Fig. 1. PSS modulates endothelial metabolome and increases SCD1-catalyzed metabolites.

(A) A custom-built dynamic flow system was used to simulate spatial and temporal variations in shear stress in the arterial system. The machine language (LabVIEW) drives a peristaltic pump to generate pulsatile wave forms. The configuration of the flow channel (contraction and extraction) was designed to provide the well-defined pulsatile flow with the specific slew rates (∂τ/∂t), time-averaged shear stress (τ_ave), frequency [hertz (Hz)], and amplitude to simulate exercise-augmented PSS or OSS. The flow channel was maintained inside the incubator at 37°C with 5% CO₂. The confluent HAEC monolayer was seeded on the glass slides in the flow channel. (B) Metabolite samples were collected from HAEC lysates under the static condition (control or no flow, n = 5), OSS (n = 4), or PSS (n = 4 at 1 Hz for 4 hours) for the untargeted metabolic analysis. PSS or OSS significantly increased the lipid metabolite OA by 2- and 1.3-fold, respectively. (C) Biosynthesis of MUFA depicts that SCD1 catalyzes the rate-limiting step for the conversion of SFA (palmitic and stearic) to MUFA (palmitoleic and oleic). (D) The heatmap reveals an increase in both glycolytic and fatty acid metabolites. The data were analyzed after normalization and scaling using the Pareto method. (E) Score plots by the principal component analysis (PCA) revealed a separation of the representative endothelial metabolites. Ellipses represent 90% confidence intervals for the PSS, OSS, and static groups, respectively.