glycoursodeoxycholic-acid and Atherosclerosis

Background Although glycoursodeoxycholic acid (GUDCA) has been associated with the improvement of metabolic disorders, its effect on atherosclerosis remains elusive. This study aimed to investigate the role of GUDCA in the development of atherosclerosis and its potential mechanisms. Methods and Results Human THP-1 macrophages were used to investigate the effect of GUDCA on oxidized low-density lipoprotein-induced foam cell formation in vitro. We found that GUDCA downregulated scavenger receptor A1 mRNA expression, reduced oxidized low-density lipoprotein uptake, and inhibited macrophage foam cell formation. In an in vivo study, apolipoprotein E-deficient mice were fed a Western diet for 10 weeks to induce atherosclerosis, and then were gavaged once daily with or without GUDCA for 18 weeks. Parameters of systemic metabolism and atherosclerosis were detected. We found that GUDCA improved cholesterol homeostasis and protected against atherosclerosis progression as evidenced by reduced plaque area along with lipid deposition, ameliorated local chronic inflammation, and elevated plaque stability. In addition, 16S rDNA sequencing showed that GUDCA administration partially normalized the Western diet-associated gut microbiota dysbiosis. Interestingly, the changes of bacterial genera (

Topics: Animals; Apolipoproteins E; Atherosclerosis; Cells, Cultured; Disease Models, Animal; Disease Progression; Down-Regulation; Female; Foam Cells; Gastrointestinal Microbiome; Gene Expression Regulation; Humans; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; RNA, Messenger; Scavenger Receptors, Class A; Ursodeoxycholic Acid

Intestinal farnesoid X receptor (FXR) signaling is involved in the development of obesity, fatty liver disease, and type 2 diabetes. However, the role of intestinal FXR in atherosclerosis and its potential as a target for clinical treatment have not been explored. The serum levels of fibroblast growth factor 19 (FGF19), which is encoded by an FXR target gene, were much higher in patients with hypercholesterolemia than in control subjects and were positively related to circulating ceramide levels, indicating a link between intestinal FXR, ceramide metabolism, and atherosclerosis. Among ApoE-/- mice fed a high-cholesterol diet (HCD), intestinal FXR deficiency (in FxrΔIE ApoE-/- mice) or direct FXR inhibition (via treatment with the FXR antagonist glycoursodeoxycholic acid [GUDCA]) decreased atherosclerosis and reduced the levels of circulating ceramides and cholesterol. Sphingomyelin phosphodiesterase 3 (SMPD3), which is involved in ceramide synthesis in the intestine, was identified as an FXR target gene. SMPD3 overexpression or C16:0 ceramide supplementation eliminated the improvements in atherosclerosis in FxrΔIE ApoE-/- mice. Administration of GUDCA or GW4869, an SMPD3 inhibitor, elicited therapeutic effects on established atherosclerosis in ApoE-/- mice by decreasing circulating ceramide levels. This study identified an intestinal FXR/SMPD3 axis that is a potential target for atherosclerosis therapy.

Topics: Animals; Atherosclerosis; Ceramides; Diet, High-Fat; Female; Humans; Intestinal Mucosa; Male; Mice; Mice, Knockout, ApoE; Receptors, Cytoplasmic and Nuclear; Sphingomyelin Phosphodiesterase; Ursodeoxycholic Acid