scholarly journals Role of R-spondin 2 in arterial lymphangiogenesis and atherosclerosis

2020 ◽  
Author(s):  
Bhupesh Singla ◽  
Hui-Ping Lin ◽  
Alex Chen ◽  
WonMo Ahn ◽  
Pushpankur Ghoshal ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cholesterol Efflux ◽  
Matrix Protein ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lymphatic Drainage ◽  
Control Treatment

Abstract Aims Impaired lymphatic drainage of the arterial wall results in intimal lipid accumulation and atherosclerosis. However, the mechanisms regulating lymphangiogenesis in atherosclerotic arteries are not well understood. Our studies identified elevated levels of matrix protein R-spondin 2 (RSPO2) in atherosclerotic arteries. In this study, we investigated the role of RSPO2 in lymphangiogenesis, arterial cholesterol efflux into lesion-draining lymph nodes (LNs) and development of atherosclerosis. Methods and results The effect of RSPO2 on lymphangiogenesis was investigated using human lymphatic endothelial cells (LEC) in vitro and implanted Matrigel plugs in vivo. Cellular and molecular approaches, pharmacological agents, and siRNA silencing of RSPO2 receptor LGR4 were used to investigate RSPO2-mediated signalling in LEC. In vivo low-density lipoprotein (LDL) tracking and perivascular blockade of RSPO2–LGR4 signalling using LGR4-extracellular domain (ECD) pluronic gel in hypercholesterolemic mice were utilized to investigate the role of RSPO2 in arterial reverse cholesterol transport and atherosclerosis. Immunoblotting and imaging experiments demonstrated increased RSPO2 expression in human and mouse atherosclerotic arteries compared to non-atherosclerotic controls. RSPO2 treatment inhibited lymphangiogenesis both in vitro and in vivo. LGR4 silencing and inhibition of RSPO2–LGR4 signalling abrogated RSPO2-induced inhibition of lymphangiogenesis. Mechanistically, we found that RSPO2 suppresses PI3K-AKT-endothelial nitric oxide synthase (eNOS) signalling via LGR4 and inhibits activation of the canonical Wnt-β-catenin pathway. ApoE−/− mice treated with LGR4-ECD developed significantly less atherosclerosis compared with control treatment. Finally, increased arterial lymphatic vessel density and improved lymphatic drainage of fluorescently labelled LDL to deep cervical LNs were observed in LGR4-ECD-treated mice. Conclusion These findings demonstrate that RSPO2 inhibits lymphangiogenesis via LGR4 and downstream impairment of AKT-eNOS-nitric oxide signalling. These results may also inform new therapeutic strategies to promote lymphangiogenesis and improve cholesterol efflux from atherosclerotic arteries.

scholarly journals Role of PCSK9 in Homocysteine-Accelerated Lipid Accumulation in Macrophages and Atherosclerosis in ApoE−/− Mice

2021 ◽  
Vol 8 ◽  
Author(s):  
Ping Jin ◽  
Dengfeng Gao ◽  
Guangzhi Cong ◽  
Ru Yan ◽  
Shaobin Jia
Keyword(s):  
Lipid Accumulation ◽  
Cholesterol Efflux ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipid Lowering ◽  
Lesion Area ◽  
Atherosclerotic Lesions

Background: Homocysteine (Hcy) has been established as an independent risk factor for atherosclerosis, and the involvement of hyperhomocysteinemia (HHcy) in atherosclerotic lesions is complex. Proprotein convertase subtilisin kexin 9 (PCSK9) has vital importance in lipid metabolism, and its inhibitors have intense lipid-lowering and anti-atherosclerotic effects. However, the underlying effect of PCSK9 on HHcy-accelerated dyslipidemia of macrophages is still uncertain. The purpose of this study was to investigate the potential role of PCSK9 in Hcy-induced lipid accumulation and atherosclerotic lesions.Methods:In vitro, gene and protein expressions were assessed by real-time quantitative PCR and western blot in THP-1 macrophages with Hcy incubation. Lipid accumulation and cholesterol efflux were evaluated with Hcy treatment. SBC-115076 was used to examine the role of PCSK9 in ATP-binding cassette transporter A1 and G1 (ABCA1 and ABCG1)-dependent cholesterol efflux. In vivo, lesion area, lipid deposition and collagen contents were determined in aortas of ApoE−/− mice under a methionine diet. SBC-115076 was subcutaneously injected to explore the potential effects of PCSK9 inhibition on alleviating the severity of HHcy-related atherosclerotic lesions.Results: In THP-1 macrophages, Hcy dose- and time-dependently promoted PCSK9 gene and protein levels without regulating the translation of Low-density lipoprotein receptor (LDLR). SBC-115076 used to inhibit PCSK9 largely alleviated lipid accumulation and reversed the cholesterol efflux to apolipoprotein-I(apoA-I) and high-density lipoprotein (HDL) mediated by ABCA1 and ABCG1. In ApoE−/− mice, methionine diet induced HHcy caused larger lesion area and more lipid accumulation in aortic roots. SBC-115076 reduced atherosclerotic severity by reducing the lesion area and lipid accumulation and increasing expressions of ABCA1 and ABCG1 in macrophages from atherosclerotic plaque. In addition, SBC-115076 decreased plasma Hcy level and lipid profiles significantly.Conclusion: PCSK9 promoted lipid accumulation via inhibiting cholesterol efflux mediated by ABCA1 and ABCG1 from macrophages and accelerated atherosclerotic lesions under HHcy treatment. Inhibiting PCSK9 may have anti-atherogenic properties in HHcy-accelerated atherosclerosis.

Abstract 5: Lipid Droplet Associated Hydrolase: A New Player in Cholesterol Mobilization From Foam Cells

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Younghwa Goo ◽  
Pradip Saha ◽  
Larry Chan ◽  
Antoni Paul
Keyword(s):  
Lipid Droplet ◽  
Cholesterol Efflux ◽  
Bone Marrow Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Foam Cells ◽  
Peritoneal Macrophages ◽  
Cholesterol Homeostasis

Lipid laden macrophages/foam cells are a hallmark of atherosclerotic lesions from early to late stages of development. Macrophages take-up modified low-density lipoprotein (mLDL) particles and store surplus mLDL-derived cholesterol as cholesterol ester (CE) in cytoplasmic lipid droplets (LDs). Accelerating CE hydrolysis from the LDs is a plausible strategy to promote reverse cholesterol transport from the atheroma. However, the identity of the CE hydrolases that function on LDs remains unknown. Previously we identified lipid droplet-associated hydrolase (LDAH) in LDs purified from macrophages and reported that in vitro LDAH regulates CE levels by increasing CE hydrolysis. To determine the relevance of LDAH in atherogenesis, we have generated LDAH knockout (LDAH-/-) mice. Mouse peritoneal macrophages (MPM) isolated from LDAH-/- mice had increased cytoplasmic LDs, increased net CE content, and decreased cholesterol efflux. In atherosclerosis studies, both male and female LDAH-/- mice crossed with apolipoprotein E knockout (apoE-/-) mice fed a Western diet developed larger lesions. Lesions of LDAH-/-/ apoE-/- mice were characterized by increased areas of macrophages containing enlarged cytoplasms with large LDs. Supporting a direct atheroprotective role of LDAH in macrophages, lesions of apoE-/- mice that received bone marrows from LDAH-/-/apoE-/- mice progressed faster than those that received bone marrow cells from LDAH+/+/apoE-/- mice. In qPCR analyses of genes involved in cholesterol homeostasis in macrophages, we found that ABC binding cassette transporters ABCA1 and ABCG1, which mediate cholesterol efflux through the plasma membrane, were consistently decreased in LDAH-/- MPM. Further in vivo gene expression studies on macrophages selectively obtained from lesions using laser capture microdissection are underway. In conclusion, our study suggests that LDAH promotes LD CE hydrolysis and cholesterol efflux from foam cells within the atheroma, and uncovers a potential target to promote reverse cholesterol from arteries as a means of ameliorating atherosclerosis development.

scholarly journals Wide Biological Role of Hydroxytyrosol: Possible Therapeutic and Preventive Properties in Cardiovascular Diseases

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1932
Author(s):  
Chiara D’Angelo ◽  
Sara Franceschelli ◽  
José Luis Quiles ◽  
Lorenza Speranza
Keyword(s):  
Cardiovascular Health ◽  
Biological Effects ◽  
Low Density Lipoprotein ◽  
Antioxidant Properties ◽  
Density Lipoprotein ◽  
In Vivo Models ◽  
And Oxidative Stress

The growing incidence of cardiovascular disease (CVD) has promoted investigations of natural molecules that could prevent and treat CVD. Among these, hydroxytyrosol, a polyphenolic compound of olive oil, is well known for its antioxidant, anti-inflammatory, and anti-atherogenic effects. Its strong antioxidant properties are due to the scavenging of radicals and the stimulation of synthesis and activity of antioxidant enzymes (SOD, CAT, HO-1, NOS, COX-2, GSH), which also limit the lipid peroxidation of low-density lipoprotein (LDL) cholesterol, a hallmark of atherosclerosis. Lowered inflammation and oxidative stress and an improved lipid profile were also demonstrated in healthy subjects as well as in metabolic syndrome patients after hydroxytyrosol (HT) supplementation. These results might open a new therapeutic scenario through personalized supplementation of HT in CVDs. This review is the first attempt to collect together scientific literature on HT in both in vitro and in vivo models, as well as in human clinical studies, describing its potential biological effects for cardiovascular health.

scholarly journals Arterial heparin deposition: role of diffusion, convection, and extravascular space

1998 ◽  
Vol 275 (6) ◽  
pp. H2236-H2242 ◽  
Author(s):  
Mark A. Lovich ◽  
Mike Philbrook ◽  
Sean Sawyer ◽  
Ed Weselcouch ◽  
Elazer R. Edelman
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Perivascular Space ◽  
Low Density ◽  
Pressure Gradients ◽  
Extravascular Space ◽  
Diffusion Convection

Transvascular transport has been studied with atherogenic, tracer, and inert compounds such as low-density lipoprotein, horseradish peroxidase, and albumin, respectively. Few studies used vasoactive compounds, and virtually all studies examined entry from the lumen and not from the perivascular space. We compared several mechanisms that govern arterial heparin deposition after administration to the perivascular and endovascular aspects of the calf carotid artery in vitro and the rabbit iliac artery in vivo. In the absence of transmural hydrostatic pressure gradients, heparin deposition following endovascular administration was unaffected by deendothelialization and was indistinguishable from perivascular delivery. Deposition in the former was enhanced by the addition of a pressure gradient and to a greater extent in denuded arteries, indicating that convection influences transport but is dampened by the endothelium. Neither the endothelium nor the adventitia pose significant resistances to heparin. Deposition in vivo was greater following endovascular hydrogel release than perivascular application from similar devices to native or denuded arteries. The loss of drug to extra-arterial microvessels exceeded the loss of drug to the lumen flow. These findings are essential for describing vascular pharmacokinetics and for implementing local pharmacotherapies.

Role of receptor-mediated endocytosis in the antiangiogenic effects of human T lymphoblastic cell-derived microparticles

2012 ◽  
Vol 302 (8) ◽  
pp. R941-R949 ◽  
Author(s):  
Chun Yang ◽  
Wei Xiong ◽  
Qian Qiu ◽  
Zuo Shao ◽  
David Hamel ◽  
...  
Keyword(s):  
Cell Growth ◽  
Protein Expression ◽  
Therapeutic Potential ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Vascular Density ◽  
Receptor Mediated Endocytosis

Microparticles possess therapeutic potential regarding angiogenesis. We have demonstrated the contribution of apoptotic human CEM T lymphocyte-derived microparticles (LMPs) as inhibitors of angiogenic responses in animal models of inflammation and tumor growth. In the present study, we characterized the antivascular endothelial growth factor (VEGF) effects of LMPs on pathological angiogenesis in an animal model of oxygen-induced retinopathy and explored the role of receptor-mediated endocytosis in the effects of LMPs on human retinal endothelial cells (HRECs). LMPs dramatically inhibited cell growth of HRECs, suppressed VEGF-induced cell migration in vitro experiments, and attenuated VEGF-induced retinal vascular leakage in vivo. Intravitreal injections of fluorescently labeled LMPs revealed accumulation of LMPs in retinal tissue, with more than 60% reductions of the vascular density in retinas of rats with oxygen-induced neovascularization. LMP uptake experiments demonstrated that the interaction between LMPs and HRECs is dependent on temperature. In addition, endocytosis is partially dependent on extracellular calcium. RNAi-mediated knockdown of low-density lipoprotein receptor (LDLR) reduced the uptake of LMPs and attenuated the inhibitory effects of LMPs on VEGF-A protein expression and HRECs cell growth. Intravitreal injection of lentivirus-mediated RNA interference reduced LDLR protein expression in retina by 53% and significantly blocked the antiangiogenic effects of LMPs on pathological vascularization. In summary, the potent antiangiogenic LMPs lead to a significant reduction of pathological retinal angiogenesis through modulation of VEGF signaling, whereas LDLR-mediated endocytosis plays a partial, but pivotal, role in the uptake of LMPs in HRECs.

scholarly journals Role of TNF-α in vascular dysfunction

2009 ◽  
Vol 116 (3) ◽  
pp. 219-230 ◽  
Author(s):  
Hanrui Zhang ◽  
Yoonjung Park ◽  
Junxi Wu ◽  
Xiu ping Chen ◽  
Sewon Lee ◽  
...  
Keyword(s):  
Vascular Function ◽  
Vascular Dysfunction ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Nuclear Factor Κb ◽  
Tnf Α ◽  
Density Lipoprotein Receptor

Healthy vascular function is primarily regulated by several factors including EDRF (endothelium-dependent relaxing factor), EDCF (endothelium-dependent contracting factor) and EDHF (endothelium-dependent hyperpolarizing factor). Vascular dysfunction or injury induced by aging, smoking, inflammation, trauma, hyperlipidaemia and hyperglycaemia are among a myriad of risk factors that may contribute to the pathogenesis of many cardiovascular diseases, such as hypertension, diabetes and atherosclerosis. However, the exact mechanisms underlying the impaired vascular activity remain unresolved and there is no current scientific consensus. Accumulating evidence suggests that the inflammatory cytokine TNF (tumour necrosis factor)-α plays a pivotal role in the disruption of macrovascular and microvascular circulation both in vivo and in vitro. AGEs (advanced glycation end-products)/RAGE (receptor for AGEs), LOX-1 [lectin-like oxidized low-density lipoprotein receptor-1) and NF-κB (nuclear factor κB) signalling play key roles in TNF-α expression through an increase in circulating and/or local vascular TNF-α production. The increase in TNF-α expression induces the production of ROS (reactive oxygen species), resulting in endothelial dysfunction in many pathophysiological conditions. Lipid metabolism, dietary supplements and physical activity affect TNF-α expression. The interaction between TNF-α and stem cells is also important in terms of vascular repair or regeneration. Careful scrutiny of these factors may help elucidate the mechanisms that induce vascular dysfunction. The focus of the present review is to summarize recent evidence showing the role of TNF-α in vascular dysfunction in cardiovascular disease. We believe these findings may prompt new directions for targeting inflammation in future therapies.

scholarly journals Phaseolin Attenuates Lipopolysaccharide-Induced Inflammation in RAW 264.7 Cells and Zebrafish

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 420
Author(s):  
Su-Jung Hwang ◽  
Ye-Seul Song ◽  
Hyo-Jong Lee
Keyword(s):  
Nitric Oxide ◽  
Nuclear Translocation ◽  
Raw 264.7 Cells ◽  
Network Pharmacology ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Bioactive Constituents

Kushen (Radix Sophorae flavescentis) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of S. flavescentis. However, the role of phaseolin (one of the primary components of S. flavescentis) in the direct regulation of inflammation and inflammatory processes is not well known. In this study, the beneficial role of phaseolin against inflammation was explored in lipopolysaccharide (LPS)-induced inflammation models of RAW 264.7 macrophages and zebrafish larvae. Phaseolin inhibited LPS-mediated production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), without affecting cell viability. In addition, phaseolin suppressed pro-inflammatory mediators such as cyclooxygenase 2 (COX-2), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in a dose-dependent manner. Furthermore, phaseolin reduced matrix metalloproteinase (MMP) activity as well as macrophage adhesion in vitro and the recruitment of leukocytes in vivo by downregulating Ninjurin 1 (Ninj1), an adhesion molecule. Finally, phaseolin inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB). In view of the above, our results suggest that phaseolin could be a potential therapeutic candidate for the management of inflammation.

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.

scholarly journals Novel Insights on the Role of Nitric Oxide in the Ovary: A Review of the Literature

2021 ◽  
Vol 18 (3) ◽  
pp. 980
Author(s):  
Maria Cristina Budani ◽  
Gian Mario Tiboni
Keyword(s):  
Nitric Oxide ◽  
In Vivo Studies ◽  
Published Data ◽  
Vitro Fertilization ◽  
Peripheral Neurons ◽  
Relevant Role ◽  
Oocyte Meiotic Maturation

Nitric oxide (NO) is formed during the oxidation of L-arginine to L-citrulline by the action of multiple isoenzymes of NO synthase (NOS): neuronal NOS (nNOS), endotelial NOS (eNOS), and inducible NOS (iNOS). NO plays a relevant role in the vascular endothelium, in central and peripheral neurons, and in immunity and inflammatory systems. In addition, several authors showed a consistent contribution of NO to different aspects of the reproductive physiology. The aim of the present review is to analyse the published data on the role of NO within the ovary. It has been demonstrated that the multiple isoenzymes of NOS are expressed and localized in the ovary of different species. More to the point, a consistent role was ascribed to NO in the processes of steroidogenesis, folliculogenesis, and oocyte meiotic maturation in in vitro and in vivo studies using animal models. Unfortunately, there are few nitric oxide data for humans; there are preliminary data on the implication of nitric oxide for oocyte/embryo quality and in-vitro fertilization/embryo transfer (IVF/ET) parameters. NO plays a remarkable role in the ovary, but more investigation is needed, in particular in the context of human ovarian physiology.

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