Mechanisms of hepatic fibrogenesis

Histological outcome for chronic hepatitis B patients treated with entecavir vs lamivudine-based therapy

AIM: To compare the histological outcome of chronic hepatitis B (CHB) patients treated with entecavir (ETV) or lamivudine (LAM)-based therapy.

METHODS: We conducted a retrospective analysis of data from 42 CHB patients with advanced fibrosis (baseline Ishak score ≥ 2) or cirrhosis who were treated with ETV or LAM-based therapy in Beilun People’s Hospital, Ningbo between January 2005 and May 2012. The patients enrolled were more than 16 years of age and underwent a minimum of 12 mo of antiviral therapy. We collected data on the baseline characteristics of each patient and obtained paired liver biopsies pre- and post-treatment. The Knodell scoring system and Ishak fibrosis scores were used to evaluate each example. An improvement or worsening of necroinflammation was defined as ≥ 2-point change in the Knodell inflammatory score. The progression or regression of fibrosis was defined as ≥ 1-point change in the Ishak fibrosis score. The continuous variables were compared using t-test or Mann-Whitney test, and the binary variables were compared using χ² test or Fisher’s exact test. The results of paired liver biopsies were compared with a Wilcoxon signed rank test.

RESULTS: Nineteen patients were treated with ETV and 23 patients were treated with LAM therapy for a mean duration of 39 and 42 mo, respectively. After long-term antiviral treatment, 94.74% (18/19) of the patients in the ETV arm and 95.65% (22/23) in the LAM arm achieved an HBV DNA level less than 1000 IU/mL. The majority of the patients (94.74% in the ETV arm and 73.91% in the LAM arm) had normalized ALT levels. The median Knodell necroinflammatory score decreased from 11 to 0 in the patients receiving ETV, and the median Knodell score decreased from 9 to 3 in the patients receiving LAM (P = 0.0002 and < 0.0001, respectively). The median Ishak fibrosis score showed a 1-point reduction in ETV-treated patients and a 2-point reduction in LAM-treated patients (P = 0.0019 and 0.0205, respectively). The patients receiving ETV showed a more significant improvement in necroinflammation than the LAM-treated patients (P = 0.0003). However, there was no significant difference in fibrotic improvement between the two arms. Furthermore, two patients in each arm achieved a fibrosis score of 0 post-treatment, which indicates a full reversion of fibrosis after antiviral therapy.

CONCLUSION: CHB patients with advanced fibrosis or cirrhosis benefit from antiviral treatment. ETV is superior to LAM therapy in improving necroinflammatory but not fibrotic outcome.

Effect of Yinshao powder on expression of transforming growth factor-β1 and β-catenin in hepatic fibrosis in rats

AIM: To investigate the effect of traditional Chinese medicine Yinshao powder on the expression of transforming growth factor-β1 (TGF-β1) and β-catenin in hepatic fibrosis in rats to clarify the molecular mechanism of clearing heat, expelling damp and promoting blood circulation.

METHODS: Sixty adult male Wistar rats were divided randomly into six groups: a normal control group, a model group, low-, medium- and high-dose Yinshao powder groups and a colchicine group. Hepatic fibrosis was induced by giving subcutaneous injection of carbon tetrachloride, a high-fat diet and 30 mL/L alcohol for 16 wk. At the fifth week, Yinshao powder or colchicine was intragastrically administered. After 12 wk of treatment, the rats were sacrificed to measure serum levels of hyaluronidase (HA), type Ⅳ collagen, procollagen type Ⅲ (PCⅢ), and laminin (LN), observe hepatic pathological changes by HE staining and Masson staining, and determine the mRNA and protein expression levels of TGF-β1 and β-catenin by RT-PCR and Western blot.

RESULTS: Compared with the colchicine group and model group, serum levels of HA, type Ⅳ collagen, PCⅢ, and LN declined significantly in the other groups. The degree of hepatic fibrosis in the Yinshao powder groups was less than that in the colchicine group and model group. The mRNA and protein expression levels of TGF-β1 and β-catenin were significantly lower in the Yinshao powder groups than in the model group and colchicine group.

CONCLUSION: Clearing heat, expelling damp and promoting blood circulation with Yinshao powder for intervention of hepatic fibrosis may be via molecular mechanisms associated with inhibiting or down-regulating the expression of TGF-β1 and β-catenin and blocking the activation of TGF-β1 signaling pathway and Wnt/β-catenin signaling pathway.

Relatedness of Helicobacter pylori populations to gastric carcinogenesis

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that infects half of the human population. The infection is associated with chronic inflammation of the gastric mucosa and peptic ulcers. It is also a major risk factor for gastric cancer. Phylogenetic analysis of global strains reveals there are seven populations of H. pylori, including hpAfrica1, hpAfrica2, hpEastAsia, hpEurope, hpNEAfrica, hpAsia2 and hpSahul. These populations are consistent with their geographical origins, and possibly result from geographical separation of the bacterium leading to reduced bacterial recombination in some populations. For each population, H. pylori has evolved to possess genomic contents distinguishable from others. The hpEurope population is distinct in that it has the largest genome of 1.65 mbp on average, and the highest number of coding sequences. This confers its competitive advantage over other populations but at the cost of a lower infection rate. The large genomic size could be a cause of the frequent occurrence of the deletion of the cag pathogenicity island in H. pylori strains from hpEurope. The incidence of gastric cancer varies among different geographical regions. This can be attributed in part to different rates of infection of H. pylori. Recent studies found that different populations of H. pylori vary in their carcinogenic potential and contribute to the variation in incidence of gastric cancer among geographical regions. This could be related to the ancestral origin of H. pylori. Further studies are indicated to investigate the bacterial factors contributing to differential virulence and their influence on the clinical features in infected individuals.