OBJECTIVE: To observe the effects of electroacupuncture (EA) at "Neiguan" (PC 6), "Guanyuan" (CV 4) and "Zusanli" (ST 36) on CYP7A1 expression in liver of rabbits with atherosclerosis (AS), and to explore the mechanism of acupuncture for prevention and treatment of atherosclerosis. METHODS: A total of 26 male rabbits were adaptively fed for 1 week in different cages. Seven rabbits were randomly divided into a blank group, and the remaining 19 rabbits were divided into a model group. The blank group was fed with normal diet, while the model group was fed with high-fat diet. After high-fat diet for 4 weeks, the rabbits in the model group were treated with balloon injury surgery of the common carotid artery; after surgery, the rabbits were fed with high-fat diet for 4 weeks. One rabbit was randomly selected from the blank group and model group to obtain the pathological section of carotid artery; the HE staining was used to observe the pathomorphology of atheromatous plaque to determine the success of modeling or not. After successful establishment of modeling, 18 rabbits were randomly divided into a AS model group, an EA group and a medication group, 6 rabbits in each one. The rabbits in the AS model group received no treatment; the rabbits in the medication group were treated with intragastric administration of atorvastatin calcium tablets; the rabbits in the EA group were treated with EA at "Neiguan" (PC 6), "Guanyuan" (CV 4) and "Zusanli" (ST 36), once a day, 20 min per treatment; six-day EA treatment constituted one course, and totally 4 courses were given with an interval of 1 day between courses. After treatment, vein blood was collected from rabbit ear, and cholesterol (CHO), triglyceride (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were measured in each group; the CYP7A1 protein expression in rabbit liver was measured by Western blot method, and CYP7A1 mRNA expression in rabbit liver was measured by RT-PCR. RESULTS: Compared with the blank group, the contents of CHO, TG and LDL in the AS model group were significantly increased, but HDL was significantly decreased, and the expression of CYP7A1 protein and CYP7A1 mRNA in the liver were significantly decreased (all <0.01). After treatment, compared with the model group, the contents of CHO, TG and LDL in the EA group and medication group were significantly reduced, but HDL was significantly increased, and the expression of CYP7A1 protein and CYP7A1 mRNA in the liver were significantly increased (all <0.01). The significant difference of each outcome between the EA group and medication group was not observed (all >0.05). CONCLUSION EA could significantly improve blood lipid and promote the expression of CYP7A1 mRNA in rabbits with atherosclerotic, which may be one of the mechanisms of EA for atherosclerosis.
Acupuncture Points ; Animals ; Atherosclerosis ; metabolism ; Cholesterol 7-alpha-Hydroxylase ; metabolism ; Electroacupuncture ; Humans ; Liver ; Male ; Rabbits ; Random Allocation ; Rats, Sprague-Dawley ; Triglycerides

Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily of ligand-activated transcription factors. As a metabolic regulator, FXR plays key roles in bile acid and cholesterol metabolism and lipid and glucose homeostasis. Therefore, FXR is a potential drug target for several metabolic syndromes, especially those related to lipidemia disorders. In the present study, we identified small molecule SIPI-7623, a derivative of an extract from Oriental wormwood (Artemisia capillaris), and found that it specifically upregulated the expression of cholesterol-7-alpha-hydroxylase (CYP7A1), downregulated the expression of sterol-regulatory element-binding protein 1c (SREBP-1c) in the liver, and inhibited the expression of ileal bile acid binding-protein (IBABP) in the ileum of rats. We found that inhibition of FXR by SIPI-7623 decreased the level of cholesterol and triglyceride. SIPI-7623 reduced the levels of cholesterol and triglyceride in in vitro HepG2 cell models, ameliorated diet-induced atherosclerosis, and decreased the serum lipid content on rats and rabbits model of atherosclerosis in vivo. Furthermore, SIPI-7623 decreased the extent of atherosclerotic lesions. Our resutls demonstrated that antagonism of the FXR pathway can be employed as a therapeutic strategy to treat metabolic diseases such as hyperlipidemia and atherosclerosis. In conclusion, SIPI-7623 could be a promising lead compound for development of drugs to treat hyperlipidemia and atherosclerosis.
Animals ; Artemisia ; chemistry ; Atherosclerosis ; drug therapy ; genetics ; metabolism ; Cholesterol ; metabolism ; Cholesterol 7-alpha-Hydroxylase ; genetics ; metabolism ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Hyperlipidemias ; drug therapy ; genetics ; metabolism ; Hypolipidemic Agents ; administration & dosage ; Liver ; drug effects ; metabolism ; Male ; Rabbits ; Rats ; Rats, Sprague-Dawley ; Receptors, Cytoplasmic and Nuclear ; antagonists & inhibitors ; genetics ; metabolism ; Sterol Regulatory Element Binding Protein 1 ; genetics ; metabolism ; Triglycerides ; metabolism

To study the effect of cholesterol and 25-OH-cholesterol on cholesterol metabolism in HepG2 cells and the effect of coptisine (Cop) extracted from Coptidis Rhizoma (CR) in reducing and regulating cholesterol. In this study, TC, TG, LDL-c and HDL-c were measured by biochemical analysis; mRNA and protein expressions of LDLR, HMGCR and CYP7A1 were detected by qRT-PCR and Western blot. According to the results, cholesterol and 25-OH-cholesterol inducing could decrease in mRNA and protein expressions of LDLR and CYP7A1, so as to increase TC and LDL-c contents. However, Cop could up-regulate mRNA and protein expressions of LDLR and CYP7A1 and down-regulate that of HMGCR, so as to reduce TC and LDL-c levels. These findings suggested that Cop has potential pharmacological activity for reducing cholesterol, and may reduce cholesterol by regulating mRNA and protein expressions of key genes involved in cholesterol metabolism, such as LDLR, CYP7A1 and HMGCR. This study laid a firm theoretical foundation for developing new natural drugs with the cholesterol-lowering activity.
Berberine ; analogs & derivatives ; pharmacology ; Cholesterol ; metabolism ; Cholesterol 7-alpha-Hydroxylase ; genetics ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation, Enzymologic ; drug effects ; Hep G2 Cells ; Humans ; Hydroxymethylglutaryl CoA Reductases ; genetics ; metabolism ; Receptors, LDL ; genetics ; metabolism ; Triglycerides ; metabolism

BACKGROUND: Expression of hepatic cholesterol 7alpha-hydroxylase (CYP7A1) is negatively regulated by orphan nuclear receptor small heterodimer partner (SHP). In this study, we aimed to find whether thyroid hormone regulates SHP expression by modulating the transcriptional activities of liver receptor homolog-1 (LRH-1). METHODS: We injected thyroid hormone (triiodothyronine, T3) to C57BL/6J wild type. RNA was isolated from mouse liver and used for microarray analysis and quantitative real-time polymerase chain reaction (PCR). Human hepatoma cell and primary hepatocytes from mouse liver were used to confirm the effect of T3 in vitro. Promoter assay and electrophoretic mobility-shift assay (EMSA) were also performed using human hepatoma cell line RESULTS: Initial microarray results indicated that SHP expression is markedly decreased in livers of T3 treated mice. We confirmed that T3 repressed SHP expression in the liver of mice as well as in mouse primary hepatocytes and human hepatoma cells by real-time PCR analysis. LRH-1 increased the promoter activity of SHP; however, this increased activity was markedly decreased after thyroid hormone receptor beta/retinoid X receptor alpha/T3 administration. EMSA revealed that T3 inhibits specific LRH-1 DNA binding. CONCLUSION: We found that thyroid hormone regulates the expression of SHP mRNA through interference with the transcription factor, LRH-1.
Animals ; Bile Acids and Salts ; Carcinoma, Hepatocellular ; Cell Line ; Child ; Child, Orphaned ; Cholesterol ; Cholesterol 7-alpha-Hydroxylase ; DNA ; Hepatocytes ; Humans ; Liver* ; Mice ; Microarray Analysis ; Real-Time Polymerase Chain Reaction ; Receptors, Thyroid Hormone ; RNA ; RNA, Messenger* ; Thyroid Gland* ; Thyroid Hormones ; Transcription Factors

BACKGROUND/OBJECTIVES: The purpose of the current study was to investigate the effect of red pericarp glutinous rice rich in polyphenols (Jakwangchalbyeo, red rice) on serum and hepatic levels of cholesterol and hepatic protein expression linked to synthesis and degradation of cholesterol in a hypercholesterolemic mice diet as compared with brown rice. MATERIALS/METHODS: C57BL/6 male mice were randomly divided into four groups (n = 5 each), which were fed different diets for a period of 12 weeks: American Institute of Nutrition (AIN)-93G diet, AIN-93G diet with 2% cholesterol, brown rice with 2% cholesterol, or red rice with 2% cholesterol. RESULT: Consumption of red rice resulted in a significant decrease in serum level of low-density lipoprotein cholesterol and hepatic levels of triglyceride and total-cholesterol. Expression of acyl-coenzyme A cholesterol acyltransferase-2 (ACAT-2), sterol regulatory element binding protein-2 (SREBP-2), and 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase was decreased, while expression of phosphorylated adenosine monophosphate activated protein kinase (p-AMPK)/AMPK ratio, cholesterol 7-alpha-hydroxylase (CYP7a1), and sterol 12-alpha-hydroxylase (CYP8b1) was increased in mice fed red rice. Brown rice had similar effects on cholesterol metabolism, but the effect of red rice was significantly greater than that of brown rice. CONCLUSIONS: The current study suggested that red rice had a hypocholesterolemic effect by lowering hepatic cholesterol synthesis through ACAT-2, HMG-CoA reductase, and SREBP-2, and by enhancing hepatic cholesterol degradation through CYP7a1 and CYP8b1 in mice fed a hypercholesterolemic diet.
Adenosine Monophosphate ; Animals ; Cholesterol 7-alpha-Hydroxylase ; Cholesterol* ; Coenzyme A ; Diet* ; Humans ; Lipoproteins ; Liver ; Male ; Metabolism* ; Mice* ; Oxidoreductases ; Phenol* ; Polyphenols ; Protein Kinases ; Steroid 12-alpha-Hydroxylase ; Triglycerides

Cholesterol 7alpha-hydroxylase (CYP7A1) regulates the balance between cholesterol supply and metabolism by catalyzing the rate-limiting step of bile acid biosynthesis. The transcriptional activity of CYP7A1 is tightly controlled by various nuclear receptors. A forkhead transcription factor O1 (FOXO1) plays a critical role in metabolism, and insulin inactivates FOXO1 through Akt-dependent phosphorylation and nuclear exclusion. We investigated the role of insulin-Akt-FOXO1 signaling pathway in CYP7A1 transcriptional regulation since we found putative insulin-response elements, FOXO1 binding sequences, in both rat and human CYP7A1 promoters. However, ectopic expression of FOXO1 increased the rat CYP7A1-, but mildly reduced human CYP7A1-promoter activities in a dose-dependent manner. Similarly to bile acids, insulin treatment increased small heterodimer partner (SHP) mRNA rapidly and transiently, leading to the suppression of CYP7A1 transcription in both human and rodents. Chromatin immunoprecipitation showed that FOXO1 directly bound to rat CYP1A1 promoter in the absence of insulin. FOXO1 binding to the rat promoter was diminished by insulin treatment as well as by expression of SHP. Our results suggest that the stimulation of insulin- signaling pathway of Akt-FOXO1 and SHP expression may regulate cholesterol/bile acid metabolisms in liver, linking carbohydrate and cholesterol metabolic pathways. A prolonged exposure of insulin in hyperinsulinemic insulin resistance or diabetic status represses CYP7A1 transcription and bile acid biosynthesis through SHP induction and FOXO1 inactivation, leading to impairment of the hepatic cholesterol/bile acid metabolisms.
Animals ; Bile Acids and Salts/metabolism ; Cholesterol/*metabolism ; Cholesterol 7-alpha-Hydroxylase/genetics/*metabolism ; Forkhead Transcription Factors/genetics/*metabolism ; Gene Expression Regulation/drug effects ; Glucose/*metabolism ; Hep G2 Cells ; Humans ; Insulin/pharmacology ; Lipid Metabolism/drug effects ; Liver/*metabolism/pathology ; Mice ; Mice, Inbred C57BL ; Mutagenesis, Site-Directed ; Nerve Tissue Proteins/genetics/*metabolism ; Protein Binding/drug effects/genetics ; Proto-Oncogene Proteins c-akt/metabolism ; Rats ; Receptors, Cytoplasmic and Nuclear/genetics/metabolism ; Sequence Deletion/genetics ; Signal Transduction/drug effects/genetics ; Transcriptional Activation/drug effects/genetics

Cholesterol 7alpha-hydroxylase (CYP7A1) regulates the balance between cholesterol supply and metabolism by catalyzing the rate-limiting step of bile acid biosynthesis. The transcriptional activity of CYP7A1 is tightly controlled by various nuclear receptors. A forkhead transcription factor O1 (FOXO1) plays a critical role in metabolism, and insulin inactivates FOXO1 through Akt-dependent phosphorylation and nuclear exclusion. We investigated the role of insulin-Akt-FOXO1 signaling pathway in CYP7A1 transcriptional regulation since we found putative insulin-response elements, FOXO1 binding sequences, in both rat and human CYP7A1 promoters. However, ectopic expression of FOXO1 increased the rat CYP7A1-, but mildly reduced human CYP7A1-promoter activities in a dose-dependent manner. Similarly to bile acids, insulin treatment increased small heterodimer partner (SHP) mRNA rapidly and transiently, leading to the suppression of CYP7A1 transcription in both human and rodents. Chromatin immunoprecipitation showed that FOXO1 directly bound to rat CYP1A1 promoter in the absence of insulin. FOXO1 binding to the rat promoter was diminished by insulin treatment as well as by expression of SHP. Our results suggest that the stimulation of insulin- signaling pathway of Akt-FOXO1 and SHP expression may regulate cholesterol/bile acid metabolisms in liver, linking carbohydrate and cholesterol metabolic pathways. A prolonged exposure of insulin in hyperinsulinemic insulin resistance or diabetic status represses CYP7A1 transcription and bile acid biosynthesis through SHP induction and FOXO1 inactivation, leading to impairment of the hepatic cholesterol/bile acid metabolisms.
Animals ; Bile Acids and Salts/metabolism ; Cholesterol/*metabolism ; Cholesterol 7-alpha-Hydroxylase/genetics/*metabolism ; Forkhead Transcription Factors/genetics/*metabolism ; Gene Expression Regulation/drug effects ; Glucose/*metabolism ; Hep G2 Cells ; Humans ; Insulin/pharmacology ; Lipid Metabolism/drug effects ; Liver/*metabolism/pathology ; Mice ; Mice, Inbred C57BL ; Mutagenesis, Site-Directed ; Nerve Tissue Proteins/genetics/*metabolism ; Protein Binding/drug effects/genetics ; Proto-Oncogene Proteins c-akt/metabolism ; Rats ; Receptors, Cytoplasmic and Nuclear/genetics/metabolism ; Sequence Deletion/genetics ; Signal Transduction/drug effects/genetics ; Transcriptional Activation/drug effects/genetics

OBJECTIVETo study the expressions of FXR, PPARa and Bile acid metabolism related genes in intrahepatic cholestasis of pregnant rats.

METHODS60 clean SD pregnant rats were selected and divided randomly into three groups. Since the 13th day of pregnancy rats in control group were injected subcutaneously with refined vegetable oil 2.0 mg/kg/d Rats in no-treated group were injected subcutaneously with the 17-a-ethynylestradiol (EE) 1.25 mg/kg/d until the 17th day. Those rat ih treated group were injected subcutaneously with the 17-a-ethynylestradiol (EE) 1.25 mg/kg/d until the 17th day and then were treated with fenofibrate for another four days until the 21th day. All rats were killed at the 21th day and livers were collected for study. The levels of serum TBA were examined by ELISA. The mRNA expressions of PPARa, FXR, CYP7A1, CYP27A1 and CYP8B1 were examined by real-time PCR. (1)

RESULTSThe levels of TBA were significantly higher in no-treated group (68.7+/-4.2)mumol/L and treated group (69.5+/-3.8)mumol/L compared with that of control group (26.6+/-2.3)mumol/L at the 17th day (P value is less than 0.05) and no difference found between treated and no-treated groups (P value is more than 0.05). The levels of TBA were higher in no-treated group (69.4+/-3.7)mumol/L and treated group (48.5+/-4.8)mumol/L as compared to control group (27.1+/-3.2)mumol/L at the 21th day (P value is less than 0.05). The lever of TBA was significantly lower in Treated group compared with No-treated group (P value is less than 0.05). (2) The mRNA expressions of CYP7A1, FXR, CYP27A1 and CYP8B1 increased in No-treated group (1.55+/-0.03, 1.75+/-0.02, 2.45+/-0.01, 2.15+/-0.01, respectively) and were all higher as compared to control group (0.75+/-0.02, 1.25+/-0.03, 0.65+/-0.03, 1.50+/-0.02, respectively) (P value is less than 0.05). However, the mRNA expression of PPARa decreased in No-treated group (0.85+/-0.02) compared with control group (1.45+/-0.02) (P value is less than 0.05). The mRNA expressions of CYP27A1, PPARa and CYP8B1 increased in treated group (1.25+/-0.01, 1.65+/-0.05, 1.65+/-0.02, respectively) and were all higher than that of control group (P value is less than 0.05).

CONCLUSIONAbnormal expressions of CYP7A1, FXR, CYP27A1, CYP8B1 and PPARa may play a role in pathogenesis of estrogen-induced intrahepatic cholestasis. Activator of PPARa may be used as therapeutical drug for ICP.

Animals ; Bile Acids and Salts ; metabolism ; Cholestasis, Intrahepatic ; chemically induced ; metabolism ; pathology ; Cholesterol 7-alpha-Hydroxylase ; metabolism ; Ethinyl Estradiol ; administration & dosage ; Female ; PPAR alpha ; metabolism ; Pregnancy ; Pregnancy Complications ; chemically induced ; metabolism ; pathology ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptors, Cytoplasmic and Nuclear ; genetics

OBJECTIVETo investigate the hypocholesterolemic activity of red yeast rice (RYR) and its underlying mechanism.

METHODSThree groups of hamsters were fed either the control diet or one of the two experimental diets containing by weight 0.1% RYR (0.1RYR) or 0.3% RYR (0.3RYR). Blood (0.5 mL) was collected from the retro-orbital sinus into a heparinized capillary tube at the end of week 0, 3, and 6. Plasma lipoproteins were measured using enzymatic kits, while fecal neutral and acidic sterols were quantified using a gas-liquid chromatography.

RESULTSPlasma total cholesterol was reduced by 12% in 0.1RYR group and by 18% in 0.3RYR group compared with the control value. Similarly, plasma triacylglycerol was decreased by 11% in 0.1RYR group and by 24% in 0.3RYR group. Western blotting analysis demonstrated that RYR had no effect on sterol regulatory element binding protein 2, liver X receptor, 3-hydroxy-3-methylglutary-CoA reductase, LDL receptor, and cholesterol-7alpha-hydroxylase. HPLC analysis confirmed that RYR contained 0.88% monacolin K. It was recently found that RYR supplementation increased excretion of fecal acidic sterols by 3-4 folds compared with the control value.

CONCLUSIONHypocholesterolemic activity of RYR is mediated at least partially by enhancement of acidic sterol excretion.

Animals ; Bile Acids and Salts ; secretion ; Biological Products ; pharmacology ; Blotting, Western ; Body Weight ; drug effects ; Cholesterol ; metabolism ; Cholesterol 7-alpha-Hydroxylase ; metabolism ; Cricetinae ; Dietary Supplements ; Feces ; chemistry ; Feeding Behavior ; drug effects ; Hydroxymethylglutaryl CoA Reductases ; metabolism ; Lipoproteins ; blood ; Liver ; enzymology ; Liver X Receptors ; Naphthalenes ; analysis ; Organ Size ; drug effects ; Orphan Nuclear Receptors ; metabolism ; Receptors, LDL ; metabolism ; Sterol Regulatory Element Binding Protein 2 ; metabolism ; Weight Gain ; drug effects

OBJECTIVETo investigate the expressions of small heterodimer partner (SHP) and target gene cholesterol-7-hydroxylase (CYP7A1) in livers of rats with intrahepatic cholestasis of pregnancy (ICP), and to study the mechanism of ICP.

METHODSThirty SD rats (pregnant for 15 days) were equally and randomly divided into two groups: an estradiol benzoate (EB) group and a normal saline (NS) group. Two ml blood was drawn from each rat before and on the 5th day after medicine administration to measure the levels of ALT, AST, ALP, TBA, TBIL, and DBIL. After delivery, the histopathological changes of the mother rat livers were studied. The mRNA and protein expressions of SHP and CYP7A1 in the livers were determined by RT-PCR and Western blot.

RESULTS(1) In the EB group, the serum levels of ALT, AST, ALP, TBA, TBil, and DBil after EB administration increased significantly (P less than 0.01), but there were no significant changes in the NS group (P more than 0.05); (2) Intrahepatic cholestasis appeared in the EB group, but not in the NS group; (3) The mRNA expressions of SHP and CYP7A1 were significantly higher in the EB group than in the NS group [(SHPmRNA: NS 0.365+/-0.0317 vs EB 0.4865+/-0.0237, P less than 0.01), (CYP7A1 mRNA: NS 0.3570+/-0.0175 vs EB 0.4802+/-0.0217, P less than 0.01)]; (4) The protein expressions of SHP and CYP7A1 were also higher in the EB group than that in the NS group [(SHP: NS 0.3762+/-0.0284 vs EB 0.5033+/-0.0274, P less than 0.01), (CYP7A1: NS 0.3570+/-0.0175 vs EB 0.4802+/-0.0217, P less than 0.01)].

CONCLUSIONEstrogen induces ICP in rats. The mRNA and protein expressions of SHP and CYP7A1 in livers of the ICP rats were increased, which causes more bile acids to be synthesized. This may be one of the mechanisms of ICP.

Animals ; Cholestasis, Intrahepatic ; chemically induced ; metabolism ; Cholesterol 7-alpha-Hydroxylase ; metabolism ; Estradiol ; analogs & derivatives ; pharmacology ; Female ; Liver ; metabolism ; Pregnancy ; Pregnancy Complications ; chemically induced ; metabolism ; Rats ; Receptors, Cytoplasmic and Nuclear ; metabolism