Molecular regulation mechanism of Farnesyl X receptor in bile acid and cholesterol metabolism in hyperlipidemic rats

Abstract

The study was aimed to elucidate the molecular mechanism of Farnesyl X receptor (FXR), Bile salt export pump (BSEP) and sodium-taurocholate cotransporting polypeptide (NTCP) in the metabolism of bile acid and cholesterol in hyperlipoidemia rats. Fifty male Wistar rats weighing 140.6±9.5g were randomly divided into two groups: the control group was given normal diet while the experimental group was given high-fat diet. Body weight was measured on a regular basis and liver weight was measured after sacrifice. Plasma glucose and lipids (total cholesterol, triglycerides, high density lipoprotein, low density lipoprotein) were determined by commercially available kits. Hepatic FXR, BSEP and NTCP gene expression and protein distribution were determined by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and immunohistochemistry. The results showed that the expression of FXR and BSEP mRNA in the experimental group was higher than that in the control group (P < 0.05). The expression of NTCP mRNA in the control group was higher than that in the experimental group (P < 0.05). Immuno-histological results showed that the positive rates of FXR, BSEP and NTCP expression in the experimental group were significantly different from those in the control group (P < 0.05). In conclusion, FXR and Bsep and Ntcp gene changes played an important protective role in lipid metabolism, especially for the rats with high-fat diet.