Optimized high-throughput protocols for comprehensive metabolomic and lipidomic profiling of brain sample

Area of Science:

• Systems Biology
• Metabolomics
• Lipidomics
• Analytical Chemistry

Background:

• Establishing genotype-phenotype links requires analyzing metabolites and lipids in biological systems.
• Tissue samples offer localized, direct information crucial for disease classification and personalized medicine.
• Comprehensive metabolomic and lipidomic analyses demand efficient sample preparation and optimized analytical conditions.

Purpose of the Study:

• To propose simple, rapid, and robust high-throughput analytical protocols for comprehensive analysis of heterogeneous brain samples.
• To systematically optimize parameters for integrated gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-qTOF-MS) using design of experiments (DoE).
• To achieve simultaneous extraction and analysis of metabolites and lipids from small brain tissue samples.

Main Methods:

• Application of five different DoE models (D-optimal, full factorial, fractional, Box-Behnken) to optimize extraction and instrumental parameters.
• Systematic testing of various parameters including sample preparation, chromatographic conditions, and solvent mixtures.
• Integration of GC-MS and LC-qTOF-MS platforms for comprehensive biomolecular profiling.

Main Results:

• A methanol-water-dichloromethane (2:1:3, v/v/v) mixture demonstrated superior simultaneous extraction of metabolites and lipids.
• Key parameters affecting metabolite coverage were identified for both GC-MS (incubation time, temperature, methoxyamine concentration) and LC-qTOF-MS (extraction solvent, reconstitution solvent, ionic strength, column temperature).
• Optimized DoE-based protocols enabled rapid, high-throughput, simultaneous analysis of metabolites, lipids, and proteins from 10 mg brain samples, identifying 475 lipids and 158 metabolites.

Conclusions:

• DoE-based optimization strategies provide a robust framework for comprehensive metabolomic and lipidomic analysis of brain samples.
• The developed single-step extraction and integrated analytical approach significantly enhances efficiency and throughput.
• These protocols facilitate deeper understanding of genotype-phenotype relationships and support advancements in personalized medicine.