Hepatitis B Core-Related Antigen to Indicate High Viral Load: Systematic Review and Meta-Analysis of 10,397 Individual Participants.

BACKGROUND & AIMS: To eliminate hepatitis B virus (HBV) infection, scale-up of testing and treatment in resource-limited countries is crucial. However, access to nucleic acid testing to quantify HBV DNA, an essential test to examine treatment eligibility, remains severely limited. We assessed the performance of a novel immunoassay, HBV core-related antigen (HBcrAg), as a low-cost (less than US $15/assay) alternative to nucleic acid testing to indicate clinically important high viremia in chronic HBV patients infected with different genotypes. METHODS: We searched Medline, Embase, Scopus, and Web of Science databases through June 27, 2018. Three reviewers independently selected studies measuring HBV DNA and HBcrAg in the same blood samples. We contacted authors to provide individual participant data (IPD). We randomly allocated each IPD to a derivation or validation cohort. We applied optimal HBcrAg cut-off values derived from the derivation set to the validation set to estimate sensitivity/specificity. RESULTS: Of 74 eligible studies, IPD were obtained successfully for 60 studies (81%). Meta-analysis included 5591 IPD without antiviral therapy and 4806 treated with antivirals. In untreated patients, the pooled area under the receiver operating characteristic curve and optimal cut-off values were as follows: 0.88 (95% CI, 0.83-0.94) and 3.6 log U/mL to diagnose HBV DNA level of 2000 IU/mL or greater; and 0.96 (95% CI, 0.94-0.98) and 5.3 log U/mL for 200,000 IU/mL or greater, respectively. In the validation set, the sensitivity and specificity were 85.2% and 84.7% to diagnose HBV DNA level of 2000 IU/mL or greater, and 91.8% and 90.5% for 200,000 IU/mL or greater, respectively. The performance did not vary by HBV genotypes. In patients treated with anti-HBV therapy the correlation between HBcrAg and HBV DNA was poor. CONCLUSIONS: HBcrAg might be a useful serologic marker to indicate clinically important high viremia in treatment-naïve, HBV-infected patients.

Clinical utility of FibroScan as a non-invasive diagnostic test for primary biliary cholangitis.

BACKGROUND AND AIM: Primary biliary cholangitis (PBC) is a chronic, slowly progressive, autoimmune liver disease. Some PBC patients display disease progression regardless of medical treatment. Therefore, it is important to accurately diagnose the clinical stage of PBC. This study investigated clinical merits of vibration-controlled transient elastography using FibroScan for assessing disease stage in PBC. METHODS: A total of 74 treatment-naïve PBC patients (84% female, median age: 64 years), 69 of whom having undergone histological assessment and five clinically diagnosed as at the cirrhosis stage, were enrolled for clinical comparisons of liver stiffness measurement (LSM) with other established indices. RESULTS: The number of patients with Nakanuma stages 1, 2, 3, and 4 was 18, 33, 17, and 6, respectively. The median LSM values for Nakanuma stages 1, 2, 3, and 4 were 5.05, 5.90, 8.90, and 23.70 kPa, respectively, and correlated significantly with disease progression based on Nakanuma's classification (r = 0.501, P < 0.001). LSM was also significantly related to other non-invasive serological markers (Mac-2 binding protein glycosylation isomer: r = 0.606, FIB-4 index: r = 0.493, and aspartate aminotransferase-to-platelet ratio index: r = 0.577; all P < 0.001). The areas under the receiver operating characteristic curve for diagnosing Nakanuma stage ≥ 2, stage ≥ 3, and stage 4 were 0.744, 0.763, and 0.907, respectively. A combination of LSM ≥ 7.0 kPa and Mac-2 binding protein glycosylation isomer ≥ 1.00 cut-off index could predict late-stage PBC (i.e. moderate to advanced disease progression) with a sensitivity of 0.58, specificity of 0.82, and accuracy of 0.74. CONCLUSIONS: Liver stiffness measurement using FibroScan provided simple, accurate, and non-invasive assessment of disease stage in PBC patients.

Therapeutic Application of Small Extracellular Vesicles (sEVs): Pharmaceutical and Pharmacokinetic Challenges.

Small extracellular vesicles (sEVs), including exosomes as typical example, are cell-derived vesicles comprising lipid bilayer with a diameter approximately 100 nm. sEVs are endogenous delivery vehicles that deliver their contents such as nucleic acids and proteins to recipient cells. Because of their potential nature as endogenous delivery vehicles, therapeutic applications of sEVs as delivery systems of various drugs are expected. To develop sEV-based therapeutics, a variety of challenges should be overcome. In this review, we summarize the current status and future perspectives of therapeutic applications of sEVs. Several pharmaceutical and pharmacokinetic challenges will be discussed.

Biochemical and plasma lipid responses to pemafibrate in patients with primary biliary cholangitis.

AIM: Fibrate addition to ursodeoxycholic acid (UDCA) therapy has been shown to improve both liver biochemistry and long-term prognosis in primary biliary cholangitis (PBC) patients showing an incomplete biochemical response to UDCA alone. We herein describe the clinical outcome of seven cases of PBC that received the new selective peroxisome proliferator-activated receptor α modulator, pemafibrate, in combination with UDCA therapy to investigate the biochemical and plasma lipid responses to the drug. METHODS: Of 124 initially enrolled PBC patients, 12 treated with UDCA alone and seven receiving UDCA plus bezafibrate showed alkaline phosphatase (ALP) levels above the upper limit of normal (330 U/L). Ultimately, seven patients with PBC and dyslipidemia who had agreed to biweekly visits at our hospital for UDCA plus pemafibrate combination therapy were retrospectively analyzed. RESULTS: In the four cases that switched from bezafibrate to pemafibrate, ALP became significantly decreased (0.031) and γ-glutamyltransferase tended to decrease (0.063) over the 3 months following pemafibrate addition. Two patients showed a greater than 50% reduction in ALP. No remarkable differences were observed for plasma lipid levels, alanine aminotransferase, aspartate aminotransferase, or the liver fibrosis marker Mac-2 binding protein glycosylation isomer between these time points. No adverse drug reactions were recorded. CONCLUSIONS: Pemafibrate might be another option for PBC patients with an incomplete response to UDCA therapy.

Induction of IFN-λ3 as an additional effect of nucleotide, not nucleoside, analogues: a new potential target for HBV infection.

OBJECTIVE: The clinical significance of polymorphisms in the interleukin-28B gene encoding interferon (IFN)-λ3, which has antiviral effects, is known in chronic HCV but not in HBV infection. Thus, we measured IFN-λ3 levels in patients with HBV and investigated its clinical significance and association with nucleos(t)ide (NUC) analogue administration. DESIGN: Serum IFN-λ3 level was measured in 254 patients with HBV with varying clinical conditions using our own high sensitivity method. The resulting values were compared with various clinical variables. In addition, cell lines originating from various organs were cultured with NUCs, and the production of IFN-λ3 was evaluated. RESULTS: Higher serum IFN-λ3 levels were detected in the patients treated with nucleotide analogues (adefovir or tenofovir) compared with those treated with nucleoside analogues (lamivudine or entecavir). There were no other differences in the clinical background between the two groups. A rise in the serum IFN-λ3 levels was observed during additional administration of the nucleotide analogues. In vitro experiments showed that the nucleotide analogues directly and dose-dependently induced IFN-λ3 production only in colon cancer cells. Furthermore, the supernatant from cultured adefovir-treated colon cancer cells significantly induced IFN-stimulated genes (ISGs) and inhibited hepatitis B surface antigen (HBsAg) production in hepatoma cells, as compared with the supernatant from entecavir-treated cells. CONCLUSIONS: We discovered that the nucleotide analogues show an additional pharmacological effect by inducing IFN-λ3 production, which further induces ISGs and results in a reduction of HBsAg production. These findings provide novel insights for HBV treatment and suggest IFN-λ3 induction as a possible target.

Past history of hepatocellular carcinoma is an independent risk factor of treatment failure in patients with chronic hepatitis C virus infection receiving direct-acting antivirals.

Direct-acting antiviral (DAA) treatment can achieve a high sustained virological response (SVR) rate in patients with hepatitis C virus (HCV) infection regardless of a history of hepatocellular carcinoma (HCC [+]). We examined 838 patients (370 men, median age: 69 years) who were treated with DAAs for comparisons of clinical findings between 79 HCC (+) (9.4%) and 759 HCC (-) (90.6%) patients and associations with treatment outcome. Male frequency was significantly higher in the HCC (+) group (60.8% vs 42.4%, P = 0.006). There were significant differences between the HCC (+) and HCC (-) groups for platelet count (115 vs 152 ×109 /L, P < 0.001), baseline alpha fetoprotein (AFP) (9.9 vs 4.5 ng/mL, P < 0.001) and the established fibrosis markers of FIB-4 index (4.7 vs 3.0, P < 0.001), AST-to-platelet ratio index (APRI) (1.1 vs 0.7, P = 0.009), M2BPGi (3.80 vs 1.78 COI, P < 0.001) and autotaxin (1.91 vs 1.50 mg/L, P < 0.001). The overall SVR rate was 94.7% and significantly lower in the HCC (+) group (87.3 vs 95.5%, P = 0.001). Multivariate analysis revealed that a history of HCC was independently associated with DAA treatment failure (odds ratio: 3.56, 95% confidence interval: 1.32-9.57, P = 0.01). In conclusion, patients with chronic HCV infection and prior HCC tended to exhibit more advanced disease progression at DAA commencement. HCC (+) status at the initiation of DAAs was significantly associated with adverse therapeutic outcomes. DAA treatment for HCV should therefore be started as early as possible, especially before complicating HCC.

Quantitative analysis of serum chemokines associated with treatment failure of direct-acting antivirals in chronic hepatitis C.

Although serum chemokine levels have been reported to influence the outcome of interferon-based treatment in patients with chronic hepatitis C, their effect on the hepatitis C virus (HCV) response to direct-acting antiviral agents (DAAs), which can achieve high rates of a sustained virological response (SVR), is largely unknown. To clarify this relationship, 9 chemokines (eotaxin, GRO-α, IL-8, IP-10, MCP-1, MIP-1α, MIP-1ß, RANTES, and SDF-1α) were quantified before, during, and after DAA treatment using serum samples obtained from 57 patients with chronic hepatitis C. All baseline median chemokine levels were significantly higher in patients with chronic hepatitis C than in healthy subjects (P < 0.05). In particular, lower MIP-1ß (≤71.5 pg/mL) and higher RANTES (>671.5 pg/mL) levels were significantly associated with patients who failed to clear HCV RNA (P = 0.0039 and 0.013, respectively). Prediction of a clinical response based on a combination of these chemokines demonstrated high sensitivity (82%), specificity (85%), negative predictive value (95%), and area under the curve (0.833). The non-SVR rate (56.3%; 9 of 16) was significantly higher in patients with low MIP-1ß and high RANTES compared with other combinations. Moreover, baseline MIP-1ß and RANTES were both additive and independent for predicting a non-SVR. Apart from an increase in eotaxin, all chemokines became decreased in patients with a SVR. In conclusion, a combination of serum MIP-1ß and RANTES levels may be predictive of a treatment response to DAAs in Japanese patients with chronic hepatitis C.

Development of a Synthetic Method for Multifunctionalized Pyrroles Using Isocyanide Dichloride as a Key Intermediate.

Multifunctionalized pyrrole derivatives were synthesized using a highly efficient method based on the Michael addition of carbanions generated in situ from isocyanide dichloride to α,ß-unsaturated carbonyl compounds. The reactions proceeded smoothly to afford the pyrrole derivatives in good to high yields. A wide range of Michael acceptors, such as α,ß-unsaturated carbonyl compounds and nitroolefin, were successfully applied to this reaction.

Serum autotaxin is a useful liver fibrosis marker in patients with chronic hepatitis B virus infection.

AIM: Autotaxin (ATX) is a secreted enzyme that is considered to be associated with liver damage as well as fibrosis. This study assessed the ability of ATX to diagnose liver fibrosis in patients with chronic hepatitis B virus (HBV) infection. METHODS: Serum ATX levels were retrospectively evaluated in 101 treatment-naïve patients with HBV-related chronic hepatitis or cirrhosis, all of whom had undergone liver biopsy at our hospital. RESULTS: Serum ATX concentration increased significantly according to liver fibrosis stage in overall (r = 0.46, P < 0.0001), male (r = 0.55, P < 0.0001), and female (r = 0.52, P = 0.0006) patient groups. When analyzed by gender, serum ATX was one of the most reliable markers for all fibrosis stages compared with other tested non-invasive markers, which included hyaluronic acid, type IV collagen 7S, aspartate aminotransferase-to-platelet ratio index, and fibrosis index based on four factors, according to receiver operating characteristic curve analysis. CONCLUSION: Based on this histologically proven data, ATX represents a novel non-invasive biomarker for liver fibrosis in HBV-infected patients.

Miglitol attenuates non-alcoholic steatohepatitis in diabetic patients.

AIM: Postprandial hyperglycemia is frequently accompanied by non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH). Although α-glucosidase inhibitors (αGIs) can slow glucose absorption from the intestine and suppress the surge of circulating glucose concentration after meals, it remains unclear whether αGIs are also beneficial for NASH. The aim of this prospective study was to examine the efficacy and safety of miglitol, a typical αGI, for NASH. METHODS: Seventeen patients with histologically confirmed NASH and hemoglobin A1c (HbA1c) >6.5% were treated with miglitol (150 mg/day) for 12 months. The changes in clinical parameters and liver histology were analyzed. RESULTS: All patients completed the 12-month miglitol treatment course with no severe adverse events. The treatment significantly decreased body mass index, serum alanine aminotransferase levels, and HbA1c (all P < 0.001). Post-treatment liver biopsy of 11 patients revealed significant improvements in steatosis (from 2.2 ± 0.6 to 1.5 ± 0.7, P = 0.001), lobular inflammation (from 1.8 ± 0.8 to 1.3 ± 0.5, P = 0.014), portal inflammation scores (from 0.6 ± 0.5 to 0.1 ± 0.3, P = 0.025), and NAFLD activity score (from 5.5 ± 1.5 to 3.9 ± 1.4, P = 0.012). Fibrosis and hepatocyte ballooning scores were unchanged. CONCLUSIONS: Miglitol appears to safely ameliorate NASH activity by attenuation of steatosis and lobular/portal inflammation. Appropriately powered controlled trials are warranted to validate our results.

Maternal undernutrition during early pregnancy inhibits postnatal growth of the tibia in the female offspring of rats by alteration of chondrogenesis.

Epidemiological research has suggested that birth weights are correlated with adult leg lengths. However, the relationship between prenatal undernutrition (UN) and postnatal leg growth remains controversial. We investigated the effects of UN during early pregnancy on postnatal hindlimb growth and determined whether early embryonic malnutrition affects the functions of postnatal chondrocytes in rats. Undernourished Wistar dams were fed 40% of the daily intake of rats in the control groups from gestational days 5.5-11.5, and femurs, tibias, and trunks or spinal columns were morphologically measured at birth and at 16 weeks of age in control and undernourished offspring of both sexes. We evaluated cell proliferation and differentiation of cultured chondrocytes derived from neonatal tibias of female offspring and determined chondrocyte-related gene expression levels in neonatal epiphysis and embryonic limb buds. Tibial lengths of undernourished female, but not male, offspring were longer at birth and shorter at 16 weeks of age (p < .05) compared with those of control rats. In chondrocyte culture studies, stimulating effects of IGF-1 on cell proliferation (p < .01) were significantly decreased and levels of type II collagen were lower in female undernourished offspring (p < .05). These phenomena were accompanied by decreased expression levels of Col2a1 and Igf1r and increased expression levels of Fgfr3 (p < .05), which might be attributable to the decreased expression of specificity protein 1 (p < .05), a key transactivator of Col2a1 and Igf1r. In conclusion, UN stress during early pregnancy reduces postnatal tibial growth in female offspring by altering the function of chondrocytes, likely reflecting altered expression of gene transactivators.

A case of liver abscess co-infected with Desulfovibrio desulfuricans and Escherichia coli and review of the literature.

A 73-year-old woman was admitted with consciousness disturbance following a fever. Abdominal computed tomography revealed a large liver abscess with which the presence of Desulfovibrio desulfuricans and Escherichia coli was confirmed by thorough blood and abscess content culture. Empiric meropenem treatment was switched to cefoperazone/sulbactam, followed by ampicillin/sulbactam based on susceptibility testing. Desulfovibrio desulfuricans is a common bacterium that rarely causes liver abscess and may be overlooked during co-infection due to overgrowth of the accompanying bacteria. Clinicians should bear Desulfovibrio desulfuricans in mind and select the appropriate antibiotics according to susceptibility testing when anaerobic bacteria are detected in a liver abscess.

Accelerated growth of B16BL6 tumor in mice through efficient uptake of their own exosomes by B16BL6 cells.

Exosomes are extracellular vesicles released by various cell types and play roles in cell-cell communication. Several studies indicate that cancer cell-derived exosomes play important pathophysiological roles in tumor progression. Biodistribution of cancer cell-derived exosomes in tumor tissue is an important factor for determining their role in tumor proliferation; however, limited studies have assessed the biodistribution of exosomes in tumor tissues. In the present study, we examined the effect of cancer-cell derived exosomes on tumor growth by analyzing their biodistribution. Murine melanoma B16BL6-derived exosomes increased the proliferation and inhibited the apoptosis of B16BL6 cells, which was associated with an increase and decrease in the levels of proliferation- and apoptosis-related proteins, respectively. GW4869-induced inhibition of exosome secretion decreased the proliferation of B16BL6 cells, and treatment of GW4869-treated cells with B16BL6-derived exosomes restored their proliferation. Next, we treated B16BL6 tumors in mice with B16BL6-derived exosomes and examined the biodistribution and cellular uptake of these exosomes. After the intratumoral injection of radiolabeled B16BL6-derived exosomes, most radioactivity was detected within the tumor tissues of mice. Fractionation of cells present in the tumor tissue showed that fluorescently labeled exosomes were mainly taken up by B16BL6 cells. Moreover, intratumoral injection of B16BL6-derived exosomes promoted tumor growth, whereas intratumoral injection of GW4869 suppressed tumor growth. These results indicate that B16BL6 cells secrete and take up their own exosomes to induce their proliferation and inhibit their apoptosis, which promotes tumor progression.

Association between serum soluble CD14 and IL-8 levels and clinical outcome in primary biliary cholangitis.

BACKGROUND & AIMS: Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by portal inflammation and immune-mediated destruction of intrahepatic bile ducts that often leads to liver decompensation and liver failure. Although the biochemical response to ursodeoxycholic acid (UDCA) can predict disease outcome in PBC, few biomarkers have been identified as prognostic tools applicable prior to UDCA treatment. We therefore sought to identify such indicators of long-term outcome in PBC in the Japanese population. METHODS: The prebiopsy serum samples and subsequent clinical data of 136 patients with PBC treated with UDCA were analysed over a median follow-up period of 8.8 years. Serum levels of biomarkers related to microbial translocation (sCD14, EndoCAb and I-FABP) were measured along with those of 33 cytokines and chemokines and additional auto-antibodies. Associations between the tested parameters and the clinical outcomes of liver decompensation and liver-related death/liver transplantation were evaluated using the Cox proportional hazards model with stepwise methods and Kaplan-Meier analysis. RESULTS: Elevated levels of serum IL-8, and sCD14 before UDCA therapy were significantly associated with both liver decompensation and liver-related death/liver transplantation. In multivariate analyses, IL-8≥46.5 pg/mL or sCD14≥2.0 µg/mL at enrolment demonstrated the same results. Kaplan-Meier analysis also revealed IL-8 and sCD14 to be significantly associated with a poor outcome. sCD14 was significantly correlated with IL-8. EndoCAb and I-FABP were not related to disease outcome. CONCLUSIONS: Serum IL-8 and sCD14 levels before UDCA therapy represent noninvasive surrogate markers of prognosis in patients with PBC.

Development of a One-Pot Synthetic Method for Multifunctional Oxazole Derivatives Using Isocyanide Dichloride.

A one-pot synthetic method was developed for multifunctional dihydrooxazole and oxazole derivatives. New reaction sequences were developed involving the formation of isocyanide dichloride, an aldol-type reaction with aldehydes, and a nucleophilic addition-elimination reaction, which efficiently afforded the dihydrooxazole and oxazole scaffolds.

Serum Wisteria floribunda agglutinin-positive human Mac-2 binding protein may predict liver fibrosis and progression to hepatocellular carcinoma in patients with chronic hepatitis B virus infection.

AIM: Serum glycosylated Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA+ -M2BP) is a reliable, non-invasive marker of liver fibrosis. This study assessed the ability of WFA+ -M2BP to diagnose liver fibrosis in patients with chronic hepatitis B virus (HBV) infection and evaluated WFA+ -M2BP as a predictor of hepatocellular carcinoma (HCC) development. METHODS: Serum WFA+ -M2BP values were retrospectively evaluated in 112 treatment-naïve patients with HBV-related chronic hepatitis and cirrhosis who had undergone liver biopsy at our hospital. RESULTS: Serum WFA+ -M2BP levels were significantly related with liver fibrosis (r = 0.3725, P = 0.001). Fibrosis stage F2, F3, and F4 had a cut-off index of 0.94, 1.26, and 1.26, respectively. For diagnosing F ≥ 2 fibrosis, the area under the receiver-operating characteristic curve for WFA+ -M2BP was 0.713 and comparable with those of other non-invasive fibrosis markers, such as hyaluronic acid, type IV collagen 7S, aspartate aminotransferase-to-platelet ratio index, fibrosis-4 index, serum albumin, and platelet count. Multivariate analysis identified male, WFA+ -M2BP ≥0.71, alanine aminotransferase ≥80 IU/L, and platelet count <14.5 × 109 /L as independent risk factors for the development of HCC in patients with HBV infection. CONCLUSIONS: Serum WFA+ -M2BP values appear to be useful for assessing liver fibrosis stage and are independently associated with HCC development in patients with chronic HBV infection.

Clinicopathological characteristics of non-B non-C hepatocellular carcinoma without past hepatitis B virus infection.

AIM: Past hepatitis B virus (HBV) infection is considered a risk factor for hepatocarcinogenesis, but the clinicopathological characteristics of non-B non-C hepatocellular carcinoma (NBNC-HCC) excluding past HBV infection have not been investigated. This study aimed to clarify the clinicopathological features of strictly defined NBNC-HCC. METHODS: Among HCC patients who underwent surgical resection at our affiliated hospitals in Nagano prefecture, Japan, between 1996 and 2012, 77 were negative for serum anti-HBV core/surface antibodies in addition to HBV surface antigen and anti-hepatitis C virus antibody without signs of autoimmune liver disease, Wilson disease, or hemochromatosis. These patients were divided into the alcohol intake-positive group (ethanol intake >20 g/day, n = 31), non-alcoholic fatty liver group (steatosis >5% and ethanol intake <20 g/day, n = 30), and cryptogenic group (no ethanol intake or steatosis, n = 16). Preoperative clinical parameters, tumor and background liver pathology, and prognosis were analyzed. RESULTS: Advanced fibrosis and steatosis were detected in 64% and 60% of all patients, respectively. Approximately 85% of the alcohol intake-positive patients had advanced fibrosis. Non-alcoholic fatty liver HCC subjects had the highest body mass index and prevalence of diabetes, but 30-40% had none to mild fibrosis. The cryptogenic group of HCC patients had the lowest incidence of accompanying hepatic inflammation/fibrosis but the largest tumor size. Recurrence/survival rates were comparable among the groups. CONCLUSIONS: Liver fibrosis and steatosis are risk factors of HCC regardless of past HBV infection and ethanol consumption. The present results also indicate the possibility of hepatocarcinogenesis independent of hepatic steatosis, inflammation and fibrosis, ethanol intake, and past HBV infection.

Rapid and coordinated processing of global motion images by local clusters of retinal ganglion cells.

Even when the body is stationary, the whole retinal image is always in motion by fixational eye movements and saccades that move the eye between fixation points. Accumulating evidence indicates that the brain is equipped with specific mechanisms for compensating for the global motion induced by these eye movements. However, it is not yet fully understood how the retina processes global motion images during eye movements. Here we show that global motion images evoke novel coordinated firing in retinal ganglion cells (GCs). We simultaneously recorded the firing of GCs in the goldfish isolated retina using a multi-electrode array, and classified each GC based on the temporal profile of its receptive field (RF). A moving target that accompanied the global motion (simulating a saccade following a period of fixational eye movements) modulated the RF properties and evoked synchronized and correlated firing among local clusters of the specific GCs. Our findings provide a novel concept for retinal information processing during eye movements.

Steatogenesis in adult-onset type II citrullinemia is associated with down-regulation of PPARα.

SLC25A13 (citrin or aspartate-glutamate carrier 2) is located in the mitochondrial membrane in the liver and its genetic deficiency causes adult-onset type II citrullinemia (CTLN2). CTLN2 is one of the urea cycle disorders characterized by sudden-onset hyperammonemia due to reduced argininosuccinate synthase activity. This disorder is frequently accompanied with hepatosteatosis in the absence of obesity and ethanol consumption. However, the precise mechanism of steatogenesis remains unclear. The expression of genes associated with fatty acid (FA) and triglyceride (TG) metabolism was examined using liver samples obtained from 16 CTLN2 patients and compared with 7 healthy individuals. Although expression of hepatic genes associated with lipogenesis and TG hydrolysis was not changed, the mRNAs encoding enzymes/proteins involved in FA oxidation (carnitine palmitoyl-CoA transferase 1α, medium- and very-long-chain acyl-CoA dehydrogenases, and acyl-CoA oxidase 1), very-low-density lipoprotein secretion (microsomal TG transfer protein), and FA transport (CD36 and FA-binding protein 1), were markedly suppressed in CTLN2 patients. Serum concentrations of ketone bodies were also decreased in these patients, suggesting reduced mitochondrial ß-oxidation activity. Consistent with these findings, the expression of peroxisome proliferator-activated receptor α (PPARα), a master regulator of hepatic lipid metabolism, was significantly down-regulated. Hepatic PPARα expression was inversely correlated with severity of steatosis and circulating ammonia and citrulline levels. Additionally, phosphorylation of c-Jun-N-terminal kinase was enhanced in CTLN2 livers, which was likely associated with lower hepatic PPARα. Collectively, down-regulation of PPARα is associated with steatogenesis in CTLN2 patients. These findings provide a novel link between urea cycle disorder, lipid metabolism, and PPARα.

Production of infectious HCV genotype 1b virus in cell culture using a novel Set of adaptive mutations.

BACKGROUND: Despite the high prevalence of genotype 1b hepatitis C virus (HCV) among patients, a cell culture system that permits entire viral life cycle of genotype 1b isolates is limited. To develop a cell-cultured hepatitis C virus (HCVcc) of genotype 1b, the proper combination of HCV genomic variants and host cells is essential. HCV genomes isolated from patients with distinctive symptoms may provide the variants required to establish an HCVcc of genotype 1b. RESULTS: We first established subgenomic replicons in Huh7 cells using HCV cDNAs isolated from two patients: one with fulminant hepatitis after liver transplantation (TPF1) and another with acute hepatitis and moderate symptoms (sAH). Replicons established from TPF1 and sAH showed mutations in NS4B and in NS3 and NS5A, respectively. Using these replication machineries, we constructed HCV genomic RNAs for each isolate. Virus infectivity was evaluated by a focus-forming assay, which is dependent on the intracellular expression of core antigen, and production of virus particles was assessed by density-gradient centrifugation. Infectious virus was only observed in the culture medium of cells transfected with TFP1 HCV RNA. A chimeric genome with the structural segment (5'-untranslated region [UTR] through NS2) from sAH and the replication machinery (NS3 through 3'-UTR) from TPF1 exhibited greater infectivity than did TFP1, despite formation of deficient virus particles in sAH, suggesting that this genomic segment potentiates virus particle formation. To identify the responsible variants, infectious virus formation was assessed in a chimeric genome carrying parts of the sAH structural segment of the TPF1 genome. A variant in NS2 (M170T) was identified that enhanced infectious virus formation. HCVcc carrying an NS2 gene encoding the M170T substitution and adaptive mutations in NS4B (referred to as TPF1-M170T) infected naïve cured Huh7 cells in a CD81-dependent manner. CONCLUSIONS: We established a novel HCVcc of genotype 1b in Huh7 cells by introducing an amino acid variant in NS2 and adaptive mutations in NS4B from HCV genomic RNA isolated from a patient with fulminant HCV after liver transplantation.