Rifaximin on epigenetics and autophagy in animal model of hepatocellular carcinoma secondary to metabolic-dysfunction associated steatotic liver disease.

BACKGROUND: Prevalence of hepatocellular carcinoma (HCC) is increasing, especially in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). AIM: To investigate rifaximin (RIF) effects on epigenetic/autophagy markers in animals. METHODS: Adult Sprague-Dawley rats were randomly assigned (n = 8, each) and treated from 5-16 wk: Control [standard diet, water plus gavage with vehicle (Veh)], HCC [high-fat choline deficient diet (HFCD), diethylnitrosamine (DEN) in drinking water and Veh gavage], and RIF [HFCD, DEN and RIF (50 mg/kg/d) gavage]. Gene expression of epigenetic/autophagy markers and circulating miRNAs were obtained. RESULTS: All HCC and RIF animals developed metabolic-dysfunction associated steatohepatitis fibrosis, and cirrhosis, but three RIF-group did not develop HCC. Comparing animals who developed HCC with those who did not, miR-122, miR-34a, tubulin alpha-1c (Tuba-1c), metalloproteinases-2 (Mmp2), and metalloproteinases-9 (Mmp9) were significantly higher in the HCC-group. The opposite occurred with Becn1, coactivator associated arginine methyltransferase-1 (Carm1), enhancer of zeste homolog-2 (Ezh2), autophagy-related factor LC3A/B (Map1 Lc3b), and p62/sequestosome-1 (p62/SQSTM1)-protein. Comparing with controls, Map1 Lc3b, Becn1 and Ezh2 were lower in HCC and RIF-groups (P < 0.05). Carm1 was lower in HCC compared to RIF (P < 0.05). Hepatic expression of Mmp9 was higher in HCC in relation to the control; the opposite was observed for p62/Sqstm1 (P < 0.05). Expression of p62/SQSTM1 protein was lower in the RIF-group compared to the control (P = 0.024). There was no difference among groups for Tuba-1c, Aldolase-B, alpha-fetoprotein, and Mmp2 (P > 0.05). miR-122 was higher in HCC, and miR-34a in RIF compared to controls (P < 0.05). miR-26b was lower in HCC compared to RIF, and the inverse was observed for miR-224 (P < 0.05). There was no difference among groups regarding miR-33a, miR-143, miR-155, miR-375 and miR-21 (P > 0.05). CONCLUSION: RIF might have a possible beneficial effect on preventing/delaying liver carcinogenesis through epigenetic modulation in a rat model of MASLD-HCC.

Nicotinamide riboside and dietary restriction effects on gut microbiota and liver inflammatory and morphologic markers in cafeteria diet-induced obesity in rats.

OBJECTIVES: No specific therapy is available for metabolic dysfunction-associated fatty liver disease. We investigated nicotinamide riboside (NR) and dietary restriction (DR) effects in liver lipids, inflammation, histology, intestinal permeability, and gut microbiota in a cafeteria diet (CAFD)-induced obesity model. METHODS: Adult male Wistar rats were randomly assigned to standard diet (SD) or CAFD. After 6 wk, they were subdivided into six groups-SD + vehicle (Veh) (distilled water), SD + NR (400 mg/kg), DR + Veh, DR + NR, CAFD + Veh, and CAFD + NR-for 4 wk more until euthanasia. RESULTS: CAFD increased the hepatic content of lipids, triacylglycerols, and total cholesterol and promoted hepatomegaly, steatosis, steatohepatitis, and liver fibrosis. DR intervention successfully delayed the onset of CAFD-induced liver abnormalities except for steatosis and fibrosis. CAFD suppressed Sirt1 expression in the liver and DR increased Sirt3 expression. CAFD did not affect hepatic inflammatory genes but DR enhanced Il10 expression while decreasing Il1ß expression. CAFD reduced Firmicutes and increased Bacteroidetes and Cyanobacteria, with no changes in intestinal permeability. Gut microbiota patterns in animals exposed to DR were similar to those of animals in SD. NR, specifically in CAFD, reduced hepatic triacylglycerols and total cholesterol deposition and collagen fiber accumulation in the liver and limited the colonization of CAFD-induced Cyanobacteria. NR combined with DR decreased the liver's relative weight and Tnfα expression and suppressed Sirt1 and Sirt3 hepatic expression. CONCLUSIONS: This study suggests that NR can be a potential adjuvant to metabolic dysfunction-associated fatty liver disease therapy, encouraging further research in this field.

Changes in the gut microbiota of rats after exposure to the fungicide Mancozeb.

Mancozeb is a fungicide commonly used in pest control programs, especially to protect vineyards. Its toxicity has already been evidenced in several studies. However, its influence on the composition and diversity of the gut microbiota remains unknown. In this work, the adverse impact of Mancozeb on the intestinal microbiota was investigated using a rodent model. Adult male Sprague Dawley rats were randomized into three groups: Control (standard diet), MZ1 (Mancozeb dose: 250 mg/kg bw/day), and MZ2 (Mancozeb dose: 500 mg/kg bw/day). After 12 weeks of experiment, animals were euthanized, and feces present in the intestine were collected. After fecal DNA extraction, the V4 region of the 16S rRNA gene was amplified followed by sequencing in an Ion S5™ System. Alpha and beta diversity analysis showed significant differences between Control and Mancozeb groups (MZ1 e MZ2), but no difference between MZ1 and MZ2 was observed. Seven genera significantly increased in abundance following Mancozeb exposure, while five genera decreased. Co-occurrence analyses revealed that the topological properties of the microbial networks, which can be used to infer co-occurrence interaction patterns among microorganisms, were significantly lower in both groups exposed to Mancozeb when compared to Control. In addition, 23 differentially abundant microbial metabolic pathways were identified in Mancozeb-treated groups mainly related to a change in energy metabolism, LPS biosynthesis, and nucleotide biosynthesis. In conclusion, the exposure to Mancozeb presented side effects by changing the composition of the microbiota in rats, increasing bacterial diversity regardless of the dose used, reducing the interaction patterns of the microbial communities, and changing microbial metabolic pathways.

Does the risk of cardiovascular events differ between biopsy-proven NAFLD and MAFLD?

BACKGROUND/PURPOSE: Cardiovascular disease (CVD) is the leading cause of death among individuals with non-alcoholic fatty liver disease (NAFLD). Recently, NAFLD was renamed metabolic-associated fatty liver disease (MAFLD). This study aimed to compare cardiovascular risk (CVR) and CVD between patients with NAFLD and MAFLD. METHODS: Retrospective cross-sectional study of biopsy-proven liver steatosis performed between 2013 and 2018 at a university hospital. Cases were divided into NAFLD or MAFLD and demographic, clinical, and laboratory data were collected to assess CVR (through the atherosclerotic cardiovascular disease risk estimator and atherogenic indices) and CVD. RESULTS: Out of 1233 liver biopsies, 171 (13.9%) presented steatosis. Of these, 109 patients met diagnostic criteria for NAFLD (63.7%) and 154 (90.1%), for MAFLD. In the NAFLD group, 78% of the cases had steatohepatitis, 24.8% had cirrhosis, and 3.7%, hepatocellular carcinoma (HCC). In the MAFLD group, 72.7% of the cases had liver inflammatory activity, 28.6% had cirrhosis, and 13.6% had HCC. In patients with MAFLD and NAFLD, CVR was intermediate/high (36.4 and 25.7%, p = 0.209) and CVD occurred in 20.1 and 12.8% (p = 0.137) of the cases, respectively, with no influence of liver injury severity. We observed a significant increase in high 10-year CVR (p = 0.020) and CVD (p = 0.007) in patients with MAFLD and concomitant viral infection (HCV and/or HBV) compared to cases with MAFLD only. CONCLUSION: Patients with both NAFLD and MAFLD had intermediate/high CVR, with a high rate of CVD. Patients with MAFLD and concomitant viral infection showed significantly increased CVR and CVD compared to those without viral infection.