GSE192712
Mechanical Strain Induces Transcriptomic Reprogramming of Saphenous Vein Progenitors
Purpose: Intimal hyperplasia is the leading cause of graft failure in aortocoronary bypass grafts performed using human saphenous vein (SV). The long-term consequences of the altered pulsatile stress on the cells that populate the vein wall remain elusive, in particular onto saphenous vein progenitors (SVPs), adult cell phenotype of the human adventitia that upholds differentiation capacity. In the present study, we performed global transcriptomic profiling of SVPs that underwent in vitro uniaxial cyclic strain, a type of mechanical stimulation that we recently found to be involved in the pathology of the SV. Methods: To investigate the effect of mechanical strain on cultured cells, SVPs were subjected to cyclic strain using the FlexCell Tension Plus FX-5000T system. Cells were subjected to uniaxial cyclic deformation protocol (0-10% deformation, 1 Hz frequency), for 24 and 72 hours, while static controls were provided by seeding an equal amount of cells, under the same atmospheric conditions, but without mechanical stimulation. For RNA-Seq analysis, total RNA was extracted from 5 different donors of SVPs using TRIzol, treated with DNase I, and quantified by using NanoDrop-1000 spectrophotometer before integrity assessment with Agilent 2100 Bioanalyzer (RNA Integrity Number values >8). Results: Results showed a consistent stretch-dependent gene regulation in cyclically strained SVPs vs. controls, especially at 72hrs. We also observed a robust mechanically related overexpression of Adhesion Molecule with Ig Like Domain 2 (AMIGO2), a cell surface type I transmembrane protein involved in cell adhesion. The overexpression of AMIGO2 in stretched SVPs was associated with the activation of the transforming growth factor ß pathway and modulation of cell signalling, cell-cell, and cell-matrix interactions. Conclusions: These results show that mechanical stress promotes SVPs' molecular phenotypic switching and increases their responsiveness to extracellular environment alterations, thus prompting the targeting of new molecular effectors to improve the outcome of bypass graft procedure. Overall design: mRNA profiles of human saphenous vein progenitors that underwent in vitro uniaxial cyclic strain for 24 and 72 hours