A comparison of oxidized LDL-induced collagen secretion by graft and aortic SMCs: role of PDGF

Smooth muscle cells (SMCs) from prosthetic vascular grafts constitutively secrete higher levels of collagen than aortic SMCs. Lipid oxidation products accumulate in grafts, and we postulated that they stimulate SMC production of collagen. The effect of oxidized low-density lipoprotein (oxLDL) on type I collagen secretion by aortic and graft SMCs was compared. SMCs isolated from the canine thoracic aorta or Dacron thoracoabdominal grafts ( n = 10) were incubated with native LDL or oxLDL (0–400 μg cholesterol/ml) for 72 h. Type I collagen in the conditioned medium was measured by ELISA. OxLDL increased collagen production by graft SMCs from 4.1 ± 0.3 to 11.0 ± 0.4 ng/μg DNA and by aortic SMCs from 2.3 ± 0.1 to 3.5 ± 0.2 ng/μg DNA. Native LDL had little effect. LY-83583, a superoxide generator, stimulated a dramatic increase in collagen secretion by graft SMCs and a smaller but significant elevation by aortic SMCs. OxLDL has been shown to increase PDGF production by graft SMCs, and PDGF can stimulate collagen production. Anti-PDGF antibody inhibited the increase in collagen production by graft SMCs that was stimulated by oxLDL, implicating PDGF as one mechanism of oxLDL-induced collagen production. Lipid oxidation products that accumulate in prosthetic vascular grafts can cause an oxidative stress that stimulates PDGF production by graft SMCs that in turn stimulates collagen production, contributing to the progression of intimal hyperplasia.

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Differential PDGF secretion by graft and aortic SMC in response to oxidized LDL

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00060.2002 ◽

2002 ◽

Vol 283 (2) ◽

pp. H725-H732 ◽

Cited By ~ 11

Author(s):

Afaf Absood ◽

Akira Furutani ◽

Tsutomu Kawamura ◽

Linda M. Graham

Keyword(s):

Oxidative Stress ◽

Lipid Oxidation ◽

Oxidized Ldl ◽

Low Density Lipoprotein ◽

Vascular Grafts ◽

Density Lipoprotein ◽

Oxidation Products ◽

Enzyme Linked Immunosorbent Assay ◽

Oxidized Low Density Lipoprotein ◽

Lipid Oxidation Products

Smooth muscle cells (SMC) from prosthetic vascular grafts constitutively secrete higher levels of platelet-derived growth factor-AA (PDGF-AA) than aortic SMC. Lipid oxidation products accumulate in grafts and may stimulate PDGF production. The effect of oxidized low-density lipoprotein (oxLDL) on PDGF-AA secretion by aortic and graft SMC was compared. SMC isolated from canine thoracic aorta or Dacron thoracoabdominal grafts ( n = 10) were incubated with native LDL or oxLDL (0–400 μg/ml) for 72 h. PDGF-AA in the conditioned medium was measured with enzyme-linked immunosorbent assay. OxLDL increased PDGF-AA production by graft SMC from 78 ± 2 to 256 ± 16 pg PDGF/μg DNA and aortic SMC from 21 ± 1 to 40 ± 2 pg PDGF/μg DNA. Native LDL had no effect. N-acetylcysteine inhibited oxLDL-induced PDGF increase. Both superoxide and H2O2 stimulated PDGF secretion by graft SMC had little effect on aortic SMC. Our results suggest that PDGF production by graft (synthetic) SMC is more sensitive to stimulation by oxidative stress than aortic (contractile) SMC. Lipid oxidation products that accumulate in prosthetic vascular grafts can cause an oxidative stress, which stimulates PDGF production by graft SMC. PDGF can induce migration of aortic SMC onto the graft, contributing to the development of intimal hyperplasia.

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Actin Polymerization in Macrophages in Response to Oxidized LDL and Apoptotic Cells: Role of 12/15-Lipoxygenase and Phosphoinositide 3-Kinase

Molecular Biology of the Cell ◽

10.1091/mbc.e03-02-0063 ◽

2003 ◽

Vol 14 (10) ◽

pp. 4196-4206 ◽

Cited By ~ 44

Author(s):

Yury I. Miller ◽

Dorothy S. Worrall ◽

Colin D. Funk ◽

James R. Feramisco ◽

Joseph L. Witztum

Keyword(s):

Cell Membrane ◽

Actin Polymerization ◽

Oxidized Ldl ◽

Low Density Lipoprotein ◽

Specific Inhibitor ◽

Density Lipoprotein ◽

Oxidation Products ◽

Apoptotic Cells ◽

Lipid Oxidation Products ◽

Phosphoinositide 3 Kinase

Formation of filamentous F-actin drives many cellular processes, including phagocytosis and cell spreading. We have recently reported that mouse macrophage 12/15-lipoxygenase (12/15-LO) activity promotes F-actin formation in filopodia during phagocytosis of apoptotic cells. Oxidized low-density lipoprotein (OxLDL) also stimulates robust F-actin formation and spreading of macrophages. However, unlike apoptotic cells, OxLDL did not cause specific translocation of 12/15-LO to the cell membrane, neither in macrophages nor in GFP-15LO–transfected COS-7 cells. Moreover, inhibition of 12/15-LO activity in macrophages by a specific inhibitor or by 12/15-LO gene disruption did not affect OxLDL-induced actin polymerization. Among LDL modifications modeling OxLDL, LDL modified by incubation with 15LO-overexpressing fibroblasts was as active in eliciting F-actin response as was OxLDL. This LDL modification is well known to produce minimally modified LDL (mmLDL), which is bioactive and carries lipid oxidation products similar to those produced by 12/15-LO catalysis. MmLDL activated phosphoinositide 3-kinase (PI3K), and PI3K inhibitors abolished mmLDL-induced macrophage spreading. We hypothesize that OxLDL and mmLDL may contribute oxidized lipids to the macrophage cell membrane and thereby mimic intracellular 12/15-LO activity, which leads to uncontrolled actin polymerization and dramatic cytoskeletal changes in macrophages.

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Modification of Delipidated Apoprotein B of Low Density Lipoprotein by Lipid Oxidation Products in Relation to Macrophage Scavenger Receptor Binding.

Biological and Pharmaceutical Bulletin ◽

10.1248/bpb.17.51 ◽

1994 ◽

Vol 17 (1) ◽

pp. 51-57 ◽

Cited By ~ 22

Author(s):

Manuel ALAIZ ◽

Masatoshi BEPPU ◽

Kenji OHISHI ◽

Kiyomi KIKUGAWA

Keyword(s):

Lipid Oxidation ◽

Receptor Binding ◽

Low Density Lipoprotein ◽

Scavenger Receptor ◽

Density Lipoprotein ◽

Oxidation Products ◽

Low Density ◽

Macrophage Scavenger Receptor ◽

Lipid Oxidation Products ◽

Apoprotein B

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Direct Separation of the Diastereomers of Cholesterol Ester Hydroperoxide Using LC-MS/MS to Evaluate Enzymatic Lipid Oxidation

Symmetry ◽

10.3390/sym12071127 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1127

Author(s):

Junya Ito ◽

Naoki Shimizu ◽

Shunji Kato ◽

Yusuke Ogura ◽

Kiyotaka Nakagawa

Keyword(s):

Lipid Oxidation ◽

Cholesterol Ester ◽

Mobile Phase ◽

Oxidized Ldl ◽

Oxidation Products ◽

Enzymatic Oxidation ◽

Column Temperature ◽

Lipid Oxidation Products ◽

Oxidation Mechanisms

Cholesterol ester hydroperoxide (CEOOH) is one of the main lipid oxidation products contained in oxidized low-density lipoprotein (LDL). Previous studies suggest that CEOOH in oxidized LDL is closely related to several diseases. Of the oxidation mechanisms of cholesterol ester (CE) in vivo, it has been suggested that enzymatic oxidation induced by lipoxygenase (LOX) plays an important role. Thus, we attempted to develop a method that can evaluate the enzymatic oxidation of CE via the diastereoselective separation of CEOOH bearing 13RS-9Z,11E-hydroperoxy-octadecadienoic acid (13(RS)-HPODE CE). Firstly, we synthesized the standard of 13(RS)-HPODE CE. Using this standard, the screening of analytical conditions (i.e., column, mobile phase, and column temperature) was conducted, and separation of the diastereomers of 13(RS)-HPODE CE was achieved. The diastereoselective separation of 13(RS)-HPODE CE was also confirmed by LC-MS/MS. The developed method (column, CHIRALPAK IB N-3; mobile phase, hexane:ethanol (100:1, v/v); column temperature, 0 °C) can distinguish between enzymatic oxidation and other oxidation mechanisms of CE. Thus, the method can be expected to provide a greater understanding of the biochemical oxidation mechanisms in vivo. Such information will be essential to further elucidate the involvement of CEOOH in various diseases.

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