Pathogenesis Of Fatty Liver Disease Research Articles

Deciphering the impact and mechanism of total flavonoids from Cortex Juglandis Mandshuricae on alcoholic fatty liver employing LC-MS/MS, network pharmacology analysis and in vitro validation

The Cortex Juglandis Mandshuricae (CJM) has the efficacy of penetrating the liver meridian, removing heat and dampness, and alleviating the liver, which corresponds to the pathogenesis of alcoholic fatty liver disease (AFLD) with damp heat accumulation. Modern research has shown that total flavonoids from Cortex Juglandis Mandshuricae (TFC) have hepatoprotective, antioxidant and antitumour pharmacological effects. However, there is no any investigation on the mechanism of TFC improving AFLD. In this work, a valid strategy combining UPLC-Q-Exactive Orbitrap-MS, network pharmacology and in vitro cellular experimental validation is proposed to predict the targets and pathways of total flavonoids from Cortex Juglandis Mandshuricae (TFC) to ameliorate AFLD and to explore its mechanism of action. As a result, 26 flavonoids and 182 targets linked to TFC and AFLD were identified. These compounds realize their critical targets via various signaling pathways and perform multiple biological functions on the basis of the constructed compound-disease target networks. In vitro experiments demonstrated TFC had a protective impact on ethanol-treated L02 cells to a certain extent and could diminished lipid accretion. In addition, RT-qPCR and western blot results illustrated that TFC could regulate the expression of PPARα, CPT-1, SREBP-1c and FAS, and inhibit alcohol-induced lipid accumulation in L02 cells thereby alleviating AFLD. The present study further provides experimental justification for TFC to ameliorate AFLD in practical applications.

Diosgenin ameliorating non-alcoholic fatty liver disease via Nrf2-mediated regulation of oxidative stress and ferroptosis.

This study aimed to investigate the mechanisms through which diosgenin inhibits the pathogenesis of non-alcoholic fatty liver disease, focusing particularly on ferroptosis-related pathways and its reliance on nuclear factor erythroid 2-related factor 2. Using a rat model, we showed diosgenin's efficacy in reducing lipid deposition throughout the body and examined its impact on ferroptosis-related gene expression in vivo. Moreover, in vitro experiments using human hepatocellular liver carcinoma cell line cells were conducted to assess oxidative stress and ferroptosis levels. Diosgenin decreased lipid accumulation and steatosis; lowered serum levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol, glutamic pyruvic transaminase and glutamic oxaloacetic transaminase; reduced interleukin-1β and tumour necrosis factor-α; diosgenin decreased malondialdehyde levels; and increased serum superoxide dismutase levels in a rat model of high-fat diet-induced non-alcoholic fatty liver disease. Diosgenin upregulated the expression of nuclear factor erythroid 2-related factor 2 and its downstream ferroptosis-related genes to inhibit ferroptosis in the livers of rats with non-alcoholic fatty liver disease. Diosgenin decreased reactive oxygen species levels and enhanced the expression of ferroptosis-related genes in human hepatocellular liver carcinoma cells induced by free fatty acids, with its effects being dependent on nuclear factor erythroid 2-related factor 2. This study highlights the potential of diosgenin from Dioscoreaceae plants in mitigating oxidative stress and ferroptosis levels through nuclear factor erythroid 2-related factor 2 regulation, offering novel insights into the treatment of non-alcoholic fatty liver disease and other metabolic disorders through traditional Chinese medicine.

Can Cardiovascular Risk Be Simply Estimated in Nonalcoholic Fatty Liver Disease Patients?

Backgrounds and Aims: In the pathogenesis of nonalcoholic fatty liver disease (NAFLD), inflammation plays a pivotal role. The presence of inflammatory cells is closely linked with epicardial adipose tissue (EAT). A recently identified prognostic indicator for cardiovascular disease (CVD) is the ratio of monocyte count to HDL-cholesterol (MHR). Our primary aim was to investigate the relationship between EAT and markers of inflammation in individuals with NAFLD, and to evaluate its predictability using straightforward diagnostic measures. Material-Method: This retrospective study included two hundred eighteen patients who underwent thoracic computed tomography angiography between 2014 and 2021. The patients were divided into the NAFLD group (HU48 IU) according to the liver attenuation ratio. 136 patients in the NAFLD group and 82 in the non-NAFLD group. Results: The body mass index (BMI), triglyceride levels, notably the EAT volume and MHR in the NAFLD group, exhibited higher values than non-NAFLD group. Among participants in the NAFLD group, a positive correlation was observed between EAT volume and factors such as age, MHR, c-reactive protein, BMI, urea, glucose, and alanine aminotransferase. Through linear regression analysis, it was determined that MHR stood as the sole independent predictor of EAT volume in patients with NAFLD. Conclusion: EAT volume, a risk marker for CVD, can be predicted in NAFLD patients by MHR without radiological methods. Thus, easier and earlier detection of NAFLD patients in the high-risk group for CVD will be possible.

Osteokines in Nonalcoholic Fatty Liver Disease.

To critically summarize evidence on the potential role of osteokines in the pathogenesis and progression of nonalcoholic fatty liver disease (NAFLD). There are emerging data supporting that certain osteokines, which are specific bone-derived proteins, may beneficially or adversely affect hepatic metabolism, and their alterations in the setting of osteoporosis or other bone metabolic diseases may possibly contribute to the development and progression of NAFLD. There is evidence showing a potential bidirectional association between NAFLD and bone metabolism, which may imply the existence of a liver-bone axis. In this regard, osteocalcin, osteoprotegerin, bone morphogenic protein 4 (BMP4) and BMP6 appear to have a positive impact on the liver, thus possibly alleviating NAFLD, whereas osteopontin, receptor activator of nuclear factorkappaΒ ligand (RANKL), sclerostin, periostin, BMP8B, and fibroblast growth factor 23 (FGF23) appear to have a negative impact on the liver, thus possibly exacerbating NAFLD. The potential implication of osteokines in NAFLD warrants further animal and clinical research in the field that may possibly result in novel therapeutic targets for NAFLD in the future.

Polyribonucleotide nucleotidyltransferase 1 participates in metabolic-associated fatty liver disease pathogenesis by affecting lipid metabolism and mitochondrial homeostasis

ObjectiveMetabolic-associated fatty liver disease (MAFLD) represents one of the most prevalent chronic liver conditions worldwide, but its precise pathogenesis remains unclear. This research endeavors to elucidate the involvement and molecular mechanisms of polyribonucleotide nucleotidyltransferase 1 (PNPT1) in the progression of MAFLD. MethodsThe study employed western blot and qRT-PCR to evaluate PNPT1 levels in liver specimens from individuals diagnosed with MAFLD and in mouse models subjected to a high-fat diet. Cellular studies investigated the effects of PNPT1 on lipid metabolism, apoptosis, and mitochondrial stability in hepatocytes. Immunofluorescence was utilized to track the subcellular movement of PNPT1 under high lipid conditions. RNA immunoprecipitation and functional assays were conducted to identify interactions between PNPT1 and Mcl-1 mRNA. The role of PPARα as an upstream transcriptional regulator of PNPT1 was investigated. Recombinant adenoviral vectors were utilized to modulate PNPT1 expression in vivo. ResultsPNPT1 was found to be markedly reduced in liver tissues from MAFLD patients and HFD mice. In vitro, PNPT1 directly regulated hepatic lipid metabolism, apoptosis, and mitochondrial stability. Under conditions of elevated lipids, PNPT1 relocated from mitochondria to cytoplasm, modifying its physiological functions. RNA immunoprecipitation revealed that the KH and S1 domains of PNPT1 bind to and degrade Mcl-1 mRNA, which in turn affects mitochondrial permeability. The transcriptional regulator PPARα was identified as a significant influencer of PNPT1, impacting both its expression and subsequent cellular functions. Alterations in PNPT1 expression were directly correlated with the progression of MAFLD in mice. ConclusionsThe study confirms the pivotal function of PNPT1 in the development of MAFLD through its interactions with Mcl-1 and its regulatory effects on lipid metabolism and mitochondrial stability. These insights highlight the intricate association between PNPT1 and MAFLD, shedding light on its molecular pathways and presenting a potential new therapeutic avenue for MAFLD management.

NLRP3 inflammasome pathway involved in the pathogenesis of metabolic associated fatty liver disease

The prevalence of Metabolic-associated fatty liver disease (MAFLD) has been steadily increasing worldwide, paralleling the global epidemic of obesity and diabetes. It is estimated that approximately one-quarter of the global population is affected by MAFLD. Despite its high prevalence, MAFLD often goes undiagnosed due to the lack of specific symptoms in its early stages. However, as the disease progresses, it can lead to more severe liver-related complications such as fibrosis, cirrhosis, and hepatocellular carcinoma. Therefore, we aimed to investigate the expression levels of the nucleotide-binding oligomerization domain, leucine-rich repeat (LRR)—containing proteins (NLR) family pyrin domain-containing protein 3 [NLRP3] inflammasome pathway components, NLRP3 and interleukin 1β (IL-1β) genes in patients with MAFLD with various degrees of steatosis and fibrosis. Participants were classified into two equal groups; MAFLD group: consisted of 120 patients with different degrees of hepatic fibrosis and steatosis based on fibro scan results. The non-MAFLD group was comprised of 107 participants. Molecular analysis of pyrin domain-containing protein 3 and IL-1β relative gene expressions was performed in the blood of all participants, using Real-time quantitative polymerase chain reaction (RT-qPCR). Patients with post-MAFLD hepatic fibrosis had significantly higher relative gene expression levels of IL-1β and NLRP3; with IL-1β > 1.1 had AUC of 0.919, sensitivity of 88.33, specificity of 96.26, PPV of 96.4, and NPV of 88 and 92.3 accuracy (p value < 0.001). NLRP3 > 1.33 had a sensitivity of 97.5, specificity of 99.07, PPV of 99.2, NPV of 97.2, and 98.3 accuracy with an AUC of 0.991 (p value < 0.001) as predictors of post-MAFLD hepatic fibrosis.. A significant increase in the mean relative gene expression levels of both IL-1β and NLRP3 found in patients with early fibrosis (F0-F1-2); 31.97 ± 11.8 and 6.76 ± 2.18, respectively; compared with patients with advanced hepatic fibrosis stages (F2-F3); 2.62 ± 3.71 and 4.27 ± 2.99 (p < 0.001 each). The present study provides novel evidence for the possible involvement of IL-1β and NLRP3 inflammasome in metabolic-associated fatty liver disease pathogenesis and could be valid markers for the early detection of post-MAFLD hepatic fibrosis.

Core competing endogenous RNA network based on mRNA and non-coding RNA expression profiles in chicken fatty liver.

Fatty liver disease is a common metabolic disease in chickens. This disease can lead to a decrease in egg production and increase the risk of death in chickens. Long non-coding RNAs (lncRNAs) are involved in fatty liver formation by directly targeting genes or regulating gene expression by competitively binding microRNAs. However, a large proportion of competing endogenous RNA (ceRNA) networks in fatty liver diseases are still unclear. The total of 300 Jingxing-Huang chickens were used for fatty liver model construction. Then, differentially expressed (DE) genes (DEGs) identified through whole-transcriptome sequencing from four chickens with fatty liver and four chickens without fatty liver were chosen from the F1 generation. A total of 953 DEGs were identified between the fatty liver group and the control group, including 26 DE micro (mi)RNAs and 56 DE lncRNAs. Differential expression heatmaps and volcano plots were obtained after clustering expression analysis. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that these DEGs were involved in many biological processes and signaling pathways related to fatty acid metabolism and lipid synthesis. Furthermore, cytoscape was used to construct a ceRNA network of the DE miRNAs, DE mRNAs, and DE lncRNAs. Eleven DE lncRNAs, seven DE miRNAs, and 13 DE mRNAs were found to be associated with the pathogenesis of fatty liver disease. An lncRNA-miRNA-mRNA ceRNA network was constructed to elucidate the mechanisms of fatty liver diseases, and the ENSGALT00000079786-miR-140/miR-143/miR-1a/miR-22/miR-375 network was identified. These results provide a valuable resource for further elucidating the posttranscriptional regulatory mechanisms of chicken liver and adipose fat development or deposition.

Biochemical and histological changes in two nonalcoholic fatty liver disease models of different severity

Background. One of the priority areas of modern medicine, which unites the interests of various specialists (therapists, cardiologists, gastroenterologists, endocrinologists), is the study of the pathogenesis and clinical manifestations of nonalcoholic fatty liver disease (NAFLD), which is widespread and of unconditional social significance. The search for adequate experimental models of NAFLD that reflect the severity of liver damage is of paramount importance for studying its etiology and pathogenesis.The aim of the study. To compare biochemical and histological changes in experimental models of NAFLD of varying severity.Materials and methods. Two NAFLD model versions were used: a light one – nonalcoholic steatosis (NAS) and a severe variant – non-alcoholic steatohepatitis (NASH). The following biochemical parameters were measured: enzyme activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (AP), plasma glucose concentration, total protein (TP), total bilirubin (TBil) and its conjugate fraction (CB), plasma concentrations of homocysteine (HC), total cholesterol (TC), triacylglycerides (TG), catalase (Cat), superoxide dismutase (SOD) and malondialdehyde (MDA).Results. When used in a model of steatohepatitis, liver function was impaired to a significantly greater extent than in the model of steatosis; this difference was manifested in a statistically significant increase in ALT, AST, AP, TC, Tbil, MDA (p &lt; 0.001) and a decrease in Cat, SOD (p &lt; 0.05). This is confirmed by the development of more pronounced symptoms of disorders of pigment and lipid metabolism, cytolytic and cholestatic syndromes, significant activation of lipid peroxidation and depression of the antioxidant system when modeling non-alcoholic steatohepatitis. Various degrees of severity of morphological changes in the experimental groups were revealed.Conclusion. The study showed the priority of determining biochemical markers, including the levels of ALT, AST, OBIL, TG, MDA and SOD to optimize laboratory methods for diagnosing the severity of liver dystrophy.The practical originality of the results lies in the optimization of the methodology for laboratory diagnosis of the severity of the pathological process in NAFLD.

Association of Obstructive Sleep Apnea with Nonalcoholic Fatty Liver Disease: Evidence, Mechanism, and Treatment.

Obstructive sleep apnea (OSA), a common sleep-disordered breathing condition, is characterized by intermittent hypoxia (IH) and sleep fragmentation and has been implicated in the pathogenesis and severity of nonalcoholic fatty liver disease (NAFLD). Abnormal molecular changes mediated by IH, such as high expression of hypoxia-inducible factors, are reportedly involved in abnormal pathophysiological states, including insulin resistance, abnormal lipid metabolism, cell death, and inflammation, which mediate the development of NAFLD. However, the relationship between IH and NAFLD remains to be fully elucidated. In this review, we discuss the clinical correlation between OSA and NAFLD, focusing on the molecular mechanisms of IH in NAFLD progression. We meticulously summarize clinical studies evaluating the therapeutic efficacy of continuous positive airway pressure treatment for NAFLD in OSA. Additionally, we compile potential molecular biomarkers for the co-occurrence of OSA and NAFLD. Finally, we discuss the current research progress and challenges in the field of OSA and NAFLD and propose future directions and prospects.

TXNDC5 Plays a Crucial Role in Regulating Endoplasmic Reticulum Activity through Different ER Stress Signaling Pathways in Hepatic Cells.

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is influenced by a number of variables, including endoplasmic reticulum stress (ER). Thioredoxin domain-containing 5 (TXNDC5) is a member of the protein disulfide isomerase family and acts as an endoplasmic reticulum (ER) chaperone. Nevertheless, the function of TXNDC5 in hepatocytes under ER stress remains largely uncharacterized. In order to identify the role of TXNDC5 in hepatic wild-type (WT) and TXNDC5-deficient (KO) AML12 cell lines, tunicamycin, palmitic acid, and thapsigargin were employed as stressors. Cell viability, mRNA, protein levels, and mRNA splicing were then assayed. The protein expression results of prominent ER stress markers indicated that the ERN1 and EIF2AK3 proteins were downregulated, while the HSPA5 protein was upregulated. Furthermore, the ATF6 protein demonstrated no significant alterations in the absence of TXNDC5 at the protein level. The knockout of TXNDC5 has been demonstrated to increase cellular ROS production and its activity is required to maintain normal mitochondrial function during tunicamycin-induced ER stress. Tunicamycin has been observed to disrupt the protein levels of HSPA5, ERN1, and EIF2AK3 in TXNDC5-deficient cells. However, palmitic acid has been observed to disrupt the protein levels of ATF6, HSPA5, and EIF2AK3. In conclusion, TXNDC5 can selectively activate distinct ER stress pathways via HSPA5, contingent on the origin of ER stress. Conversely, the absence of TXNDC5 can disrupt the EIF2AK3 cascade.

Liver epigenomic signature associated with chronic oxidative stress in a mouse model of glutathione deficiency

Oxidative stress is intimately involved in the pathogenesis of fatty liver disease (FLD). A major factor contributing to oxidative stress is the depletion of the ubiquitous antioxidant glutathione (GSH). Unexpectedly, chronic GSH deficiency renders glutamate-cysteine ligase modifier subunit (Gclm)-null mice protected from fatty liver injuries. Epigenetic regulation serves as an important cellular mechanism in modulating gene expression and disease outcome in FLD, although it is not well understood how systemic redox imbalance modifies the liver epigenome. In the current study, utilizing the Gclm-null mouse model, we aimed to elucidate redox-associated epigenomic changes and their implications in liver stress response. We performed high-throughput array-based DNA methylation profiling (MeDIP array) in 22,327 gene promoter regions (from −1300 bp to +500 bp of the Transcription Start Sites) in the liver and peripheral blood cells. Results from the MeDIP array demonstrate that, although global methylation enrichment in gene promoters did not change, low GSH resulted in prevalent demethylation at the individual promoter level. Such an effect likely attributed to a declined availability of the methyl donor S-adenosyl methionine (SAM) in Gclm-null liver. Functional enrichment analysis of liver target genes is suggestive of a potential role of epigenetic mechanisms in promoting cellular survival and lipid homeostasis in Gclm-null liver. In comparison with the liver tissue, MeDIP array in peripheral blood cells revealed a panel of 19 gene promoters that are candidate circulating biomarkers for hepatic epigenomic changes associated with chronic GSH deficiency. Collectively, our results provided new insights into the in vivo interplay between liver redox state and DNA methylation status. The current study laid the groundwork for future epigenetic/epigenomic investigations in experimental settings or human populations under conditions of liver oxidative stress induced by environmental or dietary challenges.

Impact of lifestyle interventions on pathogenesis of nonalcoholic fatty liver disease

Impact of lifestyle interventions on pathogenesis of nonalcoholic fatty liver disease

Asprosin aggravates nonalcoholic fatty liver disease via inflammation and lipid metabolic disturbance mediated by reactive oxygen species.

Asprosin (ASP) is a newly-identified adipokine and plays important roles in energy metabolism homeostasis. However, there is no report on whether and how ASP is involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Therefore, in the study, we investigated the protective effects of ASP-deficiency on the liver in the NAFLD model mice and the detrimental effects of ASP treatment on the human normal hepatocytes (LO2 cell line). More important, we explored the underlying mechanism from the perspective of lipid metabolism and inflammation. In the in vivo experiments, our data showed that the ASP-deficiency significantly alleviated the high-fat diet-induced inflammation and NAFLD, inhibited the hepatic fat deposition and downregulated the expressions of fat acid synthase (FASN), peroxisome proliferator-activated receptor γ (PPARγ) and forkhead box protein O1 (FOXO1); moreover, the ASP-deficiency attenuated the inflammatory state and inhibited the activation of the IKK/NF-κBp65 inflammation pathway. In the in vitro experiments, our results revealed that ASP treatment caused and even exacerbated the injury of LO2 cells induced by FFA; In contrast, the ASP treatment upregulated the expressions of PPARγ, FOXO1, FASN, ACC and acyl-CoA oxidase 1 (ACOX1) and elevated the reactive oxygen species (ROS) levels. Accordingly, these results demonstrate that ASP causes NAFLD through disrupting lipid metabolism and promoting the inflammation mediated by ROS.

Genetic predisposition to metabolic dysfunction-associated fatty liver disease

The literature review highlights the issue of genetic risk factors associated with the development of metabolic dysfunction-associated fatty liver disease. Human genetic examinations revealed 132 genes among which 32 loci are strongly associated with the pathogenesis of metabolic dysfunction-associated fatty liver disease. It has been found that the risk of developing metabolic dysfunction-associated fatty liver disease is carried by single-nucleotide variants of various genes whose products are involved in lipid and carbohydrate metabolism, maintenance of the redox state, the development of inflammation and fibrosis of liver tissue, which are components of metabolic dysfunction-associated fatty liver disease reactome. The authors presented a detailed list of genetic factors singling out those that influence the risk of metabolic dysfunction-associated fatty liver disease and directly metabolic dysfunction-associated steatohepatitis and liver fibrosis. Also, they emphasized that it is the single-nucleotide variants of the genes of protein 3 containing a patatin-like phospholipase domain, transmembrane 6 superfamily member 2, and 17b-hydroxysteroid dehydrogenase type 13 that are characte­rized by the highest degree of association with metabolic dysfunction-associated fatty liver disease (odds ratio &gt; 1.6) compared to single-nucleotide variants of other genes identified by gene association studies. The combination of several polymorphisms increases the risk of development and severity of metabolic dysfunction-associated fatty liver disease. The additive steatogenic effect of protein 3 single-nucleotide gene variants containing a patatin-like phospholipase domain and transmembrane 6 superfamily member 2 is probably due to an increased expression of genes involved in de novo lipogenesis. The authors emphasize the need for genetic risk assessment of metabolic dysfunction-associated fatty liver disease, which should include molecular genetic testing at an early stage of examination.

Oleuropein, a Component of Extra Virgin Olive Oil, Improves Liver Steatosis and Lobular Inflammation by Lipopolysaccharides-TLR4 Axis Downregulation.

Gut-dysbiosis-induced lipopolysaccharides (LPS) translocation into systemic circulation has been suggested to be implicated in nonalcoholic fatty liver disease (NAFLD) pathogenesis. This study aimed to assess if oleuropein (OLE), a component of extra virgin olive oil, lowers high-fat-diet (HFD)-induced endotoxemia and, eventually, liver steatosis. An immunohistochemistry analysis of the intestine and liver was performed in (i) control mice (CTR; n = 15), (ii) high-fat-diet fed (HFD) mice (HFD; n = 16), and (iii) HFD mice treated with 6 µg/day of OLE for 30 days (HFD + OLE, n = 13). The HFD mice developed significant liver steatosis compared to the controls, an effect that was significantly reduced in the HFD + OLE-treated mice. The amount of hepatocyte LPS localization and the number of TLR4+ macrophages were higher in the HFD mice in the than controls and were lowered in the HFD + OLE-treated mice. The number of CD42b+ platelets was increased in the liver sinusoids of the HFD mice compared to the controls and decreased in the HFD + OLE-treated mice. Compared to the controls, the HFD-treated mice showed a high percentage of intestine PAS+ goblet cells, an increased length of intestinal crypts, LPS localization and TLR4+ expression, and occludin downregulation, an effect counteracted in the HFD + OLE-treated mice. The HFD-fed animals displayed increased systemic levels of LPS and zonulin, but they were reduced in the HFD + OLE-treated animals. It can be seen that OLE administration improves liver steatosis and inflammation in association with decreased LPS translocation into the systemic circulation, hepatocyte localization of LPS and TLR4 downregulation in HFD-induced mouse model of NAFLD.

Gut Microbiota Profile Changes in Patients with Inflammatory Bowel Disease and Non-Alcoholic Fatty Liver Disease: A Metagenomic Study.

Gut microbiota imbalances have a significant role in the pathogenesis of Inflammatory Bowel Disease (IBD) and Non-Alcoholic Fatty Liver Disease (NAFLD). Herein, we compared gut microbial composition in patients diagnosed with either IBD or NAFLD or a combination of both. Seventy-four participants were stratified into four groups: IBD-NAFLD, IBD-only, NAFLD-only patients, and healthy controls (CTRLs). The 16S rRNA was sequenced by Next-Generation Sequencing. Bioinformatics and statistical analysis were performed. Bacterial α-diversity showed a significant lower value when the IBD-only group was compared to the other groups and particularly against the IBD-NAFLD group. β-diversity also showed a significant difference among groups. The higher Bacteroidetes/Firmicutes ratio was found only when comparing IBD groups and CTRLs. Comparing the IBD-only group with the IBD-NAFLD group, a decrease in differential abundance of Subdoligranulum, Parabacteroides, and Fusicatenibacter was found. Comparing the NAFLD-only with the IBD-NAFLD groups, there was a higher abundance of Alistipes, Odoribacter, Sutterella, and Lachnospira. An inverse relationship in the comparison between the IBD-only group and the other groups was shown. For the first time, the singularity of the gut microbial composition in IBD and NAFLD patients has been shown, implying a potential microbial signature mainly influenced by gut inflammation.

Unveiling the role of disulfidptosis-related genes in the pathogenesis of non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) presents as a common liver disease characterized by an indistinct pathogenesis. Disulfidptosis is a recently identified mode of cell death. This study aimed to investigate the potential role of disulfidptosis-related genes (DRGs) in the pathogenesis of NAFLD. Gene expression profiles were obtained from the bulk RNA dataset GSE126848 and the single-cell RNA dataset GSE136103, both associated with NAFLD. Our study assessed the expression of DRGs in NAFLD and normal tissues. Weighted gene co-expression network analysis (WGCNA) and differential expression analysis were employed to identify the key NAFLD-specific differentially expressed DRGs (DE-DRGs). To explore the biological functions and immune regulatory roles of these key DE-DRGs, we conducted immune infiltration analysis, functional enrichment analysis, consensus clustering analysis, and single-cell differential state analysis. Finally, we validated the expression and biological functions of DRGs in NAFLD patients using histology and RNA-sequencing transcriptomic assays with human liver tissue samples. Through the intersection of WGCNA, differentially expressed genes, and DRGs, two key DE-DRGs (DSTN and MYL6) were identified. Immune infiltration analysis indicated a higher proportion of macrophages, T cells, and resting dendritic cells in NAFLD compared to control liver samples. Based on the key DE-DRGs, Two disulfidptosis clusters were defined in GSE126848. Cluster 1, with higher expression of the key DE-DRGs, exhibited increased immune infiltration abundance and was closely associated with oxidative stress and immune regulation compared to cluster 2. High-resolution analysis of mononuclear phagocytes highlighted the potential role of MYL6 in intrahepatic M1 phenotype Kupffer cells in NAFLD patients. Our transcriptome data revealed that the expression levels of the majority of DRGs were significantly increased in NAFLD patients. NAFLD patients exhibit elevated MYL6 correlating with inflammation, oxidative stress, and disease severity, offering promising diagnostic specificity. This comprehensive study provides evidence for the association between NAFLD and disulfidptosis, identifying potential target genes and pathways in NAFLD. The identification of MYL6 as a possible treatment target for NAFLD provided a novel understanding of the disease's development.

Hepatokine ITIH3 Protects Against Hepatic Steatosis by Downregulating Mitochondrial Bioenergetics and De Novo Lipogenesis

Accumulating evidence suggest that mitochondrial functions are altered and contribute to the pathogenesis of non-alcoholic fatty liver disease (NAFLD). As a result, research is being conducted to discover targets that alter mitochondrial functions to ameliorate NAFLD, and its progression towards non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). Recent studies demonstrate that liver secretory proteins regulate normal development, obesity, simple steatosis to NASH progression. Inter-α-trypsin inhibitors (ITI) are one such proteins secreted by liver, altered in NAFLD, but their functional importance in mitochondrial metabolism is poorly understood. Here, we have identified that ITIH3 is a potential candidate gene that protects against NAFLD by targeting mitochondrial metabolism. We used an integrative multiomics approach using transcriptomic data from approximately 100 different mouse strains called hybrid mouse diversity panel (HMDP) and a cohort of bariatric surgery patients and identified Itih3/ITIH3 expression to be inversely associated with NAFLD/NASH progression and hepatic TG accumulation. Our network enrichment analyses revealed NAFLD-related pathways such as mitochondria, TCA cycle, fatty acid metabolism, cholesterol metabolism, coagulation and fibrinolysis. Next, disease enrichments by ToppGene revealed metabolic syndrome-related disease traits including dyslipidemia, steatosis, NASH and fibrosis. Our in vitro and in vivo studies using loss and gain of function mouse and cell culture models demonstrated that hepatic ITIH3 reduced liver triglyceride accumulation and de novo lipogenesis (DNL). Remarkably, hepatic ITIH3 also lowered mitochondrial respiration and lipid droplet accumulation. This was accompanied by increased STAT1 signaling and Stat3 expression, both of which are known to protect against NAFLD/NASH. Together, we conclude that ITIH3 plays a unique role in regulating the hepatic lipid profile, DNL, and mitochondrial metabolism, all of which have implications for NAFLD treatment. Our findings indicate hepatokine ITIH3 as a potential biomarker and/or treatment for NAFLD. R00DK120875. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Mitochondrial dysfunction of the inner membrane of hepatocytes in the development of glutamate-induced steatohepatosis and its correction

Elucidation of the mechanisms of the development of liver steatosis, which are at the heart of the pathogenesis of nonalcoholic fatty liver disease (NAFLD), will allow the introduction of new effective treatment methods into medical practice, as well as the development of new measures for the correction of this disease and accompanying pathologies. The purpose of the research is to establish the enzymatic activity of the complexes of the electron transport chain of the mitochondrial membrane of rat hepatocytes and to evaluate the corrective effect of the multiprobiotic “Symbiter acidophilic” concentrated or nanocrystalline cerium dioxide on the formation of steatohepatosis induced by neonatal sodium glutamate administration. The experiments were carried out on 50 white non-linear male rats; the direction included the study of the mechanisms of the development of steatohepatosis in 4-month-old rats, which were administered monosodium glutamate in the neonatal period, and the study of the functional state of the liver in rats after the neonatal administration of monosodium glutamate against the background of periodic administration of a multiprobiotic or nanocrystalline dioxide cerium. It was established that neonatal administration of monosodium glutamate causes metabolic changes in 4-month-old rats, manifested in the disproportionate accumulation of fat with the development of visceral obesity without hyperphagia, dyslipidemia, and steatohepatosis. In 4-month-old rats, after neonatal administration of sodium glutamate, the development of steatohepatosis was accompanied by mitochondrial dysfunction, which was manifested by changes in the lipid composition of the inner membrane of hepatocyte mitochondria with an increase in oxidized products and a change in the enzymatic activity of all complexes of the respiratory chain. In rats injected with monosodium glutamate in the neonatal period, periodic use of the multiprobiotic “Symbiter acidophilic” concentrated or nanocrystalline cerium dioxide significantly restored the functional state of the liver, reduced the manifestations of oxidative stress and prevented the development of steatohepatosis, which indicates the antioxidant effect of these drugs and the possibility of their use for prevention of steatohepatosis.

Competitive adsorption of microRNA-532-3p by circular RNA SOD2 activates Thioredoxin Interacting Protein/NLR family pyrin domain containing 3 pathway and promotes pyroptosis of non-alcoholic fatty hepatocytes

ObjectiveThere is a growing body of evidence indicating that pyroptosis, a programmed cell death mechanism, plays a crucial role in the exacerbation of inflammation and fibrosis in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Circular RNAs (circRNAs), functioning as vital regulators within NAFLD, have been shown to mediate the process of cell pyroptosis. This study aims to elucidate the roles and mechanisms of circRNAs in NAFLD.MethodsUtilizing a high-fat diet (HFD)-induced rat model for in vivo experimentation and hepatocytes treated with palmitic acid (PA) for in vitro models, we identified circular RNA SOD2 (circSOD2) as our circRNA of interest through analysis with the circMine database. The expression levels of associated genes and pyroptosis-related proteins were determined using quantitative real-time polymerase chain reaction and Western blotting, alongside immunohistochemistry. Serum liver function markers, cellular inflammatory cytokines, malondialdehyde, lactate dehydrogenase levels, and mitochondrial membrane potential, were assessed using enzyme-linked immunosorbent assay, standard assay kits, or JC-1 staining. Flow cytometry was employed to detect pyroptotic cells, and lipid deposition in liver tissues was observed via Oil Red O staining. The interactions between miR-532-3p/circSOD2 and miR-532-3p/Thioredoxin Interacting Protein (TXNIP) were validated through dual-luciferase reporter assays and RNA immunoprecipitation experiments.ResultsOur findings demonstrate that, in both in vivo and in vitro NAFLD models, there was an upregulation of circSOD2 and TXNIP, alongside a downregulation of miR-532-3p. Mechanistically, miR-532-3p directly bound to the 3'-UTR of TXNIP, thereby mediating inflammation and cell pyroptosis through targeting the TXNIP/NLR family pyrin domain containing 3 (NLRP3) inflammasome signaling pathway. circSOD2 directly interacted with miR-532-3p, relieving the suppression on the TXNIP/NLRP3 signaling pathway. Functionally, the knockdown of circSOD2 or TXNIP improved hepatocyte pyroptosis; the deletion of miR-532-3p reversed the effects of circSOD2 knockdown, and the deletion of TXNIP reversed the effects of circSOD2 overexpression. Furthermore, the knockdown of circSOD2 significantly mitigated the progression of NAFLD in vivo.ConclusioncircSOD2 competitively sponges miR-532-3p to activate the TXNIP/NLRP3 inflammasome signaling pathway, promoting pyroptosis in NAFLD.