Résumé
The synthesis of cholesterol and fatty acids (FA) in the liver is independently regulated by SREBP-2 and SREBP-1c, respectively. Here, we genetically deleted Srebf-2 from hepatocytes and confirmed that SREBP-2 regulates all genes involved in cholesterol biosynthesis, the LDL receptor, and PCSK9; a secreted protein that degrades LDL receptors in the liver. Surprisingly, we found that elimination of Srebf-2 in hepatocytes of mice also markedly reduced SREBP-1c and the expression of all genes involved in FA and triglyceride synthesis that are normally regulated by SREBP-1c. The nuclear receptor LXR is necessary for Srebf-1c transcription. The deletion of Srebf-2 and subsequent lower sterol synthesis in hepatocytes eliminated the production of an endogenous sterol ligand required for LXR activity and SREBP-1c expression. These studies demonstrate that cholesterol and FA synthesis in hepatocytes are coupled and that flux through the cholesterol biosynthetic pathway is required for the maximal SREBP-1c expression and high rates of FA synthesis.
Langue d'origine | English |
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Numéro d'article | e25015 |
Journal | eLife |
Volume | 6 |
DOI | |
Statut de publication | Published - févr. 28 2017 |
Publié à l'externe | Oui |
Note bibliographique
Funding Information:We thank Tuyet Dang, Bonne Thompson, Marcus Thornton, and Judy Sanchez, for excellent technical assistance and Jian Yang for assistance in the production of the L-Srebf-2-/- mice. We also thank Drs. Joseph L Goldstein and Michael S Brown for helpful suggestions throughout the project. This work was supported by grants from the National Institutes of Health HL-20948.
Publisher Copyright:
© Rong et al.
ASJC Scopus Subject Areas
- General Neuroscience
- General Immunology and Microbiology
- General Biochemistry,Genetics and Molecular Biology