High-Density Lipoprotein Function
Recent Advances
Benjamin J. Ansell, MD, FACC,
Karol E. Watson, MD, PhD,
Alan M. Fogelman, MD, FACC,
Mohamad Navab, PhD and
Gregg C. Fonarow, MD, FACC*
Atherosclerosis Research Unit, Division of Cardiology, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California
View larger version (70K):
[in a new window]
|
Figure 1 Model of bidirectional conversion of high-density lipoprotein (HDL) from anti-inflammatory (a) to proinflammatory (b), and the role of myeloperoxidase in catalyzing oxidative modification of HDL, rendering it unable to effect adenosine triphosphate-binding cassette transporter A1-mediated cholesterol transport, modified from Fogelman et al. (2). In association with these changes, apolipoprotein A-1 (apoA-1) and paraoxonase levels decrease, while proinflammatory factors such as lipid oxidation products increase.
|
|
View larger version (26K):
[in a new window]
|
Figure 2 Enzymatic and protein changes within high-density lipoprotein (HDL) during an acute phase reaction. Serum amyloid A (SAA), apolipoprotein J (J), and secretory nonpancreatic phospholipase A2 (sPLA2) are present at higher serum concentrations and incorporate into HDL, while the HDL components apolipoprotein A-I (A-I), paraoxonase 1 (PON1), platelet activating factor acyl hydrolase (PAF-AH), cholesteryl ester transfer protein (CETP), lecithin:cholesterol acyltransferase (LCAT), and phospholipid transfer protein (PLTP) all decrease in concentration within HDL. High-density lipoprotein phospholipid content also falls, along with a reduction in cholesterol esters and an increase in triglycerides, free fatty acids, and free cholesterol. A-II = apolipoprotein A-II. From Rohrer et al. (31).
|
|
View larger version (19K):
[in a new window]
|
Figure 3 (A) High-density lipoprotein (HDL) inflammatory index (mean ± SD), as determined by comparing low-density-lipoprotein-induced monocyte migration in an artery wall cell co-culture assay with HDL from healthy controls, HDL from patients with coronary heart disease/risk equivalents before/after simvastatin 40 mg/day for six weeks, and no HDL (defined as an inflammatory index of 1.0). From Navab et al. (4). (B) High-density lipoprotein inflammatory index from the same subjects, using a cell-free assay.
|
|
|
