This study aims to develop an improved cell screening system for farnesoid X receptor (FXR) agonists based on a dual luciferase reporter gene system. FXR response element (FXRE) fragments from FXR target genes were cloned and inserted into upstream of firefly luciferase (Luc) gene in the plasmid pGL4-luc2P-Hygro. In combination with the internal reference plasmid containing renilla luciferase, a dual luciferase reporter gene system was developed and used for high throughput screening of FXR agonists. After studying the effects of over-expression of RXR, mouse or human FXR, various FXRE fragments, and different ratio of FXR plasmid amount to reporter gene plasmid, induction efficiency of the screening system was optimized by the known FXR agonist GW4064, and Z factor for the system reached 0.83 under optimized conditions. In summary, an improved cell screening system based on double luciferase reporter gene detection system was developed to facilitate the discovery of FXR agonists, where a new enhanced FXRE element was formed by a superposition of multiple FXRE fragments from FXR target genes, instead of a superposition of traditional IR-1 (inverted repeats-1) fragments.
Humans ; Mice ; Animals ; Transcription Factors/genetics* ; DNA-Binding Proteins/genetics* ; Receptors, Cytoplasmic and Nuclear/genetics* ; Genes, Reporter ; Luciferases/genetics*

Non-alcoholic fatty liver disease(NAFLD) is a chronic metabolic condition with rapidly increasing incidence, becoming a public health issue of worldwide concern. Studies have shown that farnesoid X receptor(FXR)-based modulation of downstream targets can improve liver function and metabolic status in the patients with NAFLD and may be a potential drug target for treating this di-sease. Great progress has been achieved in the development of drugs targeting FXR for the treatment of NAFLD. A number of studies have explored the traditional Chinese medicine and their active ingredients for the treatment of NAFLD via FXR considering the high safety and efficacy and mild side effects. This paper systematically describes the mechanism of traditional Chinese medicines in the treatment of NAFLD via FXR and the downstream targets, aiming to provide precise targets for the drug development and clinical treatment of NAFLD.
Humans ; Non-alcoholic Fatty Liver Disease/metabolism* ; Liver ; Medicine, Chinese Traditional/adverse effects* ; Receptors, Cytoplasmic and Nuclear/metabolism*

Nuclear receptor subfamily 2, group F, member 6 (NR2F6) is a member of orphan nuclear receptors, which is expressed in major tissues and organs of the human body, and plays an important role in the regulation of various biological functions and gene expressions. Recent studies have shown that the expression of NR2F6 was up-regulated in a variety of malignant tumors and showed significant correlations with cancer progression. These findings triggered the widespread interest in understanding the relationship between NR2F6 and cancer development and progression. In addition, the latest studies have underscored that NR2F6 was involved in enhancing antitumor immune responses that could serve as a potential target for immune regulation. This review summarizes the biological functions of NR2F6 and its role in tumors, with the aim to provide new insights into effective cancer therapies.
Gene Expression Regulation ; Humans ; Neoplasms/genetics* ; Receptors, Cytoplasmic and Nuclear/genetics* ; Repressor Proteins/genetics* ; Transcription Factors/genetics*

Farnesoid X receptor (FXR) has been identified as an inhibitor of platelet function and an inducer of fibrinogen protein complex. However, the regulatory mechanism of FXR in hemostatic system remains incompletely understood. In this study, we aimed to investigate the functions of FXR in regulating antithrombin III (AT III). C57BL/6 mice and FXR knockout (FXR KO) mice were treated with or without GW4064 (30 mg/kg per day). FXR activation significantly prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT), lowered activity of activated factor X (FXa) and concentrations of thrombin-antithrombin complex (TAT) and activated factor II (FIIa), and increased level of AT III, whereas all of these effects were markedly reversed in FXR KO mice. In vivo, hepatic AT III mRNA and protein expression levels were up-regulated in wild-type mice after FXR activation, but down-regulated in FXR KO mice. In vitro study showed that FXR activation induced, while FXR knockdown inhibited, AT III expression in mouse primary hepatocytes. The luciferase assay and ChIP assay revealed that FXR can bind to the promoter region of AT III gene where FXR activation increased AT III transcription. These results suggest FXR activation inhibits coagulation process via inducing hepatic AT III expression in mice. The present study reveals a new role of FXR in hemostatic homeostasis and indicates that FXR might act as a potential therapeutic target for diseases related to hypercoagulation.
Animals ; Antithrombin III ; Blood Coagulation ; Hepatocytes ; Liver ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Receptors, Cytoplasmic and Nuclear/genetics*

Patients with diabetes mellitus (DM) often suffer from diverse skin disorders, which might be attributable to skin barrier dysfunction. To explore the role of lipid alterations in the epidermis in DM skin disorders, we quantitated 49 lipids (34 ceramides, 14 free fatty acids (FFAs), and cholesterol) in the skin epidermis, liver, and kidneys of db/db mice, a Type 2 DM model, using UPLC-MS/MS. The expression of genes involved in lipid synthesis was also evaluated. With the full establishment of hyperglycemia at the age of 20 weeks, remarkable lipid enrichment was noted in the skin of the db/db mice, especially at the epidermis and subcutaneous fat bed. Prominent increases in the ceramides and FFAs (>3 fold) with short or medium chains (nuclear receptors promoting lipid synthesis, lipid synthesis enzymes such as elongases 1, 4, and 6, and fatty acid synthase and stearoyl-CoA desaturase were highly expressed in the skin and livers of the db/db mice. Collectively, our study demonstrates an extensive alteration in the skin and systemic lipid profiles of db/db mice, which could contribute to the development of skin disorders in DM.
Animals ; Ceramides ; Diabetes Mellitus ; Diabetes Mellitus, Type 2 ; Epidermis ; Fatty Acids, Nonesterified ; Humans ; Hyperglycemia ; Kidney ; Liver ; Mice ; Receptors, Cytoplasmic and Nuclear ; Skin ; Stearoyl-CoA Desaturase ; Subcutaneous Fat

To explore the effect of geniposidic acid (GPA) on the signal pathway of small heterodimer dimer receptor (SHP) and liver receptor homologue 1 (LRH-1) in cholestasis rats induced by alpha-naphthalene isothiocyanate (ANIT).
 Methods: Fifty SD rats were randomly divided into five groups: a blank group, an ANIT group, an ANIT+GPA (100 mg/kg) group, an ANIT+GPA (50 mg/kg) group, and an ANIT+GPA (25 mg/kg) group (n=10 in each group). The GPA were intragastrically given to rats for 10 days, and the control group and the ANIT group were given normal saline. At the eighth day of administration, all rats except the blank group were given 65 mg/kg ANIT once until the tenth day. After the last administration, serum total cholesterol (TC), triglyceride (TG) and total bile acids (TBA) were measured. The primary hepatocytes (RPH) were isolated from normal rats and cultured. The cells were divided into a blank group, an ANIT (40 μmol/L) group, an ANIT (40 μmol/L)+GPA (4.00 mmol/L) group (A4.00G group), an ANIT (40 μmol/L)+GPA (1.00 mmol/L) group (A1.00G group), and an ANIT (40 μmol/L)+GPA (0.25 mmol/L) group (A0.25G group). The mRNA transcription levels of SHP and cholesterol 7 alpha hydroxylase (CYP7A1) in RPH were detected by real-time-PCR, and the protein levels of SHP and CYP7a1 were detected by Western blotting. In the LRH-1 silence experiment, the RPH were divided into a blank group, a negative transfection group, a siRNA-LRH group (ZR group), a siRNA-LRH+GPA (4.00 mmol/L) group (ZR4.00G group), a siRNA-LRH+GPA (1.00 mmol/L) group (ZR1.00G group) and a siRNA-LRH+GPA (0.25 mmol/L) group (ZR0.25G group). The protein and mRNA levels of SHP, CYP7a1, LRH-1 were detected. In the over-expression experiment, the RPH were also divided into a blank group, a negative transfection group, a LRH-1 over-expression plasmid group (OE group), a LRH-1 over-expression plasmid+GPA (4.00 mmol/L) group (OE4.00G group), a LRH-1 over-expression plasmid+GPA (1.00 mmol/L) group (OE1.00G group), and a LRH-1 over-expression plasmid+GPA (0.25 mmol/L) group (OE0.25G group). The protein and mRNA levels of SHP, CYP7a1 and LRH-1 were detected.
 Results: Compared with the blank control group, TC and TBA were significantly increased (both P<0.01) in the ANIT group, but there was no difference in TG; compared with the ANIT group, the contents of TC and TBA in the AG100 and AG50 groups were significantly reduced (all P<0.01). Compared with the blank control group, the proteins and mRNA levels of SHP were significantly decreased (P<0.01), while CYP7a1 were dramatically increased (P<0.01) in the ANIT group; compared with the ANIT group, the proteins and mRNA levels of SHP in the A4.00G group and the A1.00G group were significantly increased (both P<0.01), while the levels of CYP7a1 proteins and mRNA levels were evidently decreased in the A4.00G and A1.00G groups (both P<0.01). Compared with the negative transfection group, the proteins and mRNA levels of CYP7a1 and LRH-1 were dramatically restrained (all P<0.01), while there was no change in SHP in the ZR group; compared with the ZR group, the proteins and mRNA levels of SHP were significantly increased (all P<0.01), while LRH-1 and CYP7a1 were not changed in the ZR4.00G, ZR1.00G and ZR0.25G groups. Compared with the negative transfection group, the protein and mRNA levels of CYP7a1 and LRH-1 were significantly suppressed in the OE group (all P<0.01). Compared with the OE group, the protein and mRNA levels of SHP were evidently increased in the OE4G and OE1G groups (all P<0.01), while LRH-1 and CYP7a1 were not changed in the OE4G, OE1G and OE0.25G groups.
 Conclusion: The over-expression of LRH-1 in RPH can up-regulate the mRNA and protein levels of CYP7a1. GPA can improve the biochemical and liver pathology of ANIT-induced cholestasis rats, which may be related to the decrease of CYP7a1 by activating SHP through LRH-1 in RPH.
Animals ; Cholestasis ; Iridoid Glucosides ; Rats ; Rats, Sprague-Dawley ; Receptors, Cytoplasmic and Nuclear ; Signal Transduction

OBJECTIVE: To detect mutation of LBR gene in a pedigree affected with Pelger-Huёt anomaly (PHA) and to explore its clinical characteristics. METHODS: Genomic DNA was extracted from the pedigree and healthy controls. The 14 exons of the LBR gene were subjected to PCR amplification and Sanger sequencing. Suspected mutations were verified in other family members and 100 healthy controls. Polyphen-2 and SIFT software were used to predict the effect of the mutation, and Swiss-model software was used to simulate the protein structure. RESULTS: Three patients were found to carry a c.893G>A mutation in exon 8 of the LBR gene, which resulted in substitution of the 298th amino acid residue glycine by glutamic acid (p.Gly298Glu). The same mutation was not found in healthy family members and 100 healthy controls. The mutation was predicted to be damaging. Bioinformatic simulation showed the mutation has altered the 3D structure of the LBR protein. CONCLUSION The c.893G>A (p.Gly298Glu) mutation in the LBR gene probably underlies the PHA in this pedigree and has enriched the spectrum of LBR gene mutations.
Case-Control Studies ; DNA Mutational Analysis ; Exons ; Humans ; Mutation ; Pedigree ; Pelger-Huet Anomaly ; genetics ; Polymerase Chain Reaction ; Receptors, Cytoplasmic and Nuclear ; genetics

To investigate the effects of geniposidic acid( GPA) on hepato-enteric circulation in cholestasis rats,and to explore the mechanism based on the sirtuin 1( Sirt1)-farnesol X receptor( FXR) pathway,sixty SD rats were randomly divided into 6 groups:blank control group,ANIT model group,ursodeoxycholic acid group( 100 mg·kg~(-1)·d-1 UDCA),and GPA high,medium and low( 100,50 and 25 mg·kg~(-1)·d-1) dosage groups,10 rats in each group. Corresponding drugs were intragastrically( ig) administered for10 days. After administration on day 8,all rats except blank rats were administered with 65 mg·kg~(-1)α-naphthalene isothiocyanate( ANIT) once. After the last administration,the serum levels of alanine aminotransferase( ALT),glutamine oxalacetate aminotransferase( AST),gamma-glutamyltransferase( γ-GGT),alkaline phosphatase( ALP),total bilirubin( TB) and total bile acid( TBA)were measured,and the mRNA transcription levels of Sirt1,FXR,multidrug resistant associated protein 2( MRP2),bile salt export pump( BSEP),sodium taurocholate contractible polypeptide( NTCP) in liver and apical sodium bile acid transporter( ASBT),ileum bile acid binding protein( IBABP) in ileum were detected by reverse transcription-polymerase chain reaction( RT-PCR). The protein expression levels of Sirt1,FXR and NTCP were detected by Western blot; the expression of MRP2,BSEP in liver and ASBT,IBABP in ileum were determined by immunofluorescence three staining. Primary rat hepatocytes were cultured in vitro to investigate the inhibitory effect of GPA on a potent and selective Sirt1 inhibitor( EX 527),and the mRNA and protein expression levels of Sirt1 and FXR were detected by RT-PCR and Western blot. GPA significantly decreased the levels of ALT,AST,γ-GGT,ALP,TB,TBA in serum( P<0.01) and improved the pathological damage of liver tissues in ANIT-induced cholestasis rats; significantly increased the mRNA and protein expression levels of Sirt1,FXR,MRP2,BSEP,NTCP in liver and ASBT,IBABP in ileum( P< 0.01). In vitro primary hepatocytes experiment indicated that the gene and protein expression levels of FXR and Sirt1 were noticeably improved by GPA in primary hepatocytes inhibited by EX-527( P<0.01). It was found that the improvement of GPA was in a dose-dependent manner. GPA could improve bile acid hepatointestinal circulation and play a liver protection and cholagogu role in cholestasis rats induced by ANIT.The mechanism may be that GPA activated FXR by regulating Sirt1,a key regulator of oxidative stress injury,and then the activated FXR could regulate protein of bile acid hepato-enteric circulation.
Animals ; Cholestasis ; Iridoid Glucosides ; Liver ; Rats ; Rats, Sprague-Dawley ; Receptors, Cytoplasmic and Nuclear ; Signal Transduction ; Sirtuin 1

Diabetes and obesity have reached an epidemic status worldwide. Diabetes increases the risk for cardiovascular disease and non-alcoholic fatty liver disease. Primary bile acids are synthesized in hepatocytes and are transformed to secondary bile acids in the intestine by gut bacteria. Bile acids are nutrient sensors and metabolic integrators that regulate lipid, glucose, and energy homeostasis by activating nuclear farnesoid X receptor and membrane Takeda G protein-coupled receptor 5. Bile acids control gut bacteria overgrowth, species population, and protect the integrity of the intestinal barrier. Gut bacteria, in turn, control circulating bile acid composition and pool size. Dysregulation of bile acid homeostasis and dysbiosis causes diabetes and obesity. Targeting bile acid signaling and the gut microbiome have therapeutic potential for treating diabetes, obesity, and non-alcoholic fatty liver disease.
Bacteria ; Bile Acids and Salts ; Bile ; Cardiovascular Diseases ; Dysbiosis ; Gastrointestinal Microbiome ; Glucose ; Hepatocytes ; Homeostasis ; Intestines ; Membranes ; Non-alcoholic Fatty Liver Disease ; Obesity ; Receptors, Cytoplasmic and Nuclear ; Receptors, G-Protein-Coupled

Over the past decade, there has been increasing attention on the interaction between microbiota and bile acid metabolism. Bile acids are not only involved in the metabolism of nutrients, but are also important in signal transduction for the regulation of host physiological activities. Microbial-regulated bile acid metabolism has been proven to affect many diseases, but there have not been many studies of disease regulation by microbial receptor signaling pathways. This review considers findings of recent research on the core roles of farnesoid X receptor (FXR), G protein-coupled bile acid receptor (TGR5), and vitamin D receptor (VDR) signaling pathways in microbial-host interactions in health and disease. Studying the relationship between these pathways can help us understand the pathogenesis of human diseases, and lead to new solutions for their treatments.
Bile Acids and Salts/metabolism* ; Gastrointestinal Microbiome ; Humans ; Inflammation/metabolism* ; Metabolic Syndrome/metabolism* ; Receptors, Calcitriol/physiology* ; Receptors, Cytoplasmic and Nuclear/physiology* ; Receptors, G-Protein-Coupled/physiology* ; Signal Transduction/physiology*