Propiconazole is a triazole fungicide previously shown to induce triglyceride accumulation in human liver HepaRG cells, potentially via activation of the Pregnane X Receptor (PXR). However, whether propiconazole can disrupt hepatic and whole-body metabolism in vivo is currently unknown. Therefore, we aimed to examine the metabolic effects of propiconazole in the context of metabolic dysfunction-associated steatotic liver disease (MASLD), obesity, and insulin resistance. To this end, male C57BL/6J mice were fed a high-fat diet for 20 weeks. During the last 10 weeks, mice additionally received vehicle, 0.04, 30, or 100 mg/kg body weight (bw)/day propiconazole via oral gavage. High-dose propiconazole, but not low or intermediate dose, reduced body weight gain and adipose tissue weight in obese mice. Mice receiving high-dose propiconazole displayed improved glucose tolerance and reduced levels of plasma triglycerides and cholesterol. Propiconazole dose-dependently increased liver weight and triglyceride levels and at high dose caused signs of hepatic inflammation. RNA sequencing on the liver revealed that propiconazole mainly induced PXR target genes. At intermediate and high dose, propiconazole induced pathways related to cell-cell interactions and inflammation, while oxidative phosphorylation was repressed by propiconazole. Comparison of gene regulation in wildtype and PXR knockout primary hepatocytes as well as gene reporter assays confirmed the activation of PXR by propiconazole. All in all, our data underscore the capacity of propiconazole to activate PXR in the liver and thereby promote the development of hepatic steatosis in vivo.

• Klíčová slova
• Lipid metabolism, Liver, MASLD, Metabolism disrupting chemicals (MDCs), Nuclear receptors/PXR, Propiconazole,
• MeSH
• dieta s vysokým obsahem tuků škodlivé účinky   MeSH
• inzulinová rezistence MeSH
• játra účinky léků   metabolismus   patologie   MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• obezita * chemicky indukované   metabolismus   etiologie   MeSH
• pregnanový X receptor * metabolismus   genetika   MeSH
• průmyslové fungicidy * toxicita   aplikace a dávkování   MeSH
• triazoly * toxicita   aplikace a dávkování   MeSH
• triglyceridy krev   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• ztučnělá játra * chemicky indukované   metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• pregnanový X receptor * MeSH
• propiconazole MeSH Prohlížeč
• průmyslové fungicidy * MeSH
• triazoly * MeSH
• triglyceridy MeSH

The pregnane X receptor (PXR, NR1I2) is a xenobiotic-activated transcription factor with high levels of expression in the liver. It not only plays a key role in drug metabolism and elimination, but also promotes tumor growth, drug resistance, and metabolic diseases. It has been proposed as a therapeutic target for type II diabetes, metabolic syndrome, and inflammatory bowel disease, and PXR antagonists have recently been considered as a therapy for colon cancer. There are currently no PXR antagonists that can be used in a clinical setting. Nevertheless, due to the large and complex ligand-binding pocket (LBP) of the PXR, it is challenging to discover PXR antagonists at the orthosteric site. Alternative ligand binding sites of the PXR have also been proposed and are currently being studied. Recently, the AF-2 allosteric binding site of the PXR has been identified, with several compounds modulating the site discovered. Herein, we aimed to summarize our current knowledge of allosteric modulation of the PXR as well as our attempt to unlock novel allosteric sites. We describe the novel binding function 3 (BF-3) site of PXR, which is also common for other nuclear receptors. In addition, we also mention a novel allosteric site III based on in silico prediction. The identified allosteric sites of the PXR provide new insights into the development of safe and efficient allosteric modulators of the PXR receptor. We therefore propose that novel PXR allosteric sites might be promising targets for treating chronic metabolic diseases and some cancers.

• Klíčová slova
• AF-2 site, BF-3 site, CAR, PAM-antagonist, PXR, allosteric site, pregnane X receptor,
• MeSH
• alosterické místo MeSH
• diabetes mellitus 2. typu * MeSH
• furylfuramid MeSH
• lidé MeSH
• ligandy MeSH
• pregnanový X receptor MeSH
• receptory cytoplazmatické a nukleární MeSH
• steroidní receptory * metabolismus   MeSH
• xenobiotika MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• furylfuramid MeSH
• ligandy MeSH
• pregnanový X receptor MeSH
• receptory cytoplazmatické a nukleární MeSH
• steroidní receptory * MeSH
• xenobiotika MeSH

Bile acids (BAs) are key signaling steroidal molecules that regulate glucose, lipid, and energy homeostasis via interactions with the farnesoid X receptor (FXR) and G-protein bile acid receptor 1 (GPBAR1). Extensive medicinal chemistry modifications of the BA scaffold led to the discovery of potent selective or dual FXR and GPBAR1 agonists. Herein, we discovered 7-ethylidene-lithocholic acid (7-ELCA) as a novel combined FXR antagonist/GPBAR1 agonist (IC50 = 15 μM/EC50 = 26 nM) with no off-target activation in a library of 7-alkyl substituted derivatives of BAs. 7-ELCA significantly suppressed the effect of the FXR agonist obeticholic acid in BSEP and SHP regulation in human hepatocytes. Importantly, 7-ELCA significantly stimulated the production of glucagon-like peptide-1 (GLP-1), an incretin with insulinotropic effect in postprandial glucose utilization, in intestinal enteroendocrine cells. We can suggest that 7-ELCA may be a prospective approach to the treatment of type II diabetes as the dual modulation of GPBAR1 and FXR has been supposed to be effective in the synergistic regulation of glucose homeostasis in the intestine.

• Klíčová slova
• G protein-coupled bile acid receptor 1, bile acids, farnesoid X receptor, metabolism, steroid,
• Publikační typ
• časopisecké články MeSH