NMR Metabolomic Analysis of Caco-2 Cell Differentiation

The high-resolution H-1 NMR spectra as applied to Caco-2 cells during their differentiation into enterocyte like cells are presented. The data clearly reveal differences in the metabolic profiles over time as the Caco-2 cells differentiate. In the H-1 NMR spectra, the aliphatic regions from 4.5 to 1.0 ppm are dominated by peaks from myo-inositol, creatine, taurine, glutamine, glutamate, phosphatidylcholine, choline, alanine and lactate. While a majority of metabolites are present at both the early undifferentiated state and the late differentiated states, the levels of certain metabolites are seen to change dramatically, and in particular, the ratio of myo-inositol and taurine. The NMR spectrum from 10 to 5 ppm shows the aromatic amino acids (Phe, Tyr), NAD, ATP and ribose signals. The appearance of glucose resonances in the differentiated cells (30 days old) spectra suggests that these cells become gluconeogenic. Our study represents a novel method to analyze the differentiation of Caco-2 cells using a metabolomic approach. The results indicate, for the first time, that taurine and glucose biosynthesis occurs in these cells and thus by extension may occur in the intestine. This metabolomic approach can therefore be used to detect novel biological pathways as well as yield useful markers for differentiation.