Mass Spectrometry Probe Combined with Machine Learning to Capture the Relationship between Metabolites and...

Area of Science:

• Biochemistry
• Cellular Metabolism
• Systems Biology

Background:

• Mitochondrial complex activity is crucial for cellular metabolism and physiological processes.
• Existing methods for assessing mitochondrial function often require large sample quantities and fresh tissues, limiting their application.
• Current techniques typically focus on isolated mitochondrial reactions, neglecting the broader metabolic network.

Purpose of the Study:

• To develop a novel, whole-cell level analytical paradigm for evaluating mitochondrial complex activity.
• To establish a method that overcomes the limitations of traditional techniques regarding sample requirements and real-time monitoring.
• To explore the relationship between specific metabolites and mitochondrial complex function.

Main Methods:

• Compilation of a panel of mitochondrial respiratory chain-mapped metabolites (MRCMs).
• Development of a sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method using novel mass spectrometry probes.
• Application of machine learning algorithms to correlate MRCMs with mitochondrial complex activity.

Main Results:

• A highly sensitive UPLC-MS/MS method was established for accurate quantification of MRCMs.
• Machine learning successfully identified key metabolites (NADH, alanine, phosphoenolpyruvate) reflecting Complex I activity at the whole-cell level.
• The identified metabolites' concentrations effectively validated Complex I activity in external datasets.

Conclusions:

• This study presents a novel analytical paradigm for interrogating mitochondrial complex activity by focusing on whole-cell metabolic networks.
• The developed method offers a valuable alternative to existing techniques, especially when sample quantity, type, or timeliness are constraints.
• Shifting focus to interactive metabolic networks provides a more comprehensive understanding of mitochondrial function and its interplay with cellular metabolites.