Modeling metabolic variation with single-cell expression data

Cellular metabolism encompasses the biochemical reactions and transportation of various metabolites in cells and their surroundings, which are integrated at all levels of cellular functions. We developed a method to systematically simulate cellular metabolism using single-cell RNA-seq (scRNA-seq) data through constraint-based context specific metabolic modeling. We simulated the NAD+ biosynthesis activity in 7 different mouse tissues, and the simulated NAD+ biosynthesis flux levels showed significant linear correlation with experimental measurements in previous research. We also show that the simulated NAD+ biosynthesis fluxes are reproducible using two additional scRNA-seq datasets.