CCN2 regulates smooth muscle cell trans-differentiation and lipid accumulation in atherosclerosis

Accruing evidence illustrates an emerging paradigm of dynamic vascular smooth muscle cell (SMC) trans-differentiation during atherosclerosis progression. However, the molecular regulators that govern SMC phenotype diversification remain poorly defined. This study aims to elucidate the functional role and underlying mechanisms of cellular communication network factor 2 (CCN2), a matricellular protein, in regulating SMC plasticity in the context of atherosclerosis. Overall design: CCN2-floxed mice were crossed with Myh11-Cre-ERT2 transgenic mice to generate male CCN2-floxed mice harboring SMC-specific Cre (CCN2fl/fl-Myh11-Cre-ERT2). Smooth muscle cell (SMC)-specific deletion of CCN2 was achieved by intraperitoneal (IP) injection of five consecutive doses of tamoxifen to 6-8 weeks old male CCN2fl/fl-Myh11-Cre-ERT2 mice. Age-matched male CCN2-floxed mice without Cre expression subjected to the same tamoxifen regimen were used as controls. After one-week washout period, SMC-specific CCN2-knockout mice, henceforth CCN2SMC? mice and CCN2-floxed control mice, henceforth CCN2fl/fl mice were used for the modeling of atherosclerosis (injected once via tail vein with AAV-PCSK9 (rAAV8/D377Y-mPCSK9,1 × 1011 VG) before being fed for 5 months with high fat diet). Then the aorta of mice were harvested for single cell isolation and sent for Sc-RNA-seq.