Bile Acid-Activated Receptors: A Review on FXR and Other Nuclear Receptors

Dong-Ju Shin1, Li Wang2,3

  • 1Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA. dong-ju.shin@uconn.edu.

Insights

Nuclear receptors (NRs) regulate bile acid homeostasis and metabolism. These signaling pathways are integral to lipid, glucose, and energy balance.

Area of Science:

  • Endocrinology
  • Molecular Biology
  • Metabolic Research

Background:

  • Nuclear receptors (NRs) are crucial ligand-dependent transcription factors governing biological processes.
  • Bile acids, synthesized in the liver, act as signaling molecules regulating metabolism, detoxification, and regeneration.
  • NRs and bile acids form an intricate signaling network impacting various physiological functions.

Purpose of the Study:

  • To review the role of nuclear receptors in maintaining bile acid homeostasis.
  • To highlight the regulatory functions of NRs in bile acid, lipid, and glucose metabolism.
  • To elucidate the interplay between bile acid signaling and nuclear receptor activity.

Main Methods:

  • Literature review focusing on nuclear receptors and bile acid signaling.
  • Analysis of the regulatory roles of specific NRs (FXR, PXR, CAR, VDR, SHP) in bile acid metabolism.
  • Examination of NR involvement in lipid and glucose metabolic pathways.

Main Results:

  • Nuclear receptors are integral to bile acid signaling and homeostasis.
  • Specific NRs like FXR, PXR, CAR, and VDR play key roles in regulating bile acid metabolism.
  • NRs significantly influence lipid and glucose metabolism through bile acid signaling pathways.

Conclusions:

  • Nuclear receptors are essential regulators of bile acid homeostasis.
  • The interplay between bile acids and NRs is critical for metabolic regulation.
  • Understanding these pathways offers insights into metabolic disorders and therapeutic strategies.

Related Concept Videos

Transducer Mechanism: Nuclear Receptors01:31

Transducer Mechanism: Nuclear Receptors

Nuclear receptors, or NRs, are unique transcription factors that regulate gene transcription and affect the cellular pathways involved in reproduction, development, or metabolism. Their ability to be stimulated by small lipophilic ligands and control vital cellular processes makes them ideal drug targets. Nearly 10-15% of currently prescribed drugs target these receptors.
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
2.4K
Internal Receptors01:31

Internal Receptors

Many cellular signals are hydrophilic and therefore cannot pass through the plasma membrane. However, small or hydrophobic signaling molecules can cross the hydrophobic core of the plasma membrane and bind to internal, or intracellular, receptors that reside within the cell. Many mammalian steroid hormones use this mechanism of cell signaling, as does nitric oxide (NO) gas.
74.3K
Receptor-mediated Endocytosis01:39

Receptor-mediated Endocytosis

Overview
110.6K
Enzyme-linked Receptors01:00

Enzyme-linked Receptors

Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of receptors that include the receptor tyrosine kinase (RTK) family. Many growth factors and hormones bind to and activate the RTKs.
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
86.2K
G-protein Coupled Receptors01:21

G-protein Coupled Receptors

G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
131.7K
Types of Receptors: Internal Receptors01:07

Types of Receptors: Internal Receptors

Many cellular signals are hydrophilic and cannot pass through the plasma membrane. However, small or hydrophobic signaling molecules can cross the hydrophobic core of the plasma membrane and bind intracellular receptors that reside within the cell cytoplasm or nucleus. Many mammalian steroid hormones and nitric oxide (NO) gas use this cell signaling mechanism.
Similar to membrane-bound receptors, the binding of a ligand to the intracellular receptor of causes a conformational change in the...
31.6K