RESUMEN
Colchicine is a broad-acting anti-inflammatory agent that has attracted interest for repurposing in atherosclerotic cardiovascular disease. Here, we studied its ability at a human equivalent dose of 0.5 mg/day to modify plaque formation and composition in murine atherosclerosis and investigated its actions on macrophage responses to atherogenic stimuli in vitro. In atherosclerosis induced by high-cholesterol diet, Apoe-/- mice treated with colchicine had 50% reduction in aortic oil Red O+ plaque area compared to saline control (p = .001) and lower oil Red O+ staining of aortic sinus lesions (p = .03). In vitro, addition of 10 nM colchicine inhibited foam cell formation from murine and human macrophages after treatment with oxidized LDL (ox-LDL). Mechanistically, colchicine downregulated glycosylation and surface expression of the ox-LDL uptake receptor, CD36, and reduced CD36+ staining in aortic sinus plaques. It also decreased macrophage uptake of cholesterol crystals, resulting in lower intracellular lysosomal activity, inhibition of the NLRP3 inflammasome, and reduced secretion of IL-1ß and IL-18. Colchicine's anti-atherosclerotic actions were accentuated in a mouse model of unstable plaque induced by carotid artery tandem stenosis surgery, where it decreased lesion size by 48% (p = .01), reduced lipid (p = .006) and necrotic core area (p = .007), increased collagen content and cap-to-necrotic core ratio (p = .05), and attenuated plaque neutrophil extracellular traps (p < .001). At low dose, colchicine's effects were not accompanied by the evidence of microtubule depolymerization. Together, these results show that colchicine exerts anti-atherosclerotic and plaque-stabilizing effects at low dose by inhibiting foam cell formation and cholesterol crystal-induced inflammation. This provides a new framework to support its repurposing for atherosclerotic cardiovascular disease.
Asunto(s)
Aterosclerosis , Enfermedades Cardiovasculares , Estenosis Carotídea , Humanos , Animales , Ratones , Células Espumosas , Colchicina , ColesterolRESUMEN
Eukaryotic elongation factor 2 kinase (eEF2K) is an atypical protein kinase that controls protein synthesis in cells under stress. Although well studied in cancer, less is known about its roles in chronic inflammatory diseases. Here, we examined its regulation of macrophage cholesterol handling in the context of atherosclerosis. eEF2K mRNA expression and protein activity were upregulated in murine bone marrow-derived macrophages (BMDMs) exposed to oxidized low-density lipoprotein cholesterol (oxLDL). When incubated with oxLDL, BMDMs from eEF2K knockout (Eef2k-/- ) mice formed fewer Oil Red O+ foam cells than Eef2k+/+ BMDMs (12.5% ± 2.3% vs. 32.3% ± 2.0%, p < .01). Treatment with a selective eEF2K inhibitor, JAN-384, also decreased foam cell formation for C57BL/6J BMDMs and human monocyte-derived macrophages. Disabling eEF2K selectively decreased protein expression of the CD36 cholesterol uptake receptor, mediated by a reduction in the proportion of translationally active Cd36 mRNA. Eef2k-/- mice bred onto the Ldlr-/- background developed aortic sinus atherosclerotic plaques that were 30% smaller than Eef2k+/+ -Ldlr-/- mice after 16 weeks of high cholesterol diet (p < .05). Although accompanied by a reduction in plaque CD36+ staining (p < .05) and lower CD36 expression in circulating monocytes (p < .01), this was not associated with reduced lipid content in plaques as measured by oil red O staining. Finally, EEF2K and CD36 mRNA levels were higher in blood mononuclear cells from patients with coronary artery disease and recent myocardial infarction compared to healthy controls without coronary artery disease. These results reveal a new role for eEF2K in translationally regulating CD36 expression and foam cell formation in macrophages. Further studies are required to explore therapeutic targeting of eEF2K in atherosclerosis.
Asunto(s)
Antígenos CD36/metabolismo , Quinasa del Factor 2 de Elongación/metabolismo , Células Espumosas/metabolismo , Animales , Aterosclerosis/metabolismo , Colesterol/metabolismo , Enfermedad de la Arteria Coronaria/metabolismo , Femenino , Humanos , Leucocitos Mononucleares/metabolismo , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Monocitos/metabolismo , Placa Aterosclerótica/metabolismo , ARN Mensajero/metabolismo , Transducción de Señal/fisiologíaRESUMEN
Converging evidence indicates that extra-embryonic yolk sac is the source of both macrophages and endothelial cells in adult mouse tissues. Prevailing views are that these embryonically derived cells are maintained after birth by proliferative self-renewal in their differentiated states. Here we identify clonogenic endothelial-macrophage (EndoMac) progenitor cells in the adventitia of embryonic and postnatal mouse aorta, that are independent of Flt3-mediated bone marrow hematopoiesis and derive from an early embryonic CX3CR1+ and CSF1R+ source. These bipotent progenitors are proliferative and vasculogenic, contributing to adventitial neovascularization and formation of perfused blood vessels after transfer into ischemic tissue. We establish a regulatory role for angiotensin II, which enhances their clonogenic and differentiation properties and rapidly stimulates their proliferative expansion in vivo. Our findings demonstrate that embryonically derived EndoMac progenitors participate in local vasculogenic responses in the aortic wall by contributing to the expansion of endothelial cells and macrophages postnatally.
Asunto(s)
Aorta , Macrófagos , Animales , Macrófagos/citología , Macrófagos/metabolismo , Aorta/citología , Ratones , Receptor 1 de Quimiocinas CX3C/metabolismo , Receptor 1 de Quimiocinas CX3C/genética , Células Endoteliales/citología , Células Endoteliales/metabolismo , Diferenciación Celular , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Angiotensina II , Proliferación Celular , Células Madre/citología , Células Madre/metabolismo , Ratones Endogámicos C57BL , Femenino , Neovascularización Fisiológica , Receptores de Quimiocina/metabolismo , Receptores de Quimiocina/genética , Masculino , Hematopoyesis/fisiología , Tirosina Quinasa 3 Similar a fmsRESUMEN
Atherosclerotic coronary artery disease (CAD) results from build-up of cholesterol-rich plaques in the walls of the coronary arteries and is a leading cause of death. Inflammation is central to atherosclerosis. Uncontrolled inflammation makes coronary plaques "unstable" and vulnerable to rupture or erosion, leading to thrombosis and myocardial infarction (MI). As multiple inflamed plaques often co-exist in the coronary system, patients are at risk of repeated atherothrombotic cardiovascular events after MI, with rates of 10-12% at one year and 18-20% at three years. This is largely because current therapies for CAD, such as lipid-lowering statins, do not adequately control plaque inflammation. New anti-atherosclerotic agents are therefore needed, especially those that better target inflammation. The recent positive results for the anti-interleukin-1-beta (IL-1ß) monoclonal antibody, Canakinumab, in the Canakinumab Anti-inflammatory Thrombosis Outcome Study (CANTOS) clinical trial has provided a major stimulant to the field. It highlights that not only is inflammation important from a pathogenic and risk prediction perspective in CAD, but that reducing inflammation can be beneficial. The challenge is now to find the best strategies to achieve this in real-world practice. This review outlines the role that inflammation plays in atherosclerosis and provides an update on anti-inflammatory therapies currently being investigated to target atherosclerosis.
RESUMEN
The cellular origins of vasa vasorum are ill-defined and may involve circulating or local progenitor cells. We previously discovered that murine aortic adventitia contains Sca-1+CD45+ progenitors that produce macrophages. Here we investigated whether they are also vasculogenic. In aortas of C57BL/6 mice, Sca-1+CD45+ cells were localised to adventitia and lacked surface expression of endothelial markers (<1% for CD31, CD144, TIE-2). In contrast, they did show expression of CD31, CD144, TIE-2 and VEGFR2 in atherosclerotic ApoE-/- aortas. Although Sca-1+CD45+ cells from C57BL/6 aorta did not express CD31, they formed CD31+ colonies in endothelial differentiation media and produced interconnecting vascular-like cords in Matrigel that contained both endothelial cells and a small population of macrophages, which were located at branch points. Transfer of aortic Sca-1+CD45+ cells generated endothelial cells and neovessels de novo in a hindlimb model of ischaemia and resulted in a 50% increase in perfusion compared to cell-free control. Similarly, their injection into the carotid adventitia of ApoE-/- mice produced donor-derived adventitial and peri-adventitial microvessels after atherogenic diet, suggestive of newly formed vasa vasorum. These findings show that beyond its content of macrophage progenitors, adventitial Sca-1+CD45+ cells are also vasculogenic and may be a source of vasa vasorum during atherogenesis.