Exposure to benzo[a]pyrene of hepatic cytochrome P450 reductase null (HRN) and P450 reductase conditional null (RCN) mice: detection of benzo[a]pyrene diol epoxide-DNA adducts by immunohistochemistry and P-postlabelling

Volker M. Arlt, Miriam C. Poirier, Sarah E. Sykes, Kaarthik John, Michaela Moserova, Marie Stiborova, C. Roland Wolf, Colin J. Henderson, David H. Phillips

    Research output: Contribution to journalArticle

    29 Citations (Scopus)

    Abstract

    Benzo[a]pyrene (BaP) is a widespread environmental carcinogen activated by cytochrome P450 (P450) enzymes. In Hepatic P450 Reductase Null (HRN) and Reductase Conditional Null (RCN) mice, P450 oxidoreductase (Por) is deleted specifically in hepatocytes, resulting in the loss of essentially all hepatic P450 function. Treatment of HRN mice with a single i.p. or oral dose of BaP (12.5 or 125mg/kgbody weight) resulted in higher DNA adduct levels in liver (up to 10-fold) than in wild-type (WT) mice, indicating that hepatic P450s appear to be more important for BaP detoxification in vivo. Similar results were obtained in RCN mice. We tested whether differences between hepatocytes and non-hepatocytes in P450 activity may underlie the increased liver BaP-DNA binding in HRN mice. Cellular localisation by immunohistochemistry of BaP-DNA adducts showed that HRN mice have ample capacity for formation of BaP-DNA adducts in liver, indicating that the metabolic process does not result in the generation of a reactive species different from that formed in WT mice. However, increased protein expression of cytochrome b in hepatic microsomes of HRN relative to WT mice suggests that cytochrome b may modulate the P450-mediated bioactivation of BaP in HRN mice, partially substituting the function of Por.
    Original languageEnglish
    Pages (from-to)160-166
    Number of pages7
    JournalToxicology Letters
    Volume213
    Issue number2
    DOIs
    Publication statusPublished - 2012

    Fingerprint

    NADPH-Ferrihemoprotein Reductase
    DNA Adducts
    Benzo(a)pyrene
    Epoxy Compounds
    Oxidoreductases
    Immunohistochemistry
    Liver
    Cytochromes b
    Cytochrome P-450 Enzyme System
    Hepatocytes
    Environmental Carcinogens
    Detoxification
    Microsomes

    Keywords

    • Animals
    • Benzo(a)pyrene
    • Cytochrome P-450 CYP1A1
    • Cytochromes b5
    • DNA Adducts
    • DNA Damage
    • Female
    • Hepatocytes
    • Immunohistochemistry
    • Liver
    • Mice
    • Mice, Inbred C57BL
    • Mice, Knockout
    • Microsomes, Liver
    • NADPH-Ferrihemoprotein Reductase

    Cite this

    @article{a051bb07c77744d48270028ab28a03e6,
    title = "Exposure to benzo[a]pyrene of hepatic cytochrome P450 reductase null (HRN) and P450 reductase conditional null (RCN) mice: detection of benzo[a]pyrene diol epoxide-DNA adducts by immunohistochemistry and P-postlabelling",
    abstract = "Benzo[a]pyrene (BaP) is a widespread environmental carcinogen activated by cytochrome P450 (P450) enzymes. In Hepatic P450 Reductase Null (HRN) and Reductase Conditional Null (RCN) mice, P450 oxidoreductase (Por) is deleted specifically in hepatocytes, resulting in the loss of essentially all hepatic P450 function. Treatment of HRN mice with a single i.p. or oral dose of BaP (12.5 or 125mg/kgbody weight) resulted in higher DNA adduct levels in liver (up to 10-fold) than in wild-type (WT) mice, indicating that hepatic P450s appear to be more important for BaP detoxification in vivo. Similar results were obtained in RCN mice. We tested whether differences between hepatocytes and non-hepatocytes in P450 activity may underlie the increased liver BaP-DNA binding in HRN mice. Cellular localisation by immunohistochemistry of BaP-DNA adducts showed that HRN mice have ample capacity for formation of BaP-DNA adducts in liver, indicating that the metabolic process does not result in the generation of a reactive species different from that formed in WT mice. However, increased protein expression of cytochrome b in hepatic microsomes of HRN relative to WT mice suggests that cytochrome b may modulate the P450-mediated bioactivation of BaP in HRN mice, partially substituting the function of Por.",
    keywords = "Animals, Benzo(a)pyrene, Cytochrome P-450 CYP1A1, Cytochromes b5, DNA Adducts, DNA Damage, Female, Hepatocytes, Immunohistochemistry, Liver, Mice, Mice, Inbred C57BL, Mice, Knockout, Microsomes, Liver, NADPH-Ferrihemoprotein Reductase",
    author = "Arlt, {Volker M.} and Poirier, {Miriam C.} and Sykes, {Sarah E.} and Kaarthik John and Michaela Moserova and Marie Stiborova and Wolf, {C. Roland} and Henderson, {Colin J.} and Phillips, {David H.}",
    note = "Copyright {\circledC} 2012 Elsevier Ireland Ltd. All rights reserved.",
    year = "2012",
    doi = "10.1016/j.toxlet.2012.06.016",
    language = "English",
    volume = "213",
    pages = "160--166",
    journal = "Toxicology Letters",
    issn = "0378-4274",
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    }

    Exposure to benzo[a]pyrene of hepatic cytochrome P450 reductase null (HRN) and P450 reductase conditional null (RCN) mice : detection of benzo[a]pyrene diol epoxide-DNA adducts by immunohistochemistry and P-postlabelling. / Arlt, Volker M.; Poirier, Miriam C.; Sykes, Sarah E.; John, Kaarthik; Moserova, Michaela; Stiborova, Marie; Wolf, C. Roland; Henderson, Colin J.; Phillips, David H.

    In: Toxicology Letters, Vol. 213, No. 2, 2012, p. 160-166.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Exposure to benzo[a]pyrene of hepatic cytochrome P450 reductase null (HRN) and P450 reductase conditional null (RCN) mice

    T2 - detection of benzo[a]pyrene diol epoxide-DNA adducts by immunohistochemistry and P-postlabelling

    AU - Arlt, Volker M.

    AU - Poirier, Miriam C.

    AU - Sykes, Sarah E.

    AU - John, Kaarthik

    AU - Moserova, Michaela

    AU - Stiborova, Marie

    AU - Wolf, C. Roland

    AU - Henderson, Colin J.

    AU - Phillips, David H.

    N1 - Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

    PY - 2012

    Y1 - 2012

    N2 - Benzo[a]pyrene (BaP) is a widespread environmental carcinogen activated by cytochrome P450 (P450) enzymes. In Hepatic P450 Reductase Null (HRN) and Reductase Conditional Null (RCN) mice, P450 oxidoreductase (Por) is deleted specifically in hepatocytes, resulting in the loss of essentially all hepatic P450 function. Treatment of HRN mice with a single i.p. or oral dose of BaP (12.5 or 125mg/kgbody weight) resulted in higher DNA adduct levels in liver (up to 10-fold) than in wild-type (WT) mice, indicating that hepatic P450s appear to be more important for BaP detoxification in vivo. Similar results were obtained in RCN mice. We tested whether differences between hepatocytes and non-hepatocytes in P450 activity may underlie the increased liver BaP-DNA binding in HRN mice. Cellular localisation by immunohistochemistry of BaP-DNA adducts showed that HRN mice have ample capacity for formation of BaP-DNA adducts in liver, indicating that the metabolic process does not result in the generation of a reactive species different from that formed in WT mice. However, increased protein expression of cytochrome b in hepatic microsomes of HRN relative to WT mice suggests that cytochrome b may modulate the P450-mediated bioactivation of BaP in HRN mice, partially substituting the function of Por.

    AB - Benzo[a]pyrene (BaP) is a widespread environmental carcinogen activated by cytochrome P450 (P450) enzymes. In Hepatic P450 Reductase Null (HRN) and Reductase Conditional Null (RCN) mice, P450 oxidoreductase (Por) is deleted specifically in hepatocytes, resulting in the loss of essentially all hepatic P450 function. Treatment of HRN mice with a single i.p. or oral dose of BaP (12.5 or 125mg/kgbody weight) resulted in higher DNA adduct levels in liver (up to 10-fold) than in wild-type (WT) mice, indicating that hepatic P450s appear to be more important for BaP detoxification in vivo. Similar results were obtained in RCN mice. We tested whether differences between hepatocytes and non-hepatocytes in P450 activity may underlie the increased liver BaP-DNA binding in HRN mice. Cellular localisation by immunohistochemistry of BaP-DNA adducts showed that HRN mice have ample capacity for formation of BaP-DNA adducts in liver, indicating that the metabolic process does not result in the generation of a reactive species different from that formed in WT mice. However, increased protein expression of cytochrome b in hepatic microsomes of HRN relative to WT mice suggests that cytochrome b may modulate the P450-mediated bioactivation of BaP in HRN mice, partially substituting the function of Por.

    KW - Animals

    KW - Benzo(a)pyrene

    KW - Cytochrome P-450 CYP1A1

    KW - Cytochromes b5

    KW - DNA Adducts

    KW - DNA Damage

    KW - Female

    KW - Hepatocytes

    KW - Immunohistochemistry

    KW - Liver

    KW - Mice

    KW - Mice, Inbred C57BL

    KW - Mice, Knockout

    KW - Microsomes, Liver

    KW - NADPH-Ferrihemoprotein Reductase

    UR - http://www.scopus.com/inward/record.url?scp=84864487999&partnerID=8YFLogxK

    U2 - 10.1016/j.toxlet.2012.06.016

    DO - 10.1016/j.toxlet.2012.06.016

    M3 - Article

    C2 - 22759596

    AN - SCOPUS:84864487999

    VL - 213

    SP - 160

    EP - 166

    JO - Toxicology Letters

    JF - Toxicology Letters

    SN - 0378-4274

    IS - 2

    ER -