👤 Kenneth Caidahl

An abnormal accumulation of immune cells and inflammation has been described in ascending aortic aneurysm, but the factor driving disease initiation remains elusive. Interestingly, ascending aortic dilatation often occurs alongside aortic regurgitation but rarely with aortic stenosis. We sought to investigate ascending aortic aneurysm initiation by assessing the relation between aortic regurgitation and vascular activation and inflammation. In this prospective cohort study, patients with tricuspid aortic valves undergoing elective open-heart surgery were included. Aortic specimens from organ donors were obtained through the University of Miami Tissue Bank. Spatial transcriptomics measured gene expression in nondilated aortic endothelium, intima, and subintima. Immunohistochemistry determined protein expression. Aortic dimensions were recorded preoperatively and 10 years after surgery using echocardiography. Aortic gene expression affected by physiological blood flow was previously measured in Wistar rats. We show a mesenchymal activation of endothelial cells, possibly mediated by bidirectional flow, in the nondilated ascending aorta of patients with aortic regurgitation, accompanied by intimal infiltration, retention, and oxidation of apoB-containing lipoproteins. We further observed intimal upregulation of genes coding for core proteins of lipoprotein-binding proteoglycans and the Our results highlight a distinct pathological role of aortic regurgitation in ascending aortic aneurysm formation by promoting mesenchymal activation of endothelial cells and lipoprotein-related immune cell infiltration and inflammation in patients with tricuspid aortic valves. We also provide novel insights into the long-term impact of surgical aortic valve replacement on ascending aortic growth and suggest a diagnostic or therapeutic target in oxidized low-density lipoprotein cholesterol. Show less

Habitual physical activity (PA) affects metabolism and homeostasis in various tissues and organs. However, detailed knowledge of associations between PA and cardiovascular disease (CVD) risk markers is limited. We sought to identify associations between accelerometer-assessed PA classes and 183 proteomic and 154 metabolomic CVD-related biomarkers. We utilized cross-sectional data from the main SCAPIS cohort (n = 4647, median age: 57.5 yrs, 50.5% female) as a discovery sample and the SCAPIS pilot cohort (n = 910, median age: 57.5 yrs, 50.3% female) as a validation sample. PA was assessed via hip-worn accelerometers, while plasma concentrations of proteomic biomarkers were measured using Olink CVD II and III panels. Metabolomic markers were assessed using the Nightingale NMR platform. We evaluated associations between four PA classes (moderate-to-vigorous PA [MVPA], low-intensity PA [LIPA], sedentary [SED], and prolonged SED [prolSED]) and biomarkers, controlling for potential confounders and applying a false discovery rate of 5% using multiple linear regressions. A total of eighty-five metabolomic markers and forty-three proteomic markers were validated and found to be significantly associated with one or more PA classes. LIPA and SED markers demonstrated significant mirroring or opposing relations to biomarkers, while prolSED mainly shared relations with SED. Notably, HDL species were predominantly negatively associated with SED, whereas LDL species were positively associated with SED and negatively associated with MVPA. Among the proteomic markers, eighteen were uniquely associated with MVPA (among those Interleukin - 6 [IL6] and Growth/differentiation factor 15 [GDF15] both negatively related), seven with SED (among those Metalloproteinase inhibitor 4 [TIMP4] and Tumor necrosis factor receptor 2 [TNFR2], both positively related), and eight were related to both SED/prolSED (among those Lipoprotein lipase [LPL] negatively related to SED and leptin [LEP] positively related to SED) and MVPA (with LPL positively related to MVPA and LEP negatively related to MVPA). Our findings suggest the existence of specific associations between PA classes and metabolomic and cardiovascular protein biomarkers in a middle-aged population. Beyond validation of previous results, we identified new associations. This multitude of connections between PA and CVD-related markers may help elucidate the previously observed relationship between PA and CVD. The identified cross-sectional associations could inform the design of future experimental studies, serving as important outcome measures. Show less

Proprotein convertases (PCSKs) process matrix metalloproteases and cytokines, but their function in the vasculature is largely unknown. Previously, we demonstrated upregulation of PCSK6 in atherosclerotic plaques from symptomatic patients, localization to smooth muscle cells (SMCs) in the fibrous cap and positive correlations with inflammation, extracellular matrix remodeling and cytokines. Here, we hypothesize that PCSK6 could be involved in flow-mediated vascular remodeling and aim to evaluate its role in the physiology of this process using knockout mice. Pcsk6 Show less