The role of intestine in metabolic dysregulation in murine Wilson disease

Background and aims Major clinical manifestations of Wilson disease (WD) are related to copper accumulation in the liver and the brain, and little is known about other tissues involvement in metabolic changes in WD. In vitro studies suggested that the loss of intestinal ATP7B could contribute to metabolic dysregulation in WD. We tested this hypothesis by evaluating gut microbiota and lipidome in two mouse models of WD and by characterizing a new mouse model with a targeted deletion of Atp7b in intestine. Methods Cecal content 16S sequencing and untargeted hepatic and plasma lipidome analyses in the Jackson Laboratory toxic-milk and the Atp7b null global knockout mouse models of WD were profiled and integrated. Intestine-specific Atp7b knockout mice ( Atp7b ΔIEC) was generated using B6.Cg-Tg(Vil1-cre)997Gum/J mice and Atp7b Lox/Lox mice, and characterized using targeted lipidome analysis following a high-fat diet challenge. Results Gut microbiota diversity was reduced in animal models of WD. Comparative prediction analysis revealed amino acid, carbohydrate, and lipid metabolism functions to be dysregulated in the WD gut microbial metagenome. Liver and plasma lipidomic profiles showed dysregulated tri- and diglyceride, phospholipid, and sphingolipid metabolism in WD models. When challenged with a high-fat diet, Atp7bΔIEC mice exhibited profound alterations to fatty acid desaturation and sphingolipid metabolism pathways as well as altered APOB48 distribution in intestinal epithelial cells. Conclusion Coordinated changes of gut microbiome and lipidome analyses underlie systemic metabolic manifestations in murine WD. Intestine-specific ATP7B deficiency affected both intestinal and systemic response to a high-fat challenge. WD is a systemic disease in which intestinal-specific ATP7B loss and diet influence phenotypic presentations. ### Competing Interest Statement The authors have declared no competing interest. * Atp7b’-’ : ( Atp7b null global knockout mouse on a hybrid background), Atp7bΔIEC : (intestine-specific Atp7b knockout mouse), C3H : (The Jackson Laboratory C3HeB/FeJ), DGs : (diglycerides), FXR : (farnesoid X receptor), LXR : (liver X receptors), HFD : (high fat diet), IEC : (intestinal epithelial cell), iWT : (Lox+/+/Cre-; littermate control for Atp7bΔIEC mice), KO : ( Atp7b null global knockout mouse on a C57Bl/6 background), LPCs : (lysophosphatidylcholines), PCs : (phosphatidylcholines), PCA : (principal component analysis), PE : (phosphatidylethanolamine), (PPAR) : peroxisome-proliferator-activated receptor, PLs : (phospholipids), SCD1 : (stearoyl-coenzyme A desaturase 1), SMs : (sphingomyelins), SREBP1c : (sterol regulatory element-binding protein), TAGs : (triacylglycerides), TGs : (triglycerides), tx-j : (The Jackson Laboratory toxic-milk mouse), VLCFA : (very-long-chain fatty acid), WD : (Wilson disease), WT : ( Atp7b+/+ littermate control for KO mice).