Liver as a new target organ in Alzheimer's disease:insight from cholesterol metabolism and its role in amyloid-beta clearance

Alzheimer's disease,the primary cause of dementia,is characterized by neuropathologies,such as amyloid plaques,synaptic and neuronal degeneration,and neurofibrillary tangles.Although amyloid plaques are the primary characteristic of Alzheimer's disease in the central nervous system and peripheral organs,targeting amyloid-beta clearance in the central nervous system has shown limited clinical efficacy in Alzheimer's disease treatment.Metabolic abnormalities are commonly observed in patients with Alzheimer's disease.The liver is the primary peripheral organ involved in amyloid-beta metabolism,playing a crucial role in the pathophysiology of Alzheimer's disease.Notably,impaired cholesterol metabolism in the liver may exacerbate the development of Alzheimer's disease.In this review,we explore the underlying causes of Alzheimer's disease and elucidate the role of the liver in amyloid-beta clearance and cholesterol metabolism.Furthermore,we propose that restoring normal cholesterol metabolism in the liver could represent a promising therapeutic strategy for addressing Alzheimer's disease.

Blood cell counts and nonalcoholic fatty liver disease: Evidence from Mendelian randomization analysis

BACKGROUND Previous research has highlighted correlations between blood cell counts and chronic liver disease.Nonetheless,the causal relationships remain unknown.AIM To evaluate the causal effect of blood cell traits on liver enzymes and nonalcoholic fatty liver disease(NAFLD)risk.METHODS Independent genetic variants strongly associated with blood cell traits were extracted from a genome-wide association study(GWAS)conducted by the Blood Cell Consortium.Summary-level data for liver enzymes were obtained from the United Kingdom Biobank.NAFLD data were obtained from a GWAS meta-analysis(8434 cases and 770180 controls,discovery dataset)and the Fingen GWAS(2275 cases and 372727 controls,replication dataset).This analysis was conducted using the inverse-variance weighted method,followed by various sensitivity analyses.RESULTS One SD increase in the genetically predicted haemoglobin concentration(HGB)was associated with aβof 0.0078(95%CI:0.0059-0.0096),0.0108(95%CI:0.0080-0.0136),0.0361(95%CI:0.0156-0.0567),and 0.0083(95%CI:00046-0.0121)for alkaline phosphatase(ALP),alanine aminotransferase(ALT),aspartate aminotransferase,and gammaglutamyl transferase,respectively.Genetically predicted haematocrit was associated with ALP(β=0.0078,95%CI:0.0052-0.0104)and ALT(β=0.0057,95%CI:0.0039-0.0075).Genetically determined HGB and the reticulocyte fraction of red blood cells increased the risk of NAFLD[odds ratio(OR)=1.199,95%CI:1.087-1.322]and(OR=1.157,95%CI:1.071-1.250).The results of the sensitivity analyses remained significant.CONCLUSION Novel causal blood cell traits related to liver enzymes and NAFLD development were revealed through Mendelian randomization analysis,which may facilitate the diagnosis and prevention of NAFLD.

Ferritinophagy: A new idea for liver diseases regulated by ferroptosis

Background:The discovery of regulatory cell death has led to a breakthrough in the therapeutic field.Various forms of cell death,such as necrosis,apoptosis,pyroptosis,autophagy,and ferroptosis,play an important role in the development of liver diseases.In general,more than one form of cell death pathways is responsible for the disease state.Therefore,it is particularly important to study the regulation and interaction of various cell death forms in liver diseases.Data sources:We performed a PubMed search up to November 2022 with the following keywords:ferritinophagy,ferroptosis,and liver disease.We also used terms such as signal path,inducer,and inhibitor to supplement the query results.Results:This review summarized the basic characteristics of ferritinophagy and ferroptosis and the regulation of ferroptosis by ferritinophagy and reviewed the key targets and treatment strategies of ferroptosis in different liver diseases.Conclusions:Ferritinophagy is a potential therapeutic target in ferroptosis-related liver diseases.

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.

Ferroptosis in liver diseases:Fundamental mechanism and clinical implications

This editorial discusses a recently published paper in the World Journal of Gastroenterology.Our research focuses on p53's regulatory mechanism for controlling ferroptosis,as well as the intricate connection between ferroptosis and liver diseases.Ferroptosis is a specific form of programmed cell death that is dependent on iron and displays unique features in terms of morphology,biology,and genetics,distinguishing it from other forms of cell death.Ferroptosis can affect the liver,which is a crucial organ responsible for iron storage and metabolism.Mounting evidence indicates a robust correlation between ferroptosis and the advancement of liver disorders.P53 has a dual effect on ferroptosis through various distinct signaling pathways.However,additional investigations are required to clarify the regulatory function of p53 metabolic targets in this complex association with ferroptosis.In the future,researchers should clarify the mechanisms by which ferroptosis and other forms of programmed cell death contribute to the progression of liver diseases.Identifying and controlling important regulatory factors associated with ferroptosis present a promising therapeutic strategy for liver disorders.

Characterization of acute-on-chronic liver diseases: A multicenter prospective cohort study

BACKGROUND Acute-on-chronic liver disease(AoCLD)accounts for the majority of patients hospitalized in the Department of Hepatology or Infectious Diseases.AIM To explore the characterization of AoCLD to provide theoretical guidance for the accurate diagnosis and prognosis of AoCLD.METHODS Patients with AoCLD from the Chinese Acute-on-Chronic Liver Failure(ACLF)study cohort were included in this study.The clinical characteristics and outcomes,and the 90-d survival rate associated with each clinical type of AoCLD were analyzed,using the Kaplan-Meier method and the log-rank test.RESULTS A total of 3375 patients with AoCLD were enrolled,including 1679(49.7%)patients with liver cirrhosis acute decompensation(LC-AD),850(25.2%)patients with ACLF,577(17.1%)patients with chronic hepatitis acute exacer-bation(CHAE),and 269(8.0%)patients with liver cirrhosis active phase(LC-A).The most common cause of chronic liver disease(CLD)was HBV infection(71.4%).The most common precipitants of AoCLD was bacterial infection(22.8%).The 90-d mortality rates of each clinical subtype of AoCLD were 43.4%(232/535)for type-C ACLF,36.0%(36/100)for type-B ACLF,27.0%(58/215)for type-A ACLF,9.0%(151/1679)for LC-AD,3.0%(8/269)for LC-A,and 1.2%(7/577)for CHAE.CONCLUSION HBV infection is the main cause of CLD,and bacterial infection is the main precipitant of AoCLD.The most common clinical type of AoCLD is LC-AD.Early diagnosis and timely intervention are needed to reduce the mortality of patients with LC-AD or ACLF.

Interleukin-mediated therapies in liver diseases and comorbidity effects

Cytokines like interleukins(ILs)play important roles in inflammation and innate immune.Yang and Zhang carried out an interesting study related to ILs and hepatic diseases.They described the role of ILs in the pathogenesis and resolution of hepatic disorders.The authors summarized alcohol-related liver disease and virus-induced hepatitis,as far as clinical studies a fortiori carried out on ILmediated treatments pertaining to these dysfunctions.This editorial contributes to the review by Yang and Zhang titled,"Interleukins in liver disease treatment",and focuses on therapies mediated by ILs in comorbid liver diseases.The documentary search was conducted on recent pertinent literature,primarily using the Google Scholar and PubMed databases.

Dynamic changes and clinical value of lipocalin 2 in liver diseases caused by microbial infections

Lipocalin 2(LCN2)plays a pivotal role in iron metabolism,particularly in the context of microbial infection resistance(e.g.,viruses,bacteria,parasites,etc.).LCN2 combats microbial infection by directly assisting the body in competing with microorganisms for iron,inducing immune cells to secrete various cytokines to enhance systemic immune responses,or recruiting neutrophils to infectious sites.The liver serves as the primary organ for LCN2 secretion during microbial infections.This review encapsulates recent advances in dynamic changes,clinical values,and the effects of LCN2 in infectious liver diseases caused by various microbial microorganisms.

Linking fatty liver diseases to hepatocellular carcinoma by hepatic stellate cells

Hepatic stellate cells(HSCs),a distinct category of non-parenchymal cells in the liver,are critical for liver homeostasis.In healthy livers,HSCs remain non-proliferative and quiescent.However,under conditions of acute or chronic liver damage,HSCs are activated and participate in the progression and regulation of liver diseases such as liver fibrosis,cirrhosis,and liver cancer.Fatty liver diseases(FLD),including nonalcoholic(NAFLD)and alcoholrelated(ALD),are common chronic inflammatory conditions of the liver.These diseases,often resulting from multiple metabolic disorders,can progress through a sequence of inflammation,fibrosis,and ultimately,cancer.In this review,we focused on the activation and regulatory mechanism of HSCs in the context of FLD.We summarized the molecular pathways of activated HSCs(aHSCs)in mediating FLD and their role in promoting liver tumor development from the perspectives of cell proliferation,invasion,metastasis,angiogenesis,immunosuppression,and chemo-resistance.We aimed to offer an in-depth discussion on the reciprocal regulatory interactions between FLD and HSC activation,providing new insights for researchers in this field.

Peripheral blood lymphocytes DNA in patients with chronic liver diseases

BACKGROUND: Viral replication in blood cells with nucleases may lead to the damage of lymphocytes genetic apparatus and the beginning of immunopathological reactions. AIM: Of this investigation is to reveal the damage to peripheral blood lymphocytes (PBL) DNA in the patients with chronic liver diseases. MATERIALS AND METHODS: Sixteen-nine patients with chronic liver diseases (37 patients with chronic viral hepatitis, 2 patients with liver cirrhosis of mixed etiology (alcohol+virus G), 30 women with primary biliary cirrhosis-PBC) were examined. The condition of DNA structure of PBL was measured by the fluorescence analysis of DNA unwinding (FADU) technique with modification. Changes of fluorescence (in %) reflected the DNA distractions degree (the presence of DNA single-stranded breaks and alkalinelabile sights). RESULTS AND CONCLUSION: The quantity of DNA single-stranded breaks and alkalinelabile sights in DNA in all patients with chronic viral hepatitis didn't differ from the control group, excluding the patients with chronic hepatitis (CH) C+G. Patients with HGV and TTV monoinfection had demonstrated the increase of the DNA single-stranded breaks PBL quantity. This fact may be connected with hypothesis about the viruses replication in white blood cells discussed in the literature. Tendency to increase quantity of DNA PBL damages in the patients with primary biliary cirrhosis (PBC) accordingly to the alkaline phosphatase activity increase was revealed. Significant decrease of the DNA single-stranded breaks and alkalinelabile sights in the PBC patients that were treated with prednisone was demonstrated. Probably, the tendency to increase the quantity of DNA single stranded breaks and alkalinelabile sights in lymphocytes of the PBC patients was depended on the surplus of the blood bile acid content.

Machine learning approaches using blood biomarkers in nonalcoholic fatty liver diseases

The prevalence of nonalcoholic fatty liver disease(NAFLD)is an important public health concern.Early diagnosis of NAFLD and potential progression to nonalcoholic steatohepatitis(NASH),could reduce the further advance of the disease,and improve patient outcomes.Aiming to support patient diagnostic and predict specific outcomes,the interest in artificial intelligence(AI)methods in hepatology has dramatically increased,especially with the application of lessinvasive biomarkers.In this review,our objective was twofold:Firstly,we presented the most frequent blood biomarkers in NAFLD and NASH and secondly,we reviewed recent literature regarding the use of machine learning(ML)methods to predict NAFLD and NASH in large cohorts.Strikingly,these studies provide insights into ML application in NAFLD patients'prognostics and ranked blood biomarkers are able to provide a recognizable signature allowing cost-effective NAFLD prediction and also differentiating NASH patients.Future studies should consider the limitations in the current literature and expand the application of these algorithms in different populations,fortifying an already promising tool in medical science.

Assessment of natural and interleukin-2-induced production of interferon-gamma in patients with liver diseases

AIMS To clarify whether the lower interferon gamma (IFNγ) production by lymphocytes in patients with liver diseases is due to defects of lymphocytes themselves or of other cofactors such as interleukin-2(IL-2). METHODS Peripheral blood mononuclear cells (PBMCs) from patients with various liver diseases were cultured with or without PHA and IL-2. The cells were harvested and counted and the su- pernatants were tested for IFNγ by a sensitive and quantitative ABC-ELISA. RESULTS IFNγ was not round in serum samples from patients as well as normal individuals. However,in supernatants of non-in- duced and induced PBMCs,IFN7 was detected by ABC-ELISA. In non-induced PBMCs (group 1),the content of IFNγ in super- natants from control,CAH,CPH and HCC was 8.72 μg/L, 5.03 μg/L,6.02 μg/L and 4.91 μg/L respectively. The pro- duction of IFNγ in liver disease was significantly decreased,com- pared to control. In group 2 in which PBMCs were stimulated with PHA,the content of IFNγ was 22.71,17.12,14.54 and 17.63 μg/L respectively. In group 3 in which PBMCs were in- duced by IL-2,the amount of IFN7 in supernatant from control (60.67 μg/L) was much larger than those from CAH (21.70 μg/ L),CPH (24.00 μg/L) and HCC (19.15 μg/L) (P<0.01). Comparing the amount of IFNγ in group 3 (IL-2-induced) with that in group 1 (non-induced),we found that IFNγ production was en- hanced by nearly 4 folds in liver diseases and by over 7 folds in control,Whereas the number of PBMCs,whether from liver dis- eases or from control,was increased by only approximately 3 folds. CONCLUSIONS The decreased production of IFNγ in liver dis- eases including HCC is mainly due to endogenous defects of lym- phocytes though the defects of stimulating cofactors such as IL-2 may also be involved.

Muscle strength and non-alcoholic fatty liver disease/metabolicassociated fatty liver disease

This editorial comments on an article published in a recent issue of World Journal of Gastroenterology,entitled“Association of low muscle strength with metabolic dysfunction-associated fatty liver disease:A nationwide study”.We focused on the association between muscle strength and the incidence of non-alcoholic fatty liver disease(NAFLD)and metabolic-associated fatty liver disease(MAFLD),as well as the mechanisms underlying the correlation and related clinical applications.NAFLD,which is now redefined as MAFLD,is one of the most common chronic liver diseases globally with an increasing prevalence and is characterized by malnutrition,which may contribute to decreased muscle strength.Reduction of muscle strength reportedly has a pathogenesis similar to that of NAFLD/MAFLD,including insulin resistance,inflammation,sedentary behavior,as well as insufficient vitamin D.Multiple studies have focused on the relationship between sarcopenia or muscle strength and NAFLD.However,studies investigating the relationship between muscle strength and MAFLD are limited.Owing to the shortage of specific medications for NAFLD/MAFLD treatment,early detection is essential.Furthermore,the relationship between muscle strength and NAFLD/MAFLD suggests that improvements in muscle strength may have an impact on disease prevention and may provide novel insights into treatments including dietary therapy,as well as tailored physical activity.

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.

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.

Metabolic disease and the liver: A review

Metabolic dysfunction-associated steatotic liver disease(MASLD)is the most common liver disease worldwide,with an estimated prevalence of 31%in Latin America.The presence of metabolic comorbidities coexisting with liver disease varies substantially among populations.It is acknowledged that obesity is boosting the type 2 diabetes mellitus“epidemic,”and both conditions are significant contributors to the increasing number of patients with MASLD.Nonalcoholic steatohepatitis represents a condition of chronic liver inflammation and is considered the most severe form of MASLD.MASLD diagnosis is based on the presence of steatosis,noninvasive scores and altered liver tests.Noninvasive scores of liver fibrosis,such as serum biomarkers,which should be used in primary care to rule out advanced fibrosis,are simple,inexpensive,and widely available.Currently,guidelines from international hepatology societies recommend using noninvasive strategies to simplify case finding and management of high-risk patients with MASLD in clinical practice.Unfortunately,there is no definite pharmacological treatment for the condition.Creating public health policies to treat patients with risk factors for MASLD prevention is essential.

Blood-brain barrier pathology in cerebral small vessel disease

Cerebral small vessel disease is a neurological disease that affects the brain microvasculature and which is commonly observed among the elderly.Although at first it was considered innocuous,small vessel disease is nowadays regarded as one of the major vascular causes of dementia.Radiological signs of small vessel disease include small subcortical infarcts,white matter magnetic resonance imaging hyperintensities,lacunes,enlarged perivascular spaces,cerebral microbleeds,and brain atrophy;however,great heterogeneity in clinical symptoms is observed in small vessel disease patients.The pathophysiology of these lesions has been linked to multiple processes,such as hypoperfusion,defective cerebrovascular reactivity,and blood-brain barrier dysfunction.Notably,studies on small vessel disease suggest that blood-brain barrier dysfunction is among the earliest mechanisms in small vessel disease and might contribute to the development of the hallmarks of small vessel disease.Therefore,the purpose of this review is to provide a new foundation in the study of small vessel disease pathology.First,we discuss the main structural domains and functions of the blood-brain barrier.Secondly,we review the most recent evidence on blood-brain barrier dysfunction linked to small vessel disease.Finally,we conclude with a discussion on future perspectives and propose potential treatment targets and interventions.

Excess cardiovascular mortality in men with non-alcoholic fatty liver disease:A cause for concern!

Non-alcoholic fatty liver disease(NAFLD)has emerged as the commonest cause of chronic liver disease worldwide in recent years.With time,our understanding of NAFLD has evolved from an isolated liver condition to a systemic disease with significant manifestations beyond the liver.Amongst them,cardiovascular diseases(CVDs)are the most important and clinically relevant.Recent research supports a strong independent link between NALFD and CVD beyond the shared risk factors and pathophysiology.Female sex hormones are well known to not only protect against CVD in pre-menopausal females,but also contribute to improved adipose tissue function and preventing its systemic deposition.Recent research highlights the increased risk of major adverse cardiovascular-cerebral events(MACCE)amongst male with NAFLD compared to females.Further,racial variation was observed in MACCE outcomes in NAFLD,with excess mortality in the Native Americans and Asian Pacific Islanders compared to the other races.

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.

Current perspectives on mesenchymal stem cells as a potential therapeutic strategy for non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)has emerged as a significant health challenge,characterized by its widespread prevalence,intricate natural progression and multifaceted pathogenesis.Although NAFLD initially presents as benign fat accumulation,it may progress to steatosis,non-alcoholic steatohepatitis,cirrhosis,and hepatocellular carcinoma.Mesenchymal stem cells(MSCs)are recognized for their intrinsic self-renewal,superior biocompatibility,and minimal immunogenicity,positioning them as a therapeutic innovation for liver diseases.Therefore,this review aims to elucidate the potential roles of MSCs in alleviating the progression of NAFLD by alteration of underlying molecular pathways,including glycolipid metabolism,inflammation,oxidative stress,endoplasmic reticulum stress,and fibrosis.The insights are expected to provide further understanding of the potential of MSCs in NAFLD therapeutics,and support the development of MSC-based therapy in the treatment of NAFLD.