Development of a Real-Time Monitoring System for the Adherent Human Keratinocyte Metabolism by Live-Cell Metabolic NMR with Illumination.

Our skin is constantly exposed to the external environment, and the epidermis, in particular, responds to various external stimuli by producing biomolecules, including proteins, lipids, and metabolites. Therefore, a real-time metabolic monitoring system for living keratinocytes is essential. Metabolomics, one of the key fields in omics research, has emerged as a powerful tool for the comprehensive characterization and quantification of biological molecule pools. However, most conventional metabolomics studies rely on cell quenching or lysis methods, which may introduce artifactual stimuli and potentially alter the metabolite profiles of living cells, as fast signaling events such as phosphorylation can occur within milliseconds to seconds. Consequently, conducting omics research on living organisms in real time is of great value, as it can provide unique insights that are not achievable through conventional methods. In this study, we established a novel, noninvasive, real-time metabolic monitoring system termed "live-cell metabolic NMR with illumination". This innovative technique enables the evaluation of the metabolic responses of living human keratinocytes to various external stimuli, allowing for the investigation of real-time metabolic dynamics in a physiologically relevant environment.