Severity Of Nonalcoholic Steatohepatitis Research Articles

Single and Mixed Strains of Probiotics Reduced Hepatic Fat Accumulation and Inflammation and Altered Gut Microbiome in a Nonalcoholic Steatohepatitis Rat Model.

As gut dysbiosis has been implicated in the pathogenesis of nonalcoholic steatohepatitis (NASH), probiotic supplementation might be a potential treatment for this condition. The aim of this study was to evaluate the effects of single- and mixed-strain probiotics on the severity of NASH induced by a high-fat, high-fructose (HFHF) diet and their mechanisms of action. Male Sprague-Dawley rats were divided into four groups (n = 7 per group): control group, NASH group, NASH + single-strain group, and NASH + mixed-strain group. In the single-strain and mixed-strain groups, rats received Lactobacillus plantarum B7 and Lactobacillus rhamnosus L34 + Lactobacillus paracasei B13 by oral gavage once daily, respectively. The duration of the study was 6 weeks. Liver tissue was used for histopathology, hepatic fat content was assessed by Oil Red O staining and hepatic free fatty acid (FFA), and hepatic TLR4 and CD14 expression were assessed by immunohistochemistry. Fresh feces was collected for gut microbiota analysis. Liver histology revealed a higher degree of fat accumulation, hepatocyte ballooning, and lobular inflammation in the NASH group, which improved in probiotics-treated groups. The amounts of hepatic fat droplets and hepatic FFA levels were more pronounced in the NASH group than in the control and treatment groups. Serum TNF- α levels were significantly higher in the NASH group than in control and probiotic groups. The expression of CD14 and TLR4 increased in the NASH group as compared with the control and probiotics-treated groups. Alpha diversity was reduced in the NASH group, but increased in both treatment groups. The relative abundance of Lactobacillus significantly decreased in the NASH group, but increased in both treatment groups. The relative abundance of Akkermansia significantly increased in the NASH group, but decreased in both treatment groups. In conclusion, both single-strain and mixed-strain probiotics could improve NASH histology by suppressing inflammatory responses in the liver, with this improvement potentially being associated with changes in the gut microbiota.

Increased phosphatidylcholine and its hydroperoxides in serum low-density lipoproteins from patients with non-alcoholic steatohepatitis.

Non-alcoholic fatty liver disease is classified into simple steatosis (SS) and non-alcoholic steatohepatitis (NASH) according to histological findings from liver biopsies. Phosphatidylcholine (PC), the main component of phospholipids in serum lipoproteins, is easily oxidized to phosphatidylcholine hydroperoxide (PC-OOH). Although a lipid composition in the low-density lipoproteins (LDL) from patients with NASH could be abnormal, it remains unclear. Here, to better understand the characteristics of lipids in the LDL from NASH and SS, we compared the composition of PC and PC-OOH species in LDL particles (LDL-PC, LDL-PCOOH) from these patients, then clarified the association between these lipids and NASH severity. The serum samples from patients with NASH (female, n = 9) and SS (female, n = 4; male, n = 2) were used for isolation of LDL. Total lipids were extracted from isolated LDL, and the species of PC and PC-OOH were measured using liquid chromatography-mass spectrometry/mass spectrometry. The sum of LDL-PC and the sum of LDL-PCOOH were significantly higher in NASH than in SS. Several LDL-PC (PC 32:0, 32:1, 32:2, 34:3, 36:2, sum of PC with saturated fatty acyl chains and sum of LDL-PC with polyunsaturated fatty acyl chains) and several LDL-PCOOH (34:2, 36:2, 36:3 and total) were increased significantly with increasing fibrosis score. In particular, a series of LDL-PCOOH were more reflective of the severity of fibrosis score. LDL-PC and LDL-PCOOH species were strongly correlated with the fibrosis score in NASH, which suggests that abnormal LDL is involved in the development of liver fibrosis.

Influence of nonalcoholic fatty liver disease severity on carotid adventitial vasa vasorum.

Nonalcoholic fatty liver disease (NAFLD) affects a quarter of the world's population and encompasses a spectrum of liver conditions, from non-alcoholic steatohepatitis (NASH) to inflammation and fibrosis. In addition, NAFLD also links to extrahepatic conditions like diabetes or obesity. However, it remains unclear if NAFLD independently correlates with the onset and progression of atherosclerosis. This cross-sectional study aimed to explore the relationship between NAFLD severity, assessed via liver biopsy, and early atherosclerosis using adventitial vasa vasorum (VV) density. It included 44 patients with obesity (33 with steatosis, 11 with NASH) undergoing bariatric surgery. Results revealed no significant differences in adventitial VV density between steatosis and NASH groups, neither in the mean values [0.759 ± 0.104 vs. 0.780 ± 0.043, P=0.702] nor left-right sides. Similarly, carotid intima-media thickness (cIMT) did not vary between these groups. Additionally, no linear correlation existed between VV density and cIMT. Only gender showed an association with VV density. These findings suggest that NASH severity doesn't independently drive early atherosclerosis or affects cIMT. Gender might play a role in early atherosclerotic disease in NAFLD, impacting VV density and cIMT. This highlights the need to consider other risk factors when evaluating cardiovascular risk in NAFLD patients.

Identification of key genes and functional enrichment analysis of liver fibrosis in nonalcoholic fatty liver disease through weighted gene co-expression network analysis.

Nonalcoholic fatty liver disease (NAFLD) is a common type of chronic liver disease, with severity levels ranging from nonalcoholic fatty liver to nonalcoholic steatohepatitis (NASH). The extent of liver fibrosis indicates the severity of NASH and the risk of liver cancer. However, the mechanism underlying NASH development, which is important for early screening and intervention, remains unclear. Weighted gene co-expression network analysis (WGCNA) is a useful method for identifying hub genes and screening specific targets for diseases. In this study, we utilized an mRNA dataset of the liver tissues of patients with NASH and conducted WGCNA for various stages of liver fibrosis. Subsequently, we employed two additional mRNA datasets for validation purposes. Gene set enrichment analysis (GSEA) was conducted to analyze gene function enrichment. Through WGCNA and subsequent analyses, complemented by validation using two additional datasets, we identified five genes (BICC1, C7, EFEMP1, LUM, and STMN2) as hub genes. GSEA analysis indicated that gene sets associated with liver metabolism and cholesterol homeostasis were uniformly downregulated. BICC1, C7, EFEMP1, LUM, and STMN2 were identified as hub genes of NASH, and were all related to liver metabolism, NAFLD, NASH, and related diseases. These hub genes might serve as potential targets for the early screening and treatment of NASH.

Identification of Predictors of Non-alcoholic Steatohepatitis and Its Severity in Individuals Undergoing Bariatric Surgery.

As obesity reached epidemic proportions, non-alcoholic fatty liver disease (NAFLD) also had a worrisome parallel increase. The non-invasive differentiation of non-alcoholic steatohepatitis (NASH) from uncomplicated NAFLD remains an important challenge in current clinical practice. To identify predictors of the occurrence and severity of NAFLD and NASH. This is an analytical cross-sectional study which included individuals undergoing bariatric surgery. Participants were histologically classified according to the presence NASH and severity of NAFLD. Demographic, clinical, anthropometric, and biochemical aspects were analyzed and compared. Out of 171 individuals, 87.7% were female and the mean age was 38.4±9.3 years. The average BMI was 38±3.0 kg/m2. NAFLD was histologically confirmed in 74.9%; the commonest histopathological abnormalities were macrovesicular steatosis (74.9%) and ballooning (40.4%). Simple steatosis occurred in 30.4%, 44.4% presented with NASH, and 31% had severe NAFLD. NASH associated with higher levels of ALT (0.03), ALP (0.02), and glucose (0.02). Cutoff values were, respectively, 23 U/L, 67 U/L, and 81 mg/dL. Their concomitant use provided an 83.1% specificity for NASH. Severe NAFLD associated with diabetes (p=0.02), higher BMI (p=0.01), AST (p=0.04), ALT (p<0.01), ALP (p=0.01), glucose (p=0.02), and ferritin (p<0.01). BMI over 39.3 kg/m2 and ferritin over 178 ng/mL concomitantly provided a 70.5% accuracy for severe NAFLD. NASH and severe NAFLD associated with higher levels of ALT, ALP, and glucose. Severe NAFLD associated with higher BMI and higher ferritin levels in this group. The concomitant evaluation of these laboratory tests could help ruling out NASH and safely screening severe NAFLD.

Time course of western diet (WD) induced nonalcoholic steatohepatitis (NASH) in female and male Ldlr-/- mice.

Nonalcoholic fatty liver disease (NAFLD) is a global health problem. Identification of factors contributing to the onset and progression of NAFLD have the potential to direct novel strategies to combat NAFLD. We examined the time course of western diet (WD)-induced NAFLD and its progression to nonalcoholic steatohepatitis (NASH) in age-matched female and male Ldlr-/- mice, with time-points at 1, 4, 8, 20 and 40 weeks on the WD. Controls included Ldlr-/- mice maintained on a purified low-fat diet (LFD) for 1 and 40 weeks. The approach included quantitation of anthropometric, plasma and liver markers of disease, plus hepatic histology, lipids, oxylipins, gene expression and selected metabolites. One week of feeding the WD caused a significant reduction in hepatic essential fatty acids (EFAs: 18:2, ω6, 18:3, ω3) which preceded the decline in many C20-22 ω3 and ω6 polyunsaturated fatty acids (PUFA) and PUFA-derived oxylipins after 4 weeks on the WD. In addition, expression of hepatic inflammation markers (CD40, CD44, Mcp1, Nlrp3, TLR2, TLR4, Trem2) increased significantly in both female & male mice after one week on the WD. These markers continued to increase over the 40-week WD feeding study. WD effects on hepatic EFA and inflammation preceded all significant WD-induced changes in body weight, insulin resistance (HOMA-IR), oxidative stress status (GSH/GSSG ratio) and histological and gene expression markers of macrosteatosis, extracellular matrix remodeling and fibrosis. Our findings establish that feeding Ldlr-/- mice the WD rapidly lowered hepatic EFAs and induced key inflammatory markers linked to NASH. Since EFAs have an established role in inflammation and hepatic inflammation plays a major role in NASH, we suggest that early clinical assessment of EFA status and correcting EFA deficiencies may be useful in reducing NASH severity.

Risk factors for fibrosis progression in non-alcoholic steatohepatitis: Analysis of the European cohort in the real-world GAIN study

ObjectiveTo better understand drivers of disease progression in non-alcoholic steatohepatitis (NASH), we assessed clinical and sociodemographic markers of fibrosis progression in adults with NASH. Patients and methodsPhysician-reported patient demographics and clinical characteristics were utilised from the real-world Global Assessment of the Impact of NASH (GAIN) study. Factors associated with likelihood of fibrosis progression since NASH diagnosis were identified using a logistic regression model. ResultsOverall, 2349 patients in Europe from the GAIN study were included; mean age was 54.6 years and 41% were women. Significant covariates included age, years since diagnosis, employment status, fibrosis stage at diagnosis, type 2 diabetes mellitus, hypertension, liver transplant and liver biopsy at diagnosis. Risk of progression was 1.16 (95% confidence interval 1.12–1.20; p<0.001) times higher for each additional year since NASH diagnosis and 5.43 (2.68–11.37; p<0.001) times higher when physicians proposed a liver transplant at diagnosis. Compared with full-time employed patients, risk of progression was 1.77 (1.19–2.60; p=0.004) times higher for unemployed patients and 3.16 (1.30–7.63; p=0.010) times higher for those unable to work due to NASH. ConclusionsDisease duration, NASH severity and presence of other metabolic comorbidities could help to assess risk of progression in patients with NASH.

Antimullerian Hormone, a Marker of Ovarian Reserve, Is Protective Against Presence and Severity of NASH in Premenopausal Women

Antimüllerian hormone (AMH) is a marker of ovarian reserve with emerging data linking lower levels to some metabolic and inflammatory diseases in women. Whether AMH levels influence nonalcoholic fatty liver disease (NAFLD) is unknown. Leveraging the NASH Clinical Research Network we determined the association of AMH levels within 6 months of liver biopsy with presence and severity of histologic measures of NAFLD in premenopausal women. Outcomes included presence of nonalcoholic steatohepatitis (NASH), presence and severity of fibrosis, and NAFLD Activity Score and its components. Logistic and ordinal logistic regression models were adjusted for age, race/ethnicity, homeostatic model assessment for insulin resistance, body mass index, dyslipidemia, polycystic ovary syndrome, estrogen-progestin use, and menstrual cyclicity. Median cohort age was 35 years; 73% were white and 24% Hispanic. Thirty-three percent had diabetes, 81% had obesity, and 95% had dyslipidemia. On biopsy 71% had NASH, 68% had any fibrosis, and 15% had advanced fibrosis. On adjusted analysis (n= 205), higher AMH quartiles were inversely associated with NAFLD histology including prevalent NASH (adjusted odds ratio [AOR], 0.64; 95% confidence interval [CI], 0.41-1.00), NAFLD Activity Score ≥5 (AOR, 0.52; 95% CI, 0.35-0.77), Mallory hyaline (AOR, 0.54; 95% CI, 0.35-0.82), and higher fibrosis stage (AOR, 0.70; 95% CI, 0.51-0.98). The protective effects of AMH were more pronounced among women without polycystic ovary syndrome (n= 164), including lower odds of NASH (AOR, 0.53; 95% CI, 0.32-0.90) and any NASH fibrosis (AOR, 0.54; 95% CI, 0.32-0.93). AMH may reflect a unique biomarker of NASH in premenopausal women and findings suggest a novel link between reproductive aging and histologic severity of NAFLD in women.

Host ALDH2 deficiency aggravates nonalcoholic steatohepatitis through gut-liver axis

Nonalcoholic steatohepatitis (NASH) is the major cause of liver dysfunction. Animal and population studies have shown that mitochondrial aldehyde dehydrogenase (ALDH2) is implicated in fatty liver disease. However, the role of ALDH2 in NASH and the underlying mechanisms remains unclear. To address this issue, ALDH2 knockout (ALDH2−/−) mice and wild-type littermate mice were fed a methionine-and choline-deficient (MCD) diet to induce a NASH model. Fecal, serum, and liver samples were collected and analyzed to investigate the impact of the gut microbiota and bile acids on this process. We found that MCD-fed ALDH2−/− mice exhibited increased serum pro-inflammation cytokines, hepatic inflammation and fat accumulation than their wild-type littermates. MCD-fed ALDH2−/− mice exhibited worsened MCD-induced intestinal inflammation and barrier damage, and gut microbiota disorder. Furthermore, mice receiving microbiota from MCD-fed ALDH2−/− mice had increased severity of NASH compared to those receiving microbiota from MCD-fed wild-type mice. Notably, the intestinal Lactobacillus was significantly reduced in MCD-fed ALDH2−/− mice, and gavage with Lactobacillus cocktail significantly improved MCD-induced NASH. Finally, we found that ALDH2-/- mice had reduced levels of bile salt hydrolase and specific bile acids, especially lithocholic acid (LCA), accompanied by downregulated expression of the intestinal FXR-FGF15 pathway. Supplementation of LCA in ALDH2−/− mice upregulated intestinal FXR-FGF15 pathway and alleviated NASH. In summary, ALDH2 plays a critical role in the development of NASH through modulation of gut microbiota and bile acid. The findings suggest that supplementing with Lactobacillus or LCA could be a promising therapeutic approach for treating NASH exacerbated by ALDH2 deficiency.

Selective autophagy associated with iron overload aggravates non-alcoholic steatohepatitis via ferroptosis.

Non-alcoholic steatohepatitis (NASH) is a progressive form of non-alcoholic fatty liver disease (NAFLD) that causes cirrhosis and hepatocellular carcinoma. Iron is an essential trace element in the body; however, excess iron can cause tissue damage and dysfunction. Iron overload is often observed in patients with NASH, and the amount of iron accumulated in the liver positively correlates with the histological severity of NASH. Ferroptosis, a novel form of iron-dependent cell death, is caused by the accumulation of lipid peroxidation and oxidative stress and is related to NASH. In addition, ferroptosis is closely related to autophagy, an intracellular self-degradation process. Although autophagy has many beneficial effects, it may also be harmful to the organism, for example, inducing ferroptosis. It is unclear whether iron overload aggravates NASH via autophagy. The aim of this research is to determine the mechanism by which iron overload induces ferroptosis via autophagy and aggravates NASH. Stroke-prone spontaneously hypertensive rats (SHRSP5/Dmcr) were divided into two groups and fed a high-fat and high-cholesterol (HFC) diet for eight weeks. Iron dextran was administered to the Fe group in addition to the HFC diet. Blood analysis, histological staining, calcineurin activity assay, quantitative reverse transcription polymerase chain reaction (RT-PCR), immunofluorescence staining, and electron microscopy were performed. The results showed that iron overload promoted autophagy via nuclear translocation of transcription factor EB (TFEB) and induced ferritinophagy, which is the autophagic degradation of ferritin. In addition, the HFC diet induced lipophagy, the autophagic degradation of lipid droplets. The Fe group also exhibited promoted ferroptosis and aggravated hepatic inflammation and fibrosis. In conclusion, iron overload accelerates ferritinophagy and lipophagy, aggravating NASH pathology via ferroptosis. These findings indicate the therapeutic potential of inhibiting autophagy and ferroptosis for treating NASH.

1348-P: Glycemic Control Is Associated with the Histological Severity of Nonalcoholic Fatty Liver Disease

Background: Diabetes mellitus (DM) is a major risk for progression of nonalcoholic steatohepatitis (NASH) from nonalcoholic fatty liver (NAFL). Although DM influences on the pathophysiology of NASH, the impact of glycemic control status on the histological severity of NASH is unclear. Methods: We conducted an observational study of 331 patients (140 men and 191 women) diagnosed with nonalcoholic fatty liver disease (NAFLD) by liver biopsy. Impact of glycemic control status on histological severity of NAFLD was evaluated by comparison of the four divided groups, based on the hemoglobin A1c (HbA1c) levels: HbA1c ≤5.4%; 5.5-6.4%; 6.5-7.4%; and ≥7.5%, at the time of liver biopsy. The histological severity of NAFLD was determined by fibrosis staging; stage 0-4, and NAS score; 0-8 points. The advanced liver fibrosis and the high NAS score were defined as stage 3-4 and 5-8 points, respectively. Results: Higher HbA1c groups (5.5-6.4%; 6.5-7.4%; and ≥7.5%) were associated with advanced fibrosis compared to the lowest HbA1c group. In the multivariate analysis, the HbA1c 6.5-7.4% group was significantly associated with advanced fibrosis compared to the lowest HbA1c group after adjusting for age, sex, hemoglobin, alanine aminotransferase, and creatinine levels. When further controlling for body mass index, as well as uric acid, total cholesterol, and triglyceride levels, HbA1c 5.5-6.4%, 6.5-7.4%, ≥7.5% groups were significantly associated with advanced fibrosis compared to the lowest HbA1c group. These HbA1c groups (5.5-6.4%; 6.5-7.4%; and ≥7.5%) were also associated with higher NAFLD activity scores, these associations remained significant in the multivariate analysis. Conclusions: The glycemic control status is strongly associated with the histological severity of NAFLD, even with mild deterioration in glycemic control. Therefore, adequate glycemic control in NAFLD patients might be important in improving NAFLD activity and preventing progression to NASH. Disclosure T.Miyake: None. Y.Hiasa: None. S.Furukawa: Speaker's Bureau; Kowa Company, Ltd., Ono Pharmaceutical Co., Ltd., Sanofi, Novo Nordisk, Eli Lilly Japan K.K. B.Matsuura: None. O.Yoshida: None. M.Miyazaki: None. A.Shiomi: None. S.Kanzaki: None. H.Nakaguchi: None. M.Abe: None.

Predictors of Nonalcoholic Steatohepatitis Severity in Obese Patients Undergoing Bariatric Surgery: A Cross-Sectional Study

Background: Nonalcoholic steatohepatitis (NASH) currently affects 3–5% of the general population and 10–50% of patients with obesity. Our aim was to determine the predictors of severity of NASH in patients with obesity undergoing sleeve gastrectomy. Methods: We conducted a retrospective study in patients with obesity who underwent sleeve gastrectomy from 2013 to 2016. Liver biopsy at the time of the surgery showed a histological grade of NASH in all the patients. Patients were stratified into two groups, mild and moderate-severe (MS) NASH. Predictors were evaluated with multivariate logistic regression. Results: We included 193 patients. Of these, 139 had mild, 22 moderate, and 36 severe NASH. Majority of patients were female (54.8%) and the mean body mass index was 40.30 ± 2.19 kg/m2. In the adjusted regression model, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) (prevalence ratios [PR]: 1.06, confidence interval [95% CI]: 1.02–1.10) and alanine aminotransferase (ALT) (PR: 1.01, 95% CI: 1.00–1.01) were factors associated with MS NASH. Conclusions: Despite the high prevalence of NASH in the obese population, most patients presented mild severity. A higher severity of NASH among patients with obesity can be predicted by clinical abnormalities such as higher HOMA-IR and ALT levels. Higher HOMA-IR levels are potential predictors of MS NASH regardless of insulin resistance status and in patients without metabolic syndrome.

Farnesyl diphosphate synthase exacerbates nonalcoholic steatohepatitis via the activation of AHR-CD36 axis.

Nonalcoholic steatohepatitis (NASH) has become a major concern that threatens human health worldwide. The underlying pathogenesis was crucial but remained poorly understood. Here, we found that the expression of hepatic farnesyl diphosphate synthase (FDPS) was increased in mice and patients with NASH. Elevated FDPS levels were positively correlated with NASH severity. Overexpression of FDPS in mice provoked increased lipid accumulation, inflammation, and fibrosis, while hepatic FDPS deficiency protected mice from NASH progression. Importantly, pharmacological inhibition of FDPS with clinically used alendronate remarkably attenuated NASH-associated phenotypes in mice. Mechanistically, we demonstrated that FDPS increased its downstream product farnesyl pyrophosphate levels, which could function as an aryl hydrocarbon receptor (AHR) agonist to upregulate the expression of fatty acid translocase CD36, to accelerate the development of NASH. Collectively, these findings suggest that FDPS exacerbates NASH via AHR-CD36 axis and identify FDPS as a promising target for NASH therapy.

Identification of ferroptosis-related genes in the progress of NASH.

Non-alcoholic steatohepatitis (NASH) is becoming more widespread, and some similarities exist between its etiology and ferroptosis. However, there are limited investigations on which ferroptosis-related genes (FRGs) are regulated in NASH and how to regulate them. We screened and validated the pivotal genes linked to ferroptosis in NASH to comprehend the function of ferroptosis in the development of NASH. Two mRNA expression data were obtained from the Gene Expression Omnibus (GEO) as the training set and validation set respectively. FRGs were downloaded from FerrDb. The candidate genes were obtained from the intersection between differentially expressed genes (DEGs) and FRGs, and further analyzed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The hub genes were identified by the protein-protein interaction (PPI) network and Cytoscape. Then, FRGs closely related to the severity of NASH were identified and further confirmed using the validation set and mouse models. Ultimately, based on these genes, a diagnostic model was established to differentiate NASH from normal tissues using another data set from GEO. A total of 327 FRGs in NASH were acquired and subjected to GSEA. And 42 candidate genes were attained by overlapping the 585 FRGs with 2823 DEGs, and enrichment analysis revealed that these genes were primarily engaged in the fatty acid metabolic, inflammatory response, and oxidative stress. A total of 10 hub genes (PTGS2、IL1B、IL6、NQO1、ZFP36、SIRT1、ATF3、CDKN1A、EGR1、NOX4) were then screened by PPI network. The association between the expression of 10 hub genes and the progress of NASH was subsequently evaluated by a training set and verified by a validation set and mouse models. CDKN1A was up-regulated along with the development of NASH while SIRT1 was negatively correlated with the course of the disease. And the diagnostic model based on CDKN1A and SIRT1 successfully distinguished NASH from normal samples. In summary, our findings provide a new approach for the diagnosis, prognosis, and treatment of NASH based on FRGs, while advancing our understanding of ferroptosis in NASH.

UDP-glucuronate metabolism controls RIPK1-driven liver damage in nonalcoholic steatohepatitis

Hepatocyte apoptosis plays an essential role in the progression of nonalcoholic steatohepatitis (NASH). However, the molecular mechanisms underlying hepatocyte apoptosis remain unclear. Here, we identify UDP-glucose 6-dehydrogenase (UGDH) as a suppressor of NASH-associated liver damage by inhibiting RIPK1 kinase-dependent hepatocyte apoptosis. UGDH is progressively reduced in proportion to NASH severity. UGDH absence from hepatocytes hastens the development of liver damage in male mice with NASH, which is suppressed by RIPK1 kinase-dead knockin mutation. Mechanistically, UGDH suppresses RIPK1 by converting UDP-glucose to UDP-glucuronate, the latter directly binds to the kinase domain of RIPK1 and inhibits its activation. Recovering UDP-glucuronate levels, even after the onset of NASH, improved liver damage. Our findings reveal a role for UGDH and UDP-glucuronate in NASH pathogenesis and uncover a mechanism by which UDP-glucuronate controls hepatocyte apoptosis by targeting RIPK1 kinase, and suggest UDP-glucuronate metabolism as a feasible target for more specific treatment of NASH-associated liver damage.

Abstract 684: Hepatic Oxalate Overproduction As A Driver And Therapeutic Target In NASH And Atherosclerosis

Affecting one third of the global population, with no pharmacotherapy available, nonalcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease. Surprisingly, the major cause of death in patients with NAFLD, particularly in those with the more severe nonalcoholic steatohepatitis (NASH), is atherosclerotic cardiovascular disease (CVD). Thus, there is a critical need to identify targetable pathways for concurrent treatment of NASH and atherosclerotic CVD, which has been hampered by limited understanding of the pathophysiology and metabolic pathways linking these two diseases. Recently, we and others uncovered oxalate metabolism commonly dysregulated in NAFLD and CVD. Using unbiased transcriptomics, we identified suppression of genes that limit oxalate production in livers from humans and mice with NASH. Alanine-glyoxylate aminotransferase (AGXT), a liver-specific enzyme that detoxifies glyoxylate, the oxalate precursor, was reduced and oxalate was markedly increased in correlation with NASH severity. Remarkably, oxalate was also increased both in patients and mice with atherosclerosis. In our mouse models of hepatic oxalate overproduction ( Agxt -/- and Agxt -/- / Apoe -/- ), both NASH and atherosclerosis were increased with suppressed hepatic fatty acid β-oxidation (FAO) and induction of proinflammatory pathways. In hepatocytes, oxalate induced mitochondrial dysfunction and lipid accumulation while downregulating peroxisome proliferator-activated receptor α (PPARα), inhibiting FAO and upregulating C-C motif chemokine ligand 5 (CCL5). Importantly, limiting hepatic oxalate production via hepatocyte-specific overexpression of AGXT (AAV8-TBG-AGXT) reduced NASH and atherosclerosis in mice by stimulating FAO and attenuating proinflammatory responses. Together, our findings uncover hepatic oxalate overproduction as a dysregulated metabolic pathway linking NASH and atherosclerotic CVD, highlighting the potential of oxalate reduction for concurrent treatment of these two prominent diseases.

Expansion of macrophage and liver sinusoidal endothelial cell subpopulations during non-alcoholic steatohepatitis progression

Liver non-parenchymal cells (NPCs) play a critical role in the progression of non-alcoholic steatohepatitis (NASH). We aimed to explore the heterogeneity of NPCs and identify NASH-specific subpopulations contributing to NASH progression. Through single-cell RNA sequencing, we uncovered a proinflammatory subpopulation of Itgadhi/Fcrl5hi macrophages with potential function of modulating macrophage accumulation and promoting NASH development. We also identified subpopulations of Egr1hi and Ly6ahi liver sinusoidal endothelial cells (LSECs), which might participate in pathological angiogenesis and inflammation regulation. The Itgadhi/Fcrl5hi macrophages, Egr1hi LSECs, and Ly6ahi LSECs emerged in the early stage and expanded significantly along with pathological progression of liver injury during NASH. Cell-cell interactions between hepatic stellate cells (HSCs) and Itgadhi/Fcrl5hi macrophages, Egr1hi LSECs or Ly6ahi LSECs were enhanced in NASH liver. Our results revealed that expansion of Itgadhi/Fcrl5hi macrophages, Egr1hi LSECs or Ly6ahi LSECs was strongly associated with NASH severity, suggesting these subpopulations might be involved in NASH progression.

High prevalence of periodontal disease in patients with NASH- possible association of poor dental health with NASH severity

Introduction and ObjectivesRecent translational research indicated a bidirectional relationship between NASH (non-alcoholic steatohepatitis) and periodontitis; however, few clinical cohorts have studied this in detail. Thus we investigated this assumed association in a well-defined cohort. Materials and MethodsData were generated prospectively for 132 patients (32 patients with NASH and 100 unselected, consecutively collected, anonymized controls from a local dental practice): detailed periodontal parameters, i.e., pocket-probing-depths (PPD), bleeding-on-probing (BOP), plaque-index, and utilization of dental care were assessed and correlated with relevant hepatic parameters (liver stiffness via fibroscan, AST, ALT, bilirubin, and MELD-score). Gingiva samples were tested for Porphyromonas gingvalis (P.g.) and Actinobacillus actinomyctemcomitans (A.a.) by PCR. Results87.5% of NASH patients and 47% of controls suffered from moderate to severe periodontitis (p=0.01). Liver stiffness was significantly correlated with elevated PPD (p=0.02) and BOP (p=0.03). 34 % of the NASH patients did not make use of regular dental health care. In these patients, AST (p=0.04), MELD score (p<0.01), and liver stiffness (p=0.01) were significantly elevated compared to those who see a dentist regularly. The severity of NASH was not associated with the intraoral detection of P.g. and A.a. ConclusionsThe present study suggests that NASH might be associated with periodontitis, irrespective of the intraoral presence of P.g. and A.a. Moreover, regular dental care utilization might mitigate the course of NASH, and patients should be reminded by their hepatologists of the importance of regular dental visits. Future studies should investigate the role of regular dental care and additional anti-inflammatory treatments of the oral cavity.

Akkermansia muciniphila suppressing nonalcoholic steatohepatitis associated tumorigenesis through CXCR6+ natural killer T cells.

Gut microbiota plays a crucial role in the development and progression of nonalcoholic steatohepatitis (NASH) and associated hepatocellular carcinoma (HCC). Akkermansia muciniphila was reported to inhibit inflammation-associated cancer in the intestine. The anti-NASH ability of A. muciniphila has recently been found. Thus, we were to investigate whether supplementation of A. muciniphila could prevent NASH-associated HCC. In a model we called STAM, male C57BL/6J mice were subcutaneously injected with 200 µg streptozotocin at 4 days after birth, and fed with high-fat diet at 4 weeks of age to induce NASH-associated HCC. Faeces from mice and patients with NASH-related HCC were collected for 16S rRNA sequencing. STAM mice were orally administered either saline or A. muciniphila twice a day starting at 4 or 10 weeks of age. The effects of A. muciniphila on the immune responses were also evaluated. Patients and mice with NASH-related HCC showed significantly reduced gut A. muciniphila in comparison to healthy controls. Administration of breast milk-isolated A. muciniphila (AM06) but not feces-isolated A. muciniphila (AM02) could improve NASH severity. Interestingly, breast milk-isolated A. muciniphila treatment suppressed the progression of NASH to HCC, accompanied with an increased hepatic CXCR6+ natural killer T (NKT) cell and decreased macrophage infiltration. The antitumor ability of A. muciniphila was not evident in NKT cell-deficient mice (CD1d-/- and CXCR6-/-). In vitro, A. muciniphila promoted the killing of hepG2 cells by NKT cells. Our study will provide the rationale for the application of A. muciniphila to treat NASH and for the prevention of its progression to HCC.

SENP1 prevents steatohepatitis by suppressing RIPK1-driven apoptosis and inflammation

Activation of RIPK1-driven cell death and inflammation play important roles in the progression of nonalcoholic steatohepatitis (NASH). However, the mechanism underlying RIPK1 activation in NASH remains unclear. Here we identified SENP1, a SUMO-specific protease, as a key endogenous inhibitor of RIPK1. SENP1 is progressively reduced in proportion to NASH severity in patients. Hepatocyte-specific SENP1-knockout mice develop spontaneous NASH-related phenotypes in a RIPK1 kinase-dependent manner. We demonstrate that SENP1 deficiency sensitizes cells to RIPK1 kinase-dependent apoptosis by promoting RIPK1 activation following TNFα stimulation. Mechanistically, SENP1 deSUMOylates RIPK1 in TNF-R1 signaling complex (TNF-RSC), keeping RIPK1 in check. Loss of SENP1 leads to SUMOylation of RIPK1, which re-orchestrates TNF-RSC and modulates the ubiquitination patterns and activity of RIPK1. Notably, genetic inhibition of RIPK1 effectively reverses disease progression in hepatocyte-specific SENP1-knockout male mice with high-fat-diet-induced nonalcoholic fatty liver. We propose that deSUMOylation of RIPK1 by SENP1 provides a pathophysiologically relevant cell death-restricting checkpoint that modulates RIPK1 activation in the pathogenesis of nonalcoholic steatohepatitis.