Unexpected contribution of cytochrome P450 enzymes CYP11B2 and CYP21, as well as CYP3A4 in xenobiotic androgen elimination – Insights from metandienone metabolism

Parr, Maria Kristina; Zöllner, Andy; Fußhöller, Gregor; Opfermann, Georg; Schlörer, Nils; Zorio, Mirela; Bureik, Matthias; Schänzer, Wilhelm

doi:10.1016/j.toxlet.2012.07.020

Cited by 36 publications

(36 citation statements)

References 30 publications

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“…Pck1, Phosphoenolpyruvate carboxykinase 1 (soluble), is a main control point for the regulation of gluconeogenesis [102]. Cyp11b2 (cytochrome P450, family 11, subfamily B, polypeptide 2) and Cyp7a1 (cytochrome P450, family 7, subfamily A, polypeptide 1) belong to the cytochrome P450 protein family and these monooxygenases catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids, that are related to cellular oxidative stress [103], [104].…”

Section: Discussionmentioning

confidence: 99%

Genome-Wide Identification of Molecular Pathways and Biomarkers in Response to Arsenic Exposure in Zebrafish Liver

Lam

Shen

et al. 2013

PLoS ONE

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Inorganic arsenic is a worldwide metalloid pollutant in environment. Although extensive studies on arsenic-induced toxicity have been conducted using in vivo and in vitro models, the exact molecular mechanism of arsenate toxicity remains elusive. Here, the RNA-SAGE (serial analysis of gene expression) sequencing technology was used to analyse hepatic response to arsenic exposure at the transcriptome level. Based on more than 12 million SAGE tags mapped to zebrafish genes, 1,444 differentially expressed genes (750 up-regulated and 694 down-regulated) were identified from a relatively abundant transcripts (>10 TPM [transcripts per million]) based on minimal two-fold change. By gene ontology analyses, these differentially expressed genes were significantly enriched in several major biological processes including oxidation reduction, translation, iron ion transport, cell redox, homeostasis, etc. Accordingly, the main pathways disturbed include metabolic pathways, proteasome, oxidative phosphorylation, cancer, etc. Ingenity Pathway Analysis further revealed a network with four important upstream factors or hub genes, including Jun, Kras, APoE and Nr2f2. The network indicated apparent molecular events involved in oxidative stress, carcinogenesis, and metabolism. In order to identify potential biomarker genes for arsenic exposure, 27 out of 29 up-regulated transcripts were validated by RT-qPCR analysis in pooled RNA samples. Among these, 14 transcripts were further confirmed for up-regulation by a lower dosage of arsenic in majority of individual zebrafish. Finally, at least four of these genes, frh3 (ferrintin H3), mgst1 (microsomal glutathione S-transferase-like), cmbl (carboxymethylenebutenolidase homolog) and slc40a1 (solute carrier family 40 [iron-regulated transporter], member 1) could be confirmed in individual medaka fish similarly treated by arsenic; thus, these four genes might be robust arsenic biomarkers across species. Thus, our work represents the first comprehensive investigation of molecular mechanism of asenic toxicity and genome-wide search for potential biomarkers for arsenic exposure.

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Section: Discussionmentioning

confidence: 99%

Genome-Wide Identification of Molecular Pathways and Biomarkers in Response to Arsenic Exposure in Zebrafish Liver

Lam

Shen

et al. 2013

PLoS ONE

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“…In summary, these results clearly demonstrated that OT is the second xenobiotic steroid whose metabolism by steroidogenic P450 enzymes has been observed, in addition to metandienone (Parr et al, 2012). Our detailed in vitro studies hint at a potentially systematic contribution of human steroidogenic P450 enzymes to the metabolism of xenobiotics, which suggests their consideration as drug-metabolizing enzymes during drug design and toxicity evaluation.…”

Section: Discussionmentioning

confidence: 52%

“…However, the 3keto-Δ4 motif, which was already supposed to be conserved among all CYP11B substrates using endogenous steroids (Strushkevich et al, 2013), is preserved and seems to be sufficient for proper binding. Interestingly, CYP11B2 metabolism of metandienone, which is structurally identical to OT except for the 4-chloro group, comprises only monohydroxylations in positions 11b and 18 (Parr et al, 2012). Compared with the metabolites formed from OT by CYP11B2, the differences between OT and metandienone metabolism lead to the suggestion that the C 4 substitution of OT determines the processivity of the reaction.…”

Section: Discussionmentioning

confidence: 99%

“…CYP21A2 and both CYP11B isoforms were shown to be involved in the metabolism of the synthetic anabolic androgenic steroid (AAS) metandienone (Zöllner et al, 2010;Parr et al, 2012) and there are even indications for the contribution of CYP11B1 to the bioactivation of the nonsteroidal environmental pollutant 3-methylsulfonyl-2,2-bis(4-chlorophenyl)-1,1-dichloroethene (Lund and Lund, 1995).…”

Section: Introductionmentioning

confidence: 99%

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Metabolism of Oral Turinabol by Human Steroid Hormone-Synthesizing Cytochrome P450 Enzymes

Schiffer

Brixius‐Anderko

Hannemann

et al. 2015

Drug Metabolism and Disposition

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The human mitochondrial cytochrome P450 enzymes CYP11A1, CYP11B1, and CYP11B2 are involved in the biosynthesis of steroid hormones. CYP11A1 catalyzes the side-chain cleavage of cholesterol, and CYP11B1 and CYP11B2 catalyze the final steps in the biosynthesis of gluco-and mineralocorticoids, respectively. This study reveals their additional capability to metabolize the xenobiotic steroid oral turinabol (OT; 4-chlor-17b-hydroxy-17a-methylandrosta-1,4-dien-3-on), which is a common doping agent. By contrast, microsomal steroid hydroxylases did not convert OT. Spectroscopic binding assays revealed dissociation constants of 17.7 mM and 5.4 mM for CYP11B1 and CYP11B2, respectively, whereas no observable binding spectra emerged for CYP11A1. Catalytic efficiencies of OT conversion were determined to be 46 min 21 mM 21 for CYP11A1, 741 min 21 mM 21 for CYP11B1, and 3338 min 21 mM 21 for CYP11B2, which is in the same order of magnitude as for the natural substrates but shows a preference of CYP11B2 for OT conversion. Products of OT metabolism by the CYP11B subfamily members were produced at a milligram scale with a recombinant Escherichia coli-based whole-cell system. They were identified by nuclear magnetic resonance spectroscopy to be 11b-OH-OT for both CYP11B isoforms, whereby CYP11B2 additionally formed 11b,18-diOH-OT and 11b-OH-OT-18-al, which rearranges to its tautomeric form 11b,18-expoxy-18-OH-OT. CYP11A1 produces six metabolites, which are proposed to include 2-OH-OT, 16-OH-OT, and 2,16-diOH-OT based on liquid chromatography-tandem mass spectrometry analyses. All three enzymes are shown to be inhibited by OT in their natural function. The extent of inhibition thereby depends on the affinity of the enzyme for OT and the strongest effect was demonstrated for CYP11B2. These findings suggest that steroidogenic cytochrome P450 enzymes can contribute to drug metabolism and should be considered in drug design and toxicity studies.

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“…Structure of the D‐ring in steroids 3 – 6 is unique due to the configuration of its quaternary C17 stereocenter, which in combination with an endocyclic C13−C14 double bond makes this fragment a challenging target for chemical synthesis. This fact is particularly impressive, since epimeic at C17 D ‐fragment 7 as well as other 18‐nor‐13‐ene steroids 8 – 12 bearing a nonhydroxylated 17β‐methyl group are readily available by a stereospecific Wagner–Meerwein shift of the 18‐methyl group in the cationic intermediates 13 (Scheme ). The only known routes to steroids 16 have been based on a biotechnological oxidation of the rearranged intermediates 8 (Scheme ) .…”

Section: Methodsmentioning

confidence: 99%

C−H Acetoxylation‐Based Chemical Synthesis of 17 β‐Hydroxymethyl‐17 α‐methyl‐18‐norandrost‐13‐ene Steroids

Hurski

Barysevich

Dalidovich

et al. 2016

Chemistry A European J

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Palladium-catalyzed C-H acetoxylation has been proposed as a key transformation in the first chemical synthesis of steroids bearing a unique 17β-hydroxymethyl-17α-methyl-18-nor-13-ene D-fragment. This C-H functionalization step was crucial for inverting the configuration at the quaternary stereocenter of a readily available synthetic intermediate. The developed approach was applied to prepare the metandienone metabolite needed as a reference substance in anti-doping analysis to control the abuse of this androgenic anabolic steroid.

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Unexpected contribution of cytochrome P450 enzymes CYP11B2 and CYP21, as well as CYP3A4 in xenobiotic androgen elimination – Insights from metandienone metabolism

Cited by 36 publications

References 30 publications

Genome-Wide Identification of Molecular Pathways and Biomarkers in Response to Arsenic Exposure in Zebrafish Liver

Genome-Wide Identification of Molecular Pathways and Biomarkers in Response to Arsenic Exposure in Zebrafish Liver

Metabolism of Oral Turinabol by Human Steroid Hormone-Synthesizing Cytochrome P450 Enzymes

C−H Acetoxylation‐Based Chemical Synthesis of 17 β‐Hydroxymethyl‐17 α‐methyl‐18‐norandrost‐13‐ene Steroids

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