Smooth Muscle Progenitor Cells: Friend or Foe in Vascular Disease?

The origin of vascular smooth muscle cells that accumulate in the neointima in vascular diseases such as transplant arteriosclerosis, atherosclerosis and restenosis remains subject to much debate. Smooth muscle cells are a highly heterogeneous cell population with different characteristics and markers, and distinct phenotypes in physiological and pathological conditions. Several studies have reported a role for bone marrow-derived progenitor cells in vascular maintenance and repair. Moreover, bone marrow-derived smooth muscle progenitor cells have been detected in human atherosclerotic tissue as well as in in vivo mouse models of vascular disease. However, it is not clear whether smooth muscle progenitor cells can be regarded as a ‘friend’ or ‘foe’ in neointima formation. In this review we will discuss the heterogeneity of smooth muscle cells, the role of smooth muscle progenitor cells in vascular disease, potential mechanisms that could regulate smooth muscle progenitor cell contribution and the implications this may have on designing novel therapeutic tools to prevent development and progression of vascular disease

Exploring the causal inference of shear stress associated DNA methylation in carotid plaque on cardiovascular risk

BACKGROUND AND AIMS: Atherosclerosis is a lipid-driven inflammatory disease presumably initiated by endothelial activation. Low vascular shear stress is known for its ability to activate endothelial cells. Differential DNA methylation (DNAm) is a relatively unexplored player in atherosclerotic disease development and endothelial dysfunction. Previous studies showed that the expression of 11 genes was associated with differential DNAm due to low shear stress in murine endothelial cells. We hypothesized a causal relationship between DNAm of shear stress associated genes in human carotid plaque and increased risk of cardiovascular disease. METHODS: Using Mendelian randomisation (MR) analysis, we explored the potential causal role of DNAm of shear stress associated genes on cardiovascular disease risk. We used data from the Athero-Expression Biobank Study for the discovery of methylation quantitative trait loci (mQTLs) in 442 advanced carotid plaques. Next, we performed MR analysis using these mQTLs and publicly available GWAS summary statistics of coronary artery disease (CAD) and ischemic stroke (IS). RESULTS: We discovered 9 mQTLs in plaque in the promoters of shear stress associated genes. We found no significant effect of shear stress gene promoter methylation and increased risk of CAD and IS. CONCLUSIONS: Differential methylation of shear stress associated genes in advanced atherosclerotic plaques in unlikely to increase cardiovascular risk in human

Characterization of plaque components with intravascular ultrasound elastography in human femoral and coronary arteries in vitro

BACKGROUND: The composition of plaque is a major determinant of coronary-related clinical syndromes. Intravascular ultrasound (IVUS) elastography has proven to be a technique capable of reflecting the mechanical properties of phantom material and the femoral arterial wall. The aim of this study was to investigate the capability of intravascular elastography to characterize different plaque components. METHODS AND RESULTS: Diseased human femoral (n=9) and coronary (n=4) arteries were studied in vitro. At each location (n=45), 2 IVUS images were acquired at different intraluminal pressures (80 and 100 mm Hg). With the use of cross-correlation analysis on the high-frequency (radiofrequency) ultrasound signal, the local strain in the tissue was determined. The strain was color-coded and plotted as an additional image to the IVUS echogram. The visualized segments were stained on the presence of collagen, smooth muscle cells, and macrophages. Matching of elastographic data and histology were performed with the use of the IVUS echogram. The cross sections were segmented in regions (n=125) that were based on the strain value on the elastogram. The dominant plaque types in these regions (fibrous, fibro-fatty, or fatty) were obtained from histology and correlated with the average strain and echo intensity. The strain for the 3 plaque types as determined by histology differed significantly (P=0.0002). This difference was mainly evident between fibrous and fatty tissue (P=0.0004). The plaque types did not reveal echo-intensity differences in the IVUS echogram (P=0.882). CONCLUSIONS: Different strain values are found between fibrous, fibro-fatty, and fatty plaque components, indicating the potential of intravascular elastography to distinguish different plaque morphologies

Sex-dependent gene co-expression in the human body

Many pathophysiological mechanisms in human health and disease are dependent on sex. Systems biology approaches are successfully used to decipher human disease etiology, yet the effect of sex on gene network biology is mostly unknown. To address this, we used RNA-sequencing data of over 700 individuals spanning 24 tissues from the Genotype-Tissue Expression project to generate a whole-body gene co-expression map and quantified the sex differences per tissue. We found that of the 13,787 genes analyzed in 24 tissues, 29.5% of the gene co-expression is influenced by sex. For example, skeletal muscle was predominantly enriched with genes co-expressed stronger in males, whereas thyroid primarily contained genes co-expressed stronger in females. This was accompanied by consistent sex differences in pathway enrichment, including hypoxia, epithelial-to-mesenchymal transition, and inflammation over the human body. Furthermore, multi-organ analyses revealed consistent sex-dependent gene co-expression over numerous tissues which was accompanied by enrichment of transcription factor binding motifs in the promoters of these genes. Finally, we show that many sex-biased genes are associated with sex-biased diseases, such as autoimmunity and cancer, and more often the target of FDA-approved drugs than non-sexbiased genes. Our study suggests that sex affects biological gene networks by differences in gene co-expression and that attention to the effect of sex on biological responses to medical drugs is warranted

Організаційно-економічні передумови та особливості формування сфери фінансових послуг в економічній системі

Glucocorticoids (GCs) are widely used anti-inflammatory drugs well known to cause many adverse effects. Still, there is a dearth of data on the long-term cardiovascular effects of GCs in patients with established cardiovascular disease and the effect on atherosclerotic plaque composition. A total of 1894 patients who underwent carotid endarterectomy (CEA), of whom 40 patients received systemic GCs, were included in the Athero-Express Biobank. Atherosclerotic plaque samples and peripheral blood samples were obtained during CEA. Cardiovascular events during 3 years of follow-up were investigated using Cox regression modeling to adjust for possible confounding. Atherosclerotic plaque composition was examined using immunohistochemical staining. Use of GCs at inclusion was associated with markedly increased incidences of ischemic stroke (15.2% vs. 5.9%), composite events (48.5% vs. 26.9%), and cardiovascular death (21.2% vs. 5.7%), as well as an increased risk of cardiovascular death (hazards ratio 2.7, 95% confidence interval, 1.1-6.7) and all-cause death (hazards ratio 2.3, 95% confidence interval, 1.1-4.8) after 2.6 years of follow-up. None of the histological features of atherosclerotic plaques were significantly different in patients using GCs. After CEA, the use of systemic GCs is independently associated with an increased incidence of cardiovascular events and an increased risk of cardiovascular and all-cause death, but not atherosclerotic plaque compositio