Hepatocyte-specific fibroblast growth factor 21 overexpression ameliorates high-fat diet-induced obesity and liver steatosis in mice.

Fibroblast growth factor (FGF) 21 is an endocrine growth factor mainly secreted by the liver in response to a ketogenic diet and alcohol consumption. FGF21 signaling requires co-receptor ß-klotho (KLB) co-acting with FGF receptors, which has pleiotropic metabolic effects, including induced hepatic fatty acid oxidation and ketogenesis, in human and animal models of obesity. We examined the hepatocyte-specific enhancer/promoter of FGF21 expression plasmids in high-fat diet-fed mice for 12 weeks. Hydrodynamic injection for FGF21 delivery every 6 weeks sustained high circulating levels of FGF21, resulting in marked reductions in body weight, epididymal fat mass, insulin resistance, and liver steatosis. FGF21-induced lipolysis in the adipose tissue enabled the liver to be flooded with fat-derived FFAs. The hepatic expression of Glut2 and Bdh1 was upregulated, whereas that of gluconeogenesis-related genes, G6p and Pepck, and lipogenesis-related genes, Srebp-1 and Srebp-2, was significantly suppressed. FGF21 induced the phosphorylation of AMPK at Thr172 and Raptor at ser792 and suppressed that of mTOR at ser2448, which downregulated mTORC1 signaling and reduced IRS-1 phosphorylation at ser1101. Finally, in the skeletal muscle, FGF21 increased Glut4 and Mct2, a membrane protein that acts as a carrier for ketone bodies. Enzymes for ketone body catabolism (Scot) and citrate cycle (Cs, Idh3a), and a marker of regenerating muscle (myogenin) were also upregulated via increased KLB expression. Thus, FGF21-induced lipolysis was continuously induced by a high-fat diet and fat-derived FFAs might cause liver damage. Hepatic fatty acid oxidation and ketone body synthesis may act as hepatic FFAs' disposal mechanisms and contribute to improved liver steatosis. Liver-derived ketone bodies might be used for energy in the skeletal muscle. The potential FGF21-related crosstalk between the liver and extraliver organs is a promising strategy to prevent and treat metabolic syndrome-related nonalcoholic steatohepatitis.

The Effect of Genetic Polymorphism in Response to Body Weight Reduction in Japanese Patients with Nonalcoholic Fatty Liver Disease.

BACKGROUND: weight loss as a result of lifestyle intervention is effective when treating non-alcoholic fatty liver disease (NAFLD). We estimated the effects of PNPLA3 rs738409 and HSD17B13 rs6834314 variants in response to diet therapy in Japanese patients with NAFLD. METHODS: we analyzed the correlation between the change in liver stiffness and change in body weight in 140 patients administered diet therapy for 1-year, according to PNPLA3 and HSD17B13 genotypes. RESULTS: the bodyweight (BW) reduction rate was greater in patients with the PNPLA3 genotype CC than CG and GG (p = 0.035). Change in liver stiffness measurement (LSM) was significantly associated with a change in BW in PNPLA3 CG/GG (r = 0.279/0.381), but not in PNPLA3 CC (p = 0.187). Change in LSM was correlated with change in BW only in patients with HSD17B13 AG/GG (r = 0.425), but not the AA genotype (p = 0.069). A multivariate analysis identified that a change in LSM was correlated with a change in BW in carriers of HSD17B13 AG/GG (B = 3.043, p = 0.032), but not HSD17B13 AA. The change in LSM of patients with a BW reduction of more than 7% (0.50) was significantly greater than that of patients with a BW reduction of less than 7% (0.83) (p = 0.038). CONCLUSIONS: in Japanese patients with NAFLD, HSD17B13 rs6834314 polymorphism is associated with the change in LSM by lifestyle intervention. The approach, including genetic assessments, may contribute to the establishment of appropriate therapeutic strategies to treat NAFLD.

PPARα agonist and metformin co-treatment ameliorates NASH in mice induced by a choline-deficient, amino acid-defined diet with 45% fat.

We explored the beneficial effects of GW7647, a peroxisome proliferator activated receptor α (PPARα) agonist, and metformin, an anti-diabetic drug on an advanced nonalcoholic steatohepatitis (NASH) model in rodents and investigated the possible mechanisms involved. Mice were fed control chow or a choline-deficient L-amino acid-defined diet containing 45% fat (HF-CDAA). The mice fed HF-CDAA diets for 16 weeks were divided into four groups: the no treatment (HF-CDAA), HF-CDAA containing 1000 mg/kg metformin, HF-CDAA containing 10 mg/kg GW7647, and HF-CDAA with both metformin and GW7647 groups. Metformin alone slightly deteriorated the aspartate and alanine aminotransferase (AST/ALT) values, whereas co-treatment with GW7647 and metformin greatly suppressed liver injury and fibrosis via activation of the AMP-activated protein kinase (AMPK) pathway. Further study revealed that co-treatment decreased the expression of inflammatory-, fibrogenesis-, and endoplasmic reticulum (ER) stress-related genes and increased the oxidized nicotinamide adenine dinucleotide (NAD)/reduced nicotinamide adenine dinucleotide (NADH) ratio, suggesting the superiority of co-treatment due to restoration of mitochondrial function. The additive benefits of a PPARα agonist and metformin in a HF-CDAA diet-induced advanced NASH model was firstly demonstrated, possibly through restoration of mitochondrial function and AMPK activation, which finally resulted in suppression of hepatic inflammation, ER stress, then, fibrosis.

The Appropriate Opportunity for Evaluating Liver Fibrosis by Using the FIB-4 Index in Patients with Nonalcoholic Fatty Liver Disease in Japan.

In patients with nonalcoholic fatty liver disease (NAFLD), liver fibrosis is the predictive factor for liver-related events and prognosis. This retrospective study aimed to evaluate longitudinal changes in the FIB-4 index and to determine a strategy for diagnosing and following patients with NAFLD using this index. We analyzed the FIB-4 index at baseline and after 1 and 5 years in 272 consecutive patients with biopsy-proven NAFLD. Of these, 52 patients underwent serial biopsies. The change in the FIB-4 index was correlated with changes in the fibrosis stage among these patients (p = 0.048). The median FIB-4 index was 1.64 at baseline, 1.45 at 1 year, and 1.74 at 5 years. The negative predictive value for advanced fibrosis at a low cutoff point was 90.4/90.1 at baseline/1 year. Its specificity at a high cutoff point increased from 65.0% at baseline to 82.3% at 1 year. Multivariate analysis identified the FIB-4 index at 1 year as a predictive factor for a FIB-4 index > 2.67 at 5 years. A FIB-4 index < 1.30 was acceptable for excluding advanced fibrosis at baseline. In contrast, to evaluate and predict advanced liver fibrosis with the FIB-4 index at a high cutoff point, we should use the index at 1 year after appropriate therapy.

Effect of pemafibrate on fatty acid levels and liver enzymes in non-alcoholic fatty liver disease patients with dyslipidemia: A single-arm, pilot study.

AIM: Dyslipidemia (DL) is commonly associated with non-alcoholic fatty liver disease (NAFLD). Pemafibrate, a selective peroxisome proliferator activated receptor α modulator (SPPARMα), has been shown to improve liver function among patients with DL. The aim of this single-arm prospective study is to evaluate the efficacy of pemafibrate in NAFLD patients with DL. METHODS: Twenty NAFLD patients with DL who received pemafibrate (0.1 mg) twice a day for 12 weeks were prospectively enrolled in this study. The primary end-point was change in serum alanine aminotransferase (ALT) levels from baseline to week 12. RESULTS: Serum ALT levels decreased from 75.1 IU/L at baseline to 43.6 IU/L at week 12 (P = 0.001). Significant improvements in triglyceride, high-density lipoprotein cholesterol, total fatty acid, saturated fatty acid (SFA), and unsaturated fatty acid were also noted. The serum level of remnant-like protein cholesterol, SFA, and polyunsaturated / saturated fatty acid ratio (PUFA / SFA ratio) at baseline were correlated with change in ALT level (r = -0.53, r = -0.57, and r = 0.46, respectively). Change in PUFA and change in PUFA / SFA ratio were negatively correlated with change in ALT level (r = -0.49 and r = -0.53). No hepatic or renal adverse events were reported. CONCLUSIONS: Selective peroxisome proliferator activated receptor α could be a promising novel agent for treatment of NAFLD patients with DL by regulating fatty acid composition. A further long-term large-scale trial is warranted to confirm the efficacy of SPPARMα on NAFLD with DL.

The Association between the Platelet Count and Liver Volume in Compensated Cirrhosis Patients after the Eradication of Hepatitis C virus by Direct-acting Antivirals.

Objective Although most patients who obtain a sustained virological response (SVR) show an improved liver function, some show decreased platelet counts after the eradication of hepatitis C virus (HCV). The aim of this retrospective study was to clarify the association of the liver and spleen volumes with the platelet count after SVR achieved by direct-acting antiviral (DAA) treatment. Methods This study enrolled 36 consecutive patients treated by DAAs who obtained an SVR between September 2014 and December 2018. The liver and spleen volumes were derived from computed tomography scans obtained at pretreatment, SVR, and 48 weeks after SVR. No patient developed hepatocellular carcinoma during this study. Results Compared with pretreatment, the median aspartate aminotransferase, alanine aminotransferase, albumin serum levels, and platelet counts were significantly improved at SVR and 48 weeks after SVR. The liver/spleen volumes per body weight had decreased significantly from 22.5/4.2 mL/kg at baseline to 21.1/3.6 mL/kg at 48 weeks after SVR. The change in the liver volume was associated with the change in the platelet count, and the change in the spleen volume was negatively associated with the change in the serum albumin level. A multivariate analysis identified the change in the liver volume (≥95%, odds ratio 76.9, p=0.005) as the factor associated with improvement in the platelet count at 48 weeks after SVR. The patients with an increased liver volume at 48 weeks after SVR showed an increased platelet count. Conclusion Both the liver and spleen volume decreased significantly after the eradication of HCV. The patients with a re-increased liver volume showed a rapid increase in the platelet count.

Attenuated effect of PNPLA3 on hepatic fibrosis by HSD17B13 in Japanese patients with non-alcoholic fatty liver disease.

BACKGROUND & AIMS: PNPLA3 rs738409 has been associated with increased risks of fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). Recently, carriage of the rs6834314 G allele, which is in high linkage with rs72613567 of 17-beta-hydroxysteroid dehydrogenase 13 (HSD17B13), was reported to be associated with a reduced risk of liver injury in NAFLD patients. We estimated the impact of these genetic variants on hepatic fibrosis in Japanese patients with NAFLD. METHODS: We analysed the associations of these genetic variants with liver histology in 290 Japanese patients with biopsy-proven NAFLD diagnosed during 2002-2019. During follow-up, 14 patients (4.8%) developed hepatocellular carcinoma. RESULTS: Prevalences of the PNPLA3 rs738409 genotypes were 0.17 for CC, 0.41 for CG, 0.42 for GG, and those for HSD17B13 rs6834314 were 0.54 for AA, 0.39 for AG and 0.07 for GG. There was no significant interaction between the PNPLA3 and HSD17B13 genotypes. Prevalences of advanced fibrosis according to PNPLA3/HSD17B13 genotypes were 0.16 for CC,CG/AG,GG, 0.20 for CC,CG/AA, 0.30 for GG/AG,GG and 0.37 for GG/AA. Multivariate analysis identified PNPLA3 GG as a predictor of advanced fibrosis (stage 3/4) in carriers of HSD17B13 AA (odds ratio 2.4, P = .041), but not HSD17B13 AG/GG (P = .776). The HSD17B13 genotype G was significantly associated with lower prevalences of severe inflammation and ballooning and tended to be associated with a higher prevalence of advanced steatosis. CONCLUSIONS: In Japanese patients with NAFLD, carriage of the HSD17B13 rs6834314 G allele attenuated the effect of the PNPLA3 rs738409 GG genotype on advanced hepatic fibrosis.

Effect of Sodium Glucose Cotransporter 2 Inhibitors on Renal Function in Patients with Nonalcoholic Fatty Liver Disease and Type 2 Diabetes in Japan.

Sodium-glucose cotransporter-2 inhibitors (SGLT2I) have been reported to have renal-protective effects in patients with type 2 diabetes (T2DM). This a retrospective study aimed to evaluate the effect of SGLT2I on renal function in patients with nonalcoholic fatty liver disease (NAFLD) and T2DM. We analyzed 69 consecutive patients with a biopsy-proven NAFLD and T2DM with an estimated glomerular filtration rate (eGFR) >60 mL/min. Of these 69 patients, 22 received SGLT2I and 47 were treated without SGLT2I. Liver function and eGFR were analyzed at baseline and after three years. Body mass index, liver function and HbA1c improved significantly in both groups. In the total population, the median eGFR declined from 80.7 mL/min at the baseline to 74.9 mL/min at the end of follow-up. The median eGFR at the baseline/end of follow-up was 81.2/80.4 mL/min in patients treated with SGLT2I and 80.2/70.8 mL/min in patients treated without SGLT2I. Multivariate analysis identified an increased FIB-4 index with an odds ratio (OR) of 4.721, (p = 0.045) and SGLT2I treatment (OR 0.263, p = 0.033) as predictive factors for decreased eGFR. SGLT2I treatment has a protective effect on the renal function for NAFLD with T2DM. A long-term, randomized, controlled trial is warranted to confirm the renal protective effect of SGLT2I in NAFLD patients with T2DM.

FIB-4 Index and Diabetes Mellitus Are Associated with Chronic Kidney Disease in Japanese Patients with Non-Alcoholic Fatty Liver Disease.

Non-alcoholic fatty liver disease (NAFLD) is associated with chronic kidney disease (CKD). The aim of this retrospective study was to determine the risk factors for progression of CKD in patients with biopsy-proven NAFLD including patatin-like phospholipase domain containing 3 (PNPLA3) polymorphism. A total of 344 patients with biopsy-proven NAFLD were enrolled consecutively in this study. Multivariate analysis identified males (odds ratio (OR) 5.46), age (per 1 year, OR 1.07), and FIB-4 index (≥1.30, OR 3.85) as factors associated with CKD. Of the 154 patients with a baseline estimated glomerular filtration rate (eGFR) ≥60 mL/min, 30 had a deterioration in CKD stage and 15 developed CKD after 3 years. Multivariate analysis identified diabetes mellitus (OR 2.44) as a risk factor for deterioration in CKD stage, while diabetes mellitus (OR 21.54) and baseline eGFR (per 1 mL/min OR 0.88) were risk factors for development of CKD. PNPLA3 did not affect the change in eGFR. In NAFLD patients, a high FIB-4 index was associated with CKD to increases in the index linked to reductions in eGFR. In order to prevent development of CKD, an appropriate therapy focusing on renal function is needed for NAFLD patients, especially those with diabetes.

Clinical and pathological features of sarcopenia-related indices in patients with non-alcoholic fatty liver disease.

BACKGROUND: Sarcopenia is diagnosed with the skeletal muscle index (SMI) or the sarcopenia index (SI). We previously reported that the ratio of skeletal muscle mass to body fat mass (SF ratio) was a novel index of sarcopenia in patients with non-alcoholic fatty liver disease (NAFLD). The aim of this retrospective study was to evaluate sarcopenia with these indices in patients with NAFLD. METHODS: One hundred and fifty-six consecutive patients with biopsy-proven NAFLD and alanine aminotransferase (ALT) >40 IU/L were enrolled. Liver function and body composition were evaluated in 121 patients after 12 months. We evaluated the relationship between histological findings, changes in liver function, and the SMI, SI, and SF ratio. RESULTS: Of the 156 patients enrolled, 13.5% and 26.3% were diagnosed with sarcopenia with the SMI and SI. In patients with hepatic fibrosis stage <2, the SI and the SF ratio were significantly greater than in patients with fibrosis stage ≥2. There was no difference in SMI between groups. In the cohort assessed at baseline and 12 months later, transaminase activity and SMI decreased significantly, and the SF ratio increased over time. A multivariate analysis revealed the presence of the PNPLA3 G allele and an increase in SF ratio (odds ratio, 7.406) as predictive factors of ALT reduction >30% from baseline. CONCLUSIONS: Due to the high prevalence of obesity, we should consider both skeletal muscle mass and body fat mass in the diagnosis and treatment of NAFLD. The SF ratio could be a useful index in sarcopenic NAFLD.

Increase in the skeletal muscle mass to body fat mass ratio predicts the decline in transaminase in patients with nonalcoholic fatty liver disease.

BACKGROUND: The aim of this retrospective study was to determine the effect of skeletal muscle and body fat on liver function in patients with nonalcoholic fatty liver disease (NAFLD) diagnosed by liver biopsy. METHODS: Among the 219 patients with NAFLD enrolled in this study was a cohort of 139 patients who had their body composition measured with Inbody720 at baseline and at ≥ 1 year postbaseline, to elucidate the relationship between liver function and changes in skeletal muscle and body fat mass. Multivariate analysis was used to identify factors influencing low skeletal muscle mass index (SMI, defined as 7 kg/m2 in men, and 5.7 kg/m2 in women) and the skeletal muscle mass to body fat mass ratio (SF ratio). RESULTS: Of the 219 patients enrolled, 27 (12.3%) had a low SMI. Patient age (> 70 years) and female gender were identified as risk factors for low SMI. Hepatic fibrosis was not associated with SMI. In the cohort followed up at baseline and 12 months later, transaminase activity, body fat mass, and SMI significantly decreased over time. Changes in the SF ratio were significantly associated with changes in liver function. An increase in the SF ratio [hazard ratio (HR) 10.99 in men, 6.849 in women] was a predictor of reduced ALT, independent of age and other backgrounds. CONCLUSIONS: In the patients with NAFLD, SMI was decreased, even in the early stages of NAFLD. Therapeutic strategies for NAFLD require a reduction in body fat mass and the maintenance of skeletal muscle is also needed.

Presence of varices in patients after hepatitis C virus eradication predicts deterioration in the FIB-4 index.

AIMS: The liver function of patients with hepatitis C virus (HCV) infection who obtained sustained virologic response (SVR) has been known to improve after HCV eradication. However, a predictor of liver function after SVR has not been definitively identified. The aim of this retrospective study was to identify a predictor of deteriorated liver function and Fibrosis-4 (FIB-4) index after SVR was achieved by direct-acting antiviral (DAA) treatment. METHODS: This study retrospectively enrolled 248 patients who obtained SVR by DAA treatment. None of the patients developed hepatocellular carcinoma during this study. Liver function was assessed at the end of treatment (EOT) and at 24, 48, 72, and 96 weeks after EOT. RESULTS: At 96 weeks after EOT, the serum aspartate aminotransferase and alanine aminotransferase levels were significantly decreased from those at EOT. The platelet count was significantly increased from 14.9 × 104 /µL at EOT to 17.1 × 104 /µL at 96 weeks after EOT. Ten patients showed an increased FIB-4 (>1.00) index. Multivariate analysis with 171 patients who underwent endoscopic assessment revealed that the presence of varices was an independent predictor of deterioration in the FIB-4 index (odds ratio, 5.56; P = 0.041). CONCLUSION: Most of the study patients who obtained SVR showed improved liver function after EOT. Patients without increasing platelet counts after SVR due to DAA therapy should be evaluated for complications induced by portal hypertension.