to decrease in serum from hepatitis C patients with cirrhosis, a change not observed previously by 2-DE. We present two proteomics approaches that can aid in the discovery of clinical biomarkers in various diseases and discuss how these approaches have helped to identify 23 novel biomarkers for hepatic fibrosis.

Discovery of novel biomarker candidates for liver fibrosis in hepatitis C patients: a preliminary study.

BACKGROUND: Liver biopsy is the reference standard for assessing liver fibrosis and no reliable non-invasive diagnostic approach is available to discriminate between the intermediate stages of fibrosis. Therefore suitable serological biomarkers of liver fibrosis are urgently needed. We used proteomics to identify novel fibrosis biomarkers in hepatitis C patients with different degrees of liver fibrosis. METHODOLOGY/PRINCIPAL FINDINGS: Proteins in plasma samples from healthy control individuals and patients with hepatitis C virus (HCV) induced cirrhosis were analysed using a proteomics technique: two dimensional gel electrophoresis (2-DE). This technique separated the proteins in plasma samples of control and cirrhotic patients and by visualizing the separated proteins we were able to identify proteins which were increasing or decreasing in hepatic cirrhosis. Identified markers were validated across all Ishak fibrosis stages and compared to the markers used in FibroTest, Enhanced Liver Fibrosis (ELF) test, Hepascore and FIBROSpect by Western blotting. Forty four candidate biomarkers for hepatic fibrosis were identified of which 20 were novel biomarkers of liver fibrosis. Western blot validation of all candidate markers using plasma samples from patients across all Ishak fibrosis scores showed that the markers which changed with increasing fibrosis most consistently included lipid transfer inhibitor protein, complement C3d, corticosteroid-binding globulin, apolipoprotein J and apolipoprotein L1. These five novel fibrosis markers which are secreted in blood showed a promising consistent change with increasing fibrosis stage when compared to the markers used for the FibroTest, ELF test, Hepascore and FIBROSpect. These markers will be further validated using a large clinical cohort. CONCLUSIONS/SIGNIFICANCE: This study identifies 20 novel fibrosis biomarker candidates. The proteins identified may help to assess hepatic fibrosis and eliminate the need for invasive liver biopsies.