scholarly journals Stimulation of mast cells leads to cholesterol accumulation in macrophages in vitro by a mast cell granule-mediated uptake of low density lipoprotein.

1987 ◽  
Vol 84 (8) ◽  
pp. 2287-2291 ◽  
Author(s):  
J. O. Kokkonen ◽  
P. T. Kovanen
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Cell Granule ◽  
Low Density ◽  
Cholesterol Accumulation ◽  
Mast Cell Granule ◽  
Stimulation Of

scholarly journals Mast cell deficiency attenuates progression of atherosclerosis and hepatic steatosis in apolipoprotein E-null mice

2012 ◽  
Vol 302 (12) ◽  
pp. H2612-H2621 ◽  
Author(s):  
Donald D. Smith ◽  
Xiaoyu Tan ◽  
Vineesh V. Raveendran ◽  
Ossama Tawfik ◽  
Daniel J. Stechschulte ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Apolipoprotein E ◽  
Hepatic Steatosis ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Serum Levels ◽  
Low Density ◽  
High Fat ◽  
Progression Of Atherosclerosis

Mast cells are important cells of the immune system and are recognized as participants in the pathogenesis of atherosclerosis. In this study, we evaluated the role of mast cells on the progression of atherosclerosis and hepatic steatosis using the apolipoprotein E-deficient ( ApoE−/−) and ApoE−/−/mast cell-deficient ( KitW-sh/W-sh) mouse models maintained on a high-fat diet. The en face analyses of aortas showed a marked reduction in plaque coverage in ApoE−/−/KitW-sh/W-shcompared with ApoE−/−after a 6-mo regimen with no significant change noted after 3 mo. Quantification of intima/media thickness on hematoxylin and eosin-stained histological cross sections of the aortic arch revealed no significant difference between ApoE−/−and ApoE−/−/KitW-sh/W-shmice. The high-fat regimen did not induce atherosclerosis in either KitW-sh/W-shor wild-type mice. Mast cells with indications of degranulation were seen only in the aortic walls and heart of ApoE−/−mice. Compared with ApoE−/−mice, the serum levels of total cholesterol, low-density lipoprotein and high-density lipoprotein were decreased by 50% in ApoE−/−/KitW-sh/W-shmice, whereas no appreciable differences were noted in serum levels of triglycerides or very low density lipoprotein. ApoE−/−/KitW-sh/W-shmice developed significantly less hepatic steatosis than ApoE−/−mice after the 3-mo regimen. The analysis of Th1/Th2/Th17 cytokine profile in the sera revealed significant reduction of interleukin (IL)-6 and IL-10 in ApoE−/−/KitW-sh/W-shmice compared with ApoE−/−mice. The assessment of systemic generation of thromboxane A2(TXA2) and prostaglandin I2(PGI2) revealed significant decrease in the production of PGI2in ApoE−/−/KitW-sh/W-shmice with no change in TXA2. The decrease in PGI2production was found to be associated with reduced levels of cyclooxygenase-2 mRNA in the aortic tissues. A significant reduction in T-lymphocytes and macrophages was noted in the atheromas of the ApoE−/−/KitW-sh/W-shmice. These results demonstrate the direct involvement of mast cells in the progression of atherosclerosis and hepatic steatosis.

scholarly journals Low-density-lipoprotein binding by mast-cell granules. Demonstration of binding of apolipoprotein B to heparin proteoglycan of exocytosed granules

1987 ◽  
Vol 241 (2) ◽  
pp. 583-589 ◽  
Author(s):  
J O Kokkonen ◽  
P T Kovanen
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Major Protein ◽  
Low Density ◽  
Apo B ◽  
Apo E ◽  
Lipoprotein Binding ◽  
Positively Charged

To study the interaction between low-density lipoprotein (LDL) and granules from rat serosal mast cells in vitro, mast cells were stimulated with the degranulating agent 48/80 to induce exocytosis of the secretory granules. Subsequent incubation of the exocytosed granules with 125I-LDL resulted in binding of the labelled LDL to the granules. When increasing amounts of agent 48/80 were added to mast-cell suspensions, a dose-dependent release of granules was observed and a parallel increase in the amount of 125I-LDL bound to granules resulted. 125I-LDL bound to a single class of high-affinity binding sites on the granules. At saturation, 105 ng of LDL were bound per microgram of granule protein. The lipoprotein binding to mast-cell granules was apolipoprotein(apo)-B + E-specific. Thus 125I-LDL binding to the granules was effectively compared for by LDL (apo-B) or by dimyristoyl phosphatidylcholine vesicles containing apo-E, but not by high-density lipoprotein (HDL3) containing apo-AI as their major protein component. Neutralization by acetylation of the positively charged amino groups of apo-B of LDL or presence of a high ionic strength in the incubation medium prevented LDL from binding to the granules, indicating the presence of ionic interactions between the positively charged amino acids of LDL and negatively charged groups of the granules. It could be demonstrated that LDL bound to the negatively charged heparin proteoglycan of the granules. Thus treatment of granules with heparinase resulted in loss of their ability to bind LDL, and substances known to bind to heparin, such as Toluidine Blue, avidin, lipoprotein lipase, fibronectin and protamine, all effectively competed with LDL for binding to the granules. The results show that LDL is efficiently bound to the heparin proteoglycan component of mast-cell granules once the mast cells are stimulated to release their granules into the extracellular space.

scholarly journals Reductions of copper ion-mediated low-density lipoprotein (LDL) oxidations of trypsin inhibitors, the sweet potato root major proteins, and LDL binding capacities

2020 ◽  
Vol 61 (1) ◽  
Author(s):  
Yeh-Lin Lu ◽  
Chia-Jung Lee ◽  
Shyr-Yi Lin ◽  
Wen-Chi Hou
Keyword(s):  
Sweet Potato ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Trypsin Inhibitors ◽  
Water Soluble ◽  
Affinity Column ◽  
Low Density ◽  
Native Page

Abstract Background The root major proteins of sweet potato trypsin inhibitors (SPTIs) or named sporamin, estimated for 60 to 80% water-soluble proteins, exhibited many biological activities. The human low-density lipoprotein (LDL) showed to form in vivo complex with endogenous oxidized alpha-1-antitrypsin. Little is known concerning the interactions between SPTIs and LDL in vitro. Results The thiobarbituric-acid-reactive-substance (TBARS) assays were used to monitor 0.1 mM Cu2+-mediated low-density lipoprotein (LDL) oxidations during 24-h reactions with or without SPTIs additions. The protein stains in native PAGE gels were used to identify the bindings between native or reduced forms of SPTIs or soybean TIs and LDL, or oxidized LDL (oxLDL). It was found that the SPTIs additions showed to reduce LDL oxidations in the first 6-h and then gradually decreased the capacities of anti-LDL oxidations. The protein stains in native PAGE gels showed more intense LDL bands in the presence of SPTIs, and 0.5-h and 1-h reached the highest one. The SPTIs also bound to the oxLDL, and low pH condition (pH 2.0) might break the interactions revealed by HPLC. The LDL or oxLDL adsorbed onto self-prepared SPTIs-affinity column and some components were eluted by 0.2 M KCl (pH 2.0). The native or reduced SPTIs or soybean TIs showed different binding capacities toward LDL and oxLDL in vitro. Conclusion The SPTIs might be useful in developing functional foods as antioxidant and nutrient supplements, and the physiological roles of SPTIs-LDL and SPTIs-oxLDL complex in vivo will investigate further using animal models.

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