An Assessment of the Functional State of Endothelial Colony Forming Cells from Patients with Diabetes Mellitus and Chronic Limb Threatening Ischemia

Chronic limb threatening ischemia (CLTI) is the most severe form of peripheral vascular disease which can lead to amputation with a high associated mortality rate. Endothelial colony forming cells (ECFCs) show potential as a cell therapy to revascularize the limbs of individuals with CLTI. However, autologous ECFCs from patient peripheral blood (PB) have been reported to have a dysfunctional phenotype. We investigated this disease phenotype in individuals with CLTI, with and without diabetes mellitus (DM), to determine ECFC suitability as an autologous cell therapy. PB-ECFCs were isolated from age-matched controls, individuals with DM, and individuals with CLTI, with and without DM. The frequency of isolating ECFCs from this donor cohort was calculated. Furthermore, in vitro characterization assays were performed (growth kinetics, angiogenic properties, and reactive oxygen species (ROS) levels) and compared between donor groups. We report a significantly increased frequency of ECFCs from individuals with CLTI, with and without DM. Furthermore, our results demonstrate no significant disease related effect on the in vitro functional properties of ECFCs between cohorts. However, there is a significantly higher in vitro angiogenic capacity in individuals with DM vs age-matched controls. Our results demonstrate that ECFCs can be isolated in individuals with CLTI, with and without DM, and that ECFC functionality is similar between cohorts. Therefore, if the 70% isolation efficiency from CLTI cohorts is overcome, then autologous PB-ECFCs may be a suitable therapeutic for CLTI. Further analysis is needed to determine the critical quality attributes of ECFCs from this patient population. Significance StatementTo the authors knowledge, this paper shows for the first time that endothelial colony forming cells can be isolated from individuals with chronic limb threatening ischemia, with and without diabetes. Additionally, we show a significantly higher frequency of endothelial colony forming cells isolated from chronic limb threatening ischemia patient cohorts. There is no significant difference in endothelial colony forming cells between age-matched controls and chronic limb threatening ischemia patient with and without diabetes mellitus in vitro, potentially suggesting an autologous approach may be a viable therapeutic option in the future.