FRI0519 Systemic Sclerosis Sera Affect in Vitro Angiogenesis, Wound Healing Capacity and Migration of Dermal Blood Microvascular Endothelial Cells: Therapeutic Implications of Cyclophosphamide

Background Systemic sclerosis (SSc) is a complex connective tissue disease characterized by extensive fibrosis and vascular abnormalities. Dermal capillaries are progressively reduced in number with consequent chronic tissue hypoxia insufficiently compensated by angiogenesis. In SSc, clinical studies reported that cyclophosphamide (CYC) treatment may significantly improve nailfold capillary damage. Moreover, our group has recently shown that the beneficial effects of CYC treatment in SSc may be due in part to the normalization of the endothelial cell-matrix interactions. Objectives In the present study, we evaluated the effects of sera from naive or CYC-treated SSc patients on the in vitro capacity of human adult dermal blood microvascular endothelial cells (B-MVECs) to perform angiogenesis and to migrate and proliferate in response to injury. Methods Dermal B-MVECs were challenged with sera from SSc patients (n=21; n=13 limited SSc (lSSc) and n=8 diffuse SSc (dSSc)), treatment-naive (n=8) or under CYC treatment (n=13), and sera from healthy controls (n=8). Angiogenesis was evaluated after 24 hours of cell seeding on Geltrex (reduced growth factor basement membrane matrix) in endothelial basal medium containing 2% fetal bovine serum and 10% control or SSc serum. The number of branching points was quantified. Wound healing assay was performed on confluent cells grown in 12-well plates and evaluated at 24 hours after wounding. Chemotaxis was assessed by using the Boyden chamber assay. Results Angiogenesis was significantly reduced upon challenge with sera from treatment-naive SSc patients compared with healthy controls (p Conclusions Treatment-naive SSc sera have significant inhibitory effects on angiogenesis, wound healing capacity and chemotaxis of dermal B-MVECs. Moreover, the inhibitory effects of dSSc sera are significantly stronger than those of lSSc sera. Challenge with CYC-treated SSc sera effectively maintained B-MVEC angiogenesis on Geltrex at levels comparable to those of healthy control sera. Conversely, it was not able to specifically restore B-MVEC wound healing capacity and chemotaxis. Therefore, in SSc patients CYC treatment might foster angiogenesis mainly through the normalization of the endothelial cell invasive capacity and cell-matrix interactions. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.1905