Alterations in Human Liver Metabolome during Prolonged Cryostorage

Area of Science:

• Metabolomics
• Biobanking
• Biochemistry

Background:

• High-quality tissue samples are essential for accurate metabolomics.
• Biobanking storage protocols critically influence sample integrity.
• Realistic storage conditions must be evaluated to ensure reliable metabolomic data.

Purpose of the Study:

• To systematically analyze the impact of realistic biobanking storage scenarios on the liver metabolome.
• To investigate the effects of different storage temperatures and repeated freeze-thaw cycles on metabolite concentrations.
• To provide recommendations for optimized biobanking protocols in metabolomics.

Main Methods:

• Simulated long-term biobanking storage (3 months to 10 years) with repeated temperature cycling between storage (-80 °C, liquid nitrogen, cold nitrogen gas) and retrieval (room temperature, -80 °C).
• Analysis of liver tissue metabolome using liquid chromatography/mass spectrometry (LC/MS).
• Quantification of metabolite concentration changes under various simulated storage conditions.

Main Results:

• Most metabolite concentrations showed less than 5% change during the first simulated year, primarily due to peptide and lipid hydrolysis.
• Storage temperature had a minimal effect on metabolite concentrations, whereas the number of temperature change cycles showed a linear correlation with metabolite alterations.
• Elevated sample temperature during prolonged retrieval periods induced distinct metabolite changes.

Conclusions:

• Repeated temperature fluctuations during biobanking pose a greater risk to liver tissue metabolome integrity than storage temperature alone.
• Optimized biobanking protocols should minimize temperature excursions during sample retrieval and handling.
• Metabolomic signatures of temperature cycling can be used to detect deviations from established storage protocols.