The present study examines the feedback control governing human cholesterol 7 alpha-hydroxylase mRNA expression in the human hepatoblastoma cell line, Hep G2. Glycochenodeoxycholate (GCDC) and glycodeoxycholate, hydrophobic bile salts, decreased…
Bile acids concentration in liver is tightly regulated to prevent cell damage. Previous studies have demonstrated that deregulation of bile acid homeostasis can lead to cholestatic liver disease. Recently, we have shown that ER-bound transcription…
Hepatic gluconeogenesis is tightly balanced by opposing stimulatory (glucagon) and inhibitory (insulin) signaling pathways. Hepatocyte growth factor (HGF) is a pleiotropic growth factor that mediates diverse biological processes. In this study, we…
The gene for cholesterol 7 alpha-hydroxylase (CYP7A1) contains a sequence at nt -149 to -118 that was found to play a large role in determining the overall transcriptional activity and regulation of the promoter. Hepatocyte nuclear factor 4 (HNF4)…
In primary cultures of rat hepatocytes, transcription of the cholesterol 7 alpha-hydroxylase gene is induced synergistically by glucocorticoid and thyroid hormones. The objective of the present study was to evaluate the role of glucocorticoid and…
In primary cultures of adult rat hepatocytes the level of cholesterol 7-alpha-hydroxylase steady-state mRNA markedly decreased by 72 h. However, the addition of L-thyroxine (T4) and dexamethasone synergistically returned cholesterol…
Vitamin D receptor (VDR) mediates vitamin D signaling involved in bone metabolism, cellular growth and differentiation, cardiovascular function, and bile acid regulation. Mice with an intestine-specific disruption of VDR (Vdr(Delta IEpC)) have…
Activation of farnesoid X receptor (Fxr, Nr1h4) is a major mechanism in suppressing bile-acid synthesis by reducing the expression levels of genes encoding key bile-acid synthetic enzymes (e.g., cytochrome P450 [CYP]7A1/Cyp7a1 and CYP8B1/Cyp8b1).…
Sterol 12alpha-hydroxylase (CYP8B1) is an obligatory enzyme for the synthesis of cholic acid and regulation of liver bile acid synthesis and intestine cholesterol absorption. The present study evaluates the roles for sterol regulatory element binding…
Hydrophobic bile acids strongly repressed transcription of the human cholesterol 7 alpha -hydroxylase gene (CYP7A1) in the bile acid biosynthetic pathway in the Ever. Farnesoid X receptor (FXR) repressed CYP7A1/Luc reporter activity in a transfection…
The sterol 12alpha-hydroxylase (CYP8B1) is a key enzyme of the bile acid biosynthetic pathway. It regulates the composition of bile acids in bile, i.e. ratio between cholic acid (CA) and chenodeoxycholic acid (CDCA). In similarity with cholesterol…
Growth hormone (GH) is a key metabolic regulator mediating glucose and lipid metabolism. Ataxia telangiectasia mutated (ATM) is a member of the phosphatidylinositol 3-kinase superfamily and regulates cell cycle progression. The orphan nuclear…
The cholesterol 7 alpha-hydroxylase gene (CYP7A) is transcriptionally regulated by a number of factors, including hormones, bile acids, and diurnal rhythm. Previous studies have identified a region from nucleotides (nt) -74 to -55 of the rat CYP7A…
