Research Paper Volume 11, Issue 11 pp 3832—3850
Knockdown of angiopoietin-like 2 induces clearance of vascular endothelial senescent cells by apoptosis, promotes endothelial repair and slows atherogenesis in mice
- 1 Faculty of Medicine, Department of Pharmacology and Physiology, Université de Montréal, Montreal, Quebec, Canada
- 2 Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada
- 3 Faculty of Medicine, Department of Biochemistry, Université de Montréal and CRCHUM, Montreal, Quebec, Canada
- 4 Faculty of Medicine, Department of Surgery, Université de Montréal, Montreal, Quebec, Canada
received: February 21, 2019 ; accepted: June 4, 2019 ; published: June 11, 2019 ;https://doi.org/10.18632/aging.102020
How to Cite
Copyright: Caland et al. This is an open‐access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Elimination of senescent cells (SnC) is anti-atherogenic, but the specific contribution of senescent vascular endothelial cells (EC) is unknown. We inactivated angiopoietin like-2 (angptl2), a marker of SnEC and a pro-atherogenic cytokine in LDLr-/-, hApoB100+/+ atherosclerotic (ATX) mice. Three months after a single vascular delivery of a small hairpin (sh)Angptl2 in 3-month old ATX mice using an adeno-associated virus serotype 1 (AAV1), aortic atheroma plaque progression was slowed by 58% (p<0.0001). In the native aortic endothelium, angptl2 expression was decreased by 80%, in association with a reduced expression of p21, a cyclin-dependent kinase inhibitor overexpressed in growth-arrested SnC. Endothelial activation was reduced (lower Icam-1, Il-1β and Mcp-1 expression), decreasing monocyte Cd68 expression in the endothelium. One week post-injection, the ratio Bax/Bcl2 increased in the endothelium only, suggesting that angptl2+/p21+ SnEC were eliminated by apoptosis. Four weeks post-injection, the endothelial progenitor marker Cd34 increased, suggesting endothelial repair. In arteries of atherosclerotic patients, we observed a strong correlation between p21 and ANGPTL2 (r=0.727, p=0.0002) confirming the clinical significance of angptl2-associated senescence. Our data suggest that therapeutic down-regulation of vascular angptl2 leads to the clearance of SnEC by apoptosis, stimulates endothelial repair and reduces atherosclerosis.
AAV1: adeno-associated virus serotype 1; ACEi: angiotensin converting enzyme inhibitors; Angptl2: angiopoietin-like 2: ARA, angiotensin II receptor antagonists; ATX: dyslipidemic LDLr-/-; ApoB100+/+: spontaneously atherosclerotic mice; Bax: Bcl-2-associated X protein; Bcl2: B-cell lymphoma 2; BMI: body mass index; CAD: coronary artery disease; CD34: Cluster of Differentiation 34; CD68: Cluster of Differentiation 68; COPD: chronic obstructive pulmonary disease; CVD: cardiovascular diseases; EC: endothelial cells; HbA1C: glycated hemoglobin A1C; ICAM-1: intracellular adhesion molecule-1; IL-1β: interleukin-1β; IL-6: interleukin-6; IL-8: interleukin-8; MCP-1: monocyte chemoattractant protein 1; p21: cyclin-dependent kinase inhibitor 1; PAI-1: plasminogen activator inhibitor 1; SASP: senescence-associated secretory phenotype; shRNA: small hairpin ribonucleic acid; SnC: senescent cells; SCR: scramble sequence; TNF-α: tumor necrosis factor alpha.