Effects of A Novel Acat Inhibitor, F-1394, on the Progression and Regression of Atherosclerotic Lesions in the Aorta of Cholesterol-Fed Rabbits

Abstract Advanced atherosclerotic lesions are characterized by a progressive increase in the unesterified cholesterol (UC) content and a decrease in its cholesteryl ester (CE) content. In the present study, we examined mechanisms involved in the effect of UC and CE on the expression of paraoxonase 2 (PON2) in macrophages. J774A.1 macrophages were enriched with CE or UC by incubation for 14–48 h with 50 μg acetylated low-density lipoprotein in the absence or presence of the acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor 58035 (50 μg/ml), respectively. Macrophage PON2 mRNA expression, protein abundance and activity were increased only in the UC-enriched cells. In UC-enriched cells, inhibition of phosphatidylinositol 3-kinase (PI3K; using wortmannin or LY294002) attenuated the increase in PON2 mRNA expression by 50%, compared to untreated cells. In addition, we evidenced an increased phosphorylation of Akt in UC-enriched cells. Thus, we conclude from our data that macrophage PON2 expression is upregulated in UC-enriched macrophages through activation of the PI3K signal pathway.

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The ACAT Inhibitor Avasimibe Reduces Macrophages and Matrix Metalloproteinase Expression in Atherosclerotic Lesions of Hypercholesterolemic Rabbits

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/01.atv.20.1.70 ◽

2000 ◽

Vol 20 (1) ◽

pp. 70-79 ◽

Cited By ~ 81

Author(s):

Thomas M. A. Bocan ◽

Brian R. Krause ◽

Wendy S. Rosebury ◽

Sandra Bak Mueller ◽

Xiaokang Lu ◽

...

Keyword(s):

Matrix Metalloproteinase ◽

Atherosclerotic Lesions ◽

Acat Inhibitor

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The Cellular Origin in Atheromatous Lesion

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006800x ◽

1970 ◽

Vol 28 ◽

pp. 202-203

Author(s):

T. M. Murad ◽

H. A. I. Newman ◽

K. F. Kern

Keyword(s):

Smooth Muscle ◽

Smooth Muscle Cells ◽

Rabbit Aorta ◽

Mixed Population ◽

The Other ◽

Cellular Origin ◽

Ultrastructural Studies ◽

Atherosclerotic Lesions ◽

Show Evidence ◽

Early Lesion

The origin of lipid containing cells in atheromatous lesion has been disputed. Geer in his study on atheromatous lesions of rabbit aorta, suggested that the early lesion is composed mainly of lipid-laden macrophages and the later lesion has a mixed population of macrophages and smooth muscle cells. Parker on the other hand, was able to show evidence that the rabbit lesion is primarily composed of lipid-laden cells of smooth muscle origin. The above studies and many others were done on an intact lesion without any attempt of cellular isolation previous to their ultrastructural studies. Cell isolation procedures have been established for atherosclerotic lesions through collagenase and elastase digestion Therefore this procedure can be utilized to identify the cells involved in rabbit atheroma.

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En face dual fluorescence staining of fatty streaks allows observation of initiation and progression of atherosclerotic lesions

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140695 ◽

1995 ◽

Vol 53 ◽

pp. 864-865

Author(s):

Anne M. Klinkner ◽

Crystal R. Waites ◽

Peter J. Bugelski ◽

William D. Kerns

Keyword(s):

Fluorescent Dyes ◽

Nile Red ◽

Dimethyl Formamide ◽

High Cholesterol Diet ◽

Methods Development ◽

Atherosclerotic Lesions ◽

En Face ◽

Biochemical Evaluation ◽

Stock Solutions ◽

Dual Staining

A primary effort in the understanding of the progression of atherosclerotic disease has been methods development for visualization of the atherosclerotic plaque. We introduce a new method for the qualitative analysis of lipids in atherosclerotic fatty streaks which also retains those lipids for biochemical evaluation. An original aspect of the process is the ability to view an entire fatty streak en face, selectively stained for specific lipid classes within the lesion.New Zealand white rabbits were fed a high cholesterol diet(0.15%-0.3% for 14 wks). The aorta was removed and fixed in Carson's phosphate buffered formaldehyde followed by dual staining in the fluorescent dyes Nile red and filipin. Stock solutions of nile red(0.5mg/ml acetone) and filipin(2.5mg/ml dimethyl formamide) were prepared and kept at -20°C; all subsequent steps were at RT. 0.5cm × 1.0cm pieces of aorta were trimmed and adventitia removed. The pieces were then washed 3×15 min in PBS w/o CaMg, soaked in Nile red(NR)/filipin(Fl) stain(100(il NR stock + 200μl Fl stock in 10 ml PBS for 30 min, washed in PBS 3×30 min, rinsed with distilled water, mounted(Crystal Mount, Biomedia) and coverslipped and viewed by fluorescence microscopy.

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