miR‐9 promotes canine endothelial‐like cell migration by targeting COL15A1.

Background: Endothelial cell migration is the initial stage of angiogenesis. In previous studies, miR‐9 has been found to regulate angiogenesis and cell migration in human medicine. Objectives: This study aimed to reveal the regulatory effect of miR‐9 on canine endothelial cell migration. Methods: Embryonic canine ventricle myocardium tissues were collected and induced to differentiate into endothelial‐like cells (ELCs). A transwell and invasion assay were used to evaluate the impact of miR‐9 on the migration capacity of ELCs, after which a luciferase reporter assay, western blotting, RNA sequencing and reverse transcription‐polymerase chain reaction were conducted to explore the regulatory mechanism. Results: Our results showed that we successfully induced the primary cells derived from canine cardiac embryo tissues into ELCs. MiR‐9 also promoted the migration and invasion of canine ELCs, and inhibited the expression of collagen XV, an angiogenic inhibitor, at the translational level by targeting the 3′ untranslated region of COL15A1 gene. Furthermore, RNA sequencing showed that overexpression of miR‐9 impacted several signalling pathways and eight genes involved in angiogenesis and cell migration in canine ELCs. Conclusions: These findings suggest that miR‐9 enhances the migration of canine ELCs and may serve as a potential diagnostic and therapeutic target for canine diseases involved in endothelial cells migration and angiogenesis, but more further studies are needed. [ABSTRACT FROM AUTHOR]