Asperosaponin VI protects alcohol-induced hepatic steatosis and injury via regulating lipid metabolism and ER stress.

BACKGROUND: Asperosaponin VI (AVI) is a natural triterpenoid saponin isolated from Dipsacus asper Wall with documented anti-inflammatory and bone protective effects. Our previous work reported that AVI protects the liver of septic mice from acute inflammatory damage. In this paper, we further explored the protective effect and the potential mechanisms of AVI in alcoholic fatty liver disease (AFLD). METHODS: The Lieber-Decarli model was constructed to evaluate the effect of AVI on AFLD in C57BL/6 J mice. Additional in vitro work was performed to investigate HepG2 cells exposed to alcohol, then analyzed the degree of liver injury by detecting the ALT and AST levels both in the liver and serum. H&E staining and Sirius red staining were used to evaluate the histopathology variations in the liver. Further, observe lipid droplets in the cytoplasm by Oil Red O staining. We detected the expression of inflammatory cytokines with qualitative PCR; ROS, MDA, SOD, and GSH-px levels were analyzed to observe oxidative stress. Finally, exploring the activation of AMPK signaling pathway by real-time PCR and Western blotting. RESULTS: Histological examination of liver tissue combined with serum ALT and AST levels showed a significant protective effect of AVI against alcoholic liver injury in AFLD mice. Compared with the model group, AVI evidently improved antioxidant capacity, reduced inflammatory response and lipid accumulation both in vitro and in vivo. For mechanically, it was found that AVI up-regulated phosphorylation level of AMP-activated protein kinase (AMPK) and inhibited the endoplasmic reticulum stress (ER) pathway in AFLD. CONCLUSION: AVI protects mice from alcohol-induced hepatic steatosis and liver injury through activating AMPK signaling and repress ER stress, suggesting that it might be a potential therapeutic agent for AFLD.

FBXL5 promotes lipid accumulation in alcoholic fatty liver disease by promoting the ubiquitination and degradation of TFEB.

BACKGROUND: Alcoholic fatty liver disease (AFLD) is characterized by abnormal lipid droplet accumulation in liver. Epigenetic regulation plays an important role in the pathogenesis of AFLD. Comprehensive bioinformatics analysis revealed that an E3 ubiquitin ligase, F-box and leucine-rich repeats protein 5 (FBXL5), was significantly upregulated in AFLD mice. METHODS: The mouse model of AFLD was established by feeding Lieber-DeCarli liquid diet containing ethanol. An in vitro model of AFLD was established by treating HepG2 cells with ethanol (EtOH). The FBXL5 expression was assessed by quantitative real-time PCR (qRT-PCR) and western blotting assays. The levels of triglyceride (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lipid accumulation were analyzed by enzyme-linked immunosorbent assay (ELISA) and Nile red staining. RESULTS: The FBXL5 expression was markedly up-regulated in in vivo and in vitro models of AFLD compared with controls. Functionally, FBXL5 knockdown alleviated lipid accumulation in EtOH-treated HepG2 cells. Mechanistically, FBXL5 directly interacted with transcription factor EB (TFEB) and accelerated its ubiquitination-mediated degradation. TFEB knockdown reversed the effect of FBXL5 inhibition on decreasing EtOH-induced lipid accumulation. CONCLUSION: Our data suggest that FBXL5 promotes lipid accumulation in AFLD by promoting the ubiquitination and degradation of TFEB.

Metabolic signature of HepaRG cells exposed to ethanol and tumor necrosis factor alpha to study alcoholic steatohepatitis by LC-MS-based untargeted metabolomics.

Despite the high prevalence of alcoholic liver disease, its identification and characterization remain poor, especially in early stages such as alcoholic fatty liver disease and alcoholic steatohepatitis. This latter implies diagnostic difficulties, few therapeutic options and unclear mechanisms of action. To elucidate the metabolic alterations and pinpoint affected biochemical pathways, alcoholic steatohepatitis was simulated in vitro by exposing HepaRG cells to ethanol (IC10, 368 mM) and tumor necrosis factor alpha (TNF-α, 50 ng/mL) for 24 h. This combined exposure was compared to solely ethanol-exposed as well as -nonexposed cells. Four different metabolomics platforms were used combining liquid chromatography, high-resolution mass spectrometry and drift tube ion mobility to elucidate both intracellular and extracellular metabolic alterations. Some of the key findings include the influence of TNF-α in the upregulation of hepatic triglycerides and the downregulation of hepatic phosphatidylethanolamines and phosphatidylcholines. S-Adenosylmethionine showed to play a central role in the progression of alcoholic steatohepatitis. In addition, fatty acyl esters of hydroxy fatty acid (FAHFA)-containing triglycerides were detected for the first time in human hepatocytes and their alterations showed a potentially important role during the progression of alcoholic steatohepatitis. Ethoxylated phosphorylcholine was identified as a potential new biomarker of ethanol exposure.

Deficiency of NLR family member NLRC5 alleviates alcohol induced hepatic injury and steatosis by enhancing autophagy of hepatocytes.

Steatosis is regarded as an early response of the liver to excessive alcohol consumption, which ultimately results in alcoholic liver disease (ALD). Hepatocytes are the primary drivers of the pathological process known as hepatic damage and steatosis, which is characterized by significant fat accumulation and an abundance of fat vacuoles. NLRs, a family member of pattern recognition receptors, have recently been found to be crucial in liver disorders. In this study, we examined the possible impact of NLRC5, the largest NLR family member, on alcohol-induced fatty liver development using a gene knock-out mouse model. The mouse liver was severely damaged and developed steatosis as a result of chronic and excessive ethanol use, and this damage was prevented by the lack of NLRC5. Additionally, NLRC5 deletion reversed ethanol's ability to increase the serum concentrations of TG, T-CHO, ALT, and AST. Absence of NLRC5 reduced ethanol-stimulated aberrant expression of the vital regulators of lipid synthesis and metabolism, SREBP-1c, FAS and PPAR-α. Furthermore, loss- and gain-of-function research indicated that NLRC5 might affect the autophagy pathway in alcohol-induced hepatic steatosis progression. The functional role of NLRC5 in ALD is obviously impacted by the autophagy inducer rapamycin as well as the autophagy inhibitor 3-MA. Our research showed that NLRC5 was involved in ethanol-induced injury and steatosis of the liver, and may be considered a suitable therapeutic target for treating ALD.

Downregulating PDPK1 and taking phillyrin as PDPK1-targeting drug protect hepatocytes from alcoholic steatohepatitis by promoting autophagy.

The health risk stemming from drinking alcohol is serious, sometimes even life-threatening. Alcoholic steatohepatitis (ASH) is a critical stage leading to cirrhosis and end-stage liver disease. However, its pathogenesis is still far from clearly understood, and a treatment that is widely recognised as effective has not been discovered. Interestingly, PDPK1,3-phosphoinositide-dependent protein kinase 1, also known as PDK1, was observed to be obviously increased in the ASH model by our researchers. We also investigated the protective role of autophagy in ASH. Here, we studied the function of PDPK1 and found an efficient treatment to alleviate symptoms by targeting PDPK1 in ASH. In our study, PDPK1 affected hepatocyte self-healing by inhibiting autophagy. Both inhibiting PDPK1 and the phosphorylation of PDPK1 (ser241) could protect hepatocytes from suffering heavy alcoholic hepatitis.

The Anti-Adiposity Mechanisms of Ampelopsin and Vine Tea Extract in High Fat Diet and Alcohol-Induced Fatty Liver Mouse Models.

Ampelopsis grossedentata (AG) is an ancient medicinal plant that is mainly distributed and used in southwest China. It exerts therapeutic effects, such as antioxidant, anti-diabetic, and anti-inflammatory activities, reductions in blood pressure and cholesterol and hepatoprotective effects. Researchers in China recently reported the anti-obesity effects of AG extract in diet-induced obese mice and rats. To verify these findings, we herein investigated the effects of AG extract and its principal compound, ampelopsin, in high-fat diet (HFD)- and alcohol diet-fed mice, olive oil-loaded mice, and differentiated 3T3-L1 cells. The results obtained showed that AG extract and ampelopsin significantly suppressed increases in the weights of body, livers and abdominal fat and also up-regulated the expression of carnitine palmitoyltransferase 1A in HFD-fed mice. In olive oil-loaded mice, AG extract and ampelopsin significantly attenuated increases in serum triglyceride (TG) levels. In differentiated 3T3-L1 cells, AG extract and ampelopsin promoted TG decomposition, which appeared to be attributed to the expression of hormone-sensitive lipase. In alcohol diet-fed mice, AG extract and ampelopsin reduced serum levels of ethanol, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) and liver TG. An examination of metabolic enzyme expression patterns revealed that AG extract and ampelopsin mainly enhanced the expression of aldehyde dehydrogenase and suppressed that of cytochrome P450, family 2, subfamily e1. In conclusion, AG extract and ampelopsin suppressed diet-induced intestinal fat accumulation and reduced the risk of fatty liver associated with HFD and alcohol consumption.

Crosstalk between Oxidative Stress and Inflammatory Liver Injury in the Pathogenesis of Alcoholic Liver Disease.

Alcoholic liver disease (ALD) is characterized by the injury, inflammation, and scarring in the liver owing to excessive alcohol consumption. Currently, ALD is a leading cause for liver transplantation. Therefore, extensive studies (in vitro, in experimental ALD models and in humans) are needed to elucidate pathological features and pathogenic mechanisms underlying ALD. Notably, oxidative changes in the liver have been recognized as a signature trait of ALD. Progression of ALD is linked to the generation of highly reactive free radicals by reactions involving ethanol and its metabolites. Furthermore, hepatic oxidative stress promotes tissue injury and, in turn, stimulates inflammatory responses in the liver, forming a pathological loop that promotes the progression of ALD. Accordingly, accumulating further knowledge on the relationship between oxidative stress and inflammation may help establish a viable therapeutic approach for treating ALD.

Development of a Scoring System to Differentiate Amiodarone-Induced Liver Injury From Alcoholic Steatohepatitis.

OBJECTIVES: Amiodarone-induced liver injury (AILI) is histopathologically similar to alcoholic steatohepatitis (ASH). We sought to elucidate their histologic differences and develop a scoring system to differentiate these two entities. METHODS: A cohort of 17 AILI and 17 ASH cases was included in the initial study. Cases from three different institutions were included for further validation. RESULTS: Macrovesicular steatosis was usually below 10% of the liver parenchyma in AILI. Hepatocyte ballooning degeneration was more common in ASH than in AILI. "Balloon-like" hepatocyte was more common in AILI than in ASH. Lobular neutrophilic inflammation, satellitosis, and cholestasis were more common in ASH. Mallory-Denk bodies and pericellular fibrosis in AILI were mainly located in zone 1 compared with a panacinar or zone 3 distribution in ASH. A scoring system was developed in which points were assigned to different histologic features; a total sum of less than 5 suggests AILI, more than 5 is ASH, and 5 is equivocal. This scoring system was then evaluated on a test cohort comprising 14 AILI cases, in which 13 cases were correctly assigned with a score less than 5. The sensitivity, specificity, and accuracy for diagnosing AILI in the test cohort were 92.9%, 91.7%, and 92.3%, respectively. CONCLUSIONS: This scoring system can aid pathologists to differentiate AILI from ASH.

ZFP36L1 Regulates Fgf21 mRNA Turnover and Modulates Alcoholic Hepatic Steatosis and Inflammation in Mice.

Zinc finger protein 36 like 1 (ZFP36L1) enhances the turnover of mRNAs containing AU-rich elements (AREs) in their 3'-untranslated regions (3'UTR). The physiological and pathological functions of ZFP36L1 in liver, however, remain largely unknown. Liver-specific ZFP36L1-deficient (Zfp36l1flox/flox/Cre+; L1LKO) mice were generated to investigate the role of ZFP36L1 in liver physiology and pathology. Under normal conditions, the L1LKO mice and their littermate controls (Zfp36l1flox/flox/Cre-; L1FLX) appeared normal. When fed a Lieber-DeCarli liquid diet containing alcohol, L1LKO mice were significantly protected from developing alcohol-induced hepatic steatosis, injury, and inflammation compared with L1FLX mice. Most importantly, fibroblast growth factor 21 (Fgf21) mRNA was significantly increased in the livers of alcohol diet-fed L1LKO mice compared with the alcohol diet-fed L1FLX group. The Fgf21 mRNA contains three AREs in its 3'UTR, and Fgf21 3'UTR was directly regulated by ZFP36L1 in luciferase reporter assays. Steady-state levels of Fgf21 mRNA were significantly decreased by wild-type ZFP36L1, but not by a non-binding zinc finger ZFP36L1 mutant. Finally, wild-type ZFP36L1, but not the ZFP36L1 mutant, bound to the Fgf21 3'UTR ARE RNA probe. These results demonstrate that ZFP36L1 inactivation protects against alcohol-induced hepatic steatosis and liver injury and inflammation, possibly by stabilizing Fgf21 mRNA. These findings suggest that the modulation of ZFP36L1 may be beneficial in the prevention or treatment of human alcoholic liver disease.

Metabolic and Genetic Risk Factors Are the Strongest Predictors of Severity of Alcohol-Related Liver Fibrosis.

BACKGROUND & AIMS: Individual risk for developing alcohol-related liver disease (ALD) varies greatly. We hypothesized that metabolic risk factors and genetic polymorphisms predict severity of ALD. METHODS: Biopsy-controlled, cross-sectional study in patients with a history of excessive drinking. We measured the homeostatic model assessment of insulin resistance (HOMA-IR), plasma triglycerides, high- and low-density lipoproteins (HDL, LDL), and total cholesterol. Moreover, we genotyped four single nucleotide polymorphisms in PNPLA3 (rs738409C>G), TM6SF2 (rs58542926C>T), MBOAT7 (rs641738C>T), and HSD17B13 (rs72613567T>TA). We assessed predictors of higher fibrosis stage using multivariable ordered logistic regression. RESULTS: Of 325 included patients, 25% had severe fibrosis or cirrhosis and 59% had HOMA-IR ≥2.5. HOMA-IR increased for each fibrosis stage, while there was a similar decrease in LDL and total cholesterol. Individuals with risk variant PNPLA3 rs738409-G or TM6SF2 rs58542926-T had higher fibrosis stage. In multivariable regression, HOMA-IR ≥2.5 (OR = 3.04, 95% CI 1.90-4.87), LDL <2.60 mmol/L (OR = 2.05, 95% CI 1.33-3.16), TM6SF2 rs58542926-T (OR = 1.99, 95% CI 1.17-3.37), age above 50 years (OR = 1.66, 95% CI 1.03-2.70), and PNPLA3 rs738409-G (OR = 1.54, 95% CI 1.11-2.12) independently predicted higher fibrosis stage. Independent predictors of hepatic inflammatory activity were HOMA-IR, active drinking, age, and PNPLA3 risk variant. Active drinking, elevated triglycerides, and PNPLA3 risk variant predicted steatosis. CONCLUSIONS: Insulin resistance is the strongest predictor of liver fibrosis stage and hepatic inflammation in patients with alcohol-related liver disease. Genetic susceptibility further aggravates this risk. These data highlight the clinical value of detailed metabolic and genetic profiling of patients with excessive alcohol use.

Pathologic Diagnosis of Nonalcoholic Fatty Liver Disease.

CONTEXT.­: Nonalcoholic fatty liver disease (NAFLD) encompasses steatosis and steatohepatitis. The cause may be multifactorial, and diagnosis requires correlation with clinical information and laboratory results. OBJECTIVE.­: To provide an overview of the status of histology diagnosis of steatosis, steatohepatitis, and associated conditions. DATA SOURCES.­: A literature search was performed using the PubMed search engine. The terms ''steatosis,'' ''steatohepatitis,'' ''nonalcoholic fatty liver disease (NAFLD),'' ''nonalcoholic steatohepatitis (NASH),'' "alcoholic steatohepatitis (ASH)," ''type 2 diabetes (T2DM),'' "cryptogenic cirrhosis," "drug-induced liver injury (DILI)," "immune checkpoint inhibitor therapy," and "COVID-19 and liver" were used. CONCLUSIONS.­: Nonalcoholic fatty liver disease has become the most common chronic liver disease in the United States. NASH is the progressive form of nonalcoholic fatty liver disease. The hallmarks of steatohepatitis are steatosis, ballooned hepatocytes, and lobular inflammation. NASH and alcoholic steatohepatitis share similar histologic features, but some subtle differences may help their distinction. NASH is commonly seen in patients with metabolic dysfunction but can also be caused by other etiologies. Examples are medications including newly developed immune checkpoint inhibitors and viral infections such as coronavirus disease 2019 (COVID-19). NASH is also a common cause of cryptogenic cirrhosis but can be reversed. The results from recent clinical trials for NASH treatment are promising in reducing the severity of steatosis, ballooning, and fibrosis.

A Western diet with alcohol in drinking water recapitulates features of alcohol-associated liver disease in mice.

BACKGROUND: Mouse models of alcohol-associated liver disease vary greatly in their ease of implementation and the pathology they produce. Effects range from steatosis and mild inflammation with the Lieber-DeCarli liquid diet to severe inflammation, fibrosis, and pyroptosis seen with the Tsukamoto-French intragastric feeding model. Implementation of all of these models is limited by the labor-intensive nature of the protocols and the specialized skills necessary for successful intragastric feeding. We thus sought to develop a new model to reproduce features of alcohol-induced inflammation and fibrosis with minimal operational requirements. METHODS: Over a 16-week period, mice were fed ad libitum with a pelleted high-fat Western diet (WD; 40% calories from fat) and alcohol added to the drinking water. We found the optimal alcohol consumption to be that at which the alcohol concentration was 20% for 4 days and 10% for 3 days per week. Control mice received WD pellets with water alone. RESULTS: Alcohol consumption was 18 to 20 g/kg/day in males and 20 to 22 g/kg/day in females. Mice in the alcohol groups developed elevated serum transaminase levels after 12 weeks in males and 10 weeks in females. At 16 weeks, both males and females developed liver inflammation, steatosis, and pericellular fibrosis. Control mice on WD without alcohol had mild steatosis only. Alcohol-fed mice showed reduced HNF4α mRNA and protein expression. HNF4α is a master regulator of hepatocyte differentiation, down-regulation of which is a known driver of hepatocellular failure in alcoholic hepatitis. CONCLUSION: A simple-to-administer, 16-week WD alcohol model recapitulates the inflammatory, fibrotic, and gene expression aspects of human alcohol-associated steatohepatitis.

CYP2E1 in Alcoholic and Non-Alcoholic Liver Injury. Roles of ROS, Reactive Intermediates and Lipid Overload.

CYP2E1 is one of the fifty-seven cytochrome P450 genes in the human genome and is highly conserved. CYP2E1 is a unique P450 enzyme because its heme iron is constitutively in the high spin state, allowing direct reduction of, e.g., dioxygen, causing the formation of a variety of reactive oxygen species and reduction of xenobiotics to toxic products. The CYP2E1 enzyme has been the focus of scientific interest due to (i) its important endogenous function in liver homeostasis, (ii) its ability to activate procarcinogens and to convert certain drugs, e.g., paracetamol and anesthetics, to cytotoxic end products, (iii) its unique ability to effectively reduce dioxygen to radical species causing liver injury, (iv) its capability to reduce compounds, often generating radical intermediates of direct toxic or indirect immunotoxic properties and (v) its contribution to the development of alcoholic liver disease, steatosis and NASH. In this overview, we present the discovery of the enzyme and studies in humans, 3D liver systems and genetically modified mice to disclose its function and clinical relevance. Induction of the CYP2E1 enzyme either by alcohol or high-fat diet leads to increased severity of liver pathology and likelihood to develop ALD and NASH, with subsequent influence on the occurrence of hepatocellular cancer. Thus, fat-dependent induction of the enzyme might provide a link between steatosis and fibrosis in the liver. We conclude that CYP2E1 has many important physiological functions and is a key enzyme for hepatic carcinogenesis, drug toxicity and liver disease.

Depdc5 deficiency exacerbates alcohol-induced hepatic steatosis via suppression of PPARα pathway.

Alcohol-related liver disease (ALD), a condition caused by alcohol overconsumption, occurs in three stages of liver injury including steatosis, hepatitis, and cirrhosis. DEP domain-containing protein 5 (DEPDC5), a component of GAP activities towards Rags 1 (GATOR1) complex, is a repressor of amino acid-sensing branch of the mammalian target of rapamycin complex 1 (mTORC1) pathway. In the current study, we found that aberrant activation of mTORC1 was likely attributed to the reduction of DEPDC5 in the livers of ethanol-fed mice or ALD patients. To further define the in vivo role of DEPDC5 in ALD development, we generated Depdc5 hepatocyte-specific knockout mouse model (Depdc5-LKO) in which mTORC1 pathway was constitutively activated through loss of the inhibitory effect of GATOR1. Hepatic Depdc5 ablation leads to mild hepatomegaly and liver injury and protects against diet-induced liver steatosis. In contrast, ethanol-fed Depdc5-LKO mice developed severe hepatic steatosis and inflammation. Pharmacological intervention with Torin 1 suppressed mTORC1 activity and remarkably ameliorated ethanol-induced hepatic steatosis and inflammation in both control and Depdc5-LKO mice. The pathological effect of sustained mTORC1 activity in ALD may be attributed to the suppression of peroxisome proliferator activated receptor α (PPARα), the master regulator of fatty acid oxidation in hepatocytes, because fenofibrate (PPARα agonist) treatment reverses ethanol-induced liver steatosis and inflammation in Depdc5-LKO mice. These findings provide novel insights into the in vivo role of hepatic DEPDC5 in the development of ALD.

Elevated S-adenosylhomocysteine induces adipocyte dysfunction to promote alcohol-associated liver steatosis.

It has been previously shown that chronic ethanol administration-induced increase in adipose tissue lipolysis and reduction in the secretion of protective adipokines collectively contribute to alcohol-associated liver disease (ALD) pathogenesis. Further studies have revealed that increased adipose S-adenosylhomocysteine (SAH) levels generate methylation defects that promote lipolysis. Here, we hypothesized that increased intracellular SAH alone causes additional related pathological changes in adipose tissue as seen with alcohol administration. To test this, we used 3-deazaadenosine (DZA), which selectively elevates intracellular SAH levels by blocking its hydrolysis. Fully differentiated 3T3-L1 adipocytes were treated in vitro for 48 h with DZA and analysed for lipolysis, adipokine release and differentiation status. DZA treatment enhanced adipocyte lipolysis, as judged by lower levels of intracellular triglycerides, reduced lipid droplet sizes and higher levels of glycerol and free fatty acids released into the culture medium. These findings coincided with activation of both adipose triglyceride lipase and hormone sensitive lipase. DZA treatment also significantly reduced adipocyte differentiation factors, impaired adiponectin and leptin secretion but increased release of pro-inflammatory cytokines, IL-6, TNF and MCP-1. Together, our results demonstrate that elevation of intracellular SAH alone by DZA treatment of 3T3-L1 adipocytes induces lipolysis and dysregulates adipokine secretion. Selective elevation of intracellular SAH by DZA treatment mimics ethanol's effects and induces adipose dysfunction. We conclude that alcohol-induced elevations in adipose SAH levels contribute to the pathogenesis and progression of ALD.

Downregulation of long non-coding RNA AIRN promotes mitophagy in alcoholic fatty hepatocytes by promoting ubiquitination of mTOR.

Long non-coding RNAs (lncRNAs) are crucial in chronic liver diseases, but the specific molecular mechanism of lncRNAs in alcoholic fatty liver (AFL) remains unclear. In this study, we investigated the in-depth regulatory mechanism of mTOR affected by AIRN non-protein coding RNA (lncRNA-AIRN) in the development of AFL. LncRNA-AIRN was highly expressed in the liver tissues of AFL C57BL/6mice and oleic acid+alcohol (O+A)treated AML-12cells by using quantitative real-timePCR. RNA pull-down and RNA immunoprecipitation experiments demonstrated that there was an interaction between lncRNA-AIRN and mTOR, and that interference with lncRNA-AIRN could promote the mTOR protein level. Results ofcycloheximide-chase assay showed that the proteinlevel of mTOR was decreased with the treatment time after the knockdown of lncRNA-AIRN. Furthermore, the knockdown of lncRNA-AIRN reducedmTOR protein level by promoting the E3 ubiquitin ligase FBXW7-mediated ubiquitination.The lncRNA-AIRN/mTORaxis was involved in the regulation of the mitophagy of O+A treated hepatocytes, which was confirmed by the cell transfection and the MTT assay.SPSS 16.0 was used for analyzing data. The difference between the two groups was analyzed by performing Student's t-test, and ANOVA was used to analyze the difference when more than two groups. P values < 0.05 were considered to be significantly different.Our findings demonstrated that the knockdown of lncRNA-AIRN influencedmitophagy in AFL by promoting mTOR ubiquitination.

Alcoholic fatty liver disease inhibited the co-expression of Fmo5 and PPARα to activate the NF-κB signaling pathway, thereby reducing liver injury via inducing gut microbiota disturbance.

BACKGROUND: Alcohol-induced intestinal dysbiosis disrupts and inflammatory responses are essential in the development of alcoholic fatty liver disease (AFLD). Here, we investigated the effects of Fmo5 on changes in enteric microbiome composition in a model of AFLD and dissected the pathogenic role of Fmo5 in AFLD-induced liver pathology. METHODS: The expression profile data of GSE8006 and GSE40334 datasets were downloaded from the GEO database. The WGCNA approach allowed us to investigate the AFLD-correlated module. DEGs were used to perform KEGG pathway enrichment analyses. Four PPI networks were constructed using the STRING database and visualized using Cytoscape software. The Cytohubba plug-in was used to identify the hub genes. Western blot and immunohistochemistry assays were used to detect protein expression. ELISA assay was used to detect the levels of serum inflammatory cytokines. Lipid droplets in the cytoplasm were observed using Oil Red O staining. Apoptosis was detected using a TUNEL assay and flow cytometry analysis. ROS levels were detected using flow cytometry analysis. Nuclear translocation of NF-κB p65 was observed using immunofluorescence staining. Co-immunoprecipitation was used to detect the co-expression of PPARα and Fmo5 in L02 cells. 16S rDNA sequencing defined the bacterial communities in mice with AFLD. RESULTS: Fmo5 is a key DEG and is closely associated with the gut microbiota and PPAR signaling pathway. Gut microbiome function in AFLD was significantly related to the PPAR signaling pathway. AFLD induced shifts in various bacterial phyla in the cecum, including a reduction in Bacteroidetes and increased Firmicutes. Fmo5 and PPARα co-expression in cell and animal models with AFLD, which decreased significantly. Silencing of Fmo5 and PPARα aggravated the functions of AFLD inducing apoptosis and inflammatory response, promoting liver injury, and activating the NF-κB signaling pathway in vivo and in vitro. The NF-κB inhibitor abolished the functions of silencing of Fmo5 and PPARα promoting AFLD-induced apoptosis, inflammatory response, and liver injury. CONCLUSION: Our data indicated that the co-expression of Fmo5 and PPARα was involved in AFLD-related gut microbiota composition and alleviated AFLD-induced liver injury, apoptosis, and inflammatory response by inhibiting the nuclear translocation of NF-κB p65 to inhibit the NF-κB signaling pathway.

Effects of Different Green Tea Extracts on Chronic Alcohol Induced-Fatty Liver Disease by Ameliorating Oxidative Stress and Inflammation in Mice.

Alcoholic fatty liver disease (AFLD) is a common chronic liver disease and has become a critical global public health problem. Green tea is a popular drink worldwide and contains several bioactive compounds. Different green teas could contain diverse compounds and possess distinct bioactivities. In the present study, the effects of 10 green teas on chronic alcohol induced-fatty liver disease in mice were explored and compared. The results showed that several green teas significantly reduced triacylglycerol levels in serum and liver as well as the aminotransferase activities in mice at a dose of 200 mg/kg, suggesting that they possess hepatoprotective effects. Moreover, several green teas remarkably decreased the expression of cytochrome P450 2E1, the levels of malondialdehyde and 4-hydroxynonenoic acid, and the contents of proinflammatory cytokines, indicating that they could alleviate oxidation damage and inflammation induced by chronic alcohol exposure. In addition, Seven Star Matcha Tea and Selenium-Enriched Matcha Tea could increase glutathione level. Furthermore, the main phytochemical components in green teas were determined and quantified by high-performance liquid chromatography, and the correlation analysis showed that gallic acid, gallocatechin, catechin, chlorogenic acid, and epigallocatechin gallate might at least partially contribute to protective effects on AFLD. In conclusion, Selenium-Enriched Chaoqing Green Tea, Xihu Longjing Tea, Taiping Houkui Tea, and Selenium-Enriched Matcha Tea showed the strongest preventive effects on AFLD. This research also provides the public with new insights about the effects of different green teas on AFLD.

Puerariae Lobatae radix flavonoids and puerarin alleviate alcoholic liver injury in zebrafish by regulating alcohol and lipid metabolism.

Exessive drinking is commonly associated with a wide spectrum of liver injuries. The term alcoholic liver disease (ALD) is generally used to refer to this spectrum of hepatic abnormalities, and the term hepatic steatosis denotes early lesions. Puerariae Lobatae Radix (PLR) is a common traditional Chinese medicine and has been widely used as an efficient treatment for alcohol-induced damage. Flavonoids are the principal components of PLR that could potentially be responsible for the activation of alcohol metabolism and lipid-lowering effects. However, little is known about the mechanisms underlying their activity against alcoholic injury. In this study, PLR flavonoids (PLF) were obtained by microwave extraction. A 2% ethanol solution was used to establish a model of alcoholic fatty liver disease by exposure of zebrafish larvae for 32 h, and then the zebrafish were administered PLF and puerarin. The results showed that PLF and puerarin significantly decreased lipid accumulation and the levels of total cholesterol and triglycerides in zebrafish larvae. Moreover, PLF and puerarin downregulated the expression of genes related to alcohol and lipid metabolism (CYP2y3, CYP3a65, ADH8a, ADH8b, HMGCRB, and FASN), endoplasmic reticulum stress, and DNA damage (CHOP, EDEM1, GADD45αa, and ATF6) and reduced levels of inflammatory factors (IL-1ß, TNF-α) in zebrafish larvae. PLF and puerarin increased the phosphorylation of AMP-activated protein kinase-α (AMPKα) and decreased the total protein level of ACC1. The findings suggested that PLF and puerarin alleviated alcohol-induced hepatic steatosis in zebrafish larvae by regulating alcohol and lipid metabolism, which was closely related to the regulation of the AMPKα-ACC signaling pathway. In conclusion, the study provided a possible therapeutic drug for ALD treatment.

Live Confocal Imaging as a Novel Tool to Assess Liver Quality: Insights From a Murine Model.

BACKGROUND: In an experimental murine liver clamping model, we aimed to investigate the efficacy of real-time confocal microscopy (RCM) in assessing viability of steatotic livers in comparison to standard assessment tools, including histopathological evaluation. METHODS: C57Bl/6 mice were subjected to a methionine-choline-deficient diet causing nonalcoholic fatty liver disease or to Lieber DeCarli diet causing ethanol-induced liver injury. Untreated animals served as controls. Liver biopsies were analyzed following challenge with 45 min of warm ischemia time and either 4 h of reperfusion or 24 h of cold storage. Organ quality assessment was performed at defined time points by RCM, histological staining, measurement of serum alanine aminotransferase activity, and expression analyses of proinflammatory cytokines. Additionally, survival analysis was performed. RESULTS: Cold as well as warm ischemia time resulted in a significant decrease in cell viability when compared with naive livers as well as nonischemic-challenged steatotic livers (P < 0.05) as assessed by RCM. Furthermore, RCM revealed the actual cellular damage at early time points, while established methods including H&E-staining and serum transaminase profile failed. CONCLUSIONS: In a translational attempt, we demonstrate that RCM is a suitable diagnostic tool to obtain information about functional damage of the liver apart from standard approaches.