Serum from patients with erectile dysfunction inhibits circulating angiogenic cells from healthy men: relationship with cardiovascular risk, endothelial damage and circulating angiogenic modulators

Abstract

Erectile dysfunction (ED) is an early manifestation of arteriosclerosis associated with endothelial damage/dysfunction and to a blunted ability of cultured mononuclear circulating cells (MNCs) to differentiate circulating angiogenic cells (CACs), putatively involved in endothelial damage repair. Here we explored effects of human serum (HS) from patients with ED and cardiovascular risk factors (VRFs) but no clinical atherosclerosis, on cultured MNCs of healthy men to differentiate CACs and to form colonies. Effect of HS on number of CACS and of colony forming units (CFUs) was correlated with circulating markers of endothelial damage and with angiogenic modulators. MNCs from healthy men were cultured in standard conditions or with 20% HS from 35 patients with ED and from 10 healthy men. CACs were identified after 7 days of culture by uptake of acetylated low-density lipoprotein with concomitant binding of Ulex europaeus agglutinin I. CFUs were counted after 5 days of culture. Enzyme-linked immunosorbent assays assessed plasmatic soluble (s) form of E-selectin, Endothelin (ET)-1, tissue type plasminogen activator (tPA), vascular endothelial growth factor (VEGF)₁₆₅ and sVEGF receptor (R)-1. The number of CACs and of CFUs from healthy men was reduced after culturing MNCs with HS compared to standard medium. The inhibitory effect was significantly higher with HS from ED patients with higher or lower VRF exposure compared to healthy men. Inhibition was positively correlated with VRFs exposure, with ED severity, with common carotid artery intima media thickness measured using B-mode ultrasound, and to a lesser extent with plasmatic sE-Selectin, sET-1 and sVEGFR-1. Dysfunction of cells involved in vascular homoeostasis is induced by soluble factors still unknown and already present in a very initial systemic vascular disease in men with ED and VRFs.