scholarly journals A dynamic model of calcific nodule destabilization in response to monocyte- and oxidized lipid-induced matrix metalloproteinases

2012 ◽  
Vol 302 (4) ◽  
pp. C658-C665 ◽  
Author(s):  
Rongsong Li ◽  
David Mittelstein ◽  
Juhyun Lee ◽  
Karen Fang ◽  
Rohit Majumdar ◽  
...  
Keyword(s):  
Atherosclerotic Plaque ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Fibrous Cap ◽  
Mmp Inhibitor ◽  
Pulsatile Shear Stress ◽  
Vitro Model ◽  
Calcifying Vascular Cells ◽  
Force Profiles

Vulnerable plaque remains clinically undetectable, and there is no accepted in vitro model. We characterize the calcific nodules produced by calcifying vascular cells (CVC) in ApoE-null mice, demonstrating increased destabilization of cultured nodules in the presence of oxidized low-density lipoprotein (oxLDL) and monocytes under pulsatile shear stress. CVC implanted in the subcutaneous space of hyperlipidemic mice produced nodules revealing features of calcific atherosclerotic plaque including a fibrous cap, cholesterol clefts, thin shoulder, lipids, and calcium mineral deposits. CVC nodules seeded in the pulsatile flow channel ( τavg = 23 dyn/cm2, ∂ τ/∂ t = 71 dyn·cm−2·s−1) underwent deformation and destabilization. Computational fluid dynamics revealed distinct shear force profiles on the nodules. Presence of oxLDL or monocytic THP-1 cells significantly increased the numbers of nodules destabilized from the substrate. Both oxLDL and THP-1 increased matrix metalloproteinase (MMP) activity in CVC. The MMP inhibitor GM6001 significantly reversed oxLDL- and THP-1-induced nodule destabilization, whereas overexpression of MMP-9 increased destabilization. These findings demonstrate that CVC-derived nodules resembled calcific atherosclerotic plaque and were destabilized in the presence of active lipids and monocytes via induction of MMPs.

An in vitro model to study lipolysis of rat hepatic very low density lipoprotein using cardiac lipoprotein lipase

1984 ◽  
Vol 62 (11) ◽  
pp. 1076-1080 ◽  
Author(s):  
Louise Brissette ◽  
Simon-Pierre Noël
Keyword(s):  
Lipase Activity ◽  
In Vitro Model ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Triacylglycerol Hydrolysis ◽  
Vitro Model ◽  
Fasted Rats

The purpose of this work was to design an in vitro model for studying the lipolysis of very low density lipoprotein (VLDL) under conditions that approximate those likely to exist in the rat circulation. We first measured the total lipase activity available in the circulation of normal fasted rats. Knowing the VLDL-triacylglycerol concentration and the circulating time of VLDL in rat serum, we calculated that incubating 80 mU of lipoprotein lipase activity per milligram of VLDL triacylglycerols at 37 °C, for 50 min, approximated the in vivo conditions of lipolysis in normal fasted rats. Under these conditions, different concentrations of albumin were tested. The degree of lipolysis gradually increased from 25 ± 10% without albumin to 75 ± 5% (mean ± SD, n = 3) with 4% albumin. No further increase occurred above 4% albumin. The rate of triacylglycerol hydrolysis was faster with VLDL having a high triacylglycerol/protein ratio. However after 50–60 min of incubation, the extent of hydrolysis tended to become similar for all VLDL (75–90%). This suggests that the rate of VLDL hydrolysis differs from one particle to another (depending on the size), but the extent of hydrolysis ends up being approximately the same. Furthermore, addition of high density lipoprotein to the incubation medium did not affect the rate nor the extent of triacylglycerol hydrolysis. We conclude that a large proportion of VLDL triacylglycerols can be hydrolyzed in the normal fasted rat if there is no limitation in the capacity of fatty acid removal from the lipolysis site. The physiological significance of these results obtained in vitro is discussed.

scholarly journals Novel Plaque Enriched Long Noncoding RNA in Atherosclerotic Macrophage Regulation (PELATON)

2020 ◽  
Vol 40 (3) ◽  
pp. 697-713 ◽  
Author(s):  
John Hung ◽  
Jessica P. Scanlon ◽  
Amira D. Mahmoud ◽  
Julie Rodor ◽  
Margaret Ballantyne ◽  
...  
Keyword(s):  
Atherosclerotic Plaque ◽  
Noncoding Rna ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Cell Types ◽  
Lipid Uptake ◽  
Unstable Plaque ◽  
Inflammatory Bowel ◽  
Unstable Atherosclerotic Plaque

Objective: Long noncoding RNAs (lncRNAs) are an emergent class of molecules with diverse functional roles, widely expressed in human physiology and disease. Although some lncRNAs have been identified in cardiovascular disease, their potential as novel targets in the prevention of atherosclerosis is unknown. We set out to discover important lncRNAs in unstable plaque and gain insight into their functional relevance. Approach and Results: Analysis of RNA sequencing previously performed on stable and unstable atherosclerotic plaque identified a panel of 47 differentially regulated lncRNAs. We focused on LINC01272, a lncRNA upregulated in unstable plaque previously detected in inflammatory bowel disease, which we termed PELATON (plaque enriched lncRNA in atherosclerotic and inflammatory bowel macrophage regulation). Here, we demonstrate that PELATON is highly monocyte- and macrophage-specific across vascular cell types, and almost entirely nuclear by cellular fractionation (90%–98%). In situ hybridization confirmed enrichment of PELATON in areas of plaque inflammation, colocalizing with macrophages around the shoulders and necrotic core of human plaque sections. Consistent with its nuclear localization, and despite containing a predicted open reading frame, PELATON did not demonstrate any protein-coding potential in vitro. Functionally, knockdown of PELATON significantly reduced phagocytosis, lipid uptake and reactive oxygen species production in high-content analysis, with a significant reduction in phagocytosis independently validated. Furthermore, CD36, a key mediator of phagocytic oxLDL (oxidized low-density lipoprotein) uptake was significantly reduced with PELATON knockdown. Conclusions: PELATON is a nuclear expressed, monocyte- and macrophage-specific lncRNA, upregulated in unstable atherosclerotic plaque. Knockdown of PELATON affects cellular functions associated with plaque progression.

Low-Density Lipoprotein Apheresis and Regression of Atherosclerotic Plaque In Vitro

1986 ◽  
Vol 10 (6) ◽  
pp. 466-469 ◽  
Author(s):  
Alexander N. Orekhov ◽  
Khairulla A. Khashimov ◽  
Dmitry N. Mukhin ◽  
Vladimir V. Tertov ◽  
Irina Yu. Adamova ◽  
...  
Keyword(s):  
Atherosclerotic Plaque ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Apheresis

scholarly journals Myofibroblast Forms Atherosclerotic Plaques

2020 ◽  
Author(s):  
Xinggang Wang ◽  
Junbo Ge
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Foam Cells ◽  
Collagen Fibers ◽  
Atherosclerotic Plaques ◽  
Fibrous Cap ◽  
Future Treatments ◽  
First Time ◽  
Lipids Accumulation

AbstractFor decades, smooth muscle cells (SMCs) and macrophages are considered as the main contributors to atherosclerotic plaques. However, we found that in the human coronary atherosclerotic plaques, SMCs were few, while lots of myofibroblasts infiltrated in the intima near the lumen (fibrous cap) and their distribution was highly positive related to intimal thickness. In addition to lots of foam cells formation, collagen fibers were forming in the thickening intima near the lumen (fibrous cap), and denaturing or calcifying gradually far from the lumen, which evolved into various complex plaques. In vitro, myofibroblasts could actively take lots of low-density lipoprotein (LDL) to enhance proliferation. Lots of collagen fibers, foam cells and extracellular lipids accumulation emerged in myofibroblasts cultured with 5% FBS high glucose DMEM without adding modified LDL. It is consistent with the characteristics of human coronary atherosclerotic plaques. It is the first time that lipid rich plaques with lots of foam cells, extracellular lipids and collagen fibers formed in vitro. It demonstrated that myofibroblast should be the direct and main source of collagen fibers, foam cells and extracellular lipids. This suggests that atherosclerosis is not as complicated as previously considered, and it might be mainly a process of myofibroblast remodeling to vascular injury caused by various risk factors. This study made the pathogenesis of atherosclerosis clearer. It would provide a target cell for future treatments of atherosclerotic diseases. In vitro atherosclerotic plaques model formed by human myofibroblasts would be an efficient and convenient way to study atherosclerosis.

Therapeutic Application of Diacylglycerol Oil for Obesity: Serotonin Hypothesis

2012 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
Hidekatsu Yanai ◽  
Hiroshi Yoshida ◽  
Yuji Hirowatari ◽  
Norio Tada
Keyword(s):  
Energy Expenditure ◽  
Molecular Mechanisms ◽  
Uncoupling Protein ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Serotonin Release ◽  
Intestinal Cell ◽  
Therapeutic Application ◽  
Postprandial Triglyceride

Characteristics for the serum lipid abnormalities in the obesity/metabolic syndrome are elevated fasting, postprandial triglyceride (TG), and decreased high-density lipoprotein-cholesterol (HDL-C). Diacylglycerol (DAG) oil ingestion has been reported to ameliorate postprandial hyperlipidemia and prevent obesity by increasing energy expenditure, due to the intestinal physiochemical dynamics that differ from triacylglycerol (TAG). Our study demonstrated that DAG suppresses postprandial increase in TG-rich lipoprotein, very low-density lipoprotein (VLDL), and insulin, as compared with TAG in young, healthy individuals. Interestingly, our study also presented that DAG significantly increases plasma serotonin, which is mostly present in the intestine, and mediates thermogenesis, proposing a possible mechanism for a postprandial increase in energy expenditure by DAG. Our other study demonstrated that DAG suppresses postprandial increase in TG, VLDL-C, and remnant-like particle-cholesterol, in comparison with TAG in an apolipoprotein C-II deficient subject, suggesting that DAG suppresses postprandial TG-rich lipoprotein independently of lipoprotein lipase. Further, to understand the molecular mechanisms for DAG-mediated increase in serotonin and energy expenditure, we studied the effects of 1-monoacylglycerol and 2-monoacylglycerol, distinct digestive products of DAG and TAG, respectively, on serotonin release from the Caco-2 cells, the human intestinal cell line. We also studied effects of 1- and 2-monoacylglycerol, and serotonin on the expression of mRNA associated with β-oxidation, fatty acids metabolism, and thermogenesis, in the Caco-2 cells. 1-monoacylglycerol significantly increased serotonin release from the Caco-2 cells, compared with 2-monoacylglycerol by approximately 40%. The expression of mRNA of acyl-CoA oxidase (ACO), fatty acid translocase (FAT), and uncoupling protein-2 (UCP-2), was significantly higher in 1-MOG-treated Caco-2 cells, than 2-MOG-treated cells. The expression of mRNA of ACO, medium-chain acyl-CoA dehydrogenase, FAT, and UCP-2, was significantly elevated in serotonin-treated Caco-2 cells, compared to cells incubated without serotonin. In conclusion, our clinical and in vitro studies suggested a possible therapeutic application of DAG for obesity, and obesity-related metabolic disorders.Key words: Diacylglycerol, intestine, obesity, serotonin, thermogenesis

scholarly journals Comparative Evaluation on Impacts of Fibronectin, Heparin–Chitosan, and Albumin Coating of Bacterial Nanocellulose Small-Diameter Vascular Grafts on Endothelialization In Vitro

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1952
Author(s):  
Max Wacker ◽  
Jan Riedel ◽  
Heike Walles ◽  
Maximilian Scherner ◽  
George Awad ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Density Lipoprotein ◽  
Human Albumin ◽  
Water Soluble ◽  
Bacterial Nanocellulose ◽  
Functionally Impaired ◽  
Small Diameter Vascular Grafts

In this study, we contrast the impacts of surface coating bacterial nanocellulose small-diameter vascular grafts (BNC-SDVGs) with human albumin, fibronectin, or heparin–chitosan upon endothelialization with human saphenous vein endothelial cells (VEC) or endothelial progenitor cells (EPC) in vitro. In one scenario, coated grafts were cut into 2D circular patches for static colonization of a defined inner surface area; in another scenario, they were mounted on a customized bioreactor and subsequently perfused for cell seeding. We evaluated the colonization by emerging metabolic activity and the preservation of endothelial functionality by water soluble tetrazolium salts (WST-1), acetylated low-density lipoprotein (AcLDL) uptake assays, and immune fluorescence staining. Uncoated BNC scaffolds served as controls. The fibronectin coating significantly promoted adhesion and growth of VECs and EPCs, while albumin only promoted adhesion of VECs, but here, the cells were functionally impaired as indicated by missing AcLDL uptake. The heparin–chitosan coating led to significantly improved adhesion of EPCs, but not VECs. In summary, both fibronectin and heparin–chitosan coatings could beneficially impact the endothelialization of BNC-SDVGs and might therefore represent promising approaches to help improve the longevity and reduce the thrombogenicity of BNC-SDVGs in the future.

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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