α-Tocopherol suppresses hepatic steatosis by increasing CPT-1 expression in a mouse model of diet-induced nonalcoholic fatty liver disease.

AIM: Antioxidant therapy for with vitamin E appears to be effective for the treatment of nonalcoholic fatty liver disease　(NAFLD). However, the mechanism of action and optimal therapeutic dosage is unclear. The present study was undertaken to examine whether the effects of α-tocopherol (α-Toc) on NAFLD are dose-dependent in a diet-induced obese model. METHODS: Male mice were fed standard chow, high-fat (HF) diet, HF diet with low-dose, or with high dose of α-Toc supplementation. Histological findings, triglyceride content, and the levels of protein expression related to fatty acid synthesis/oxidation such as carnitine palmitoyltransferase I (CPT-1) of liver were evaluated. In addition, 2-tetradecylglycidic acid (TDGA), a CPT-1 inhibitor, was administered to mice fed HF diet with low-dose of α-Toc. Finally, HepG2 cells in fat-loaded environment were treated with 0-50 µM α-Toc. RESULTS: Treatment of low-dose of α-Toc decreased HF-induced hepatic fat accumulation, but this finding was not observed in treatment of high dose of α-Toc. HF-induced reduction of CPT-1 was attenuated with low-dose of α-Toc but not with high dose of α-Toc. TDGA suppressed the improvement of histological findings in liver induced by low-dose of α-Toc treatment. CPT-1 expression in HepG2 cells increased in response to low-dose of α-Toc, but not in high dose. CONCLUSIONS: Dual action of α-Toc on CPT-1 protein levels was observed. The effect of vitamin E on NAFLD may be not be dose-dependent.

Usefulness of semiquantitative PCR-Invader assay for selecting candidates for daclatasvir plus asunaprevir combination therapy among patients with hepatitis C virus genotype 1b.

AIMS: PCR-Invader is a highly sensitive assay for detecting non-structural protein 5A (NS5A) resistance-associated variants (RAVs) of hepatitis C virus (HCV). Here, we validated the accuracy of the semiquantitative PCR-Invader (SQ-PI) assay compared to direct sequencing (DS) for identifying NS5A RAVs, and we evaluated the treatment efficacy of daclatasvir plus asunaprevir (DCV + ASV) for patients judged to be non-positive for NS5A RAVs by SQ-PI. METHODS: Detection rates of NS5A RAVs by SQ-PI and DS were compared for 204 patients with HCV genotype 1b. Patients with non-positive results for NS5A RAVs by SQ-PI were treated by DCV + ASV, and the efficacy of this treatment was examined. RESULTS: All samples judged as negative for NS5A RAVs by SQ-PI were similarly judged by DS. However, 29.7% of samples judged as negative for Y93H by DS were judged as weakly positive or positive by SQ-PI. Among 108 patients who were judged as negative by SQ-PI and treated by DCV + ASV, rates of sustained virologic response at 24 weeks (SVR24) were 96.3% in intention-to-treat analysis and 99.0% in patients who completed treatment. Among patients who were weakly positive for Y93H on SQ-PI, the SVR24 rate was 95.0% (19/20). This rate was 100% (78/78) in patients who were negative for Y93H on SQ-PI and completed treatment. CONCLUSION: Treatment efficacy of DCV + ASV was extremely high among patients who were non-positive for NS5A RAVs on SQ-PI, especially for patients with negative results.

Risk factors for deterioration of long-term liver function after radiofrequency ablation therapy.

AIM: To identify factors that influence long-term liver function following radiofrequency ablation (RFA) in patients with viral hepatitis-related hepatocellular carcinoma. METHODS: A total of 123 patients with hepatitis B virus- or hepatitis C virus-related hepatocellular car-cinoma (HCC) (n = 12 and n = 111, respectively) were enrolled. Cumulative rates of worsening Child-Pugh (CP) scores (defined as a 2-point increase) were examined. RESULTS: CP score worsening was confirmed in 22 patients over a mean follow-up period of 43.8 ± 26.3 mo. Multivariate analysis identified CP class, platelet count, and aspartate aminotransferase levels as signi-ficant predictors of a worsening CP score (P = 0.000, P = 0.011 and P = 0.024, respectively). In contrast, repeated RFA was not identified as a risk factor for liver function deterioration. CONCLUSION: Long-term liver function following RFA was dependent on liver functional reserve, the degree of fibrosis present, and the activity of the hepatitis condition for this cohort. Therefore, in order to maintain liver function for an extended period following RFA, suppression of viral hepatitis activity is important even after the treatment of HCC.

High alanine aminotransferase level as a predictor for the incidence of macrovascular disease in type 2 diabetic patients with fatty liver disease.

PURPOSE: We investigated whether fatty liver (FL) disease in type 2 diabetic mellitus (T2DM) patients affects their incidence of macrovascular disease. In addition, we detected a useful marker for predicting the incidence of macrovascular disease events. METHODS: A total of 458 patients who underwent abdominal ultrasonography (US) between April 2003 and March 2004 in a diabetic clinic were divided into FL (n = 211) and non-FL (NFL; n = 247) groups, and followed by a diabetologist and/or hepatologist for 5 years. RESULTS: No significant difference in the incidence of macrovascular disease, neither cerebrovascular disease nor coronary heart disease, was observed between FL and NFL patients. Interestingly, in FL diabetic patients, only an alanine aminotransferase (ALT) level ≥30 IU/l was significantly associated with the incidence of macrovascular events in univariate (odds ratio [OR], 10.632; 95 % confidence interval [CI], 1.302-86.841; p = 0.0274) and multivariate (OR, 10.134; CI 1.223-83.995; p = 0.0318) analyses. Patients with higher ALT levels had a higher cumulative incidence of macrovascular disease events than did those with lower ALT levels (p = 0.0068). In conclusion, an ALT level ≥30 IU/l is an independent risk indicator of macrovascular disease in diabetic patients with FLD, whereas the presence of FL itself in T2DM patients is not associated with an increased incidence of macrovascular events. CONCLUSIONS: Our findings indicate that therapeutic interventions may be necessary for FL patients with high ALT levels to prevent macrovascular disease.

Intraperitoneal administration attenuates thiazolidinedione-induced hepatic steatosis in KKAy mice with increased hepatic peroxisome proliferator-activated receptor (PPAR)γ mRNA expression.

BACKGROUND: The pathogenesis of thiazolidinediones (TZDs)-induced hepatic steatosis in genetically obese diabetic mice has not been fully clarified. We herein examined the effects of pioglitazone treatment on liver histology. METHODS: To investigate TZDs-induced hepatic steatosis, KKAy mice were treated with pioglitazone orally or by intraperitoneal injection. RESULTS: Orally administered pioglitazone at 15 and/or 50 mg/kg/day worsened the hepatic steatosis in KKAy mice, however, the treatment at 50 mg/kg/day was not worse than that at 15 mg/kg/day. The basal expression of peroxisome proliferator-activated receptor (Ppar)γ mRNA in the liver was upregulated to approximately 10% of that in white adipose tissue in these mice. Although no induction of hepatic Pparg mRNA by pioglitazone treatment was observed, the mRNA expression of the downstream lipogenic enzymes significantly increased. On the other hand, intraperitoneal administration of 15 mg/kg/day did not lead to deterioration of the hepatic steatosis of KKAy mice. Moreover, intraperitoneal administration led to an accompanying shift of fat distribution from intra-abdominal to subcutaneous adipose depots, and further increases in the serum adiponectin levels. In addition, a 5 day treatment without any change in body weight led to an obvious improvement in hepatic steatosis. CONCLUSIONS: Intraperitoneal administration of pioglitazone can act more strongly on intra-abdominal adipose tissues, and attenuates TZDs-induced hepatic steatosis in KKAy mice. The present study suggests that hepatic steatosis due to chronic treatment with TZDs is affected by the balance between endogenous lipogenesis in the liver and the lipid storage in adipose tissues, both occurring through PPARγ.

Involvement of remnant spleen volume on the progression of steatohepatitis in diet-induced obese rats after a splenectomy.

AIM: This study investigated the correlation between remnant spleen volume after splenectomy (SPX) and the degree of hepatic steatosis and/or inflammation. METHODS: Male Sprague-Dawley rats were fed HF food and divided into three groups: sham-operation (Sham) group, a hemisplenectomy (H-SPX) group, and a total-splenectomy (T-SPX) group. Serum was collected and livers removed 12 weeks after surgery. We measured serum lipid markers and evaluated liver changes by comparing the three groups. Additionally, we examined liver changes 24 weeks after SPX. RESULTS: Serum triglyceride and free fatty acid levels after SPX were higher than those of sham controls, and a significant difference was found between T-SPX and the other groups (P < 0.05 for each). Increased intrahepatic fat accumulation was shown in SPX rats along with lower residual spleen volume; this fat accumulation after SPX was accelerated in rats at 24 weeks. Additionally, liver inflammatory changes, including an increase in the Kupffer cell population and pro-inflammatory cytokine production, as well as a high level of oxidative stress, were observed in the liver sections from SPX rats, which correlated significantly with less volume of the residual spleen. Also, an increase in pro-inflammatory cytokine content and a decrease in anti-inflammatory cytokine content were shown in the residual spleen from H-SPX rats, as compared to those of sham controls (P < 0.05 for each). CONCLUSION: These results indicate the importance of preserving splenic tissue. This residual spleen may play an important role in preventing the progression from diet-induced hepatic steatosis to steatohepatitis.