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Expression of human paraoxonase (PON1) during development.
Toby B Cole1, Rachel L Jampsa, Betsy J Walter
1Departments of Environmental Health, University of Washington, Seattle 98195-7720, USA.
Pharmacogenetics
|June 5, 2003
Summary
Paraoxonase (PON1) enzyme levels in newborns are developmentally regulated and reach a plateau between 6 to 15 months. This developmental timing is conserved between mice and humans, impacting organophosphorus compound resistance.
Area of Science:
- Biochemistry
- Genetics
- Developmental Biology
Background:
- Paraoxonase (PON1) is an HDL-associated enzyme crucial for protection against organophosphorus compounds and oxidized lipids.
- Genetic polymorphisms in PON1, including Q192R and -108CT, influence its expression and catalytic activity.
- PON1 levels are subject to developmental regulation, making the timing of its appearance in newborns significant for detoxification capacity.
Purpose of the Study:
- To investigate the developmental trajectory of plasma PON1 levels in humans.
- To compare the developmental regulation of PON1 in humans with that observed in rodent models.
- To assess the role of conserved regulatory elements in PON1's developmental expression.
Main Methods:
- Characterization of PON1 gene polymorphisms and their impact on enzyme activity.
- Longitudinal measurement of plasma PON1 levels in human infants.
- Comparative analysis of PON1 expression in wild-type and PON1-deficient mice and rats with human transgenes.
Main Results:
- Human plasma PON1 levels plateau between 6 to 15 months of age, with significant individual variability.
- In mice and rats, plasma PON1 activity reaches a plateau by 3 weeks of age.
- Human PON1 transgenes in PON1-deficient mice demonstrated a similar developmental expression pattern to wild-type mice, indicating conserved regulatory mechanisms.
Conclusions:
- PON1 expression is developmentally regulated, with a distinct plateau period in early human life.
- The developmental regulation of PON1 appears conserved across species, suggesting conserved genetic control.
- Understanding PON1's developmental timeline is critical for assessing detoxification capabilities and resistance to toxic compounds in infants.