I-Chin Wu

Bio: I-Chin Wu is an academic researcher from National Cheng Kung University. The author has contributed to research in topics: Hepatitis B virus & HBeAg. The author has an hindex of 13, co-authored 32 publications receiving 437 citations.

Very low-density lipoprotein/lipo-viro particles reverse lipoprotein lipase-mediated inhibition of hepatitis C virus infection via apolipoprotein C-III

Abstract: Objective Circulating hepatitis C virus (HCV) virions are associated with triglyceride-rich lipoproteins, including very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL), designated as lipo-viro-particles (LVPs). Previous studies showed that lipoprotein lipase (LPL), a key enzyme for hydrolysing the triglyceride in VLDL to finally become LDL, may suppress HCV infection. This investigation considers the regulation of LPL by lipoproteins and LVPs, and their roles in the LPL-mediated anti-HCV function. Design The lipoproteins were fractionated from normolipidemic blood samples using iodixanol gradients. Subsequent immunoglobulin-affinity purification from the canonical VLDL and LDL yielded the corresponding VLDL-LVP and LDL-LVP. Apolipoprotein (apo) Cs, LPL activity and HCV infection were quantified. Results A higher triglyceride/cholesterol ratio of LDL was found more in HCV-infected donors than in healthy volunteers, and the triglyceride/cholesterol ratio of LDL-LVP was much increased, suggesting that the LPL hydrolysis of triglyceride may be impaired. VLDL, VLDL-LVP, LDL-LVP, but not LDL, suppressed LPL lipolytic activity, which was restored by antibodies that recognised apoC-III/-IV and correlated with the steadily abundant apoC-III/-IV quantities in those particles. In a cell-based system, treatment with VLDL and LVPs reversed the LPL-mediated inhibition of HCV infection in apoC-III/-IV-dependent manners. A multivariate logistic regression revealed that plasma HCV viral loads correlated negatively with LPL lipolytic activity, but positively with the apoC-III content of VLDL. Additionally, apoC-III in VLDL was associated with a higher proportion of HCV-RNA than was IgG. Conclusion This study reveals that LPL is an anti-HCV factor, and that apoC-III in VLDL and LVPs reduces the LPL-mediated inhibition of HCV infection.

Association of intrahepatic cccDNA reduction with the improvement of liver histology in chronic hepatitis B patients receiving oral antiviral agents.

Abstract: Covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) is difficult to eradicate using current antiviral therapy. This study compares cccDNA reduction with relation to liver histology in nucleoside/nucleotide-naive chronic hepatitis B patients receiving oral antiviral monotherapy (n=35), including entecavir (ETV, n=13), adefovir dipivoxil (ADV, n=22) or placebo (n=14). Serum HBV DNA, intrahepatic total HBV DNA and cccDNA are quantified. Histological hepatic examination is performed at baseline and at 48 weeks of treatment. Treatment with ETV or ADV shows significant median reduction in serum HBV DNA (-6.21 and -4.27 log(10) copies/mL) and intrahepatic total HBV DNA (-1.69 and -1.23 log(10) copies/cell). Intrahepatic cccDNA levels are reduced slightly in the ETV and the ADV groups, but do not differ statistically from the placebo group (-0.17 vs. -0.01 vs. 0.02 copies/cell). Only the level of intrahepatic cccDNA correlates with Knodell necroinflammation activity (r=0.527, P<0.001) and Ishak fibrosis severity (r=0.348, P=0.015) before treatment. Multivariate logistic regression analysis indicates that treatment-induced cccDNA reduction is associated with improved necroinflammation (P=0.041) and fibrosis (P=0.026). In conclusion, baseline intrahepatic cccDNA loads correlate with histologic activity. Although one-year ETV or ADV treatment is insufficient for cccDNA eradication, oral antiviral therapies may improve liver histology, probably by suppressing intrahepatic cccDNA.

Aberrant Serum Immunoglobulin G Glycosylation in Chronic Hepatitis B Is Associated With Histological Liver Damage and Reversible by Antiviral Therapy

Abstract: BACKGROUND Aberrant serum immunoglobulin G (IgG) glycosylation and its immunomodulatory effect are rarely addressed in chronic hepatitis B virus (HBV) infection. METHODS Serum IgG-Fc glycosylation profiles in 76 patients with HBV-related liver cirrhosis and 115 patients with chronic hepatitis B (CHB) before and after 48 weeks of anti-HBV nucleos(t)ide analogue treatment were analyzed using high-throughput liquid chromatography-mass spectrometry and were compared to profiles in 108 healthy controls. RESULTS The level of aberrant serum IgG-Fc glycosylation ,: particularly galactose deficiency, was higher in patients with CHB and those with cirrhosis (P < .001 for both) than in healthy controls. IgG galactose deficiency was correlated with the severity of liver necroinflammation and fibrosis in CHB. Multivariate logistic regression analyses showed that the IgG-Fc glycoform with fucosylation and fully galactosylation was an independent factor for a total Knodell necroinflammation score of ≥ 7 (odds ratio, 0.74; 95% confidence interval, .56-.97) and an Ishak fibrosis score of ≥ 3 (odds ratio, 0.69; 95% confidence interval, .49-.97). Administration of antiviral therapy for 48 weeks reversed aberrant IgG-Fc glycosylation in patients with CHB from week 12 onward but did not reverse glycosylation in patients with cirrhosis. Attenuated IgG opsonization in patients with CHB, which was correlated with aberrant Fc-glycosylation, was reversed after treatment as well. CONCLUSIONS Aberrant serum IgG-Fc glycosylation in CHB, which is highly associated with histological liver damage, affects IgG opsonizing activity and can be reversed by antiviral therapy.

Management of hepatitis B: Summary of a clinical research workshop Potential conflict of interest: Dr. Lok is a consultant and received grants from GlaxoSmithKline, Bristol-Myers Squibb, Idenix, Gilead, Roche, and Innogenetics.

Abstract: Chronic hepatitis B is caused by persistent infection with the hepatitis B virus (HBV), a unique DNA virus that replicates through an RNA intermediate produced from a stable covalently closed circular DNA molecule. Viral persistence appears to be due to inadequate innate and adaptive immune responses. Chronic infection has a variable course after several decades resulting in cirrhosis in up to one‐third of patients and liver cancer in a proportion of those with cirrhosis. Sensitive assays for HBV DNA levels in serum have been developed that provide important insights into pathogenesis and natural history. Therapy of hepatitis B is evolving. Peginterferon induces long‐term remissions in disease in one‐third of patients with typical hepatitis B e antigen (HBeAg) positive chronic hepatitis B, but a lesser proportion of those without HBeAg. Several oral nucleoside analogues with activity against HBV have been shown to be effective in suppressing viral levels and improving biochemical and histological features of disease in a high proportion of patients with and without HBeAg, at least in the short term. What is uncertain is which agent or combination of agents is most effective, how long therapy should last, and which criteria should be used to start, continue, switch or stop therapy. Long‐term therapy with nucleoside analogues may be the most appropriate approach to treatment, but the expense and lack of data on long‐term safety and efficacy make recommendations difficult. Clearly, many basic and clinical research challenges remain in defining optimal means of management of chronic hepatitis B. (HEPATOLOGY 2007;45:1056–1075.)

The functional universe of membrane contact sites.

Abstract: Organelles compartmentalize eukaryotic cells, enhancing their ability to respond to environmental and developmental changes. One way in which organelles communicate and integrate their activities is by forming close contacts, often called 'membrane contact sites' (MCSs). Interest in MCSs has grown dramatically in the past decade as it is has become clear that they are ubiquitous and have a much broader range of critical roles in cells than was initially thought. Indeed, functions for MCSs in intracellular signalling (particularly calcium signalling, reactive oxygen species signalling and lipid signalling), autophagy, lipid metabolism, membrane dynamics, cellular stress responses and organelle trafficking and biogenesis have now been reported.