Redundant Pathways for Negative Feedback Regulation of Bile Acid Production

• Published in: Developmental cell Vol. 2; no. 6; pp. 721 - 731
• Main Authors: Wang, Li, Lee, Yoon-Kwang, Bundman, Donnie, Han, Yunqing, Thevananther, Sundararajah, Kim, Chang-Soo, Chua, Steven S, Wei, Ping, Heyman, Richard A, Karin, Michael, Moore, David D
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2002
• Subjects: Animals; Anticholesteremic Agents - pharmacology; Bile Acids and Salts - biosynthesis; Bile Acids and Salts - metabolism; Cholesterol 7-alpha-Hydroxylase - metabolism; Cholic Acid - administration & dosage; DNA-Binding Proteins - metabolism; Feedback - physiology; Homeostasis; Isoxazoles - pharmacology; JNK Mitogen-Activated Protein Kinases; Mice; Mice, Knockout; Mitogen-Activated Protein Kinases - metabolism; Nicotinic Acids - pharmacology; Nuclear Proteins - drug effects; Nuclear Proteins - metabolism; Pregnane X Receptor; Receptors, Cytoplasmic and Nuclear - deficiency; Receptors, Cytoplasmic and Nuclear - genetics; Receptors, Cytoplasmic and Nuclear - metabolism; Receptors, Retinoic Acid - agonists; Receptors, Retinoic Acid - metabolism; Receptors, Steroid - metabolism; Retinoid X Receptors; RNA, Messenger - analysis; Stem Cells - physiology; Tetrahydronaphthalenes - pharmacology; Transcription Factors - agonists; Transcription Factors - metabolism
• ISSN: 1534-5807; 1878-1551
• DOI: 10.1016/S1534-5807(02)00187-9

The orphan nuclear hormone receptor SHP has been proposed to have a key role in the negative feedback regulation of bile acid production. Consistent with this, mice lacking the SHP gene exhibit mild defects in bile acid homeostasis and fail to repress cholesterol 7-α-hydroxylase expression in response to a specific agonist for the bile acid receptor FXR. However, this repression is retained in SHP null mice fed bile acids, demonstrating the existence of compensatory repression pathways of bile acid signaling. We provide evidence for two such pathways, based on activation of the xenobiotic receptor PXR or the c-Jun N-terminal kinase JNK. We conclude that redundant mechanisms regulate this critical aspect of cholesterol homeostasis.