Aldosterone synthase activity in the Y-1 adrenal cell line

Routhier, M.Es-souni; Bournot, Paulette; Ramirez, Leyla C.

doi:10.1016/0960-0760(95)00009-o

Cited by 3 publications

(3 citation statements)

References 18 publications

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“…The molecular ion was at m/z 693, and distinctive fragment ions were formed at m/z 662 (M–31), m/z 572 (M–31–90), m/z 482 (M–31–90–90), and m/z 392 (M–31–90–90–90). The base peak is the side‐chain‐derived ion at m/z 205, characteristic of steroids containing hydroxyl groups at C20 and C21 . The presence of fragment ions at m/z 163 and 189 pointed towards the presence of a methyl group at C6.…”

Section: Results and Discusionmentioning

confidence: 99%

“…The base peak is the side-chain-derived ion at m/z 205, characteristic of steroids containing hydroxyl groups at C20 and C21. [23] The presence of fragment ions at m/z 163 and 189 pointed towards the presence of a methyl group at C6. Previous GC/MS studies obtained similar results and it was concluded that those peaks corresponded to the 20-hydroxy metabolites.…”

Section: M1mentioning

confidence: 99%

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Using complementary mass spectrometric approaches for the determination of methylprednisolone metabolites in human urine

Pozo

Marcos

Matabosch

et al. 2012

Rapid Comm Mass Spectrometry

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Section: Results and Discusionmentioning

confidence: 99%

Section: M1mentioning

confidence: 99%

Using complementary mass spectrometric approaches for the determination of methylprednisolone metabolites in human urine

Pozo

Marcos

Matabosch

et al. 2012

Rapid Comm Mass Spectrometry

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“…H295R cells express all key steroidogenic enzymes and produce all three classes of steroid hormones. , In this study, we report an analysis of the toxicity and metabolism of BMS-A in rodents and in vitro adrenal cell lines, including a comparison of the toxicity of BMS-A in human (H295R) and mouse (Y-1) adrenocortical cell lines. The human H295R cell line has been widely used to study adrenocortical functional regulation of steroidogenesis and screening for enzyme inhibitor. − Mouse Y-1 cells express the functional enzymes implicated in both the glucocorticoid and mineralocorticoid pathways …”

Section: Introductionmentioning

confidence: 99%

Cytochrome P450 11A1 Bioactivation of a Kinase Inhibitor in Rats: Use of Radioprofiling, Modulation of Metabolism, and Adrenocortical Cell Lines to Evaluate Adrenal Toxicity

Zhang

Flint

Wang

et al. 2012

Chem. Res. Toxicol.

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A drug candidate, BMS-A ((N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)-3-fluorophenyl)-1-(4-fluorophenyl) 2-oxo-1,2-dihydropyridine- 3-carboxamide)), was associated with dose- and time-dependent vacuolar degeneration and necrosis of the adrenal cortex following oral administration to rats. Pretreatment with 1-aminobenzotriazole (ABT), a nonspecific P450 inhibitor, ameliorated the toxicity. In vivo and in vitro systems, including adrenal cortex-derived cell lines, were used to study the mechanism responsible for the observed toxicity. Following an oral dose of the C-14 labeled compound, two hydroxylated metabolites of the parent (M2 and M3) were identified as prominent species found only in adrenal glands and testes, two steroidogenic organs. In addition, a high level of radioactivity was covalently bound to adrenal tissue proteins, 40% of which was localized in the mitochondrial fraction. ABT pretreatment reduced localization of radioactivity in the adrenal gland. Low levels of radioactivity bound to proteins were also observed in testes. Both M3 and covalent binding to proteins were found in incubations with mitochondrial fraction isolated from adrenal tissue in the presence of NADPH. In vitro formation of M3 and covalent binding to proteins were not affected by addition of GSH or a CYP11B1/2 inhibitor, metyrapone (MTY), but were inhibited by ketoconazole (KTZ) and a CYP11A1 inhibitor, R-(+)-aminoglutethimide (R-AGT). BMS-A induced apoptosis in a mouse adrenocortical cell line (Y-1) but not in a human cell line (H295R). Metabolite M3 and covalent binding to proteins were also produced in Y-1 and to a lesser extent in H295R cells. The cell toxicity, formation of M3, and covalent binding to proteins were all diminished by R-AGT but not by MTY. These results are consistent with a CYP11A1-mediated bioactivation to generate a reactive species, covalent binding to proteins, and subsequently rat adrenal toxicity. The thorough understanding of the metabolism-dependent adrenal toxicity was useful to evaluate cross-species adrenal toxicity potential of this compound and related analogues.

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Angiotensin II and Potassium Regulate Human CYP11B2 Transcription through Common cis-Elements

Clyne¹,

Zhang²,

Slutsker

et al. 1997

Molecular Endocrinology

157

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Aldosterone synthase is a mitochondrial enzyme that catalyzes the conversion of 11-deoxycorticosterone to the potent mineralocorticoid aldosterone. The gene encoding aldosterone synthase, CYP11B2, is expressed in the zona glomerulosa of the adrenal cortex. Although the major physiological regulators of aldosterone production are angiotensin II (ANG II) and potassium (K+), the mechanisms by which these compounds regulate CYP11B2 transcription are unknown. Therefore we analyzed the human CYP11B2 5'-flanking region using a transient transfection expression system in the H295R human adrenocortical cell line. ANG II and K+ increased expression of a luciferase reporter construct containing 2015 bp of human CYP11B2 5'-flanking DNA. This response was mimicked by treatment with the calcium channel activator BAYK8644, whereas activation of the protein kinase C pathway with 12-o-tetradecanoylphorbol-13-acetate had no effect. Reporter gene activity was also increased after activation of cAMP-dependent pathways by (Bu)2cAMP. Deletion, mutation, and deoxyribonuclease I footprinting analyses of the CYP11B2 5'-flanking region identified two distinct elements at positions -71/-64 (TGACGTGA) and -129/-114 (CTCCAGCCTTGACCTT) that were both required for full basal reporter gene activity and for maximal induction by either cAMP or calcium-signaling pathways. The -71/-64 element, which resembles a consensus cAMP response element (CRE), bound CRE-binding proteins from H295R cell nuclear extracts as determined by electrophoretic mobility shift analysis. Analysis of the -129/-114 element using electrophoretic mobility shift analysis demonstrated binding of the orphan nuclear receptors steroidogenic factor 1 and chicken ovalbumin upstream promoter transcription factor. These data demonstrate that ANG II, K+, and cAMP-signaling pathways utilize the same SF-1 and CRE-like cis-elements to regulate human CYP11B2 expression.

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Aldosterone synthase activity in the Y-1 adrenal cell line

Cited by 3 publications

References 18 publications

Using complementary mass spectrometric approaches for the determination of methylprednisolone metabolites in human urine

Using complementary mass spectrometric approaches for the determination of methylprednisolone metabolites in human urine

Cytochrome P450 11A1 Bioactivation of a Kinase Inhibitor in Rats: Use of Radioprofiling, Modulation of Metabolism, and Adrenocortical Cell Lines to Evaluate Adrenal Toxicity

Angiotensin II and Potassium Regulate Human CYP11B2 Transcription through Common cis-Elements

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