Bile acid

Related publications (79)

Farnesoid X receptor inhibits glucagon-like peptide-1 production by enteroendocrine L cells

Alessia Perino, Kristina Schoonjans, Yasmine Sebti

Bile acids are signalling molecules, which activate the transmembrane receptor TGR5 and the nuclear receptor FXR. BA sequestrants (BAS) complex bile acids in the intestinal lumen and decrease intestinal FXR activity. The BAS-BA complex also induces glucagon-like peptide-1 (GLP-1) production by L cells which potentiates beta-cell glucose-induced insulin secretion. Whether FXR is expressed in L cells and controls GLP-1 production is unknown. Here, we show that FXR activation in L cells decreases proglucagon expression by interfering with the glucose-responsive factor Carbohydrate-Responsive Element Binding Protein (ChREBP) and GLP-1 secretion by inhibiting glycolysis. In vivo, FXR deficiency increases GLP-1 gene expression and secretion in response to glucose hence improving glucose metabolism. Moreover, treatment of ob/ob mice with the BAS colesevelam increases intestinal proglucagon gene expression and improves glycaemia in a FXR-dependent manner. These findings identify the FXR/GLP-1 pathway as a new mechanism of BA control of glucose metabolism and a pharmacological target for type 2 diabetes.

Nature Publishing Group2015

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Nuclear receptors play pleiotropic roles in cell differentiation, development, proliferation, and metabolic processes to govern liver physiology and pathology. The nuclear receptor, liver receptor homolog-1 (LRH-1, NR5A2), originally identified in the liver as a regulator of bile acid and cholesterol homeostasis, was recently recognized to coordinate a multitude of other hepatic metabolic processes, including glucose and lipid processing, methyl group sensing, and cellular stress responses. In this review, we summarize the physiological and pathophysiological functions of LRH-1 in the liver, as well as the molecular mechanisms underlying these processes. This review also focuses on the recent advances highlighting LRH-1 as an attractive target for liver-associated diseases, such as non-alcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC).

2021

Complementary use of sterols and bile acids as faecal biomarkers in archaelogical soils.

University of Bristol1997

Intestinal FXR agonism promotes adipose tissue browning and reduces obesity and insulin resistance

Alessia Perino, Kristina Schoonjans

The systemic expression of the bile acid (BA) sensor farnesoid X receptor (FXR) has led to promising new therapies targeting cholesterol metabolism, triglyceride production, hepatic steatosis and biliary cholestasis. In contrast to systemic therapy, bile acid release during a meal selectively activates intestinal FXR. By mimicking this tissue-selective effect, the gut-restricted FXR agonist fexaramine (Fex) robustly induces enteric fibroblast growth factor 15 (FGF15), leading to alterations in BA composition, but does so without activating FXR target genes in the liver. However, unlike systemic agonism, we find that Fex reduces diet-induced weight gain, body-wide inflammation and hepatic glucose production, while enhancing thermogenesis and browning of white adipose tissue (WAT). These pronounced metabolic improvements suggest tissue-restricted FXR activation as a new approach in the treatment of obesity and metabolic syndrome.

Nature Publishing Group2015

Another Shp on the Horizon for Bile Acids

Alessia Perino, Kristina Schoonjans

Bile acid metabolism is tightly controlled due to the toxic effects of bile acid overload. In this issue, research from the Feng lab reports Shp2 as a novel integrator of hepatic bile acid and FGF15/FGF19 signaling, adding another layer of complexity to the control of bile acid biosynthesis.

Cell Press2014

Bile acids deoxycholic acid and ursodeoxycholic acid differentially regulate human beta-defensin-1 and-2 secretion by colonic epithelial cells

Alessia Perino, Kristina Schoonjans

Bile acids and epithelial-derived human beta-defensins (H beta Ds) are known to be important factors in the regulation of colonic mucosal barrier function and inflammation. We hypothesized that bile acids regulate colonic H beta D expression and aimed to test this by investigating the effects of deoxycholic acid (DCA) and ursodeoxycholic acid on the expression and release of H beta D1 and H beta D2 from colonic epithelial cells and mucosal tissues. DCA (10-150 mu M) stimulated the release of both H beta D1 and H beta D2 from epithelial cell monolayers and human colonic mucosal tissue in vitro. In contrast, ursodeoxycholic acid (50-200 mu M) inhibited both basal and DCA-induced defensin release. Effects of DCA were mimicked by the Takeda GPCR 5 agonist, INT-777 (50 mu M), but not by the farnesoid X receptor agonist, GW4064 (10 mu M). INT-777 also stimulated colonic H beta D1 and H beta D2 release from wild-type, but not Takeda GPCR 5(-/-), mice. DCA stimulated phosphorylation of the p65 subunit of NF-kappa B, an effect that was attenuated by ursodeoxycholic acid, whereas an NF-kappa B inhibitor, BMS-345541 (25 mu M), inhibited DCA-induced H beta D2, but not H beta D1, release. We conclude that bile acids can differentially regulate colonic epithelial H beta D expression and secretion and discuss the implications of our findings for intestinal health and disease.

Federation of American Society of Experimental Biology2017

Short Article Hypothalamic bile acid-TGR5 signaling protects from obesity

Alessia Perino, Kristina Schoonjans

Bile acids (BAs) improve metabolism and exert anti-obesity effects through the activation of the Takeda G protein-coupled receptor 5 (TGR5) in peripheral tissues. TGR5 is also found in the brain hypothalamus, but whether hypothalamic BA signaling is implicated in body weight control and obesity pathophysiology remains unknown. Here we show that hypothalamic BA content is reduced in diet-induced obese mice. Central administration of BAs or a specific TGR5 agonist in these animals decreases body weight and fat mass by activating the sympathetic nervous system, thereby promoting negative energy balance. Conversely, genetic downregulation of hypothalamic TGR5 expression in the mediobasal hypothalamus favors the development of obesity and worsens established obesity by blunting sympathetic activity. Lastly, hypothalamic TGR5 signaling is required for the anti-obesity action of dietary BA supplementation. Together, these findings identify hypothalamic TGR5 signaling as a key mediator of a top-down neural mechanism that counteracts diet induced obesity.

CELL PRESS2021

The normal mechanisms of pregnancy-induced liver growth are not maintained in mice lacking the bile acid sensor Fxr

Chikage Mataki, Kristina Schoonjans

Milona A, Owen BM, van Mil S, Dormann D, Mataki C, Boudjelal M, Cairns W, Schoonjans K, Milligan S, Parker M, White R, Williamson C. The normal mechanisms of pregnancy-induced liver growth are not maintained in mice lacking the bile acid sensor Fxr. Am J Physiol Gastrointest Liver Physiol 298: G151-G158, 2010. First published October 8, 2009; doi:10.1152/ajpgi.00336.2009.-Rodents undergo gestational hepatomegaly to meet the increased metabolic demands on the maternal liver during pregnancy. This is an important physiological process, but the mechanisms and signals driving pregnancy-induced liver growth are not known. Here, we show that liver growth during pregnancy precedes maternal body weight gain, is proportional to fetal number, and is a result of hepatocyte hypertrophy associated with cell-cycle progression, polyploidy, and altered expression of cell-cycle regulators p53, Cyclin-D1, and p27. Because circulating reproductive hormones and bile acids are raised in normal pregnant women and can cause liver growth in rodents, these compounds are candidates for the signal driving gestational liver enlargement in rodents. Administration of pregnancy levels of reproductive hormones was not sufficient to cause liver growth, but mouse pregnancy was associated with increased serum bile acid levels. It is known that the bile acid sensor Fxr is required for normal recovery from partial hepatectomy, and we demonstrate that Fxr(-/-) mice undergo gestational liver growth by adaptive hepatocyte hyperplasia. This is the first identification of any component that is required to maintain the normal mechanisms of gestational hepatomegaly and also implicates Fxr in a physiologically normal process that involves control of the hepatocyte cell cycle. Understanding pregnancy-induced hepatocyte hypertrophy in mice could suggest mechanisms for safely increasing functional liver capacity in women during increased metabolic demand.

2010

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Consumption of low-carbohydrate, high-protein, high-fat diets lead to rapid weight loss but the cardioprotective effects of these diets have been questioned. We examined the impact of high-protein and high-fat diets on cholesterol metabolism by comparing the plasma cholesterol and the expression of cholesterol biosynthesis genes in the liver of mice fed a high-fat (HF) diet that has a high (H) or a low (L) protein-to-carbohydrate (P/C) ratio. H-P/C-HF feeding, compared with L-P/C-HF feeding, decreased plasma total cholesterol and increased HDL cholesterol concentrations at 4-wk. Interestingly, the expression of genes involved in hepatic steroid biosynthesis responded to an increased dietary P/C ratio by first down-regulation (2-d) followed by later up-regulation at 4-wk, and the temporal gene expression patterns were connected to the putative activity of SREBF1 and 2. In contrast, Cyp7a1, the gene responsible for the conversion of cholesterol to bile acids, was consistently up-regulated in the H-P/C-HF liver regardless of feeding duration. Over expression of Cyp7a1 after 2-d and 4-wk H-P/C-HF feeding was connected to two unique sets of transcription regulators. At both time points, up-regulation of the Cyp7a1 gene could be explained by enhanced activations and reduced suppressions of multiple transcription regulators. In conclusion, we demonstrated that the hypocholesterolemic effect of H-P/C-HF feeding coincided with orchestrated changes of gene expressions in lipid metabolic pathways in the liver of mice. Based on these results, we hypothesize that the cholesterol lowering effect of high-protein feeding is associated with enhanced bile acid production but clinical validation is warranted. (246 words)

Public Library of Science2012

Compromised intestinal lipid absorption in mice with a liver-specific deficiency of liver receptor homolog 1

Johan Auwerx, Chikage Mataki, Kristina Schoonjans

Bile acids (BAs) are water-soluble end products from cholesterol metabolism and are essential for efficient absorption of dietary lipids. By using targeted somatic mutagenesis of the nuclear receptor liver receptor homolog 1 (LRH-1) in mouse hepatocytes, we demonstrate here that LRH-1 critically regulates the physicochemical properties of BAs. The absence of LRH-1 and subsequent deficiency of Cyp8b1 eliminate the production of cholic acid and its amino acid conjugate taurocholic acid and increase the relative amounts of less amphipathic BA species. Intriguingly, while the expression of Cyp8b1 is almost extinguished in the livers of mice that lack LRH-1, the expression of the rate-limiting enzyme of BA synthesis, i.e., Cyp7a1, remains unchanged. The profound remodeling of the BA composition significantly reduces the efficacy of intestinal absorption of lipids and reuptake of BAs and facilitates the removal of lipids from the body. Our studies unequivocally demonstrate a pivotal role for LRH-1 in determining the composition of BAs, which, in turn has major consequences on whole-body lipid homeostasis.

2007