Gene expression from pericytes and endothelial cells

Aims: Vascular wall resident stem cells (SCs) hold great promise for cardiovascular regenerative therapy. This study evaluated the impact of oxidative stress on the viability and functionality of saphenous vein'derived pericytes (SVPs), SVPs'deriv ed cells and terminally differentiated vascular cells. We also investigated the molecular mechanisms underlying the SVP resistance to oxidative stress. Results: SVPs exhibit a significantly higher resistance to oxidative stress resulting in reduced apoptosis upon exposure to hydrogen peroxide in comparison to endothelial cells (ECs). This was attributed to upregulation of genes encoding for anti'oxidant enzymes, especially superoxide dismutases (SODs) and catalase. Pharmacological inhibition of SODs increased ROS levels in SVPs and impaired their survival. Furthermore, we confirm that, when exposed to differentiation stimuli, SVPs are able to generate mesodermic lineages. Interestingly, differentiation of SVPs resulted in SOD down'regulation and increased apoptosis upon exposure to hydrogen peroxide. Oxidative stress caused an incremental increase on SVPs migration, whilst being inhibitory for the ECs. Additionally, oxidative stress did not impair SVPs capacity to promote angiogenesis in vitro. Innovations: This study for the first time demonstrates that SCs resident in veins of cardiovascular patients are endowed with enhanced detoxifier and antioxidant system. Conclusions: SVPs expanded from vein remnants of coronary artery bypass graft surgery express antioxidant defense mechanisms which allow them resist to high levels of ROS. These properties highlight the potential of SVPs in cardiovascular regenerative medicine. 2 groups 3 replicates