CX₃CR1-deficient atheromas show changes in cellular composition and increased apoptosis. Irradiated apoe^−/− recipients of indicated BM cells were subjected to high-fat diet for 12 weeks, after which their plaque content was analyzed. (A) Histology of atherosclerotic plaque of representative recipient of cx₃cr1^gfp/+, cx₃cr1^gfp/gfp, and cx₃cr1^gfp/gfp;hMRP8bcl2 (cx₃cr1^gfp/gfp;hBcl2) BM cells. CX₃CR1/GFP expression is shown in green; DAPI stain in blue. (B) Immunohistochemistry of atherosclerotic plaque of representative recipient of cx₃cr1^gfp/+ BM cells. CX₃CR1/GFP expression is shown in green, anti–MOMA-2 staining in red, and DAPI in blue. Brightfield shows orange oil (Oil Red O) deposit. Arrows indicate large CX₃CR1/GFP⁺ cells also positive for MOMA-2 expression and orange oil deposit. (C) Histology-based quantification of CX₃CR1/GFP⁺ cells per total plaque areas. Bar diagram shows recipients of cx₃cr1^gfp/+ () and cx₃cr1^gfp/gfp (■), both on either wt (non-tg) or hMRP8bcl2-transgenic background (hBcl2 tg); n = 12. (D) Immunohistochemistry-based quantification of MOMA-2 positive area out of total plaque area. Bar diagram shows recipient of wt (□) and cx₃cr1^gfp/gfp (■), both either on wt (non tg) or hMRP8bcl2 (hBcl2 tg)–transgenic background; n = 12. (E) Immunohistochemistry-based quantification of TUNEL⁺ cells out of total plaque cells (identified by DAPI staining). Bar diagram shows recipient of wt (□) and cx₃cr1^gfp/gfp (■), both on either wt (non-tg) or hMRP8bcl2-transgenic background (hBcl2 tg); n = 12. (F) Immunohistochemistry of atherosclerotic plaque of cx₃cr1^gfp/gfp BM cell recipient. CX₃CR1/GFP expression is shown in green, TUNEL staining is shown in red. Right panel shows higher magnification of area marked by white rectangular. Arrows indicate cells double positive for CX₃CR1/GFP and TUNEL. (G) Immunohistochemistry of atherosclerotic plaque of wt (non-tg) or hMRP8bcl2-transgenic (hBcl2 tg) BM were stained with an antibody specific for human Bcl2 (red). DAPI is shown in blue. Arrow indicates human Bcl2-positive cells. (H) Histology-based quantification of acellular plaque area. Bar diagram shows recipient of wt (□) and cx₃cr1^gfp/gfp (■), both on either wt (non-tg) or hMRP8bcl2-transgenic background (hBcl2 tg); n = 12. *P < .05, **P < .01, ***P < .005 (Student t test).