Foam cell formation from macrophages with subsequent fatty streak formation plays a key role in early atherogenesis. Foam cell formation is thought to be induced by Low Density Lipoproteins (LDL), including oxidized LDL (OxLDL) or minimally modified LDL (mmLDL). Understanding the molecular mechanisms involved in OxLDL- and mmLDL-induced foam cell formation is of fundamental importance for ather...

The hydromethylglutaryl coenzyme A (HMG CoA) reductase inhibitors, “statins,” have been remarkably effective in reducing low-density lipoprotein (LDL) cholesterol concentration, decreasing the incidence of coronary heart disease (CHD) and stroke, and extending survival (1–5). Statins inhibit the synthesis of cholesterol primarily in the liver. The hepatocyte, as its content of cholesterol decre...

The lipid metabolism of photoreceptors depends in part on the retinal pigment epithelium (RPE). One aspect of cholesterol homeostasis in cultured bovine RPE was evaluated by measuring low-density lipoprotein (LDL) and scavenger receptor activity with [125I]-LDL and [125I]Ac-LDL, respectively. Incubation of RPE cells in the presence of increasing concentrations of LDL or Ac-LDL resulted in down-...

Pharmacologic doses of 17a-ethinyl estradiol have been reported to cause a marked lowering of plasma lipoprotein levels in the rat. The drop in plasma low density lipoprotein (LDL) is associated with enhanced uptake of LDL by the liver. In the current studies, we show that membranes prepared from livers of ethinyl estradiol-treated rats exhibit a 3to lo-fold increase in saturable binding sites ...

Scavenger receptors (SRs), which recognize modified low-density lipoprotein (LDL) by oxidation or acetylation, are a group of receptors on plasma membrane of macrophages and other cell types. These receptors by facilitating modified LDL uptake are a primary step in the intracellular accumulation of modified LDL and formation of fatty streak. Non-coding RNAs (ncRNAs) are a group of functional RN...

the non-enzymatic glycation of low density lipoprotein (ldl) is a naturally occurring chemical modification of apolipoprotein b as a result of condensation between lysine residues and glucose. glycated ldl is poorly recognized by ldl receptors and initiates different processes that can be considered proatherogenic. thus, ldl glycation may contribute in the increased atherosclerotic risk of pati...

The atherosclerotic lesion is characterized by the presence of cholesterol-loaded foam cells. Chinese hamster ovary (CHO) cells do not normally store cholesteryl esters because low density lipoprotein (LDL) receptors are suppressed by exposure of these cells to LDL cholesterol. We transfected LDL receptor cDNA linked to the simian virus 40 early promoter into CHO cells (CHO 29) and found that L...

At the present time the most useful technique with which to examine the kinetics of low-density lipoprotein (LDL) cholesterol in vivo is the labeled LDL turnover study. However, a major limitation of this method is that, despite its ability to accurately measure both the plasma LDL concentration and LDL production rate, it cannot directly quantify LDL receptor activity. The present study define...

During atherosclerosis, low-density lipoprotein (LDL)-derived cholesterol accumulates in macrophages to form foam cells. Macrophage uptake of LDL promotes foam cell formation but the mechanism mediating this process is not clear. The present study investigates the mechanism of LDL uptake for macrophage colony-stimulating factor (M-CSF)-differentiated murine bone marrow-derived macrophages. LDL ...

Macrophage scavenger receptors mediate the recognition of a wide range of negatively charged macromolecules including modified low density lipoproteins (LDL). Truncated bovine receptors lacking residues 330-342, which include the conserved lysine cluster of a collagen-like domain, were unable to degrade modified LDL in spite of their expression on the cell surface. Substitution of lysine 337 in...