Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Original Article
  • Published:

Gene copy number variation analysis reveals dosage-insensitive expression of CYP2E1

Abstract

Gene copy number variants (CNVs) of CYP2E1 have been described but not functionally characterized. Here we investigated effects of CNVs on hepatic and lymphoblastoid CYP2E1 expression. Using available single-nuleotide polymorphism microarray data and quantitative PCR, CYP2E1 gene duplication and deletion carriers were identified. CYP2E1 mRNA, protein and enzyme activity (chlorzoxazone-6-hydroxylation) phenotypes of CYP2E1 were not associated with gene copy number. Analysis of gene expression in lymphoblastoid cell lines in relation to CNV confirmed this finding in an extrahepatic tissue and for other ethnicities. Further analyses identified a linked haplotype cluster with possible influence on gene expression. In summary, our data suggest a homeostatic, gene dosage-insensitive regulation of CYP2E1 expression by unknown gene dosage compensation mechanisms. This is in striking contrast to well-known structural variations of CYP2A6 and CYP2D6 that have a strong impact on expression and activity. These findings are important in the context of pharmacogenetic prediction.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5

Similar content being viewed by others

References

  1. Butler MW, Hackett NR, Salit J, Strulovici-Barel Y, Omberg L, Mezey J et al. Glutathione S-transferase copy number variation alters lung gene expression. Eur Respir J 2011; 38: 15–28.

    Article  CAS  Google Scholar 

  2. Hebbring SJ, Adjei AA, Baer JL, Jenkins GD, Zhang J, Cunningham JM et al. Human SULT1A1 gene: copy number differences and functional implications. Hum Mol Genet 2007; 16: 463–470.

    Article  CAS  Google Scholar 

  3. Mwenifumbo JC, Tyndale RF . Genetic variability in CYP2A6 and the pharmacokinetics of nicotine. Pharmacogenomics 2007; 8: 1385–1402.

    Article  CAS  Google Scholar 

  4. Schaeffeler E, Schwab M, Eichelbaum M, Zanger UM . CYP2D6 genotyping strategy based on gene copy number determination by TaqMan real-time PCR. Hum Mutat 2003; 22: 476–485.

    Article  CAS  Google Scholar 

  5. Ingelman-Sundberg M, Sim SC, Gomez A, Rodriguez-Antona C . Influence of cytochrome P450 polymorphisms on drug therapies: pharmacogenetic, pharmacoepigenetic and clinical aspects. Pharmacol Ther 2007; 116: 496–526.

    Article  CAS  Google Scholar 

  6. Madadi P, Koren G, Cairns J, Chitayat D, Gaedigk A, Leeder JS et al. Safety of codeine during breastfeeding: fatal morphine poisoning in the breastfed neonate of a mother prescribed codeine. Can Fam Physician 2007; 53: 33–35.

    PubMed  PubMed Central  Google Scholar 

  7. Zanger UM, Schwab M . Cytochrome P450 enzymes in drug metabolism: regulation of gene expression, enzyme activities, and impact of genetic variation. Pharmacol Ther 2013; 138: 103–141.

    Article  CAS  Google Scholar 

  8. Martis S, Mei H, Vijzelaar R, Edelmann L, Desnick RJ, Scott SA . Multi-ethnic cytochrome-P450 copy number profiling: novel pharmacogenetic alleles and mechanism of copy number variation formation. Pharmacogenomics J 2013; 13: 558–566.

    Article  CAS  Google Scholar 

  9. MacDonald JR, Ziman R, Yuen RKC, Feuk L, Scherer SW . The database of genomic variants: a curated collection of structural variation in the human genome. Nucleic Acids Res 2014; 42: D986–D992.

    Article  CAS  Google Scholar 

  10. Bolt HM, Roos PH, Thier R . The cytochrome P-450 isoenzyme CYP2E1 in the biological processing of industrial chemicals: consequences for occupational and environmental medicine. Int Arch Occup Environ Health 2003; 76: 174–185.

    CAS  PubMed  Google Scholar 

  11. Koop DR, Casazza JP . Identification of ethanol-inducible P-450 isozyme 3a as the acetone and acetol monooxygenase of rabbit microsomes. J Biol Chem 1985; 260: 13607–13612.

    CAS  PubMed  Google Scholar 

  12. Gonzalez FJ . The 2006 Bernard B. Brodie Award Lecture. Cyp2e1. Drug Metab Dispos 2007; 35: 1–8.

    Article  CAS  Google Scholar 

  13. Cederbaum AI . Hepatoprotective effects of S-adenosyl-L-methionine against alcohol- and cytochrome P450 2E1-induced liver injury. World J Gastroenterol 2010; 16: 1366–1376.

    Article  CAS  Google Scholar 

  14. Ekström G, Ingelman-Sundberg M . Rat liver microsomal NADPH-supported oxidase activity and lipid peroxidation dependent on ethanol-inducible cytochrome P-450 (P-450IIE1). Biochem Pharmacol 1989; 38: 1313–1319.

    Article  Google Scholar 

  15. Caro AA, Cederbaum AI . Oxidative stress, toxicology, and pharmacology of CYP2E1. Annu Rev Pharmacol Toxicol 2004; 44: 27–42.

    Article  CAS  Google Scholar 

  16. Daly AK . Relevance of CYP2E1 to non-alcoholic fatty liver disease. Subcell Biochem 2013; 67: 165–175.

    Article  CAS  Google Scholar 

  17. Dey A . Cytochrome P450 2E1: its clinical aspects and a brief perspective on the current research scenario. Subcell Biochem 2013; 67: 1–104.

    Article  CAS  Google Scholar 

  18. Ingelman-Sundberg M, Johansson I, Yin H, Terelius Y, Eliasson E, Clot P et al. Ethanol-inducible cytochrome P4502E1: genetic polymorphism, regulation, and possible role in the etiology of alcohol-induced liver disease. Alcohol 1993; 10: 447–452.

    Article  CAS  Google Scholar 

  19. Mohri T, Nakajima M, Fukami T, Takamiya M, Aoki Y, Yokoi T . Human CYP2E1 is regulated by miR-378. Biochem Pharmacol 2010; 79: 1045–1052.

    Article  CAS  Google Scholar 

  20. Achour B, Barber J, Rostami-Hodjegan A . Expression of hepatic drug-metabolizing cytochrome p450 enzymes and their intercorrelations: a meta-analysis. Drug Metab Dispos Biol Fate Chem 2014; 42: 1349–1356.

    Article  Google Scholar 

  21. Ferguson CS, Tyndale RF . Cytochrome P450 enzymes in the brain: emerging evidence of biological significance. Trends Pharmacol Sci 2011; 32: 708–714.

    Article  CAS  Google Scholar 

  22. Thelen K, Dressman JB . Cytochrome P450-mediated metabolism in the human gut wall. J Pharm Pharmacol 2009; 61: 541–558.

    Article  CAS  Google Scholar 

  23. Woodcroft KJ, Hafner MS, Novak RF . Insulin signaling in the transcriptional and posttranscriptional regulation of CYP2E1 expression. Hepatology 2002; 35: 263–273.

    Article  CAS  Google Scholar 

  24. Wang Z, Hall SD, Maya JF, Li L, Asghar A, Gorski JC . Diabetes mellitus increases the in vivo activity of cytochrome P450 2E1 in humans. Br J Clin Pharmacol 2003; 55: 77–85.

    Article  CAS  Google Scholar 

  25. Cheng J, Chen C, Kristopher KW, Manna SK, Scerba M, Friedman FK et al. Identification of 2-piperidone as a biomarker of CYP2E1 activity through metabolomic phenotyping. Toxicol Sci 2013; 135: 37–47.

    Article  CAS  Google Scholar 

  26. Trafalis DT, Panteli ES, Grivas A, Tsigris C, Karamanakos PN . CYP2E1 and risk of chemically mediated cancers. Expert Opin Drug Metab Toxicol 2010; 6: 307–319.

    Article  CAS  Google Scholar 

  27. Yang T-L, Guo Y, Shen H, Li J, Glessner JT, Qiu C et al. Copy number variation on chromosome 10q26.3 for obesity identified by a genome-wide study. J Clin Endocrinol Metab 2013; 98: E191–E195.

    Article  CAS  Google Scholar 

  28. Webb A, Lind PA, Kalmijn J, Feiler HS, Smith TL, Schuckit MA et al. The investigation into CYP2E1 in relation to the level of response to alcohol through a combination of linkage and association analysis. Alcohol Clin Exp Res 2011; 35: 10–18.

    Article  CAS  Google Scholar 

  29. Schuster-Böckler B, Conrad D, Bateman A . Dosage sensitivity shapes the evolution of copy-number varied regions. PLoS One 2010; 5: e9474.

    Article  Google Scholar 

  30. Woodwark C, Bateman A . The characterisation of three types of genes that overlie copy number variable regions. PLoS One 2011; 6: e14814.

    Article  CAS  Google Scholar 

  31. Zhou J, Lemos B, Dopman EB, Hartl DL . Copy-number variation: the balance between gene dosage and expression in Drosophila melanogaster. Genome Biol Evol 2011; 3: 1014–1024.

    Article  CAS  Google Scholar 

  32. Klein K, Winter S, Turpeinen M, Schwab M, Zanger UM . Pathway-targeted pharmacogenomics of CYP1A2 in human liver. Front Pharmacol 2010; 1: 129.

    Article  CAS  Google Scholar 

  33. Wolbold R, Klein K, Burk O, Nüssler AK, Neuhaus P, Eichelbaum M et al. Sex is a major determinant of CYP3A4 expression in human liver. Hepatology 2003; 38: 978–988.

    Article  CAS  Google Scholar 

  34. Gomes AM, Winter S, Klein K, Turpeinen M, Schaeffeler E, Schwab M et al. Pharmacogenomics of human liver cytochrome P450 oxidoreductase: multifactorial analysis and impact on microsomal drug oxidation. Pharmacogenomics 2009; 10: 579–599.

    Article  CAS  Google Scholar 

  35. Rieger JK, Klein K, Winter S, Zanger UM . Expression variability of absorption, distribution, metabolism, excretion–related microRNAs in human liver: influence of nongenetic factors and association with gene expression. Drug Metab Dispos 2013; 41: 1752–1762.

    Article  CAS  Google Scholar 

  36. Gelboin HV, Goldfarb I, Krausz KW, Grogan J, Korzekwa KR, Gonzalez FJ et al. Inhibitory and noninhibitory monoclonal antibodies to human cytochrome P450 2E1. Chem Res Toxicol 1996; 9: 1023–1030.

    Article  CAS  Google Scholar 

  37. Schröder A, Klein K, Winter S, Schwab M, Bonin M, Zell A et al. Genomics of ADME gene expression: mapping expression quantitative trait loci relevant for absorption, distribution, metabolism and excretion of drugs in human liver. Pharmacogenomics J 2013; 13: 12–20.

    Article  Google Scholar 

  38. Wang K, Li M, Hadley D, Liu R, Glessner J, Grant SFA et al. PennCNV: an integrated hidden Markov model designed for high-resolution copy number variation detection in whole-genome SNP genotyping data. Genome Res 2007; 17: 1665–1674.

    Article  CAS  Google Scholar 

  39. International HapMap Consortium. A haplotype map of the human genome. Nature 2005; 437: 1299–1320.

    Article  Google Scholar 

  40. Conrad DF, Pinto D, Redon R, Feuk L, Gokcumen O, Zhang Y et al. Origins and functional impact of copy number variation in the human genome. Nature 2010; 464: 704–712.

    Article  CAS  Google Scholar 

  41. McCarroll SA, Kuruvilla FG, Korn JM, Cawley S, Nemesh J, Wysoker A et al. Integrated detection and population-genetic analysis of SNPs and copy number variation. Nat Genet 2008; 40: 1166–1174.

    Article  CAS  Google Scholar 

  42. Pinto D, Marshall C, Feuk L, Scherer SW . Copy-number variation in control population cohorts. Hum Mol Genet 2007; 16 (Spec No. 2): R168–R173.

    Article  CAS  Google Scholar 

  43. Redon R, Ishikawa S, Fitch KR, Feuk L, Perry GH, Andrews TD et al. Global variation in copy number in the human genome. Nature 2006; 444: 444–454.

    Article  CAS  Google Scholar 

  44. Stranger BE, Forrest MS, Dunning M, Ingle CE, Beazley C, Thorne N et al. Relative impact of nucleotide and copy number variation on gene expression phenotypes. Science 2007; 315: 848–853.

    Article  CAS  Google Scholar 

  45. R Core Team R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing: Vienna, Austria, 2014.

  46. McCarroll SA, Hadnott TN, Perry GH, Sabeti PC, Zody MC, Barrett JC et al. Common deletion polymorphisms in the human genome. Nat Genet 2006; 38: 86–92.

    Article  CAS  Google Scholar 

  47. Consortium TEP. An integrated encyclopedia of DNA elements in the human genome. Nature 2012; 489: 57–74.

    Article  Google Scholar 

  48. Ward LD, Kellis M . HaploReg: a resource for exploring chromatin states, conservation, and regulatory motif alterations within sets of genetically linked variants. Nucleic Acids Res 2012; 40: D930–D934.

    Article  CAS  Google Scholar 

  49. Kent WJ, Sugnet CW, Furey TS, Roskin KM, Pringle TH, Zahler AM et al. The Human Genome Browser at UCSC. Genome Res 2002; 12: 996–1006.

    Article  CAS  Google Scholar 

  50. McGuire MM, Bowden W, Engel NJ, Ahn HW, Kovanci E, Rajkovic A . Genomic analysis using high-resolution single-nucleotide polymorphism arrays reveals novel microdeletions associated with premature ovarian failure. Fertil Steril 2011; 95: 1595–1600.

    Article  CAS  Google Scholar 

  51. Friedrichsen M, Poulsen P, Wojtaszewski J, Hansen PR, Vaag A, Rasmussen HB . Carboxylesterase 1 gene duplication and mRNA expression in adipose tissue are linked to obesity and metabolic function. PLoS ONE 2013; 8: e56861.

    Article  CAS  Google Scholar 

  52. Fukami T, Nakajima M, Maruichi T, Takahashi S, Takamiya M, Aoki Y et al. Structure and characterization of human carboxylesterase 1A1, 1A2, and 1A3 genes. Pharmacogenet Genomics 2008; 18: 911–920.

    Article  CAS  Google Scholar 

  53. Birchler JA, Riddle NC, Auger DL, Veitia RA . Dosage balance in gene regulation: biological implications. Trends Genet 2005; 21: 219–226.

    Article  CAS  Google Scholar 

  54. Ohtsuki S, Schaefer O, Kawakami H, Inoue T, Liehner S, Saito A et al. Simultaneous absolute protein quantification of transporters, cytochromes P450, and UDP-glucuronosyltransferases as a novel approach for the characterization of individual human liver: comparison with mRNA levels and activities. Drug Metab Dispos 2012; 40: 83–92.

    Article  CAS  Google Scholar 

  55. Oneta CM, Lieber CS, Li J, Rüttimann S, Schmid B, Lattmann J et al. Dynamics of cytochrome P4502E1 activity in man: induction by ethanol and disappearance during withdrawal phase. J Hepatol 2002; 36: 47–52.

    Article  CAS  Google Scholar 

  56. Novak RF, Woodcroft KJ . The alcohol-inducible form of cytochrome P450 (CYP 2E1): role in toxicology and regulation of expression. Arch Pharm Res 2000; 23: 267–282.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

Britta Klumpp and Igor Liebermann are gratefully acknowledged for excellent technical expertise and assistance. We further thank Professor Dr Matthias Schwab for helpful discussions. This work was supported by the Robert Bosch Foundation, Stuttgart, Germany.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to U M Zanger.

Ethics declarations

Competing interests

The authors declare no conflict of interest.

Additional information

Supplementary Information accompanies the paper on the The Pharmacogenomics Journal website

Supplementary information

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Tremmel, R., Klein, K., Winter, S. et al. Gene copy number variation analysis reveals dosage-insensitive expression of CYP2E1. Pharmacogenomics J 16, 551–558 (2016). https://doi.org/10.1038/tpj.2015.69

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/tpj.2015.69

This article is cited by

Search

Quick links