A targeted proteomics approach for profiling murine cytochrome P450 expression.

Area of Science:

• Pharmacology and Toxicology
• Proteomics
• Biochemistry

Background:

• Cytochrome P450 (P450) enzymes are critical for drug metabolism.
• Mice are vital preclinical models, but comprehensive P450 protein expression data is lacking.
• Understanding P450 expression is key to interpreting mouse drug metabolism studies.

Purpose of the Study:

• To comprehensively define the protein-level expression of P450 enzymes in various mouse tissues.
• To develop and apply a targeted mass spectrometry assay for quantifying P450 enzymes.
• To investigate P450 expression patterns across different ages, sexes, and physiological states (e.g., pregnancy).

Main Methods:

• Global mass spectrometry-based proteomics identified 27 detectable P450 proteins in Balb/c mouse tissues.
• A targeted mass spectrometry assay was developed for sensitive quantification of P450 enzymes.
• The assay was applied to liver microsomes and tissue lysates from mice across developmental stages, ages, sexes, and pregnancy.

Main Results:

• CYP1A2 showed higher abundance in male versus female mouse liver microsomes.
• Hepatic CYP2B9 expression peaked in young mice (3-4 weeks) and was elevated in pregnant mice.
• Sexually dimorphic expression of CYP2B9, 2D26, 2E1, and 4B1 was observed specifically in kidney tissue.

Conclusions:

• A robust targeted proteomics assay for mouse P450 enzymes was established.
• Significant age, sex, and tissue-specific variations in P450 expression were identified.
• These findings provide essential data for improving the translational relevance of mouse models in drug metabolism research.