AKAP12 Variant 1 Knockout Enhances Vascular Endothelial Cell Motility.

Introduction: Previous work indicates that AKAP12 is expressed in endothelial cells as two variants and may play a role in cell motility. However, the role of each variant in cell motility is unknown; therefore, this study investigated the role of AKAP12 in endothelial cell motility with a specific focus on AKAP12 variants, AKAP12v1 and AKAP12v2.

Methods: AKAP12 expression levels in cultured endothelial cells were determined by Western blotting and immunofluorescence microscopy. AKAP12 knockdown and AKAP12 variant knockout were done using antisense oligonucleotide and siRNA treatment and CRISPR/Cas9 knockout, respectively. The effect of AKAP12 variant knockout was further analyzed by RNA-seq.

Results: AKAP12 expression was cell density-dependent, with the highest expression in subconfluent cultures and lowest in confluent cultures. AKAP12 expression was also elevated in cells at the wound edge of wounded endothelial cell monolayers. Knockdown of both variants inhibited cell migration, but CRISPR/Cas9 knockout of AKAP12v1 enhanced migration. RNA-seq revealed that loss of AKAP12v1 affected genes associated with cell migration and intercellular junctions.

Conclusion: We propose that AKAP12v1 and AKAP12v2 play distinct yet complementary roles in endothelial cell migration and likely work together in controlling the signaling events associated with vascular repair and development.