scholarly journals Genetic Polymorphisms in the TATA Box and Upstream Phenobarbital-Responsive Enhancer Module of the UGT1A1 Promoter Have Combined Effects on UDP-Glucuronosyltransferase 1A1 Transcription Mediated by Constitutive Androstane Receptor, Pregnane X Receptor, or Glucocorticoid Receptor in Human Liver

2009 ◽  
Vol 37 (9) ◽  
pp. 1978-1986 ◽  
Author(s):  
Ye Li ◽  
David Buckley ◽  
Shuang Wang ◽  
Curtis D. Klaassen ◽  
Xiao-bo Zhong
Keyword(s):  
Glucocorticoid Receptor ◽  
Genetic Polymorphisms ◽  
Human Liver ◽  
Constitutive Androstane Receptor ◽  
Pregnane X Receptor ◽  
Tata Box ◽  
Combined Effects ◽  
Udp Glucuronosyltransferase

Combining In Vivo and Organotypic In Vitro Approaches to Assess the Human Relevance of Basimglurant (RG7090), a Potential CAR Activator

2020 ◽  
Vol 176 (2) ◽  
pp. 329-342
Author(s):  
Ramona Nudischer ◽  
Kasper Renggli ◽  
Cristina Bertinetti-Lapatki ◽  
Jean-Christophe Hoflack ◽  
Nicholas Flint ◽  
...  
Keyword(s):  
Antisense Oligonucleotides ◽  
Human Liver ◽  
Constitutive Androstane Receptor ◽  
Pregnane X Receptor ◽  
Mrna Induction ◽  
Primary Mouse ◽  
Downstream Processes ◽  
Foci Of Altered Hepatocytes

Abstract Basimglurant (RG7090), a small molecule under development to treat certain forms of depression, demonstrated foci of altered hepatocytes in a long-term rodent-toxicity study. Additional evidence pointed toward the activation of the constitutive androstane receptor (CAR), an established promoter of nongenotoxic and rodent-specific hepatic tumors. This mode of action and the potential human relevance was explored in vivo using rodent and cynomolgus monkey models and in vitro using murine and human liver spheroids. Wild type (WT) and CAR/pregnane X receptor (PXR) knockout mice (CAR/PXR KO) were exposed to RG7090 for 8 consecutive days. Analysis of liver lysates revealed induction of Cyp2b mRNA and enzyme activity, a known activation marker of CAR, in WT but not in CAR/PXR KO animals. A series of proliferative genes were upregulated in WT mice only, and immunohistochemistry data showed increased cell proliferation exclusively in WT mice. In addition, primary mouse liver spheroids were challenged with RG7090 in the presence or absence of modified antisense oligonucleotides inhibiting CAR and/or PXR mRNA, showing a concentration-dependent Cyp2b mRNA induction only if CAR was not repressed. On the contrary, neither human liver spheroids nor cynomolgus monkeys exposed to RG7090 triggered CYP2B mRNA upregulation. Our data suggested RG7090 to be a rodent-specific CAR activator, and that CAR activation and its downstream processes were involved in the foci of altered hepatocytes formation detected in vivo. Furthermore, we demonstrated the potential of a new in vitro approach using liver spheroids and antisense oligonucleotides for CAR knockdown experiments, which could eventually replace in vivo investigations using CAR/PXR KO mice.

scholarly journals Regulation of CYP3A genes by glucocorticoids in human lung cells

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 173
Author(s):  
Jessica K Roberts ◽  
Chad D Moore ◽  
Erin G Romero ◽  
Robert M Ward ◽  
Garold S Yost ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Constitutive Androstane Receptor ◽  
A549 Cells ◽  
Persistent Asthma ◽  
Pregnane X Receptor ◽  
Lung Cells ◽  
Metabolic Clearance ◽  
Mrna Induction ◽  
Human Lung Cells ◽  
Tracheal Epithelial

Inhaled glucocorticoids are the first-line treatment for patients with persistent asthma.  However, approximately thirty percent of patients exhibit glucocorticoid insensitivity, which may involve excess metabolic clearance of the glucocorticoids by CYP3A enzymes in the lung.  CYP3A4, 3A5, and 3A7 enzymes metabolize glucocorticoids, which in turn induce CYP3A genes.  However, the mechanism of CYP3A5 mRNA regulation by glucocorticoids in lung cells has not been determined.  In hepatocytes, glucocorticoids bind to the glucocorticoid receptor (GR), which induces the expression of the constitutive androstane receptor or pregnane X receptor; both of which bind to the retinoid X receptor alpha, leading to the induction of CYP3A4, 3A5, and 3A7.  There is also evidence to suggest a direct induction of CYP3A5 by GR activation in liver cells. In this study, these pathways were evaluated as the mechanism for CYP3A5 mRNA induction by glucocorticoids in freshly isolated primary tracheal epithelial, adenocarcinomic human alveolar basal epithelial (A549), immortalized bronchial epithelial (BEAS-2B), primary normal human bronchial/tracheal epithelial (NHBE), primary small airway epithelial (SAEC), and primary lobar epithelial lung cells. In A549 cells, beclomethasone 17-monopropionate ([M1]) induced CYP3A5 mRNA through the glucocorticoid receptor. CYP3A5 mRNA induction by five different glucocorticoids was attenuated by inhibiting the glucocorticoid receptor using ketoconazole, and for beclomethasone dipropionate, using siRNA-mediated knock-down of the glucocorticoid receptor. The constitutive androstane receptor was not expressed in lung cells. SAEC cells, a primary lung cell line, expressed CYP3A5, but CYP3A5 mRNA was not induced by glucocorticoid treatment despite evaluating a multitude of cell culture conditions. None of the other lung cells expressed CYP3A4, 3A5 or 3A7 mRNA. These studies demonstrate that CYP3A5 mRNA is induced by glucocorticoids in A549 cells via the glucocorticoid receptor, but that additional undefined regulatory processes exist in primary lung cells.

scholarly journals Regulation of CYP3A genes by glucocorticoids in human lung cells

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 173 ◽  
Author(s):  
Jessica K Roberts ◽  
Chad D Moore ◽  
Erin G Romero ◽  
Robert M Ward ◽  
Garold S Yost ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Constitutive Androstane Receptor ◽  
A549 Cells ◽  
Persistent Asthma ◽  
Pregnane X Receptor ◽  
Lung Cells ◽  
Metabolic Clearance ◽  
Mrna Induction ◽  
Human Lung Cells ◽  
Tracheal Epithelial

Inhaled glucocorticoids are the first-line treatment for patients with persistent asthma.  However, approximately thirty percent of patients exhibit glucocorticoid insensitivity, which may involve excess metabolic clearance of the glucocorticoids by CYP3A enzymes in the lung.  CYP3A4, 3A5, and 3A7 enzymes metabolize glucocorticoids, which in turn induce CYP3A genes.  However, the mechanism of CYP3A5 mRNA regulation by glucocorticoids in lung cells has not been determined.  In hepatocytes, glucocorticoids bind to the glucocorticoid receptor (GR), which induces the expression of the constitutive androstane receptor or pregnane X receptor; both of which bind to the retinoid X receptor alpha, leading to the induction of CYP3A4, 3A5, and 3A7.  There is also evidence to suggest a direct induction of CYP3A5 by GR activation in liver cells. In this study, these pathways were evaluated as the mechanism for CYP3A5 mRNA induction by glucocorticoids in freshly isolated primary tracheal epithelial, adenocarcinomic human alveolar basal epithelial (A549), immortalized bronchial epithelial (BEAS-2B), primary normal human bronchial/tracheal epithelial (NHBE), primary small airway epithelial (SAEC), and primary lobar epithelial lung cells. In A549 cells, beclomethasone 17-monopropionate ([M1]) induced CYP3A5 mRNA through the glucocorticoid receptor. CYP3A5 mRNA induction by five different glucocorticoids was attenuated by inhibiting the glucocorticoid receptor using ketoconazole, and for beclomethasone dipropionate, using siRNA-mediated knock-down of the glucocorticoid receptor. The constitutive androstane receptor was not expressed in lung cells. SAEC cells, a primary lung cell line, expressed CYP3A5, but CYP3A5 mRNA was not induced by glucocorticoid treatment despite evaluating a multitude of cell culture conditions. None of the other lung cells expressed CYP3A4, 3A5 or 3A7 mRNA. These studies demonstrate that CYP3A5 mRNA is induced by glucocorticoids in A549 cells via the glucocorticoid receptor, but that additional undefined regulatory processes exist in primary lung cells.

Ketoconazole and Miconazole Are Antagonists of the Human Glucocorticoid Receptor: Consequences on the Expression and Function of the Constitutive Androstane Receptor and the Pregnane X Receptor

2006 ◽  
Vol 70 (1) ◽  
pp. 329-339 ◽  
Author(s):  
Cedric Duret ◽  
Martine Daujat-Chavanieu ◽  
Jean-Marc Pascussi ◽  
Lydiane Pichard-Garcia ◽  
Patrick Balaguer ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Constitutive Androstane Receptor ◽  
Pregnane X Receptor ◽  
And Function
Sign in / Sign up

Export Citation Format

Share Document