Animals ; Humans ; Oxazines ; metabolism ; Phenylpropionates ; metabolism ; Receptors, Cytoplasmic and Nuclear ; agonists ; antagonists & inhibitors ; Thiazolidinediones ; metabolism ; Transcription Factors ; agonists ; antagonists & inhibitors

OBJECTIVETo investigate the effect of FXR on scavenger receptor class B type I (SR-BI) expression.

METHODSHuman vascular endothelium Eahy926 cells were treated with FXR agonist androsterone, and the specific target gene of FXR SHP mRNA was detected by RT-PCR. SR-BI mRNA and protein were determined using RT-PCR, real-time PCR and Western blotting.

RESULTSThe level of SHP mRNA in Eahy926 cells increased after androsterone treatment at different concentrations for 24 h, demonstrating FXR activation in the cells. RT-PCR, real-time PCR and Western blotting detected increased SR-BI expression at both mRNA and protein levels after FXR activation.

CONCLUSIONFXR increases the expression of SR-BI in human vascular endothelium cells.

Androsterone ; pharmacology ; Cell Line ; Endothelial Cells ; drug effects ; metabolism ; Humans ; Receptors, Cytoplasmic and Nuclear ; agonists ; metabolism ; Scavenger Receptors, Class B ; metabolism

OBJECTIVETo investigate the effects of GW4064, a farnesoid X receptor (FXR) agonist, on adiponectin and its receptors during the differentiation of 3T3-L1 preadipocytes and on adiponectin receptors in HepG2 cells.

METHODSThe mRNA expressions of FXR, PPARγ2, adiponectin, AdipoR1, and AdipoR2 and the protein levels of adiponectin on days 0, 2, 4, 6, and 8 during the differentiation of 3T3-L1 preadipocytes treated with GW4064 were detected by fluorescent real-time PCR and ELISA, respectively. The mRNA expressions of AdipoR1 and AdipoR2 in HepG2 cells were also examined at 0, 12, 24, and 48 h after GW4064 treatment.

RESULTSThe mRNA expressions of FXR, PPARγ2, adiponectin, and AdipoR2 in 3T3-L1 preadipocytes and AdipoR2 in HepG2 cells treated with GW4064 was significantly increased compared with the control group (all P<0.05). The protein level of adiponectin was also significantly increased after GW4064 treatment. The expression of AdipoR1 in either 3T3-L1 preadipocytes or HepG2 cells showed no significant changes after GW4064 treatment.

CONCLUSIONGW4064 can up-regulate the expressions of FXR, PPARγ2, adiponectin, AdipoR2 in 3T3-L1 preadipocytes and AdipoR2 in HepG2 cells. As adiponectin and its receptors are two important factors in the treatment of non-alcoholic fatty liver disease, FXR agonist may potentially produce therapeutic effect on non-alcoholic fatty liver disease and can regulate adipocytes via up-regulating PPARγ during adipocyte differentiation.

3T3-L1 Cells ; Adiponectin ; metabolism ; Animals ; Cell Differentiation ; drug effects ; Hep G2 Cells ; Humans ; Isoxazoles ; pharmacology ; Mice ; PPAR gamma ; metabolism ; Receptors, Adiponectin ; metabolism ; Receptors, Cytoplasmic and Nuclear ; agonists

Several new drug targets of anti-atherosclerosis, emerging in the recent years, such as PPAR agonists, cholesteryl ester transfer protein (CETP) inhibitors, infusion of apolipoprotein A-I (apoA-I), liver X receptor (LXR) activators and phospholipid transfer protein (PLTP) inhibitors etc were reviewed.
Apolipoprotein A-I ; therapeutic use ; Atherosclerosis ; drug therapy ; metabolism ; Benzoates ; chemistry ; therapeutic use ; Benzylamines ; chemistry ; therapeutic use ; Cholesterol Ester Transfer Proteins ; antagonists & inhibitors ; metabolism ; DNA-Binding Proteins ; agonists ; metabolism ; Humans ; Liver X Receptors ; Molecular Structure ; Orphan Nuclear Receptors ; Oxazines ; chemistry ; therapeutic use ; Peroxisome Proliferator-Activated Receptors ; agonists ; metabolism ; Phenylpropionates ; chemistry ; therapeutic use ; Quinolines ; chemistry ; therapeutic use ; Receptors, Cytoplasmic and Nuclear ; agonists ; metabolism

We investigated the mechanism of spontaneous cholesterol efflux induced by acyl-coenzyme A:cholesterol acyltransferase (ACAT) inhibition, and how an alteration of cholesterol metabolism in macrophages impacts on that in HepG2 cells. Oleic acid anilide (OAA), a known ACAT inhibitor reduced lipid storage substantially by promotion of cholesterol catabolism and repression of cholesteryl ester accumulation without further increase of cytotoxicity in acetylated low-density lipoprotein-loaded THP-1 macrophages. Analysis of expressed mRNA and protein revealed that cholesterol 7alpha-hydroxylase (CYP7A1), oxysterol 7alpha- hydroxylase (CYP7B1), and cholesterol 27-hydroxylase (CYP27) were highly induced by ACAT inhibition. The presence of a functional cytochrome P450 pathway was confirmed by quantification of the biliary cholesterol mass in cell monolayers and extracelluar medium. Notably, massively secreted biliary cholesterol from macrophages suppressed the expression of CYP7 proteins in a farnesoid X receptor (FXR)-dependent manner in HepG2 cells. The findings reported here provide new insight into mechanisms of spontaneous cholesterol efflux, and suggest that ACAT inhibition may stimulate cholesterol-catabolic (cytochrome P450) pathway in lesion-macrophages, in contrast, suppress it in hepatocyte via FXR induced by biliary cholesterol (BC).
Anilides/*pharmacology ; Bile/metabolism ; Cells, Cultured ; Cholesterol/*metabolism ; Cholesterol Esters/metabolism ; DNA-Binding Proteins/agonists/*metabolism ; Enzyme Inhibitors/pharmacology ; Gene Expression Regulation, Enzymologic/drug effects ; Hepatocytes/*drug effects/metabolism ; Humans ; Lipid Metabolism/drug effects/genetics ; Macrophages/*drug effects/metabolism ; Models, Biological ; Oleic Acids/*pharmacology ; Receptors, Cytoplasmic and Nuclear/agonists/*metabolism ; Sterol O-Acyltransferase/*antagonists & inhibitors/physiology ; Transcription Factors/agonists/*metabolism

OBJECTIVETo investigate the effects and mechanism of farnesoid X receptor (FXR) and its ligands on the metabolism of bile acids in rats with estrogen-induced intrahepatic cholestasis of pregnancy (ICP).

METHODSAn ICP rat model was established with estradiol benzoate (EB) injections. Then FXR ligand chenodeoxycholic acid (CDCA) was administrated (100 mg/kg daily) to ICP rats for 5 days. The serum TBA and expression of FXR and bile salt export pump (BSEP) in the rat livers were examined by immunohistochemistry and reverse transcription PCR.

RESULTSThe levels of TBA in the CDCA group rats were significantly lower than the untreated rats [(17.2+/-4.1)micromol/L vs (29.3+/-6.4)micromol/L], and the expressions of mRNA and protein of FXR were significantly higher [(0.76+/-0.09 vs 0.53+/-0.06, P<0.05 and 2.35+/-0.06 vs 1.83+/-0.05, P<0.017, respectively)], and the expressions of BSEP were also higher [(0.99+/-0.21 vs 0.76+/-0.07, P<0.017 and 1.88+/-0.03 vs 1.46+/-0.06, P<0.017, respectively)].

CONCLUSIONSFXR plays an important role in modulating the metabolism of bile acids. CDCA can lower the levels of serum TBA by upregulating the expression of FXR and BSEP and then increasing the transport of the bile acids. These facts might present a new idea and target for the treatment of ICP.

Animals ; Bile Acids and Salts ; metabolism ; Chenodeoxycholic Acid ; pharmacology ; Cholestasis, Intrahepatic ; chemically induced ; genetics ; metabolism ; Estrogens ; pharmacology ; Female ; Pregnancy ; Pregnancy Complications ; chemically induced ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Cytoplasmic and Nuclear ; agonists

The nuclear receptors, steroid and xenobiotic receptor (SXR) and constitutive androstane receptor (CAR) play important functions in mediating lipid and drug metabolism in the liver. The present study demonstrates modulatory actions of estrogen in transactivations of SXR-mediated liver X receptor response element (LXRE) and CAR-mediated phenobarbital response element (PBRU). When human estrogen receptor (hERalpha) and SXR were exogenously expressed, treatment with either rifampicin or corticosterone promoted significantly the SXR-mediated transactivation of LXRE reporter gene in HepG2. However, combined treatment with estrogen plus either rifampicin or corticosterone resulted in less than 50% of the mean values of the transactivation by rifampicin or corticosterone alone. Thus, it is suggested that estrogen may repress the SXR-mediated transactivation of LXRE via functional cross-talk between ER and SXR. The CAR-mediated transactivation of PBRU was stimulated by hERalpha in the absence of estrogen. However, the potentiation by CAR agonist, TCPOBOP, was significantly repressed by moxestrol in the presence of ER. Thus, ER may play both stimulatory and inhibitory roles in modulating CAR-mediated transactivation of PBRU depending on the presence of their ligands. In summary, this study demonstrates that estrogen modulates transcriptional activity of SXR and CAR in mediating transactivation of LXRE and PBRU, respectively, of the nuclear receptor target genes through functional cross-talk between ER and the corresponding nuclear receptors.
Corticosterone/pharmacology ; Estrogens/*metabolism ; Ethinyl Estradiol/analogs & derivatives/pharmacology ; Hep G2 Cells ; Humans ; Liver/*metabolism ; Orphan Nuclear Receptors/metabolism ; Phenobarbital/metabolism ; Pyridines/pharmacology ; Receptor Cross-Talk ; Receptors, Cytoplasmic and Nuclear/agonists/*metabolism ; Receptors, Steroid/*metabolism ; Response Elements ; Rifampin/pharmacology ; Transcriptional Activation/*drug effects/physiology

To determine whether the PPARalpha agonist fenofibrate regulates obesity and lipid metabolism with sexual dimorphism, we examined the effects of fenofibrate on body weight, white adipose tissue (WAT) mass, circulating lipids, and the expression of PPARalpha target genes in both sexes of high fat diet-fed C57BL/6J mice. Both sexes of mice fed a high-fat diet for 14 weeks exhibited increases in body weight, visceral WAT mass, as well as serum triglycerides and cholesterol, although these effects were more pronounced among males. Feeding a high fat diet supplemented with fenofibrate (0.05% w/w) reduced all of these effects significantly in males except serum cholesterol level. Females on a fenofibrate-enriched high fat diet had reduced serum triglyceride levels, albeit to a smaller extent compared to males, but did not exhibit decreases in body weight, WAT mass, and serum cholesterol. Fenofibrate treatment resulted in hepatic induction of PPAR alpha target genes encoding enzymes for fatty acid beta-oxidation, the magnitudes of which were much higher in males compared to females, as evidenced by results for acyl-CoA oxidase, a first enzyme of the beta-oxidation system. These results suggest that observed sexually dimorphic effects on body weight, WAT mass and serum lipids by fenofibrate may involve sexually related elements in the differential activation of PPARalpha.
Adipose Tissue/drug effects/metabolism ; Animals ; Body Composition/drug effects ; Body Weight/drug effects ; Diet ; Dietary Fats/pharmacology ; Female ; Gene Expression Regulation/drug effects ; Lipids/blood/*metabolism ; Liver/drug effects/metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Obesity/*metabolism/pathology ; Organ Weight/drug effects ; Procetofen/*pharmacology ; Receptors, Cytoplasmic and Nuclear/*agonists ; *Sex Characteristics ; Time Factors ; Transcription Factors/*agonists

To study the expression of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in lung cancer cells, and to testify if the PPAR-gamma agonists can inhibit human lung cancer cell growth through induction of apoptosis, PPAR-gamma was detected in two lung cancer cell lines by RT-PCR and immunohistochemistry, the inhibition of human lung cancer cell growth was investigated by MTT and cell counts, and the apoptosis was assessed by TUNEL. The results showed that: (1) PPAR-gamma expressed on two lung cancer cell lines; (2) PPAR-gamma activated by ligands could inhibit human lung cancer cell growth remarkably; (3) PPAR-gamma agonists could induce apoptosis to inhibit lung cancer cell growth. It was concluded that PPAR-gamma expressed in lung cancer cell can be activated by ligands and can inhibit lung cancer cell growth through induction of apoptosis.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Non-Small-Cell Lung ; pathology ; Carcinoma, Small Cell ; pathology ; Cell Division ; drug effects ; Gene Expression Regulation, Neoplastic ; Humans ; Ligands ; Lung Neoplasms ; pathology ; Prostaglandin D2 ; analogs & derivatives ; pharmacology ; Receptors, Cytoplasmic and Nuclear ; agonists ; metabolism ; Transcription Factors ; agonists ; metabolism ; Tumor Cells, Cultured

Vertical sleeve gastrectomy (VSG) is becoming more and more popular among the world. Despite its dramatic efficacy, however, the mechanism of VSG remains largely undetermined. This study aimed to test interferon (IFN)-γ secretion n of mesenteric lymph nodes in obese mice (ob/ob mice), a model of VSG, and its relationship with farnesoid X receptor (FXR) expression in the liver and small intestine, and to investigate the weight loss mechanism of VSG. The wild type (WT) mice and ob/ob mice were divided into four groups: A (WT+Sham), B (WT+VSG), C (ob/ob+Sham), and D (ob/ob+VSG). Body weight values were monitored. The IFN-γ expression in mesenteric lymph nodes of ob/ob mice pre- and post-operation was detected by flow cytometry (FCM). The FXR expression in the liver and small intestine was detected by Western blotting. The mouse AML-12 liver cells were stimulated with IFN-γ at different concentrations in vitro. The changes of FXR expression were also examined. The results showed that the body weight of ob/ob mice was significantly declined from (40.6±2.7) g to (27.5±3.8) g on the 30th day after VSG (P<0.05). At the same time, VSG induced a higher level secretion of IFN-γ in mesenteric lymph nodes of ob/ob mice than that pre-operation (P<0.05). The FXR expression levels in the liver and small intestine after VSG were respectively 0.97±0.07 and 0.84±0.07 fold of GAPDH, which were significantly higher than pre-operative levels of 0.50±0.06 and 0.48±0.06 respectively (P<0.05). After the stimulation of AML-12 liver cells in vitro by different concentrations of IFN-γ (0, 10, 25, 50, 100, and 200 ng/mL), the relative FXR expression levels were 0.22±0.04, 0.31±0.04, 0.39±0.05, 0.38±0.05, 0.56±0.06, and 0.35±0.05, respectively, suggesting IFN-γ could distinctly promote the FXR expression in a dose-dependent manner in comparison to those cells without IFN-γ stimulation (P<0.05). It was concluded that VSG induces a weight loss in ob/ob mice by increasing IFN-γ secretion of mesenteric lymph nodes, which then increases the FXR expression of the liver and small intestine.
Animals ; Body Weight ; Cell Line ; Gastrectomy ; methods ; Gene Expression ; Hepatocytes ; cytology ; drug effects ; metabolism ; Interferon-gamma ; biosynthesis ; pharmacology ; secretion ; Intestine, Small ; drug effects ; metabolism ; Liver ; drug effects ; metabolism ; Lymph Nodes ; drug effects ; metabolism ; Mesentery ; drug effects ; metabolism ; Mice ; Mice, Obese ; Obesity ; metabolism ; pathology ; surgery ; Receptors, Cytoplasmic and Nuclear ; agonists ; genetics ; metabolism ; Weight Loss