Low Density Lipoprotein Receptor-related Protein Is Required for Macrophage-mediated Oxidation of Low Density Lipoprotein by 12/15-Lipoxygenase

Xu, Wanpeng; Takahashi, Yoshitaka; Sakashita, Toshiki; Iwasaki, Takashi; Hashimoto, Hiroaki; Yoshimoto, Tanihiro

doi:10.1074/jbc.m105093200

Cited by 30 publications

(28 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3). 12/15-Lipoxygenase-expressing J774A.1 cells have both LRP and the LDL receptor, although the expression level of the LDL receptor is low (13). In contrast, normal macrophages express high level of LRP but do not express the LDL receptor (26,27).…”

Section: Membrane Translocation Of 12/15-lipoxygenase By Ldl-12/mentioning

confidence: 99%

“…An anti-LDL receptor antibody was raised as described and purified to IgG using protein A-Sepharose (13). Human LDL was prepared from healthy volunteers and dialyzed against phosphate-buffered saline at 4°C for 24 h before each experiment as described previously (12,13). A murine macrophage-like cell line J774A.1 was kindly provided by Dr. Y. Saeki of Shiga University of Medical Science.…”

Section: Methodsmentioning

confidence: 99%

“…An antiserum against 12/15-lipoxygenase was raised using purified recombinant rat pineal 12-lipoxygenase as an antigen as described previously (17). An anti-LDL receptor antibody was raised as described and purified to IgG using protein A-Sepharose (13). Human LDL was prepared from healthy volunteers and dialyzed against phosphate-buffered saline at 4°C for 24 h before each experiment as described previously (12,13).…”

Section: Methodsmentioning

confidence: 99%

“…LRP Mediates the Translocation of 12/15-Lipoxygenase-We previously reported the essential requirement of LRP for the cell-mediated oxidation of LDL in macrophages (13). To examine whether the LRP is also involved in the translocation of the enzyme, we employed an anti-LRP antibody that blocked the binding of LDL to LRP (19).…”

Section: Membrane Translocation Of 12/15-lipoxygenase By Ldl-12/mentioning

confidence: 99%

“…However, the mechanism of extracellular LDL oxidation by intracellular 12/15-lipoxygenase has not been established. Recently, we revealed that the lipoxygenase-mediated LDL oxidation by macrophages required the binding of LDL to LDL receptor-related protein (LRP) but not to the LDL receptor, both of which are expressed on the surface of J774A.1 cells and are capable of binding native LDL (13).…”

mentioning

confidence: 99%

See 4 more Smart Citations

Low Density Lipoprotein Receptor-related Protein-mediated Membrane Translocation of 12/15-Lipoxygenase Is Required for Oxidation of Low Density Lipoprotein by Macrophages

Zhu

Takahashi

et al. 2003

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Oxidation of low density lipoprotein (LDL) is the key step for the development of atherosclerosis. The 12/15-lipoxygenase expressed in macrophages is capable of oxygenating linoleic acid esterified to cholesterol in the LDL particle, and thus this enzyme is presumed to initiate LDL oxidation. We recently reported that LDL receptor-related protein (LRP) was required for the enzyme-mediated LDL oxidation by macrophages and suggested the selective uptake of cholesterol ester from LDL to the plasma membrane (Xu, W., Takahashi, Y., Sakashita, T., Iwasaki, T., Hattori, H., and Yoshimoto. T. (2001) J. Biol. Chem. 276, 36454 -36459). To elucidate precise mechanisms of lipoxygenase-mediated LDL oxidation, we investigated the intracellular localization of 12/15-lipoxygenase. The 12/15-lipoxygenase was predominantly detected in cytosol of resting peritoneal macrophages and of macrophage-like J774A.1 cells permanently transfected with the cDNA for the enzyme. When the cells were treated with LDL and subjected to subcellular fractionation, the 12/15-lipoxygenase was detected in the membranes with a concomitant decrease in cytosol as shown by Western blot analysis. The levels of the enzyme associated with the membrane reached maximum in 15 min after LDL addition and then decreased. However, the enzymatic activity of 12/15-lipoxygenase in the membrane fraction was very weak even after LDL treatment. This fact supports the suicide inactivation of the enzyme by the oxygenation of cholesterol ester transferred from the LDL particle to the plasma membrane. Immunohistochemical analysis using an antibody against 12/15-lipoxygenase revealed that the plasma membrane was the major site of the enzyme translocation by the LDL treatment. LDL-dependent 12/ 15-lipoxygenase translocation was inhibited by a blocking antibody against LRP. Furthermore, an enzyme translocation inhibitor, L655238, inhibited the LDL oxidation caused by the 12/15-lipoxygenase. We propose that cholesterol ester selectively transferred from the LDL particle to the plasma membrane via LRP is oxygenated by 12/15-lipoxygenase translocated to this membrane.12/15-Lipoxygenase is a member of the lipoxygenase family, which incorporates one molecule of oxygen in regiospecific and stereospecific manners to unsaturated fatty acids such as arachidonic and linoleic acids (1-4). The enzyme consists of leukocyte-type 12-lipoxygenase found in rats, mice, cows, and pigs, and reticulocyte-type 15-lipoxygenase (15-lipoxygenase-1) expressed in humans and rabbits, oxygenating the position 12 and 15 of arachidonic acid, respectively (5). The notable feature of the 12/15-lipoxygenase is that the enzyme directly oxygenates not only free fatty acids but also complex substrates such as phospholipids, cholesterol ester, and the cholesterol ester present in the low density lipoprotein (LDL) 1 particle (1-4). Oxidation of LDL is the first key step for the development of atherosclerosis (6, 7), and the roles of the 12/15-lipoxygenase in the process of LDL oxidation and the progress of atherogene...

show abstract

Section: Membrane Translocation Of 12/15-lipoxygenase By Ldl-12/mentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Membrane Translocation Of 12/15-lipoxygenase By Ldl-12/mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Low Density Lipoprotein Receptor-related Protein-mediated Membrane Translocation of 12/15-Lipoxygenase Is Required for Oxidation of Low Density Lipoprotein by Macrophages

Zhu

Takahashi

et al. 2003

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

The LDL receptor-related protein (LRP1/A2MR) and coronary atherosclerosis - novel genomic variants and functional consequences

Schulz¹,

Schagdarsurengin²,

Greiser³

et al. 2002

Hum. Mutat.

View full text Add to dashboard Cite

The LDL receptor-related protein/alpha 2-macroglobulin receptor (LRP1/A2MR) is a multifunctional cell-surface glycoprotein that endocytoses several structurally and functionally distinct ligands. In clinical studies different genomic variants of the LRP1/A2MR and its role in the development of degenerative diseases like atherosclerosis or Alzheimer's disease were studied. We screened for novel genomic variants of LRP1/A2MR and investigated the importance of these variants in 214 coronary patients suffering from myocardial infarction as well as in 224 healthy controls. We detected a novel C>G polymorphism at position -25 in the functionally important promoter region of LRP1/A2MR. This polymorphism (c.1-25C>G) leads to the creation of a new GC-box, recognized by the constitutively expressed SP 1 transcription factor. Investigating the LRP1/A2MR gene expression with respect to this polymorphism, carriers of the mutant G-allele were found to have a higher mRNA expression level. A novel polymorphism in exon 22 (c.4012C>T), and two novel polymorphisms in intron 24 (IVS24+123C>A and IVS24+690G>A) associated with a previously described polymorphism in exon 61 (c.10249G>A), were related to the development of myocardial infarction. Two novel rare genetic variants of exon 88 (c.13933C>T) and intron 88 (IVS88+15G>A) were identified in four patients with severe coronary symptoms. However, the LRP1/A2MR gene expression was found to be independent of all identified novel genomic variants as well as other previously described changes (A217V, A775P, D2080N, D2632E, G4379S) except the promoter polymorphism.

show abstract

Aldosterone up‐regulates 12‐ and 15‐lipoxygenase expression and LDL oxidation in human vascular smooth muscle cells

Limor

Kaplan

Sharon

et al. 2009

J of Cellular Biochemistry

View full text Add to dashboard Cite

Several lines of evidence suggest that aldosterone excess may have detrimental effects in the cardiovascular system, independent of its interaction with the renal epithelial cells. Here we examined the possibility that aldosterone modulates 12- and/or 15-lipoxygenase (LO) expression/activity in human vascular smooth muscle cells (VSMC), in vitro, thereby potentially contributing to both vascular reactivity and atherogenesis. Following 24 h treatment of VSMC with aldosterone (1 nmol/L), there was a approximately 2-fold increase in the generation rate of 12 hydroxyeicosatetraenoic acid (12-HETE), 70% increase in platelet type 12-LO mRNA expression (P < 0.001) along with a approximately 3-fold increase in 12-LO protein expression, which were blocked by the mineralocorticoid receptor (MR) antagonists spironolactone (100 nmol/L) and eplerelone (100 nmol/ml). Additionally, aldosterone (1 nmol/L; 24 h) increased the production of 15-HETE (50%; P < 0.001) and the expression of 15-LO type 2 mRNA (50%; P < 0.05) (in VSMC). Aldosterone also increased the 12- and 15-LO type 2 mRNA expression in a line of human aortic smooth muscle cells (T/G HA-VSMC) (60% and 50%, respectively). Aldosterone-induced 12- and 15-LO type 2 mRNA expressions were blocked by the EGF-receptor antagonist AG 1478 and by the MAPK-kinase inhibitor UO126. Aldosterone-treated VSMC also showed increased LDL oxidation, (approximately 2-fold; P < 0.001), which was blocked by spironolactone. In conclusion, aldosterone increased 12- and 15-LO expression in human VSMC, in association with increased 12- and 15-HETE generation and enhanced LDL oxidation and may directly augment VSMC contractility, hypertrophy, and migration through 12-HETE and promote LDL oxidation via the pro-oxidative properties of these enzymes.

show abstract

Low Density Lipoprotein Receptor-related Protein Is Required for Macrophage-mediated Oxidation of Low Density Lipoprotein by 12/15-Lipoxygenase

Cited by 30 publications

References 52 publications

Low Density Lipoprotein Receptor-related Protein-mediated Membrane Translocation of 12/15-Lipoxygenase Is Required for Oxidation of Low Density Lipoprotein by Macrophages

Low Density Lipoprotein Receptor-related Protein-mediated Membrane Translocation of 12/15-Lipoxygenase Is Required for Oxidation of Low Density Lipoprotein by Macrophages

The LDL receptor-related protein (LRP1/A2MR) and coronary atherosclerosis - novel genomic variants and functional consequences

Aldosterone up‐regulates 12‐ and 15‐lipoxygenase expression and LDL oxidation in human vascular smooth muscle cells

Contact Info

Product

Resources

About