Uptake of acetylated low density lipoprotein (ac-LDL) by synovial cells.
Acetylated low density lipoprotein (ac-LDL) is known to be incorporated into monocyte/macrophages. We examined the uptake of fluorescence-labeled ac-LDL as well as the surface expression of CD14 using flow cytometry, in order to identify macrophage-like type A synoviocytes in the synovium of patients with rheumatoid arthritis (RA) (n = 15) and osteoarthritis (OA) (n = 5). The mean (+/- SD) percentage of ac-LDL uptake cells in RA synoviocytes (38.3 +/- 19.9%) was relatively higher than that in OA synoviocytes (16.6 +/- 8.7%) (p < 0.05). Also the proportion of ac-LDL incorporating cells paralleled, but was higher than, that of CD14 positive cells (r = 0.91, p < 0.001). This method is helpful in determining macrophage-like type A synoviocytes, and the presence of CD14-negative macrophage-like synoviocytes has been revealed.
Higaki
M
M
Department of Immunological Diseases, Tokyo Medical and Dental University, Japan.
Sato
K
K
Miyasaka
N
N
Nishioka
K
K
D000368:Aged; D001172:Arthritis, Rheumatoid / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008077:Lipoproteins, LDL / Q000493:pharmacokinetics*; D008264:Macrophages / Q000166:cytology; D008297:Male; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology; D010003:Osteoarthritis / Q000378:metabolism; D013583:Synovial Membrane / Q000166:cytology* / Q000378:metabolism*
D008077:Lipoproteins, LDL; C032629:acetyl-LDL