Meta-analysis of the diagnostic accuracy of serum type IV collagen 7S concentration for the staging of liver fibrosis in nonalcoholic fatty liver disease.

AIM: We aimed to evaluate the diagnostic accuracy of the measurement of serum type IV collagen 7S (T4C7S) concentration for the staging of liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: A systematic search or published works was carried out using the PubMed, Cochrane Library, and Web of Science Core Collection databases for studies of the accuracy of serum T4C7S concentration for the staging of fibrosis using Fibrosis stage (F)0-4 in patients with NAFLD diagnosed by liver biopsy. RESULTS: Nine articles describing 1475 participants with NAFLD were included. For fibrosis ≥F1, with n = 849, summary estimates of sensitivity of 0.79, specificity of 0.69, and area under the curve (AUC) of 0.80 were obtained using a median T7C4S cut-off value of 4.6 ng/ml. For fibrosis ≥F2, with n = 1,090, summary estimates of sensitivity of 0.78, specificity of 0.78, and AUC of 0.84 were obtained using a median cut-off value of 4.9 ng/ml. For fibrosis ≥F3, with n = 1311 participants and a median cut-off value of 5.4 ng/ml, a pooled sensitivity of 0.82, specificity of 0.81, and AUC of 0.83 were obtained. For fibrosis ≥F4, with n = 753 and a median cut-off value of 6.6 ng/ml, a pooled sensitivity of 0.85, specificity of 0.81, and AUC of 0.85 were obtained. CONCLUSIONS: Serum T4C7S concentration was found to be an accurate method of staging liver fibrosis in patients with NAFLD.

MRI-Based Quantitative R2* Mapping at 3 Tesla Reflects Hepatic Iron Overload and Pathogenesis in Nonalcoholic Fatty Liver Disease Patients.

BACKGROUND: The role of hepatic iron overload (HIO) in nonalcoholic fatty liver disease (NAFLD) pathogenesis has not been fully elucidated. PURPOSE: This study aimed to investigate the effect of HIO and examine the diagnostic usefulness of magnetic resonance imaging (MRI)-based R2* quantification in evaluating hepatic iron content (HIC) and pathological findings in NAFLD. STUDY TYPE: Prospective and retrospective. POPULATION: A prospective study of 168 patients (age, 57.2 ± 15.0; male/female, 80/88) and a retrospective validation study of 202 patients (age, 57.0 ± 14.4; male/female, 113/89) with liver-biopsy-confirmed NAFLD were performed. FIELD STRENGTH/SEQUENCE: 3 T; chemical-shift encoded multi-echo gradient echo. ASSESSMENT: Using liver tissues obtained by liver biopsy, HIC was prospectively evaluated in 168 patients by atomic absorption spectrometry. Diagnostic accuracies of HIC and R2* for grading hepatic inflammation plus ballooning (HIB) as an indicator of NAFLD activity were assessed. STATISTICAL TESTS: Student's t-test and analysis of variance (ANOVA) with Scheffe's multiple testing correction for univariate comparisons; multivariate logistic analysis. P-value less than 0.05 is statistically significant. RESULTS: HIC was significantly correlated with HIB grades (r = 0.407). R2* was significantly correlated with HIC (r = 0.557) and HIB grades (r = 0.569). R2* mapped an area under the receiver operating characteristic (AUROC; 0.774) for HIC ≥808 ng/mL (median value) with cutoff value of 62.5 s-1 . In addition, R2* mapped AUROC of HIB for grades ≥3 was 0.799 with cutoff value of 58.5 s-1 . When R2* was <62.5 s-1 , R2* correlated weakly with HIC (r = 0.372) as it was affected by fat deposition and did not correlate with HIB grades (P = 0.052). Conversely, when R2* was ≥62.5 s-1 , a significant correlation of R2* with HIC (r = 0.556) and with HIB grades was observed (P < 0.0001) with being less affected by fat deposition. DATA CONCLUSION: R2* ≥ 62.5 s-1 is a promising modality for non-invasive diagnosis of clinically important high grades (≥3) of HIB associated with increased HIC. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 2.

Protective effect of SGL5213, a potent intestinal sodium-glucose cotransporter 1 inhibitor, in nonalcoholic fatty liver disease in mice.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic disease. SGL5213, which is minimally absorbed and is restricted to the intestinal tract, is a potent intestinal sodium-glucose cotransporter 1 (SGLT1) inhibitor. In this study, we investigated the protective effect of SGL5213 in a rodent model of NAFLD. METHODS: Using a rodent model of NAFLD, we compared SGL5213 efficacy with miglitol, which is an α-glucosidase inhibitor. We used a high-fat and high-sucrose diet-induced NAFLD model. RESULTS: SGL5213 and miglitol improved obesity, liver dysfunction, insulin resistance, and the NAFLD severity. To further investigate the effects of SGL5213, we analyzed the mRNA expression of genes involved in lipid metabolism, inflammation, and liver fibrosis, and cecal pH levels. SGL5213 and miglitol treatment significantly decreased mRNA expression of factors involved in inflammation and liver fibrosis. SGL5213 treatment significantly decreased cecal pH levels, which did not occur with miglitol. CONCLUSIONS: SGL5213 had a protective effect on the pathogenesis of NAFLD in a rodent model. We considered that inhibiting glucose absorption and increasing glucose content in the gastrointestinal tract with SGL5213 might have contributed to the protective effect in NAFLD. SGL5213 is a promising therapeutic agent for NAFLD with obesity and insulin resistance.

Complications of Non-Alcoholic Fatty Liver Disease in Extrahepatic Organs.

Non-alcoholic fatty liver disease (NAFLD) is now recognized as the most common chronic liver disease worldwide, along with the concurrent epidemics of metabolic syndrome and obesity. Patients with NAFLD have increased risks of end-stage liver disease, hepatocellular carcinoma, and liver-related mortality. However, the largest cause of death among patients with NAFLD is cardiovascular disease followed by extrahepatic malignancies, whereas liver-related mortality is only the third cause of death. Extrahepatic complications of NAFLD include chronic kidney disease, extrahepatic malignancies (such as colorectal cancer), psychological dysfunction, gastroesophageal reflux disease, obstructive sleep apnea syndrome, periodontitis, hypothyroidism, growth hormone deficiency, and polycystic ovarian syndrome. The objective of this narrative review was to summarize recent evidences about extrahepatic complications of NAFLD, with focus on the prevalent/incident risk of such diseases in patients with NAFLD. To date, an appropriate screening method for extrahepatic complications has not yet been determined. Collaborative care with respective experts seems to be necessary for patient management because extrahepatic complications can occur across multiple organs. Further studies are needed to reveal risk profiles at baseline and to determine an appropriate screening method for extrahepatic diseases.

Lubiprostone in patients with non-alcoholic fatty liver disease: a randomised, double-blind, placebo-controlled, phase 2a trial.

BACKGROUND: The laxative drug lubiprostone improves intestinal permeability in healthy volunteers. We aimed to assess efficacy and safety of lubiprostone in patients with non-alcoholic fatty liver disease (NAFLD) with constipation via attenuation of intestinal permeability. METHODS: This randomised, double-blind, placebo-controlled, phase 2a study in Yokohama City University Hospital, Japan, recruited patients (aged 20-85 years) with NAFLD and constipation, alanine aminotransferase (ALT) at least 40 U/L, liver stiffness (≤6·7 kPa), and hepatic fat fraction at least 5·2% when assessed by MRI-proton density fat fraction. Eligible patients were randomly assigned (11:10:9) by a computer-based system and stratified by age and sex to receive 24 µg lubiprostone, 12 µg lubiprostone, or placebo, orally, once per day for 12 weeks. The primary endpoint was the absolute changes in ALT at 12 weeks. Efficacy analysis was done by intention to treat. Safety was assessed in all treated patients. This trial was registered with University Hospital Medical Information Network Clinical Trials Registry (UMIN000026635). FINDINGS: Between March 24, 2017, and April 3, 2018, we screened 288 patients, of whom 150 (52%) were randomly assigned to treatment: 55 patients were assigned to receive 24 µg lubiprostone, 50 to receive 12 µg lubiprostone, and 45 to receive placebo. A greater decrease in the absolute ALT levels from baseline to 12 weeks was seen in the 24 µg lubiprostone group (mean -13 U/L [SD 19]) than in the placebo group (1 U/L [24]; mean difference -15 U/L [95% CI -23 to -6], p=0·0007) and in the 12 µg lubiprostone group (-12 U/L [21]) than in the placebo group (mean difference -13 U/L [-22 to -5], p=0·0023). 18 (33%) of 55 patients in the 24 µg group had at least one adverse event, as did three (6%) of 47 patients in the 12 µg group and three (7%) of 43 in the placebo group. The most common adverse event was diarrhoea (17 [31%] of patients in the 24 µg group, three [6%] in the 12 µg group, none in the placebo group). No life-threatening events or treatment-related deaths occurred. INTERPRETATION: Lubiprostone was well tolerated and reduced the levels of liver enzymes in patients with NAFLD and constipation. Further studies are necessary to better define the efficacy and tolerability of lubiprostone in patients with NAFLD without constipation. FUNDING: Mylan EPD G.K.

Metabolomic/lipidomic-based analysis of plasma to diagnose hepatocellular ballooning in patients with non-alcoholic fatty liver disease: A multicenter study.

AIM: Liver biopsy is still required for the diagnosis of hepatocellular ballooning and inflammation, which are important histological features of non-alcoholic steatohepatitis. We undertook this multicenter, cross-sectional study to identify novel blood markers for the diagnosis of hepatocellular ballooning. METHODS: We enrolled 176 patients, of whom 132 were proven by liver biopsy as having non-alcoholic fatty liver disease (NAFLD) and classified as non-ballooning (ballooning grade 0) (n = 83) or ballooning (ballooning grade 1 and 2) (n = 49) by a central pathology review. We carried out gas chromatography-mass spectrometry, hydrophilic interaction liquid chromatography tandem mass spectrometry, and lipidomics with plasma. RESULTS: As correlates of hepatocellular ballooning, among the clinical parameters, serum type IV collagen 7S correlated most significantly with the ballooning grade (correlation coefficient [CC] = 0.463; P < 0.001). Among the metabolic/lipidomic markers, phosphatidylcholine (PC) (aa-44:8) correlated most significantly with the ballooning grade (CC = 0.394; P < 0.001). The area under the receiver operating characteristic curve of type IV collagen 7S, choline, and lysophosphatidylethanolamine (LPE) (e-18:2), was 0.846 (95% confidence interval, 0.772-0.919). CONCLUSIONS: Plasma levels of PC were positively correlated, and those of lysophosphatidylcholine and LPE were negatively correlated with hepatocellular ballooning in NAFLD patients. These non-invasive metabolic/lipidomic-based plasma tests might be useful to distinguish between cases of NAFLD with and without hepatocellular ballooning.

Autotaxin is a valuable biomarker for the prediction of liver fibrosis in patients with non-alcoholic fatty liver disease.

AIM: We investigated the characteristics of serum autotaxin (ATX) and its diagnostic performance for liver fibrosis in a large cohort of patients with non-alcoholic fatty liver disease (NAFLD). METHODS: We compared the usefulness of ATX and other fibrosis markers in 307 biopsy-confirmed NAFLD patients. In addition, in 145 participants with NAFLD, we compared the diagnostic performance of ATX with that of non-invasive imaging methods (vibration-controlled transient elastography and magnetic resonance elastography [MRE]). RESULTS: Serum ATX concentration was significantly correlated with fibrosis stage in male and female NAFLD patients. In male patients, the area under the receiver operating characteristic (AUROC) curve values of ATX for the diagnosis of ≥stage 1, ≥stage 2, ≥stage 3, and ≥stage 4 fibrosis were 0.65, 0.75, 0.81, and 0.95, respectively. In female NAFLD participants, the AUROC values were all >0.81. The sensitivity of ATX was highest for the diagnosis of ≥stage 2 and ≥stage 3 fibrosis in both men and women with NAFLD. In the comparison between ATX and non-invasive imaging methods, the AUROC for MRE was the highest at every stage of fibrosis. CONCLUSIONS: Serum ATX concentration is significantly correlated with fibrosis stage in NAFLD patients. The diagnostic accuracy of ATX for liver fibrosis is lower than that of MRE, but the sensitivities of ATX for the diagnosis of ≥stage 2 and ≥stage 3 were highest. We conclude that ATX is useful for the selection of patients requiring further evaluation for liver fibrosis.

Assessment of 10-year changes in liver stiffness using vibration-controlled transient elastography in non-alcoholic fatty liver disease.

AIM: Although liver biopsy is the gold standard for the diagnosis and staging of non-alcoholic fatty liver disease (NAFLD), repeated assessment of patients' liver tissue conditions are impractical. We assessed the 10-year changes in liver stiffness measurements (LSM) utilizing vibration-controlled transient elastography in NAFLD patients. METHODS: From January 2006 to September 2007, LSM was carried out for 97 biopsy-proven NAFLD patients. Of these, 34 patients underwent 10-year LSM reassessments (14 of them with paired biopsies). RESULTS: We evaluated the changes in the fibrosis stage as estimated using LSM (FS-LSM). Over a 10-year period, 32.4% had FS-LSM progression, 50% had static disease, and 17.6% had FS-LSM improvement. From among the initially diagnosed non-alcoholic steatohepatitis patients, 18% had progressed to considerable stage 4 (cirrhosis) 10 years later. In this cohort, none of the patients who had been initially diagnosed as FS-LSM stage 0 had progressed to cirrhosis 10 years later. The changes in LSM were correlated with the change in the histological fibrosis stage, the NAFLD activity score, and the change in the sum of the steatosis, activity, and fibrosis score. Improving more than 1 body mass index (kg/m2 ) and having a higher initial aspartate aminotransferase, alanine aminotransferase (ALT), or ALT responder (>30% improvement or reduction to less than 40 IU/L) were factors contributing to LSM improvements (≥2 kPa). CONCLUSIONS: Vibration-controlled transient elastography is likely to become a more clinically important tool for the long-term monitoring of NAFLD patients.

Distribution of liver stiffness in non-alcoholic fatty liver disease with higher fibrosis-4 index than low cut-off index.

BACKGROUND AND AIM: In the condition of high prevalence of non-alcoholic fatty liver disease (NAFLD), a new diagnostic algorithm to efficiently identify NAFLD patients with significant fibrosis is urgently required. We evaluated the predictive ability of the fibrosis-4 index (FIB-4 index) for significant liver fibrosis (F ≥ 2) in a cohort of Japanese patients with NAFLD. METHODS: We prospectively calculated the FIB-4 index in patients who were incidentally diagnosed as fatty liver in medical checkups and then conducted liver stiffness measurement by vibration-controlled transient elastography (VCTE) only in patients in whom the FIB-4 index was more than the low cut-off index (> 1.45). RESULTS: Of the 5929 people who underwent medical checkups, a total of 1374 people were identified as having fatty liver. Among these, we performed VCTE in 106 patients in whom the FIB-4 index was higher than 1.45. The distribution of the fibrosis stage as estimated by VCTE in the patients was as follows: F0, 52.8%; F1, 10.3%; F2, 21.6%; F3, 11.3%; and F4, 3.7%. The positive predictive value of the FIB-4 index for detecting NAFLD with significant fibrosis was 36.6%. The minimum value of the FIB-4 index was constant for each estimated fibrosis stage. CONCLUSIONS: This is the first prospective study to evaluate the usefulness of the FIB-4 index as the first step to screen NAFLD patients with significant fibrosis. In Japan, addition of one further step that combined with the FIB-4 index is necessary to meaningfully reduce the number of patients needing liver stiffness measurement or liver biopsy.

Identification of differentially methylated region (DMR) networks associated with progression of nonalcoholic fatty liver disease.

The progression of nonalcoholic fatty liver disease (NAFLD) is affected by epigenetics. We performed differentially methylated region (DMR) and co-methylation analyses to identify DMR networks associated with the progression of NAFLD. DMRs displaying differences in multiple consecutive differentially methylated CpGs between mild and advanced NAFLD were extracted. The average values of topological overlap measures for the CpG matrix combining two different DMRs were calculated and two DMR networks that strongly correlated with the stages of fibrosis were identified. The annotated genes of one network included genes involved in transcriptional regulation, cytoskeleton organization, and cellular proliferation. The annotated genes of the second network were primarily associated with metabolic pathways. The CpG methylation levels in these networks were strongly affected by age and fasting plasma glucose levels, which may be important co-regulatory factors. The methylation status of five DMRs in the second network was reversible following weight loss. Our results suggest that CpG methylation in DMR networks is regulated concomitantly via aging and hyperglycemia and plays important roles in hepatic metabolic dysfunction, fibrosis, and potential tumorigenesis, which occur during the progression of NAFLD. By controlling weight and blood glucose levels, the methylation of DMRs in the second network may be reduced.

Palmitate-induced lipotoxicity is crucial for the pathogenesis of nonalcoholic fatty liver disease in cooperation with gut-derived endotoxin.

Although previous studies have indicated important roles of palmitate, a saturated fatty acid, in the pathogenesis of nonalcoholic fatty liver disease (NAFLD), it remains unclear how palmitate contributes to inflammation and fibrosis in the liver. Administration of palmitate in high fat diet (HFD)-fed but not basal diet (BD)-fed mice resulted in an increase in serum alanine aminotransferase (ALT) levels. Surprisingly, combined administration of very low dose lipopolysaccharide in palmitate-treated mice led to a marked increase in serum ALT levels despite BD-fed conditions. Administration of palmitate alone in BD-fed mice caused inflammatory cell infiltration and liver fibrosis mediated by the toll-like receptor 4 pathway without ALT elevation. In addition, a significant correlation between serum free fatty acid levels and liver fibrosis stage was observed in patients with NAFLD. These results indicate that palmitate may play crucial roles in the pathogenesis of NAFLD in the presence of gut-derived endotoxin.

New microwave ablation system for unresectable liver tumors that forms large, spherical ablation zones.

BACKGROUND AND AIM: The aim of this study was to assess the efficacy of a new microwave ablation (MWA) system, the Emprint Ablation System, for the ablation of unresectable large liver tumors (≥ 30 mm). METHODS: Twenty-one hepatic tumors (mean diameter, 34.7 mm) from 21 patients who underwent percutaneous MWA were included in this cross-sectional study. A volume analyzer based on computed tomography imaging was used for all patients within the month before and month after the procedure to evaluate the shape and volume of ablation zones. In addition, computed tomography imaging was performed again 3 months after the procedure to evaluate the presence of residual tumors and local recurrence. RESULTS: Mean ablation time was 11.3 min, and mean overall procedure time was 33.4 min. An ablated adrenal gland-induced Takotsubo (stress) cardiomyopathy occurred immediately after MWA as a major complication in one patient. Roundness index A, B, and C presented a mean value of 0.94, 0.94, and 1.01, respectively (all values near 1 is a perfect sphere), indicating that a spherical ablation zone was achieved. The mean ablation volume was larger than the volume of tumors (24.5 vs 41.7 cm3 ). Residual tumors were confirmed in only 4.8% of tumors after a single ablation session. There was no local recurrence. CONCLUSIONS: In our experience, the new MWA system provides an effective treatment option for unresectable large liver tumors. However, to ablate the liver tumors safely, it is necessary to consider the surrounding organs, such as the adrenal glands.

Magnetic resonance elastography increases usefulness and safety of non-invasive screening for esophageal varices.

BACKGROUND AND AIMS: The Baveno VI criteria enable non-invasive screening for esophageal varices. However, these criteria were established based on studies examining a large proportion of patients with viral hepatitis and relatively few patients with non-alcoholic fatty liver disease (NAFLD). Furthermore, because vibration-controlled transient elastography (VCTE) has a high incidence of measurement error, improved criteria are needed. We aimed to develop criteria based on magnetic resonance elastography (MRE) even among patients with NAFLD. METHODS: We performed a cross-sectional analysis of patients who had undergone MRE and/or VCTE as well as an esophagogastroduodenoscopy. The patients were classified as having either a low risk or a high risk of varices. The optimal cut-offs for ruling out esophageal varices were calculated for the MRE and VCTE liver stiffness measurement (LSM), the platelet count in an estimation cohort, and the cut-offs were then evaluated using validation cohorts composed of patients who had undergone only MRE or VCTE. RESULTS: The study included 627 patients (39% with NAFLD). The optimal cut-off values for the MRE-LSM and the platelet count were 4.2 kPa and 18.0 × 104 /µL, respectively. An MRE-LSM of 4.2 kPa plus a platelet count of 18.0 × 104 /µL had a negative predictive value of 1.00 for both low-risk plus high-risk varices as well as for high-risk varices in a validation cohort, enabling the presence of varices to be ruled out. CONCLUSIONS: Magnetic resonance elastography might enable a safer avoidance of screening endoscopy, with a smaller measurement error, among patient populations with a high prevalence of NAFLD.

Efficacy, safety, and tolerability of lubiprostone for the treatment of non-alcoholic fatty liver disease in adult patients with constipation: The LUBIPRONE, double-blind, randomised, placebo-controlled study design.

BACKGROUND: This paper reports the protocol of a randomised, double-blind, placebo-controlled study to test the efficacy, safety, and tolerability of lubiprostone (LUB) vs. placebo on suppressing gut permeability in non-alcoholic fatty liver disease (NAFLD) patients with constipation. NAFLD, including non-alcoholic steatohepatitis (NASH), is a common chronic liver disorder. Progression is associated with increased gut permeability and gut-derived endotoxins. Most NAFLD/NASH clinical trial drugs aim to improve liver function or systemic metabolism. LUB is a type 2 chloride channel activator used as a laxative for the treatment of patients with constipation. LUB suppresses gut permeability induced by non-steroidal anti-inflammatory drugs in healthy volunteers and lowers blood endotoxin levels. There have been no clinical studies of LUB for NAFLD/NASH patients. METHODS: The study plans to enrol adult patients (20-85 years, planned enrolment, n = 150; planned sample size, n = 120) with NAFLD and constipation, alanine aminotransferase ≥40 IU/L, equivalent steatosis grade ≥1, and equivalent fibrosis stage <4 measured using non-invasive vibration-controlled transient elastography and magnetic resonance imaging. Participants will be randomly allocated into three groups: LUB 12 µg, LUB 24 µg, and a placebo group. RESULTS: The primary endpoint will be changes in alanine aminotransferase from baseline at 12 weeks. The main secondary endpoint will be changes in intestinal permeability from baseline at 12 weeks using the lactulose mannitol ratio. CONCLUSIONS: This study will determine whether LUB improves gut permeability in NAFLD patients with constipation. TRIAL REGISTRATION: This trial is registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN000026635).

Wisteria floribunda agglutinin-positive Mac-2-binding protein and type 4 collagen 7S: useful markers for the diagnosis of significant fibrosis in patients with non-alcoholic fatty liver disease.

BACKGROUND AND AIM: The fibrosis stage of liver is associated with the long-term outcomes in patients with non-alcoholic fatty liver disease (NAFLD). However, significant fibrosis, defined as fibrosis stages 2-4, is associated with an elevated risk of progression to severe liver disease; there have been scant reports about diagnosing significant fibrosis. We compare the noninvasive method and aim to identify appropriate liver fibrosis markers for detecting significant fibrosis in NAFLD patients. METHODS: We compared the usefulness of liver fibrosis markers (Wisteria floribunda agglutinin-positive Mac-2-binding protein [WFA+ -M2BP], type 4 collagen 7S, etc.), clinical scoring systems, and liver stiffness measurement obtained using vibration-controlled transient elastography and magnetic resonance imaging-based magnetic resonance elastography in the same individuals and identified the most appropriate noninvasive method for detecting significant fibrosis in 165 patients with liver biopsy-diagnosed NAFLD. RESULTS: The area under the receiver operating characteristic curve based on the serum cutoff index values of WFA+ -M2BP/the serum levels of type IV collagen 7S for the diagnosis of significant fibrosis was 0.832 (95% confidence interval: 0.771-0.894)/0.837 (95% confidence interval: 0.778-0.898). "WFA+ -M2BP (cutoff index) ≥ 0.83 or type IV collagen 7S ≥ 5.2 ng/mL" showed a high sensitivity (91.4%) and negative predictive value (87.9%) for the diagnosis of significant fibrosis. CONCLUSIONS: We showed that serum WFA+ -M2BP or type IV collagen 7S levels serve as useful independent markers for detecting significant fibrosis and that use of both WFA+ -M2BP and type IV collagen 7S together increased the sensitivity and negative predictive value for the diagnosis of liver fibrosis. These results need to be validated in larger populations from multiple clinical centers.

Identification of the genomic region under epigenetic regulation during non-alcoholic fatty liver disease progression.

AIM: The progression of non-alcoholic fatty liver disease (NAFLD) is affected by epigenetics. We undertook co-methylation and differentially methylated region (DMR) analyses to identify the genomic region that is under epigenetic regulation during NAFLD progression. METHODS: We collected liver biopsy specimens from 60 Japanese patients with NAFLD and classified these into mild (fibrosis stages 0-2) or advanced (fibrosis stages 3-4) NAFLD. We carried out a genome-wide DNA methylation analysis and identified the differentially methylated CpGs between mild and advanced NAFLD. Differentially methylated regions with multiple consecutive differentially methylated CpGs between mild and advanced NAFLD were extracted. RESULTS: Co-methylation analysis showed that individual differentially methylated CpG sites were clustered into three modules. The CpG sites clustered in one module were hypomethylated in advanced NAFLD and their annotated genes were enriched for "immune system" function. The CpG sites in another module were hypermethylated and their annotated genes were enriched for "mitochondria" or "lipid particle", and "lipid metabolism" or "oxidoreductase activity". Hypomethylated DMRs included tumorigenesis-related genes (FGFR2, PTGFRN, and ZBTB38), the expressions of which are upregulated in advanced NAFLD. Tumor suppressor MGMT had two DMRs and was downregulated. Conversely, FBLIM1 and CYR61, encoding proteins that reduce cell proliferation, showed hypomethylated DMRs and were upregulated. Expression of the antioxidant gene NQO1 was upregulated, with a hypomethylated DMR. The DMR containing cancer-related MIR21 was hypomethylated in advanced NAFLD. CONCLUSIONS: Co-methylation and DMR analyses suggest that the NAFLD liver undergoes mitochondrial dysfunction, decreased lipid metabolism, and impaired oxidoreductase activity, and acquires tumorigenic potential at the epigenetic level.

Efficacy of glutathione for the treatment of nonalcoholic fatty liver disease: an open-label, single-arm, multicenter, pilot study.

BACKGROUND: Glutathione plays crucial roles in the detoxification and antioxidant systems of cells and has been used to treat acute poisoning and chronic liver diseases by intravenous injection. This is a first study examining the therapeutic effects of oral administration of glutathione in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: The study was an open label, single arm, multicenter, pilot trial. Thirty-four NAFLD patients diagnosed using ultrasonography were prospectively evaluated. All patients first underwent intervention to improve their lifestyle habits (diet and exercise) for 3 months, followed by treatment with glutathione (300 mg/day) for 4 months. We evaluated their clinical parameters before and after glutathione treatment. We also quantified liver fat and fibrosis using vibration-controlled transient elastography. The primary outcome of the study was the change in alanine aminotransferase (ALT) levels. RESULTS: Twenty-nine patients finished the protocol. ALT levels significantly decreased following treatment with glutathione for 4 months. In addition, triglycerides, non-esterified fatty acids, and ferritin levels also decreased with glutathione treatment. Following dichotomization of ALT responders based on a median 12.9% decrease from baseline, we found that ALT responders were younger in age and did not have severe diabetes compared with ALT non-responders. The controlled attenuation parameter also decreased in ALT responders. CONCLUSIONS: This pilot study demonstrates the potential therapeutic effects of oral administration of glutathione in practical dose for patients with NAFLD. Large-scale clinical trials are needed to verify its efficacy. TRIAL REGISTRATION: UMIN000011118 (date of registration: July 4, 2013).

Identification of core gene networks and hub genes associated with progression of non-alcoholic fatty liver disease by RNA sequencing.

AIM: Non-alcoholic fatty liver disease (NAFLD) progresses because of the interaction between numerous genes. Thus, we carried out a weighted gene coexpression network analysis to identify core gene networks and key genes associated with NAFLD progression. METHODS: We enrolled 39 patients with mild NAFLD (fibrosis stages 0-2) and 21 with advanced NAFLD (fibrosis stages 3-4). Total RNA was extracted from frozen liver biopsies, and sequenced to capture a large dynamic range of expression levels. RESULTS: A total of 1777 genes differentially expressed between mild and advanced NAFLD (q-value <0.05) clustered into four modules. One module was enriched for genes that encode cell surface or extracellular matrix proteins, and are involved in cell adhesion, proliferation, and signaling. This module formed a scale-free network containing four hub genes (PAPLN, LBH, DPYSL3, and JAG1) overexpressed in advanced NAFLD. PAPLN is a component of the extracellular matrix, LBH and DPYSL3 are reported to be tumor suppressors, and JAG1 is tumorigenic. Another module formed a random network, and was enriched for genes that accumulate in the mitochondria. These genes were downregulated in advanced NAFLD, reflecting impaired mitochondrial function. However, the other two modules did not form unambiguous networks. KEGG analysis indicated that 71 differentially expressed genes were involved in "pathways in cancer". Strikingly, expression of half of all differentially expressed genes was inversely correlated with methylation of CpG sites (q-value <0.05). Among clinical parameters, serum type IV collagen 7 s was most strongly associated with the epigenetic status in NAFLD. CONCLUSIONS: Newly identified core gene networks suggest that the NAFLD liver undergoes mitochondrial dysfunction and fibrosis, and acquires tumorigenic potential epigenetically. Our data provide novel insights into the pathology and etiology of NAFLD progression, and identify potential targets for diagnosis and treatment.

Pemafibrate, a novel selective peroxisome proliferator-activated receptor alpha modulator, improves the pathogenesis in a rodent model of nonalcoholic steatohepatitis.

The efficacy of peroxisome proliferator-activated receptor α-agonists (e.g., fibrates) against nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) in humans is not known. Pemafibrate is a novel selective peroxisome proliferator-activated receptor α modulator that can maximize the beneficial effects and minimize the adverse effects of fibrates used currently. In a phase-2 study, pemafibrate was shown to improve liver dysfunction in patients with dyslipidaemia. In the present study, we first investigated the effect of pemafibrate on rodent models of NASH. Pemafibrate efficacy was assessed in a diet-induced rodent model of NASH compared with fenofibrate. Pemafibrate and fenofibrate improved obesity, dyslipidaemia, liver dysfunction, and the pathological condition of NASH. Pemafibrate improved insulin resistance and increased energy expenditure significantly. To investigate the effects of pemafibrate, we analysed the gene expressions and protein levels involved in lipid metabolism. We also analysed uncoupling protein 3 (UCP3) expression. Pemafibrate stimulated lipid turnover and upregulated UCP3 expression in the liver. Levels of acyl-CoA oxidase 1 and UCP3 protein were increased by pemafibrate significantly. Pemafibrate can improve the pathogenesis of NASH by modulation of lipid turnover and energy metabolism in the liver. Pemafibrate is a promising therapeutic agent for NAFLD/NASH.

Resveratrol ameliorates fibrosis and inflammation in a mouse model of nonalcoholic steatohepatitis.

The natural polyphenol compound resveratrol (RSV) is considered to have a broad spectrum of beneficial biological activities upon human health. However, the exact effect of RSV on steatosis (a phenotype of non-alcoholic fatty liver [NAFL]) or fibrosis and inflammation (major phenotypes of non-alcoholic steatohepatitis [NASH]) is not known. Our data showed that administration of RSV (2 or 20 mg/kg/day) did not suppress steatosis in a high-fat diet-induced model of NAFL in mice. In contrast, identical concentrations of RSV dramatically inhibited inflammation and fibrosis in a low-dose lipopolysaccharide-induced model of NASH. These data suggested that RSV administration-mediated improvement of inflammation and fibrosis was due to the inhibition of LPS reactivity controlled by CD14 expression in Kupffer cells. These findings suggest that RSV could be a candidate agent for the treatment of NASH.