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PI3KCIIα-Dependent Autophagy Program Protects From Endothelial Dysfunction and Atherosclerosis in Response to Low Shear Stress in Mice. Arterioscler Thromb Vasc Biol 2024; 44:620-634. [PMID: 38152888 DOI: 10.1161/atvbaha.123.319978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 12/12/2023] [Indexed: 12/29/2023]
Abstract
BACKGROUND The ability to respond to mechanical forces is a basic requirement for maintaining endothelial cell (ECs) homeostasis, which is continuously subjected to low shear stress (LSS) and high shear stress (HSS). In arteries, LSS and HSS have a differential impact on EC autophagy processes. However, it is still unclear whether LSS and HSS differently tune unique autophagic machinery or trigger specific autophagic responses in ECs. METHODS Using fluid flow system to generate forces on EC and multiscale imaging analyses on ApoE-/- mice whole arteries, we studied the cellular and molecular mechanism involved in autophagic response to LSS or HSS on the endothelium. RESULTS We found that LSS and HSS trigger autophagy activation by mobilizing specific autophagic signaling modules. Indeed, LSS-induced autophagy in endothelium was independent of the class III PI3K (phosphoinositide 3-kinase) VPS34 (vacuolar sorting protein 34) but controlled by the α isoform of class II PI3K (phosphoinositide 3-kinase class II α [PI3KCIIα]). Accordingly, reduced PI3KCIIα expression in ApoE-/- mice (ApoE-/-PI3KCIIα+/-) led to EC dysfunctions associated with increased plaque deposition in the LSS regions. Mechanistically, we revealed that PI3KCIIα inhibits mTORC1 (mammalian target of rapamycin complex 1) activation and that rapamycin treatment in ApoE-/-PI3KCIIα+/- mice specifically rescue autophagy in arterial LSS regions. Finally, we demonstrated that absence of PI3KCIIα led to decreased endothelial primary cilium biogenesis in response to LSS and that ablation of primary cilium mimics PI3KCIIα-decreased expression in EC dysfunction, suggesting that this organelle could be the mechanosensor linking PI3KCIIα and EC homeostasis. CONCLUSIONS Our data reveal that mechanical forces variability within the arterial system determines EC autophagic response and supports a central role of PI3KCIIα/mTORC1 axis to prevent EC dysfunction in LSS regions.
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Leucine-Rich Alpha-2 Glycoprotein 1 Accumulates in Complicated Atherosclerosis and Promotes Calcification. Int J Mol Sci 2023; 24:16537. [PMID: 38003727 PMCID: PMC10671851 DOI: 10.3390/ijms242216537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
Atherosclerosis is the primary cause of cardiovascular disease. The development of plaque complications, such as calcification and neo-angiogenesis, strongly impacts plaque stability and is a good predictor of mortality in patients with atherosclerosis. Despite well-known risk factors of plaque complications, such as diabetes mellitus and chronic kidney disease, the mechanisms involved are not fully understood. We and others have identified that the concentration of circulating leucine-rich α-2 glycoprotein 1 (LRG1) was increased in diabetic and chronic kidney disease patients. Using apolipoprotein E knockout mice (ApoE-/-) (fed with Western diet) that developed advanced atherosclerosis and using human carotid endarterectomy, we showed that LRG1 accumulated into an atherosclerotic plaque, preferentially in calcified areas. We then investigated the possible origin of LRG1 and its functions on vascular cells and found that LRG1 expression was specifically enhanced in endothelial cells via inflammatory mediators and not in vascular smooth muscle cells (VSMC). Moreover, we identified that LRG1 was able to induce calcification and SMAD1/5-signaling pathways in VSMC. In conclusion, our results identified for the first time that LRG1 is a direct contributor to vascular calcification and suggest a role of this molecule in the development of plaque complications in patients with atherosclerosis.
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Smooth muscle cells-derived CXCL10 prevents endothelial healing through PI3Kγ-dependent T cells response. Cardiovasc Res 2020; 116:438-449. [PMID: 31106375 DOI: 10.1093/cvr/cvz122] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 02/25/2019] [Accepted: 05/15/2019] [Indexed: 12/14/2022] Open
Abstract
AIMS Defects in efficient endothelial healing have been associated with complication of atherosclerosis such as post-angioplasty neoatherosclerosis and plaque erosion leading to thrombus formation. However, current preventive strategies do not consider re-endothelialization in their design. Here, we investigate mechanisms linking immune processes and defect in re-endothelialization. We especially evaluate if targeting phosphoinositide 3-kinase γ immune processes could restore endothelial healing and identify immune mediators responsible for these defects. METHODS AND RESULTS Using in vivo model of endovascular injury, we showed that both ubiquitous genetic inactivation of PI3Kγ and hematopoietic cell-specific PI3Kγ deletion improved re-endothelialization and that CD4+ T-cell population drives this effect. Accordingly, absence of PI3Kγ activity correlates with a decrease in local IFNγ secretion and its downstream interferon-inducible chemokine CXCL10. CXCL10 neutralization promoted re-endothelialization in vivo as the same level than those observed in absence of PI3Kγ suggesting a role of CXCL10 in re-endothelialization defect. Using a new established ex vivo model of carotid re-endothelialization, we showed that blocking CXCL10 restore the IFNγ-induced inhibition of endothelial healing and identify smooth muscle cells as the source of CXCL10 secretion in response to Th1 cytokine. CONCLUSION Altogether, these findings expose an unforeseen cellular cross-talk within the arterial wall whereby a PI3Kγ-dependent T-cell response leads to CXCL10 production by smooth muscle cells which in turn inhibits endothelial healing. Therefore, both PI3Kγ and the IFNγ/CXCL10 axis provide novel strategies to promote endothelial healing.
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A non-catalytic function of PI3Kγ drives smooth muscle cell proliferation after arterial damage. J Cell Sci 2020; 133:jcs.245969. [PMID: 32482794 DOI: 10.1242/jcs.245969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 05/14/2020] [Indexed: 01/09/2023] Open
Abstract
Arterial remodeling in hypertension and intimal hyperplasia involves inflammation and disrupted flow, both of which contribute to smooth muscle cell dedifferentiation and proliferation. In this context, our previous results identified phosphoinositide 3-kinase γ (PI3Kγ) as an essential factor in inflammatory processes of the arterial wall. Here, we identify for the first time a kinase-independent role of nonhematopoietic PI3Kγ in the vascular wall during intimal hyperplasia using PI3Kγ-deleted mice and mice expressing a kinase-dead version of the enzyme. Moreover, we found that the absence of PI3Kγ in vascular smooth muscle cells (VSMCs) leads to modulation of cell proliferation, associated with an increase in intracellular cAMP levels. Real-time analysis of cAMP dynamics revealed that PI3Kγ modulates the degradation of cAMP in primary VSMCs independently of its kinase activity through regulation of the enzyme phosphodiesterase 4. Importantly, the use of an N-terminal competing peptide of PI3Kγ blocked primary VSMC proliferation. These data provide evidence for a kinase-independent role of PI3Kγ in arterial remodeling and reveal novel strategies targeting the docking function of PI3Kγ for the treatment of cardiovascular diseases.
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PI3Kg a novel therapeutic target to increase reendothelialization in mice through modulation of CXCL10 secretion. Atherosclerosis 2017. [DOI: 10.1016/j.atherosclerosis.2017.06.429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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PI3Kβ Plays a Key Role in Apolipoprotein A-I-Induced Endothelial Cell Proliferation Through Activation of the Ecto-F1-ATPase/P2Y1 Receptors. Cell Physiol Biochem 2017; 42:579-593. [PMID: 28578353 DOI: 10.1159/000477607] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 04/05/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS High-density lipoproteins (HDL) exert multiple cardioprotective functions on the arterial wall, including the promotion of endothelial cell survival and proliferation. Among mechanism contributing to endothelial protection, it has been reported that apolipoprotein A-I (apoA-I), the major protein in HDL, binds and activates the endothelial ecto-F1-ATPase receptor. This generates extracellular ADP, which in turn promotes endothelial cell survival. In this study we aimed to further investigate the signaling pathway involved downstream of apoA-I-induced ecto-F1-ATPase activation. METHODS In human umbilical vein endothelial cells (HUVECs), pharmacological and gene silencing approaches were used to study pathways involved downstream ecto-F1-ATPase activation by apoA-I. RESULTS ApoA-I and HDL both induced Akt phosphorylation. F1-ATPase inhibitors such as inhibitory factor 1 and oligomycin completely blocked apoA-I-induced Akt phosphorylaton and significantly blocked HDL-induced phosphorylation, indicating that this signaling pathway is dependent on ecto-F1-ATPase activation by apoA-I. Further, we were able to specify roles for the P2Y1-ADPreceptor and the PI3Kβ isoform in this pathway since pharmacological inhibition and silencing of these proteins dramatically inhibited apoA-I-induced Akt phosphorylation and cell proliferation. CONCLUSION Altogether, these data highlight a key role of the P2Y1/PI3Kβ axis in endothelial cell proliferation downstream of ecto-F1-ATPase activation by apoA-I. Pharmacological targeting of this pathway could represent a promising approach to enhance vascular endothelial protection.
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Non catalytic function of PI3Kg on smooth muscle cells proliferation: a novel therapeutic strategy to prevent arterial remodeling through cAMP modulation. ARCHIVES OF CARDIOVASCULAR DISEASES SUPPLEMENTS 2017. [DOI: 10.1016/s1878-6480(17)30522-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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PI3Kgamma a novel therapeutic target to increase reendothelialization in mice through modulation of CXCL10 secretion. ARCHIVES OF CARDIOVASCULAR DISEASES SUPPLEMENTS 2017. [DOI: 10.1016/s1878-6480(17)30376-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Poster session 2Morphogenetic mechanisms290MiR-133 regulates retinoic acid pathway during early cardiac chamber specification291Bmp2 regulates atrial differentiation through miR-130 during early heart looping formationDevelopmental genetics294Association of deletion allele of insertion/deletion polymorphism in alpha 2B adrenoceptor gene and hypertension with or without type 2 diabetes mellitus295Association of G1359A polymorphism of the endocannabinoid type 1 receptor (CNR1) with coronary artery disease (CAD) with type 2 diabetes mellitusCell growth, differentiation and stem cells - Vascular298Gamma-secretase inhibitor prevents proliferation and migration of ductus arteriosus smooth muscle cells: a role of Notch signaling in postnatal closure of ductus arteriosus299Mesenchymal stromal-like cells (MLCs) derived from induced pluripotent stem (iPS) cells: a promising therapeutic option to promote neovascularization300Sonic Hedgehog promotes mesenchymal stem cell differentiation to vascular smooth muscle cells in cardiovacsular disease301Proinflammatory cytokine secretion and epigenetic modification in endothelial cells treated LPS-GinfivalisCell death and apoptosis - Vascular304Mitophagy acts as a safeguard mechanism against human vascular smooth muscle cell apoptosis induced by atherogenic lipidsTranscriptional control and RNA species - Vascular307MicroRNA-34a role in vascular calcification308Local delivery of a miR-146a inhibitor utilizing a clinically applicable approach attenuates neointima formation after vascular injury309Long noncoding RNA landscape of hypoxic endothelial cells310Specific circulating microRNAs levels associate with hypertension, hyperglycemia and dysfunctional HDL in acute coronary syndrome patientsCytokines and cellular inflammation - Vascular313Phosphodiesterase5A up-regulation in vascular endothelium under pro-inflammatory conditions: a newly disclosed anti-inflammatory activity for the omega-3polyunsaturated aatty acid docosahexaenoic acid314Cardiovascular risk modifying with extra-low dose anticytokine drugs in rhematoid arthritis315Conversion of human M-CSF macrophages into foam cells reduces their proinflammatory responses to classical M1-polarizing activation316Lymphocytic myocarditis coincides with increased plaque inflammation and plaque hemorrhage in coronary arteries, facilitating myocardial infarction317Serum osteoprotegerin level predictsdeclined numerous of circulating endothelial- derived and mononuclear-derived progenitor cells in patients with metabolic syndromeGrowth factors and neurohormones - Vascular320Effect of gastrin-releasing peptide (GRP) on vascular inflammationSignal transduction - Heart323A new synthetic peptide regulates hypertrophy in vitro through means of the inhibition of nfkb324Inducible fibroblast-specific knockout of p38 alpha map kinase is cardioprotective in a mouse model of isoproterenol-induced cardiac hypertrophy325Regulation of beta-adrenoceptor-evoked inotropic responses by inhibitory G protein, adenylyl cyclase isoforms 5 and 6 and phosphodiesterases326Binding to RGS3 and stimulation of M2 muscarinic acetylcholine receptors modulates the substrate specificity of p190RhoGAP in cardiac myocytes327Cardiac regulation of post-translational modifications, parylation and deacetylation in LMNA dilated cardiomyopathy mouse model328Beta-adrenergic regulation of the b56delta/pp2a holoenzyme in cardiac myocytes through b56delta phosphorylation at serine 573Nitric oxide and reactive oxygen species - Vascular331Oxidative stress-induced miR-200c disrupts the regulatory loop among SIRT1, FOXO1 and eNOS332Antioxidant therapy prevents oxidative stress-induced endothelial dysfunction and Enhances Wound Healing333Morphological and biochemical characterization of red blood cell in coronary artery diseaseCytoskeleton and mechanotransduction - Heart336Novel myosin activator, JSH compounds, increased myocardial contractility without chronotropic effect in ratsExtracellular matrix and fibrosis - Vascular339Ablation of Toll-like receptor 9 causes cardiac rupture after myocardial infarction by attenuating proliferation and differentiation of cardiac fibroblasts340Altered vascular remodeling in the mouse hind limb ischemia model in Factor VII activating protease (FSAP) deficiencyVasculogenesis, angiogenesis and arteriogenesis343Pro-angiogenic effects of proly-hydroxylase inhibitors and their potential for use in a novel strategy of therapeutic angiogenesis for coronary total occlusion344Nrf2 drives angiogenesis in transcription-independent manner: new function of the master regulator of oxidative stress response345Angiogenic gene therapy, despite efficient vascular growth, is not able to improve muscle function in normoxic or chronically ischemic rabbit hindlimbs -role of capillary arterialization and shunting346Effect of PAR-1 inhibition on collateral vessel growth in the murine hind limb model347Quaking is a key regulator of endothelial cell differentiation, neovascularization and angiogenesis348"Emerging angiogenesis" in the chick chorioallantoic membrane (CAM). An in vivo study349Exosomes from cardiomyocyte progenitor cells and mesenchymal stem cells stimulate angiogenesis in vitro and in vivo via EMMPRINEndothelium352Reciprocal regulation of GRK2 and bradykinin receptor stimulation modulate Ca2+ intracellular level in endothelial cells353The roles of bone morphogenetic proteins 9 and 10 in endothelial inflammation and atherosclerosis354The contribution of GPR55 to the L-alpha-lysophosphatidylinositol-induced vasorelaxation in isolated human pulmonary arteries355The endothelial protective ACE inhibitor Zofenoprilat exerts anti-inflammatory activities through H2S production356A new class of glycomimetic drugs to prevent free fatty acid-induced endothelial dysfunction357Endothelial progenitor cells to apoptotic endothelial cell-derived microparticles ration differentiatesas preserved from reduced ejection fractionheart failure358Proosteogenic genes are activated in endothelial cells of patients with thoracic aortic aneurysm359Endothelin ETB receptors mediate relaxing responses to insulin in pericardial resistance arteries from patients with cardiovascular disease (CVD)Smooth muscle and pericytes362CX3CR1 positive myeloid cells regulate vascular smooth muscle tone by inducing calcium oscillations via activation of IP3 receptors363A novel function of PI3Kg on cAMP regulation, role in arterial wall hyperplasia through modulation of smooth muscle cells proliferation364NRP1 and NRP2 play important roles in the development of neointimal hyperplasia in vivo365Azithromycin induces autophagy in aortic smooth muscle cellsCoagulation, thrombosis and platelets368The real time in vivo evaluation of platelet-dependent aldosterone prothrombotic action in mice369Development of a method for in vivo detection of active thrombi in mice370The antiplatelet effects of structural analogs of the taurine chloramine371The influence of heparin anticoagulant drugs on functional state of human platelets372Regulation of platelet aggregation and adenosine diphosphate release by d dimer in acute coronary syndrome (in vitro study)Oxygen sensing, ischaemia and reperfusion375Sirtuin 5 mediates brain injury in a mouse model of cerebral ischemia-reperfusion376Abscisic acid: a new player in cardiomyocyte protection from ischaemia?377Protective effects of ultramicronized palmitoylethanolamide (PEA-um) in myocardial ischaemia and reperfusion injury in vivo378Identification of stem cell-derived cardiomyocytes using cardiac specific markers and additional testing of these cells in simulated ischemia/reperfusion system379Single-dose intravenous metformin treatment could afford significant protection of the injured rat kidney in an experimental model of ischemia-reperfusion380Cardiotoxicity of long acting muscarinic receptor antagonists used for chronic obstructive pulmonary disease381Dependence antioxidant potential on the concentration of amino acids382The impact of ischemia-reperfusion on physiological parameters,apoptosis and ultrastructure of rabbit myocardium with experimental aterosclerosisMitochondria and energetics385MicroRNA-1 dependent regulation of mitochondrial calcium uniporter (MCU) in normal and hypertrophied hearts386Mitochondrial homeostasis and cardioprotection: common targets for desmin and aB-crystallin387Overexpression of mitofusin-2 (Mfn2) and associated mitochondrial dysfunction in the diabetic heart388NO-dependent prevention of permeability transition pore (MPTP) opening by H2S and its regulation of Ca2+ accumulation in rat heart mitochondria389G protein coupled receptor kinase 2 (GRK2) is fundamental in recovering mitochondrial morphology and function after exposure to ionizing radiation (IR)Gender issues392Sex differences in pulmonary vascular control; focus on the nitric oxide pathwayAging395Heart failure with preserved ejection fraction develops when feeding western diet to senescence-accelerated mice396Cardiovascular markers as predictors of cognitive decline in elderly hypertensive patients397Changes in connexin43 in old rats with volume overload chronic heart failureGenetics and epigenetics400Calcium content in the aortic valve is associated with 1G>2G matrix metalloproteinase 1 polymorphism401Neuropeptide receptor gene s (NPSR1) polymorphism and sleep disturbances402Endothelin-1 gene Lys198Asn polymorphism in men with essential hypertension complicated and uncomplicated with chronic heart failure403Association of common polymorphisms of the lipoprotein lipase and pon1 genes with the metabolic syndrome in a sample of community participantsGenomics, proteomics, metabolomics, lipidomics and glycomics405Gene expression quantification using multiplexed color-coded probe pairs to determine RNA content in sporadic cardiac myxoma406Large-scale phosphorylation study of the type 2 diabetic heart subjected to ischemia / reperfusion injury407Transcriptome-based identification of new anti-inflammatory properties of the olive oil hydroxytyrosol in vascular endothelial cell under basal and proinflammatory conditions408Gene polymorphisms combinations and risk of myocardial infarctionComputer modelling, bioinformatics and big data411Comparison of the repolarization reserve in three state-of-the-art models of the human ventricular action potentialMetabolism, diabetes mellitus and obesity414Endothelial monocyte-activating polypeptide-II improves heart function in type -I Diabetes mellitus415Admission glucose level is independent predictor of impaired left ventricular function in patients with acute myocardial infarction: a two dimensional speckle-tracking echocardiography study416Association between biochemical markers of lipid profile and inflammatory reaction and stiffness of the vascular wall in hypertensive patients with abdominal obesity417Multiple common co-morbidities produce left ventricular diastolic dysfunction associated with coronary microvascular dysfunction, oxidative stress and myocardial stiffening418Investigating the cardiovascular effects of antiretroviral drugs in a lean and high fat/sucrose diet rat model of obesity419Statins in the treatment of non-alcoholic steatohepatitis (NASH). Our experience from a 2-year prospective study in Constanta County, Romania420Epicardial adipose tissue as a predictor of cardiovascular outcome in patients with ACS undergoing PCI?Arterial and pulmonary hypertension423Dependence between heart rhythm disorers and ID polymorphism of ACE gene in hypertensive patients424Molecular mechanisms underlying the beneficial effects of Urocortin 2 in pulmonary arterial hypertension425Inhibition of TGf-b axis and action of renin-angiotensin system in human ascending aorta aneurysms426Early signs of microcirculation and macrocirculation abnormalities in prehypertension427Vascular smooth muscle cell-expressed Tie-2 controls vascular tone428Cardiac and vascular remodelling in the development of chronic thrombo-embolic pulmonary hypertension in a novel swine modelBiomarkers431Arrhythmogenic cardiomyopathy: a new, non invasive biomarker432Can circulating microRNAs distinguish type 1 and type 2 myocardial infarction?433Design of a high-throughput multiplex proteomics assay to identify left ventricular diastolic dysfunction in diabetes434Monocyte-derived and P-selectin-carrying microparticles are differently modified by a low fat diet in patients with cardiovascular risk factors who will and who will not develop a cardiovascular event435Red blood cell distribution width assessment by polychromatic interference microscopy of thin films in chronic heart failure436Invasive and noninvasive evaluation of quality of radiofrequency-induced cardiac denervation in patients with atrial fibrillation437The effect of therapeutic hypothermia on the level of brain derived neurotrophic factor (BDNF) in sera following cardiopulmonary resustitation438Novel biomarkers to predict outcome in patients with heart failure and severe aortic stenosis439Biological factors linking depression and anxiety to cardiovascular disease440Troponins and myoglobin dynamic at coronary arteries graftingInvasive, non-invasive and molecular imaging443Diet composition effects on the genetic typing of the mouse ob mutation: a micro-ultrasound characterization of cardiac function, macro and micro circulation and liver steatosis444Characterization of pig coronary and rabbit aortic lesions using IV-OCT quantitative analysis: correlations with histologyGene therapy and cell therapy447Enhancing the survival and angiogenic potential of mouse atrial mesenchymal cells448VCAM-1 expression in experimental myocardial infarction and its relation to bone marrow-derived mononuclear cell retentionTissue engineering451Advanced multi layered scaffold that increases the maturity of stem cell-derived human cardiomyocytes452Response of engineered heart tissue to simulated ischemia/reperfusion in the presence of acute hyperglycemic conditions453Serum albumin hydrogels prevent de-differentiation of neonatal cardiomyocytes454A novel paintbrush technique for transfer of low viscosity ultraviolet light curable cyan methacrylate on saline immersed in-vitro sheep heart. Cardiovasc Res 2016. [DOI: 10.1093/cvr/cvw149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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PI3K signaling in arterial diseases: Non redundant functions of the PI3K isoforms. Adv Biol Regul 2015; 59:4-18. [PMID: 26238239 DOI: 10.1016/j.jbior.2015.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/15/2015] [Accepted: 06/15/2015] [Indexed: 06/04/2023]
Abstract
Cardiovascular diseases are the most common cause of death around the world. This includes atherosclerosis and the adverse effects of its treatment, such as restenosis and thrombotic complications. The development of these arterial pathologies requires a series of highly-intertwined interactions between immune and arterial cells, leading to specific inflammatory and fibroproliferative cellular responses. In the last few years, the study of phosphoinositide 3-kinase (PI3K) functions has become an attractive area of investigation in the field of arterial diseases, especially since inhibitors of specific PI3K isoforms have been developed. The PI3K family includes 8 members divided into classes I, II or III depending on their substrate specificity. Although some of the different isoforms are responsible for the production of the same 3-phosphoinositides, they each have specific, non-redundant functions as a result of differences in expression levels in different cell types, activation mechanisms and specific subcellular locations. This review will focus on the functions of the different PI3K isoforms that are suspected as having protective or deleterious effects in both the various immune cells and types of cell found in the arterial wall. It will also discuss our current understanding in the context of which PI3K isoform(s) should be targeted for future therapeutic interventions to prevent or treat arterial diseases.
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The Activation Function-1 of Estrogen Receptor Alpha Prevents Arterial Neointima Development Through a Direct Effect on Smooth Muscle Cells. Circ Res 2015; 117:770-8. [PMID: 26316608 PMCID: PMC4596486 DOI: 10.1161/circresaha.115.306416] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 08/27/2015] [Indexed: 01/17/2023]
Abstract
RATIONALE 17β-Estradiol (E2) exerts numerous beneficial effects in vascular disease. It regulates gene transcription through nuclear estrogen receptor α (ERα) via 2 activation functions, AF1 and AF2, and can also activate membrane ERα. The role of E2 on the endothelium relies on membrane ERα activation, but the molecular mechanisms of its action on vascular smooth muscle cells (VSMCs) are not fully understood. OBJECTIVE The aim of this study was to determine which cellular target and which ERα subfunction are involved in the preventive action of E2 on neointimal hyperplasia. METHODS AND RESULTS To trigger neointimal hyperplasia of VSMC, we used a mouse model of femoral arterial injury. Cre-Lox models were used to distinguish between the endothelial- and the VSMC-specific actions of E2. The molecular mechanisms underlying the role of E2 were further characterized using both selective ERα agonists and transgenic mice in which the ERαAF1 function had been specifically invalidated. We found that (1) the selective inactivation of ERα in VSMC abrogates the neointimal hyperplasia protection induced by E2, whereas inactivation of endothelial and hematopoietic ERα has no effect; (2) the selective activation of membrane ERα does not prevent neointimal hyperplasia; and (3) ERαAF1 is necessary and sufficient to inhibit postinjury VSMC proliferation. CONCLUSIONS Altogether, ERαAF1-mediated nuclear action is both necessary and sufficient to inhibit postinjury arterial VSMC proliferation, whereas membrane ERα largely regulates the endothelial functions of E2. This highlights the exquisite cell/tissue-specific actions of the ERα subfunctions and helps to delineate the spectrum of action of selective ER modulators.
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Targeting PI3Kγ activity decreases vascular trauma-induced intimal hyperplasia through modulation of the Th1 response. ACTA ACUST UNITED AC 2014; 211:1779-92. [PMID: 25073791 PMCID: PMC4144742 DOI: 10.1084/jem.20131276] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Interventional strategies to treat atherosclerosis, such as transluminal angioplasty and stent implantation, often cause vascular injury. This leads to intimal hyperplasia (IH) formation that induces inflammatory and fibroproliferative processes and ultimately restenosis. We show that phosphoinositide 3-kinase γ (PI3Kγ) is a key player in IH formation and is a valid therapeutic target in its prevention/treatment. PI3Kγ-deficient mice and mice expressing catalytically inactive PI3Kγ (PI3Kγ KD) showed reduced arterial occlusion and accumulation of monocytes and T cells around sites of vascular lesion. The transfer of PI3Kγ KD CD4(+) T cells into Rag2-deficient mice greatly reduced vascular occlusion compared with WT cells, clearly demonstrating the involvement of PI3Kγ in CD4(+) T cells during IH formation. In addition we found that IH is associated with increased levels of Th1 and Th17 cytokines. A specific decrease in the Th1 response was observed in the absence of PI3Kγ activity, leading to decreased CXCL10 and RANTES production by smooth muscle cells. Finally, we show that treatment with the PI3Kγ inhibitor AS-605240 is sufficient to decrease IH in both mouse and rat models, reinforcing the therapeutic potential of PI3Kγ inhibition. Altogether, these findings demonstrate a new role for PI3Kγ activity in Th1-controlled IH development.
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Role of the ubiquitin-proteasome system in the regulation of P2Y13 receptor expression: impact on hepatic HDL uptake. Cell Mol Life Sci 2014; 71:1775-88. [PMID: 24030815 PMCID: PMC11113673 DOI: 10.1007/s00018-013-1471-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 08/28/2013] [Accepted: 08/30/2013] [Indexed: 01/03/2023]
Abstract
The protective effect of high density lipoproteins (HDL) against atherosclerosis is mainly attributed to their capacity to transport excess cholesterol from peripheral tissues back to the liver for further elimination into the bile, a process called reverse cholesterol transport (RCT). Recently, the importance of the P2Y13 receptor (P2Y13-R) was highlighted in HDL metabolism since HDL uptake by the liver was decreased in P2Y13-R deficient mice, which translated into impaired RCT. Here, we investigated for the first time the molecular mechanisms regulating cell surface expression of P2Y13-R. When transiently expressed, P2Y13-R was mainly detected in the endoplasmic reticulum (ER) and strongly subjected to proteasome degradation while its homologous P2Y12 receptor (P2Y12-R) was efficiently targeted to the plasma membrane. We observed an inverse correlation between cell surface expression and ubiquitination level of P2Y13-R in the ER, suggesting a close link between ubiquitination of P2Y13-R and its efficient targeting to the plasma membrane. The C-terminus tail exchange between P2Y13-R and P2Y12-R strongly restored plasma membrane expression of P2Y13-R, suggesting the involvement of the intra-cytoplasmic tail of P2Y13-R in expression defect. Accordingly, proteasomal inhibition increased plasma membrane expression of functionally active P2Y13-R in hepatocytes, and consequently stimulated P2Y13-R-mediated HDL endocytosis. Importantly, proteasomal inhibition strongly potentiated HDL hepatic uptake (>200 %) in wild-type but not in P2Y13-R-deficient mice, thus reinforcing the role of P2Y13-R expression in regulating HDL metabolism. Therefore, specific inhibition of the ubiquitin-proteasome system might be a novel powerful HDL therapy to enhance P2Y13-R expression and consequently promote the overall RCT.
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Abstract
AIMS Elastin is degraded during vascular ageing and its products, elastin-derived peptides (EP), are present in the human blood circulation. EP binds to the elastin receptor complex (ERC) at the cell surface, composed of elastin-binding protein (EBP), a cathepsin A and a neuraminidase 1. Some in vitro functions have clearly been attributed to this binding, but the in vivo implications for arterial diseases have never been clearly investigated. METHODS AND RESULTS Here, we demonstrate that chronic doses of EP injected into mouse models of atherosclerosis increase atherosclerotic plaque size formation. Similar effects were observed following an injection of a VGVAPG peptide, suggesting that the ERC mediates these effects. The absence of phosphoinositide 3-kinase γ (PI3Kγ) in bone marrow-derived cells prevented EP-induced atherosclerosis development, demonstrating that PI3Kγ drive EP-induced arterial lesions. Accordingly, in vitro studies showed that PI3Kγ was required for EP-induced monocyte migration and ROS production and that this effect was dependent upon neuraminidase activity. Finally, we showed that degradation of elastic lamellae in LDLR(-/-) mice fed an atherogenic diet correlated with atherosclerotic plaque formation. At the same time, the absence of the cathepsin A-neuraminidase 1 complex in cells of the haematopoietic lineage abolished atheroma plaque size progression and decreased leucocytes infiltration, clearly demonstrating the role of this complex in atherogenesis and suggesting the involvement of endogenous EP. CONCLUSION Altogether, this work identifies EP as an enhancer of atherogenesis and defines the Neuraminidase 1/PI3Kγ signalling pathway as a key mediator of this function in vitro and in vivo.
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Chronic pharmacological activation of P2Y13 receptor in mice decreases HDL-cholesterol level by increasing hepatic HDL uptake and bile acid secretion. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:719-25. [PMID: 23266391 DOI: 10.1016/j.bbalip.2012.12.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 12/10/2012] [Accepted: 12/12/2012] [Indexed: 11/16/2022]
Abstract
High level of high-density lipoprotein cholesterol (HDL-cholesterol) is inversely correlated to the risk of atherosclerotic cardiovascular disease. The protective effect of HDL is mostly attributed to their metabolic functions in reverse cholesterol transport (RCT), a process whereby excess cell cholesterol is taken up from peripheral cells and processed in HDL particles, and is later delivered to the liver for further metabolism and bile excretion. We have previously demonstrated that P2Y13 receptor is critical for RCT and that intravenous bolus injection of cangrelor (AR-C69931MX), a partial agonist of P2Y13 receptor, can stimulate hepatic HDL uptake and subsequent lipid biliary secretion without any change in plasma lipid levels. In the present study, we investigated the effect of longer-term treatment with cangrelor on lipoprotein metabolism in mice. We observed that continuous delivery of cangrelor at a rate of 35μg/day/kg body weight for 3days markedly decreased plasma HDL-cholesterol level, by increasing the clearance of HDL particles by the liver. These effects were correlated to an increase in the rate of biliary bile acid secretion. An increased expression of SREBP-regulated genes of cholesterol metabolism was also observed without any change of hepatic lipid levels as compared to non-treated mice. Thus, 3-day cangrelor treatment markedly increases the flux of HDL-cholesterol from the plasma to the liver for bile acid secretion. Taken together our results suggest that P2Y13 appears a promising target for therapeutic intervention aimed at preventing or reducing cardiovascular risk.
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Key role of PI3Kγ in monocyte chemotactic protein-1-mediated amplification of PDGF-induced aortic smooth muscle cell migration. Br J Pharmacol 2012; 166:1643-53. [PMID: 22251152 DOI: 10.1111/j.1476-5381.2012.01866.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Vascular smooth muscle cell (SMC) migration within the arterial wall is a crucial event in atherogenesis and restenosis. Monocyte chemotactic protein-1/CC-chemokine receptor 2 (MCP-1/CCR2) signalling is involved in SMC migration processes but the molecular mechanisms have not been well characterized. We investigated the role of PI3Kγ in SMC migration induced by MCP-1. EXPERIMENTAL APPROACHES A pharmacological PI3Kγ inhibitor, adenovirus encoding inactive forms of PI3Kγ and genetic deletion of PI3Kγ were used to investigate PI3Kγ functions in the MCP-1 and platelet-derived growth factor (PDGF) signalling pathway and migration process in primary aortic SMC. KEY RESULTS The γ isoform of PI3K was shown to be the major signalling molecule mediating PKB phosphorylation in MCP-1-stimulated SMC. Using a PI3Kγ inhibitor and an adenovirus encoding a dominant negative form of PI3Kγ, we demonstrated that PI3Kγ is essential for SMC migration triggered by MCP-1. PDGF receptor stimulation induced MCP-1 mRNA and protein accumulation in SMCs. Blockade of the MCP-1/CCR2 pathway or pharmacological inhibition of PI3Kγ reduced PDGF-stimulated aortic SMC migration by 50%. Thus PDGF promotes an autocrine loop involving MCP-1/CCR2 signalling which is required for PDGF-mediated SMC migration. Furthermore, SMCs isolated from PI3Kγ-deficient mice (PI3Kγ(-/-)), or mice expressing an inactive PI3Kγ (PI3Kγ(KD/KD)), migrated less than control cells in response to MCP-1 and PDGF. CONCLUSIONS AND IMPLICATIONS PI3Kγ is essential for MCP-1-stimulated aortic SMC migration and amplifies cell migration induced by PDGF by an autocrine/paracrine loop involving MCP-1 secretion and CCR2 activation. PI3Kγ is a promising target for the treatment of aortic fibroproliferative pathologies.
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Mitochondrial inhibitory factor 1 (IF1) is present in human serum and is positively correlated with HDL-cholesterol. PLoS One 2011; 6:e23949. [PMID: 21935367 PMCID: PMC3173369 DOI: 10.1371/journal.pone.0023949] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 07/28/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Mitochondrial ATP synthase is expressed as a plasma membrane receptor for apolipoprotein A-I (apoA-I), the major protein component in High Density Lipoproteins (HDL). On hepatocytes, apoA-I binds to cell surface ATP synthase (namely ecto-F(1)-ATPase) and stimulates its ATPase activity, generating extracellular ADP. This production of extracellular ADP activates a P2Y(13)-mediated HDL endocytosis pathway. Conversely, exogenous IF1, classically known as a natural mitochondrial specific inhibitor of F(1)-ATPase activity, inhibits ecto-F(1)-ATPase activity and decreases HDL endocytosis by both human hepatocytes and perfused rat liver. METHODOLOGY/PRINCIPAL FINDINGS Since recent reports also described the presence of IF1 at the plasma membrane of different cell types, we investigated whether IF1 is present in the systemic circulation in humans. We first unambiguously detected IF1 in human serum by immunoprecipitation and mass spectrometry. We then set up a competitive ELISA assay in order to quantify its level in human serum. Analyses of IF1 levels in 100 normolipemic male subjects evidenced a normal distribution, with a median value of 0.49 µg/mL and a 95% confidence interval of 0.22-0.82 µg/mL. Correlations between IF1 levels and serum lipid levels demonstrated that serum IF1 levels are positively correlated with HDL-cholesterol and negatively with triglycerides (TG). CONCLUSIONS/SIGNIFICANCE Altogether, these data support the view that, in humans, circulating IF1 might affect HDL levels by inhibiting hepatic HDL uptake and also impact TG metabolism.
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Absence of the lysophosphatidic acid receptor LPA1 results in abnormal bone development and decreased bone mass. Bone 2011; 49:395-403. [PMID: 21569876 PMCID: PMC3697734 DOI: 10.1016/j.bone.2011.04.018] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 04/07/2011] [Accepted: 04/20/2011] [Indexed: 11/18/2022]
Abstract
Lysophosphatidic acid (LPA) is a lipid mediator that acts in paracrine systems via interaction with a subset of G protein-coupled receptors (GPCRs). LPA promotes cell growth and differentiation, and has been shown to be implicated in a variety of developmental and pathophysiological processes. At least 6 LPA GPCRs have been identified to date: LPA1-LPA6. Several studies have suggested that local production of LPA by tissues and cells contributes to paracrine regulation, and a complex interplay between LPA and its receptors, LPA1 and LPA4, is believed to be involved in the regulation of bone cell activity. In particular, LPA1 may activate both osteoblasts and osteoclasts. However, its role has not as yet been examined with regard to the overall status of bone in vivo. We attempted to clarify this role by defining the bone phenotype of LPA1((-/-)) mice. These mice demonstrated significant bone defects and low bone mass, indicating that LPA1 plays an important role in osteogenesis. The LPA1((-/-)) mice also presented growth and sternal and costal abnormalities, which highlights the specific roles of LPA1 during bone development. Microcomputed tomography and histological analysis demonstrated osteoporosis in the trabecular and cortical bone of LPA1((-/-)) mice. Finally, bone marrow mesenchymal progenitors from these mice displayed decreased osteoblastic differentiation. These results suggest that LPA1 strongly influences bone development both qualitatively and quantitatively and that, in vivo, its absence results in decreased osteogenesis with no clear modification of osteoclasis. They open perspectives for a better understanding of the role of the LPA/LPA1 paracrine pathway in bone pathophysiology.
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