Abstract Thu115: TRPV4 Regulates Aortic Root Stiffening, Cell Heterogeneity, and Transcriptional Dynamics in Atherosclerosis

Atherosclerosis is a major contributor to cardiovascular disease, the leading cause of death in developed countries. Arterial stiffness is a significant risk factor for atherosclerosis. This study explores the role of transient receptor potential vanilloid 4 (TRPV4), a mechanosensitive ion channel, in regulating aortic stiffness, cell heterogeneity, and transcriptional dynamics in atherosclerosis. Herein, we investigated the role of TRPV4 in atherosclerosis using ApoE-/- and ApoE-/-TRPV4-/- mice fed a high-fat diet (HFD) or control chow (n = 10 mice/group). After 12 weeks on HFD, ApoE-/-TRPV4-/- mice exhibited a 4-fold reduction in atherosclerotic plaque formation in the aortic root and arch compared to ApoE-/- mice. There were no significant differences in body weight gain, plasma total cholesterol (1120 ± 200 vs 1089 ± 170 mg/dL) or triglyceride (120 ± 11 vs 116 ± 12 mg/dL) levels between ApoE-/-TRPV4-/- and ApoE-/- mice, suggesting that the observed atheroprotective effect may be linked to the absence of TRPV4-dependent functions in this model. Atomic force microscopy (AFM) analysis revealed a 6-fold increase in aortic root stiffness in ApoE-/- mice on HFD, whereas TRPV4-deficient mice showed lower stiffness. These results suggest TRPV4 contributes to aortic stiffening during atherogenesis. Additionally, AFM analysis of macrophages, a critical cell type in atherosclerosis, showed increased stiffness in wild-type cells compared to TRPV4-/- cells under both unstimulated and oxidized LDL-stimulated conditions. Human aortic root biopsies from atherosclerosis patients showed increased TRPV4, CD68+ macrophages, and alpha-SMA+ myofibroblasts compared to healthy controls, with a strong correlation between TRPV4 expression and tissue stiffness. We used single-nucleus RNA sequencing on aortic root tissues from ApoE-/- and ApoE-/-TRPV4-/- mice, identifying 13 cell clusters and revealing that TRPV4 deficiency drives significant transcriptional reprogramming in macrophages and vascular endothelial cells, highlighting TRPV4's key role in regulating atherosclerosis. Overall, our findings indicate that TRPV4 plays an essential role in promoting matrix stiffening and atherosclerosis by regulating the stiffness of both macrophages and aortic tissues, and modulating cell heterogeneity, and transcriptional reprogramming. Targeting TRPV4-mediated mechanosensing may offer a novel therapeutic approach to atherosclerosis.