Inflammatory macrophages drive smooth muscle dedifferentiation via YAP signaling in murine deep vein thrombosis
Discuss this preprint
Start a discussion What are Sciety discussions?Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
Background
Deep vein thrombosis (DVT) is a common clinical problem characterized by the formation of blood clots in deep veins. The contribution of venous smooth muscle cells (SMCs) to the onset of DVT, particularly the mechanisms driving their phenotypic changes, remains poorly understood.
Methods
We employed a murine stasis model of DVT via inferior vena cava (IVC) ligation in both male and female mice. Single-cell RNA sequencing (scRNA-seq) was used to analyze the cellular and transcriptomic landscape of the vein wall 24 hours post-ligation. To investigate cellular crosstalk, we utilized an in vitro system where primary mouse aortic SMCs were treated with conditioned media from inflammatory (M1-like) bone marrow-derived macrophages (BMDMs). The effects on SMC phenotype and signaling were assessed using bulk RNA-seq, Western blotting, qRT-PCR, and functional assays.
Results
scRNA-seq analysis revealed that DVT induction promotes a rapid inflammatory response characterized by neutrophil influx and a shift in SMCs from a contractile to a synthetic phenotype in both sexes. Infiltrating myeloid cells were identified as a primary source of signaling to SMCs. In vitro, conditioned media from M1-like macrophages was sufficient to suppress SMC contractile gene expression and function. Mechanistically, this effect was linked to the inhibition of the Hippo pathway effector YAP, evidenced by increased YAP phosphorylation (S127/S397) and a subsequent reduction of total YAP protein in SMCs. We identified macrophage-derived IL-1β as a key ligand that mimics these effects. Importantly, pharmacological activation of YAP rescued contractile gene expression in SMCs exposed to the inflammatory macrophage secretome.
Conclusions
Our findings demonstrate that SMC dedifferentiation occurs early in DVT, driven by inflammatory macrophage-mediated suppression of YAP signaling. This study uncovers a critical macrophage-SMC crosstalk mechanism in early DVT pathogenesis and highlights YAP as a potential therapeutic target to preserve vein wall integrity and prevent long-term complications.
