Welcome to the EAS 2021 Interactive Program
The congress will officially run on EEST time zone (Eastern European Summer Time, Helsinki, CET+1)
Introduction (ID 1584)
Dietary polyphenols and arterial stiffness (ID 1303)
The role of smooth muscle cells in plaque stability (ID 1304)
O065 - Single-Cell Analysis Uncovers Osteoblast Factor GDF10 as Mediator of Vascular Smooth Muscle Cell Phenotypic Modulation Associated with Plaque Rupture in Human Carotid Artery Disease (ID 665)
Abstract
Background and Aims
Vascular smooth muscle cells (VSMC) are not terminally differentiated and undergo complex phenotypic changes during atherosclerosis. However, the complex heterogeneity of VSMC and how VSMC de-differentiation affects human carotid artery disease (CAD) risk has not been clearly established. The aim of the present study is to comprehensively characterized the transcriptomic profile of phenotypically modulated VSMC and to identify mediators of VSMC transition to osteogenic like cells with likely detrimental role for atherosclerosis plaque stability.
Methods
Single-cell RNA sequencing of CD45 negative cells derived from Apoe-/- mice on a normal (NCD) or high cholesterol diet (HCD) was performed. To confirm the identified marker mediator of VSMC transition to osteogenic like cells, immunofluorescence staining of aortic roots of VSMC lineage tracing Apoe-/- Myh11-CreERT2, ROSA26 STOP-flox eYFP+/+ mice fed an NCD or HCD and of internal carotid plaque specimens from symptomatic and asymptomatic patients with CAD was used. VSMC osteogenic switch was quantified upon GDF10 and oxLDL stimulation by flow cytometry.
Results
Disease-relevant gene signature of VSMC macrophagic calcific phenotype, VSMC mesenchymal chondrogenic phenotype, VSMC inflammatory and fibro phenotype and VSMC inflammatory phenotype was revealed. The osteoblast factor GDF10 was highly expressed in phenotypically modified VSMC clusters, in parallel GDF10 stimulation in combination with oxLDL triggered VSMC osteogenic switch in vitro. Moreover, higher GDF10 expression in phenotypically modified VSMC in human atherosclerotic plaques was associated with an increased risk of plaque rupture in CAD patients.
Conclusions
Osteoblast factor GDF10 is associated with VSMC transition to osteogenic like cells with likely detrimental role in atherosclerosis plaque stability.
O066 - Macrophages, Smooth Muscle Cells and Nod1 inhibition in advanced stages of Atherosclerosis: a clue to plaque stabilization and atherothrombosis attenuation (ID 11)
Abstract
Background and Aims
Macrophages and Smooth Muscle Cells (SMCs) are well known to have a preeminent role in plaque necrosis and rupture. These events, added to inflammation and thin layers of collagen unchain atherothrombosis, the main cause of Acute Coronary Syndromes (ACs). Pattern recognition receptor Nucleotide-Binding Oligomerization Domain-1 (NOD1) has previously been linked to inflammation and cardiovascular diseases. The aim of this work was to unveil the function of NOD1 in the plaque stabilization phenomena in the late stages of the disease.
Methods
Athero-prone Apoe-/-Nod1-/- against Apoe-/-mice were treated with high fat diet for 16 weeks in order to characterized the advanced lesions in the aortic sinus. Proliferation, apoptosis and foam cell formation were assessed in the atheroma lesions and in primary cell cultures of macrophages and vascular SMCs. In addition, human coronary arteries were employed. Cell procedures, flow cytometry, immunofluorescences, histochemistry techniques, qRT-PCR, western blot and kinetic colorimetric assays were performed.
Results
ORO stained aorta showed a reduction in the atheroma of the double-knockout mice. NOD1 staining in human atherosclerotic coronary arteries was enhanced near lipid deposition areas and NOD1 expression was higher in Macrophages (MAC3 marker) and SMCs (Smooth Muscle α-actin marker) of these plaques. We also demonstrated that NOD1 deletion or inhibition reduced myeloid cells infiltration, macrophage and SMCs apoptosis, fibrous caps and collagen content. Interestingly, Nod1-/-SMCs presented higher proliferation rates.
Conclusions
To conclude, here we determine that both macrophages and SMCs are subjected to NOD1 regulation under advanced atherogenesis condition, triggering plaque vulnerability and thus promoting atherothrombosis and ACS.
O067 - Characterization of novel interactions with plasma membrane NEU1 reveals new biological functions for the Elastin Receptor Complex in vascular diseases (ID 988)
Abstract
Background and Aims
Remodeling of elastin during pathophysiological vascular aging leads to the production of elastin-derived peptides (EDP), also known as elastokines. These peptides trigger biological effects through the elastin receptor complex (ERC). Data from the last decade have brought significant insights on the critical role played by its catalytic subunit, Neuraminidase-1 (NEU1), in the biological effects mediated by EDP in vascular and metabolic diseases.
Methods
We recently developed a proteomic approach dedicated to the purification and identification of membrane NEU1-associated protein complexes in human macrophages and identified several promising candidates (Kawecki et al, CMLS. 2019).
Results
Here, we validated and characterized two novel interactions with NEU1 in human monocytes and endothelial cells involving the β2 integrin and ICAM-1, respectively. We show that binding of EDP to the ERC leads to desialylation of monocyte β2 integrin and endothelial ICAM-1 through membrane NEU1. Importantly, desialylation of either monocyte β2 integrin or endothelial ICAM-1 by EDP is sufficient to potentiate monocyte adhesion to a monolayer of endothelial cells.
Conclusions
These results demonstrate, for the first time, that binding of EDP to the ERC modulates the sialylation levels of monocyte β2 integrin and endothelial ICAM-1 through NEU1, and highlight that EDP and the ERC may be important regulators of circulating monocytes recruitment to inflamed vascular sites through this sialidase. By its ability to interact with and to modulate the sialylation of key membrane glycoproteins through NEU1, new biological functions are anticipated for EDP and the ERC in vascular diseases involving elastic fibers and elastin degradation.
O068 - Telomere damage promotes vascular smooth muscle cell senescence and immune cell recruitment after vessel injury (ID 194)
Abstract
Background and Aims
Background and Aims: Vascular smooth muscle cells (VSMCs) accumulate in injury-induced neointimal lesions and atherosclerotic plaques in an oligoclonal fashion, yet plaque VSMCs show reduced proliferation and cell senescence. DNA damage leads to VSMC senescence and inflammation and VSMC senescence promotes atherosclerosis; however, the exact mechanism by which VSMC senescence promotes lesion formation is not known. Here, we investigated telomere damage-induced VSMC senescence, the contribution of senescence-induced inflammation and the mechanisms involved, the consequences of VSMC senescence in vivo after injury, and whether it promotes clonality.
Methods
Methods: Stress-induced premature senescence (SIPS) was induced by doxorubicin (24h treatment+21d recovery). Lentiviruses were used to stably overexpress a dysfunctional TRF2 mutant protein (TRF2T188A) in hVSMCs. SM22αTRF2T188A mice were generated that express human TRF2T188A in VSMCs only, and crossed with Myh11-CreERT2 Rosa26-Confetti multicolour reporter mice to examine cell senescence and clonality in vivo.
Results
Results: Both SIPS and TRF2188A-induced VSMC senescence were characterised by persistent telomere damage, and associated with formation of micronuclei, activation of cGAS-STING cytoplasmic DNA sensing, and induction of multiple pro-inflammatory cytokines. Silencing of cGAS in TRF2T188A hVSMCs partially inhibited NFκB-dependent cytokine expression. In vivo, VSMC-specific TRF2T188A expression in a multicolour VSMC-tracking model demonstrated no change in VSMC clonal patches after injury, but increased neointima formation, outward remodelling, and immune/inflammatory cell infiltration or retention.
Conclusions
Conclusion: Persistent telomere damage promotes VSMC senescence and inflammation and exacerbates neointima formation after injury. Our data suggest that persistent telomere damage-induced VSMC senescence plays a major role in driving inflammation through immune cell recruitment in vascular disease.