Effects of methionine enkephalin on immune enhancement by reducing myeloid derived suppressor cells and reprogramming liver metabolism in colon cancer mice

OBJECTIVE To investigate enhanced immune function of methionine encephalin(MENK)and its anti-tumor mechanism in CT26 colon cancer mouse model.METHODS 3×10~6CT26 cells were implanted subcutaneously in BALB/c mice.Four days after,MENK was peritoneally administrated at the concentration of 20 mg·kg^(-1) for 14 d.The percentage of MDSCs in bone marrow,spleen,blood,tumor and liver were detected by flow cytometry.Non-esterified fatty acid(NEFA),triglycerides(TG)and total cholesterol(T-CHO)in liver homogenate were tested by a NEFA test kit,a TG test kit and a T-CHO test kit respectively.qRT-PCR and Western blot were used to measure m RNA and protein levels of inflammation-,glycometabolsim-and lipometabolsim-associated indexes in liver.RESULTS MENK decreased percentages of MDSCs in bone marrow,spleen,blood and tumor in colon cancer mice.MENK-treated mice displayed elevated ratio of CD4^+T and CD8^+T cells in spleen as well as increased T and B lymphocytes proliferation.Meanwhile,MENK also ameliorated liver damage reflected by lower levels of GPT and GOT in serum and reduced risks of cancer-associated index including inflammation,high lipid and high glucose.Furthermore,MENK lowered down the levels of NEFA,TG and T-CHO in liver homogenate.MENK treatment decreased expression of p-STAT3,increased expression of p-AKT,IRS1 and Glut4 at protein level as well as reduced lipogenesis-associated genes and elevated glycolysis-associated genes in liver of tumor bearing mice.Also,abated expression of genes associated with MDSCs generation(M-CSF,GM-CSF,IL-6,IL^(-1)β)and migration(S100A9,KC)was observed within shrunken subcutaneous tumor by MENK intervention.CONCLUSION MENK has the ability to strength immune function against colon cancer by reducing MDSCs and improving liver metabolism.

Effects of different energy levels in low-protein diet on liver lipid metabolism in the late-phase laying hens through the gut-liver axis

Background The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens.Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may improve fat deposition,but this also decreases the laying performance of hens.This study investigated the mechanism by which different energy levels in the low-protein diet influences liver lipid metabolism in late-phase laying hens through the enterohepatic axis to guide feed optimization and nutrition strategies.A total of 288 laying hens were randomly allocated to the normal-energy and normal-protein diet group(positive control:CK)or 1 of 3 groups:lowenergy and low-protein diet(LL),normal-energy and low-protein diet(NL),and high-energy and low-protein diet(HL)groups.The energy-to-protein ratios of the CK,LL,NL,and HL diets were 0.67,0.74,0.77,and 0.80,respectively.Results Compared with the CK group,egg quality deteriorated with increasing energy intake in late-phase laying hens fed low-protein diet.Hens fed LL,NL,and HL diets had significantly higher triglyceride,total cholesterol,acetylCo A carboxylase,and fatty acid synthase levels,but significantly lower hepatic lipase levels compared with the CK group.Liver transcriptome sequencing revealed that genes involved in fatty acid beta-oxidation(ACOX1,HADHA,EHHADH,and ACAA1)were downregulated,whereas genes related to fatty acid synthesis(SCD,FASN,and ACACA)were upregulated in LL group compared with the CK group.Comparison of the cecal microbiome showed that in hens fed an LL diet,Lactobacillus and Desulfovibrio were enriched,whereas riboflavin metabolism was suppressed.Cecal metabolites that were most significantly affected by the LL diet included several vitamins,such as riboflavin(vitamin B2),pantethine(vitamin B5 derivative),pyridoxine(vitamin B6),and 4-pyridoxic acid.Conclusion A lipid metabolism disorder due to deficiencies of vitamin B2 and pantethine originating from the metabolism of the cecal microbiome may be the underlying reason for fat accumulation in the liver of late-phase laying hens fed an LL diet.Based on the present study,we propose that targeting vitamin B2 and pantethine(vitamin B5 derivative)might be an effective strategy for improving lipid metabolism in late-phase laying hens fed a low-protein diet.

Liver disease in patients with transfusion-dependentβ-thalassemia:The emerging role of metabolism dysfunction-associated steatotic liver disease

In this Editorial,we highlight the possible role that metabolism dysfunction-associated steatotic liver disease(MASLD)may play in the future,regarding liver disease in patients with transfusion-dependent β-thalassemia(TDBT).MASLD is characterized by excessive accumulation of fat in the liver(hepatic steatosis),in the presence of cardiometabolic factors.There is a strong correlation between the occurrence of MASLD and insulin resistance,while its increased prevalence parallels the global epidemic of diabetes mellitus(DM)and obesity.Patients with TDBT need regular transfusions for life to ensure their survival.Through these transfusions,a large amount of iron is accumulated,which causes saturation of transferrin and leads to the circulation of free iron molecules,which cause damage to vital organs(primarily the liver and myocardium).Over the past,the main mechanisms for the development of liver disease in these patients have been the toxic effect of iron on the liver and chronic hepatitis C,for which modern and effective treatments have been found,resulting in successful treatment.Additional advances in the treatment and monitoring of these patients have led to a reduction in deaths,and an increase in their life expectancy.This increased survival makes them vulnerable to the onset of diseases,which until recently were mainly related to the non-thalassemic general population,such as obesity and DM.There is insufficient data in the literature regarding the prevalence of MASLD in this population or on the risk factors for its occurrence.However,it was recently shown by a study of 45 heavily transfused patients with beta-thalassemia(Padeniya et al,BJH),that the presence of steatosis is a factor influencing the value of liver elastography and thus liver fibrosis.These findings suggest that future research in the field of liver disease in patients with TDBT should be focused on the occurrence,the risk factors,and the effect of MASLD on these patients.

Ethanol extract of cassia seed alleviates metabolic dysfunction-associated steatotic liver disease by acting on multiple lipid metabolism-related pathways

Background and objective:In northern China's cold regions,the prevalence of metabolic dysfunction-associated steatotic liver disease(MASLD)exceeds 50%,significantly higher than the national and global rates.MASLD is an important risk factor for cardiovascular and cerebrovascular diseases,including coronary heart disease,stroke,and tumors,with no specific therapeutic drugs currently available.The ethanol extract of cassia seed(CSEE)has shown promise in lowering blood lipids and improving hepatic steatosis,but its mechanism in treating MASLD remains underexplored.This study aims to investigate the therapeutic effects and mechanisms of CSEE.Methods:MASLD models were established in male Wistar rats and golden hamsters using a high fat diet(HFD).CSEE(10,50,250 mg/kg)was administered via gavage for six weeks.Serum levels of total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),aspartate aminotransferase(AST),and alanine aminotransferase(ALT),as well as liver TC and TG,were measured using biochemical kits.Histopathological changes in the liver were evaluated using Oil Red O staining,Hematoxylin-eosin(H&E)staining,and transmission electron microscopy(TEM).HepG2 cell viability was assessed using the cell counting kit-8(CCK8)and Calcein-AM/PI staining.Network pharmacology was used to analyze drug-disease targets,and western blotting was used to confirm these predictions.Results:CSEE treatment significantly reduced serum levels of TC,TG,LDL-C,ALT,and AST,and improved liver weight,liver index,and hepatic lipid deposition in rats and golden hamsters.In addition,CSEE alleviated free fatty acid(FFA)-induced lipid deposition in HepG2 cells.Molecular biology experiments demonstrated that CSEE increased the protein levels of p-AMPK,p-ACC,PPARα,CPT1A,PI3K P110 and p-AKT,while decreasing the protein levels of SREBP1,FASN,C/EBPα,and PPARγ,thus improving hepatic lipid metabolism and reducing lipid deposition.The beneficial effects of CSEE were reversed by small molecule inhibitors of the signaling pathways in vitro.Conclusion:CSEE improves liver lipid metabolism and reduces lipid droplet deposition in Wistar rats and golden hamsters with MASLD by activating hepatic AMPK,PPARα,and PI3K/AKT signaling pathways.

Cumulative effects of excess high-normal alanine aminotransferase levels in relation to new-onset metabolic dysfunction-associated fatty liver disease in China

BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively.METHODS A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected.The incidence rate,cumulative times,and equally and unequally weighted cumulative effects of excess high-normal ALT levels(ehALT)were measured.Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD.RESULTS A total of 83.13%of participants with MAFLD had normal ALT levels.The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group.Compared with those in the low-normal ALT group,the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651[95%confidence interval(CI):1.199-2.273]and 1.535(95%CI:1.119-2.106)in the third quartile and 1.616(95%CI:1.162-2.246)and 1.580(95%CI:1.155-2.162)in the fourth quartile,respectively.CONCLUSION Most participants with MAFLD had normal ALT levels.Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD.

Omics-based biomarkers as useful tools in metabolic dysfunctionassociated steatotic liver disease clinical practice:How far are we?

Unmet needs exist in metabolic dysfunction-associated steatotic liver disease(MASLD)risk stratification.Our ability to identify patients with MASLD with advanced fibrosis and at higher risk for adverse outcomes is still limited.Incorporating novel biomarkers could represent a meaningful improvement to current risk predictors.With this aim,omics technologies have revolutionized the process of MASLD biomarker discovery over the past decades.While the research in this field is thriving,much of the publication has been haphazard,often using single-omics data and specimen sets of convenience,with many identified candidate biomarkers but lacking clinical validation and utility.If we incorporate these biomarkers to direct patients’management,it should be considered that the roadmap for translating a newly discovered omics-based signature to an actual,analytically valid test useful in MASLD clinical practice is rigorous and,therefore,not easily accomplished.This article presents an overview of this area’s current state,the conceivable opportunities and challenges of omics-based laboratory diagnostics,and a roadmap for improving MASLD biomarker research.

Metabolic dysfunction-associated steatotic liver disease:Navigating terminological evolution,diagnostic frontiers and therapeutic horizon-an editorial exploration

Metabolic dysfunction-associated steatotic liver disease(MASLD),once known as non-alcoholic fatty liver disease(NAFLD),represents a spectrum of liver disorders characterized by lipid accumulation within hepatocytes.The redefinition of NAFLD in 2023 marked a significant reposition in terminology,emphasizing a broader understanding of liver steatosis and its associated risks.MASLD is now recognized as a major risk factor for liver cirrhosis,hepatocellular carcinoma,and systemic complications such as cardiovascular diseases or systemic inflammation.Diagnostic challenges arise,particularly in identifying MASLD in lean individuals,necessitating updated diagnostic protocols and investing in non-invasive diagnostic tools.Therapeutically,there is an urgent need for effective treatments targeting MASLD,with emerging pharmacological options focusing on,among others,carbohydrate and lipid metabolism.Additionally,understanding the roles of bile acid metabolism,the microbiome,and dietary interventions in MASLD pathogenesis and management holds promise for innovative therapeutic approaches.There is a strong need to emphasize the importance of collaborative efforts in understanding,diagnosing,and managing MASLD to improve physicians’approaches and patient outcomes.

Update in lean metabolic dysfunction-associated steatotic liver disease

BACKGROUND A new nomenclature consensus has emerged for liver diseases that were previously known as non-alcoholic fatty liver disease(NAFLD)and metabolic dysfunction-associated fatty liver disease(MAFLD).They are now defined as metabolic dysfunction-associated steatotic liver disease(MASLD),which includes cardiometabolic criteria in adults.This condition,extensively studied in obese or overweight patients,constitutes around 30%of the population,with a steady increase worldwide.Lean patients account for approximately 10%-15%of the MASLD population.However,the pathogenesis is complex and is not well understood.AIM To systematically review the literature on the diagnosis,pathogenesis,characteristics,and prognosis in lean MASLD patients and provide an interpretation of these new criteria.METHODS We conducted a comprehensive database search on PubMed and Google Scholar between January 2012 and September 2023,specifically focusing on lean NAFLD,MAFLD,or MASLD patients.We include original articles with patients aged 18 years or older,with a lean body mass index categorized according to the World Health Organization criteria,using a cutoff of 25 kg/m2 for the general population and 23 kg/m2 for the Asian population.RESULTS We include 85 studies in our analysis.Our findings revealed that,for lean NAFLD patients,the prevalence rate varied widely,ranging from 3.8%to 34.1%.The precise pathogenesis mechanism remained elusive,with associations found in genetic variants,epigenetic modifications,and adaptative metabolic response.Common risk factors included metabolic syndrome,hypertension,and type 2 diabetes mellitus,but their prevalence varied based on the comparison group involving lean patients.Regarding non-invasive tools,Fibrosis-4 index outperformed the NAFLD fibrosis score in lean patients.Lifestyle modifications aided in reducing hepatic steatosis and improving cardiometabolic profiles,with some medications showing efficacy to a lesser extent.However,lean NAFLD patients exhibited a worse prognosis compared to the obese or overweight counterpart.CONCLUSION MASLD is a complex disease comprising epigenetic,genetic,and metabolic factors in its pathogenesis.Results vary across populations,gender,and age.Limited data exists on clinical practice guidelines for lean patients.Future studies employing this new nomenclature can contribute to standardizing and generalizing results among lean patients with steatotic liver disease.

Exploring non-invasive diagnostics for metabolic dysfunctionassociated fatty liver disease

The population with metabolic dysfunction-associated fatty liver disease(MAFLD)is increasingly common worldwide.Identification of people at risk of progression to advanced stages is necessary to timely offer interventions and appropriate care.Liver biopsy is currently considered the gold standard for the diagnosis and staging of MAFLD,but it has associated risks and limitations.This has spurred the exploration of non-invasive diagnostics for MAFLD,especially for steatohepatitis and fibrosis.These non-invasive approaches mostly include biomarkers and algorithms derived from anthropometric measurements,serum tests,imaging or stool metagenome profiling.However,they still need rigorous and widespread clinical validation for the diagnostic performance.

Hepatic angiotensin-converting enzyme 2 expression in metabolic dysfunction-associated steatotic liver disease and in patients with fatal COVID-19

BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD),characterised by hepatic lipid accumulation,causes inflammation and oxidative stress accompanied by cell damage and fibrosis.Liver injury(LI)is also frequently reported in patients hospitalised with coronavirus disease 2019(COVID-19),while preexisting MASLD increases the risk of LI and the development of COVID-19-associated cholangiopathy.Mechanisms of injury at the cellular level remain unclear,but it may be significant that severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)which causes COVID-19,uses angiotensin-converting expression enzyme 2(ACE2),a key regulator of the‘anti-inflammatory’arm of the renin-angiotensin system,for viral attachment and host cell invasion.AIM To determine if hepatic ACE2 levels are altered during progression of MASLD and in patients who died with severe COVID-19.METHODS ACE2 protein levels and localisation,and histological fibrosis and lipid droplet accumulation as markers of MASLD were determined in formalin-fixed liver tissue sections across the MASLD pathological spectrum(isolated hepatocellular steatosis,metabolic dysfunction-associated steatohepatitis(MASH)+/-fibrosis,end-stage cirrhosis)and in post-mortem tissues from patients who had died with severe COVID-19,using ACE2 immunohistochemistry and haematoxylin and eosin and picrosirius red staining of total collagen and lipid droplet areas,followed by quantification using machine learning-based image pixel classifiers.RESULTS ACE2 staining is primarily intracellular and concentrated in the cytoplasm of centrilobular hepatocytes and apical membranes of bile duct cholangiocytes.Strikingly,ACE2 protein levels are elevated in non-fibrotic MASH compared to healthy controls but not in the progression to MASH with fibrosis and in cirrhosis.ACE2 protein levels and histological fibrosis are not associated,but ACE2 and liver lipid droplet content are significantly correlated across the MASLD spectrum.Hepatic ACE2 levels are also increased in COVID-19 patients,especially those showing evidence of LI,but are not correlated with the presence of SARS-CoV-2 virus in the liver.However,there is a clear association between the hepatic lipid droplet content and the presence of the virus,suggesting a possible functional link.CONCLUSION Hepatic ACE2 levels were elevated in nonfibrotic MASH and COVID-19 patients with LI,while lipid accumulation may promote intra-hepatic SARS-CoV-2 replication,accelerating MASLD progression and COVID-19-mediated liver damage.

Impact of microplastics and nanoplastics on liver health:Current understanding and future research directions

With continuous population and economic growth in the 21st century,plastic pollution is a major global issue.However,the health concern of microplastics/nanoplastics(MPs/NPs)decomposed from plastic wastes has drawn public attention only in the recent decade.This article summarizes recent works dedicated to understanding the impact of MPs/NPs on the liver-the largest digestive organ,which is one of the primary routes that MPs/NPs enter human bodies.The interrelated mechanisms including oxidative stress,hepatocyte energy re-distribution,cell death and autophagy,as well as immune responses and inflammation,were also featured.In addition,the disturbance of microbiome and gut-liver axis,and the association with clinical diseases such as metabolic dysfunction-associated fatty liver disease,steatohepatitis,liver fibrosis,and cirrhosis were briefly discussed.Finally,we discussed potential directions in regard to this trending topic,highlighted current challenges in research,and proposed possible solutions.

Role of gut-liver axis and glucagon-like peptide-1 receptor agonists in the treatment of metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease(MAFLD)is a hepatic manifestation of the metabolic syndrome.It is one of the most common liver diseases worldwide and shows increasing prevalence rates in most countries.MAFLD is a progressive disease with the most severe cases presenting as advanced fibrosis or cirrhosis with an increased risk of hepatocellular carcinoma.Gut microbiota play a significant role in the pathogenesis and progression of MAFLD by disrupting the gut-liver axis.The mechanisms involved in maintaining gut-liver axis homeostasis are complex.One critical aspect involves preserving an appropriate intestinal barrier permeability and levels of intestinal lumen metabolites to ensure gutliver axis functionality.An increase in intestinal barrier permeability induces metabolic endotoxemia that leads to steatohepatitis.Moreover,alterations in the absorption of various metabolites can affect liver metabolism and induce liver steatosis and fibrosis.Glucagon-like peptide-1 receptor agonists(GLP-1 RAs)are a class of drugs developed for the treatment of type 2 diabetes mellitus.They are also commonly used to combat obesity and have been proven to be effective in reversing hepatic steatosis.The mechanisms reported to be involved in this effect include an improved regulation of glycemia,reduced lipid synthesis,β-oxidation of free fatty acids,and induction of autophagy in hepatic cells.Recently,multiple peptide receptor agonists have been introduced and are expected to increase the effectiveness of the treatment.A modulation of gut microbiota has also been observed with the use of these drugs that may contribute to the amelioration of MAFLD.This review presents the current understanding of the role of the gutliver axis in the development of MAFLD and use of members of the GLP-1 RA family as pleiotropic agents in the treatment of MAFLD.

Alanine aminotransferase predicts incident steatotic liver disease of metabolic etiology: Long life to the old biomarker!

Alanine aminotransferase(ALT)serum levels increase because of hepatocellular damage.Metabolic dysfunction-associated fatty liver disease(MAFLD),which identifies steatotic liver disease(SLD)associated with≥2 metabolic abnormalities,has prominent sexual differences.The Metabolic Syndrome defines a cluster comprising abdominal obesity,altered glucose metabolism,dyslipidemia,and hypertension.Male sex,body mass index,glucose,lipids,ferritin,hypertension,and age independently predict ALT levels among blood donors.Over the last few decades,the reference range of ALT levels has been animatedly debated owing to attempts to update sex-specific reference ranges.With this backset,Chen et al have recently published a study which has two main findings.First,>80%of indi-viduals with MAFLD had normal ALT levels.Second,there was a linear increa-sing trend in the association between cumulative excess high-normal ALT levels and the rate of incident MAFLD.This study has biologically credible findings.However,it inaccurately considered sex differences in the MAFLD arena.Therefore,future studies on SLD owing to metabolic dysfunction should adopt locally determined and prospectively validated reference ranges of ALT and carefully consider sex differences in liver enzymes and MAFLD pathobiology.

Metabolic dysfunction-associated steatotic liver disease heterogeneity: Need of subtyping

Metabolic dysfunction-associated steatotic liver disease(MASLD)is a widespread global disease with significant health burden.Unhealthy lifestyle,obesity,diabetes mellitus(DM),insulin resistance,and genetics have been implicated in the pathogenesis of MASLD.A significant degree of heterogeneity exists among each of above-mentioned risk factors.Heterogeneity of these risk factors translates into the heterogeneity of MASLD.On the other hand,MASLD can itself lead to insulin resistance and DM.Such heterogeneity makes it difficult to assess the natural course of an individual with MASLD in clinical practice.At present MASLD is considered as one disease despite the variability of etiopathogenic processes,and we lack the consensus definitions of unique subtypes of MASLD.In this review,pathogenic processes of MASLD are discussed and a need of subtyping is recommended.

Immune remodulation in pediatric inherited metabolic liver diseases

Inherited metabolic liver diseases arise from genetic mutations that lead to dis-ruptions in liver metabolic pathways and are predominantly observed in pedia-tric populations.The spectrum of genetic metabolic liver disorders is diverse,encompassing a range of conditions associated with aberrations in iron,copper,carbohydrate,lipid,protein,and amino acid metabolism.Historically,research in the domain of genetic metabolic liver diseases has predominantly concentrated on hepatic parenchymal cell alterations.Nevertheless,emerging studies suggest that inherited metabolic liver diseases exert significant influences on the immune microenvironment,both within the liver and systemically.This review endeavors to encapsulate the immunological features of genetic metabolic liver diseases,aiming to expand the horizons of researchers in this discipline,and to elucidate the underlying pathophysiological mechanisms pertinent to hereditary metabolic liver diseases and to propose innovative therapeutic approaches.

Impact of metabolic dysfunction-associated steatotic liver disease on the efficacy of immunotherapy in patients with chronic hepatitis B-related hepatocellular carcinoma

Objective:To investigate the impact of metabolic dysfunction-associated steatotic liver disease(MASLD)on the efficacy of immune checkpoint inhibitor(ICI)-based therapy in patients with chronic hepatitis B(CHB)-related hepatocellular carcinoma(HCC).Methods:A total of 155 patients with CHB-related HCC who received ICI–based therapy(in the Department of Hepatology,Tianjin Second People’s Hospital and Department of Hepatobiliary Oncology,Tianjin Medical University Cancer Institute&Hospital)between April 2021 and December 2023 were evaluated.Patients were divided into two groups:MASLD concurrent with CHB[MASLD-CHB](n=38),and CHB(n=117).Results:The median progression-free survival(PFS,6.9 months vs.9.3 months;P=0.001),progressive disease(57.89%vs.37.61%;P=0.028),and disease control rate(42.11%vs.62.39%;P=0.028)in the MASLD-CHB group were significantly worse than the CHB group.The median overall survival was not attained.The percentage of CD4+PD1+(17.56%vs.8.89%;P<0.001)and CD8+PD1+T cells(10.50%vs.7.42%;P=0.005)in patient samples from the MASLD-CHB group were significantly higher than the CHB group.Concurrent MASLD[hazard ratio(HR)=1.921;95%CI,1.138–3.245;P=0.015]and alpha-fetoprotein levels after 3 months of treatment(HR=2.412;95%CI,1.360–4.279;P=0.003)were independent risk factors for PFS in all patients.Conclusions:ICI-based therapy in patients with CHB-related HCC and concurrent MASLD resulted in poorer efficacy and shorter PFS compared to patients with CHB-related HCC alone.

Recent advances in age-related metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease(MASLD)affects approximately 25%of the world's population and has become a leading cause of chronic liver disease.In recent years,an increasing amount of data suggests that MASLD is associated with aging.As the population ages,age-related MASLD will become a major global health problem.Targeting an aging will become a new approach to the treatment of MASLD.This paper reviews the current studies on the role of aging-related factors and therapeutic targets in MASLD,including:Oxidative stress,autophagy,mitochondrial homeostasis,bile acid metabolism homeostasis,and dysbiosis.The aim is to identify effective therapeutic targets for age-related MASLD and its progression.

Alanine aminotransferase as a risk marker for new-onset metabolic dysfunction-associated fatty liver disease

In this editorial,we comment on the article by Chen et al.Metabolic dysfunction-associated fatty liver disease(MAFLD)is a global public health burden whose incidence has risen concurrently with overweight and obesity.Given its detri-mental health impact,early identification of at-risk individuals is crucial.MAFLD diagnosis is based on evidence of hepatic steatosis indicated by liver biopsy,imaging,or blood biomarkers,and one of the following conditions:Overweight/obesity,type 2 diabetes mellitus,or metabolic dysregulation.However,in large-scale epidemiological studies,liver biopsies are not feasible.The application of techniques such as ultrasonography,computed tomography,magnetic resonance imaging,and magnetic resonance spectroscopy is restricted by their limited sensitivity,low effectiveness,high costs,and need for specialized software.Blood biomarkers offer several advantages,particularly in large-scale epidemiological studies or clinical scenarios where traditional imaging techniques are impractical.Analysis of cumulative effects of excess high-normal blood alanine aminotrans-ferase(ALT)levels of blood ALT levels could facilitate identification of at-risk patients who might not be detected through conventional imaging methods.Accordingly,investigating the utility of blood biomarkers in MAFLD should enhance early detection and monitoring,enabling timely inter-vention and management and improving patient outcomes.

Metabolic dysfunction-associated steatotic liver disease:The question of long-term high-normal alanine aminotransferase as a screening test

The growing prevalence of metabolic dysfunction-associated steatotic liver disease(MASLD)is being driven by the obesity epidemic.The quest for solutions continues particularly with regard to early detection.This editorial comments on the utility of long-term high-normal alanine aminotransferase(ALT)in screening for MASLD.Chen et al found that new onset MASLD can be detected by repetitively high normal ALT.Implicit in this concept is the question of what should be the accepted upper limit of normal(ULN)for ALT.It was previously set at 40 IU/L based on studies that included people with subclinical liver disease but the new consensus is 30/19 U/L in healthy males/females.Thus,when Chen et al defines the ULN as 40 U/L,others may view it as excessively high.It is important to recognize the variables affecting ULN e.g.instrumentation,diurnal variations,exercise and ageing.These variables matter when the distinctions are subtle e.g.normal vs high-normal.In this regard,the utility of long-term high normal ALT as a disease marker could be enhanced by combining it with other biomarkers,imaging and MASLD genetics to create machine learning classifiers.All in all,Chen et al’s work on long-term high normal ALT as a marker of new-onset MASLD deserves merit.

Current remarks and future directions on the interactions between metabolic dysfunction-associated fatty liver disease and COVID-19

During the outbreak of the coronavirus disease 2019(COVID-19)pandemic,particular interest rose regarding the interaction between metabolic dysfunctionassociated fatty liver disease(MAFLD)and the COVID-19 infection.Several studies highlighted the fact that individuals with MAFLD had higher probability of severe acute respiratory syndrome coronavirus 2 infection and more severe adverse clinical outcomes.One of the proposed mechanisms is the inflammatory response pathway,especially the one involving cytokines,such as interleukin 6,which appeared particularly elevated in those patients and was deemed responsible for additional insult to the already damaged liver.This should increase our vigilance in terms of early detection,close follow up and early treatment for individuals with MAFLD and COVID-19 infection.In the direction of early diagnosis,biomarkers such as cytokeratin-18 and scoring systems such as Fibrosis-4 index score are proposed.COVID-19 is a newly described entity,expected to be of concern for the years to come,and MAFLD is a condition with an ever-increasing impact.Delineating the interaction between these two entities should be brought into the focus of research.Reducing morbidity and mortality of patients with COVID-19 and MAFLD should be the ultimate objective,and the optimal way to achieve this is by designing evidence-based prevention and treatment policies.