Sandro L. Matos

Metabolic dysfunction-associated steatohepatitis (MASH) is characterized by hepatic steatosis, inflammation, fibrosis, and metabolic dysfunction, with limited therapeutic options currently available. This study investigated whether pharmacological inhibition of Galectin-3 (Gal-3), a β-galactoside-binding lectin implicated in inflammation and fibrosis, using modified citrus pectin (MCP), attenuates established MASH in ApoE-deficient mice. Mice were assigned to four groups: standard chow (CTL), standard chow plus MCP (CTL + MCP), Western diet with fructose-enriched drinking water (WD), and WD plus MCP (WD + MCP). MCP (1% in drinking water) was administered during the final four weeks of the 11-week experimental protocol, after the establishment of metabolic dysfunction and hepatic steatosis. Compared with untreated WD mice, WD + MCP mice exhibited improved glucose tolerance, as evidenced by a 22.9% reduction in glucose area under the curve (p = 0.01), and enhanced hepatic insulin signaling, reflected by a 254.1% increase in insulin-stimulated AKT2 phosphorylation (p = 0.0002). MCP treatment also reduced hepatic lipid accumulation (39.8%, p = 0.0055) and hepatic triglyceride content (26.1%, p = 0.0003), accompanied by reductions in circulating triglyceride and cholesterol concentrations. Furthermore, WD + MCP mice exhibited reduced hepatic Gal-3 expression (25.8%, p = 0.0199), decreased F4/80 immunoreactivity (49.2%, p = 0.0061), attenuated JNK phosphorylation (46.6%, p = 0.0118), reduced collagen deposition (47.0%, p = 0.0002), and lower plasma ALT (52.9%, p = 0.0009) and AST (48.8%, p = 0.04) activities. Collectively, these findings demonstrate that MCP attenuates multiple metabolic, inflammatory, fibrotic, and hepatic injury features of established Western diet-induced MASH, supporting Gal-3 as a promising therapeutic target and MCP as a potential pharmacological strategy for MASH.

The prevalence of non-alcoholic fatty liver disease (NAFLD) and its severe form, non-alcoholic steatohepatitis (NASH), is higher in men than in women of reproductive age, and postmenopausal women are especially susceptible to developing the disease. Aim: we evaluated if female apolipoprotein E (ApoE) KO mice were protected against Western-diet (WD)-induced NASH. Methods: Female ovariectomized (OVX) ApoE KO mice or sham-operated (SHAM) mice were fed either a WD or a regular chow (RC) for 7 weeks. Additionally, OVX mice fed a WD were treated with either estradiol (OVX + E2) or vehicle (OVX). Results: Whole-body fat, plasma glucose, and plasma insulin were increased and associated with increased glucose intolerance in OVX mice fed a WD (OVX + WD). Plasma and hepatic triglycerides, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) hepatic enzymes were also increased in the plasma of OVX + WD group, which was associated with hepatic fibrosis and inflammation. Estradiol replacement in OVX mice reduced body weight, body fat, glycemia, and plasma insulin associated with reduced glucose intolerance. Treatment also reduced hepatic triglycerides, ALT, AST, hepatic fibrosis, and inflammation in OVX mice. Conclusions: These data support the hypothesis that estradiol protects OVX ApoE KO mice from NASH and glucose intolerance.

One of the consequences of the Western lifestyle and high-fat diet is non-alcoholic fatty liver disease (NAFLD) and its aggressive form, non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis and hepatocellular carcinoma (HCC) and is rapidly becoming the leading cause of end-stage liver disease or liver transplantation. Currently, rodent NASH models lack significant aspects of the full NASH spectrum, representing a major problem for NASH research. Therefore, this work aimed to characterize a fast rodent model with all characteristic features of NASH. Eight-week-old male ApoE KO mice were fed with Western diet (WD), high fatty diet (HFD) or normal chow (Chow) for 7 weeks. Whole-body fat was increased by ~2 times in WD mice and HFD mice and was associated with increased glucose intolerance, hepatic triglycerides, and plasma ALT and plasma AST compared with Chow mice. WD mice also showed increased galectin-3 expression compared with Chow or HFD mice and increased plasma cholesterol compared with Chow mice. WD and HFD displayed increased hepatic fibrosis and increased F4/80 expression. WD mice also displayed increased levels of plasma MCP-1. Hepatic inflammatory markers were evaluated, and WD mice showed increased levels of TNF-α, MCP-1, IL-6 and IFN-γ. Taken together, these data demonstrated that the ApoE KO mouse fed with WD is a great model for NASH research, once it presents the fundamental parameters of the disease, including hepatic steatosis, fibrosis, inflammation, and metabolic syndrome.