Branzan, D. | bioRxiv Science

bioRxiv2026

Deep Visual Proteomics links vascular smooth muscle cell phenotypes to atherosclerotic plaque stability

Vascular smooth muscle cells (VSMCs) drive atherosclerosis through phenotypic switching, yet their spatial organization and protein signatures within plaques remain poorly characterized. Here, we applied Deep Visual Proteomics (DVP) to dissect more than 500 VSMC neighborhoods across 24 human carotid plaques and profile VSMC plasticity in disease. To functionally interpret these tissue proteomes, we built a reference atlas of primary VSMCs driven toward five phenotypes by TGF-{beta}, PDGF-BB, osteogenic stimuli, IL-1{beta}, or cholesterol, quantifying over 10,000 proteins. We integrated tissue and reference proteomes with a deep-learning framework that assigns functional phenotypes to each neighborhood. This revealed spatially distinct phenotype distributions and a shift toward dedifferentiated states in unstable plaques. Knockdown of four candidates (TNC, TNFAIP2, AEBP1, PLK1) validated operational roles during phenotypic switching. Our approach functionally annotates spatial proteomes and links VSMC plasticity to plaque instability in carotid artery disease.

systems biology↗

bioRxiv2025

Single cell spatial transcriptomics integration deciphers the morphological heterogeneity of atherosclerotic carotid arteries

The process of arterial atherosclerosis is characterised by accumulation of lipids and fibrous material with accompanying inflammation. As plaques progress, they restrict blood flow and cause rupture, which results in life threatening organ ischemia and dysfunction. Although extensively studied, a clear understanding of plaque heterogeneity and mechanisms that trigger their destabilization remains elusive. Our study reveals the molecular microarchitecture of human carotid artery plaques, using bulk and single-cell RNA sequencing combined with single cell spatial transcriptomics, for which we present optimized cell segmentation algorithms. We identified distinct plaque morphologies linked to different cell type compositions, impacting early and advanced lesion formation, as well as destabilization. Spatial transcriptomics enabled us further to determine an inflammatory smooth muscle cell subtype, localize regions of neovascularization, and assign hotspots for macrophage activity within distinct cellular neighbourhoods across lesions. For different macrophage substates, we propose gradual and locally contained transdifferentiation of subluminal inflammatory HMOX1+ macrophages into a lipid-handling TREM2+ phenotype within border zones of the fibrous cap and necrotic core. Our findings provide insight into the complex heterogeneity of human atherosclerosis by unravelling location and proximity of different mural and immune cell substates involved in plaque progression and vulnerability.

cell biology↗