Single-cell transcriptomic analysis of Smad3-deficent mice

To analyze both early and late events associated with Smad3-inactivation, and to identify how specific smooth muscle cell (SMC) phenotypes may confer increased susceptibility to disease in the aortic root, we performed single-cell transcriptomic analysis on aortic cells from control (Smad3+/+; Myh11-CreER; + or – EGFP-L10a mice are refered to as Smad3+/+) and Smad3-deficient (Smad3lox/lox; Myh11-CreER; + or - EGFP-L10a are referred to as Smad3SmKO) mice at 10- and 18-weeks post-deletion, when aortic dilation is undetectable and moderate, respectively. Analysis of SMC-specific transcriptional changes show that, in addition to the expected decrease in TGF-ß -induced expression of extracellular matrix components, Smad3-inactivation resulted in a broad reduction in the expression of components and modulators of focal adhesions, including that of several integrins, anchoring proteins, adaptors and modulators. Overall design: Examination of the aortic transcriptome of mice with postnatal, smooth-muscle specific deletion of Smad3 at two different timeponts, 10- and 18-weeks post-deletion when dilation is undetectable and moderate, respectively.