Genomic changes in porcine regenerated coronary endothelial cells after angioplasty

Abstract

The current study was designed to define genetic changes occurring in regenerated endothelial cells which could explain the phenotypic alterations that underlie their dysfunction and ultimately lead to vascular damage. Regeneration of endothelium was initiated in the pig by percutaneous transluminal coronary angioplasty of the left anterior descending artery. After 28 days, the endothelial cells of the left circumflex (native cells) and the left anterior descending (regenerated cells) arteries were isolated and cultured. The differential mRNA expression at passage zero was evaluated with the GeneChip® porcine genome array (Affimetrix Inc). The production of cyclic GMP under basal conditions and upon stimulation (bradykinin, A23187) was measured both in native and regenerated endothelial cells at passage 1. Microarray analysis revealed an up-regulation of senescence-associated gene, beta-galactosidase, putative NFκB activating protein and other apoptosis-related components. Down-regulation of genes includes telomere-associated protein RIF1 homolog. Both VWF-, CD 31-positive and CD 34-low endothelial cells were observed at passage 1 with immunofluorescent staining. The basal cyclic GMP production was reduced significantly in regenerated cells compared to that in native cells without significant changes in responses to bradykinin or A23187. Thus, genomic analysis revealed differential gene expression of senescence- and apoptosis-associated genes in regenerated porcine coronary endothelial cells indicating a previously unidentified linkage between endothelial regeneration and initiation of endothelial dysfunction.