Transcriptomics and metabolomics analysis of the pathogenesis of a novel hyperlipidemia-susceptible rat strain

To investigate the pathogenesis of hyperlipidemia in Wistar-SD Hypercholesterolemia (WSHc) rats and clarify the genetic and biological characteristics. Six 7-8-week-old WSHc rats were fed a high-fat diet (HFD), and another six were fed ordinary feed, with age-matched Wistar rats as the control group under the same treatment. After 16 weeks, serum lipid levels were measured. A transcriptomic analysis of the differences in gene expression of the liver related to cholesterol metabolism was conducted, and 119 differentially expressed genes were discovered through bioinformatics analysis and molecular biology verification. UHPLC-Q-TOF/MS was applied for lipidomic analysis of serum samples from each group. WSHc rats developed dyslipidemia after a high-fat diet was induced. Investigation of the gene profiles using the protein-protein interaction network and one-cluster clustering analysis identified SREBF1 as a HUB gene and NR1d1 as an independent key gene. SREBF1 and NR1d1 were further validated in molecular biology experiments, which was consistent with the transcriptomic results. Lipid metabolomics analysis identified seven lipid subclasses and 84 lipid molecules. The metabolic profiles of serum lipid media of the WSHc + HFD and WSHc + SC groups were significantly different compared to that of the control group by 62 and 70 lipid molecules, respectively. Differential metabolites were produced via sphingolipid and glycerophospholipid metabolism. A stable model of hypercholesterolemia in WSHc rats can be generated by feeding on a high-fat diet, and the pathogenesis mainly involves two key genes, SREBF1 and NR1d1, and the sphingolipid and glycerophospholipid metabolism pathways.