Figure EV2. TGFβ promotes serine and glycine biosynthesis and glucose oxidation.

• A
  Schematic of stable isotope tracing using d‐glucose labeled with [¹³C] at all six carbons ([U‐¹³C] glucose, shown in red).
• B–G
  Tracing of [U‐¹³C] glucose ([U‐¹³C] Glc) into indicated metabolites. NIH‐3T3 cells were treated with TGFβ or mock for 48 h in DMEM lacking l‐serine and glycine in the presence of 0.5% dialyzed FBS, and the medium was replaced (including all treatments) with DMEM lacking d‐glucose, l‐serine, and glycine and supplemented with [U‐¹³C] Glc for the last 24 or 8 h in the presence of 0.5% dialyzed FBS. Metabolites were measured by LC‐MS.
• H, I
  Tracing of (H) [U‐¹³C] l‐glutamine ([U‐¹³C] Gln) or (I) [α‐¹⁵N] l‐glutamine ([α‐¹⁵N] Gln) into serine and glycine. NIH‐3T3 cells were treated with TGFβ or mock for 48 h in DMEM lacking l‐serine and glycine in the presence of 0.5% dialyzed FBS, and the medium was replaced (including all treatments) with DMEM lacking l‐glutamine, l‐serine, and glycine and supplemented with [U‐¹³C] Gln (H) or [α‐¹⁵N] Gln (I) for the last 8 h in the presence of 0.5% dialyzed FBS. Metabolites were measured by GC‐MS.

Data information: Bars represent the mean + SD. n = 3.