These results suggest that the alteration in ox-LDL uptake in macrophages induced by targeting of CD147 is possibly due to regulation of the scavenger receptor CD36. Open in a separate window FIGURE 7 Macrophage-specific deficiency diminishes CD36 expression and may exert other protective effects in atherosclerosis. sets involved in atherosclerosis are illustrated as heatmaps and include LDL clearance, plasma lipoprotein clearance, platelet aggregation, and collagen degradation. Image_1.JPEG (1.3M) GUID:?1BDDC518-6A0F-409D-8FA1-3EBB8375D24E Data Availability StatementOur RNA-seq original sequence data have been LH 846 submitted to the LH 846 database of the NCBI Sequence Read Archive (http://trace.ncbi.nlm.nih.gov/traces/sra) under the accession number: PRJNA665796. Abstract The persistence of macrophage-derived foam cells in the artery wall fuels atherosclerosis development. However, the mechanism of foam cell formation regulation remains elusive. We are committed to determining the role that CD147 might play in macrophage foam cell formation during atherosclerosis. In this study, we found that CD147 expression was primarily increased in mouse and human atherosclerotic lesions that were rich in macrophages and could be upregulated by ox-LDL. High-throughput compound screening indicated that ox-LDL-induced CD147 upregulation in macrophages was achieved through PI3K/Akt/mTOR signaling. Genetic deletion of macrophage protected against foam cell formation by impeding cholesterol uptake, probably through the scavenger receptor CD36. The opposite effect was observed in primary macrophages isolated from macrophage-specific lipogenesis and fatty acid-oxidation. Given its function in inflammation and metabolism, we have been committing to determining the role that CD147 might play in atherosclerosis, LH 846 especially in foam cell formation. In the present study, we found that CD147 expression is specifically increased in LH 846 mouse and human atherosclerotic lesions that are rich in macrophages. We demonstrated that CD147 is upregulated by ox-LDL in macrophages through PI3K/Akt/mTOR signaling. We first found that CD147 plays an important role in foam cell formation. Macrophage-specific knockout inhibits foam cell formation, whereas macrophage-restricted overexpression promotes this process. The underlying mechanism might include altered ox-LDL uptake through regulation of the scavenger receptor CD36. Moreover, our findings indicate that macrophage-specific deficiency may protect against atherosclerosis in versatile aspects. Altogether, CD147 may become a potential target for prevention and treatment of atherosclerosis in the future. Materials and Methods Antibodies and Reagents Anti-human CD147, FITC anti-human CD147 (53027, Thermo Fisher Scientific), and anti-human tubulin antibodies were produced by our lab (Chen, 1992; Cui et al., 2018; Lu et al., 2018; Wang et al., 2020). The other antibodies used in this study were as follows: Rabbit anti-mouse CD147 (ab188190), anti-human CD68 (ab955), anti–SMA (ab7817), anti-ABCG1 (ab52617), and anti-SR-A (ab151707) antibodies were purchased from Abcam (Cambridge, United Kingdom); anti-mouse CD68 (MCA1957) and anti-F4/80 (MCA497) antibodies were purchased from Bio-Rad (California, United States). PE anti-mouse CD147 (562676) antibody was purchased from BD Biosciences (Franklin Lakes, NJ, United States); anti-p-PI3K (4228), anti-PI3K (4292), anti-p-Akt (4058), anti-Akt (9272), anti-p-mTOR (5536), anti-mTOR (2983), and anti-p-p65 (3033) antibodies were purchased from Cell Signaling Technology (MA, United States); PerCP anti-CD11b (101230) and FITC anti-F4/80 (123107) antibodies were purchased from BioLegend (SanDiego, United States); anti-mouse tubulin (EM0103) antibody was purchased from HuaBio (Hangzhou, China); anti-ABCA1 (NB400-105) antibody was purchased from Novus Biologicals (United States); goat anti-mouse CD147 (AF772), anti-CD31 (AF3628), anti-LDLR (AF2255), and anti-CD36 (AF2519) antibodies were purchased from R&D (Abingdon, United Kingdom); anti-IB (10268-1-AP) and anti-p65 (10745-1-AP) antibodies were purchased from Proteintech (IL, United States); isotype-matched control antibody mIgG was purchased from Sigma-Aldrich (Darmstadt, Germany); horseradish peroxidase-conjugated anti-mouse, anti-rabbit, and anti-goat secondary antibodies and fluorescent secondary antibodies were purchased from Invitrogen (Carlsbad, CA, United States). Ox-LDL, LDL, ac-LDL, DiI-ox-LDL, and HDL were obtained from Peking Union-Biology (Beijing, China). The inhibitor library was purchased from Selleck (Houston, Texas, United States). PMA, Oil Red O, and ApoAI were purchased from Sigma-Aldrich. Bodipy 493/503 (D3922) was purchased from Invitrogen (Carlsbad, CA, United States). Mice C57BL/6J mice were obtained from Vitalstar Biotechnology (Beijing, China), ADFP and gene, were constructed in our lab (Yao et al., 2013). To generate macrophage-specific knockout (knockin mice, we first generated mice heterozygous for floxed STOP CD147 (the gene was preceded by a stop codon that was flanked by two Loxp sites) after the promoter (CD147KIf/+) (Cyagen Biosciences, China). To generate macrophage-specific knockin (deletion and overexpression in macrophages were confirmed by western blotting and real-time PCR (RT-PCR). For atherosclerosis model induction, 8 week-old gene expression. Oil Red O Staining Analysis Cells were fixed with 4% paraformaldehyde (PFA) and then washed with PBS. After a rinse with isopropanol, the cells were stained with Oil Red O for 2 min and counterstained with hematoxylin. Cell morphology was observed using a microscope system (Olympus, Tokyo, Japan)..