Shear stress is uncoupled from atheroprotective KLK10 in atherosclerotic plaques

Physiological shear stress promotes vascular homeostasis by inducing protective molecules in endothelial cells (EC). However, physiological shear stress has been linked to atherosclerosis progression in some individuals with heightened cardiovascular risk. To address this apparent paradox, we hypothesized that diseased arteries may exhibit reduced responsiveness to the protective effects of physiological shear stress. Consequently, we compared the transcriptome of EC exposed to physiological shear stress in healthy arteries versus atherosclerotic conditions. Employing 3D light sheet imaging and computational fluid dynamics, we identified NOS3 as a marker of physiological shear stress in both healthy and atherosclerotic murine arteries. Single-cell RNA sequencing was performed on EC from healthy (C57BL/6) mice, mildly diseased (Apoe−/− normal diet) mice, and highly diseased (Apoe−/− high fat diet) mice. The transcriptomes of Nos3high cells (exposed to physiological shear stress) were compared among the groups. Nos3high EC were associated with several markers of physiological shear stress in healthy arteries. Clustering of Nos3high EC revealed 8 different EC subsets that varied in proportion between healthy and diseased arteries. Cluster-specific nested functional enrichment of gene ontology terms revealed that Nos3high EC in diseased arteries were enriched for inflammatory and apoptotic gene expression. These alterations were accompanied by changes in several mechanoreceptors, including the atheroprotective factor KLK10, which was enriched in Nos3high EC in healthy arteries but markedly reduced in severely diseased arteries. Physiological shear stress is uncoupled from atheroprotective KLK10 within atherosclerotic plaques. This sheds light on the complex interplay between shear stress, endothelial function, and the progression of atherosclerosis in individuals at risk of cardiovascular complications. [Display omitted] •We combined optical clearing, immunostaining, light sheet imaging, and fluid dynamics to analyze proteins in plaques.•Our method shows that NOS3 can identify endothelial cells under high shear stress in atherosclerotic and healthy arteries.•scRNAseq and staining reveal severe atherosclerosis causes loss of KLK10 in endothelium exposed to high shear stress.•These findings may explain the link between high shear stress and disease progression seen in certain patient groups.