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In Vivo Demonstration of Enhanced Oxidized Low Density Lipoprotein Uptake and Cholesterol Esterification by C‐Reactive Protein
Author(s) -
Mohan Dasu Ravi,
Devaraj Sridevi,
Singh Uma,
Yancey Patricia,
Jialal Ishwarlal
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.466.8
Subject(s) - cd36 , chemistry , in vivo , oil red o , lipoprotein , cholesterol , low density lipoprotein , foam cell , albumin , medicine , in vitro , scavenger receptor , endocrinology , biochemistry , receptor , biology , adipogenesis , microbiology and biotechnology
CRP promotes oxidized low density lipoprotein (ox‐LDL) uptake in vitro. However, this effect has not been demonstrated in vivo. In this study, we investigated the effects of CRP on ox‐LDL uptake using the rat sterile air pouch model. Air pouches were made by injecting clean and sterile air into Wistar rats (n=5/group).Group 1 received purified CRP (25 μg/ml)/DiI‐ox‐LDL (50 μg/ml), Group 2 received DiI‐ox‐LDL/albumin (HuSA), and group 3 received 25 μg/ml HuSA. A second set of rats were pretreated with CD32, CD36, CD64 blocking antibodies, or Fucoidin, followed by ox‐LDL/CRP. Pouch macrophages were collected, and used for measuring ox‐LDL uptake by flow cytometry, stained with Oil‐Red O, and intracellular cholesterol accumulation by gas chromatography. CRP significantly increased ox‐LDL uptake in macrophages (9.5±0.8 to 25.7±2.2 MFI; P<0.05) and showed intense Oil‐Red O staining compared to group 2. CRP increased the cholesterol ester accumulation in group 1 rats compared to group 2 (2.8±0.5 to 1.3±0.4; P<0.05). The increased uptake of ox‐LDL by CRP was inhibited by CD32 (66%), CD64 (46%), CD36 (55%), Fucoidin (61%), CD32/CD36 (75%) compared to CRP/ox‐LDL (P<0.05). Our data provides convincing evidence that CRP significantly increases ox‐LDL uptake in rats, and this leads to accumulation of cholesterol esters, the hallmark of atherosclerosis.