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Bile Acids as Regulatory Signalling Molecules

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Mammalian Sterols

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Abstract

Bile acids (BAs) are a large family of molecules that have a steroidal structure and are synthesized from cholesterol in the liver. BAs are physiological detergents important for the emulsification of dietary fats, drugs, and lipid-soluble vitamins in the intestine, and their subsequent absorption and transport to the liver for metabolism is followed by distribution to other tissues and organs. BAs also act as signalling molecules and are important for the regulation of their own synthesis, uptake and secretion as well as the control of cholesterol synthesis and the regulation of lipid and glucose metabolism. These processes are accomplished via the direct activation of the nuclear receptor farnesoid X receptor (FXR), TGR5, the pregnane X receptor (PXR) and the vitamin D receptor (VDR). In addition, other nuclear receptors, such as the constitutive androstane receptor (CAR) and the liver X receptor (LXR), can be indirectly influenced by BA, and these receptors, in turn, influence BA synthesis via feedback mechanisms and have a considerable influence on the metabolic processes of the entire organism. This chapter will focus on BA homeostasis, which is affected by BA synthesis, metabolism and disposition in the liver and intestine. Furthermore, the roles of BAs as signalling molecules and therapeutic drugs to treat several diseases and metabolic imbalances will be discussed. Since there are cross-species differences in the synthesis and metabolism of BAs, the chapter will focus on humans and mice and will point out differences between these two species.

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Authors and Affiliations

  1. Faculty of Medicine, Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Leipzig University, Leipzig, Germany

    Madlen Matz-Soja

  2. Section of Hepatology, Clinic and Polyclinic for Gastroenterology, Hepatology, Infectiology, Pneumology, University Clinic Leipzig, Leipzig, Germany

    Madlen Matz-Soja

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  1. Madlen Matz-Soja
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  1. Center for Functional Genomics and Bio-Chips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia

    Damjana Rozman

  2. Rudolf Schönheimer Institute of Biochemistry, Department of General Biochemistry, University of Leipzig, Faculty of Medicine, Leipzig, Germany

    Rolf Gebhardt

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Matz-Soja, M. (2020). Bile Acids as Regulatory Signalling Molecules. In: Rozman, D., Gebhardt, R. (eds) Mammalian Sterols . Springer, Cham. https://doi.org/10.1007/978-3-030-39684-8_5

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