Figure 2.
TGs Promote Cell Viability in Low O2 and Serum by Absorbing FA Saturation
(A) Viability of A498 cells expressing inducible shRNA against DGAT1 and DGAT2 mRNAs (DGAT shRNA), assessed after 72 hr under the indicated conditions (hypoxia = 0.5% O2; serum deprivation = low serum, 0.5% fetal bovine serum [FBS]) by Annexin-propidium iodide (PI) flow cytometry assay.
(B) Viability of cells expressing inducible DGAT shRNAs after 72 hr under the indicated conditions (SCDi, 1 μM CAY10566) by Annexin-PI assay using flow cytometry.
(C) Volcano plot showing fold change and significance of alterations in the lipidome of A498 cells cultured in low (0.5%) versus high (5%) serum. Lipids with ≥ 1.5 fold change and p ≤ 0.05 are displayed in color to denote lipid class.
(D) Changes in FA composition or saturation of TGs, calculated by aggregating TG abundances for species containing 0, 1, or 2+ SFA chains separately. Values are normalized to control conditions (5% serum).
(E) Lipid class-specific saturation indices (defined by (palmitate + stearate) / oleate) for A498 cells cultured under hypoxic (0.5% O2) versus normoxic conditions (both in low serum).
(F) As (E) but with pharmacological SCD inhibition (1 μM CAY10566) instead of hypoxia.
(G) Effect of serum deprivation and DGAT shRNA on total TG abundances.
(H) Changes in FA makeup of TGs following DGAT knockdown; values were calculated by aggregating TG abundances for species containing 0, 1, or 2+ SFA chains separately. Values were normalized to the control condition (vehicle [Veh] treatment).
(I) TG saturation indices for the indicated conditions. Values are relative to normoxic untreated cells.
(J) As (G) but with pharmacological SCD inhibition (1 μM CAY10566). Values are relative to the untreated vehicle control.
Data are means of 3 (A, B, and D–J) or 5 (C) replicate wells and were confirmed in independent experiments; error bars represent SD. Statistical significance by t test or ANOVA, as appropriate. ∗∗p < 0.05, and ∗∗∗p < 0.005. See also Figure S2.