Dietary choline prevents high fat-induced disorder of hepatic cholesterol metabolism through SREBP-2/HNF-4α/CYP7A1 pathway in a freshwater teleost yellow catfish Pelteobagrus fulvidraco

Lipid overload-induced hepatic cholesterol accumulation is a major public health problem worldwide, and choline has been reported to ameliorate cholesterol accumulation, but its mechanism remains unclear. Our study found that choline prevented high-fat diet (HFD)-induced cholesterol metabolism disorder and enhanced choline uptake and phosphatidylcholine synthesis in the liver tissues; choline incubation prevented fatty acid (FA) -induced cholesterol accumulation and FA-induced inhibition of bile acid synthesis. Moreover, compared to single FA incubation, choline incubation or FA + choline co-incubation increased the mRNA abundances and protein levels of HNF4 alpha and up-regulated the degradation of cholesterol into bile acids. Mechanistically, choline pre-vented the FA-induced accumulation of SREBP2 protein and the interaction between SREBP2 and HNF4 alpha, thereby enhancing the DNA binding capacity of the HNF4 alpha to the CYP7A1 promoter, and promoting the degradation of cholesterol into bile acids. Our study elucidated the novel regulatory mechanisms of choline preventing HFD-induced cholesterol accumulation and increasing bile acid synthesis by SREBP-2/HNF-4 alpha/ CYP7A1 pathway.

Automated summary

Choline can prevent high-fat diet-induced cholesterol accumulation and increase bile acid synthesis through the SREBP-2/HNF-4 alpha/CYP7A1 pathway.