Atherosclerosis is the main risk factor for cardiovascular disease (CVD), which is the leading cause of mortality worldwide. Atherosclerosis is initiated by endothelium activation and, followed by a cascade of events (accumulation of lipids, fibrous elements, and calcification), triggers the vessel narrowing and activation of inflammatory pathways. The resultant atheroma plaque, along with these processes, results in cardiovascular complications. This review focuses on the different stages of atherosclerosis development, ranging from endothelial dysfunction to plaque rupture. In addition, the post-transcriptional regulation and modulation of atheroma plaque by microRNAs and lncRNAs, the role of microbiota, and the importance of sex as a crucial risk factor in atherosclerosis are covered here in order to provide a global view of the disease.

Vascular smooth muscle cells (VSMCs) are central players in carotid atherosclerosis plaque development. Although the precise mechanisms involved in plaque destabilization are not completely understood, it is known that VSMC proliferation and migration participate in plaque stabilization. In this study, we analyzed expression patterns of genes involved in carotid atherosclerosis development (e.g., transcription factors of regulation of SMC genes) of VSMCs located inside or outside the plaque lesion that may give clues about changes in phenotypic plasticity during atherosclerosis. VSMCs were isolated from 39 carotid plaques extracted from symptomatic and asymptomatic patients by endarterectomy. Specific biomarker expression, related with VSMC phenotype, was analyzed by qPCR, western immunoblot, and confocal microscopy. MYH11, CNN1, SRF, MKL2, and CALD1 were significantly underexpressed in VSMCs from plaques compared with VSMCs from a macroscopically intact (MIT) region, while SPP1, KLF4, MAPLC3B, CD68, and LGALS3 were found significantly upregulated in plaque VSMCs versus MIT VSMCs. The gene expression pattern of arterial VSMCs from a healthy donor treated with 7-ketocholesterol showed high similarity with the expression pattern of carotid plaque VSMCs. Our results indicate that VSMCs isolated from plaque show a typical SMC dedifferentiated phenotype with macrophage-like features compared with VSMCs isolated from a MIT region of the carotid artery. Additionally, MYH11, KLF5, and SPP1 expression patterns were found to be associated with symptomatology of human carotid atherosclerosis.

Cardiovascular disease (CVD), the leading cause of mortality worldwide is primarily caused by atherosclerosis, which is promoted by the accumulation of low-density lipoproteins into the intima of large arteries. Multiple nanoparticles mimicking natural HDL (rHDL) have been designed to remove cholesterol excess in CVD therapy. The goal of this investigation was to assess the cholesterol efflux efficiency of rHDLs with different lipid compositions, mimicking different maturation stages of high-density lipoproteins (HDLs) occurring in vivo. Methods: the cholesterol efflux activity of soybean PC (Soy-PC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), DPPC:Chol:1-palmitoyl-2-hydroxy-sn-glycero-3-phosphocholine (LysoPC) and DPPC:18:2 cholesteryl ester (CE):LysoPC rHDLs was determined in several cell models to investigate the contribution of lipid composition to the effectiveness of cholesterol removal. Results: DPPC rHDLs are the most efficient particles, inducing cholesterol efflux in all cellular models and in all conditions the effect was potentiated when the ABCA1 transporter was upregulated. Conclusions: DPPC rHDLs, which resemble nascent HDL, are the most effective particles in inducing cholesterol efflux due to the higher physical binding affinity of cholesterol to the saturated long-chain-length phospholipids and the favored cholesterol transfer from a highly positively curved bilayer, to an accepting planar bilayer such as DPPC rHDLs. The physicochemical characteristics of rHDLs should be taken into consideration to design more efficient nanoparticles to promote cholesterol efflux.

Carotid artery atherosclerosis is a risk factor to develop cerebrovascular disease. Atheroma plaque can become instable and provoke a cerebrovascular event or else remain stable as asymptomatic type. The exact mechanism involved in plaque destabilization is not known but includes among other events smooth muscle cell (SMC) differentiation. The goal of this study was to perform thorough analysis of gene expression differences in SMCs isolated from carotid symptomatic versus asymptomatic plaques. Comparative transcriptomics analysis of SMCs based on RNAseq technology identified 67 significant differentially expressed genes and 143 significant differentially expressed isoforms in symptomatic SMCs compared with asymptomatic. 37 of top-scoring genes were further validated by digital PCR. Enrichment and network analysis shows that the gene expression pattern of SMCs from stable asymptomatic plaques is suggestive for an osteogenic phenotype, while that of SMCs from unstable symptomatic plaque correlates with a senescence-like phenotype. Osteogenic-like phenotype SMCs may positively affect carotid atheroma plaque through participation in plaque stabilization via bone formation processes. On the other hand, plaques containing senescence-like phenotype SMCs may be more prone to rupture. Our results substantiate an important role of SMCs in carotid atheroma plaque disruption.

Vascular smooth muscle cells (VSMCs) provide vital contractile force within blood vessel walls, yet can also propagate cardiovascular pathologies through proliferative and pro-inflammatory activities. Such phenotypes are driven, in part, by the diverse effects of long non-coding RNAs (lncRNAs) on gene expression. However, lncRNA characterisation in VSMCs in pathological states is hampered by incomplete lncRNA representation in reference annotation. We aimed to improve lncRNA representation in such contexts by assembling non-reference transcripts in RNA sequencing datasets describing VSMCs stimulated in vitro with cytokines, growth factors, or mechanical stress, as well as those isolated from atherosclerotic plaques. All transcripts were then subjected to a rigorous lncRNA prediction pipeline. We substantially improved coverage of lncRNAs responding to pro-mitogenic stimuli, with non-reference lncRNAs contributing 21–32% for each dataset. We also demonstrate non-reference lncRNAs were biased towards enriched expression within VSMCs, and transcription from enhancer sites, suggesting particular relevance to VSMC processes, and the regulation of neighbouring protein-coding genes. Both VSMC-enriched and enhancer-transcribed lncRNAs were large components of lncRNAs responding to pathological stimuli, yet without novel transcript discovery 33–46% of these lncRNAs would remain hidden. Our comprehensive VSMC lncRNA repertoire allows proper prioritisation of candidates for characterisation and exemplifies a strategy to broaden our knowledge of lncRNA across a range of disease states.