Muscle fibre morphometric analysis (MusMA) correlates with muscle function and cardiovascular risk prognosis.

Morphometry of striated muscle fibres is critical for monitoring muscle health and function. Here, we evaluated functional parameters of skeletal and cardiac striated muscle in two experimental models using the Morphometric Analysis of Muscle Fibre tool (MusMA). The collagen-induced arthritis model was used to evaluate the function of skeletal striated muscle and the non-alcoholic fatty liver disease model was used for cardiac striated muscle analysis. After euthanasia, we used haeamatoxylin and eosin stained sections of skeletal and cardiac muscle to perform muscle fibre segmentation and morphometric analysis. Morphometric analysis classified muscle fibres into six subpopulations: normal, regular hypertrophic, irregular hypertrophic, irregular, irregular atrophic and regular atrophic. The percentage of atrophic fibres was associated with lower walking speed (p = 0.009) and lower body weight (p = 0.026), respectively. Fibres categorized as normal were associated with maximum grip strength (p < 0.001) and higher march speed (p < 0.001). In the evaluation of cardiac striated muscle fibres, the percentage of normal cardiomyocytes negatively correlated with cardiovascular risk markers such as the presence of abdominal adipose tissue (p = .003), miR-33a expression (p = .001) and the expression of miR-126 (p = .042) Furthermore, the percentage of atrophic cardiomyocytes correlated significantly with the Castelli risk index II (p = .014). MusMA is a simple and objective tool that allows the screening of striated muscle fibre morphometry, which can complement the diagnosis of muscle diseases while providing functional and prognostic information in basic and clinical research.

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.

Ornithine Aspartate and Vitamin-E Combination Has Beneficial Effects on Cardiovascular Risk Factors in an Animal Model of Nonalcoholic Fatty Liver Disease in Rats.

Cardiovascular (CV) disease is the main cause of death in nonalcoholic fatty liver disease (NAFLD), a clinical condition without any approved pharmacological therapy. Thus, we investigated the effects of ornithine aspartate (LOLA) and/or Vitamin E (VitE) on CV parameters in a steatohepatitis experimental model. Adult Sprague Dawley rats were randomly assigned (10 animals each) and treated from 16 to 28 weeks with gavage as follows: controls (standard diet plus distilled water (DW)), NAFLD (high-fat choline-deficient diet (HFCD) plus DW), NAFLD+LOLA (HFCD plus LOLA (200 mg/kg/day)), NAFLD+VitE (HFCD plus VitE (150 mg twice a week)) or NAFLD+LOLA+VitE in the same doses. Atherogenic ratios were higher in NAFLD when compared with NAFLD+LOLA+VitE and controls (p < 0.05). Serum concentration of IL-1ß, IL-6, TNF-α, MCP-1, e-selectin, ICAM-1, and PAI-1 were not different in intervention groups and controls (p > 0.05). NAFLD+LOLA decreased miR-122, miR-33a, and miR-186 (p < 0.05, for all) in relation to NAFLD. NAFLD+LOLA+VitE decreased miR-122, miR-33a and miR-186, and increased miR-126 (p < 0.05, for all) in comparison to NAFLD and NAFLD+VitE. NAFLD+LOLA and NAFLD+LOLA+VitE prevented liver collagen deposition (p = 0.006) in comparison to NAFLD. Normal cardiac fibers (size and shape) were lower in NAFLD in relation to the others; and the inverse was reported for the percentage of regular hypertrophic cardiomyocytes. NAFLD+LOLA+VitE promoted a significant improvement in atherogenic dyslipidemia, liver fibrosis, and paracrine signaling of lipid metabolism and endothelial dysfunction. This association should be further explored in the treatment of NAFLD-associated CV risk factors.

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.

Gut dysbiosis and systemic inflammation promote cardiomyocyte abnormalities in an experimental model of steatohepatitis.

BACKGROUND: Cardiovascular disease is the main cause of death in metabolic-associated fatty liver disease, and gut microbiota dysbiosis is associated with both of them. AIM: To assess the relationship between gut dysbiosis and cardiovascular risk (CVR) in an experimental model of steatohepatitis. METHODS: Adult male Sprague-Dawley rats were randomized to a control group (n = 10) fed a standard diet and an intervention group (n = 10) fed a high-fat choline-deficient diet for 16 wk. Biochemical, molecular, hepatic, and cardiac histopathology. Gut microbiota variables were evaluated. RESULTS: The intervention group had a significantly higher atherogenic coefficient, Castelli's risk index (CRI)-I and CRI-II, interleukin-1ß, tissue inhibitor of metalloproteinase-1 (all P < 0.001), monocyte chemoattractant protein-1 (P = 0.005), and plasminogen activator inhibitor-1 (P = 0.037) than the control group. Gene expression of miR-33a increased (P = 0.001) and miR-126 (P < 0.001) decreased in the intervention group. Steatohepatitis with fibrosis was seen in the intervention group, and heart computerized histological imaging analysis showed a significant decrease in the percentage of cardiomyocytes with a normal morphometric appearance (P = 0.007), reduction in the mean area of cardiomyocytes (P = 0.037), and an increase of atrophic cardiomyocytes (P = 0.007). There were significant correlations between the cardiomyocyte morphometry markers and those of progression and severity of liver disease and CVR. The intervention group had a lower Shannon diversity index and fewer changes in the structural pattern of gut microbiota (both P < 0.001) than controls. Nine microbial families that are involved in lipid metabolism were differentially abundant in intervention group and were significantly correlated with markers of liver injury and CVR. CONCLUSION: The study found a link between gut dysbiosis and significant cardiomyocyte abnormalities in animals with steatohepatitis.

Transcranial direct current stimulation (tDCS) has beneficial effects on liver lipid accumulation and hepatic inflammatory parameters in obese rats.

Obesity is key to liver steatosis development and progression. Transcranial direct current stimulation (tDCS) is a promising tool for eating disorders management but was not yet evaluated in steatosis. This study investigated tDCS' effects on liver steatosis and inflammation in an experimental obesity model. Male Wistar rats (60 days-old) were randomly allocated (n = 10/group) as follows: standard-diet/sham tDCS (SDS), standard-diet/tDCS (SDT), hypercaloric-cafeteria-diet/sham tDCS (HDS), and hypercaloric-cafeteria-diet/tDCS (HDT). After 40 days of diet, animals received active or sham tDCS for eight days and were euthanized for liver fat deposition and inflammation analysis. HDS and HDT animals showed cumulative food consumption, total liver lipid deposits, IL-1ß, TNF-α levels, IL-1ß/IL-10 and TNF-α/IL-10 ratios significantly higher than the SDS and SDT groups (p < 0.001 for all parameters). tDCS (SDT and HDT) reduced liver lipid deposits (0.7 times for both, p < 0.05), IL-1ß (0.7 times and 0.9 times, respectively, p < 0.05) and IL-1ß/IL-10 index (0.6 times and 0.8 times, respectively, p < 0.05) in relation to sham (SDS and HDS). There was an interaction effect on the accumulation of hepatic triglycerides (p < 0.05). tDCS reduced 0.8 times the average liver triglyceride concentration in the HDT vs. HDS group (p < 0.05). In this obesity model, tDCS significantly decreased liver steatosis and hepatic inflammation. These results may justify looking into tDCS utility for human steatosis.