Expression of the novel scavenger receptor SR-PSOX in cultured aortic smooth muscle cells and umbilical endothelial cells.

Abstract

To the Editor: In the November issue of Arteriosclerosis, Thrombosis, and Vascular Biology , Minami et al1 demonstrated expression of the novel scavenger receptor for phosphatidylserine and oxidized lipoprotein (SR-PSOX) in lipid-laden macrophages accumulated in the intima of human atherosclerotic lesions. Because SR-PSOX seems to be identical to the membrane-anchored chemokine CXCL16,2,3⇓ which may play a dual role in inflammation and homeostasis, Minami et al1 discussed the potential regulation of SR-PSOX by pro-inflammatory cytokines. Although the authors did not detect SR-PSOX in smooth muscle cells (SMCs) and endothelial cells (ECs), they did discuss the possible expression of SR-PSOX in these cell types. Until now, only the expression of the scavenger receptors SR-AI/II,4 CD36,5 and LOX-16 in SMCs has been described. In our studies on the formation of SMC-derived foam cells during atherogenesis, we have focused on the expression of scavenger receptors,7 including SR-PSOX, in SMCs and ECs. We have also investigated the influence of cytokines on the expression of SR-PSOX in SMCs. Reverse transcriptase–polymerase chain reaction (PCR; primers for human SR-PSOX: 5′-TACACGAGGTTCCAGCTCCT-3′ and 5′-GGGGGCTGGT- AGGAAGTAAA-3′, porcine SR-PSOX: 5′-TATGTGGAGGCAGCAG- TGAC-3′ and …