High-throughput copper speciation with SEC-UV-ICPMS: Insights from Wilson's disease mouse models

Area of Science:

• Biochemistry
• Analytical Chemistry
• Genetics

Background:

• Wilson's disease (WD) is a genetic disorder of copper metabolism due to ATP7B mutations, causing toxic copper accumulation.
• Current ICPMS-based serum copper analyses, including REC and ANCC, show promise but face limitations in live animal studies.
• Challenges include small sample volumes and impractical copper specifications, necessitating alternative analytical methods.

Purpose of the Study:

• To evaluate a size-exclusion chromatography coupled with ultraviolet (SEC-UV)-ICPMS method for precise copper speciation in mouse serum.
• To establish a reliable analytical framework for copper distribution studies in live animal models of Wilson's disease.
• To identify novel biomarkers for diagnosing and monitoring Wilson's disease.

Main Methods:

• A SEC-UV-ICPMS method was developed and optimized for copper speciation in mouse serum, minimizing sample preparation.
• Direct injection-ICPMS was used to determine relative exchangeable copper (REC).
• Strong anion exchange (SAX)-ICPMS was employed for validation and comparison.

Main Results:

• The SEC-UV-ICPMS method effectively separated copper-binding proteins and demonstrated robustness for live mouse studies.
• Distinct copper distribution differences were observed between Wilson's disease mouse models and healthy controls.
• Relative non-ceruloplasmin-bound copper (RNCC) was identified as a potential biomarker with a diagnostic threshold of 52-58%.

Conclusions:

• The SEC-UV-ICPMS platform provides a robust, efficient method for serum copper speciation in live animal studies, overcoming current limitations.
• RNCC is established as a reliable potential biomarker, enhancing precision in copper measurement and supporting therapeutic monitoring.
• This method is crucial for Wilson's disease research, clinical diagnostics, and understanding copper metabolism disorders.