Modification of low density lipoprotein by desialylation causes lipid accumulation in cultured cells: Discovery of desialylated lipoprotein with altered cellular metabolism in the blood of atherosclerotic patients

1989 ◽  
Vol 162 (1) ◽  
pp. 206-211 ◽  
Author(s):  
A.N. Orekhov ◽  
V.V. Tertov ◽  
D.N. Mukhin ◽  
I.A. Mikhailenko
2016 ◽  
Vol 62 (4) ◽  
pp. 391-402 ◽  
Author(s):  
V.N. Sukhorukov ◽  
V.P. Karagodin ◽  
A.N. Orekhov

One of the first manifestations of atherosclerosis is accumulation of extra- and intracellular cholesterol esters in the arterial intima. Formation of foam cells is considered as a trigger in the pathogenesis of atherosclerosis. Low density lipoprotein (LDL) circulating in human blood is the source of lipids accumulated in the arterial walls. This review considered features and role in atherogenesis different modified forms of LDL: oxidized, small dense, electronegative and especially desialylated LDL. Desialylated LDL of human blood plasma is capable to induce lipid accumulation in cultured cells and it is atherogenic. LDL possesses numerous alterations of protein, carbohydrate and lipid moieties and therefore can be termed multiple-modified LDL. Multiple modification of LDL occurs in human blood plasma and represents a cascade of successive changes in the lipoprotein particle: desialylation, loss of lipids, reduction in the particle size, increase of surface electronegative charge, etc. In addition to intracellular lipid accumulation, stimulatory effects of naturally occurring multiple-modified LDL on other processes involved in the development of atherosclerotic lesions, namely cell proliferation and fibrosis, were shown.


Author(s):  
Dean A. Handley ◽  
Cynthia M. Arbeeny ◽  
Larry D. Witte

Low density lipoproteins (LDL) are the major cholesterol carrying particles in the blood. Using cultured cells, it has been shown that LDL particles interact with specific surface receptors and are internalized via a coated pit-coated vesicle pathway for lysosomal catabolism. This (Pathway has been visualized using LDL labeled to ferritin or colloidal gold. It is now recognized that certain lysomotropic agents, such as chloroquine, inhibit lysosomal enzymes that degrade protein and cholesterol esters. By interrupting cholesterol ester hydrolysis, chloroquine treatment results in lysosomal accumulation of cholesterol esters from internalized LDL. Using LDL conjugated to colloidal gold, we have examined the ultrastructural effects of chloroquine on lipoprotein uptake by normal cultured fibroblasts.


2009 ◽  
Vol 125 (11) ◽  
pp. 2505-2510 ◽  
Author(s):  
Michihiro Mutoh ◽  
Masami Komiya ◽  
Naoya Teraoka ◽  
Toshiya Ueno ◽  
Mami Takahashi ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Hiroe Go ◽  
Jin Ah Ryuk ◽  
Hye Won Lee ◽  
In Sil Park ◽  
Ki-Jung Kil ◽  
...  

The present study was conducted to investigate the effect of Sagunja-tang on the lipid related disease in a rat model of menopausal hyperlipidemia and lipid accumulation in methyl-β-cyclodextrin-induced HepG2 cells. Inin vivostudy using menopausal hyperlipidemia rats, Sagunja-tang reduced retroperitoneal and perirenal fat, serum lipids, atherogenic index, cardiac risk factor, media thickness, and nonalcoholic steatohepatitis score, when compared to menopausal hyperlipidemia control rats. In HepG2 cells, Sagunja-tang significantly decreased the lipid accumulation, total cholesterol levels, and low-density/very-low-density lipoprotein levels. Moreover, Sagunja-tang reversed the methyl-β-cyclodextrin-induced decrease in the protein levels of critical molecule involved in cholesterol synthesis, sterol regulatory element binding protein-2, and low-density lipoprotein receptor and inhibited protein levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase as well as activity. Phosphorylation level of AMP-activated protein kinase was stimulated by Sagunja-tang. These results suggest that Sagunja-tang has effect on inhibiting hepatic lipid accumulation through regulation of cholesterol synthesis and AMPK activityin vitro. These observations support the idea that Sagunja-tang is bioavailable bothin vivoandin vitroand could be developed as a preventive and therapeutic agent of hyperlipidemia in postmenopausal females.


2018 ◽  
Vol 19 (12) ◽  
pp. 3903 ◽  
Author(s):  
Xiaofei Zhu ◽  
Jingyi Yang ◽  
Wenjuan Zhu ◽  
Xiaoxiao Yin ◽  
Beibei Yang ◽  
...  

The natural compound berberine has been reported to exhibit anti-diabetic activity and to improve disordered lipid metabolism. In our previous study, we found that such compounds upregulate expression of sirtuin 1—a key molecule in caloric restriction, it is, therefore, of great interest to examine the lipid-lowering activity of berberine in combination with a sirtuin 1 activator resveratrol. Our results showed that combination of berberine with resveratrol had enhanced hypolipidemic effects in high fat diet-induced mice and was able to decrease the lipid accumulation in adipocytes to a level significantly lower than that in monotherapies. In the high fat diet-induced hyperlipidemic mice, combination of berberine (25 mg/kg/day, oral) with resveratrol (20 mg/kg/day, oral) reduced serum total cholesterol by 27.4% ± 2.2%, and low-density lipoprotein-cholesterol by 31.6% ± 3.2%, which was more effective than that of the resveratrol (8.4% ± 2.3%, 6.6% ± 2.1%) or berberine (10.5% ± 1.95%, 9.8% ± 2.58%) monotherapy (p < 0.05 for both). In 3T3-L1 adipocytes, the treatment of 12 µmol/L or 20 µmol/L berberine combined with 25 µmol/L resveratrol showed a more significant inhibition of lipid accumulation observed by Oil red O stain compared with individual compounds. Moreover, resveratrol could increase the amount of intracellular berberine in hepatic L02 cells. In addition, the combination of berberine with resveratrol significantly increases the low-density-lipoprotein receptor expression in HepG2 cells to a level about one-fold higher in comparison to individual compound. These results implied that the enhanced effect of the combination of berberine with resveratrol on lipid-lowering may be associated with upregulation of low-density-lipoprotein receptor, and could be an effective therapy for hyperlipidemia in some obese-associated disease, such as type II diabetes and metabolic syndrome.


2015 ◽  
Vol 308 (12) ◽  
pp. E1140-E1148 ◽  
Author(s):  
Yang Zhang ◽  
Kun Ling Ma ◽  
Jing Liu ◽  
Yu Wu ◽  
Ze Bo Hu ◽  
...  

Dyslipidemia plays crucial roles in the progression of diabetic nephropathy (DN). This study investigated the effects of high glucose on lipid accumulation in podocytes and explored its underlying mechanisms. Male db/m and db/db mice were fed a normal chow diet for 8 wk. Immortalised mouse podocytes were treated with or without high glucose for 24 h. The changes to the morphology and ultramicrostructures of the kidneys in mice were examined using pathological staining and electron microscopy. Intracellular lipid accumulation was evaluated by Oil Red O staining and a free cholesterol quantitative assay. The expressions of the molecules involved in low-density lipoprotein receptor (LDLr) pathway and podocyte injury were examined using immunofluorescent staining, real-time PCR, and Western blot. There were increased levels of plasma lipid, serum creatinine, and proteinuria in db/db mice compared with db/m mice. Moreover, there was significant mesangial matrix expansion, basement membrane thickening, podocyte foot process effacement, and phenotypic alteration in the db/db group. Additionally, lipid accumulation in the kidneys of db/db mice was increased due to increased protein expressions of LDLr, sterol regulatory element-binding protein (SREBP) cleavage-activating protein, and SREBP-2. These effects were further confirmed by in vitro studies. Interestingly, the treatment with LDLr siRNA inhibited lipid accumulation in podocytes and decreased the protein expression of molecules associated with phenotypic alteration in podocytes. High glucose disrupted LDLr feedback regulation in podocytes, which may cause intracellular lipid accumulation and alteration of podocyte phenotype, thereby accelerating DN progression.


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