Characterization of novel endothelial-specific and smooth-muscle specific Poldip2 knockout mice

Poldip2 is a multifunctional protein whose roles are only partially understood. The previous Poldip2 knockout mouse generated by the gene trap model suffers from two limitations: perinatal lethality in homozygotes and constitutive Poldip2 inactivation. To overcome these limitations, we developed a new conditional floxed Poldip2 mouse. Here, we correctly targeted floxed Poldip2 mice to produce an endothelial-specific by crossing it with CDH5 ERT2 Cre mouse. Additionally, we also produced smooth-muscle specific Poldip2 knockout mice by crossing the flox'ed Poldip2 mice with SM22A-Cre mice. The Poldip2_EC-/- and Poldip2_SMC-/-mice were viable and showed remarkably reduced Poldip2 expression. To characterize the effect of Poldip2 ablation in the ECs and in the SMCs, we performed a RNA-seq study using the carotid arteries of these mice. The carotid arteries were harvested from the Poldip2 knockout mice (n=4) as well as from the littermate controls (n=4). The lumen of these arteries were quickly flushed with Qiazol to extract the endothelial-enriched RNAs. Also, RNAs were extracted from the leftover arteries (containing the media and adventitia, consisting of smooth muscle cells and other adventiatial cells). These RNAs were subjected to RNAseq to determine the effect of Poldip2 knockdown in endothelium and in the vascular smooth muscle fraction of the carotid arteries.