A Cell Atlas of Thoracic Aortic Perivascular Adipose Tissue: a focus on mechanotransducers.

Perivascular adipose tissue (PVAT) is increasingly recognized for its function in mechanotransduction. However, major gaps remain in our understanding of the cells present in PVAT, as well as how different cells contribute to mechanotransduction. We hypothesized that snRNA seq would reveal expression of mechanotransducers, and test one (PIEZO1) to illustrate the expression and functional agreement between single-nuclei RNA sequencing (snRNAseq) and physiological measurements. To contrast two brown tissues, subscapular brown adipose tissue (BAT) was also examined. We used snRNAseq of the thoracic aorta PVAT (taPVAT) and BAT from male Dahl SS rats to investigate cell-specific expression mechanotransducers. Localization and function of the mechanostransducer PIEZO1 was further examined using immunohistochemistry (IHC) and RNAscope®, as well as pharmacological antagonism. Approximately 30,000 nuclei from taPVAT and BAT each were characterized by snRNAseq, identifying 8 major cell types expected and one unexpected (nuclei with oligodendrocyte marker genes). Cell-specific differential gene expression analysis between taPVAT and BAT identified up to 511 genes (adipocytes) with many (≥20%) being unique to individual cell types. Piezo1 was the most highly, widely expressed mechanotransducer. Presence of PIEZO1 in the PVAT but not the adventitia was confirmed by RNAscope® and IHC in male and female rats. Importantly, antagonism of PIEZO1 by GsMTX4 impaired the PVAT's ability to hold tension. Collectively, the cell compositions of taPVAT and BAT are highly similar, and PIEZO1 is likely a mechanotransducer in taPVAT.