Figure 7.

CD36 mediates the uptake of phenylpyruvate in macrophages

(A) The bubble plot shows the plasma membrane proteins identified in the LiP-SMap assay. The color of the circle indicates the p value.

(B) Immunostaining and statistical analysis showing the uptake of phenylpyruvate in BMDMs with or without knockdown of CD36. The FITC antibody indicated phenylpyruvate, and the lipid raft antibody indicated plasma membrane (n = 3). Scale bar, 50 μm.

(C) RT-qPCR results showing the relative mRNA expression of CD36 and LRP1 in BMDMs treated with increasing phenylpyruvate concentrations (n = 3).

(D) Immunoblot analysis of total CD36 protein expression in BMDMs treated with increasing phenylpyruvate concentrations. The black triangle indicates increasing phenylpyruvate concentrations starting from the left: 200, 400, and 800 μM (n = 3).

(E) Statistical analysis and representative histograms from flow cytometry data showing CD36 protein expression on the surface of BMDMs treated with increasing phenylpyruvate concentrations (n = 3).

(F) Immunoblot analysis of the supernatant and cell extracts in the indicated BMDMs, with or without knockdown of CD36, and then treated with phenylpyruvate for 4 h and LPS for 24 h, followed by stimulation with ATP for 45 min (n = 3).

(G–I) ELISA measuring the levels of the inflammatory factors IL-1β, IL-18, and TNFα in the supernatant of BMDMs, with or without knockdown of CD36, and then treated with phenylpyruvate for 4 h and LPS for 24 h, followed by stimulation with ATP for 45 min (n = 3).

(J) Schematic view of CD36 (full length).

(K) Representative images of autodocking for phenylpyruvate to the extracellular section of CD36 protein. Data are shown as mean ± SD. ∗p < 0.05, ∗∗p < 0.01; n.s., not significant.