LC-MS-based lipidomic analysis in distinguishing patients with nonalcoholic steatohepatitis from nonalcoholic fatty liver

Background: Nonalcoholic fatty liver disease(NAFLD) is one of the main liver diseases, and its pathologic profile includes nonalcoholic fatty liver(NAFL) and nonalcoholic steatohepatitis(NASH). However, there is no reliable non-invasive parameter in distinguishing NASH from NAFL in clinical practice. The present study was to find a non-invasive way to differentiate these two categories of NAFLD via lipidomic analysis. Methods: Lipidomic analysis was used to determine the changes of lipid moieties in blood from 20 NAFL and 10 NASH patients with liver biopsy. Liver histology was evaluated after hematoxylin and eosin staining and Masson’s trichrome staining. The profile of lipid metabolites in correlation with steatosis, inflammation, hepatocellular necroptosis, fibrosis, and NAFLD activity score(NAS) was analyzed. Results: Compared with NAFL patients, NASH patients had higher degree of steatosis, ballooning degeneration, lobular inflammation. A total of 434 different lipid molecules were identified, which were mainly composed of various phospholipids and triacylglycerols. Many lipids, such as phosphatidylcholine(PC)(P-22:0/18:1), sphingomyelin(SM)(d14:0/18:0), SM(d14:0/24:0), SM(d14:0/22:0), phosphatidylethanolamine(PE)(18:0/22:5), PC(O-22:2/12:0), and PC(26:1/11:0) were elevated in the NASH group compared to those in the NAFL group. Specific analysis revealed an overall lipidomic profile shift from NAFL to NASH, and identified valuable lipid moieties, such as PCs [PC(14:0/18:2), PE(18:0/22:5) and PC(26:1/11:0)] or plasmalogens [PC(O-22:0/0:0), PC(O-18:0/0:0), PC(O-16:0/0:0)], which were significantly altered in NASH patients. In addition, PC(14:0/18:2), phosphatidic acid(18:2/24:4) were positively correlated with NAS;whereas PC(18:0/0:0) was correlated positively with fibrosis score. Conclusions: The present study revealed overall lipidomic profile shift from NAFL to NASH, identified valuable lipid moieties which may be non-invasive biomarkers in the categorization of NAFLD. The correlations between lipid moieties and NAS and fibrosis scores indicate that these lipid biomarkers may be used to predict the severity of the disease.

PPARGC1A rs8192678 G>A polymorphism affects the severity of hepatic histological features and nonalcoholic steatohepatitis in patients with nonalcoholic fatty liver disease

BACKGROUND The association between PPARGC1A rs8192678 and nonalcoholic fatty liver disease(NAFLD)requires further confirmation.In addition,it is still unknown whether PPARGC1A rs8192678 is associated with hepatic histological features in NAFLD in the Chinese population.AIM To investigate the interaction between PPARGC1A rs8192678 and nonalcoholic steatohepatitis(NASH),and whether this polymorphism is associated with hepatic histological features.METHODS Fifty-nine patients with liver biopsy-proven NAFLD and 93 healthy controls were recruited to a cohort representing the Chinese Han population.The SAF(steatosis,activity,and fibrosis)scoring system was used for hepatic histopathological evaluation.The polymorphisms of PPARGC1A rs8192678 and patatin-like phospholipase domain-containing protein 3(PNPLA3)rs738409 were genotyped.The intrahepatic mRNA expression of PPARGC1A was evaluated by real-time polymerase chain reaction.RESULTS Thirty-seven patients with NAFLD had NASH,of which 12 were nonobese.The PPARGC1A rs8192678 risk A allele(carrying GA and AA genotypes)had the lowest P value in the dominant model;the odds ratio(OR)for NAFLD was 2.321[95%confidence interval(CI):1.121-4.806].After adjusting for age,sex,and the PNPLA3 rs738409 risk G allele,the PPARGC1A rs8192678 A allele was a risk factor for NAFLD(OR 2.202,95%CI:1.030-4.705,P=0.042).The genetic analysis showed that patients with NAFLD,moderate-to-severe steatosis(S2-3),and Activity 2-4(A≥2)were more likely to carry A in PPARGC1A rs8192678(OR 5.000,95%CI:1.343-18.620,P=0.012;and OR 4.071,95%CI:1.076-15.402,P=0.031).The multivariate logistic regression analysis showed that PPARGC1A rs8192678 risk A allele was also independently associated with S2-3,A≥2,and NASH(OR 6.190,95%CI:1.508-25.410,P=0.011;OR 4.506,95%CI 1.070-18.978,P=0.040;and OR 6.337,95%CI:1.135-35.392,P=0.035,respectively)after adjusting for age,sex,body mass index,and PNPLA3 rs738409 risk G allele.The results also showed that this polymorphism was associated with nonobese NASH(OR 22.000,95%CI:1.540-314.292,P=0.021).The intrahepatic expression of PPARGC1A mRNA was significantly lower in the group of patients who carried the risk A allele(P=0.014).CONCLUSION The PPARGC1A rs8192678 risk A allele is associated with NAFLD,and with S2-3,A≥2 and NASH in NAFLD patients,independent of PNPLA3 rs738409,and may be associated with nonobese NASH.

Promising diagnostic biomarkers of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis: From clinical proteomics to microbiome

Fatty liver has been present in the lives of patients and physicians for almost two centuries.Vast knowledge has been generated regarding its etiology and consequences,although a long path seeking novel and innovative diagnostic biomarkers for nonalcoholic fatty liver disease(NAFLD)and nonalcoholic steatohepatitis(NASH)is still envisioned.On the one hand,proteomics and lipidomics have emerged as potential noninvasive resources for NAFLD diagnosis.In contrast,metabolomics has been able to distinguish between NAFLD and NASH,even detecting degrees of fibrosis.On the other hand,genetic and epigenetic markers have been useful in monitoring disease progression,eventually functioning as target therapies.Other markers involved in immune dysregulation,oxidative stress,and inflammation are involved in the instauration and evolution of the disease.Finally,the fascinating gut microbiome is significantly involved in NAFLD and NASH.This review presents state-of-the-art biomarkers related to NAFLD and NASH and new promises that could eventually be positioned as diagnostic resources for this disease.As is evident,despite great advances in studying these biomarkers,there is still a long path before they translate into clinical benefits.

Case-control analysis of venous thromboembolism risk in nonalcoholic steatohepatitis diagnosed by transient elastography

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is the most common cause of chronic liver disease worldwide.Studies have shown a strong association between nonalcoholic steatohepatitis(NASH)cirrhosis and portal vein thrombosis.Specifically,there is paucity of data on the association of NASH and venous thromboembolism(VTE),with one such study predicting a 2.5-fold increased risk for VTE compared to other liver diseases in hospitalized patients.The mechanism is believed to be a hepatocellular injury,which causes a chronic inflammatory state leading to the unregulated activation of procoagulant factors.There has been no prior analysis of the degree of steatosis and fibrosis(measured using transient elastography,commonly known as FibroScan)in NASH and its association with VTE.AIM To examine the association between the degree of hepatic steatosis and fibrosis,quantified by transient elastography,and the incidence of VTE in patients with NASH.METHODS In our case-control study,we included patients with a documented diagnosis of NASH.We excluded patients with inherited thrombophilia,hemoglobinopathy,malignancy,alcohol use disorder,autoimmune hepatitis,and primary biliary cirrhosis.The collected data included age,demographics,tobacco use,recreational drug use,medical history,and vibration controlled transient elastography scores.VTE-specific data included the location,type of anticoagulant,need for hospital stay,and history of VTE recurrence.Steatosis was categorized as S0-S1(mild)and S2-S3(moderate to severe)based on the controlled attenuation parameter score.Fibrosis was classified based on the kilopascal score and graded as F0-F1(Metavir stage),F2,F3,and F4(cirrhosis).χ^(2) and Mann-Whitney U tests were used for the qualitative and quantitative variable analyses,respectively.Furthermore,we performed a logistic regression using VTE as the dependent variable.RESULTS A total of 415 patients were analyzed,and 386 met the inclusion criteria.51 and 335 patients were included in the VTE and non-VTE groups,respectively.Patients with VTE had a mean age of 60.63 years compared to 55.22 years in the non-VTE group(P<0.014).Patients with VTE had a higher body mass index(31.14 kg/m²vs 29.30 kg/m²)and a higher prevalence of diabetes mellitus(29.4%vs 13.1%).The history of NASH was significantly higher in the VTE group(45.1%vs 30.4%,P<0.037).Furthermore,moderate-to-severe steatosis was significantly higher in the VTE group(66.7%vs 47.2%,P<0.009).Similarly,the F2-F4 fibrosis grade had a prevalence of 58.8%in the VTE group compared to 38.5%in the non-VTE group(P<0.006).On logistic regression,using VTE as a dependent variable,diabetes mellitus had an odds ratio(OR)=1.702(P<0.015),and F2-F4 fibrosis grade had an OR=1.5(P<0.033).CONCLUSION Our analysis shows that NASH is an independent risk factor for VTE,especially deep vein thrombosis.There was a statistically significant association between the incidence of VTE,moderate-to-severe steatosis,and fibrosis.All hospitalized patients should be considered for medical thromboprophylaxis,particularly those with NASH.

Liver fibrosis markers of nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease(NAFLD) is one of themajor causes of chronic liver injury. NAFLD includes a wide range of clinical conditions from simple steatosis to nonalcoholic steatohepatitis(NASH), advanced fibrosis, and liver cirrhosis. The histological findings of NASH indicate hepatic steatosis and inflammation with characteristic hepatocyte injury(e.g., ballooning degeneration), as is observed in the patients with alcoholic liver disease. NASH is considered to be a potentially health-threatening disease that can progress to cirrhosis. A liver biopsy remains the most reliable diagnostic method to appropriately diagnose NASH, evaluate the severity of liver fibrosis, and determine the prognosis and optimal treatment. However, this invasive technique is associated with several limitations in routine use, and a number of biomarkers have been developed in order to predict the degree of liver fibrosis. In the present article, we review the current status of noninvasive biomarkers available to estimate liver fibrosis in the patients with NASH. We also discuss our recent findings on the use of the glycated albuminto-glycated hemoglobin ratio, which is a new index that correlates to various chronic liver diseases, including NASH.

Arachidyl amido cholanoic acid improves liver glucose and lipid homeostasis in nonalcoholic steatohepatitis via AMPK and mTOR regulation

BACKGROUND Arachidyl amido cholanoic acid(Aramchol)is a potent downregulator of hepatic stearoyl-CoA desaturase 1(SCD1)protein expression that reduces liver triglycerides and fibrosis in animal models of steatohepatitis.In a phase IIb clinical trial in patients with nonalcoholic steatohepatitis(NASH),52 wk of treatment with Aramchol reduced blood levels of glycated hemoglobin A1c,an indicator of glycemic control.AIM To assess lipid and glucose metabolism in mouse hepatocytes and in a NASH mouse model[induced with a 0.1%methionine and choline deficient diet(0.1MCD)]after treatment with Aramchol.METHODS Isolated primary mouse hepatocytes were incubated with 20μmol/L Aramchol or vehicle for 48 h.Subsequently,analyses were performed including Western blot,proteomics by mass spectrometry,and fluxomic analysis with 13C-uniformly labeled glucose.For the in vivo part of the study,male C57BL/6J mice were randomly fed a control or 0.1MCD for 4 wk and received 1 or 5 mg/kg/d Aramchol or vehicle by intragastric gavage for the last 2 wk.Liver metabolomics were assessed using ultra-high-performance liquid chromatography-time of flight-MS for the determination of glucose metabolism-related metabolites.RESULTS Combination of proteomics and Western blot analyses showed increased AMPK activity while the activity of nutrient sensor mTORC1 was decreased by Aramchol in hepatocytes.This translated into changes in the content of their downstream targets including proteins involved in fatty acid(FA)synthesis and oxidation[PACCα/β(S79),SCD1,CPT1A/B,HADHA,and HADHB],oxidative phosphorylation(NDUFA9,NDUFB11,NDUFS1,NDUFV1,ETFDH,and UQCRC2),tricarboxylic acid(TCA)cycle(MDH2,SUCLA2,and SUCLG2),and ribosome(P-p70S6K[T389]and P-S6[S235/S236]).Flux experiments with 13Cuniformely labeled glucose showed that TCA cycle cataplerosis was reduced by Aramchol in hepatocytes,as indicated by the increase in the number of rounds that malate remained in the TCA cycle.Finally,liver metabolomic analysis showed that glucose homeostasis was improved by Aramchol in 0.1MCD fed mice in a dose-dependent manner,showing normalization of glucose,G6P,F6P,UDP-glucose,and Rbl5P/Xyl5P.CONCLUSION Aramchol exerts its effect on glucose and lipid metabolism in NASH through activation of AMPK and inhibition of mTORC1,which in turn activate FAβ-oxidation and oxidative phosphorylation.

Obese diet-induced mouse models of nonalcoholic steatohepatitis-tracking disease by liver biopsy

AIM:To characterize development of diet-induced nonalcoholic steatohepatitis(NASH)by performing live biopsy in wild-type and genetically obese mice.METHODS:Male wild-type C57BL/6J(C57)mice(DIO NASH)and male Lep ob/Lep ob(ob/ob)mice(ob/ob-NASH were maintained on a diet high in trans-fat(40%)fructose(22%)and cholesterol(2%)for 26 and 12 wk respectively.A normal chow diet served as control in C57 mice(lean chow)and ob/ob mice(ob/ob chow)After the diet-induction period,mice were liver biopsied and a blinded histological assessment of steatosis and fibrosis was conducted.Mice were then stratified into groups counterbalanced for steatosis score and fibrosi stage and continued on diet and to receive daily PO dosing of vehicle for 8 wk.Global gene expression in liver tissue was assessed by RNA sequencing and bioin formatics.Metabolic parameters,plasma liver enzyme and lipids(total cholesterol,triglycerides)as well a hepatic lipids and collagen content were measured b biochemical analysis.Non-alcoholic fatty liver disease activity score(NAS)(steatosis/inflammation/ballooningdegeneration)and fibrosis were scored.Steatosis and fibrosis were also quantified using percent fractional area.RESULTS:Diet-induction for 26 and 12 wk in DIONASH and ob/ob-NASH mice,respectively,elicited progressive metabolic perturbations characterized by increased adiposity,total cholesterol and elevated plasma liver enzymes.The diet also induced clear histological features of NASH including hepatosteatosis and fibrosis.Overall,the metabolic NASH phenotype was more pronounced in ob/ob-NASH vs DIO-NASH mice.During the eight week repeated vehicle dosing period,the metabolic phenotype was sustained in DIO-NASH and ob/ob-NASH mice in conjunction with hepatomegaly and increased hepatic lipids and collagen accumulation.Histopathological scoring demonstrated significantly increased NAS of DIO-NASH mice(0 vs4.7±0.4,P<0.001 compared to lean chow)and ob/ob-NASH mice(2.4±0.3 vs 6.3±0.2,P<0.001compared to ob/ob chow),respectively.Furthermore,fibrosis stage was significantly elevated for DIO-NASH mice(0 vs 1.2±0.2,P<0.05 compared to lean chow)and ob/ob NASH(0.1±0.1 vs 3.0±0.2,P<0.001compared to ob/ob chow).Notably,fibrosis stage was significantly(P<0.001)increased in ob/ob-NASH mice,when compared to DIO-NASH mice.CONCLUSION:These data introduce the obese dietinduced DIO-NASH and ob/ob-NASH mouse models with biopsy-confirmed individual disease staging as a preclinical platform for evaluation of novel NASH therapeutics.

Female spontaneously diabetic Torii fatty rats develop nonalcoholic steatohepatitis-like hepatic lesions

AIM:To investigate the histological features of the liver in spontaneously diabetic Torii(SDT) fatty rats compared with age-matched Sprague-Dawley(SD) rats.METHODS:Female SDT Leprfa(SDT fatty) rats and age-matched SD rats were fed ad libitum. Body weight and biochemical parameters,such as serum glucose,triglyceride(TG),total cholesterol(TC),alanine aminotransferase(ALT) and aspartate aminotransferase(AST) levels as well as fatty acid and TG accumulation in the liver were evaluated at 8 wk of age in the nonfasting state and at 8-wk intervals from 8 to 40 wk of age. Histopathological examinations of the liver were performed using hematoxylin and eosin and Sirius Red staining as well as double staining for ED-1 and toluidine blue. The expression of genes involved in TG synthesis,inflammation,and fibrosis was examined in the liver.RESULTS:SDT fatty rats showed significantly increased body weight compared with SD rats. Serum glucose,TG,and TC levels were significantly higher in SDT fatty rats compared with SD rats. The serum AST and ALT levels in SDT fatty rats were significantly elevated at 8 wk of age compared with the levels in SD rats. Hepatic TG content was marked in SDT fatty rats from 8 to 32 wk of age. Histopathologically,severe hepatosteatosis accompanied by inflammation was observed at 8 wk of age,and fibrosis started to occur at 32 wk of age. Furthermore,Sirius Red and ED-1 staining were increased in the liver at 32 wk of age. Hepatic gene expression related to TG synthesis,inflammation and fibrosis tended to increase in SDT fatty rats compared with SD rats,and the gene expression related to TG secretion was decreased in SDT fatty rats compared with SD rats. CONCLUSION:Female SDT fatty rats have the potential to become an important animal model of nonalcoholic steatohepatitis with type 2 diabetes and obesity.

Noninvasive predictors for liver fibrosis in patients with nonalcoholic steatohepatitis

AIM:To evaluate certain anthropometric,clinical and laboratory features indicating liver fibrosis in nonalcoholic steatohepatitis and to establish the noninvasive markers for liver fibrosis.METHODS:Eighty-one patients (40 male,41 female) who were diagnosed with fatty liver by ultrasonographic examination and fulfilled the inclusion criteria participated in the study.Anamnesis,anthropometric,clinical and laboratory features of all cases were recorded and then liver biopsy was performed after obtaining patient consent.Steatosis,necroinflammation and liver fibrosis were examined according to age ≥ 45,gender,body mass index,central obesity,aspartate amino-transferase (AST)/alanine aminotransferase (ALT)>1,γ-glutamyltransferase (GGT)/ALT>1,platelet count,insulin,c-peptide levels and the presence of hypertension,diabetes,hypertriglyceridemia and insulin resis-tance.RESULTS:Eighty-one patients with non-alcoholic steatohepatitis (NASH) enrolled in the study.69 of 81 patients were diagnosed with NASH,11 were diagnosed with simple fatty liver and 1 was diagnosed with cirrhosis.AST/ALT>1,GGT/ALT>11,high serum ferritin and fasting insulin levels,the presence of diabetes,hypertension,hypertriglyceridemia and insulin resistance seemed to enhance the severity of steatosis,necroinflammation and fibrosis but these results were not statistically significant.CONCLUSION:Liver steatosis and fibrosis can occur in individuals with normal weight.There was no significant concordance between severity of liver histology and the presence of predictors for liver fibrosis including metabolic risk factors.

Circulating microRNA expression and nonalcoholic fatty liver disease in adolescents with severe obesity

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases in children and adolescents.NAFLD ranges in severity from isolated hepatic steatosis to nonalcoholic steatohepatitis(NASH),wherein hepatocellular inflammation and/or fibrosis coexist with steatosis.Circulating microRNA(miRNA)levels have been suggested to be altered in NAFLD,but the extent to which miRNA are related to NAFLD features remains unknown.This analysis tested the hypothesis that plasma miRNAs are significantly associated with histological features of NAFLD in adolescents.AIM To investigate the relationship between plasma miRNA expression and NAFLD features among adolescents with NAFLD.METHODS This study included 81 adolescents diagnosed with NAFLD and 54 adolescents without NAFLD from the Teen-Longitudinal Assessment of Bariatric Surgery study.Intra-operative core liver biopsies were collected from participants and used to characterize histological features of NAFLD.Plasma samples were collected during surgery for miRNA profiling.A total of 843 plasma miRNAs were profiled using the HTG EdgeSeq platform.We examined associations of plasma miRNAs and NAFLD features using logistic regression after adjusting for age,sex,race,and other key covariates.Ingenuity Pathways Analysis was used to identify biological functions of miRNAs that were associated with multiple histological features of NAFLD.RESULTS We identified 16 upregulated plasma miRNAs,including miR-193a-5p and miR-193b-5p,and 22 downregulated plasma miRNAs,including miR-1282 and miR-6734-5p,in adolescents with NAFLD.Moreover,52,16,15,and 9 plasma miRNAs were associated with NASH,fibrosis,ballooning degeneration,and lobular inflammation,respectively.Collectively,16 miRNAs were associated with two or more histological features of NAFLD.Among those miRNAs,miR-411-5p was downregulated in NASH,ballooning,and fibrosis,while miR-122-5p,miR-1343-5p,miR-193a-5p,miR-193b-5p,and miR-7845-5p were consistently and positively associated with all histological features of NAFLD.Pathway analysis revealed that most common pathways of miRNAs associated with multiple NAFLD features have been associated with tumor progression,while we also identified linkages between miR-122-5p and hepatitis C virus and between miR-199b-5p and chronic hepatitis B.CONCLUSION Plasma miRNAs were associated with NAFLD features in adolescent with severe obesity.Larger studies with more heterogeneous NAFLD phenotypes are needed to evaluate miRNAs as potential biomarkers of NAFLD.

Impact of lifestyle interventions on pathogenesis of nonalcoholic fatty liver disease

This editorial builds on the article titled“Establishment and validation of an adherence prediction system for lifestyle interventions in non-alcoholic fatty liver disease”by Zeng et al.We carried out a critical examination of nonalcoholic fatty liver disease(NAFLD)pathogenesis and how lifestyle interventions could facilitate disease resolution,particularly highlighting that non-alcoholic steatohepatitis(NASH)is a severe form of NAFLD.Our discussion details that weight loss is a pivotal factor in disease outcomes:A 3%-5%reduction is enough for resolution in 50%of non-obese individuals,while a 7%-10%reduction achieves similar benefits in obese individuals,as demonstrated by magnetic resonance spectroscopy.Additionally,the editorial underscores that such lifestyle changes are instrumental not only in resolving NAFLD but also in reversing hepatic steatosis and inflammation.These insights,derived from the research,emphasize the critical role of personalized lifestyle modifications in halting the progression of NAFLD to NASH and even reversing fibrosis,thus offering a template for effective patient management.

Dynamic alterations in the gut microbiota and metabolome during the development of methionine-choline-deficient diet-induced nonalcoholic steatohepatitis

AIM To investigate changes in gut microbiota and metabolism during nonalcoholic steatohepatitis(NASH) development in mice fed a methionine-choline-deficient(MCD) diet. METHODS Twenty-four male C57 BL/6 J mice were equally divided into four groups and fed a methionine-choline-sufficient diet for 2 wk(Control 2 w group,n = 6) or 4 wk(Control 4 w group,n = 6) or the MCD diet for 2 wk(MCD 2 w group,n = 6) or 4 wk(MCD 4 w group,n = 6). Liver injury,fibrosis,and intestinal barrier function were evaluated after 2 and 4 wk of feeding. The fecal microbiome and metabolome were studied using 16 s r RNA deep sequencing and gas chromatography-mass spectrometry. RESULTS The mice fed the MCD diet presented with simple hepatic steatosis and slight intestinal barrier deterioration after 2 wk. After 4 wk of feeding with the MCD diet,however,the mice developed prominent NASH with liver fibrosis,and the intestinal barrier was more impaired. Compared with the control diet,the MCD diet induced gradual gut microbiota dysbiosis,as evidenced by a marked decrease in the abundance of Alistipes and the(Eubacterium) coprostanoligenes group(P < 0.001 and P < 0.05,respectively) and a significant increase in Ruminococcaceae UCG 014 abundance(P < 0.05) after 2 wk. At 4 wk,the MCD diet significantly reduced the promising probiotic Bifidobacterium levels and markedly promoted Bacteroides abundance(P < 0.05,and P < 0.01,respectively). The fecal metabolomic profile was also substantially altered by the MCD diet: At 2 wk,arachidic acid,hexadecane,palmitic acid,and tetracosane were selected as potential biomarkers that were significantly different in the corresponding control group,and at 4 wk,cholic acid,cholesterol,arachidic acid,tetracosane,and stearic acid were selected. CONCLUSION The MCD diet induced persistent alterations in the gut microbiota and metabolome.

Mitochondrial DNA from hepatocytes as a ligand for TLR9: Drivers of nonalcoholic steatohepatitis?

Nonalcoholic fatty liver disease(NAFLD) is the most common liver disease worldwide, affecting approximately one third of the Western world. It consists of a wide spectrum of liver disorders, ranging from fatty liver to nonalcoholic steatohepatitis(NASH), which consists of steatosis, ballooning injury and inflammation. Despite an alarming growth in the statistics surrounding NAFLD, there are as yet no effective therapies for its treatment. Innate immune signaling has been thought to play a significant role in initiating and augmenting hepatic inflammation, contributing to the transition from nonalcoholic fatty liver to NASH. An immune response is triggered by countless signals called damage-associated molecular patterns(DAMPs) elicited by lipid-laden and damaged hepatocytes, which are recognized by pattern recognition receptors(PRRs) on hepatic immune cells to initiate inflammatory signaling. In this editorial, in addition to summarizing innate immune signaling in NAFLD and discussing potential therapies that target innate immune pathways, we have described a recent study that demonstrated that mitochondrial DNA serves as a DAMP activating a hepatic PRR, TLR9, in mice and in the plasma of NASH patients. In addition to identifying a new ligand for TLR9 during NASH progression, the study shows that blocking TLR9 reverses NASH, paving the way for the development of future NASH therapy.

Mouse models for investigating the underlying mechanisms of nonalcoholic steatohepatitis-derived hepatocellular carcinoma

As the incidence of hepatocellular carcinoma(HCC) caused by infection with the hepatotropic viruses hepatitis B and hepatitis C decreases, greater attention has become focused on HCC caused by nonalcoholic steatohepatitis(NASH), an advanced form of nonalcoholic fatty liver disease which has shown increasing prevalence in correspondence with the overall increase in metabolic syndrome over the recent decades. Several clinical population studies have shown a positive relationship between NASH and HCC, while also providing initial insights into the underlying mechanisms of HCC development from NASH. Research into the pathological progression of NASH to HCC has advanced by use of several beneficial rodent models. In this review, we summarize the established mouse models for preclinical research of NASH-associated HCC and discuss the underlying hepatic mechanisms of NASH-related tumorigenesis identified to date that could lead to new targets for treatment and prevention.

Cytokeratin-18 fragments and biomarkers of the metabolic syndrome in nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease(NAFLD)remains a leading cause of chronic liver disease.In the context of NAFLD,the presence of nonalcoholic steatohepatitis (NASH)portends an adverse prognosis with greater risk of liver fibrosis and cirrhosis.Although liver biopsy is the keystone of patient management in NAFLD,it is also increasingly clear that such evaluation has its limitations.The availability of biochemical markers of NAFLD and NASH has tremendous potential to radically alter management strategies for these conditions,as well as to monitor disease activity.Our article provides an overview of biomarker discovery and selection in the setting of NAFLD and highlights future directions in the field.

Potential risk factors for nonalcoholic steatohepatitis related to pancreatic secretions following pancreaticoduodenectomy

AIM: To identify risk factors for nonalcoholic steatohepatitis following pancreaticoduodenectomy, with a focus on factors related to pancreatic secretions. METHODS: The medical records of 228 patients who had a pancreaticoduodenectomy over a 16-mo period were reviewed retrospectively. The 193 patients who did not have fatty liver disease preoperatively were included in the final analysis. Hepatic steatosis was diagnosed using the differences between splenic and hepatic attenuation and liver-to-spleen attenuation as measured by non-enhanced computed tomography. RESULTS: Fifteen patients (7.8%) who showed postoperative hepatic fatty changes were assigned to Group A, and the remaining patients were assigned to Group B. Patient demographics, preoperative laboratory findings (including levels of C-peptide, glucagon, insulin and glucose tolerance test results), operation types, and final pathological findings did not differ significantly between the two groups; however, the frequency of pancreatic fistula (P = 0.020) and the method of pancreatic duct stenting (P = 0.005) showed significant differences between the groups. A multivari- ate analysis identified pancreatic fistula (HR = 3.332, P = 0.037) and external pancreatic duct stenting (HR = 4.530, P = 0.017) as independent risk factors for the development of postoperative steatohepatitis. CONCLUSION: Pancreatic fistula and external pancreatic duct stenting were identified as independent risk factors for the development of steatohepatitis following pancreaticoduodenectomy.

Hepatic fat quantification magnetic resonance for monitoring treatment response in pediatric nonalcoholic steatohepatitis

AIM: To evaluate the possibility of treatment effect monitoring using hepatic fat quantification magnetic resonance(MR) in pediatric nonalcoholic steatohepatitis(NASH).METHODS: We retrospectively reviewed the medical records of patients who received educational recommendations and vitamin E for NASH and underwent hepatic fat quantification MR from 2011 to 2013.Hepatic fat fraction(%) was measured using dual- and triple-echo gradient-recalled-echo sequences at 3T.The compliant and non-compliant groups were compared clinically,biochemically,and radiologically.RESULTS: Twenty seven patients(M:F = 24:3; mean age: 12 ± 2.3 years) were included(compliant group = 22,non-compliant = 5).None of the baseline findings differed between the 2 groups,except for triglyceride level(compliant vs non-compliant,167.7 mg/d L vs 74.2 mg/d L,P = 0.001).In the compliant group,high-density lipoprotein increased and all other parameters decreased after 1-year follow-up.However,there were various changes in the non-compliant group.Dualecho fat fraction(-19.2% vs 4.6,P < 0.001),tripleecho fat fraction(-13.4% vs 3.5,P < 0.001),alanine aminotransferase(-110.7 IU/L vs-10.6 IU/L,P = 0.047),total cholesterol(-18.1 mg/d L vs 3.8 mg/d L,P = 0.016),and triglyceride levels(-61.3 mg/d L vs 11.2 mg/d L,P = 0.013) were significantly decreased only in the compliant group.The change in body mass index and dual-echo fat fraction showed a positive correlation(ρ = 0.418,P = 0.030).CONCLUSION: Hepatic fat quantification MR can be a non-invasive,quantitative and useful tool for monitoring treatment effects in pediatric NASH.

Treating nonalcoholic steatohepatitis with antidiabetic drugs： Will GLP-1 agonists end the struggle？

Nonalcoholic fatty liver disease(NAFLD) is highly associated with insulin resistance(IR), type 2 diabetes mellitus and metabolic syndrome, being characterized as the hepatic component of metabolic syndrome. Despite its high prevalence, no pharmacological treatment has been established, as of yet. A growing body of evidence, however, shows that reducing IR can result in improvement of the biochemical and histological features of nonalcoholic steatohepatitis(NASH)-the aggressive form of NAFLD that can lead to cirrhosis and hepatocellular carcinoma. Unfortunately, the several trials that have assessed the effect of various antidiabetic agents to date have failed to establish an effective and safe treatment regimen for patients with NAFLD. Glucagon-like peptide-1(commonly known as GLP-1) agonists are a novel class of antidiabetic drugs that improve insulin sensitivity and promote weight loss. They also appear to have a direct effect on the lipid metabolism of hepatocytes, reducing hepatic steatosis. Several trials have demonstrated that GLP-1 agonists can reduce aminotransferase levels and improve liver histology in patients with NAFLD, suggesting that these agents could serve as an alternative treatment option for these patients. This manuscript discusses the role and potential mechanisms of GLP-1 agonists in the treatment of NASH.

Oral administration of a non-absorbable plant cellexpressed recombinant anti-TNF fusion protein induces immunomodulatory effects and alleviates nonalcoholic steatohepatitis

AIM To evaluate the immunomodulatory effect of oral administration of PRX-106 in the high-fat diet model.METHODS For 22 wk, C57BL/6 HFD-fed mice received daily oral treatments with BY-2 cells expressing recombinant antitumor necrosis factor alpha fusion protein(PRX-106). Mice were followed for serum liver enzyme and triglyceride levels, liver histology and intrahepatic and systemic FACS.RESULTS The orally administered non-absorbable PRX-106 w a s b i o l o g i c a l l y a c t i v e. A l t e r e d d i s t r i b u t i o n o f CD4+CD25+Fox P3+ between the liver and spleen and an increase in the intrasplenic-to-intrahepatic CD4+CD25+Fox P3+ ratio and a decrease in the intrasplenic-to-intrahepatic CD8+CD25+Fox P3+ ratio were observed. An increase in intrahepatic NKT cells and a decrease in the intrasplenic-to-intrahepatic NKT ratio were noted. Assessment of the CD4-to-CD8 ratios showed sequestration of CD8+ lymphocytes in the liver. These effects were associated with a decrease in serum triglyceride levels, decrease in the aspartate aminotransferase levels, serum glucose levels, and HOMA-IR score. A decrease in hepatic triglycerides content was observed in the high dose-treated mice.CONCLUSION Orally administered PRX-106 shows biological activity and exerts an immunomodulatory effect, alleviating liver damage. The data suggest that PRX-106 may provide an oral immunotherapy for nonalcoholic steatohepatitis.

A simple method for inducing nonalcoholic steatohepatitis with fibrosis

Background: Nonalcoholic fatty liver disease(NAFLD) is increasingly occurring in sedentary people, and may progress to NASH and hepatocellular carcinoma. It is essential to design affordable animal models for the study of various diseases, including fatty liver, which was the aim of the study. In this study, a high-fat diet was devised that triggers NASH’s animal model quickly and easily. High-fat diet(HFD) was used both with intra-mouth oral gavage and in combination with animal pellets.Methods: Twenty-four male C57 BL/6 J mice were divided into HFD and ND groups, which received a high-fat diet and a normal diet, respectively. At the end of the experiment(fourth week of treatment), body and liver weights, biochemical parameters, PPAR-α gene expression and histopathologic characteristics of the liver were evaluated.Results: During 4 weeks, body weight of mice did not show a significant increase in the HFD group compared to the ND group, while weight gain of the liver was significant. Histological assessment of the HFD group’s liver confirmed NASH symptoms. In the HFD group, HDL-c, SOD, catalase, FRAP, adiponectin, and PPAR-α decreased significantly, and lipid profiles, hepatic enzymes, MDA, leptin, and TNF-α showed a significant increase compared to the ND group.Conclusion: Our high-fat diet has successfully induced all aspects of NASH with fibrosis in 4 weeks, and with low cost.