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Activation of endothelial autophagy is required for endothelial alignment in flow and atheroprotective signaling
UntitledBook1.book Page 183 Monday, March 20, 2017 2:28 PM
183
Archives of Cardiovascular Diseases Supplements (2017) 9, 183-184
Topic 16 – Atherosclerosis, thrombosis, hemostasis April 07th, Friday 2017
321 Activation of endothelial autophagy is required for endothelial alignment in flow and atheroprotective signaling M. Kheloufi* (1), AC. Vion (1), A. Hammoutene (1), J. Poisson (1), J. Lasselin (1), C. Devue (1), N. Dupont (2), J. Pierre (3), A. Tedgui (1-3), X. Loyer (1), B. Viollet (3), P. Codogno (2-3), C. Boulanger (1), PE. Rautou (1) (1) INSERM u970, PARIS – (2) CNRS: UMR8104, Paris, France – (3) INSERM U845, Necker Growth and Signaling Research Center – (4) Université Paris Descartes, Sorbonne Paris Cité, Paris, France – (5) CNRS; UMR7622, Paris, France *Corresponding author: [email protected] Blood flow-induced shear stress is a major determinant of atherosclerotic plaque localization, but the mechanisms are elusive. Here, we demonstrated in human and murine arteries that atheroprotective high shear stress activates endothelial autophagic flux. On the contrary, endothelial cells exposed to atheroprone low shear stress were characterized by inefficient autophagy resulting from mTOR activation, AMPKα inhibition and blockade of the autophagic flux. Strikingly, in hypercholesterolemic mice, deficiency in endothelial autophagy increased plaque burden in normally atheroresistant areas exposed to high shear stress. This effect was associated with a poor alignment of endothelial cells, and an increased endothelial apoptosis and senescence in high shear stress areas in transgenic mice deficient in endothelial autophagy. Moreover, cultured endothelial cells deficient in autophagy exposed to high shear stress and TNFα displayed an enhanced inflammatory response. Altogether, adequate endothelial autophagic flux under high shear stress limits atherosclerotic plaque formation by preventing endothelial apoptosis, senescence and inflammation. The author hereby declares no conflict of interest
441 Coronary and extra-coronary atherosclerotic development is associated with an increase inflammation and thrombin generation markers: a substudy of ACCTHEROMA Clinical Trial S. Kautbally* (1), A. Lerigoleur (1), S. Lepropre (1), B. Gerber (1), J. Kefer (1), S. Eeckhoudt (2), C. Oury (3), JL. Vanoverschelde (1), L. Bertrand (1), S. Horman (1), C. Beauloye (1) (1) Institut de Recherche Expérimentale et Clinique, Pole de recherche Cardiovasculaire, Université Catholique de Louvain – (2) Laboratoire d’hémostase, Cliniques Universitaires Saint-Luc, Bruxelles – (3) GIGA Research, Université de Liège, Liege, Belgique *Corresponding author: [email protected] Background Atherosclerosis is a chronic inflammatory disease of the arterial wall. Clinical evidence of the activation of inflammation and coagulation pathway, though undoubtedly involved in atherosclerotic progression and vascular calcification, remains limited. To our knowledge, few studies have assessed thrombin generation (TG) markers in coronary artery disease (CAD) while taking into account the extra-coronary atherosclerotic plaque burden. Aims.In the current substudy of the prospective ACCTHEROMA Clinical Trial, we sought to analyze the relationship between inflammation (HsCRP), TG markers and global atherosclerotic plaque burden in patients admitted for coronary angiogram. Methods A total of 188 consecutive patients (65±12years) were included from March 2015 to February 2016 in the ACCTHEROMA Clinical Trial. A randomly selected subgroup of 68 patients underwent thoraco-abdominal
scanner with prospective ECG-gating for calcium scoring on coronary(CAC Agatston Score) and extra-coronary arteries(Aortic calcification score – AoC). CAC was graded as mild(Agatston <100), moderate(Agatston 100-400) and severe(Agatston >400). We perform quartile analysis for AoC score. Blood samples were drawn after sheath insertion at the cath lab and plasma were snapped frozen for further analysis of TG (D-dimers, thrombin-antithrombin complex-TATc, prothrombin fragment 1.2 – F1.2) and inflammation markers (HsCRP). Results CAC Agatston score was correlated with AoC score (r=0,484, p<0,001). TG markers increased significantly with growing severity of coronary atherosclerotic plaque burden (p<0,001). Significant positive correlations were observed between steadily increasing AoC score and TG markers (Ddimers: r=0,254, p=0,040; TATc: r=0,365, p=0,002; F1.2: r=0,336, p=0,005). HsCRP was correlated with TG markers and increased significantly across AoC quartiles (p=0,040). However, these markers were poorly associated with the severity of clinical presentation of CAD (no significant increase in patients with acute coronary syndrome). Conclusions. This study provides clinical evidence of the pivotal role of inflammation and thrombin formation in the pathophysiology of atherosclerotic development. The limitation of these markers in detecting patients at high ischemic risk supports the need for novel biomarkers. The author hereby declares no conflict of interest
445 Platelet Acetyl-CoA Carboxylase phosphorylation: a potential marker for atherothrombotic coronary artery disease S. Kautbally* (1), S. Lepropre (1), A. Lerigoleur (1), B. Gerber (1), J. Kefer (1), D. Castanares (1), S. Eeckhoudt (2), C. Oury (3), JL. Vanoverschelde (1), L. Bertrand (1), S. Horman (1), C. Beauloye (1) (1) Institut de Recherche Expérimentale et Clinique, Pole de recherche Cardiovasculaire, Université Catholique de Louvain – (2) Laboratoire d’hémostase, Cliniques Universitaires Saint-Luc, Bruxelles – (3) GIGA Research, Université de Liège, Liege, Belgique *Corresponding author: [email protected] Introduction.Acetyl-CoA Carboxylase (ACC), the downstream specific substrate of the AMP-activated protein kinase, is mainly phosphorylated in response to thrombin compared to other platelet agonists. In clinical situation, such as coronary artery disease (CAD), associated with thrombin generation, ACC phosphorylation (P-ACC) can be an interesting marker of thrombin action on platelets. Platelet P-ACC can help us better understand the complex interplay between platelet activation and thrombin formation in CAD.Aims. In the current prospective clinical trial (ACCTHEROMA), we sought to investigate platelet P-ACC as a marker of atherothrombotic CAD. Methods A total of 188 consecutive patients (65±12 years) admitted for coronary angiogram were included from March 2015 to February 2016. Blood samples were drawn immediately after sheath insertion at the cath lab. Platelets were isolated and protein extracts were stocked frozen for further analysis by immunobloting and electrochemiluminescence (ECLIA test). CAD was assessed in all patients by coronary angiogram. Global atherosclerotic burden was evaluated by coronary (CAC Agatston score) and extra-coronary (AorticAoC score) calcification score on thoraco-abdominal scanner with prospective ECG-gating in a randomly selected subgroup of patients (n=68). Results Platelet P-ACC increases with growing severity of CAC Agatston score (CAC score <100: 0, 24 ± 0, 09 versus CAC score >400: 0, 31 ± 0, 10; p=0, 01). Moreover, patients with demonstrated CAD (CAC Agatston score >100 and/ or at least 1 vessel disease on the angiogram) have higher platelet P-ACC compared to non-CAD (0, 51 ± 0, 02 versus 0, 30 ± 0, 03 respectively; p<0,001). Quartile analysis of platelet P-ACC revealed a significantly higher proportion of patients (45%) with unstable CAD (acute coronary syndrome) in the 4th quartile (p=0, 01). More importantly, after adjusting for established cardiovascular risks factors, platelet P-ACC was an independent predictor of unstable CAD (odds ratio: 7.03, p=0,001). Likewise, ECLIA test shows significant correlation with immunobloting for platelet P-ACC analysis (r=0,574, p<0,001). Conclusions. Platelet P-ACC is a potential marker for screening patients with CAD at high ischemic risk. Optimizing ECLIA test for platelet P-ACC analysis seems to be a promising tool for future clinical studies. The author hereby declares no conflict of interest
© Elsevier Masson SAS. All rights reserved.
183
Archives of Cardiovascular Diseases Supplements (2017) 9, 183-184
Topic 16 – Atherosclerosis, thrombosis, hemostasis April 07th, Friday 2017
321 Activation of endothelial autophagy is required for endothelial alignment in flow and atheroprotective signaling M. Kheloufi* (1), AC. Vion (1), A. Hammoutene (1), J. Poisson (1), J. Lasselin (1), C. Devue (1), N. Dupont (2), J. Pierre (3), A. Tedgui (1-3), X. Loyer (1), B. Viollet (3), P. Codogno (2-3), C. Boulanger (1), PE. Rautou (1) (1) INSERM u970, PARIS – (2) CNRS: UMR8104, Paris, France – (3) INSERM U845, Necker Growth and Signaling Research Center – (4) Université Paris Descartes, Sorbonne Paris Cité, Paris, France – (5) CNRS; UMR7622, Paris, France *Corresponding author: [email protected] Blood flow-induced shear stress is a major determinant of atherosclerotic plaque localization, but the mechanisms are elusive. Here, we demonstrated in human and murine arteries that atheroprotective high shear stress activates endothelial autophagic flux. On the contrary, endothelial cells exposed to atheroprone low shear stress were characterized by inefficient autophagy resulting from mTOR activation, AMPKα inhibition and blockade of the autophagic flux. Strikingly, in hypercholesterolemic mice, deficiency in endothelial autophagy increased plaque burden in normally atheroresistant areas exposed to high shear stress. This effect was associated with a poor alignment of endothelial cells, and an increased endothelial apoptosis and senescence in high shear stress areas in transgenic mice deficient in endothelial autophagy. Moreover, cultured endothelial cells deficient in autophagy exposed to high shear stress and TNFα displayed an enhanced inflammatory response. Altogether, adequate endothelial autophagic flux under high shear stress limits atherosclerotic plaque formation by preventing endothelial apoptosis, senescence and inflammation. The author hereby declares no conflict of interest
441 Coronary and extra-coronary atherosclerotic development is associated with an increase inflammation and thrombin generation markers: a substudy of ACCTHEROMA Clinical Trial S. Kautbally* (1), A. Lerigoleur (1), S. Lepropre (1), B. Gerber (1), J. Kefer (1), S. Eeckhoudt (2), C. Oury (3), JL. Vanoverschelde (1), L. Bertrand (1), S. Horman (1), C. Beauloye (1) (1) Institut de Recherche Expérimentale et Clinique, Pole de recherche Cardiovasculaire, Université Catholique de Louvain – (2) Laboratoire d’hémostase, Cliniques Universitaires Saint-Luc, Bruxelles – (3) GIGA Research, Université de Liège, Liege, Belgique *Corresponding author: [email protected] Background Atherosclerosis is a chronic inflammatory disease of the arterial wall. Clinical evidence of the activation of inflammation and coagulation pathway, though undoubtedly involved in atherosclerotic progression and vascular calcification, remains limited. To our knowledge, few studies have assessed thrombin generation (TG) markers in coronary artery disease (CAD) while taking into account the extra-coronary atherosclerotic plaque burden. Aims.In the current substudy of the prospective ACCTHEROMA Clinical Trial, we sought to analyze the relationship between inflammation (HsCRP), TG markers and global atherosclerotic plaque burden in patients admitted for coronary angiogram. Methods A total of 188 consecutive patients (65±12years) were included from March 2015 to February 2016 in the ACCTHEROMA Clinical Trial. A randomly selected subgroup of 68 patients underwent thoraco-abdominal
scanner with prospective ECG-gating for calcium scoring on coronary(CAC Agatston Score) and extra-coronary arteries(Aortic calcification score – AoC). CAC was graded as mild(Agatston <100), moderate(Agatston 100-400) and severe(Agatston >400). We perform quartile analysis for AoC score. Blood samples were drawn after sheath insertion at the cath lab and plasma were snapped frozen for further analysis of TG (D-dimers, thrombin-antithrombin complex-TATc, prothrombin fragment 1.2 – F1.2) and inflammation markers (HsCRP). Results CAC Agatston score was correlated with AoC score (r=0,484, p<0,001). TG markers increased significantly with growing severity of coronary atherosclerotic plaque burden (p<0,001). Significant positive correlations were observed between steadily increasing AoC score and TG markers (Ddimers: r=0,254, p=0,040; TATc: r=0,365, p=0,002; F1.2: r=0,336, p=0,005). HsCRP was correlated with TG markers and increased significantly across AoC quartiles (p=0,040). However, these markers were poorly associated with the severity of clinical presentation of CAD (no significant increase in patients with acute coronary syndrome). Conclusions. This study provides clinical evidence of the pivotal role of inflammation and thrombin formation in the pathophysiology of atherosclerotic development. The limitation of these markers in detecting patients at high ischemic risk supports the need for novel biomarkers. The author hereby declares no conflict of interest
445 Platelet Acetyl-CoA Carboxylase phosphorylation: a potential marker for atherothrombotic coronary artery disease S. Kautbally* (1), S. Lepropre (1), A. Lerigoleur (1), B. Gerber (1), J. Kefer (1), D. Castanares (1), S. Eeckhoudt (2), C. Oury (3), JL. Vanoverschelde (1), L. Bertrand (1), S. Horman (1), C. Beauloye (1) (1) Institut de Recherche Expérimentale et Clinique, Pole de recherche Cardiovasculaire, Université Catholique de Louvain – (2) Laboratoire d’hémostase, Cliniques Universitaires Saint-Luc, Bruxelles – (3) GIGA Research, Université de Liège, Liege, Belgique *Corresponding author: [email protected] Introduction.Acetyl-CoA Carboxylase (ACC), the downstream specific substrate of the AMP-activated protein kinase, is mainly phosphorylated in response to thrombin compared to other platelet agonists. In clinical situation, such as coronary artery disease (CAD), associated with thrombin generation, ACC phosphorylation (P-ACC) can be an interesting marker of thrombin action on platelets. Platelet P-ACC can help us better understand the complex interplay between platelet activation and thrombin formation in CAD.Aims. In the current prospective clinical trial (ACCTHEROMA), we sought to investigate platelet P-ACC as a marker of atherothrombotic CAD. Methods A total of 188 consecutive patients (65±12 years) admitted for coronary angiogram were included from March 2015 to February 2016. Blood samples were drawn immediately after sheath insertion at the cath lab. Platelets were isolated and protein extracts were stocked frozen for further analysis by immunobloting and electrochemiluminescence (ECLIA test). CAD was assessed in all patients by coronary angiogram. Global atherosclerotic burden was evaluated by coronary (CAC Agatston score) and extra-coronary (AorticAoC score) calcification score on thoraco-abdominal scanner with prospective ECG-gating in a randomly selected subgroup of patients (n=68). Results Platelet P-ACC increases with growing severity of CAC Agatston score (CAC score <100: 0, 24 ± 0, 09 versus CAC score >400: 0, 31 ± 0, 10; p=0, 01). Moreover, patients with demonstrated CAD (CAC Agatston score >100 and/ or at least 1 vessel disease on the angiogram) have higher platelet P-ACC compared to non-CAD (0, 51 ± 0, 02 versus 0, 30 ± 0, 03 respectively; p<0,001). Quartile analysis of platelet P-ACC revealed a significantly higher proportion of patients (45%) with unstable CAD (acute coronary syndrome) in the 4th quartile (p=0, 01). More importantly, after adjusting for established cardiovascular risks factors, platelet P-ACC was an independent predictor of unstable CAD (odds ratio: 7.03, p=0,001). Likewise, ECLIA test shows significant correlation with immunobloting for platelet P-ACC analysis (r=0,574, p<0,001). Conclusions. Platelet P-ACC is a potential marker for screening patients with CAD at high ischemic risk. Optimizing ECLIA test for platelet P-ACC analysis seems to be a promising tool for future clinical studies. The author hereby declares no conflict of interest
© Elsevier Masson SAS. All rights reserved.