Quantification of folate metabolism using transient metabolic flux analysis.

摘要: Systematic quantitative methodologies are needed to understand the heterogeneity of cell metabolism across types in normal physiology, disease, and treatment. Metabolic flux analysis (MFA) can be used infer steady state fluxes, but it does not apply for transient dynamics. Kinetic profiling (KFP) context dynamics, is current gold standard. However, KFP requires measurements at several time points, limiting its use high-throughput applications. Here we propose MFA (tMFA) as a cost-effective methodology quantify metabolic fluxes using metabolomics isotope tracing. tMFA exploits scale separation between dynamics different metabolites obtain mathematical equations relating metabolite concentrations fractions. We show that fractions serine glycine 8 h after addition tracer, while those purines glutathione following with an approximately constant turnover rate per unit metabolite, supporting application folate metabolism. Using tMFA, investigate response antifolate methotrexate breast cancer cells. Our indicates only inhibits purine synthesis also induces increase AMP/ATP ratio, activation AMP kinase (AMPK), inhibition protein synthesis. find some cells, generation one-carbon units from exceeds biosynthetic demand. This work validates have shown effects treatment extend beyond propagate other pathways central