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Title: Hepatic cytochrome P450 activity, abundance, and expression throughout human development

Abstract

Cytochrome P450s are Phase I metabolic enzymes that play critical roles in the biotransformation of endogenous compounds and xenobiotics. The expression and activity of P450 enzymes can vary considerably throughout human development, especially when comparing fetal development to neonates, children, and adults. In an effort to develop a more comprehensive understanding of the ontogeny of P450 expression and activity we employed a multi-omic characterization of P450 transcript expression, protein abundance, and functional activity. To quantify the functional activity of individual P450s we employ activity-based protein profiling, which uses modified mechanism-based inhibitors of P450s as chemical probes, in tandem with proteomic analyses to quantify activity. Our results reveal life-stage-dependent variability in P450 expression, abundance, and activity throughout human development and frequent discordant relationships between expression and activity. The results were used to distribute P450s into three general classes based upon developmental stage of expression and activity. We have significantly expanded the knowledge of P450 ontogeny, particularly at the level of individual P450 activity. We anticipate that our ontogeny results will be useful for enabling predictive therapeutic dosing, and for avoiding potentially adverse and harmful reactions during maturation from both therapeutic drugs and environmental xenobiotics.

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1290393
Report Number(s):
PNNL-SA-112422
Journal ID: ISSN 1521-009X; 453060036
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Drug Metabolism and Disposition, 44(7):984-91; Journal Volume: 44; Journal Issue: 7
Country of Publication:
United States
Language:
English

Citation Formats

Sadler, Natalie C., Nandhikonda, Premchendar, Webb-Robertson, Bobbie-Jo M., Ansong, Charles, Anderson, Lindsey N., Smith, Jordan N., Corley, Richard A., and Wright, Aaron T. Hepatic cytochrome P450 activity, abundance, and expression throughout human development. United States: N. p., 2016. Web. doi:10.1124/dmd.115.068593.
Sadler, Natalie C., Nandhikonda, Premchendar, Webb-Robertson, Bobbie-Jo M., Ansong, Charles, Anderson, Lindsey N., Smith, Jordan N., Corley, Richard A., & Wright, Aaron T. Hepatic cytochrome P450 activity, abundance, and expression throughout human development. United States. doi:10.1124/dmd.115.068593.
Sadler, Natalie C., Nandhikonda, Premchendar, Webb-Robertson, Bobbie-Jo M., Ansong, Charles, Anderson, Lindsey N., Smith, Jordan N., Corley, Richard A., and Wright, Aaron T. 2016. "Hepatic cytochrome P450 activity, abundance, and expression throughout human development". United States. doi:10.1124/dmd.115.068593.
@article{osti_1290393,
title = {Hepatic cytochrome P450 activity, abundance, and expression throughout human development},
author = {Sadler, Natalie C. and Nandhikonda, Premchendar and Webb-Robertson, Bobbie-Jo M. and Ansong, Charles and Anderson, Lindsey N. and Smith, Jordan N. and Corley, Richard A. and Wright, Aaron T.},
abstractNote = {Cytochrome P450s are Phase I metabolic enzymes that play critical roles in the biotransformation of endogenous compounds and xenobiotics. The expression and activity of P450 enzymes can vary considerably throughout human development, especially when comparing fetal development to neonates, children, and adults. In an effort to develop a more comprehensive understanding of the ontogeny of P450 expression and activity we employed a multi-omic characterization of P450 transcript expression, protein abundance, and functional activity. To quantify the functional activity of individual P450s we employ activity-based protein profiling, which uses modified mechanism-based inhibitors of P450s as chemical probes, in tandem with proteomic analyses to quantify activity. Our results reveal life-stage-dependent variability in P450 expression, abundance, and activity throughout human development and frequent discordant relationships between expression and activity. The results were used to distribute P450s into three general classes based upon developmental stage of expression and activity. We have significantly expanded the knowledge of P450 ontogeny, particularly at the level of individual P450 activity. We anticipate that our ontogeny results will be useful for enabling predictive therapeutic dosing, and for avoiding potentially adverse and harmful reactions during maturation from both therapeutic drugs and environmental xenobiotics.},
doi = {10.1124/dmd.115.068593},
journal = {Drug Metabolism and Disposition, 44(7):984-91},
number = 7,
volume = 44,
place = {United States},
year = 2016,
month = 7
}
  • Twelve forms of human hepatic cytochrome P450 were expressed in hepatoma cells by means of recombinant vaccinia viruses. The expressed P450s were analyzed for their abilities to activate the potent hepatocarcinogen aflatoxin B{sub 1} to metabolites having mutagenic or DNA-binding properties. Five forms, P450s IA2, IIA3, IIB7, IIIA3, and IIIA4, activated aflatoxin B{sub 1} to mutagenic metabolites as assessed by the production of His revertants of Salmonella typhimurium in the Ames test. The same P450s catalyzed conversion of aflatoxin B{sub 1} to DNA-bound derivatives as judged by an in situ assay in which the radiolabeled carcinogen was incubated with cellsmore » expressing the individual P450 forms. Seven other human P450s, IIC8, IIC9, IID6, IIE1, IIF1, and IIIA5, and IVB1, did not significantly activate aflatoxin B{sub 1} as measured by both the Ames test and the DNA-binding assay. Moreover, polyclonal anti-rat liver P450 antibodies that crossreact with individual human P450s IA2, IIA3, IIIA3, and IIIA4 each inhibited aflatoxin B{sub 1} activation catalyzed by human liver S-9 extracts. Inhibition ranged from as low as 10% with antibody against IIA3 to as high as 65% with antibody against IIIA3 and IIIA4. These results establish that metabolic activation of aflatoxin B{sub 1} in human liver involves the contribution of multiple forms of P450.« less
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