The role of FMO3 in metabolic diseases

Flavin containing monooxygenase 3(FMO3)is a member of the flavin monooxygenase family,which can oxidize the precursor Trimethylamine(TMA)provided from food to produce Trimethylamine N-oxide(TMAO).The autosomal recessive inherited disease caused by partial functional loss of Fmo3 gene,which leads to excessive excretion of TMA in body fluids and emits fishy odor,is called Fish Odor Syndrome or Trimethylaminuria.This disease has been documented for 3,000 years ago and was first reported in the case report in 1970.FMO3 mainly exists in the liver and can participate in the TMA-TMAO metabolic balance in intestinal microorganisms,liver,and kidneys,closely related to insulin resistance,diabetes,cholesterol metabolism,and cardiovascular disease.Due to its wide range of catalytic substrates and low susceptibility to metabolite accumulation,its role in drug metabolism,new drug development,and discovery of new drug targets are increasingly valued.This review will summarize the research progress on the metabolic process and localization of FMO3,congenital genetic defects,metabolic diseases,and its related possible mechanisms.

FibroScan-aspartate transaminase:A superior non-invasive model for diagnosing high-risk metabolic dysfunction-associated steatohepatitis

BACKGROUND Non-alcoholic fatty liver disease(NAFLD)with hepatic histological NAFLD activity score≥4 and fibrosis stage F≥2 is regarded as“at risk”non-alcoholic steatohepatitis(NASH).Based on an international consensus,NAFLD and NASH were renamed as metabolic dysfunction-associated steatotic liver disease(MASLD)and metabolic dysfunction-associated steatohepatitis(MASH),respectively;hence,we introduced the term“high-risk MASH”.Diagnostic values of seven non-invasive models,including FibroScan-aspartate transaminase(FAST),fibrosis-4(FIB-4),aspartate transaminase to platelet ratio index(APRI),etc.for high-risk MASH have rarely been studied and compared in MASLD.AIM To assess the clinical value of seven non-invasive models as alternatives to liver biopsy for diagnosing high-risk MASH.METHODS A retrospective analysis was conducted on 309 patients diagnosed with NAFLD via liver biopsy at Beijing Ditan Hospital,between January 2012 and December 2020.After screening for MASLD and the exclusion criteria,279 patients wereincluded and categorized into high-risk and non-high-risk MASH groups.Utilizing threshold values of each model,sensitivity,specificity,positive predictive value(PPV),and negative predictive values(NPV),were calculated.Receiver operating characteristic curves were constructed to evaluate their diagnostic efficacy based on the area under the curve(AUROC).RESULTS MASLD diagnostic criteria were met by 99.4%patients with NAFLD.The MASLD population was analyzed in two cohorts:Overall population(279 patients)and the subgroup(117 patients)who underwent liver transient elastography(FibroScan).In the overall population,FIB-4 showed better diagnostic efficacy and higher PPV,with sensitivity,specificity,PPV,NPV,and AUROC of 26.9%,95.2%,73.5%,72.2%,and 0.75.APRI,Forns index,and aspartate transaminase to alanine transaminase ratio(ARR)showed moderate diagnostic efficacy,whereas S index and gamma-glutamyl transpeptidase to platelet ratio(GPR)were relatively weaker.In the subgroup,FAST had the highest diagnostic efficacy,its sensitivity,specificity,PPV,NPV,and AUROC were 44.2%,92.3%,82.1%,67.4%,and 0.82.The FIB-4 AUROC was 0.76.S index and GPR exhibited almost no diagnostic value for high-risk MASH.CONCLUSION FAST and FIB-4 could replace liver biopsy as more effectively diagnostic methods for high-risk MASH compared to APRI,Forns index,ARR,S index,and GPR;FAST is superior to FIB-4.

Infrared thermography in metabolic diseases

The prevalence of metabolic diseases,some diseases that are seriously harmful for human health and affect the quality of life,is increasing year by year.Early detection and intervention is the common strategy to deal with them.Infrared thermography(IRT)is a special medical imaging technology which can capture the changes of skin temperature associated with metabolic disorders.It might be a new method for early detection of metabolic diseases.The purpose of this review is to summarize advances of the use of IRT in evaluating single metabolic disorder such as obesity,hyperglycemia and hypertension,complex metabolic disorders such as metabolic syndrome and target organ damage such as coronary artery atherosclerosis and diabetic foot.The characteristic of thermograms of metabolic disease patients,the changes of thermal maps during the development of the disease,and the lacks in current studies are also discussed in the article.

Scientific connotation of “treating different diseases with the same method” from the perspective of metabolic-immune dysregulation in inflammation-mediated carcinogenesis of digestive organs

Inflammation-mediated carcinogenesis develops in the context of chronic inflammation and is a significant cause of cancer within the digestive system.In the chronic inflammation microenvironment,the metabolic activity of tissue cells undergoes extensive changes,which interfere with the normal function of immune cells.Dysregulation of cell metabolism and immune function has been identified as a key factor contributing to inflammation-mediated carcinogenesis within the major digestive organs,such as the stomach,liver,and colorectum.This metabolic-immune imbalance also corresponds to traditional Chinese medicine(TCM)theories of“yin-yang disharmony”and“disharmony between Ying-nutrients and Wei-defense.”The metabolic-immune imbalance has also been regarded as the key factor supporting“treatment of different diseases with the same method”,in which the same approach is adopted in the treatment of different conditions.In the TCM treatment process,it is necessary to first identify TCM patterns and then apply the corresponding TCM to correct the dysregulated metabolic and immune function,thereby blocking the progression from inflammation to malignancy.Our study findings deepen the TCM understanding of metabolic-immune dysregulation and the relationship between metabolic-immune dysregulation,pattern identification,and treatment method.They also provide new insights for the treatment of inflammation-mediated carcinogenesis in major digestive organs and help us further explore the scientific connotation of the TCM strategy of“treating different diseases with the same method”.

Research Progress on Metabolic Diseases in Rural Areas

Through the review of relevant literature in recent years,it is found that the incidence rate of metabolic diseases in rural areas is on the rise:The related factors that may cause diseases include diet structure,exercise habits,medical resources and other aspects.At the same time,there are some limitations in the intervention and treatment measures of this kind of disease.It is urgent to carry out in-depth exploration for the special conditions in rural areas.By reviewing the research progress related to metabolic diseases in rural areas,more new ideas are provided for the treatment and improvement of metabolic diseases in rural areas.

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.

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.

Lipid droplets in the nervous system:involvement in cell metabolic homeostasis

Lipid droplets serve as primary storage organelles for neutral lipids in neurons,glial cells,and other cells in the nervous system.Lipid droplet formation begins with the synthesis of neutral lipids in the endoplasmic reticulum.Previously,lipid droplets were recognized for their role in maintaining lipid metabolism and energy homeostasis;however,recent research has shown that lipid droplets are highly adaptive organelles with diverse functions in the nervous system.In addition to their role in regulating cell metabolism,lipid droplets play a protective role in various cellular stress responses.Furthermore,lipid droplets exhibit specific functions in neurons and glial cells.Dysregulation of lipid droplet formation leads to cellular dysfunction,metabolic abnormalities,and nervous system diseases.This review aims to provide an overview of the role of lipid droplets in the nervous system,covering topics such as biogenesis,cellular specificity,and functions.Additionally,it will explore the association between lipid droplets and neurodegenerative disorders.Understanding the involvement of lipid droplets in cell metabolic homeostasis related to the nervous system is crucial to determine the underlying causes and in exploring potential therapeutic approaches for these diseases.

Disparate outcomes in Hispanic patients with metabolic dysfunctionassociated steatotic liver disease/steatohepatitis and type 2 diabetes: Large cohort study

BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD)and metabolic dysfunction-associated steatohepatitis(MASH)are a growing health burden across a significant portion of the global patient population.However,these conditions seem to have disparate rates and outcomes between different ethnic populations.The combination of MASLD/MASH and type 2 diabetes increases the risk of hepatocellular carcinoma(HCC),and Hispanic patients experience the greatest burden,particularly those in South Texas.AIM To compare outcomes between Hispanic and non-Hispanic patients in the United States,while further focusing on the Hispanic population within Southeast Texas to determine whether the documented disparity in outcomes is a function of geographical circumstance or if there is a more widespread reason that all clinicians must account for in prognostic consideration.METHODS This cohort analysis was conducted with data obtained from TriNetX,LLC(“TriNetX”),a global federated health research network that provides access to deidentified medical records from healthcare organizations worldwide.Two cohort networks were used:University of Texas Medical Branch(UTMB)hospital and the United States national database collective to determine whether disparities were related to geographic regions,like Southeast Texas.RESULTS This study findings revealed Hispanics/Latinos have a statistically significant higher occurrence of HCC,type 2 diabetes mellitus,and liver fibrosis/cirrhosis in both the United States and the UTMB Hispanic/Latino groups.Allcause mortality in Hispanics/Latinos was lower within the United States group and not statistically elevated in the UTMB cohort.CONCLUSION This would appear to support that Hispanic patients in Southeast Texas are not uniquely affected compared to the national Hispanic population.

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.

Application of medium-chain fatty acids in metabolic diseases

Medium-chain fatty acids(MCFAs),which are important dietary fats,can be rapidly metabolized to efficiently produce a high amount of energy owing to their unique transportation system.MCFAs have thus become high-value functional foods.MCFAs also have antibac-terial and immunoregulatory effects,help to maintain intestinal health,and have shown benefits for disease prevention and treatment.Therefore,they have the potential to be used for a variety of purposes.We herein describe the metabolic pathways involving MCFAs and their main biological functions in the human body.In addition,the effects of MCFAs as adjuvant therapy for different diseases,such as obesity,polycystic ovary syndrome,sarcopenia,and malignancy are summarized,and the likely mechanisms of action are discussed.Finally,we describe possible future clinical applications of MCFAs in the field of metabolic diseases.

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.

Perfluoropentane-based oxygen-loaded nanodroplets reduce microglial activation through metabolic reprogramming

Microglia,the primary immune cells within the brain,have gained recognition as a promising therapeutic target for managing neurodegenerative diseases within the central nervous system,including Parkinson’s disease.Nanoscale perfluorocarbon droplets have been reported to not only possess a high oxygen-carrying capacity,but also exhibit remarkable anti-inflammatory properties.However,the role of perfluoropentane in microglia-mediated central inflammatory reactions remains poorly understood.In this study,we developed perfluoropentane-based oxygen-loaded nanodroplets(PFP-OLNDs)and found that pretreatment with these droplets suppressed the lipopolysaccharide-induced activation of M1-type microglia in vitro and in vivo,and suppressed microglial activation in a mouse model of Parkinson’s disease.Microglial suppression led to a reduction in the inflammatory response,oxidative stress,and cell migration capacity in vitro.Consequently,the neurotoxic effects were mitigated,which alleviated neuronal degeneration.Additionally,ultrahigh-performance liquid chromatography–tandem mass spectrometry showed that the anti-inflammatory effects of PFP-OLNDs mainly resulted from the modulation of microglial metabolic reprogramming.We further showed that PFP-OLNDs regulated microglial metabolic reprogramming through the AKT-mTOR-HIF-1αpathway.Collectively,our findings suggest that the novel PFP-OLNDs constructed in this study alleviate microglia-mediated central inflammatory reactions through metabolic reprogramming.

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.

Screening for metabolic dysfunction-associated fatty liver disease:Time to discard the emperor’s clothes of normal liver enzymes?

Metabolic dysfunction-associated fatty liver disease(MAFLD)is the most prevalent chronic liver condition worldwide.Current liver enzyme-based screening methods have limitations that may missed diagnoses and treatment delays.Regarding Chen et al,the risk of developing MAFLD remains elevated even when alanine aminotransferase levels fall within the normal range.Therefore,there is an urgent need for advanced diagnostic techniques and updated algorithms to enhance the accuracy of MAFLD diagnosis and enable early intervention.This paper proposes two potential screening methods for identifying individuals who may be at risk of developing MAFLD:Lowering these thresholds and promoting the use of noninvasive liver fibrosis scores.

Effects of excess high-normal alanine aminotransferase levels in relation to new-onset metabolic dysfunction-associated fatty liver disease:Clinical implications

In this editorial,we comment on the article by Chen et al recently published in 2024.We focus the debate on whether reducing the upper limit of normal of alanine aminotransferase(ALT)would effectively identify cases of fibrosis in metabolic-dysfunction associated fatty liver disease(MAFLD).This is important given the increasing prevalence of MAFLD and obesity globally.Currently,a suitable screening test to identify patients in the general population does not exist and most patients are screened after the finding of an abnormal ALT.The authors of this paper challenge the idea of what a normal ALT is and whether that threshold should be lowered,particularly as their study found that 83.12%of their study population with a diagnosis of MAFLD had a normal ALT.The main advantages of screening would be to identify patients and provide intervention early,the mainstay of this being changing modifiable risk factors and monitoring for liver fibrosis.However,there is not enough suitable therapeutic options available as of yet although this is likely to change in the coming years with more targets for therapy being discovered.Semaglutide is one example of this which has demonstrated benefit with an acceptable side effect profile for those patients with MAFLD and obesity,although studies have not yet shown a significant improvement in fibrosis regression.It would also require a huge amount of resource if a reduced ALT level alone was used as criteria;it is more likely that current scoring systems such as fibrosis-4 may be amended to represent this additional risk.Currently,there is not a good argument to recommend wide-spread screening with a reduced ALT level as this is unlikely to be cost-effective.This is compounded by the fact that there is a significant heterogeneity in what is considered a normal ALT between laboratories.Although studies previously have suggested a more pragmatic approach in screening those over the age of 60,this is likely to change with the increasing incidence of obesity within the younger age groups.The main message from this study is that those who have hypercholesterolemia and high body metabolic index should have these risk factors modified to maintain a lower level of ALT to reduce the risk of progression to fibrosis and cirrhosis.

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.

Interplay between metabolic dysfunction-associated fatty liver disease and renal function: An intriguing pediatric perspective

Over recent years,the nomenclature of non-alcoholic fatty liver disease has undergone significant changes.Indeed,in 2020,an expert consensus panel proposed the term“Metabolic(dysfunction)associated fatty liver disease”(MAFLD)to underscore the close association of fatty liver with metabolic abnormalities,thereby highlighting the cardiometabolic risks(such as metabolic syndrome,type 2 diabetes,insulin resistance,and cardiovascular disease)faced by these patients since childhood.More recently,this term has been further replaced with metabolic associated steatotic liver disease.It is worth noting that emerging evidence not only supports a close and independent association of MAFLD with chronic kidney disease in adults but also indicates its interplay with metabolic impairments.However,comparable pediatric data remain limited.Given the progressive and chronic nature of both diseases and their prognostic cardiometabolic implications,this editorial aims to provide a pediatric perspective on the intriguing relationship between MAFLD and renal function in childhood.

Novel insights into autophagy in gastrointestinal pathologies,mechanisms in metabolic dysfunction-associated fatty liver disease and acute liver failure

In this editorial,we comment on three articles published in a recent issue of World Journal of Gastroenterology.There is a pressing need for new research on autophagy's role in gastrointestinal(GI)disorders,and also novel insights into some liver conditions,such as metabolic dysfunction-associated fatty liver disease(MAFLD)and acute liver failure(ALF).Despite advancements,understanding autophagy's intricate mechanisms and implications in these diseases remains incomplete.Moreover,MAFLD's pathogenesis,encompassing hepatic steatosis and metabolic dysregulation,require further elucidation.Similarly,the mechanisms underlying ALF,a severe hepatic dysfunction,are poorly understood.Innovative studies exploring the interplay between autophagy and GI disorders,as well as defined mechanisms of MAFLD and ALF,are crucial for identifying therapeutic targets and enhancing diagnostic and treatment strategies to mitigate the global burden of these diseases.

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.