Abstract
The effects of LDL and Ac-LDL on the growth properties, morphology, and cholesteryl ester (CE) metabolism of the RAW264 macrophage cell line have been characterized. Cells were grown in media supplemented by a defined media (DM) mixture or fetal bovine serum (FBS). The addition of LDL or Ac-LDL to the culture media did not significantly alter cell growth properties. Cytoplasmic deposition of CE was observed by fluorescence microscopy in macrophages treated with LDL or Ac-LDL but not in untreated controls. Dose-response studies have shown that cholesteryl ester (CE) can accumulate in RAW264 treated with LDL. Cellular cholesterol content saturated at 4 hours with 50 μg/ml LDL; this effect may be associated with receptor saturation. Dose-response studies conducted with Ac-LDL in DM have shown dramatic increases in total cell cholesterol content. However, deposition of CE was not observed below Ac-LDL concentrations of 100 μg/ml. This indicates that a critical concentration of Ac-LDL must be reached to trigger deposition in DM. In contrast, no critical concentration of Ac-LDL was observed in macrophages grown in medium supplemented with 10% FBS. Cholesterol esterification in response to LDL and Ac-LDL was examined by 14C-oleic acid incorporation into CE. These results confirmed the mass cellular cholesterol and CE measurements. Kinetic studies conducted with RAW264 cells treated with 50 or 100 μg/ml Ac-LDL resulted in a cholesterol efflux from the cells at 6-12 hours of incubation. Therefore, these studies show that (1) the nature of CE deposition is highly dependent upon the incubation media and (2) CE deposition is very sensitive to Ac-LDL concentration under certain conditions.
Original language | English (US) |
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Pages (from-to) | 29-40 |
Number of pages | 12 |
Journal | Molecular and Cellular Biochemistry |
Volume | 84 |
Issue number | 1 |
DOIs | |
State | Published - Nov 1 1988 |
Externally published | Yes |
Keywords
- LDL
- acetyl-LDL
- cholesteryl ester depostion
- macrophage
ASJC Scopus subject areas
- Molecular Biology
- Clinical Biochemistry
- Cell Biology