👤 Winfried Goettsch

Lower-extremity arterial disease (LEAD) is a manifestation of atherosclerotic cardiovascular disease, affecting 230 million people worldwide with increasing prevalence. Medial arterial calcification (MAC) is common in LEAD patients and contributes to disease-related mortality. However, therapeutic strategies targeting femoral MAC are lacking, and its underlying mechanisms remain unclear. This study aimed to identify molecular drivers of femoral MAC in LEAD. Calcium deposits and pro-calcifying markers were analyzed in human patient samples using von Kossa staining, immunofluorescence, and gene expression analysis. Femorals showed significantly more calcification and pro-calcifying gene expression than carotids. Given MAC abundance in LEAD, we assessed medial calcification in Apoe-/- mice fed a WD for 4/21 weeks. Digital PCR revealed upregulation of Ddr1 and Bmp2 in femoral versus carotid arteries after 21 weeks of WD. DDR1 expression positively correlated with calcification in human femoral samples. In vitro experiments with mouse femoral vs. carotid vascular smooth muscle cells (VSMCs) confirmed a significantly higher prevalence of calcifying proteins (DDR1, BMP2, and RUNX2) in femoral VSMCs. Additionally, calcification analyses in murine and human VSMCs showed that DDR1 inhibition reduced, while DDR1 activation increased, calcium deposition. Transcriptomic analysis revealed elevated NF-κB expression in human femoral arteries, matching data in femoral VSMCs. DDR1 stimulation activated NF-κB, and its inhibition blocked DDR1-induced calcification. This study identifies DDR1 as a key driver of calcification in LEAD, operating through NF-κB activation and the expression of calcifying proteins. Targeting DDR1 may offer a novel therapeutic approach to prevent MAC in LEAD. Show less

Arteries and veins show marked differences in their anatomy, physiology and genetic expression pattern. In this study, we analyzed impact of overexpression or downregulation of arterial marker gene Hey2 and venous marker gene COUP-TFII in human venous and arterial endothelial cells on genes involved in arteriovenous differentiation. Lentiviral overexpression of venous marker gene COUP-TFII in arterial endothelial cells led to downregulation of NICD4, arterial marker gene Hey2 and EphrinB2. Downregulation of Hey2 could be mediated by direct binding of COUP-TFII to Hey2 promoter as shown by ChIP, EMSA and promoter analysis. Downregulation of Hey2 by shRNA causes downregulation of EphrinB2 expression. Overexpression of arterial marker Hey2 in venous endothelial cells did not change expression pattern of COUP-TFII. Downregulation of venous marker gene COUP-TFII in venous endothelial cells resulted in upregulation of VEGF-A, Dll4 and EphrinB2 expression. Our data support an important role of Hey2 and COUP-TFII in arteriovenous differentiation of human endothelial cells. Show less