Therapeutic Mechanisms and Clinical Effects of Glucagon-like Peptide 1 Receptor Agonists in Nonalcoholic Fatty Liver Disease

Reduction of Hepatic Fat Content by Dulaglutide for the Treatment of Diabetes Mellitus: A Two-Centre Open, Single-Arm Trial

BACKGROUND

With the elevated level of NAFLD prevalence, the incidence of diabetes, hypertension, metabolic syndrome and other diseases is also significantly elevated. GLP-1RA can exert weight loss, glucose-lowering effects and various nonglycaemic effects. However, the relationship between quantitative reduction in hepatic fat content and improvement of pancreatic islet function by GLP-1RA is unclear.

METHODS

This trial was a single-arm open cohort study. A total of 38 patients with T2DM and NAFLD were enrolled in the GLP-1RA treatment group. The included patients were tested for biochemical and blood glucose levels, adiponectin and FGF21 levels, and liver fat content was measured using MRI. Measure the above indicators again after at least 3 months of GLP-1RA treatment. Divided into Q1 (average decrease of 0.37%) and Q2 (average decrease of 8.6%) groups based on the degree of reduction in liver fat content.

RESULTS

Q2 group showed an average reduction in liver fat content of 8.6%, a decrease in glycated haemoglobin of 18.17%, a weight loss of 7.29% and an increase in fasting c-peptide release by 1.03%, 1-h and 2-h postprandial c-peptide release by 28.86% and 18.28% respectively. In contrast, Q1 group had an average reduction in liver fat content of 0.37%, a decrease in glycated haemoglobin of only 6.53%, a weight loss of 3.41%, a decrease in fasting c-peptide release by 1.91% and an increase in 1-h and 2-h postprandial c-peptide release by 19.18% and 11.66% respectively.

CONCLUSION

Reduction in liver fat content effectively improves pancreatic islet function secretion, particularly postprandial c-peptide secretion, especially in the first hour after a meal. This improvement leads to a decrease in glycated haemoglobin levels and promotes better compliance with blood glucose control.

Approved and Emerging Hormone-Based Anti-Obesity Medications: A Review Article

Obesity is a heterogeneous, complex, and chronic disease that has a detrimental impact on disability-adjusted life years across the globe. Recent advancements in our understanding of gut-brain communication at the molecular level have driven the development of next-generation anti-obesity medications (AOMs). Glucagon-like peptide-1 receptor agonists (GLP1RAs) remain the front-runners in this rapidly evolving landscape of hormone-based AOMs. Two GLP1RAs, namely Liraglutide and Semaglutide, have been approved by the Food and Drug Administration (FDA) and European Medicine Agency (EMA) for use in clinical practice for weight loss. Three oral GLP1RAs, namely Semaglutide, Danuglipron, and Orforglipron, are undergoing advanced clinical trials in individuals with obesity. Amylin receptor agonist (AMYRA) Cagrilintide, when used alone or in combination with Semaglutide, has demonstrated substantial weight reduction in clinical trials. Tirzepatide, a dual agonist for the glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 receptors, has been observed to be associated with a significant placebo-subtracted weight reduction of 17.8% in a 72-week randomized controlled trial. Novel approaches targeting glucagon signalling have also yielded promising preliminary results. Three long-acting GLP1R/glucagon receptor (GCGR) dual agonists, namely Survodutide, Mazdutide, and Pemvidutide, exhibited significant weight loss in clinical trials. Retatrutide, a GLP1R/GCGR/GIPR tri-agonist, has been associated with a placebo-subtracted weight reduction of -22.1% in a 48-week phase-II trial. As a note of caution, long-term data on such medications' safety and cardiovascular benefits is yet to be ascertained. Our review provides a comprehensive overview of the approved and emerging hormone-based AOMs, highlighting the diversity of options that might become available in the near future.

Roflumilast ameliorates GAN diet-induced non-alcoholic fatty liver disease by reducing hepatic steatosis and fibrosis in ob/ob mice

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent progressive liver disease. Currently, there is only one drug for NAFLD treatment, and the options are limited. Phosphodiesterase-4 (PDE-4) inhibitors have potential in treating NAFLD. Therefore, this study aims to investigate the effect of roflumilast on NAFLD. Here, we fed ob/ob mice to induce the NAFLD model by GAN diet. Roflumilast (1 mg/kg) was administered orally once daily. Semaglutide (20 nmol/kg), used as a positive control, was injected subcutaneously once daily. Our findings showed that roflumilast has beneficial effects on NAFLD. Roflumilast prevented body weight gain and improved lipid metabolism in ob/ob-GAN NAFLD mice. In addition, roflumilast decreased hepatic steatosis by down-regulating the expression of hepatic fatty acid synthesis genes (SREBP1c, FASN, and CD36) and improving oxidative stress. Roflumilast not only reduced liver injury by decreasing serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, but also ameliorated hepatic inflammation by reducing the gene expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6). Roflumilast lessened liver fibrosis by inhibiting the expression of fibrosis mRNA (TGFβ1, α-SMA, COL1a1, and TIMP-1). Collectively, roflumilast could ameliorate NAFLD, especially in reducing hepatic steatosis and fibrosis. Our findings suggested a PDE-4 inhibitor roflumilast could be a potential drug for NAFLD.

Therapeutic Effects of Semaglutide on Nonalcoholic Fatty Liver Disease with Type 2 Diabetes Mellitus and Obesity: An Open-Label Controlled Trial

BACKGROUND

GLP-1 receptor agonists (GLP-1 RAs) have been shown to improve glycemic control and insulin sensitivity and reduce body weight in obese patients with type 2 diabetes mellitus (T2D). This trial sought to evaluate the therapeutic effect of oral and subcutaneous semaglutide in NAFLD and its sequelae in obesity and/or T2D.

METHODS

In an open-labelled intervention study, the sample was 180 patients classified into three parallel groups (1:1:1): group I received oral semaglutide, group II patients received injectable semaglutide, and group III received pioglitazone and/or vitamin E. Patients were evaluated at 6 and 12 months.

RESULTS

There was a substantial improvement in lipid profile, liver enzymes, and body mass index, especially in group II. As for HDL, only group II showed a consistent increase at both 6 months (51 ± 4.62 mg/dL) and 12 months (50.08 ± 2.45 mg/dL) compared with baseline (45.6 ± 6.37 mg/dL) (p-value < 0.001). Despite the non-significant difference in NAFLD fibrosis score (NFS) (p-value = 0.45 and 0.63), group II had significantly lower scores of the fibrosis-4 score (FIB-4), liver stiffness measurement (LSM), and controlled attenuation parameter (CAP) at 6 and 12 months (p-value < 0.001). Conclusions: Semaglutide improves lipid profile, liver steatosis, and fibrosis parameters and reduces the BMI in T2D and obese patients with NAFLD.

Semaglutide Concurrently Improves Vascular and Liver Indices in Patients With Type 2 Diabetes and Fatty Liver Disease

Context

The cardiovascular benefits of semaglutide are established; however, its effects on surrogate vascular markers and liver function are not known.

Objective

To investigate the effects of semaglutide on vascular, endothelial, and liver function in patients with type 2 diabetes (T2DM) and nonalcoholic fatty liver disease (NAFLD).

Methods

Overall, 75 consecutive subjects with T2DM and NAFLD were enrolled: 50 patients received semaglutide 1 mg (treatment group) and 25 patients received dipeptidyl peptidase 4 inhibitors (control group). All patients underwent a clinical, vascular, and hepatic examination with Fibroscan elastography at 4 and 12 months after inclusion in the study.

Results

Treatment with semaglutide resulted in a reduction of Controlled Attenuation Parameter (CAP) score, E fibrosis score, NAFLD fibrosis score, Fibrosis-4 (FIB-4) score and perfused boundary region (PBR) at 4 and at 12 months (P < .05), contrary to controls. Patients treated with semaglutide showed a greater decrease of central systolic blood pressure (SBP) (-6% vs -4%, P = .048 and -11% vs -9%, P = .039), augmentation index (AIx) (-59% vs -52%, P = .041 and -70% vs -57%, P = .022), and pulse wave velocity (PWV) (-6% vs -3.5%, P = .019 and -12% vs -10%, P = .036) at 4 and at 12 months, respectively. In all patients, ΔPWV and ΔPBR were correlated with a corresponding reduction of CAP, E fibrosis, NAFLD fibrosis, and FIB-4 scores.

Conclusion

Twelve-month treatment with semaglutide simultaneously improves arterial stiffness, endothelial function, and liver steatosis and fibrosis in patients with T2DM and NAFLD.

Crosstalk between Epigenetics and Metabolic Reprogramming in Metabolic Dysfunction-Associated Steatotic Liver Disease-Induced Hepatocellular Carcinoma: A New Sight

Epigenetic and metabolic reprogramming alterations are two important features of tumors, and their reversible, spatial, and temporal regulation is a distinctive hallmark of carcinogenesis. Epigenetics, which focuses on gene regulatory mechanisms beyond the DNA sequence, is a new entry point for tumor therapy. Moreover, metabolic reprogramming drives hepatocellular carcinoma (HCC) initiation and progression, highlighting the significance of metabolism in this disease. Exploring the inter-regulatory relationship between tumor metabolic reprogramming and epigenetic modification has become one of the hot directions in current tumor metabolism research. As viral etiologies have given way to metabolic dysfunction-associated steatotic liver disease (MASLD)-induced HCC, it is urgent that complex molecular pathways linking them and hepatocarcinogenesis be explored. However, how aberrant crosstalk between epigenetic modifications and metabolic reprogramming affects MASLD-induced HCC lacks comprehensive understanding. A better understanding of their linkages is necessary and urgent to improve HCC treatment strategies. For this reason, this review examines the interwoven landscape of molecular carcinogenesis in the context of MASLD-induced HCC, focusing on mechanisms regulating aberrant epigenetic alterations and metabolic reprogramming in the development of MASLD-induced HCC and interactions between them while also updating the current advances in metabolism and epigenetic modification-based therapeutic drugs in HCC.

Bacteroides and NAFLD: pathophysiology and therapy

Non-alcoholic fatty liver disease (NAFLD) is a prevalent chronic liver condition observed globally, with the potential to progress to non-alcoholic steatohepatitis (NASH), cirrhosis, and even hepatocellular carcinoma. Currently, the US Food and Drug Administration (FDA) has not approved any drugs for the treatment of NAFLD. NAFLD is characterized by histopathological abnormalities in the liver, such as lipid accumulation, steatosis, hepatic balloon degeneration, and inflammation. Dysbiosis of the gut microbiota and its metabolites significantly contribute to the initiation and advancement of NAFLD. Bacteroides, a potential probiotic, has shown strong potential in preventing the onset and progression of NAFLD. However, the precise mechanism by which Bacteroides treats NAFLD remains uncertain. In this review, we explore the current understanding of the role of Bacteroides and its metabolites in the treatment of NAFLD, focusing on their ability to reduce liver inflammation, mitigate hepatic steatosis, and enhance intestinal barrier function. Additionally, we summarize how Bacteroides alleviates pathological changes by restoring the metabolism, improving insulin resistance, regulating cytokines, and promoting tight-junctions. A deeper comprehension of the mechanisms through which Bacteroides is involved in the pathogenesis of NAFLD should aid the development of innovative drugs targeting NAFLD.

Semaglutide Improves Liver Steatosis and De Novo Lipogenesis Markers in Obese and Type-2-Diabetic Mice with Metabolic-Dysfunction-Associated Steatotic Liver Disease

Metabolic-dysfunction-associated steatotic liver disease (MASLD) is a prevalent clinical condition associated with elevated morbidity and mortality rates. Patients with MASLD treated with semaglutide, a glucagon-like peptide-1 receptor agonist, demonstrate improvement in terms of liver damage. However, the mechanisms underlaying this beneficial effect are not yet fully elucidated. We investigated the efficacy of semaglutide in halting MASLD progression using a genetic mouse model of diabesity. Leptin-receptor-deficient mice with obesity and diabetes (BKS db/db) were either untreated or administered with semaglutide for 11 weeks. Changes in food and water intake, body weight and glycemia were monitored throughout the study. Body fat composition was assessed by dual-energy X-ray absorptiometry. Upon sacrifice, serum biochemical parameters, liver morphology, lipidomic profile and liver-lipid-related pathways were evaluated. The semaglutide-treated mice exhibited lower levels of glycemia, body weight, serum markers of liver dysfunction and total and percentage of fat mass compared to untreated db/db mice without a significant reduction in food intake. Histologically, semaglutide reduced hepatic steatosis, hepatocellular ballooning and intrahepatic triglycerides. Furthermore, the treatment ameliorated the hepatic expression of de novo lipogenesis markers and modified lipid composition by increasing the amount of polyunsaturated fatty acids. The administration of semaglutide to leptin-receptor-deficient, hyperphagic and diabetic mice resulted in the amelioration of MASLD, likely independently of daily caloric intake, suggesting a direct effect of semaglutide on the liver through modulation of the lipid profile.

Evolving role of semaglutide in NAFLD: in combination, weekly and oral administration

Non alcoholic fatty disease (NAFLD) is the most common chronic liver disease that is managed in the liver departments. It seems that the prevalence of the disease is rising worldwide and as it has the same pathogenetic pathways with metabolic syndrome, treatments that target components of the metabolic syndrome seem promising for the therapy of NAFLD as well. In this review we discuss the evolving role of semaglutide, which is a glucagon-like peptide-1 receptor agonist (GLP-1 RA) that has been already approved for the treatment of type II diabetes mellitus (T2DM) and obesity.

Meeting at the Crossroad between Obesity and Hepatic Carcinogenesis: Unique Pathophysiological Pathways Raise Expectations for Innovative Therapeutic Approaches

The escalating global prevalence of obesity and its intricate association with the development of hepatocellular carcinoma (HCC) pose a substantial challenge to public health. Obesity, acknowledged as a pervasive epidemic, is linked to an array of chronic diseases, including HCC, catalyzing the need for a comprehensive understanding of its molecular underpinnings. Notably, HCC has emerged as a leading malignancy with rising incidence and mortality. The transition from viral etiologies to the prominence of metabolic dysfunction-associated fatty liver disease (MAFLD)-related HCC underscores the urgent need to explore the intricate molecular pathways linking obesity and hepatic carcinogenesis. This review delves into the interwoven landscape of molecular carcinogenesis in the context of obesity-driven HCC while also navigating using the current therapeutic strategies and future prospects for combating obesity-related HCC. We underscore the pivotal role of obesity as a risk factor and propose an integrated approach encompassing lifestyle interventions, pharmacotherapy, and the exploration of emerging targeted therapies. As the obesity-HCC nexus continues to challenge healthcare systems globally, a comprehensive understanding of the intricate molecular mechanisms and innovative therapeutic strategies is imperative to alleviate the rising burden of this dual menace.