Inhibitory effects of rosa roxburghii tratt juice on in vitro oxidative modification of low density lipoprotein and on the macrophage growth and cellular cholesteryl ester accumulation induced by oxidized low density lipoprotein

2001 ◽  
Vol 313 (1-2) ◽  
pp. 37-43 ◽  
Author(s):  
Chunni Zhang ◽  
Xiaozhuan Liu ◽  
Hongjuan Qiang ◽  
Ke Li ◽  
Junjun Wang ◽  
...  
1991 ◽  
Vol 278 (2) ◽  
pp. 429-434 ◽  
Author(s):  
V M Darley-Usmar ◽  
A Severn ◽  
V J O'Leary ◽  
M Rogers

Macrophages derived from the human monocyte cell line THP-1 or isolated from the peritoneum of C3H/HEJ mice were incubated with oxidized low-density lipoprotein (LDL) and the total glutathione content (oxidized plus reduced) was measured. An initial depletion of glutathione was followed by an increase, such that after a period of 24 h the glutathione content has approximately doubled. This response required the oxidation of the lipid phase of the LDL molecule, since both native LDL and acetylated LDL had little effect on glutathione levels. The response of the cells to oxidized LDL was dependent on the extent of oxidative modification of the protein. It was also found that 4-hydroxynonenal had a similar effect on THP-1 cells, and we suggest that this or other aldehydes present in oxidized LDL causes the induction of glutathione synthesis in response to an initial oxidative stress and consequent glutathione depletion. In addition, we found that both cell types possess transferases and peroxidases capable of detoxifying aldehydes and peroxides. However, treatment of cells with oxidized LDL or 4-hydroxynonenal for a period of 24 h had no effect on the activities of these enzymes.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5120
Author(s):  
Mamiko Yamashita ◽  
Yoshiaki Nomura ◽  
Misao Ishikawa ◽  
Shinji Shimoda ◽  
Nobuhiro Hanada

Calcification plays an important role in the human body in maintaining homeostasis. In the human body, the presence of a high amount of oxidized low-density lipoprotein (ox-LDL) is a consistent feature of the local areas that are common sites of ectopic calcification, namely dental calculus, renal calculus, and the areas affected by arteriosclerosis. Hence, ox-LDL may have some effect on calcification. Scanning electron microscopy (SEM) observation revealed a high amount of amorphous calcium phosphate (ACP) when ox-LDL was included in the solution. In the in vitro experiment, the highest amount of precipitation of calcium phosphate was observed in the solution containing ox-LDL compared to the inclusion of other biomaterials and was 4.2 times higher than that of deionized water for 4.86 mM calcium and 2.71 mM phosphate. The morphology of calcium phosphate precipitates in the solution containing ox-LDL differed from that of the precipitates in solutions containing other biomaterials, as determined by transmission electron microscopy (TEM). Through the time course observation of the sediments using TEM, it was observed that the sediments changed from spherical or oval shape to a thin film shape. These results indicate that sediments acquired a long-range order array, and the phase transitioned from non-crystalline to crystalline with an increased time and density of ACP. Thus, it is concluded that ox-LDL promoted ACP precipitation and it plays an important role in ectopic calcification.


2005 ◽  
Vol 393 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Jane E. Murphy ◽  
Daryl Tacon ◽  
Philip R. Tedbury ◽  
Jonathan M. Hadden ◽  
Stuart Knowling ◽  
...  

The LOX-1 (lectin-like oxidized low-density lipoprotein receptor-1) scavenger receptor regulates vascular responses to oxidized-low-density-lipoprotein particles implicated in atherosclerotic plaque formation. LOX-1 is closely related to C-type lectins, but the mechanism of ligand recognition is not known. Here we show that human LOX-1 recognizes a key cellular phospholipid, PS (phosphatidylserine), in a Ca2+-dependent manner, both in vitro and in cultured cells. A recombinant, folded and glycosylated LOX-1 molecule binds PS, but not other phospholipids. LOX-1 recognition of PS was maximal in the presence of millimolar Ca2+ levels. Mg2+ was unable to substitute for Ca2+ in LOX-1 binding to PS, indicating a Ca2+-specific requirement for bivalent cations. LOX-1-mediated recognition of PS-containing apoptotic bodies was dependent on Ca2+ and was decreased to background levels by bivalent-cation chelation, LOX-1-blocking antibodies or PS-containing liposomes. The LOX-1 membrane protein is thus a Ca2+-dependent phospholipid receptor, revealing novel recognition of phospholipids by mammalian lectins.


2000 ◽  
Vol 11 (10) ◽  
pp. 1826-1836
Author(s):  
MIKI NAGASE ◽  
SHINYA KANAME ◽  
TAKASHI NAGASE ◽  
GANG WANG ◽  
KATSUYUKI ANDO ◽  
...  

Abstract. Oxidized low-density lipoprotein (OxLDL) has been implicated in atherosclerosis and glomerulosclerosis. LOX-1 is a recently identified OxLDL receptor that is abundantly expressed in vascular endothelial cells. The aim of the present study was to investigate LOX-1 expression in the kidneys of hypertensive rats. Dahl salt-sensitive (DS) and salt-resistant (DR) rats were fed a 0.3% or 8% NaCl diet. Some DS 8% rats were treated with manidipine or hydralazine. LOX-1 gene expression was markedly elevated in the kidneys and glomeruli of hypertensive DS 8% rats compared with those of normotensive DR and DS 0.3% rats. Prolonged salt loading further increased the renal LOX-1 expression in DS rats. The LOX-1 upregulation in DS 8% rats was accompanied by renal overexpression of transforming growth factor-β1 and type I collagen, impaired renal function, and histologic glomerulosclerotic changes, all of which were ameliorated by antihypertensive treatment. LOX-1 was indeed expressed in the glomeruli in vivo and in cultured glomerular cells in vitro. However, LOX-1 expression was elevated in the aorta but not the kidneys of spontaneously hypertensive rats, which exhibited hypertension but minor glomerulosclerotic changes. In conclusion, the LOX-1 upregulation in the kidney of DS 8% rats was parallel to glomerulosclerotic changes and renal dysfunction, suggesting a possible pathogenetic role for renal LOX-1 in the progression to hypertensive glomerulosclerosis.


1997 ◽  
Vol 52 (1-2) ◽  
pp. 97-104 ◽  
Author(s):  
Daniela Selmer ◽  
Reingard Senekowitsch-Schmidtke ◽  
W. Schneider ◽  
E. F. Elstner

Abstract Specific and unspecific binding and uptake (internalization) by macrophages of 125iodine -labelled, copper-oxidized human low density lipoprotein is differently influenced by the anti­ oxidants α-tocopherol (α-Toc), probucol (Prob), pyridoxal-5'-phosphate (PP) and the magnesium-pyridoxal-5'-phosphate glutamate complex (MPPG). Binding as well as internalization, mediated by the so-called "scavenger receptor" is lower in the presence of MPPG whereas both specific binding and internalization are enhanced. The comparison of the effects in vitro allows a rating of the potentially anti-atherogenic and thus protective effects of the tested substances as follows: MPPG > PP > α-Toc > Prob.


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