Endothelial tenascin signaling preserves VSMCs contractile phenotype in the human arterial wall in type II diabetes mellitus

Abstract Background Phenotypic switching of vascular smooth muscle cells (VSMCs) is a hallmark of coronary artery disease (CAD). How type 2 diabetes mellitus (T2DM), a major risk factor for cardiovascular complications, reshapes these VSMCs states remains poorly defined. Methods Single-cell RNA sequencing (scRNA-seq), spatial transcriptomics, high-dimensional weighted gene coexpression network analysis (hdWGCNA), and cell‒cell interaction analysis were used to profile human arterial tissue from CAD patients with or without T2DM who underwent coronary artery bypass graft surgery. Spot-level cell-type proportions were estimated by SPOTlight using the matched scRNA-seq reference. Reverse transcription quantitative PCR (RT-qPCR), western-blotting, and immunofluorescence staining were used to validate results from the above analysis. Wound healing assay, transwell assay, and collagen gel contraction assay were used to detect VSMCs cellular functions under different treatment. Results A special contractile VSMCs_0 subtype was detected in the aortic tissue of CAD patients with T2DM. Donor-level models analysis showed that the proportion of VSMC_0 was enriched and other subclusters were not significant or reduced. Besides, hdWGCNA indicated that a group of marker genes of VSMC_0 was included in a co-expression gene module which was highly correlated with T2DM. Spatial maps localized VSMC_0 signals to the intima–media interface of the aortic tissue, which was spatially in close proximity to endothelial cells (ECs). Moreover, we identified the tenascin XB (TNXB)/integrin subunit alpha 8 (ITGA8) axis as a potential regulator of the contractile phenotype of VSMCs. Conclusions These findings underscore the potential role of the TNXB/ITGA8 pathway in maintaining vascular homeostasis, thereby providing a novel translational approach to intervene in VSMCs phenotypic modulation in CAD patients with T2DM.