Fig. 4. Myeloid TRIB1 induces reciprocal changes in oxLDL and HDL receptor expression in human and mouse macrophages.

(A) TRIB1 RNA levels in monocytes and MDMs of CTS participants (24). Correlation (R² < 0.001, P = 0.47) was performed on 596 paired monocyte and MDM samples. (B) MDM (n = 596) and monocytes (n = 758) were ranked according to TRIB1 RNA contents and gene expression values in the top and bottom quartiles compared. Log₂ fold changes (FC) of specified RNAs in TRIB1^High (n = 149) versus TRIB1^Low (n = 149) MDM, with associated P values. (C) FC and P values for differential expression of RNAs encoding representative scavenger receptors, including CD36, which mediates (ox)-phospholipid and long-chain fatty acid uptake (39), the acetylated-LDL scavenging receptor (40), and macrophage scavenger receptor (40). Comparisons are between TRIB1^High versus TRIB1^Low MDMs and between TRIB1^High (n = 191) versus TRIB1^Low (n = 191) monocytes. (D) RT-qPCR quantification of RNA (mean ± SEM) in BMDM prepared from specified mice (n = 5 to 9 per group). (E) Immunocytochemistry of nonpolarized Trib1^mWT and Trib1^mTg BMDMs. OLR1 (red), nuclei counterstained with 4′,6-diamidino-2-phenylindole (DAPI) (blue). Scale bar, 50 μm. Quantifications performed on BMDMs prepared from four to five mice per group. (F) Western blot analysis of OLR1 in Trib1^mWT and Trib1^mTg BMDMs (n = 3 to 5 per group). In (D) to (F), significance was determined by Student’s t test; *P < 0.05, and **P < 0.01.