Joëlle Magné1, Peter Gustafsson2, Hong Jin2, Lars Maegdefessel2, Kjell Hultenby2, Annika Wernerson2, Per Eriksson2, Anders Franco-Cereceda2, Petri T Kovanen2, Isabel Gonçalves2, Ewa Ehrenborg2. 1. From the Atherosclerosis Research Unit, Department of Medicine, Center for Molecular Medicine, Karolinska University Hospital (J.M., P.G., H.J., L.M., P.E., E.E.), Division of Clinical Research Center, Department of Laboratory Medicine (K.H.), Division of Renal Medicine, Department of Clinical Science, Technology and Intervention (A.W.), Cardiothoracic Surgery Unit, Department of Molecular Medicine and Surgery (A.F.-C.), Karolinska Institutet, Stockholm, Sweden; Wihuri Research Institute, Helsinki, Finland (P.T.K.); and Experimental Cardiovascular Research Group and Cardiology Department, Skåne University Hospital, Clinical Research Center, Clinical Sciences Malmö, Lund University, Sweden (I.G.). joelle.magne@ki.se. 2. From the Atherosclerosis Research Unit, Department of Medicine, Center for Molecular Medicine, Karolinska University Hospital (J.M., P.G., H.J., L.M., P.E., E.E.), Division of Clinical Research Center, Department of Laboratory Medicine (K.H.), Division of Renal Medicine, Department of Clinical Science, Technology and Intervention (A.W.), Cardiothoracic Surgery Unit, Department of Molecular Medicine and Surgery (A.F.-C.), Karolinska Institutet, Stockholm, Sweden; Wihuri Research Institute, Helsinki, Finland (P.T.K.); and Experimental Cardiovascular Research Group and Cardiology Department, Skåne University Hospital, Clinical Research Center, Clinical Sciences Malmö, Lund University, Sweden (I.G.).
Abstract
OBJECTIVE: Autophagy has emerged as a cell survival mechanism critical for cellular homeostasis, which may play a protective role in atherosclerosis. ATG16L1, a protein essential for early stages of autophagy, has been implicated in the pathogenesis of Crohn's disease. However, it is unknown whether ATG16L1 is involved in atherosclerosis. Our aim was to analyze ATG16L1 expression in carotid atherosclerotic plaques in relation to markers of plaque vulnerability. APPROACH AND RESULTS: Histological analysis of 143 endarterectomized human carotid atherosclerotic plaques revealed that ATG16L1 was expressed in areas surrounding the necrotic core and the shoulder regions. Double immunofluorescence labeling revealed that ATG16L1 was abundantly expressed in phagocytic cells (CD68), endothelial cells (CD31), and mast cells (tryptase) in human advanced plaques. ATG16L1 immunogold labeling was predominantly observed in endothelial cells and foamy smooth muscle cells of the plaques. ATG16L1 protein expression correlated with plaque content of proinflammatory cytokines and matrix metalloproteinases. Analysis of Atg16L1 at 2 distinct stages of the atherothrombotic process in a murine model of plaque vulnerability by incomplete ligation and cuff placement in carotid arteries of apolipoprotein-E-deficient mice revealed a strong colocalization of Atg16L1 and smooth muscle cells only in early atherosclerotic lesions. An increase in ATG16L1 expression and autophagy flux was observed during foam cell formation in human macrophages using oxidized-LDL. CONCLUSIONS: Taken together, this study shows that ATG16L1 protein expression is associated with foam cell formation and inflamed plaque phenotype and could contribute to the development of plaque vulnerability at earlier stages of the atherogenic process.
OBJECTIVE: Autophagy has emerged as a cell survival mechanism critical for cellular homeostasis, which may play a protective role in atherosclerosis. ATG16L1, a protein essential for early stages of autophagy, has been implicated in the pathogenesis of Crohn's disease. However, it is unknown whether ATG16L1 is involved in atherosclerosis. Our aim was to analyze ATG16L1 expression in carotid atherosclerotic plaques in relation to markers of plaque vulnerability. APPROACH AND RESULTS: Histological analysis of 143 endarterectomized human carotid atherosclerotic plaques revealed that ATG16L1 was expressed in areas surrounding the necrotic core and the shoulder regions. Double immunofluorescence labeling revealed that ATG16L1 was abundantly expressed in phagocytic cells (CD68), endothelial cells (CD31), and mast cells (tryptase) in human advanced plaques. ATG16L1 immunogold labeling was predominantly observed in endothelial cells and foamy smooth muscle cells of the plaques. ATG16L1 protein expression correlated with plaque content of proinflammatory cytokines and matrix metalloproteinases. Analysis of Atg16L1 at 2 distinct stages of the atherothrombotic process in a murine model of plaque vulnerability by incomplete ligation and cuff placement in carotid arteries of apolipoprotein-E-deficient mice revealed a strong colocalization of Atg16L1 and smooth muscle cells only in early atherosclerotic lesions. An increase in ATG16L1 expression and autophagy flux was observed during foam cell formation in human macrophages using oxidized-LDL. CONCLUSIONS: Taken together, this study shows that ATG16L1 protein expression is associated with foam cell formation and inflamed plaque phenotype and could contribute to the development of plaque vulnerability at earlier stages of the atherogenic process.
Authors: Hong Jin; Daniel Y Li; Ekaterina Chernogubova; Changyan Sun; Albert Busch; Suzanne M Eken; Peter Saliba-Gustafsson; Hanna Winter; Greg Winski; Uwe Raaz; Isabel N Schellinger; Nancy Simon; Renate Hegenloh; Ljubica Perisic Matic; Maja Jagodic; Ewa Ehrenborg; Jaroslav Pelisek; Hans-Henning Eckstein; Ulf Hedin; Alexandra Backlund; Lars Maegdefessel Journal: Mol Ther Date: 2018-01-31 Impact factor: 11.454
Authors: Karen Vrijens; Ellen Winckelmans; Maria Tsamou; Willy Baeyens; Patrick De Boever; Danyel Jennen; Theo M de Kok; Elly Den Hond; Wouter Lefebvre; Michelle Plusquin; Hans Reynders; Greet Schoeters; Nicolas Van Larebeke; Charlotte Vanpoucke; Jos Kleinjans; Tim S Nawrot Journal: Environ Health Perspect Date: 2016-10-14 Impact factor: 9.031