Identification and characterization of a novel porcine endothelial cell-specific Tie1 promoter

Background The use of a transgenic pig for xenotransplantation and as a cardiovascular disease model has caught much attention in the past decades. The vascular endothelial cell is the primary modification target for the application of genetically modified pigs in this field. However, the powerful porcine endothelial cell‐specific promoter is still so rare that the mouse and human promoters are commonly used. In the study, the porcine Tie1 (sTie1) promoter was identified and characterized as a potential endothelial cell‐specific promoter to generate a cardiovascular disease model. Methods Tie1 promoters with different lengths of 5′‐regulatory regions were cloned, and major putative DNA‐binding motifs were mutated by site‐directed mutagenesis. All fragments were ligated into the luciferase reporter system and were transiently transfected into endothelial cells to identify luciferase activity using a dual luciferase reporter assay. Results The luciferase activities of sTie1 promoters with different lengths of the 5′‐regulatory region were tested. Results showed that the luciferase activity of the 1234‐bp sTie1 fragment was the strongest compared with that of others (P