Figure 5.

Tryptophan metabolism in M1-Mɸ versus M2-Mɸs.A, concentrations of tryptophan pathway metabolites in M0-, M1-, and M2-MФs measured by LC-MS. Concentrations were calculated by normalizing the signals of targeting compounds against the signal of 10 μl of 0.1 mM ¹³C₂, 2,2-²H₂, ¹⁵N-Glycine spiked in 200 μl of acetone extracts. B, tryptophan pathway showing metabolites framed in red or green colors indicating an increase in either M1-MФs or M2. IDO: indoleamine 2,3-dioxygenase, TPH: tryptophan hydroxylase, KMO, kynurenine 3-monooxygenase; KYNU, kynureninase; QPRT, quinolinate phosphoribosyltransferase. C, heat map of the expressions of proteins identified in the tryptophan pathway.