Hypolipidemic effect of SIPI-7623, a derivative of an extract from oriental wormwood, through farnesoid X receptor antagonism / 中国天然药物

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.

Hypolipidemic effect of SIPI-7623, a derivative of an extract from oriental wormwood, through farnesoid X receptor antagonism / 中国天然药物

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.

The genetic polymorphism of CYP7A1 in Fujian Han HBV infected patients / 中华检验医学杂志

Objective The study aims to investigate the associationbetweencholesterol 7α-hydroxylase (CYP7A1) gene polymorphism and different clinical outcomes after Hepatitis B virus (HBV)infection in Fujian Han population and lay a foundation for understanding the mechanisms of genesis anddevelopment of HBV-related diseases.Methods Case-control study was conducted.586 patients of HBVpersistent infection without antiviral therapy and 225 HBV rehabilitation patients (35-55 years old) werecollected from May 2015 to June 2016 in the Liverish Center of First Clinical College of Fujian MedicalUniversity.The group of HBV persistent infection without antiviral therapy included 246 patients with chronichepatitis B, 177 patients with hepatitis B-related cirrhosis, and 163 patients with hepatitis B-related liver cancer.The rs3824260, rs4738687and rs8192871 loci of CYP7A1 gene were detected by improved multipleligase detection reaction (iMLDR).Logistic regression analysis and chi-square test were used to analyze thegenotyping results.Results Three SNPs ( single nucleotide polymorphisms ) of CYP7A1 gene wereselected and compared between HBV persistent infection group and HBV rehabilitation group and betweenchronic hepatitis B subgroup, liver cirrhosis subgroup and liver cancer subgroup.After adjustment for factorsincluding age andgender, there was no significant difference in the distribution of rs3824260 genotype amongthe groups(χ2 =1.565,P =0.459), however,the frequency of allele C in HBV rehabilitation group wassignificantly higher than in HBV persistent in fectiongroup for men (χ2 =4.365,P =0.037), whereas thefrequency of rs3824260 CC and CT was more likely to be observed in liver cancer group than in non -livercancer group (chronic hepatitis B subgroup and liver cirrhosis subgroup ) for women (χ2 =5.768,P =0.012;χ2 =10.130,P =0.001).The frequency of rs4738687 GG genotype was more likely to be observed innon-liver cancer group than in liver cancer group (χ2 =4.403,P =0.041;χ2 =6.940,P =0.009).Theresults of gender stratification showed that there were significant differences in the distribution of rs 4738687among the HBV persistent infection groups for men (χ2 =10.697,P =0.030), however, there was nosignificant difference in the distribution of rs4738687 among the HBV persistent infection groups for women(χ2 =4.627,P =0.329), and there was no significant difference in the distribution of genotype frequencyand allele frequency among all groups(χ2 =0.489,P =0.792).There was no significant difference after sexstratification either (χ2 =1.282, P =0.526;χ2 =1.565,P =0.465) .Conclusions These findingssuggested that CYP7A1 gene polymorphism was related todifferent clinical outcomes in Fujian Hanpopulation.The rs3824260 mutation had a certain gender preference and the mutation allele was detected ina higher proportion in male patients.Male HBV patients with rs3824260 C allele had more chance ofswitching to rehabilitation.The rs4738687 was likely to be related to the occurrence of liver cancer in FujianHan population, and GG genotype may delay the occurrence and development of liver cancer especially in themale group.The rs8192871 was not found to be related to the different clinical outcomes of HBV infection.

Effects of Ursolic Acid on Cholesterol Metabolism in Hepatic Cells / 医药导报

Objective To explore the effects and mechanism of ursolic acid ( UA) on cholesterol metabolism in human hepatocellular carcinoma HepG2 and mouse hepatocyte AML-12. Methods HepG2 and AML-12 cells were treated with different concentrations of UA (0,10,20,40 μmol·L-1)for 24 h, then the mRNA and protein expression of cholesterol 7alpha-hydroxylase (CYP7A1) and intracellular cholesterol level was detected by RT-PCR、Western blotting and enzymatic method, respectively. Results Compared with 0 μmol·L-1 UA, 20 μmol·L-1 and 40 μmol·L-1 UA significantly increased the expressions of CYP7A1 mRNA and protein(P<0. 05), and decreased intracellular cholesterol level in HepG2 and AML-12 cells (P<0. 05). Conclusion A certain concentration of UA can reduce the level of cholesterol in HepG2 and AML-12 cells. CYP7A1 may be involved in the regulation process.

Effects of cholesterol-lowering probiotics on the metabolism of bile acid in a rat model of non-alcoholic fatty liver disease and the possible mechanism / 中华微生物学和免疫学杂志

Objective To investigate the effects of two cholesterol-lowering probiotics, DM9054 (Lac-tobacillus Rhamnosus GG, LGG) in combination with 86066 (Lactobacillus plantarum WCFS1, LP), on the metabolism of bile acid via a rat model of non-alcoholic fatty liver disease (NAFLD) and the possible mecha-nism. Methods Twenty-one SD male rats were randomly divided into three groups including control group, NAFLD model group and probiotics intervention group. Rats in the control group received normal diet. The rat model of NAFLD was established by feeding rats with chronic high fat diet (45% of calories derived from fat di-et) for 20 weeks. Rats in the probiotics intervention group were given high fat diet together with cholesterol-low-ering probiotics through oral gavage. General indexes of each group including body weight and the levels of tri-glyceride, cholesterol and CK18-M30 in serums samples were detected. The expression of cholesterol 7-alpha hydroxy-lase (CYP7A1), fibroblast growth factor receptor 4 (FGFR4), farnesoid X receptor (FXR), fibroblast grwoth factor 15 (FGF15) and apical sodium-dependent bile acid transparter(ASBT) at mRNA level were de-tected by using real-time polymerase chain reaction (real-time PCR). Western blot assay was used to detect the protein expression of CYP7A1, FXR in liver tissues and ASBT in ileum tissues. The expression of FXR in liver and ileum tissues were analyzed by immunohistochemistry. Results Rats with NAFLD showed loss of body weight and decreased levels of the serological markers after treating with the probiotics (P0. 05). Conclusion Probiotics intervention might up-regulate the expression of CYP7A1 by suppressing the FXR path-way in liver tissues and inhibiting the expression of ASBT in ileum tissues. Treating NAFLD rats with cholester-ol-lowering probiotics could activate the FXR-FGF15 pathway in ileum tissues and enhance the metabolism of bile acid, which contributed to the alleviation of NAFLD.

Insulin-dependent suppression of cholesterol 7alpha-hydroxlase is a possible link between glucose and cholesterol metabolisms

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.

Insulin-dependent suppression of cholesterol 7alpha-hydroxlase is a possible link between glucose and cholesterol metabolisms

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.

Changes of cholesterol 7alpha-hydroxylase, farnesoid X receptor, and small heterodimer partner expression in liver tissues of rats with obstructive cholestasis / 第二军医大学学报

Objective: To investigate the changes of cholesterol 7alpha- hydroxylase(CYP7A1) ,farnesoid X receptor(FXR), and small heterodimer partner (SHP) expression in liver tissues of bile duct ligated (BDL) rats,and to analyze the relationship between their expression. Methods: Obstructive cholestasis rat model was induced by bile duct ligation,and rats were sacrificed on day 1,3,and 14 after operation. The hepatic tissues were collected and the total mRNA was extracted. The CYP7A1 mRNA expression was determined by real-time RT-PCR. The protein expression of FXR and SHP in the nuclei was determined by Western blotting analysis. Results: Compared with sham-operated group, experimental obstructive cholestasis group had significantly enhanced CYP7A1 mRNA expression and decreased FXR,SHP expression(P<0. 001,P<0. 05). Conclusion: The up-regulation of CYP7A1 may be associated with the down-regulation of FXR and SHP.

Effect of MCT on CYP7A1 gene expression and cholesterol metabolism in mice / 中国病理生理杂志

AIM: To explore the effect and the corresponding mechanism of medium chain triglyceride (MCT) on CYP7A1 gene expression in mice. METHODS: C57BL/6J mice (15/group) were respectively received mash as AIN-93G formula (basic control BC), or 1% cholesterol supplemented AIN-93G formula (Chol), or 1% cholesterol and 14% long chain triglyceride (LCT) rich in myristic acid supplemented AIN-93G formula (Chol+LCT), or 1%cholesterol and 14% MCT (caprylic acid/capric acid: 3/1) supplemented AIN-93G formula (Chol+MCT) for 6 weeks. The change of serum total cholesterol (TC), the content of cholesterol in liver, the bile acid pool of mice and the expression of cholesterol 7-hydroxylase (CYP7A 1) gene were investigated. RESULTS: Compared to mice fed Chol diet, the mice fed Chol+MCT diet had the lower serum TC (P