Attenuation of Immune-Mediated Renal Injury by Telmisartan, an Angiotensin Receptor Blocker and a Selective PPAR-γ Activator

Background/Aims: Anti-glomerular basement membrane (GBM) nephritis is characterized by activation of the renin-angiotensin system. This study aimed to determine the question of whether a temporary angiotensin II blockade at the initial stage of anti-GBM nephritis is able to attenuate the disease as well as differences in renoprotection among angiotensin II receptor blockers (ARBs) with distinct peroxisome proliferator-activated receptor (PPAR)-γ-modulating activities. Methods: C57BL/6J mice were immunized with rabbit IgG, followed by intravenous injection of rabbit anti-mouse antibodies. Mice were then treated with telmisartan, losartan, and telmisartan + GW9662 (a PPAR-γ antagonist) for 5 days, or hydralazine for 9 days. On days 8 and 13, mice were sacrificed to obtain tissues for histological analysis. Results: The temporary administration of telmisartan significantly suppressed glomerular damage compared to hydralazine. Losartan showed a similar effect but was less effective. Co-administration of GW9662 attenuated the renoprotective effect of telmisartan, almost to levels observed with losartan. In particular, it limited the decreased infiltration of inflammatory cells and preservation of capillaries in the glomeruli induced by telmisartan. Conclusion: Temporary angiotensin II blockade at the initial stage of anti-GBM disease dramatically inhibited its progression. In addition to a class effect of ARBs, telmisartan modified inflammation and endothelial damage in the kidney through its PPAR-γ-agonistic action

Analysis of 5′ Nontranslated Region of Hepatitis A Viral RNA Genotype I from South Korea: Comparison with Disease Severities

The aim of the study was to analyze genotype I hepatitis A virus (HAV) 5′ nontranslated region (NTR) sequences from a recent outbreak in South Korea and compare them with reported sequences from Japan. We collected a total of 54 acute hepatitis A patients' sera from HAV genotype I [27 severe disease (prothrombin time INR≥1.50) and 27 mild hepatitis (prothrombin time INR <1.00)], performed nested RT-PCR of 5′ NTR of HAV directly sequenced from PCR products (∼300 bp), and compared them with each other. We could detect HAV 5′NTR sequences in 19 of the 54 (35.1%) cases [12 of 27 severe cases (44.4%) and 7 of 27 self-limited cases (25.9%)], all of which were subgenotype IA. Sequence analysis revealed that sequences of severe disease had 93.6%–99.0% homology and of self-limited disease 94.3%–98.6% homology, compared to subgenotype IA HAV GBM wild-type IA sequence. In this study, confirmation of the 5′NTR sequence differences between severe disease and mild disease was not carried out. Comparison with Japanese HAV A10 revealed 222C to G or T substitution in 8/12 cases of severe disease and 222C to G or T and 392G to A substitutions in 5/7 and 4/7 cases of mild disease, respectively, although the nucleotide sequences in this study showed high homology (93.6%–100%). In conclusion, HAV 5′NTR subgenotype IA from Korea had relatively high homology to Japanese sequences previously reported from Japan, and this region would be considered one of the antiviral targets. Further studies will be needed

Characterization of a Specific Region in the Hepatitis B Virus Enhancer I for the Efficient Expression of X Gene in the Hepatic Cell

AbstractHepatitis B virus (HBV) enhancer I has been shown to consist of severalcis-acting sequences for the HBV gene expression efficiently in certain types of cells. Transcriptional regulation of HBV X gene mediated by enhancer I might be one of the mechanisms by which HBV obtains hepatotropism. By mutagenesis analysis of enhancer I function in the enhancer I/X gene promoter complex, we characterized a specific transcriptional regulatory region (designated as a LSR element, nt 989–1030) of enhancer I for the X gene promoter by means of the transient transfection technique using hepatic and nonhepatic cells. Based on the analysis of protein factors interacting with the LSR element, liver-enriched transcriptional factors, HNF3 and HNF4 or retinoid X receptor α (RXRα), are probably implicated in the activity of enhancer I for the efficient expression of X gene through their interaction with the LSR element in the hepatic cell. Furthermore, the isolated LSR element was demonstrated to function alone as a specificcis-acting element and to be able to activate transcription from the X gene promoter efficiently in the hepatic cell in an orientation-independent manner

Analysis of 5′ Nontranslated Region of Hepatitis A Viral RNA Genotype I from South Korea: Comparison with Disease Severities

The aim of the study was to analyze genotype I hepatitis A virus (HAV) 5′ nontranslated region (NTR) sequences from a recent outbreak in South Korea and compare them with reported sequences from Japan. We collected a total of 54 acute hepatitis A patients' sera from HAV genotype I [27 severe disease (prothrombin time INR≥1.50) and 27 mild hepatitis (prothrombin time INR <1.00)], performed nested RT-PCR of 5′ NTR of HAV directly sequenced from PCR products (∼300 bp), and compared them with each other. We could detect HAV 5′NTR sequences in 19 of the 54 (35.1%) cases [12 of 27 severe cases (44.4%) and 7 of 27 self-limited cases (25.9%)], all of which were subgenotype IA. Sequence analysis revealed that sequences of severe disease had 93.6%–99.0% homology and of self-limited disease 94.3%–98.6% homology, compared to subgenotype IA HAV GBM wild-type IA sequence. In this study, confirmation of the 5′NTR sequence differences between severe disease and mild disease was not carried out. Comparison with Japanese HAV A10 revealed 222C to G or T substitution in 8/12 cases of severe disease and 222C to G or T and 392G to A substitutions in 5/7 and 4/7 cases of mild disease, respectively, although the nucleotide sequences in this study showed high homology (93.6%–100%). In conclusion, HAV 5′NTR subgenotype IA from Korea had relatively high homology to Japanese sequences previously reported from Japan, and this region would be considered one of the antiviral targets. Further studies will be needed

Demonstration of intrahepatic accumulated microbubble on ultrasound represents the grade of hepatic fibrosis

OBJECTIVES: To examine the feasibility of perflubutane-based ultrasound for grading hepatic fibrosis. METHODS: This prospective study included 202 subjects; main study (controls:33, F0–1:35, F2:26, F3:23, cirrhosis:29) and subsequent study (controls:16, F0–1:7, F2:20, F3:7, cirrhosis:6). Diagnostic abilities for assessing fibrosis grade were compared between contrast findings and FIB4 (age × AST/[platelet count × ALT(0.5)]). RESULTS: High-power emission produced an intrahepatic band-like structure, and the three-layer appearance was less frequent and monolayer appearance was more frequent in cirrhosis than controls/chronic hepatitis (P < 0.0001). Intensity difference at 15-min phase showed most significant correlation with fibrosis grade (ρ = 0.79, P < 0.0001), and the best areas under the receiver operating characteristic curves are 0.88 for marked fibrosis, 0.95 for advanced fibrosis and 0.97 for cirrhosis, which were significantly higher than those of FIB4, 0.85 for marked fibrosis, 0.89 for advanced fibrosis and 0.90 for cirrhosis. Sensitivity, specificity and efficiency of the intensity difference were 88%, 72% and 81% for marked fibrosis, 85%, 91% and 89% for advanced fibrosis and 97%, 90% and 91% for cirrhosis, respectively. The subsequent study validated the main study results; significant correlation between the intensity difference and the fibrosis grade (ρ = 0.73–0.77, P < 0.0001). CONCLUSIONS: Perflubutane-based ultrasound accurately predicts the grade of hepatic fibrosis. KEY POINTS: • The behaviour of intrahepatic microbubbles depends on the severity of hepatic fibrosis. • Layer enhancement pattern simply represents the degree of chronic liver disease. • Parenchymal intensity change due to high-power emission predicts the hepatic fibrosis grade

Palmitate-induced Regulation of PPARγ via PGC1α: a Mechanism for Lipid Accumulation in the Liver in Non- alcoholic Fatty Liver Disease

Abstract The aim was to examine the effect of free fatty acids on the regulation of PPARγ-PGC1α pathway, and the effect of PPARγ/PGC1α in NAFLD. The mRNA and protein expression of PGC1α and phospho/total PPARγ were examined in Huh7 cells after the palmitate/oleate treatment with/without the transfection with siRNA against PGC1a. The palmitate content, mRNA and protein expression of PGC1α and PPARγ in the liver were examined in the control and NAFLD mice. Palmitate (500 μM), but not oleate, increased protein expression of PGC1α and phospho PPARγ (PGC1α, 1.42-fold, P=0.038; phospho PPARγ, 1.56-fold, P=0.022). The palmitate-induced PPARγ mRNA expression was reduced after the transfection (0.46-fold), and the protein expressions of PGC1α (0.52-fold, P=0.019) and phospho PPARγ (0.43-fold, P=0.011) were suppressed in siRNA-transfected cells. The palmitate (12325.8 ± 1758.9 μg/g vs. 6245.6 ± 1182.7 μg/g, p=0.002), and mRNA expression of PGC1α (11.0 vs. 5.5, p=0.03) and PPARγ (4.3 vs. 2.2, p=0.0001) in the liver were higher in high-triglyceride liver mice (&gt;15.2 mg/g) than in low-triglyceride liver mice (&lt;15.2 mg/g). The protein expressions of both PGC1α and PPARγ were higher in the NAFLD group than in the controls (PGC1α, 1.41-fold, P=0.035; PPARγ, 1.39-fold, P=0.042), and were higher in the high-triglyceride liver group (PGC1α, 1.52-fold, p=0.03; PPARγ, 1.22-fold, p=0.05) than in the low-triglyceride liver group. In conclusion, palmitate appear to up-regulate PPARγ via PGC1α in Huh7 cells, and both PGC1α and PPARγ are up-regulated in the NAFLD mice liver, suggesting an effect on lipid metabolism leading to intrahepatic triglyceride accumulation

Inhibitory effects on HAV IRES-mediated translation and replication by a combination of amantadine and interferon-alpha

Hepatitis A virus (HAV) causes acute hepatitis and sometimes leads to fulminant hepatitis. Amantadine is a tricyclic symmetric amine that inhibits the replication of many DNA and RNA viruses. Amantadine was reported to suppress HAV replication, and the efficacy of amantadine was exhibited in its inhibition of the internal ribosomal entry site (IRES) activities of HAV. Interferon (IFN) also has an antiviral effect through the induction of IFN stimulated genes (ISG) and the degradation of viral RNA. To explore the mechanism of the suppression of HAV replication, we examined the effects of the combination of amantadine and IFN-alpha on HAV IRES-mediated translation, HAV replicon replication in human hepatoma cell lines, and HAV KRM003 genotype IIIB strain replication in African green monkey kidney cell GL37. IFN-alpha seems to have no additive effect on HAV IRES-mediated translation inhibition by amantadine. However, suppressions of HAV replicon and HAV replication were stronger with the combination than with amantadine alone. In conclusion, amantadine, in combination of IFN-alpha, might have a beneficial effect in some patients with acute hepatitis A

Hepatitis B Virus e Antigen Physically Associates With Receptor-Interacting Serine/Threonine Protein Kinase 2 and Regulates IL-6 Gene Expression

We previously reported that hepatitis B virus (HBV) e antigen (HBeAg) inhibits production of interleukin 6 by suppressing NF-κB activation. NF-κB is known to be activated through receptor-interacting serine/threonine protein kinase 2 (RIPK2), and we examined the mechanisms of interleukin 6 regulation by HBeAg. HBeAg inhibits RIPK2 expression and interacts with RIPK2, which may represent 2 mechanisms through which HBeAg blocks nucleotide-binding oligomerization domain-containing protein 1 ligand-induced NF-κB activation in HepG2 cells. Our findings identified novel molecular mechanisms whereby HBeAg modulates intracellular signaling pathways by targeting RIPK2, supporting the concept that HBeAg could impair both innate and adaptive immune responses to promote chronic HBV infectio

Factors Associated with Inadequate Tissue Yield in EUS-FNA for Gastric SMT

Aims. Our aim was to identify the factors that made the specimens inadequate and nondiagnostic in endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsy of suspected submucosal tumors (SMTs). Methods. From August 2001 to October 2009, 47 consecutive patients with subepithelial hypoechoic tumors originating in the fourth sonographic layer of the gastric wall suspected as GIST by standard EUS in Chiba University hospital underwent EUS-FNA for histologic diagnosis. We evaluated patient age, sex, location of lesion, size, pattern of growth in a stomach, and pattern of echography retrospectively. We defined a case of gaining no material or an insufficient material for immunohistological diagnosis as nondiagnostic. Results. The diagnostic yield of EUS-FNA for the diagnosis of gastric SMTs was 74.5%. Multivariate logistic regression analysis identified that age of under 60 years (compared with patients older than 60 years: odds ratio [OR] = 11.91, 95% confidence interval [CI] = 1.761–80.48) and location of SMT at lower third area (compared with upper or middle third area: OR = 10.62, 95% CI = 1.290–87.42) were the predictive factors for inadequate tissue yield in EUS-FNA. Conclusions. The factors associated with inadequate tissue yield in EUS-FNA were younger age and the location of lesion at lower third area in stomach