Human tribbles homologue 2 is expressed in unstable regions of carotid plaques and regulates macrophage IL-10 in vitro

2009 ◽  
Vol 116 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Jingti Deng ◽  
Christian H. James ◽  
Lisa Patel ◽  
Alberto Smith ◽  
Kevin G. Burnand ◽  
...  
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Human Monocyte ◽  
Interleukin 10 ◽  
Plaque Instability ◽  
Signalling Molecules ◽  
Atherosclerotic Lesions ◽  
Protein Kinase Signalling

Mammalian orthologues of the Drosophila tribbles protein (Trb1, Trb2 and Trb3) are a recently described family of signalling molecules that regulate gene expression by modulation of protein kinase signalling pathways. In the present study, a screen for mRNA species specifically regulated in vulnerable regions of human atherosclerotic plaque demonstrated the up-regulation of both Trb1 and Trb2, the latter by more than 8-fold. In vitro experiments in primary human monocyte-derived macrophages showed that Trb2 expression was up-regulated by treatment with oxidized LDL (low-density lipoprotein), and that expression of recombinant Trb2 specifically reduced macrophage levels of IL-10 (interleukin-10) mRNA. Our results thus identify Trb2 as a highly regulated gene in vulnerable atherosclerotic lesions, and demonstrate inhibition of macrophage IL-10 biosynthesis as a potential pro-inflammatory consequence of high Trb2 expression, which may contribute to plaque instability.

scholarly journals Development of Capture Assays for Different Modifications of Human Low-Density Lipoprotein

2005 ◽  
Vol 12 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Gabriel Virella ◽  
M. Brooks Derrick ◽  
Virginia Pate ◽  
Charlyne Chassereau ◽  
Suzanne R. Thorpe ◽  
...  
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Gas Chromatography Mass Spectrometry ◽  
Low Density ◽  
Modified Ldl ◽  
Capture Assay ◽  
Carboxymethyl Lysine

ABSTRACT Antibodies to malondialdehyde (MDA)-modified low-density lipoprotein (LDL), copper-oxidized LDL (oxLDL), N ε(carboxymethyl) lysine (CML)-modified LDL, and advanced glycosylation end product (AGE)-modified LDL were obtained by immunization of rabbits with in vitro-modified human LDL preparations. After absorption of apolipoprotein B (ApoB) antibodies, we obtained antibodies specific for each modified lipoprotein with unique patterns of reactivity. MDA-LDL antibodies reacted strongly with MDA-LDL and also with oxLDL. CML-LDL antibodies reacted strongly with CML-LDL and also AGE-LDL. oxLDL antibodies reacted with oxLDL but not with MDA-LDL, and AGE-LDL antibodies reacted with AGE-LDL but not with CML-LDL. Capture assays were set with each antiserum, and we tested their ability to capture ApoB-containing lipoproteins isolated from precipitated immune complexes (IC) and from the supernatants remaining after IC precipitation (free lipoproteins). All antibodies captured lipoproteins contained in IC more effectively than free lipoproteins. Analysis of lipoproteins in IC by gas chromatography-mass spectrometry showed that they contained MDA-LDL and CML-LDL in significantly higher concentrations than free lipoproteins. A significant correlation (r = 0.706, P < 0.019) was obtained between the MDA concentrations determined by chemical analysis and by the capture assay of lipoproteins present in IC. In conclusion, we have developed capture assays for different LDL modifications in human ApoB/E lipoprotein-rich fractions isolated from precipitated IC. This approach obviates the interference of IC in previously reported modified LDL assays and allows determination of the degree of modification of LDL with greater accuracy.

Abstract 512: The Long Non-coding Rna MIAT Regulates Smooth Muscle Cell Proliferation and Macrophage Activity in Advanced Atherosclerotic Lesions

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Yuhuang Li ◽  
Hong Jin ◽  
Ljubica Perisic ◽  
Ekaterina Chernogubova ◽  
Alexandra Bäcklund ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Oxidized Ldl ◽  
In Silico Analysis ◽  
Human Monocyte ◽  
Carotid Plaques ◽  
Knock Down ◽  
Plaque Stability ◽  
Atherosclerotic Lesions ◽  
Markers Of Inflammation

Background: Long noncoding RNAs (lncRNAs) have emerged as critical epigenetic regulators in various biological processes and diseases. Here we sought to identify and functionally characterize the lncRNA MIAT as a novel regulator in atherosclerotic plaque stability. Methods and results: We profiled RNA transcript expression in patients with advanced atherosclerotic lesions from the Biobank of Karolinska Endarterectomies (BiKE). By microarray analysis, lncRNA MIAT was identified as one of the most highly up-regulated non-coding RNAs in carotid plaques compared to iliac artery controls, which was confirmed by qRT-PCR and in situ hybridization. Additional in silico analysis indicated a substantial positive correlation of MIAT with markers of inflammation, apoptosis and matrix degradation in carotid plaques. Experimental knock-down of MIAT, utilizing site-specific antisense oligonucleotides (LNA-GapmeRs) not only markedly decreased proliferation and migration rates of cultured human carotid artery smooth muscle cells (hCASMCs), but also increased their levels of apoptosis. In addition, MIAT inhibition significantly impaired oxidized LDL (oxLDL) uptake of murine peritoneal as well as human monocyte-differentiated macrophages in vitro. In contrast, induction of MIAT expression by lipoprotein-a (LPa) treatment, displayed the opposite effect. Conditioned medium from macrophage cultures after MIAT knock-down substantially decreased hCASMC proliferation, indicating a potential involvement of MIAT in macrophage-SMC interactions during advanced stages of atherosclerosis. Conclusion: The lncRNA MIAT is a novel regulator of cellular processes in atherosclerosis and plaque stability, which influences SMC proliferation and apoptosis and interacts with disease-triggering macrophages.

scholarly journals Treatment of macrophages with oxidized low-density lipoprotein increases their intracellular glutathione content

1991 ◽  
Vol 278 (2) ◽  
pp. 429-434 ◽  
Author(s):  
V M Darley-Usmar ◽  
A Severn ◽  
V J O'Leary ◽  
M Rogers
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Human Monocyte ◽  
Cell Types ◽  
Oxidative Modification ◽  
Glutathione Depletion ◽  
Lipid Phase ◽  
Low Density ◽  
Oxidized Low Density Lipoprotein

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.

Vascular responses and ion exchange in diabetes: Authors' reply

1992 ◽  
Vol 82 (3) ◽  
pp. 339-339
Author(s):  
J. M. Ritter ◽  
G. C. Viberti
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Large Body ◽  
Plasma Lipid ◽  
Density Lipoprotein ◽  
High Plasma ◽  
Diabetic Patients ◽  
Vascular Sensitivity

1. Na+/Li+ countertransport is not a gold standard, or indeed any other kind of standard. It is a measure of the activity of one particular cation exchanger. 2. There is a large body of literature regarding the effects of oxidized low-density lipoprotein (LDL) in experimental animals and in vitro. Whether abnormal oxidized LDL or one of many other possible mechanisms underlies the inverse relationship that we observed between vascular sensitivity in vivo to nitroprusside or carbachol with erythrocyte Na+/Li+ countertransport in diabetic patients remains to be seen. 3. We caution against post hoc subgroup analysis (smokers versus non-smokers, low versus high plasma lipid levels, etc.) in studies of this size.

Gemfibrozil metabolite inhibits in vitro low-density lipoprotein (LDL) oxidation and diminishes cytotoxicity induced by oxidized LDL

Metabolism ◽  
2000 ◽  
Vol 49 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Mitsunobu Kawamura ◽  
Shigeru Miyazaki ◽  
Tamio Teramoto ◽  
Keiko Ashidate ◽  
Hisako Thoda ◽  
...  
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Ldl Oxidation ◽  
Low Density

scholarly journals Oxidized low density lipoprotein inhibits the migration of aortic endothelial cells in vitro.

1993 ◽  
Vol 120 (4) ◽  
pp. 1011-1019 ◽  
Author(s):  
G Murugesan ◽  
G M Chisolm ◽  
P L Fox
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Lipid Hydroperoxide ◽  
Density Lipoprotein ◽  
Low Density ◽  
Dependent Manner ◽  
Oxidized Low Density Lipoprotein ◽  
Inhibitor Molecule ◽  
Healing Response

Endothelial cell (EC) migration is a critical and initiating event in the formation of new blood vessels and in the repair of injured vessels. Compelling evidence suggests that oxidized low density lipoprotein (LDL) is present in atherosclerotic lesions, but its role in lesion formation has not been defined. We have examined the role of oxidized LDL in regulating the wound-healing response of vascular EC in vitro. Confluent cultures of bovine aortic EC were "wounded" with a razor, and migration was measured after 18 to 24 h as the number of cells moving into the wounded area and the mean distance of cells from the wound edge. Oxidized LDL markedly reduced migration in a concentration- and oxidation-dependent manner. Native LDL or oxidized LDL with a thiobarbituric acid (TBA) reactivity &lt; 5 nmol malondialdehyde equivalents/mg cholesterol was not inhibitory; however, oxidized LDL with a TBA reactivity of 8-12 inhibited migration by 75-100%. Inhibition was half-maximal at 250-300 micrograms cholesterol/ml and nearly complete at 350-400 micrograms/ml. The antimigratory activity was not due to cell death since it was completely reversed 16 h after removal of the lipoprotein. The inhibitor molecule was shown to be a lipid; organic solvent extracts of oxidized LDL inhibited migration to nearly the same extent as the intact particle. When LDL was variably oxidized by dialysis against FeSO4 or CuSO4, or by UV irradiation, the inhibitory activity correlated with TBA reactivity and total lipid peroxides, but not with electrophoretic mobility or fluorescence (360 ex/430 em). This indicates that a lipid hydroperoxide may be the active species. These results suggest the possibility that oxidized LDL may limit the healing response of the endothelium after injury.

scholarly journals Scavenger Receptors Class A-I/II and CD36 Are the Principal Receptors Responsible for the Uptake of Modified Low Density Lipoprotein Leading to Lipid Loading in Macrophages

2002 ◽  
Vol 277 (51) ◽  
pp. 49982-49988 ◽  
Author(s):  
Vidya V. Kunjathoor ◽  
Maria Febbraio ◽  
Eugene A. Podrez ◽  
Kathryn J. Moore ◽  
Lorna Andersson ◽  
...  
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Gas Chromatography Mass Spectrometry ◽  
Scavenger Receptors ◽  
Low Density ◽  
Lipid Uptake ◽  
Modified Ldl ◽  
Ldl Uptake

Modification of low density lipoprotein (LDL) can result in the avid uptake of these lipoproteins via a family of macrophage transmembrane proteins referred to as scavenger receptors (SRs). The genetic inactivation of either of two SR family members, SR-A or CD36, has been shown previously to reduce oxidized LDL uptakein vitroand atherosclerotic lesions in mice. Several other SRs are reported to bind modified LDL, but their contribution to macrophage lipid accumulation is uncertain. We generated mice lacking both SR-A and CD36 to determine their combined impact on macrophage lipid uptake and to assess the contribution of other SRs to this process. We show that SR-A and CD36 account for 75–90% of degradation of LDL modified by acetylation or oxidation. Cholesteryl ester derived from modified lipoproteins fails to accumulate in macrophages taken from the double null mice, as assessed by histochemistry and gas chromatography-mass spectrometry. These results demonstrate that SR-A and CD36 are responsible for the preponderance of modified LDL uptake in macrophages and that other scavenger receptors do not compensate for their absence.

In vitro glycated low-density lipoprotein interaction with human monocyte-derived macrophages

1992 ◽  
Vol 143 (1) ◽  
pp. 17-23 ◽  
Author(s):  
A. Gugliucci Creriche ◽  
S. Dumont ◽  
J.C. Siffert ◽  
A.J.C. Stahl
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Human Monocyte ◽  
Low Density

scholarly journals Oleacein and Foam Cell Formation in Human Monocyte-Derived Macrophages: A Potential Strategy against Early and Advanced Atherosclerotic Lesions

2020 ◽  
Vol 13 (4) ◽  
pp. 64
Author(s):  
Agnieszka Filipek ◽  
Tomasz P. Mikołajczyk ◽  
Tomasz J. Guzik ◽  
Marek Naruszewicz
Keyword(s):  
Flow Cytometry ◽  
Foam Cell ◽  
Low Density Lipoprotein ◽  
Cell Formation ◽  
Density Lipoprotein ◽  
Human Monocyte ◽  
Foam Cell Formation ◽  
Low Density ◽  
Oxidized Low Density Lipoprotein ◽  
Atherosclerotic Lesions

Background: Oleacein is a secoiridoid group polyphenol found mostly in Olea europea L. and Ligustrum vulgare L. (Oleaceae). The aim of the present study was to investigate a potential role of oleacein in prevention of the foam cell formation. Materials and Methods: Oleacein was isolated from Ligustrum vulgare leaves. Human monocyte-derived macrophages were obtained from monocytes cultured with Granulocyte-macrophage colony-stimulating factor (GM-CSF). Then, cells were incubated with 20 μM or 50 μM of oleacein and with oxidized low-density lipoprotein (oxLDL) (50 μg/mL). Visualization of lipid deposition within macrophages was carried out using Oil-Red-O. Expression of CD36, Scavenger receptor A1 (SRA1) and Lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) was determined by Reverse transcription polymerase chain reaction (RT-PCR) and by flow cytometry. Apoptosis was determined by flow cytometry using Annexin V assay. STAT3 and Acyl-coenzyme A: cholesterol acyltransferase type 1 (ACAT1) levels were determined by ELISA. P-STAT3, P-JAK1, P-JAK2 expressions were determined by Western blot (WB). Results: Oleacein in dose-dependent manner significantly reduced lipid deposits in macrophages as well as their expression of selected scavenger receptors. The highest decrease of expression was found for CD36 and SRA1 receptors, from above 20% to more than 75% compared to oxLDL and the lowest for LOX-1 receptor, from approx. 8% to approx. 25% compared to oxLDL-stimulated macrophages. Oleacein significantly reduced (2.5-fold) early apoptosis of oxLDL-stimulated macrophages. Moreover, oleacein significantly increased the protein expression of JAK/STAT3 pathway and had no effect on ACAT1 level. Conclusions: Our study demonstrates, for the first time, that oleacein inhibits foam cell formation in human monocyte-derived macrophages and thus can be a valuable tool in the prevention of early and advanced atherosclerotic lesions.

scholarly journals The Dynamics of Oxidized LDL during Atherogenesis

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Hiroyuki Itabe ◽  
Takashi Obama ◽  
Rina Kato
Keyword(s):  
Time Course ◽  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Oxidized Low Density Lipoprotein ◽  
Atherosclerotic Lesions ◽  
Long Duration ◽  
Course Changes ◽  
Classical Hypothesis

Accumulating evidence indicates that oxidized low-density lipoprotein (OxLDL) is a useful marker for cardiovascular disease. The uptake of OxLDL by scavenger receptors leads to the accumulation of cholesterol within the foam cells of atherosclerotic lesions. OxLDL has many stimulatory effects on vascular cells, and the presence of OxLDL in circulating blood has been established. According to the classical hypothesis, OxLDL accumulates in the atherosclerotic lesions over a long duration, leading to advanced lesions. However, recent studies on time-course changes of OxLDLin vivoraised a possibility that OxLDL can be transferred between the lesions and the circulation. In this paper, thein vivodynamics of OxLDL are discussed.

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