Reduced Liver Steatosis Research Articles

Metformin’s effect on metabolic dysfunction-associated steatotic liver disease through the miR-200a-5p and AMPK/SERCA2b pathway

IntroductionMetformin has shown benefits in treating metabolic dysfunction-associated steatotic liver disease (MASLD), but its mechanisms remain unclear. This study investigates miR-200a-5p’s role in the AMPK/SERCA2b pathway to reduce liver fat accumulation and ER stress in MASLD.MethodsA PA cell model induced by palmitic and oleic acids (2:1) was used to assess lipid accumulation via Oil Red O and Nile Red staining. mRNA levels of miR-200a-5p and lipid metabolism genes were measured with RT-PCR, and AMPK, p-AMPK, and SERCA2b protein levels were analyzed by Western blotting. The interaction between miR-200a-5p and AMPK was studied using a luciferase reporter assay. A high-fat diet-induced MASLD mouse model was used to evaluate metformin’s effects on liver steatosis and lipid profiles. Serum miR-200a-5p levels were also analyzed in MASLD patients.ResultsIn the PA cell model, elevated miR-200a-5p and lipid metabolism gene mRNA levels were observed, with decreased AMPK and SERCA2b protein levels. miR-200a-5p mimic reduced AMPK and SERCA2b expression. Metformin treatment reduced liver steatosis and lipid deposition in mice, normalizing miR-200a-5p, lipid metabolism gene mRNA, and AMPK/SERCA2b protein levels. Elevated serum miR-200a-5p was detected in MASLD patients.DiscussionThese findings suggest that metformin alleviates lipid deposition and ER stress in MASLD through the modulation of the AMPK/SERCA2b pathway via miR-200a-5p.

Effects of dapagliflozin on liver steatosis in patients with nonalcoholic fatty liver disease: a randomized controlled trial.

Nonalcoholic fatty liver disease (NAFLD) is a common liver comorbidity with considerable global consequences. This study explores the efficacy of dapagliflozin, a sodium-glucose cotransporter 2 inhibitor primarily used to manage type 2 diabetes, in reducing liver steatosis among NAFLD patients. This randomized, open-label, two-arm, parallel-group trial enrolled patients with NAFLD and a controlled attenuation parameter (CAP) score of ≥ 252dB/m. Participants were randomized (1:1) into either the control or dapagliflozin groups. The primary outcome was the change in CAP scores, measured with FibroScan after 24weeks. The trial included 150 patients, 20 of whom (13%) had type 2 diabetes. In week 24, the dapagliflozin group had significantly lower CAP score and fatty liver grade than did the control group (266.3 ± 57.8 50 vs 298.6 ± 59.0dB/m, respectively [p = 0.002]; 1.7 ± 0.7 vs 2.2 ± 0.8, respectively [p < 0.001]). Liver stiffness, waist circumference, and alanine transaminase levels decreased in both the dapagliflozin and control groups, but the between-group differences were nonsignificant (1.0 ± 0.3 vs 1.1 ± 0.3 [p = 0.678], 94.2 ± 12.7 vs 92.4 ± 11.1 [p = 0.382], and 28.8 ± 18.3 vs 28.3 ± 14.2 U/L [p = 0.856], respectively). In the multivariate analysis, a reduction in CAP was associated with dapagliflozin treatment (p = 0.01) and changes in BMI (p = 0.007). No adverse events were observed. Dapagliflozin can reduce CAP score and fatty liver grade in patients with moderate to severe NAFLD, regardless of their diabetes status.

PAMK Ameliorates Non-Alcoholic Steatohepatitis and Associated Anxiety/Depression-like Behaviors Through Restoring Gut Microbiota and Metabolites in Mice.

Long-term Western diet-induced non-alcoholic steatohepatitis (NASH) can lead to liver cirrhosis and NASH-associated hepatocellular carcinoma, which are end-stage liver diseases. Meanwhile, NASH is associated with mental burden and worsens as the disease progresses. Atractylodes Macrocephala Koidz (AMK) is one of the main ingredients of Shenling Baizhu San, and the effect of Polysaccharide from AMK ameliorates (PAMK), as an important medicinal ingredient of AMK, on NASH and associated anxiety/depression-like behaviors is still unclear. This study investigated the protective effect of PAMK on NASH and associated anxiety/depression-like behaviors through a Western diet-induced NASH mice model. showed that PAMK decreased the concentrations of liver TC, TG, and serum AST and ALT, improving glucose tolerance, and reducing liver steatosis and fibrosis. Moreover, the expression of liver IL-6, IL-1β, TNF-α, IL-18 and MCP-1 could be reduced by PAMK significantly. Additionally, PAMK decreased anxiety/depression-like behaviors and expression of IL-6, IL-1β, TNF-α, and MCP-1 in the hippocampus. 16S rRNA gene sequencing revealed that PAMK diminished the Firmicutes/Bacteroidetes ratio and abundance of Faecalibaculum_rodentium, and increased the abundance of Muribaculaceae. This might be related to gene abundance of Pentose, the glucuronate interconversions pathway and carbohydrate enzymes (GH1, GH4). Serum metabolomics suggested that PC (18:5e/2:0), PC (16:2e/2:0), Lysopc 20:4, PC (16:0/2:0), and LPC 19:0 upregulated significantly after PAMK intervention, together with the enrichment of carbon metabolism and Citrate cycle pathways specially. PAMK as a potential prebiotic ameliorated NASH and associated anxiety/depression-like behaviors in mice, probably by regulating Faecalibaculum_rodentium, carbohydrate enzymes and lipid metabolites.

The Effects of Testosterone Replacement Therapy in Adult Men with Metabolic Dysfunction associated Steatotic Liver Disease: A Systematic Review and Meta-analysis.

Sex steroids modulate metabolic-dysfunction associated steatotic liver disease (MASLD) pathobiology. We hypothesized that testosterone therapy (TT) modulates progression of MASLD, and performed a systematic review to evaluate the efficacy of TT on liver steatosis and fibrosis. We searched PubMed and Embase from inception until November 2023. We screened 1489 studies and identified 9 eligible studies. We assessed risk of bias for randomized trials using RoB-2 "Cochrane risk of bias tool for randomized trials", non-randomized studies using ROBINS-I tool "Risk of Bias in Non-randomized Studies-of Interventions", and Murad's Tool for single-arm studies. We pooled estimates using RevMan 5. 3 randomized controlled trials (RCTs), 4 non-randomized studies, and 2 single-arm studies were identified. The population of interest comprised men with MASLD. TT was administered at varying doses, routes, and frequencies, with follow-up ranging 12-weeks to 8-years. Liver fibrosis and steatosis were assessed using liver biopsy in 3 studies, CT/MRI in 5, and serum scores in 2. All studies provided evidence of reduction in liver steatosis with TT compared to no TT. In addition, the LiFT (RCT) trial demonstrated a resolution of MASLD / MASH and a regression in liver fibrosis. TT led to decrease in liver enzymes. Studies were heterogenous in terms of population characteristics, treatment modalities, endpoints, and follow-up. Adverse events were comparable between the 2 groups. TT is a promising treatment option for men with MASLD and low testosterone. It may improve liver steatosis and reduce liver fibrosis. Large, double-blinded randomized placebo-controlled trials are needed.

Effects of sodium-glucose contrasporter-2 inhibitors and glucagon-like peptide-1 receptor agonists on arterial stiffness, coronary flow reserve and liver steatosis in diabetes

Abstract Background Patients with type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD) present an increased risk of cardiovascular disease. Sodium-glucose contrasporter-2 inhibitors (SGLT-2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) have been shown to significantly decrease the risk of cardiovascular complications. Purpose The aim of the study was to investigate the effect of treatment with SGLT-2i or GLP-1RA on cardiovascular function and liver steatosis and fibrosis in patients with T2DM and NAFLD. Methods Forty patients with T2DM and NAFLD (mean age: 58 ± 11 years) were randomized to receive SGLT-2i (dapagliflozin; n = 20) or GLP-1RA (dulaglutide; n = 20). At baseline and after 6 and 12 months of treatment, we measured: (1) perfused boundary region (PBR) of the sublingual microvessels with a diameter 5-25μm using Sidestream Dark Field camera (Microscan, Glycocheck). Increased PBR indicates reduced glycocalyx thickness. (2) Pulse wave velocity (PWV) using Complior (ALAM Medical), (3) coronary flow reserve (CFR) using Doppler echocardiography, (4) LV global longitudinal strain (GLS) using speckle-tracking echocardiography, (5) controlled attenuation parameter (CAP) score to assess steatosis grade and liver stiffness (E) to evaluate fibrosis score using liver elastography (FibroScan, Echosens), and (6) NAFLD fibrosis score (NFS). Results At baseline, patients between the two groups had similar age, sex, HbA1c, steatosis grade, fibrosis score and markers of cardiovascular function (p &amp;gt; 0.05). Compared with baseline, all patients had reduced PBR, PWV, CAP, E and NFS and increased CFR and GLS (p &amp;lt; 0.01) after 12-month treatment. In the whole study population, the percentage reduction of CAP and NFS was correlated with the corresponding decrease of PBR (r = 0.248 and r = 0.387), PWV (r = 0.290 and r = 0.281) and with the increase of GLS (r = -0.320 and r = -0.295) after 12-month treatment (p &amp;lt; 0.05 for all correlations). Both treatments with SGLT-2i and GLP-1RA reduced markers of liver steatosis and fibrosis (Table). Conclusion Both treatments with SGLT-2i and GLP-1RA improve cardiovascular function and reduce liver steatosis in patients with T2DM and NAFLD after 12 months.

The effect of 6-month treatment with coenzyme Q10 on endothelial, vascular and myocardial function in patients with nonalcoholic fatty liver disease

Abstract Background Patients with Non-alcoholic fatty liver disease (NAFLD) hold an increased cardiovascular risk and present impaired markers of vascular, endothelial and myocardial function. Coenzyme Q10 (CQ10) is a powerful antioxidant that enhances mitochondrial function. Patients/methods: 52 patients (52±10 years old) with NAFLD were randomized to 240 mg CQ10 (n=25) or placebo (n=27). We measured at baseline and at six months post-treatment: i) Perfused boundary Region (PBR) of the sublingual arterial microvessels (Microscan, Glycocheck), ii) Carotid femoral pulse wave velocity - PWV (Complior ALAM), iii) Flow-mediated dilation (FMD) of the brachial artery, iv) Global left ventricular longitudinal strain (GLS) by speckle tracking imaging, v) Controlled attenuation parameter (CAP) measurement (FibroScan, Echosens). Results Six months post treatment with cQ10, values of PBR (2.12±0.19 vs. 2.28±0.23 μm), PWV (9.5±2.3 vs. 10.5±2.4m/s), CAP score (278.1±50, 2 vs. 305.3±44.5dB/m), FMD (6.61±4 vs. 5.02±2.6 %) and GLS (-19.3±1.9 vs -18.2±2 %) were improved (p&amp;lt;0.05 for all comparisons). On the contrary, the patients who were treated with placebo did not show statistically significant differences in PBR, PWV, CAP score, FMD and GLS after from 6 months (p&amp;gt;0.05). In the patients who received cQ10, the percentage reduction of CAP score at 6 months was directly proportional to the percent reduction in PWV (r=0.31, p=0.045) and inversely proportional to the percentage increase in FMD (r=-0.58, p=0.014). Conclusion Six-month treatment with CoQ10 reduces liver steatosis in patients with NAFLD. CoQ10 is associated with improved endothelial, vascular and LV myocardial function in patients with NAFLD.

Modulation of SIRT6 related signaling pathways of p-AKT/mTOR and NRF2/HO-1 by memantine contributes to curbing the progression of tamoxifen/HFD-induced MASH in rats

Metabolic dysfunction-associated steatohepatitis (MASH) is a chronic liver disorder marked by hepatic fat accumulation and inflammatory infiltrates which may evolve to cirrhosis. Clinical studies have demonstrated the higher risk of MASH development after tamoxifen (TAM) therapy, especially in obese patients. Therefore, we aimed to evaluate MASH induction by TAM combined with high fat diet (HFD) and the potential interference of memantine (MEMA) with MASH progression via modulation of SIRT6 and its related signaling pathways. MASH was induced in female Wistar rats by co-administration of TAM (25 mg/kg/day, p.o.) and HFD for 5 weeks. Liver function biomarkers, tissue triglyceride and cholesterol, MASH scoring, SIRT6 with its related signals, and lipid synthesis/oxidation markers were estimated. By comparison to MASH group, MEMA improved liver function indices (ALT, AST, ALP, albumin) and reduced the progression of MASH, evidenced by decreased accumulation of lipids in hepatic tissue, improved histological features, and reduced MASH scoring. MEMA enhanced hepatic SIRT6 and downregulated p-AKT/mTOR signaling, that subsequently reduced expressions of the lipid synthesis biomarkers (SREBP1c, SCD), while elevating the lipid oxidation markers (PPAR-α, CPT1). Moreover, MEMA enhanced NRF2/HO-1 signaling, with subsequently improved antioxidant defense and pro-inflammatory/anti-inflammatory cytokines balance. Analysis of SIRT6 correlations with p-AKT/mTOR, NRF2/HO-1, SREBP1c, and PPAR-α further confirmed our results. Consequently, we conclude that MEMA could interfere with MASH progression, at least in part, via enhanced SIRT6 expression and modulation of its related p-AKT/mTOR and NRF2/HO-1 signaling pathways, eventually reducing liver steatosis and inflammation. That could be a promising therapeutic modality for curbing MASH progression.

Non-mitogenic FGF19 mRNA-based therapy for the treatment of experimental metabolic dysfunction-associated steatotic liver disease (MASLD).

Metabolic dysfunction-associated steatohepatitis (MASH) represents a global health threat. MASH pathophysiology involves hepatic lipid accumulation and progression to severe conditions like cirrhosis and, eventually, hepatocellular carcinoma. Fibroblast growth factor (FGF)-19 has emerged as a key regulator of metabolism, offering potential therapeutic avenues for MASH and associated disorders. We evaluated the therapeutic potential of non-mitogenic (NM)-FGF19 mRNA formulated in liver-targeted lipid nanoparticles (NM-FGF19-mRNAs-LNPs) in C57BL/6NTac male mice with diet-induced obesity and MASH (DIO-MASH: 40% kcal fat, 20% kcal fructose, 2% cholesterol). After feeding this diet for 21 weeks, NM-FGF19-mRNAs-LNPs or control (C-mRNA-LNPs) were administered (0.5 mg/kg, i.v.) weekly for another six weeks, in which diet feeding continued. NM-FGF19-mRNAs-LNPs treatment in DIO-MASH mice resulted in reduced body weight, adipose tissue depots, and serum transaminases, along with improved insulin sensitivity. Histological analyses confirmed the reversal of MASH features, including steatosis reduction without worsening fibrosis. NM-FGF19-mRNAs-LNPs reduced total hepatic bile acids (BAs) and changed liver BA composition, markedly influencing cholesterol homeostasis and metabolic pathways as observed in transcriptomic analyses. Extrahepatic effects included the down-regulation of metabolic dysfunction-associated genes in adipose tissue. This study highlights the potential of NM-FGF19-mRNA-LNPs therapy for MASH, addressing both hepatic and systemic metabolic dysregulation. NM-FGF19-mRNA demonstrates efficacy in reducing liver steatosis, improving metabolic parameters, and modulating BA levels and composition. Given the central role played by BA in dietary fat absorption, this effect of NM-FGF19-mRNA may be mechanistically relevant. Our study underscores the high translational potential of mRNA-based therapies in addressing the multifaceted landscape of MASH and associated metabolic perturbations.

Effect of Saccharomyces boulardii on Liver Diseases: A Systematic Review.

We aimed to systematize the results of published studies on the use of Saccharomyces boulardii (SB) for the treatment of various liver disorders (CRD42022378050). Searches were conducted using PubMed and Scopus on 1 August 2022. The PubMed search was updated on 15 June 2024. The review included sixteen studies: ten experimental animal studies (EASs) and six randomized controlled trials (RCTs). The CNCM I-745 strain was used in 68.8% of the included studies. SB reduced the severity of many manifestations of cirrhosis, and lowered the Child-Pugh scores in RCT. SB reduced the serum concentrations of TNF-α, IL-1β, IL-6, and IL-4 in animals with metabolic dysfunction-associated steatotic liver disease (MASLD); lowered the serum TNF-α and IL-6 levels in experimental cirrhosis in rats; and reduced the CRP levels in decompensated cirrhosis. The EAS of MASLD revealed that SB reduced liver steatosis and inflammation and lowered the liver expression of genes of TNF-α, IL-1β, interferon-γ, and IL-10. In studies on experimental cirrhosis and MASLD, SB reduced the liver expression of genes of TGF-β, α-SMA, and collagen as well as liver fibrosis. SB reduced the abundance of Escherichia (Proteobacteria), increased the abundance of Bacteroidetes in the gut microbiota, prevented an increase in intestinal barrier permeability, and reduced bacterial translocation and endotoxemia.

Protective Effects of Hepatocyte Stress Defenders, Nrf1 and Nrf2, against MASLD Progression.

Progression of metabolic dysfunction-associated steatites liver disease (MASLD) to steatohepatitis (MASH) is driven by stress-inducing lipids that promote liver inflammation and fibrosis, and MASH can lead to cirrhosis and hepatocellular carcinoma. Previously, we showed coordinated defenses regulated by transcription factors, nuclear factor erythroid 2-related factor-1 (Nrf1) and -2 (Nrf2), protect against hepatic lipid stress. Here, we investigated protective effects of hepatocyte Nrf1 and Nrf2 against MASH-linked liver fibrosis and tumorigenesis. Male and female mice with flox alleles for genes encoding Nrf1 (Nfe2l1), Nrf2 (Nfe2l2), or both were fed a MASH-inducing diet enriched with high fat, fructose, and cholesterol (HFFC) or a control diet for 24-52 weeks. During this period, hepatocyte Nrf1, Nrf2, or combined deficiency for ~7 days, ~7 weeks, and ~35 weeks was induced by administering mice hepatocyte-targeting adeno-associated virus (AAV) expressing Cre recombinase. The effects on MASH, markers of liver fibrosis and proliferation, and liver tumorigenesis were compared to control mice receiving AAV-expressing green fluorescent protein. Also, to assess the impact of Nrf1 and Nrf2 induction on liver fibrosis, HFFC diet-fed C57bl/6J mice received weekly injections of carbon tetrachloride, and from week 16 to 24, mice were treated with the Nrf2-activating drug bardoxolone, hepatocyte overexpression of human NRF1 (hNRF1), or both, and these groups were compared to control. Compared to the control diet, 24-week feeding with the HFFC diet increased bodyweight as well as liver weight, steatosis, and inflammation. It also increased hepatocyte proliferation and a marker of liver damage, p62. Hepatocyte Nrf1 and combined deficiency increased liver steatosis in control diet-fed but not HFFC diet-fed mice, and increased liver inflammation under both diet conditions. Hepatocyte Nrf1 deficiency also increased hepatocyte proliferation, whereas combined deficiency did not, and this also occurred for p62 level in control diet-fed conditions. In 52-week HFFC diet-fed mice, 35 weeks of hepatocyte Nrf1 deficiency, but not combined deficiency, resulted in more liver tumors in male mice, but not in female mice. In contrast, hepatocyte Nrf2 deficiency had no effect on any of these parameters. However, in the 15-week CCL4-exposed and 24-week HFFC diet-fed mice, Nrf2 induction with bardoxolone reduced liver steatosis, inflammation, fibrosis, and proliferation. Induction of hepatic Nrf1 activity with hNRF1 enhanced the effect of bardoxolone on steatosis and may have stimulated liver progenitor cells. Physiologic Nrf1 delays MASLD progression, Nrf2 induction alleviates MASH, and combined enhancement synergistically protects against steatosis and may facilitate liver repair.

GSDME promotes MASLD by regulating pyroptosis, Drp1 citrullination-dependent mitochondrial dynamic, and energy balance in intestine and liver.

Dysregulated metabolism, cell death, and inflammation contribute to the development of metabolic dysfunction-associated steatohepatitis (MASH). Pyroptosis, a recently identified form of programmed cell death, is closely linked to inflammation. However, the precise role of pyroptosis, particularly gasdermin-E (GSDME), in MASH development remains unknown. In this study, we observed GSDME cleavage and GSDME-associated interleukin-1β (IL-1β)/IL-18 induction in liver tissues of MASH patients and MASH mouse models induced by a choline-deficient high-fat diet (CDHFD) or a high-fat/high-cholesterol diet (HFHC). Compared with wild-type mice, global GSDME knockout mice exhibited reduced liver steatosis, steatohepatitis, fibrosis, endoplasmic reticulum stress, lipotoxicity and mitochondrial dysfunction in CDHFD- or HFHC-induced MASH models. Moreover, GSDME knockout resulted in increased energy expenditure, inhibited intestinal nutrient absorption, and reduced body weight. In the mice with GSDME deficiency, reintroduction of GSDME in myeloid cells-rather than hepatocytes-mimicked the MASH pathologies and metabolic dysfunctions, as well as the changes in the formation of neutrophil extracellular traps and hepatic macrophage/monocyte subclusters. These subclusters included shifts in Tim4+ or CD163+ resident Kupffer cells, Ly6Chi pro-inflammatory monocytes, and Ly6CloCCR2loCX3CR1hi patrolling monocytes. Integrated analyses of RNA sequencing and quantitative proteomics revealed a significant GSDME-dependent reduction in citrullination at the arginine-114 (R114) site of dynamin-related protein 1 (Drp1) during MASH. Mutation of Drp1 at R114 reduced its stability, impaired its ability to redistribute to mitochondria and regulate mitophagy, and ultimately promoted its degradation under MASH stress. GSDME deficiency reversed the de-citrullination of Drp1R114, preserved Drp1 stability, and enhanced mitochondrial function. Our study highlights the role of GSDME in promoting MASH through regulating pyroptosis, Drp1 citrullination-dependent mitochondrial function, and energy balance in the intestine and liver, and suggests that GSDME may be a potential therapeutic target for managing MASH.

Six-month supplementation with high dose coenzyme Q10 improves liver steatosis, endothelial, vascular and myocardial function in patients with metabolic-dysfunction associated steatotic liver disease: a randomized double-blind, placebo-controlled trial

BackroundMetabolic-dysfunction Associated Steatotic Liver Disease (MASLD) has been associated with increased cardiovascular risk. The aim of this Randomized Double-blind clinical Trial was to evaluate the effects of coenzyme-Q10 supplementation in patients with MASLD in terms of endothelial, vascular and myocardial function.MethodsSixty patients with MASLD were randomized to receive daily 240 mg of coenzyme-Q10 or placebo. At baseline and at 6-months, the a)Perfused boundary region of sublingual vessels using the Sideview Darkfield imaging technique, b)pulse-wave-velocity, c)flow-mediated dilation of the brachial artery, d)left ventricular global longitudinal strain, e)coronary flow reserve of the left anterior descending coronary artery and f)controlled attenuation parameter for the quantification of liver steatosis were evaluated.ResultsSix months post-treatment, patients under coenzyme-Q10 showed reduced Perfused boundary region (2.18 ± 0.23vs.2.29 ± 0.18 μm), pulse-wave-velocity (9.5 ± 2vs.10.2 ± 2.3 m/s), controlled attenuation parameter (280.9 ± 33.4vs.304.8 ± 37.4dB/m), and increased flow-mediated dilation (6.1 ± 3.8vs.4.3 ± 2.8%), global longitudinal strain (-19.6 ± 1.6vs.-18.8 ± 1.9%) and coronary flow reserve (3.1 ± 0.4vs.2.8 ± 0.4) compared to baseline (p < 0.05). The placebo group exhibited no improvement during the 6-month follow-up period (p > 0.05). In patients under coenzyme-Q10, the reduction in controlled attenuation parameter score was positively related to the reduction in Perfused boundary region and pulse wave velocity and reversely related to the increase in coronary flow reserve and flow-mediated dilation (p < 0.05 for all relations).ConclusionsSix-month treatment with high-dose coenzyme-Q10 reduces liver steatosis and improves endothelial, vascular and left ventricle myocardial function in patients with MASLD, demonstrating significant improvements in micro- and macro-vasculature function.Trial RegistrationNCT05941910

GLP-1 Receptor Agonist Treatment Improves Fasting and Postprandial Lipidomic Profiles Independently of Diabetes and Weight Loss.

Treatment with glucagon-like peptide-1 receptor agonists (GLP-1RAs) reduces liver steatosis and cardiometabolic risk (CMR). Only few data are available on lipid metabolism and no information on the postprandial lipidomic profile. Thus, we investigated how exenatide treatment changes lipid metabolism and composition during fasting and after a meal tolerance test (MTT) in adults with severe obesity without diabetes. Thirty individuals (26F/4M, 30-60 years old, BMI>40 kg/m2, HbA1c=5.76%) were assigned (1:1) to diet with exenatide treatment (EXE, n=15, 10 μg twice-daily) or without treatment as control (CT, n=15) for 3 months. Fasting and postprandial lipidomic profile (by LC/MS-QTOF) and fatty acid metabolism (following a 6-hour MTT/tracer study) and composition (by GC/MS) were evaluated before and after treatment. Both groups had slight weight loss (EXE: -5.5% vs CT: -1.9%, p=0.052). During fasting, exenatide, compared to CT, reduced some ceramides (CER) and lysophosphocholines (LPC) previously associated with CMR, while relatively increasing unsaturated phospholipid species (PC, LPC) with protective effects on CMR, although concentrations of total lipid species were unchanged. During MTT, both groups suppressed lipolysis equally to baseline, but EXE exenatide significantly lowered free fatty acid clearance and postprandial triacyclglycerols (TAG) concentrations, particularly saturated TAGs with 44-54 carbons. Exenatide also reduced some postprandial CERs, PCs, LPCs previously linked to cardiometabolic risk. These changes in lipidomic profile remained statistically significant after adjusting for weight loss. Exenatide improved fasting and postprandial lipidomic profile associated with CMR mainly by reducing saturated postprandial TAGs and CERs, independently of weight loss and diabetes.

Combined Exercise and Diet Induce Airway Hyperreactivity While Reducing Liver Steatosis in Mice with Diet-Induced Obesity.

Obesity is a multi-organ system disease, which is associated with, e.g., a higher prevalence of non-alcoholic fatty liver disease (NAFLD) and asthma. Little is known regarding the effect of obesity-related parameters (including liver integrity) and the respiratory phenotype after a combination of physical activity and diet. Thirty-two C57BL/6 mice were, after 27 weeks of a high fat diet (HFD), randomly assigned to two dietary interventions for three weeks: a HFD or a normal chow diet (NCD). In both dietary groups, half of the animals were subjected to a sub-maximal exercise protocol. Lung function, lung inflammation, liver histology, and metabolic profile were determined. Mice with obesity did not show airway hyperreactivity after methacholine provocation. Sub-maximal exercise with diet (NCD/E) induced a significant reduction in forced expiratory volume in 0.1 s after methacholine provocation. NCD/E had significantly more neutrophils and inflammation (IFN-γ, TNF-α, IL-4, and IL-17F) in bronchoalveolar lavage compared to non-exercising mice on a HFD (HFD/NE). However, more epithelial injury (serum surfactant protein D and IL-33) was seen in HFD/NE. Additionally, hepatic steatosis and fibrosis were reduced by combined diet and sub-maximal exercise. Combining sub-maximal exercise with diet induced airway hyperreactivity and pulmonary inflammation, while body weight, hepatic steatosis, and fibrosis improved.

An orphan to the rescue of obesity and steatotic liver?

In a recent article, Leeson-Payne et al. demonstrate that GPR75 knock-out in mice results in lower body fat and reduced hepatic lipid accumulation, with an increase in physical activity and energy expenditure. Loss-of-function (LoF) GPR75 variants in the UK Biobank (UKBB) are associated with reduced liver steatosis, suggesting potential therapeutic implications in metabolic dysfunction-associated steatotic liver disease (MASLD).

Environmental Enrichment Prevents Gut Dysbiosis Progression and Enhances Glucose Metabolism in High-Fat Diet-Induced Obese Mice.

Obesity is a global health concern implicated in numerous chronic degenerative diseases, including type 2 diabetes, dyslipidemia, and neurodegenerative disorders. It is characterized by chronic low-grade inflammation, gut microbiota dysbiosis, insulin resistance, glucose intolerance, and lipid metabolism disturbances. Here, we investigated the therapeutic potential of environmental enrichment (EE) to prevent the progression of gut dysbiosis in mice with high-fat diet (HFD)-induced metabolic syndrome. C57BL/6 male mice with obesity and metabolic syndrome, continuously fed with an HFD, were exposed to EE. We analyzed the gut microbiota of the mice by sequencing the 16s rRNA gene at different intervals, including on day 0 and 12 and 24 weeks after EE exposure. Fasting glucose levels, glucose tolerance, insulin resistance, food intake, weight gain, lipid profile, hepatic steatosis, and inflammatory mediators were evaluated in serum, adipose tissue, and the colon. We demonstrate that EE intervention prevents the progression of HFD-induced dysbiosis, reducing taxa associated with metabolic syndrome (Tepidimicrobium, Acidaminobacteraceae, and Fusibacter) while promoting those linked to healthy physiology (Syntrophococcus sucrumutans, Dehalobacterium, Prevotella, and Butyricimonas). Furthermore, EE enhances intestinal barrier integrity, increases mucin-producing goblet cell population, and upregulates Muc2 expression in the colon. These alterations correlate with reduced systemic lipopolysaccharide levels and attenuated colon inflammation, resulting in normalized glucose metabolism, diminished adipose tissue inflammation, reduced liver steatosis, improved lipid profiles, and a significant reduction in body weight gain despite mice's continued HFD consumption. Our findings highlight EE as a promising anti-inflammatory strategy for managing obesity-related metabolic dysregulation and suggest its potential in developing probiotics targeting EE-modulated microbial taxa.

FK506-Binding Protein 51 (FKBP51) Suppresses PPARα Activity and Shifts the Insulin Receptor Alternative Splicing Driving Hepatic Insulin Resistance

FK506-binding protein-51 (FKBP51) is a molecular chaperone protein that has great potential to serve as a treatment target for non-alcoholic fatty liver disease (NAFLD) and type II diabetes (T2DM). FKBP51 has been known to regulate nuclear receptors such as glucocorticoid receptor (GR) and peroxisome proliferator-activated receptor γ (PPARγ). However, the connections between FKBP51 and other PPAR family members, such as peroxisome proliferator-activated receptor α (PPARα), are yet to be identified. FKBP51 can also inhibit protein kinase B (AKT) activation, which may impact the insulin receptor signaling pathway. It has been reported that FKBP51 knockout mice presented less adiposity, reduced liver steatosis, and increased insulin sensitivity and insulin clearance, indicating that FKBP51 plays a role in insulin resistance and fatty liver development. However, how FKBP51 regulates insulin resistance, especially in the liver, still needs to be unveiled. It has been shown that insulin receptor (IR) alternative splicing is associated with insulin sensitivity and that PPARα activation is critical in reducing insulin resistance. Thus, we hypothesize that FKBP51 can regulate hepatic insulin resistance through insulin receptor alternative splicing and PPARα suppression. To test this hypothesis, we developed an FKBP51 knockout mouse hepatocyte cell line, 51KO AML12, and treated the cells with insulin for 1hr. We measured RNA and protein expressions in the cells through RT-PCR and western blotting and found that 51KO AML12 had increased phospho-AKT Ser473 (pAKT S473) and IR isoform B (IR-B), indicating increased insulin signaling activity. We also found increased IR isoform A (IR-A) and IR-B expression in 51KO AML12. In addition, we found an increased ratio of IR-B: IR-A in 51KO AML12 treated with insulin. These data indicate a great potential for FKBP51 to be a novel treatment target for hepatic insulin resistance and T2DM. This research is supported by the National Institute of Health R01DK121797 (T.D.H.), R01DA058933 (T.D.H.), and Start-Up funds from the University of Kentucky (T.D.H.). 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.

L-carnitine and Ginkgo biloba Supplementation In Vivo Ameliorates HCD-Induced Steatohepatitis and Dyslipidemia by Regulating Hepatic Metabolism.

Treatment strategies for steatohepatitis are of special interest given the high prevalence of obesity and fatty liver disease worldwide. This study aimed to investigate the potential therapeutic mechanism of L-carnitine (LC) and Ginkgo biloba leaf extract (GB) supplementation in ameliorating the adverse effects of hyperlipidemia and hepatosteatosis induced by a high-cholesterol diet (HCD) in an animal model. The study involved 50 rats divided into five groups, including a control group, a group receiving only an HCD, and three groups receiving an HCD along with either LC (300 mg LC/kg bw), GB (100 mg GB/kg bw), or both. After eight weeks, various parameters related to lipid and glucose metabolism, antioxidant capacity, histopathology, immune reactivity, and liver ultrastructure were measured. LC + GB supplementation reduced serum total cholesterol, triglyceride, low-density lipoprotein cholesterol, glucose, insulin, HOMA-IR, alanine transaminase, and aspartate transaminase levels and increased high-density lipoprotein cholesterol levels compared with those in the HCD group. Additionally, treatment with both supplements improved antioxidant ability and reduced lipid peroxidation. The histological examination confirmed that the combination therapy reduced liver steatosis and fibrosis while also improving the appearance of cell organelles in the ultrastructural hepatocytes. Finally, the immunohistochemical analysis indicated that cotreatment with LC + GB upregulated the immune expression of GLP-1 and β-Cat in liver sections that were similar to those of the control animals. Mono-treatment with LC or GB alone substantially but not completely protected the liver tissue, while the combined use of LC and GB may be more effective in treating liver damage caused by high cholesterol than either supplement alone by regulating hepatic oxidative stress and the protein expression of GLP-1 and β-Cat.

A study on the treatment effects of Crataegus pinnatifida polysaccharide on non-alcoholic fatty liver in mice by modulating gut microbiota.

The objective of this study was to investigate the protective effect of Crataegus pinnatifida polysaccharide (CPP) on non-alcoholic fatty liver disease (NAFLD) induced by a high-fat diet (HFD) in mice. The findings demonstrated that CPP improved free fatty acid (FFA)-induced lipid accumulation in HepG2 cells and effectively reduced liver steatosis and epididymal fat weight in NAFLD mice, as well as decreased serum levels of TG, TC, AST, ALT, and LDL-C. Furthermore, CPP exhibited inhibitory effects on the expression of fatty acid synthesis genes FASN and ACC while activating the expression of fatty acid oxidation genes CPT1A and PPARα. Additionally, CPP reversed disturbances in intestinal microbiota composition caused by HFD consumption. CPP decreased the firmicutes/Bacteroidetes ratio, increased Akkermansia abundance, and elevated levels of total short-chain fatty acid (SCFA) content specifically butyric acid and acetic acid. Our results concluded that CPP may intervene in the development of NAFLD by regulating of intes-tinal microbiota imbalance and SCFAs production. Our study highlights that CPP has a potential to modulate lipid-related pathways via alterations to gut microbiome composition thereby ex-erting inhibitory effects on obesity and NAFLD development.

Effects of NPY-2 Receptor Antagonists, Semaglutide, PYY3-36, and Empagliflozin on Early MASLD in Diet-Induced Obese Rats.

(1) Background: Modulators of the Neuropeptide Y (NPY) system are involved in energy metabolism, but the effect of NPY receptor antagonists on metabolic-dysfunction-associated steatotic liver disease (MASLD), a common obesity-related comorbidity, are largely unknown. In this study, we report on the effects of antagonists of the NPY-2 receptor (Y2R) in comparison with empagliflozin and semaglutide, substances that are known to be beneficial in MASLD. (2) Methods: Diet-induced obese (DIO) male Wistar rats were randomized into the following treatment groups: empagliflozin, semaglutide ± PYY3-36, the Y2R antagonists JNJ 31020028 and a food-restricted group, as well as a control group. After a treatment period of 8 weeks, livers were weighed and histologically evaluated. QrtPCR was performed to investigate liver inflammation and de novo lipogenesis (in liver and adipose tissue). Serum samples were analysed for metabolic parameters. (3) Results: Semaglutide + PYY3-36 led to significant weight loss, reduced liver steatosis (p = 0.05), and decreased inflammation, insulin resistance, and leptin levels. JNJ-31020028 prevented steatosis (p = 0.03) without significant weight loss. Hepatic downregulation of de novo lipogenesis-regulating genes (SREBP1 and MLXIPL) was observed in JNJ-31020028-treated rats (p ≤ 0.0001). Food restriction also resulted in significantly reduced weight, steatosis, and hepatic de novo lipogenesis. (4) Conclusions: Body weight reduction (e.g., by food restriction or drugs like semaglutide ± PYY3-36) is effective in improving liver steatosis in DIO rats. Remarkably, the body-weight-neutral Y2R antagonists may be effective in preventing liver steatosis through a reduction in de novo lipogenesis, making this drug class a candidate for the treatment of (early) MASLD.