Advancing the global public health agenda for NAFLD: a consensus statement

Non-alcoholic fatty liver disease (NAFLD) is a potentially serious liver disease that affects approximately one-quarter of the global adult population, causing a substantial burden of ill health with wide-ranging social and economic implications. It is a multisystem disease and is considered the hepatic component of metabolic syndrome. Unlike other highly prevalent conditions, NAFLD has received little attention from the global public health community. Health system and public health responses to NAFLD have been weak and fragmented, and, despite its pervasiveness, NAFLD is largely unknown outside hepatology and gastroenterology. There is only a nascent global public health movement addressing NAFLD, and the disease is absent from nearly all national and international strategies and policies for non-communicable diseases, including obesity. In this global Delphi study, a multidisciplinary group of experts developed consensus statements and recommendations, which a larger group of collaborators reviewed over three rounds until consensus was achieved. The resulting consensus statements and recommendations address a broad range of topics - from epidemiology, awareness, care and treatment to public health policies and leadership - that have general relevance for policy-makers, health-care practitioners, civil society groups, research institutions and affected populations. These recommendations should provide a strong foundation for a comprehensive public health response to NAFLD.

The phenobarbital response enhancer module in the human bilirubin UDP-glucuronosyltransferase UGT1A1 gene and regulation by the nuclear receptor CAR

The UDP-glucuronosyltransferase, UGT1A1, is the critical enzyme responsible for detoxification of the potentially neurotoxic bilirubin by conjugating it with glucuronic acid. For decades, phenobarbital (PB) treatment for hyperbilirubinemia has been known to increase expression of the UGT1A1 gene in liver. We have now delineated the PB response activity to a 290-bp distal enhancer sequence (-3483/-3194) of the UGT1A1 gene. The enhancer contains 3 putative nuclear receptor motifs, and it was activated by the nuclear orphan receptor, human constitutive active receptor (hCAR), in cotransfected HepG2 cells. Bacterially expressed hCAR, acting as a heterodimer with in vitro-translated retinoid X receptor (RXRalpha), only bound to 1 of the 3 NR motifs, named gtNR1 in a gel-shift assay. Consistently, mutations of the gtNR1 site significantly decreased the activation by hCAR of the 290-bp DNA in transfection assays. Moreover, the 290-bp DNA was effectively activated in mouse primary hepatocytes in response to PB, offering an excellent clinical test for the examination of the responsiveness of the UGT1A1 to PB in the human population, particularly individuals with hyperbilirubinemia.

Identification of a defect in the UGT1A1 gene promoter and its association with hyperbilirubinemia

The UDP-glucuronosyltransferase UGT1A1 plays a critical role in the detoxification of potentially neurotoxic bilirubin by conjugating it with glucuronic acid. We identified a polymorphism that results in a T to G substitution at nucleotide number -3263 of the phenobarbital-responsive enhancer module of the UGT1A1 gene, thereby significantly decreasing transcriptional activity as indicated by the luciferase-reporter assay. At least one T-3263G allele was found in 21 of 25 subjects with mild hyperbilirubinemia (Gilbert's syndrome); this frequency (0.58) was significantly higher than that in normobilirubinemic controls (0.17; n = 8 of 27). Homozygous mutations in the TATA element (A[TA](7)TAA) or at nucleotide 211 of exon 1 (G to A substitution) were found in 5 and 2 of the hyperbilirubinemic group, respectively, while 12 of these subjects were double heterozygotes for the T-3263G and G211A mutations. Plasma total bilirubin levels in these double heterozygotes were significantly higher than those in control subjects carrying one or other of these mutations singly, indicating that compound heterozygous mutations may result in more strongly reduced UGT1A1 activity. Our results indicate that homozygosity and compound heterozygosity for mutations in the UGT1A1 gene promoter (T-3263G and A[TA](7)TAA) and/or exon 1 of the gene (G211A) could explain the hyperbilirubinemia seen in the majority of individuals with Gilbert's syndrome.

Endoscopic submucosal dissection for early gastric cancers and large flat adenomas

BACKGROUND AND STUDY AIM

Endoscopic submucosal dissection (ESD) is a new diagnostic and treatment technique for early gastric cancer (EGC). The present study aims to identify the technical feasibility, operation time, and complications associated with ESD.

METHODS

We reviewed the patients who underwent ESD for EGCs at Maebashi Red Cross Hospital.

RESULTS

There were 160 patients with 171 EGCs treated by ESD. The mean age was 71.4 +/- 8.9 years (median 72). The rate for one-piece resection with tumor-free margins was 94.2 % (161/171), and was 93.2 % (82/88) for large lesions (> 20 mm) and 92.1 % (35/38) for ulcerative lesions. The median operation time was 80 min (range 10-600 min). Evidence of immediate bleeding was found in 2.9 % (5/171), delayed bleeding was seen in 7.6 % (13/171), and perforation was observed in 3.5 % (6/171) of the lesions. All patients with complications, including perforation, were successfully treated endoscopically. There were no local or distant metastases in the lesions which met our indication criteria for ESD.

CONCLUSION

The present study shows the technical feasibility of ESD, which provides the capability of one-piece resection even in large and ulcerative lesions.

Hepatocellular carcinoma with portal vein tumor thrombosis: clinical characteristics, prognosis, and patient survival analysis

Hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is associated with a poor prognosis. New therapeutic modalities, such as continuous hepatic arterial infusion chemotherapy (CHAIC), have recently been reported to be promising strategies. The aim of this study was to evaluate the clinical characteristics, prognosis, and survival of patients with PVTT according to treatment regimen. One hundred ninety-three patients with HCC complicated with PVTT at the time of diagnosis were included in this study. All patients were newly diagnosed to have HCC and were observed from January 1992 to December 2003. CHAIC was performed using an implanted drug delivery system with low-dose cisplatin and 5-fluorouracil. Clinical characteristics, prognosis, and patient survival were analyzed by the Kaplan-Meier method and Cox's proportional hazards model. The mean age of the patients complicated with PVTT was 64.3+/-10.3 years (range, 20-88 years). The survival of the 193 patients with PVTT was 37.5%, 24.0%, 18.9%, and 8.3% at 1, 2, 3, and 5 years, respectively. According to treatment, the survival of patients who underwent surgical treatment was the best, followed by CHAIC, transcatheter arterial infusion/embolization, and supportive care. The 3-year survivals for each treatment regimen were 53.0%, 19.3%, 15.0%, and 4.0%, respectively. Although the survival of patients who received surgical treatment was best, such patients were restricted. There was no difference in survival between treated and untreated patients demonstrating Child-Pugh grade C. In Child B patients, treatment for HCC significantly increased survival (P<0.01). Cox's proportional hazards model revealed the Child-Pugh classification to be an independent prognostic factor for patients with HCC and PVTT (P<0.01). We conclude that the prognosis of HCC with PVTT was quite poor. The treatment did not improve the survival of Child C patients. As a result, the prevention, early diagnosis, and development of new treatment strategies are required.

Estrogen activation of the nuclear orphan receptor CAR (constitutive active receptor) in induction of the mouse Cyp2b10 gene

The nuclear orphan receptor CAR (constitutively active receptor or constitutive androstane receptor) can be activated in response to xenochemical exposure, such as activation by phenobarbital of a response element called NR1 found in the CYP2B gene. Here various steroids were screened for potential endogenous chemicals that may activate CAR, using the NR1 enhancer and Cyp2b10 induction in transfected HepG2 cell and/or in mouse primary hepatocytes as the experimental criteria. 17beta-Estradiol and estrone activated NR1, whereas estriol, estetrol, estradiol sulfate, and the synthetic estrogen diethylstilbestrol did not. On the other hand, progesterone and androgens repressed NR1 activity in HepG2 cells, and the repressed NR1 activity was fully restored by estradiol. Moreover, estrogen treatment elicited nuclear accumulation of CAR in the mouse livers, as well as primary hepatocytes, and induced the endogenous Cyp2b10 gene. Ovariectomy did not affect either the basal or induced level of CAR in the nucleus of the female livers, while castration slightly increased the basal and greatly increased the induced levels in the liver nucleus of male mice. Thus, endogenous estrogen appears not to regulate CAR in female mice, whereas endogenous androgen may be the repressive factor in male mice. Estrogen at pharmacological levels is an effective activator of CAR in both female and male mice, suggesting a biological and/or toxicological role of this receptor in estrogen metabolism. In addition to mouse CAR, estrogens activated rat CAR, whereas human CAR did not respond well to the estrogens under the experimental conditions.

A ligand for peroxisome proliferator activated receptor gamma inhibits cell growth and induces apoptosis in human liver cancer cells

BACKGROUND AND AIMS

Induction of apoptosis of cancer cells through ligands of nuclear hormone receptors (NHRs) is a new approach in cancer therapy. Recently, one of the NHRs, peroxisome proliferator activated receptor gamma (PPARgamma), has been shown to influence cell growth in certain cancer cells although its effect on hepatocellular carcinoma (HCC) has not been analysed.

METHODS

Experiments were conducted using three human liver cancer cell lines, PLC/PRF/5, Hep G2 and HuH-7, in vitro. These cells were exposed to troglitazone, a synthetic ligand for PPARgamma, and the effects on cell growth were analysed.

RESULTS

Expression of PPARgamma mRNA was detected in all three liver cancer cell lines. Activation of PPARgamma by troglitazone caused a marked growth inhibition in a dose dependent manner in three hepatoma cell lines. The DNA fragmentation ELISA assay and Hoechst 33258 staining revealed that the growth inhibitory effect by adding troglitazone was due to apoptosis of PLC/PRF/5, which strongly expressed PPARgamma. Troglitazone also induced activation of the cell death protease, caspase 3, but not caspase 8, in PLC/PRF/5 cells. However, expression levels of antiapoptotic factor bcl-2 and apoptosis inducing factor bax were not affected.

CONCLUSION

Our study showed that PPARgamma was expressed in human liver cancer cells and that the ligand for PPARgamma, troglitazone, inhibited the growth of these cells by inducing apoptosis through caspase 3 activation, indicating that troglitazone could be potentially useful as an apoptosis inducer for the treatment of HCC.

Atezolizumab plus bevacizumab versus lenvatinib or sorafenib in non-viral unresectable hepatocellular carcinoma: an international propensity score matching analysis

BACKGROUND

A growing body of evidence suggests that non-viral hepatocellular carcinoma (HCC) might benefit less from immunotherapy.

MATERIALS AND METHODS

We carried out a retrospective analysis of prospectively collected data from consecutive patients with non-viral advanced HCC, treated with atezolizumab plus bevacizumab, lenvatinib, or sorafenib, in 36 centers in 4 countries (Italy, Japan, Republic of Korea, and UK). The primary endpoint was overall survival (OS) with atezolizumab plus bevacizumab versus lenvatinib. Secondary endpoints were progression-free survival (PFS) with atezolizumab plus bevacizumab versus lenvatinib, and OS and PFS with atezolizumab plus bevacizumab versus sorafenib. For the primary and secondary endpoints, we carried out the analysis on the whole population first, and then we divided the cohort into two groups: non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) population and non-NAFLD/NASH population.

RESULTS

One hundred and ninety patients received atezolizumab plus bevacizumab, 569 patients received lenvatinib, and 210 patients received sorafenib. In the whole population, multivariate analysis showed that treatment with lenvatinib was associated with a longer OS [hazard ratio (HR) 0.65; 95% confidence interval (CI) 0.44-0.95; P = 0.0268] and PFS (HR 0.67; 95% CI 0.51-0.86; P = 0.002) compared to atezolizumab plus bevacizumab. In the NAFLD/NASH population, multivariate analysis confirmed that lenvatinib treatment was associated with a longer OS (HR 0.46; 95% CI 0.26-0.84; P = 0.0110) and PFS (HR 0.55; 95% CI 0.38-0.82; P = 0.031) compared to atezolizumab plus bevacizumab. In the subgroup of non-NAFLD/NASH patients, no difference in OS or PFS was observed between patients treated with lenvatinib and those treated with atezolizumab plus bevacizumab. All these results were confirmed following propensity score matching analysis. By comparing patients receiving atezolizumab plus bevacizumab versus sorafenib, no statistically significant difference in survival was observed.

CONCLUSIONS

The present analysis conducted on a large number of advanced non-viral HCC patients showed for the first time that treatment with lenvatinib is associated with a significant survival benefit compared to atezolizumab plus bevacizumab, in particular in patients with NAFLD/NASH-related HCC.

Zinc supplementation enhances the response to interferon therapy in patients with chronic hepatitis C

We evaluated the synergistic effect of zinc supplementation on the response to interferon (IFN) therapy in patients with intractable chronic hepatitis C in a pilot study using natural IFN-alpha with or without zinc. No clinical differences were observed between patients treated with IFN alone (n=40) and IFN with polaprezinc (IFN + Zn, n=35). All patients were positive for HCV genotype Ib and had more than 105 copies of the virus/mL serum. Ten million units of natural IFN-alpha was administered daily for 4 weeks followed by the same dose every other day for 20 weeks. In the IFN + Zn group, patients received an additional dose of 150 mg/day polaprezinc orally throughout the 24-week IFN course. No additional side-effects of polaprezinc were noted but four out of 40 IFN alone treatment and three out of 35 IFN + Zn group withdrew because of side-effects. Complete response (CR) was defined as negative HCV RNA in the serum on PCR and normal aminotransferase level 6 months after therapy. Incomplete response (IR) was normal liver enzyme and positive serum HCV RNA. Both of them were evaluated at the 6 months after the completion of the treatment. Patients with higher levels of serum HCV (more than 5 x 105 copies/mL) had little response in both treatment groups. Patients with moderate amount of HCV (105 to 4.99 x 105/mL) showed high response rates in combination group (CR: 11/27, 40.7%; CR + IR 15/27, 64.3%), better than IFN alone (CR: 2/15, 18.2%; CR + IR: 2/15, 18.2%). Serum zinc levels were higher in patients with IFN + Zn group than in the IFN group. Our results indicate that zinc supplementation enhances the response to interferon therapy in patients with intractable chronic hepatitis C.

Endoscopic submucosal dissection for rectal tumors

BACKGROUND AND STUDY AIM

Endoscopic submucosal dissection (ESD) has recently been developed for one-piece resection of gastric tumors. In order to improve patients' quality of life, it may be desirable to use the same technique for rectal tumors.

METHODS

35 consecutive patients with rectal tumors were enrolled. ESD was carried out using the same technique as for the stomach. The efficacy, technical feasibility, operation time, complications, and follow-up results were assessed.

RESULTS

The mean size of the epithelial tumors was 26.2 +/- 14.0 mm, and the rates of one-piece resection and one-piece resection with tumor-free margins were 73.3% (22 of 30) and 70.0% (21 of 30), respectively. The median operation time was 70 min (range 8-360 min). All five carcinoid tumors were completely resected. No patient needed blood transfusion or had the complication of problematic bleeding. Perforation during ESD occurred in one patient (2.9%), who was managed with conservative medical treatment after endoscopic closure of the perforation. Excluding seven patients, who either underwent additional surgery or whose follow-up period was less than 1 year, all 23 patients with epithelial tumors were free of recurrence during a mean follow-up period of 25.7 months (range 12-53 months).

CONCLUSIONS

ESD was thus found to be feasible for the treatment of rectal tumors, with promising results although the follow-up periods were short. ESD may therefore be indicated for rectal tumors which are not resectable en bloc by conventional procedures, in order to improve the patients' quality of life.

A prospective randomized controlled study of long-term combination therapy using ursodeoxycholic acid and bezafibrate in patients with primary biliary cirrhosis and dyslipidemia

OBJECTIVES

The aim of this study was to assess the long-term prognosis, efficacy, and safety of combination therapy using ursodeoxycholic acid (UDCA) and bezafibrate (BF) for primary biliary cirrhosis (PBC) patients exhibiting dyslipidemia.

METHODS

We performed a prospective, randomized, controlled, multicenter study to compare the long-term clinical results between combination therapy and UDCA monotherapy for patients refractory to UDCA monotherapy. Twenty-seven consecutive PBC patients were enrolled.

RESULTS

The median treatment period in the UDCA and UDCA+BF groups was 107 and 110 months, respectively. The serum alkaline phosphatase (ALP) levels and the Mayo risk score in the combination therapy group (mean 290 IU/l and 0.91, respectively) were significantly lower than those in the UDCA monotherapy group (mean 461 IU/l and 1.42, respectively) at 8 years after the beginning of the study (P<0.05). The serum creatinine levels in the combination therapy group (mean 0.94 mg/dl) were significantly higher than those in the UDCA monotherapy group (mean 0.56 mg/dl) at 8 years after the beginning of the study (P<0.05). However, the survival rate was not significantly different between the groups. We observed dose reduction or discontinuation of the administration of BF, but not UDCA, due to renal dysfunction or muscle pain.

CONCLUSIONS

Long-term combination therapy significantly improved the serum ALP levels and the Mayo risk score. However, the survival rate was not significantly different between the groups. In addition, long-term combination therapy significantly increased the serum creatinine levels. We should pay close attention to adverse events during this long-term combination therapy.

Atezolizumab plus bevacizumab versus lenvatinib for unresectable hepatocellular carcinoma: a large real-life worldwide population

BACKGROUND AND AIMS

Atezolizumab plus bevacizumab and lenvatinib have not been compared in a randomised controlled trial. We conducted a retrospective multi-centre study to compare the clinical efficacy and safety of lenvatinib and atezolizumab with bevacizumab as a first-line treatment for patients with unresectable HCC in the real-world scenario.

METHODS

Clinical features of lenvatinib and atezolizumab plus bevacizumab patients were balanced through inverse probability of treatment weighting (IPTW) methodology, which weights patients' characteristics and measured outcomes of each patient in both treatment arms. Overall survival (OS) was the primary end-point.

RESULTS

The analysis included 1341 patients who received lenvatinib, and 864 patients who received atezolizumab plus bevacizumab. After IPTW adjustment, atezolizumab plus bevacizumab did not show a survival advantage over lenvatinib HR 0.97 (p = 0.739). OS was prolonged by atezolizumab plus bevacizumab over lenvatinib in viral patients (HR: 0.76; p = 0.024). Conversely, OS was prolonged by lenvatinib in patients with non-alcoholic steatohepatitis/non-alcoholic fatty liver disease (HR: 1.88; p = 0.014). In the IPTW-adjusted population, atezolizumab plus bevacizumab provided better safety profile for most of the recorded adverse events.

CONCLUSION

Our study did not identify any meaningful difference in OS between atezolizumab plus bevacizumab and lenvatinib. Although some hints are provided suggesting that patients with non-alcoholic steatohepatitis/non-alcoholic fatty liver disease might benefit more from lenvatinib therapy and patients with viral aetiology more from atezolizumab plus bevacizumab.

SGLT1 in pancreatic α cells regulates glucagon secretion in mice, possibly explaining the distinct effects of SGLT2 inhibitors on plasma glucagon levels

Objectives

It is controversial whether sodium glucose transporter (SGLT) 2 inhibitors increase glucagon secretion via direct inhibition of SGLT2 in pancreatic α cells. The role of SGLT1 in α cells is also unclear. We aimed to elucidate these points that are important not only for basic research but also for clinical insight.

Methods

Plasma glucagon levels were assessed in the high-fat, high-sucrose diet (HFHSD) fed C57BL/6J mice treated with dapagliflozin or canagliflozin. RT-PCR, RNA sequence, and immunohistochemistry were conducted to test the expression of SGLT1 and SGLT2 in α cells. We also used αTC1 cells and mouse islets to investigate the molecular mechanism by which SGLT1 modulates glucagon secretion.

Results

Dapagliflozin, but not canagliflozin, increased plasma glucagon levels in HFHSD fed mice. SGLT1 and glucose transporter 1 (GLUT1), but not SGLT2, were expressed in αTC1 cells, mouse islets and human islets. A glucose clamp study revealed that the plasma glucagon increase associated with dapagliflozin could be explained as a response to acute declines in blood glucose. Canagliflozin suppressed glucagon secretion by inhibiting SGLT1 in α cells; consequently, plasma glucagon did not increase with canagliflozin, even though blood glucose declined. SGLT1 effect on glucagon secretion depended on glucose transport, but not glucose metabolism. Islets from HFHSD and db/db mice displayed higher SGLT1 mRNA levels and lower GLUT1 mRNA levels than the islets from control mice. These expression levels were associated with higher glucagon secretion. Furthermore, SGLT1 inhibitor and siRNA against SGLT1 suppressed glucagon secretion in isolated islets.

Conclusions

These data suggested that a novel mechanism regulated glucagon secretion through SGLT1 in α cells. This finding possibly explained the distinct effects of dapagliflozin and canagliflozin on plasma glucagon levels in mice.

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SGLT1, but not SGLT2, is expressed in αTC1 cells, mouse islets and human islets.

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SGLT2 inhibitor dapagliflozin increases plasma glucagon in diabetic mice.

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SGLT2/low potency SGLT1 inhibitor canagliflozin does not increase plasma glucagon.

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Canagliflozin suppresses glucagon secretion by inhibiting SGLT1 in α cells.

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Higher expression of SGLT1 in islets is associated with higher glucagon secretion.

Endoscopic treatment of rectal carcinoid tumors

BACKGROUND

Various methods have been reported for the endoscopic treatment of rectal carcinoid tumors. The present study was designed to identify the optimal treatment strategy for an endoscopic resection.

METHODS

Forty rectal carcinoid tumors of 38 patients were treated endoscopically. The indication criteria, complete resection rate, selection of treatment, local recurrence, distant metastases, and complications were analyzed. All tumors were estimated to measure 1 cm or less in diameter, without muscular invasion, atypical features, and lymph node metastases to the pararectal region.

RESULTS

Complete resection of the lesions was obtained in 75.0% (30/40). The complete resection rates were 20.0% (1/5) by conventional polypectomy, 84.6% (22/26) by a two-channel endoscopic mucosal resection, and 77.8% (7/9) by endoscopic submucosal dissection. The 10 cases that did not show a clear submucosal layer after initial endoscopic treatment received additional endoscopic microwave coagulation therapy. There were no local or distant recurrences in the followed-up periods (median, 6.4 years). No difference was observed in the complete resection rate between two-channel endoscopic mucosal resection and endoscopic submucosal dissection.

CONCLUSIONS

Small carcinoid tumors measuring less than 1 cm in diameter can therefore be managed endoscopically with no recurrence or spread. The selection of endoscopic treatment should be made after taking such factors as cost-effectiveness, expertise, and experience into careful consideration.

Functional gastrointestinal disorders in adolescents and quality of school life

BACKGROUND AND AIM

The prevalence of functional gastrointestinal disorders (FGID) in adolescents and their relationship to quality of school life (QOSL) are not fully understood. This study investigated the relationship between FGID and QOSL.

METHODS

Adolescents (10-17 years) were recruited from 40 schools. FGID diagnoses were based on the Questionnaire on Pediatric Gastrointestinal Symptoms-Rome III version (QPGS-RIII). QOSL was evaluated by a questionnaire and calculated as the QOSL score.

RESULTS

Five hundred and fifty-two of the 3976 students (13.9%) met the FGID criteria for one or more diagnoses according to the QPGS-RIII: 12.3% met the criteria for one, 1.5% for two or more. Irritable bowel syndrome (IBS) was the most common diagnosis (5.9%) followed by functional abdominal pain (3.1%). The prevalence of FGID was significantly higher in the female students in comparison to male students (P < 0.01). The prevalence of FGID was 9.5% in elementary school, 15.4% in junior high school, 26.0% in high school students, respectively. The prevalence of FGID was significantly increased with age (P < 0.01). The QOSL score of the patients with FGID was 10.9 ± 4.5 and that without FGID was 8.2 ± 2.8, respectively. The QOSL score of the patients with FGID was significantly worse than those without FGID (P < 0.01). The QOSL scores with IBS, aerophagia, and cyclic vomiting syndrome were significantly worse among the FGID (P < 0.01).

CONCLUSIONS

The prevalence of FGID in adolescents was relatively high. The presences of FGID worsen the QOSL score. Medical intervention and/or counseling are needed for such students to improve the QOSL.

New insights on the xenobiotic-sensing nuclear receptors in liver diseases--CAR and PXR--

The xenobiotic receptors CAR and PXR constitute two important members of the NR1I nuclear receptor family. They function as sensors of toxic byproducts derived from the endogenous metabolism and of exogenous chemicals, in order to enhance their elimination. They regulate numerous genes which are involved in drug and xenobiotic metabolism, including Phase I (cytochrome P450), Phase II (conjugation catalyzed by sulfotransferases, glucuronosyltransferases and glutathione S-transferases), and transporters (multidrug resistance proteins, multidrug resistance-associated proteins, and organic anion-transporting polypeptides). Although CAR and PXR were initially characterized as xenosensors, it is now evident that CAR and PXR also trigger pleiotropic effects on physiological or pathological functions. Recent studies have shown that the activation of CAR and PXR alters lipid metabolism, glucose homeostasis, and inflammation. Therefore, in addition to regulating drug elimination pathways, they also play important roles in regulating metabolic pathways. As a result, these receptors may be closely associated with the pathogenesis of many diseases. However, the pathophysiological roles of CAR and PXR are not fully understood. The purpose of this review is to discuss the physiological and pathological roles of CAR and PXR in liver diseases.

The role of the nuclear receptor constitutive androstane receptor in the pathogenesis of non-alcoholic steatohepatitis

BACKGROUND

Non-alcoholic fatty liver disease is a common liver injury, but the pathophysiological mechanisms leading to the development of non-alcoholic steatohepatitis (NASH) remain unclear. The pathological roles of the nuclear receptor constitutive androstane receptor (CAR), a key regulator of drug-metabolising enzymes, in the development of NASH were investigated.

METHODS AND RESULTS

CAR(+/+) and CAR(-/-) mice were given a methionine and choline-deficient (MCD) diet to establish a dietary model of NASH. Increases in serum alanine aminotransferase (ALT) and in infiltration of inflammatory cells were dominant in CAR(+/+) mice at 8 weeks. There was no significant difference in the lipid concentration of the liver - namely, the first hit between CAR(+/+) and CAR(-/-) mice. The index of lipid peroxidation increased in liver of the CAR(+/+) mice, as demonstrated by 8-iso-prostaglandin F2alpha (F2-isoprostanes). Western blotting analysis showed that nuclear translocation of CAR occurred in CAR(+/+) mice fed the MCD diet. As a result, the CAR activation caused the lipid peroxidation - namely, the second hit. The expressions of cytochrome P450 (CYP)2B10, 2C29, 3A11 all increased considerably in the CAR(+/+) mice. Furthermore, alpha smooth muscle actin immunohistochemistry and Sirius red staining showed an increase in the degree of fibrosis in CAR(+/+) mice fed the MCD diet at 16 weeks. The mRNA expressions of collagen alpha1(1) and the tissue inhibitor of metalloproteinase-1 were found to be elevated in CAR(+/+) mice.

CONCLUSION

CAR caused the worsening of the hepatic injury and fibrosis in the dietary model of NASH. Our results suggest that the CAR nuclear receptor may thus play a critical role in the pathogenesis of NASH.

Phenobarbital induction of drug/steroid-metabolizing enzymes and nuclear receptor CAR

Phenobarbital (PB) increases hepatic drug/steroid-metabolic capability by coordinately activating transcription of the genes encoding various metabolizing enzymes. The nuclear receptor CAR was first implicated as a transcription factor that activates the cytochrome P450 Cyp2b10 gene. In response to PB, CAR forms a heterodimer with the retinoid X receptor (RXR), binds to a PB response element (typified by DR-4 motif), and activates transcription of the gene. In the CAR-null mouse, PB does not only induce the Cyp2b10 gene, but also induces genes encoding various metabolizing enzymes. Thus, CAR is a general nuclear receptor that is essential for PB induction of drug/steroid metabolizing enzymes. PB also induces amino levulinate synthase 1 (ALAS-1), the rate-limiting enzyme in heme biosynthesis, to increase heme supply. However, PB induction of the synthase occurs in CAR-null mice, suggesting that CAR does not coordinate the heme synthesis for the induction of drug/steroid metabolism.

Primary liver cancers with nonalcoholic steatohepatitis

Nine patients with hepatocellular carcinoma (HCC) in nonalcoholic steatohepatitis (NASH) (six men and three women, median age 71.5 years) and one patient with intrahepatic cholangiocarcinoma (ICC), a 50-year-old man, in NASH are described. Most patients were associated with obesity, diabetes, hypertension, hypercholesterolemia, or hypertriglyceridemia. Seven patients showed insulin resistance and hyperinsulinemia. All patients except one met the criteria for metabolic syndrome. An HCC or ICC diagnosis was confirmed by tumor biopsy, surgery or autopsy except in two patients, who were diagnosed by computed tomography or hepatic angiography. The underlying liver disease was liver cirrhosis in six patients and chronic liver disease including mild hepatic fibrosis in four patients. The treatment of liver cancers consisted of surgery, radio-frequency ablation (RFA), transcatheter arterial embolization and transcatheter arterial infusion. Although the follow-up period was relatively short (median 27.5 months, average 32.1 months), all postoperative and post-RFA patients have not had a recurrence of HCC to date, except for one patient who had a palliative operation with intra-arterial infusion of anticancer drugs through an implanted reservoir port. Older age and liver cirrhosis are considered risk factors for HCC in NASH, and regular screening of these patients is necessary. Diabetes may contribute to the development of ICC in NASH. Curative therapy (surgery or RFA) and weight loss by the active therapeutic intervention (nutritional care and exercise therapy) after curative therapy may help us improve the prognosis of HCC in NASH.

HLA antigens in patients with interferon-alpha-induced autoimmune thyroid disorders in chronic hepatitis C

BACKGROUND/AIMS

To determine the immunological predisposition to autoimmune thyroid disorders induced by interferon-alpha therapy, human leukocyte antigen (HLA) was analyzed in patients with chronic hepatitis C who developed autoimmune thyroid disorders during or after treatment with interferon-alpha.

METHODS

Four hundred and thirty-nine patients with chronic hepatitis C (278 males and 161 females, aged 20-73 years) were treated with interferon-alpha (natural-alpha, 169; alpha-2a, 82; alpha-2b, 188) for 24 weeks.

RESULTS

Seventeen of 439 (3.9%) patients developed symptomatic autoimmune thyroid disorders; these included nine cases of hyperthyroidism and eight cases of hypothyroidism. The incidence of HLA-A2, B46 and Cw7 increased in patients with interferon-alpha-induced autoimmune thyroid disorders. Especially, the incidence of HLA-A2 (15/17; 88.2%) was significantly higher than that observed in the general population in Japan (corrected p-value (p(c)): p(c)<0.003). The odds ratios for the relative risk of the autoimmune thyroid disorders were A2, 10.6 [95% confidence interval, 2.4-46.5]; B46, 4.8 [1.6-14.0]; and Cw7, 3.0 [1.1-7.9].

CONCLUSIONS

Our study revealed that HLA-A2 is highly linked to the autoimmune thyroid disorders induced by interferon-alpha-therapy in patients with chronic hepatitis C.

Clinical features and treatment of nonalcoholic fatty liver disease across the Asia Pacific region-the GO ASIA initiative

BACKGROUND

The Gut and Obesity Asia (GO ASIA) workgroup was formed to study the relationships between obesity and gastrointestinal diseases in the Asia Pacific region.

AIM

To study factors associated with nonalcoholic steatohepatitis (NASH) and advanced fibrosis, and medical treatment of biopsy-proven nonalcoholic fatty liver disease (NAFLD) patients.

METHODS

Retrospective study of biopsy-proven NAFLD patients from centres in the GO ASIA Workgroup. Independent factors associated with NASH and with advanced fibrosis on binary logistic regression analyses in a training cohort were used for the development of their corresponding risk score, which were validated in a validation cohort.

RESULTS

We included 1008 patients from nine centres across eight countries (NASH 62.9%, advanced fibrosis 17.2%). Independent predictors of NASH were body mass index ≥30 kg/m² , diabetes mellitus, dyslipidaemia, alanine aminotransferase ≥88 U/L and aspartate aminotransferase ≥38 U/L, constituting the Asia Pacific NASH risk score. A high score has a positive predictive value of 80%-83% for NASH. Independent predictors of advanced fibrosis were age ≥55 years, diabetes mellitus and platelet count <150 × 10⁹ /L, constituting the Asia-Pacific NAFLD advanced fibrosis risk score. A low score has a negative predictive value of 95%-96% for advanced fibrosis. Only 1.7% of patients were referred for structured lifestyle program, 4.2% were on vitamin E, and 2.4% were on pioglitazone.

CONCLUSIONS

More severe liver disease can be suspected or ruled out based on factors identified in this study. Utilisation of structured lifestyle program, vitamin E and pioglitazone was limited despite this being a cohort of biopsy-proven NAFLD patients with majority of patients having NASH.

Preventive effects of vitamin K on recurrent disease in patients with hepatocellular carcinoma arising from hepatitis C viral infection

BACKGROUND

Despite the progression of therapeutic approaches, a high frequency of recurrence is what determines the long-term prognosis of patients with hepatocellular carcinoma (HCC). In this study, the chemopreventive effects of vitamin K2 on the recurrence and survival of patients with HCC after curative therapy were evaluated.

METHODS

Sixty patients who were diagnosed to be free of HCC after radiofrequency ablation therapy or surgery were randomly assigned to either the vitamin K2 group (n = 30 patients) or the control group (n = 30 patients). All patients were positive for the hepatitis C virus (HCV) antibody and hepatitis B surface antigen positive patients were excluded from this study. Patients in the vitamin K2 group received an oral dose of menatetrenone at 45 mg per day. Disease recurrence and the survival rates were analyzed in patients with HCC.

RESULTS

The cumulative recurrence-free rates in the vitamin K2 group were 92.3% at 12 months, 48.6% at 24 months and 38.8% at 36 months; and those in the control group were 71.7%, 35.9% and 9.9%, respectively (P = 0.045). The cumulative survival rates in the vitamin K2 group were 100% at 12 months, 95.0% at 24 months and 77.5% at 36 months; and those in the control group were 95.8%, 90.2% and 66.4%, respectively (P = 0.70).

CONCLUSIONS

Vitamin K2 may have a suppressive effect on the recurrence of HCC and a beneficial effect on tumor recurrence. However, there was no significant difference in the survival rates. The chemopreventive effects of vitamin K2 are not sufficient. The development of a further regimen such as combination therapy is required.

Stricture after endoscopic submucosal dissection for early gastric cancers and adenomas

BACKGROUND AND AIM

 Stricture is a complication that may occur after endoscopic submucosal dissection (ESD) of gastric neoplasms. The goal of the present study was to investigate the incidence, risk factors and management of gastric stricture after ESD.

METHODS

The medical records of 308 patients who underwent ESD for gastric neoplasms were reviewed. Stricture is defined as having symptoms caused by an obstruction through which a 1-cm diameter endoscopic fiber cannot be passed.

RESULTS

Stricture was identified in six of 308 patients (1.9%). Three of the six lesions were located in the prepylorus, two cases in the antrum and one in the cardia. The mean longitudinal distance and the mean area of the resected specimens in the six cases with stricture (7.8 ± 2.0 cm, 34.0 ± 15.8cm(2) , respectively) was significantly larger than in those without stricture (4.5 ± 1.4cm, 12.7 ± 8.3cm(2) , respectively, P<0.01). The ratio of the resected circumference/whole circumference was 83.3±7.5% in those with stricture in comparison to 25.4 ± 16.3% in those without stricture (P<0.01). All six patients underwent endoscopic balloon dilations, and obtained relief from stricture. However, one patient experienced a gastric perforation and recovered following conservative therapy.

CONCLUSION

 Sub-circumferential resection over 75% of the circumference by ESD in the prepylorus, antrum and cardia is a risk factor for the occurrence of stricture. Early intervention might be considered for this high-risk group to avoid a perforation during balloon dilation.

A global research priority agenda to advance public health responses to fatty liver disease

BACKGROUND & AIMS

An estimated 38% of adults worldwide have non-alcoholic fatty liver disease (NAFLD). From individual impacts to widespread public health and economic consequences, the implications of this disease are profound. This study aimed to develop an aligned, prioritised fatty liver disease research agenda for the global health community.

METHODS

Nine co-chairs drafted initial research priorities, subsequently reviewed by 40 core authors and debated during a three-day in-person meeting. Following a Delphi methodology, over two rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the priorities, via Qualtrics XM, indicating agreement using a four-point Likert-scale and providing written feedback. The core group revised the draft priorities between rounds. In R2, panellists also ranked the priorities within six domains: epidemiology, models of care, treatment and care, education and awareness, patient and community perspectives, and leadership and public health policy.

RESULTS

The consensus-built fatty liver disease research agenda encompasses 28 priorities. The mean percentage of 'agree' responses increased from 78.3 in R1 to 81.1 in R2. Five priorities received unanimous combined agreement ('agree' + 'somewhat agree'); the remaining 23 priorities had >90% combined agreement. While all but one of the priorities exhibited at least a super-majority of agreement (>66.7% 'agree'), 13 priorities had <80% 'agree', with greater reliance on 'somewhat agree' to achieve >90% combined agreement.

CONCLUSIONS

Adopting this multidisciplinary consensus-built research priorities agenda can deliver a step-change in addressing fatty liver disease, mitigating against its individual and societal harms and proactively altering its natural history through prevention, identification, treatment, and care. This agenda should catalyse the global health community's efforts to advance and accelerate responses to this widespread and fast-growing public health threat.

IMPACT AND IMPLICATIONS

An estimated 38% of adults and 13% of children and adolescents worldwide have fatty liver disease, making it the most prevalent liver disease in history. Despite substantial scientific progress in the past three decades, the burden continues to grow, with an urgent need to advance understanding of how to prevent, manage, and treat the disease. Through a global consensus process, a multidisciplinary group agreed on 28 research priorities covering a broad range of themes, from disease burden, treatment, and health system responses to awareness and policy. The findings have relevance for clinical and non-clinical researchers as well as funders working on fatty liver disease and non-communicable diseases more broadly, setting out a prioritised, ranked research agenda for turning the tide on this fast-growing public health threat.

Iron enhances hepatitis C virus replication in cultured human hepatocytes

BACKGROUND

Iron overload in the presence of increasing concentrations of iron is one of the indicators of poor response to interferon therapy in chronic hepatitis C. In order to analyze the effect of iron on hepatitis C virus (HCV) replication, we measured replication in an HCV-infected cell line.

METHODS AND RESULTS

Cells from a non-neoplastic HCV-infected human hepatocyte line (PH5CH8) susceptible to HCV infection and supportive of HCV replication were used in this study. The replication of HCV RNA was measured by reverse transcription-nested polymerase chain reaction (RT-nested PCR). PH5CH8 cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. PH5CH8 cells were incubated with 0, 1, 10, 50, and 100 microM of FeSO4 at 37 degrees C with 5% CO2. Forty-eight hours after iron supplementation, the quantity of HCV RNA in the cells incubated in 50 and 100 microM of FeSO4 was approximately ten times that of the cells with no iron supplementation. Similar changes were observed beginning at 12 h from supplementation with FeSO4 and continued for at least 72 h after supplementation. MTT assay indicated that iron did not have cytotoxic effects on the PH5CH8 cells.

CONCLUSION

Iron enhances HCV replication in a hepatocyte cell line. The results suggest that iron deposition in hepatocytes could facilitate HCV infection in the liver.