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.

Protective Effects of Oyster Extract Against Hepatic Tissue Injury in Alcoholic Liver Diseases

Oyster extract is an effective bioactivity component. It has abundant nutritional value and antiviral, antitumor and im- mune defense fimctions. The role of oyster extract in treating liver injury has been paid more attention. We use Wistar rats to make alcoholic liver disease model through injecting alcohol into rats＇ stomachs. These rats were randomly divided into five groups： model group, control group, low-dose, middle-dose and high-dose experimental group with a dose of 0.12gkg-1, 0.40gkg-1, and 1.20gkg-1 alcoholic. After nine weeks, serum biomarkers （ALT, AST, TG and TCHO）, malondialdehyde （MDA）, glutathione （GSH）, C3a, CSa, IL-17, TNF-a, anti-MAA-HAS IgC~ CD3＋, CD4＋, CDS＋, NK cell activation and zinc content were assessed. The results showed that the serum biomarkers（ALT, AST, TG and TCHO）, MDA content, anti-MAA-HSA IgG, serum C3a, CSa IL-17 and TNF-a levels of oyster extract treatment groups were significantly decreased in comparison with model group. On the contrary, GSH showed ad- verse trend. Serum CD3＋, CD4＋ and NK cell activation were significantly increased in middle-dose group and high-dose group compared with model group, and there was decrease of CD8＋ activity in high-dose group. Plasma Zn level was decreased in model group compared with that in control group. Meanwhile, Mean plasma Zn levels increased dramatically following the dose increase of a given oyster extract.

New advances in molecular mechanisms and emerging therapeutic targets in alcoholic liver diseases

Alcoholic liver disease is a major health problem in the United States and worldwide. Chronic alcohol consumption can cause steatosis, inflammation, fibrosis, cirrhosis and even liver cancer. Significant progress has been made to understand key events and molecular players for the onset and progression of alcoholic liver disease from both experimental and clinical alcohol studies. No successful treatments are currently available for treating alcoholic liver disease; therefore, development of novel pathophysiological-targeted therapies is urgently needed. This review summarizes the recent progress on animal models used to study alcoholic liver disease and the detrimental factors that contribute to alcoholic liver disease pathogenesis including miRNAs, S-adenosylmethionine, Zinc deficiency, cytosolic lipin-1β, IRF3-mediated apoptosis, RIP3-mediated necrosis and hepcidin. In addition, we summarize emerging adaptive protective effects induced by alcohol to attenuate alcohol-induced liver pathogenesis including FoxO3, IL-22, autophagy and nuclear lipin-1α.

Significance of gut microbiota in alcoholic and non-alcoholic fatty liver diseases

Liver-gut communication is vital in fatty liver diseases,and gut microbes are the key regulators in maintaining liver homeostasis.Chronic alcohol abuse and persistent overnutrition create dysbiosis in gut ecology,which can contribute to fatty liver disease.In this review,we discuss the gut microbial compositional changes that occur in alcoholic and nonalcoholic fatty liver diseases and how this gut microbial dysbiosis and its metabolic products are involved in fatty liver disease pathophysiology.We also summarize the new approaches related to gut microbes that might help in the diagnosis and treatment of fatty liver disease.

Inflammation and fibrosis in chronic liver diseases including nonalcoholic fatty liver disease and hepatitis C

At present chronic liver disease(CLD),the third commonest cause of premature death in the United Kingdom is detected late,when interventions are ineffective,resulting in considerable morbidity and mortality.Injury to the liver,the largest solid organ in the body,leads to a cascade of inflammatory events.Chronic inflammation leads to the activation of hepatic stellate cells that undergo transdifferentiation to become myofibroblasts,the main extra-cellular matrix producing cells in the liver;over time increased extra-cellular matrix production results in the formation of liver fibrosis.Although fibrogenesis may be viewed as having evolved as a“wound healing”process that preserves tissue integrity,sustained chronic fibrosis can become pathogenic culminating in CLD,cirrhosis and its associated complications.As the reference standard for detecting liver fibrosis,liver biopsy,is invasive and has an associated morbidity,the diagnostic assessment of CLD by non-invasive testing is attractive.Accordingly,in this review the mechanisms by which liver inflammation and fibrosis develop in chronic liver diseases are explored to identify appropriate and meaningful diagnostic targets for clinical practice.Due to differing disease prevalence and treatment efficacy,disease specific diagnostic targets are required to optimally manage individual CLDs such as non-alcoholic fatty liver disease and chronic hepatitis C infection.To facilitate this,a review of the pathogenesis of both conditions is also conducted.Finally,the evidence for hepatic fibrosis regression and the mechanisms by which this occurs are discussed,including the current use of antifibrotic therapy.

Intestinal virome:An important research direction for alcoholic and nonalcoholic liver diseases

In recent years,the interaction between the gut microflora and liver diseases has attracted much attention.The intestinal microflora is composed of bacteria,archaea,fungi and viruses.There are few studies on the intestinal virome,and whether it has a causal relationship with bacterial changes in the gut is still unclear.However,it is undeniable that the intestinal virome is also a very important portion of the blueprint for the development of liver diseases and the diagnosis and therapeutic modalities in the future.

Mechanism and therapeutic strategy of hepatic TM6SF2-deficient non-alcoholic fatty liver diseases via in vivo and in vitro experiments

BACKGROUND The lack of effective pharmacotherapies for nonalcoholic fatty liver disease(NAFLD)is mainly attributed to insufficient research on its pathogenesis.The pathogenesis of TM6SF2-efficient NAFLD remains unclear,resulting in a lack of therapeutic strategies for TM6SF2-deficient patients.AIM To investigate the role of TM6SF2 in fatty acid metabolism in the context of fatty liver and propose possible therapeutic strategies for NAFLD caused by TM6SF2 deficiency.METHODS Liver samples collected from both NAFLD mouse models and human participants(80 cases)were used to evaluate the expression of TM6SF2 by using western blotting,immunohistochemistry,and quantitative polymerase chain reaction.RNA-seq data retrieved from the Gene Expression Omnibus database were used to confirm the over-expression of TM6SF2.Knockdown and overexpression of TM6SF2 were performed to clarify the mechanistic basis of hepatic lipid accumulation in NAFLD.MK-4074 administration was used as a therapeutic intervention to evaluate its effect on NAFLD caused by TM6SF2 deficiency.RESULTS Hepatic TM6SF2 levels were elevated in patients with NAFLD and NAFLD mouse models.TM6SF2 overexpression can reduce hepatic lipid accumulation,suggesting a protective role for TM6SF2 in a high-fat diet(HFD).Downregulation of TM6SF2,simulating the TM6SF2 E167K mutation condition,increases intracellular lipid deposition due to dysregulated fatty acid metabolism and is characterized by enhanced fatty acid uptake and synthesis,accompanied by impaired fatty acid oxidation.Owing to the potential effect of TM6SF2 deficiency on lipid metabolism,the application of an acetyl-CoA carboxylase inhibitor(MK-4074)could reverse the NAFLD phenotypes caused by TM6SF2 deficiency.CONCLUSION TM6SF2 plays a protective role in the HFD condition;its deficiency enhanced hepatic lipid accumulation through dysregulated fatty acid metabolism,and MK-4074 treatment could alleviate the NAFLD phenotypes caused by TM6SF2 deficiency.

Protection effect of trigonelline on liver of rats with non-alcoholic fatty liver diseases

Objective: To study the effect of trigonelline on the change of indicators of serum transaminase, lipoprotein and liver lipid of model rats with non-alcoholic fatty liver diseases and on the expression level of Bcl-2 and Bax proteins. Methods: A total of 45 SD rats were randomly divided into Fthe control group, model group and trigonelline intervention group. Rats in the control group were fed with the common diet, while rats in the model group and intervention group were fed with the high fat diet. 8 weeks later, the intervention group received the intragastric administration of trigonellin e(with the dosage of 40 mg/kg/d) for 8 weeks; while control group and model group received the intragastric administration of saline with the equal dosage. Blood was taken from the abdominal aorta of rats 8 weeks later, detecting the level of a series of indicators of ALT, AST, TG, TC, HDL-C and LDL-C in the serum. After the rats were sacrificed, detect the indicators of TG, TC, SOD and MDA in the liver tissue of rats, as well as the expression of Bcl-2 and Bax in the liver tissue. Results: Results of histopathologic examination showed that the damage degree of liver for rats in the trigonellineintervention group was smaller than the one in the model group, with significantly reduced hepatic steatosis and the partially visible hepatic lobule. The levels of ALT, AST, TC and LDL-C in the serum of rats in the trigonelline group were significantly reduced, while the change in the levels of TG and HDL-C was not significantly different. The levels of TG, TC and MDA in the liver tissues were significantly decreased, while the level of SOD significantly increased; the expression of Bcl-2 protein in the liver tissues of rats in the trigonelline intervention group was significantly increased, while the expression of Bax protein significantly decreased. Conclusions: The trigonelline contributes to the therapeutic effect of non-alcoholic fatty liver diseases. It can also increase the expression of Bcl-2 protein and decrease the expression of Bax protein in the liver tissues, which can protect the liver.

Liver transplantation for pediatric inherited metabolic liver diseases

Liver transplantation(LT)remains the gold standard treatment for end stage liver disease in the pediatric population.For liver based metabolic disorders(LBMDs),the decision for LT is predicated on a different set of paradigms.With improved outcomes post-transplantation,LT is no longer merely life saving,but has the potential to also significantly improve quality of life.This review summarizes the clinical presentation,medical treatment and indications for LT for some of the common LBMDs.We also provide a practical update on the dilemmas and controversies surrounding the indications for transplantation,surgical considerations and prognosis and long terms outcomes for pediatric LT in LBMDs.Important progress has been made in understanding these diseases in recent years and with that we outline some of the new therapies that have emerged.

Pediatric metabolic liver diseases:Evolving role of liver transplantation

Metabolic liver diseases(MLD)are the second most common indication for liver transplantation(LT)in children.This is based on the fact that the majority of enzymes involved in various metabolic pathways are present within the liver and LT can cure or at least control the disease manifestation.LT is also performed in metabolic disorders for end-stage liver disease,its sequelae including hepatocellular cancer.It is also performed for preventing metabolic crisis’,arresting progression of neurological dysfunction with a potential to reverse symptoms in some cases and for preventing damage to end organs like kidneys as in the case of primary hyperoxalosis and methyl malonic acidemia.Pathological findings in explant liver with patients with metabolic disease include unremarkable liver to steatosis,cholestasis,inflammation,variable amount of fibrosis,and cirrhosis.The outcome of LT in metabolic disorders is excellent except for patients with mitochondrial disorders where significant extrahepatic involvement leads to poor outcomes and hence considered a contraindication for LT.A major advantage of LT is that in the post-operative period most patients can discontinue the special formula which they were having prior to the transplant and this increases their well-being and improves growth parameters.Auxiliary partial orthotopic LT has been described for patients with noncirrhotic MLD where a segmental graft is implanted in an orthotopic position after partial resection of the native liver.The retained native liver can be the potential target for future gene therapy when it becomes a clinical reality.

A key problem and challenge for hepatology:Obesity-related metabolic liver diseases

With the arrival of the new millennium,gastroenterologists have been faced with the problem of metabolic liver diseases associated with obesity.The active role of the liver in metabolism and inflammation make it a key organ in the war against the rapidly-spreading worldwide epidemic of obesity.Many lives and much money could be saved if the work of hepatologists led to the development of effective diagnostic and therapeutic strategies against this growing leader of cirrhosis.

PTEN in liver diseases and cancer

The phosphoinositide 3-kinase (PI3K)/phosphatase and tensin homolog (PTEN)/Akt axis is a key signal transduction node that regulates crucial cellular functions, including insulin and other growth factors signaling, lipid and glucose metabolism, as well as cell survival and apoptosis. In this pathway, PTEN acts as a phosphoinositide phosphatase, which terminates PI3Kpropagated signaling by dephosphorylating PtdIns(3,4)P2 and PtdIns(3,4,5)P3. However, the role of PTEN does not appear to be restricted only to PI3K signaling antagonism, and new functions have been recently discovered for this protein. In addition to the well-established role of PTEN as a tumor suppressor, increasing evidence now suggests that a dysregulated PTEN expression and/or activity is also linked to the development of several hepatic pathologies. Dysregulated PTEN expression/activity is observed with obesity, insulin resistance, diabetes, hepatitis B virus/hepatitis C virus infections, and abusive alcohol consumption, whereas mutations/deletions have also been associated with the occurrence of hepatocellular carcinoma. Thus, it appears that alterations of PTEN expression and activity in hepatocytes are common and recurrent molecular events associated with liver disorders of various etiologies. These recent f indings suggest that PTEN might represent a potential common therapeutic target for a number of liver pathologies.

Epidemiological and histopathological study of relevance of Guizhou Maotai liquor and liver diseases

AIM: To explore the relevance of Maotai liquor and liver diseases. METHODS: Epidemiological study was conducted on groups of subjects, each consisting of 3 subjects from the Maotai liquor group consisting of 99 individuals and one from the non-alcoholic control group consisting of 33 individuals. Liver biopsy was performed on 23 volunteers from Guizhou Maotai Distillery who had a constant and long history of drinking Maotai liquor. Experimental histopathological study was conducted as follows: sixty male Wistar rats were divided into 3 groups randomly and fed with Maotai liquor, ordinary white wine, and physiological saline respectively for a period of 8 and 12 weeks. The rats were sacrificed in batches, then serum ALT, AST, TBil, and AKP were measured. Rat livers were harvested to measure the liver indexes, GSH, and MDA. Histopathological examinations were also performed. Another eighty mice were randomly divided into 4 groups and fed with Maotai (at different dosages of 10 ml.kg(-1) and 20 ml.kg(-1)), ethanol, and physiological saline. The animals were sacrificed after 4 weeks and serum ALT was determined. Then the livers were harvested and liver indexes and MDA were measured. RESULTS: The incidence rate of hepatic symptoms, splenomegaly, liver function impairment, reversal of Albumin/Globulin and increased diameter of portal veins in the Maotai liquor group were 1.0% 1/99 , 1.0% 1/99 , 1.0% 1/99 , 1.0% 1/99 , 0 0/99 and 0 0/99 , 0 0/99 ,0 0/99 , 0 0/99 , 0 0/99 , respectively. There was no significant difference between the Maotai group and the non-alcoholic control group P】0.05 . Various degree of fatty infiltration of hepatocytes was found in the 23 volunteers receiving liver biopsy, but there was no obvious hepatic fibrosis or cirrhosis. A comparison was made between the Maotai liquor group and the ordinary white wine group. It was found that hepatic MDA in rats and mice were 0.33+/-0.10 and 0.49+/-0.23 respectively in Maotai group and 0.61+/-0.22 and 0.66+/-0.32 in the ordinary white wine group; MDA had an obvious decrease in the Maotai liquor group (P【0.05); hepatic GSH were 0.12 mg.g(-1)+/-0.06 mg.g(-1) in rats of the Maotai liquor group and (0.08+/-0.02)mg.g(-1) in white wine group, it was obviously increased in the Maotai liquor group (P【0.05). After the 20 rats had been fed with ordinary white wine for 8 weeks consecutively, disarranged hepatocyte cords, fatty infiltration of hepatocytes, and fibrous septa of varying widths due to hepatic connective tissues proliferation were observed; after 12 weeks, the fibrous tissue proliferation continued and early cirrhosis appeared. Compared with the ordinary white wine group, fatty infiltration was observed in the 8-week and 12-week groups, but no necrosis or fibrosis or cirrhosis was found in the Maotai liquor group (P【0.05). CONCLUSION: Maotai liquor may cause fatty liver but not hepatic fibrosis or cirrhosis, and it can strengthen lipid peroxidation in the liver.

COVID-19 and liver diseases,what we know so far

Coronavirus disease 2019(COVID-19)pneumonia outbreak started in December 2019.On March 12,2020,the World Health Organization(WHO)declared that the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)constitutes a pandemic,and as of May 2021,SARS-CoV-2 has infected over 167.3 million patients,including 3.4 million deaths,reported to WHO.In this review,we will focus on the relationship between SARS-CoV-2 infection and the liver.We will discuss how chronic liver diseases affect the COVID-19 disease course and outcomes.We will also discuss the SARS-CoV-2 effects on the liver,mechanisms of acute liver injury,and potential management plans.

Gut microbiota and liver diseases

Several studies revealed that gut microbiota are associated with various human diseases,e.g.,metabolic diseases,allergies,gastroenterological diseases,and liver diseases.The liver can be greatly affected by changes in gut microbiota due to the entry of gut bacteria or their metabolites into the liver through the portal vein,and the liver-gut axis is important to understand the pathophysiology of several liver diseases,especially non-alcoholic fatty liver disease and hepatic encephalopathy.Moreover,gut microbiota play a significant role in the development of alcoholic liver disease and hepatocarcinogenesis.Based on theseprevious findings,trials using probiotics have been performed for the prevention or treatment of liver diseases.In this review,we summarize the current understanding of the changes in gut microbiota associated with various liver diseases,and we describe the therapeutic trials of probiotics for those diseases.

Gender specific medicine in liver diseases:a point of view

Gender medicine focuses on the patho-physiological, clinical, prevention and treatment differences in diseases that are equally represented in men and women. The purpose of gender medicine is to ensure that each individual man and woman receives the best treatment possible based on scientific evidence. The concept of “gender” includes not only the sexual characteristics of individuals but also physiological and psychological attributes of men and women, including risk factors, protective/aggravating effects of sexual hormones and variances linked to genetics and corporal structures that explain biological and physiological differences between men and women. It is very important to consider all the biological, physiological, functional, psychological, social and cultural characteristics to provide patients with individualized disease management. Herein, we critically analyze the literature regarding gender differences for diseases and acquired conditions of the most representative hepatic pathologies: primary biliary cirrhosis, autoimmune hepatitis, primary sclerosing cholangitis, non alcoholic fatty liver disease and alcoholic liver disease, and viral chronic hepatitis B and C. The last section addresses hemochromatosis, which is a prevalent iron overload disorder in the Caucasian population. This review aims to describe data from the literature concerning viral chronic hepatitis during pregnancy, management during pregnancy and delivery, and new effective drugs for the prevention of maternal infection transmission without significant adverse effects or complications.

Steatosis as a co-factor in chronic liver diseases

The finding of lipid accumulation in the liver, so-called hepatic steatosis or non-alcoholic fatty liver disease, is a common condition frequently found in healthy subjects. Its prevalence, in fact, has been estimated by magnetic resonance studies to be about 35% in the general population and 75% in obese persons. Nevertheless, its presence generates liver damage only in a small percentage of subjects not affected by other liver diseases. It should be defined as a "co-factor" capable of affecting severity and progression, and also therapeutic perspectives, of liver diseases to which it is associated. Herein we will evaluate the impact of hepatic steatosis and obesity on the most common liver diseases: chronic viral hepatitis C and B, and alcoholic liver disease.

Role of inflammatory response in liver diseases: Therapeutic strategies

Inflammation and tumorigenesis are tightly linked pathways impacting cancer development. Inflammasomes are key signalling platforms that detect pathogenic microorganisms, including hepatitis C virus(HCV) infection, and sterile stressors(oxidative stress, insulin resistance, lipotoxicity) able to activate pro-inflammatory cytokines interleukin-1β and IL-18. Most of the inflammasome complexes that have been described to date contain a NOD-like receptor sensor molecule. Redox state and autophagy can regulate inflammasome complex and, depending on the conditions, can be either pro-or antiapoptotic. Acute and chronic liver diseases are cytokinedriven diseases as several proinflammatory cytokines(IL-1α, IL-1β, tumor necrosis factor-alpha, and IL-6) are critically involved in inflammation, steatosis, fibrosis, and cancer development. NLRP3 inflammasome gain of function aggravates liver disease, resulting in severe liver fibrosis and highlighting this pathway in the pathogenesis of non-alcoholic fatty liver disease. On the other hand, HCV infection is the primary catalyst for progressive liver disease and development of liver cancer. It is well established that HCV-induced IL-1β production by hepatic macrophages plays a critical and central process that promotes liver inflammation and disease. In this review, we aim to clarify the role of the inflammasome in the aggravation of liver disease, and how selective blockade of this main pathway may be a useful strategy to delay fibrosis progression in liver diseases.

Imaging characteristics of hypervascular focal nodular hyperplasialike lesions in patients with chronic alcoholic liver disease

BACKGROUND Focal nodular hyperplasia(FNH)-like lesions are hyperplastic formations in patients with micronodular cirrhosis and a history of alcohol abuse.Although pathologically similar to hepatocellular carcinoma(HCC)lesions,they are benign.As such,it is important to develop methods to distinguish between FNH-like lesions and HCC.AIM To evaluate diagnostically differential radiological findings between FNH-like lesions and HCC.METHODS We studied pathologically confirmed FNH-like lesions in 13 patients with alco-holic cirrhosis[10 men and 3 women;mean age:54.5±12.5(33-72)years]who were negative for hepatitis-B surface antigen and hepatitis-C virus antibody and underwent dynamic computed tomography(CT)and magnetic resonance imaging(MRI),including superparamagnetic iron oxide(SPIO)and/or gadoxetic acid-enhanced MRI.Seven patients also underwent angiography-assisted CT.RESULTS The evaluated lesion features included arterial enhancement pattern,washout appearance(low density compared with that of surrounding liver parenchyma),signal intensity on T1-weighted image(T1WI)and T2-weighted image(T2WI),central scar presence,chemical shift on in-and out-of-phase images,and uptake pattern on gadoxetic acid-enhanced MRI hepatobiliary phase and SPIO-enhanced MRI.Eleven patients had multiple small lesions(<1.5 cm).Radiological features of FNH-like lesions included hypervascularity despite small lesions,lack of“corona-like”enhancement in the late phase on CT during hepatic angiography(CTHA),high-intensity on T1WI,slightly high-or iso-intensity on T2WI,no signal decrease in out-of-phase images,and complete SPIO uptake or incomplete/partial uptake of gadoxetic acid.Pathologically,similar to HCC,FNH-like lesions showed many unpaired arteries and sinusoidal capillarization.CONCLUSION Overall,the present study showed that FNH-like lesions have unique radiological findings useful for differential diagnosis.Specifically,SPIO-and/or gadoxetic acid-enhanced MRI and CTHA features might facilitate differential diagnosis of FNH-like lesions and HCC.

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.