Atherosclerosis scavenger receptors role

Y. Yamada, T. Doi, T. Hamakubo and T. Kodama, Scavenger receptor family proteins roles for atherosclerosis, host defense and disorders of the central nervous system, Cell Mol. Life Sci. 54 (1998) 628-640. 

Fuhrman, B., Volkova, N., and Aviram, M., Oxidative stress increases the expression of the CD36 scavenger receptor and the cellular uptake of oxidized low-density lipoprotein in macrophages from atherosclerotic mice Protective role of antioxidants and of paraoxonase, Atherosclerosis, 161, 307, 2002. 

The receptor SR-BI differs In two Important respects from the LDL receptor. First, SR-BI clusters on microvilli and in cell-surface lipid rafts (Chapter 5), not In coated pits as does the LDL receptor. Second, SR-BI mediates the transfer of lipids across the membrane, not endoc3rt osIs of entire LDL particles as mediated by the LDL receptor. A multifunctional receptor, SR-BI can mediate the selective uptake from lipoproteins of diverse lipids (e.g., cholesteryl esters, vitamin E) it also functions in the reverse direction to facilitate the export of unesterified cholesterol from cells to bound lipoproteins. SR-BI has a structure similar to that of the fatty acid transporter CD36, and they both belong to the superfamily of scavenger receptors as discussed later, some of these receptors apparently play a role In the onset of atherosclerosis. 

Although modifications of ion channels could contribute to the late stages of cardiovascular disease, formation of IsoK/LG adducts may also play a role early in atherosclerosis. Atherosclerosis is initiated when macrophages take up oxidized low density lipoprotein (oxLDL) via scavenger receptors such as SR-A and CD36 to form foam cells. In vitro oxidation of LDL results in the formation of IsoK adducts on the particle (Brame et ah, 1999 Salomon et al., 1997a ... 

Fig. 5. Scavenger receptors (SRs). Structural features of scavenger receptors with proposed roles in atherosclerosis. The plasma membrane or the endosomal membrane (for CD68, which is mainly found in the endosomal compartment) is indicated by the vertical line, with the cytoplasmic domains to the left. The individual structural domains are described in the box. SRCL, SR with C-type lectin MARCO, macrophage receptor with collagenous structure SREC, SR expressed by endothelial cells SR-PSOX/CXCL16, membrane-bound chemokine L16 other SRs are described in the text (Section 7). Not drawn to scale.

Nicholson AC, Han J, Febbraio M, Silversterin RL, Hajjar DP. Role of CD36, the macrophage class B scavenger receptor, in atherosclerosis. Ann N Y Acad Sci 2001 947 224-228. 

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