A mutation in LXRα uncovers a role for cholesterol sensing in limiting metabolic dysfunction-associated steatohepatitis

Chitosan-Based Nanoparticles Targeted Delivery System: In Treatment Approach for Dyslipidemia

Hyperlipidemia, characterized by abnormally high lipid levels in the bloodstream, is a significant risk factor for cardiovascular diseases. Conventional treatments have limitations in efficacy and may lead to side effects. Nanotechnology offers unique advantages in drug delivery, including improved drug stability, prolonged circulation time, and enhanced tissue targeting. Using nanoparticles as carriers, therapeutic agents can be precisely delivered to the target site, such as the liver or arterial walls, where lipid metabolism occurs. Chitosan nanoparticles represent an advanced approach engineered with precision to target atherosclerotic plaques. They have dual functionalities, serving therapeutic and diagnostic purposes in managing atherosclerosis. Targeting strategies involve coating nanoparticles with ligands or antibodies that recognize specific receptors overexpressed in hyperlipidemic conditions. This selective uptake maximizes the therapeutic effect while minimizing off-target effects, making it a promising alternative to traditional treatments. The review provides an overview of recent research developments for managing dyslipidemia based on the molecular target pathway of dyslipidemia, focusing on Chitosan-based delivery systems that allow controlled drug release, targeting, and enhancing patient compliance.

Higher Residual and Metabolic Dysfunction-Associated Fatty Liver Disease Risk of the R-Enantiomer of Famoxadone in Mice

Famoxadone (FAM) is a widely used chiral fungicide that may contribute to metabolic dysfunction-associated fatty liver disease (MAFLD). However, the enantioselective toxicity and mechanism of action of famoxadone enantiomers remain unclear. The enantioselective bioaccumulation of famoxadone in mice was investigated, and the hepatotoxicity of famoxadone enantiomers, specifically in relation to MAFLD, was evaluated by a 12 week oral exposure to Rac-FAM, R-FAM, and S-FAM. R-FAM showed higher bioaccumulation than S-FAM, in which the concentrations of R-FAM were 3.52 and 242.69 times that of S-FAM in the liver at the no observed effect level (NOEL) and 1/10 NOEL, respectively. R-FAM was found to cause an increase in liver coefficients, a decrease in the AST/ALT ratio, enhanced expression of inflammation-related genes, and lipid droplet accumulation in the liver. In contrast, mice treated with S-FAM exhibited no significant changes in the quality of these indicators. These results suggest that R-famoxadone is more likely to be the dominant enantiomer affecting the liver. Furthermore, the important functional genes involved in glucose and lipid metabolism were detected. It was found that R-FAM significantly disrupted key lipid metabolic pathways in the liver, including glucose metabolism, fatty acid synthesis, triglyceride synthesis, and fatty acid β-oxidation. Additionally, R-FAM induced more severe disruptions in liver glucose and lipid metabolism compared to S-FAM. These research findings provide insights into the enantioselective toxicity of famoxadone enantiomers in terms of their role in promoting MAFLD development, contributing to the safe utilization of the chiral pesticide famoxadone.

Exploring the Roles of Liver X Receptors in Lipid Metabolism and Immunity in Atherosclerosis

Hypercholesterolemia causes atherosclerosis by inducing immune cell migration and chronic inflammation in arterial walls. Recent single-cell analyses reveal the presence of lipid-enriched foamy macrophages, as well as other macrophage subtypes, neutrophils, T cells, and B cells, in atherosclerotic plaques in both animal models and humans. These cells interact with each other and other cells, including non-immune cells such as endothelial cells and smooth muscle cells. They thereby regulate metabolic, inflammatory, phagocytic, and cell death processes, thus affecting the progression and stability of atherosclerotic plaques. The nuclear receptors liver X receptor (LXR)α and LXRβ are transcription factors that are activated by oxysterols and regulate lipid metabolism and immune responses. LXRs regulate cholesterol homeostasis by controlling cholesterol's transport, absorption, synthesis, and breakdown in the liver and intestine. LXRs are also highly expressed in tissue-resident and monocyte-derived macrophages and other immune cells, including both myeloid cells and lymphocytes, and they regulate both innate and adaptive immune responses. Interestingly, LXRs have immunosuppressive and immunoregulatory functions that are cell-type-dependent. In animal models of atherosclerosis, LXRs have been shown to be involved in both progression and regression phases. The pharmacological activation of LXR enhances cholesterol efflux from macrophages and promotes atherosclerosis progression. Deleting LXR in immune cells, especially myeloid cells, accelerates atherosclerosis by increasing monocyte migration, macrophage proliferation and activation, and neutrophil extracellular traps (NETs); furthermore, the deletion of hematopoietic LXRs impairs the regression of atherosclerotic plaques. Therefore, LXRs in immune cells may be a potent therapeutic target for atherosclerosis.