Publication
Title
Spermidine reduces lipid accumulation and necrotic core formation in atherosclerotic plaques via induction of autophagy
Author
Abstract
Background and aims Spermidine is an endogenous biological polyamine that exhibits broad longevity-extending activities via the induction of autophagy. Because basal autophagy is atheroprotective during early atherosclerosis but dysfunctional in advanced plaques, the aim of the present study was to assess the potential beneficial effects of autophagy induction by spermidine on atherosclerotic plaque progression and composition. Methods Apolipoprotein E-deficient (ApoE−/−) mice were fed a Western-type diet for 20 weeks with or without 5 mM spermidine in the drinking water. Results (Immuno-)histochemical analysis of plaques in the aortic root, proximal ascending aorta and brachiocephalic artery showed that spermidine changed neither the size of the plaque nor its cellular composition. However, spermidine treatment significantly reduced necrotic core formation (6.6 ± 0.5% vs. 3.7 ± 0.5% in aortic root, p = 0.0008) and lipid accumulation inside the plaque (27 ± 3% vs. 17 ± 1% oil red O positivity in thoracic aorta, p = 0.017). In vitro experiments showed that macrophages, unlike vascular smooth muscle cells (VSMCs), were relatively insensitive to autophagy induction by spermidine. Along these lines, spermidine triggered cholesterol efflux in autophagy-competent VSMCs (5.7 ± 1.2% vs. 8.7 ± 0.2%, p = 0.0118), but not in autophagy-deficient Atg7F/FSM22α-Cre+ VSMCs or macrophages. Analogous to the experiments in vitro, spermidine affected neither necrosis nor lipid load in plaques of Atg7F/FSM22α-Cre+ApoE−/− mice. Conclusions Spermidine inhibits lipid accumulation and necrotic core formation through stimulation of cholesterol efflux, albeit without changing plaque size or cellular composition. These effects, which are driven by autophagy in VSMCs, support the general idea that autophagy induction is potentially useful to prevent vascular disease.
Language
English
Source (journal)
Atherosclerosis. - Amsterdam
Publication
Amsterdam : 2016
ISSN
0021-9150
Volume/pages
251(2016), p. 319-327
ISI
000381262100046
Full text (Publisher's DOI)
Full text (open access)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 26.08.2016
Last edited 08.08.2017
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