Abstract 16676: Neovascularisation Potential of Blood Outgrowth Endothelial Cells From Patients With Severe Ischemic Cardiomyopathy
Purpose: Blood outgrowth endothelial cells (BOECs) mediate therapeutic neovascularisation in experimental models. Whether these cells can be culture-expanded and retain functional characteristics in patients with ischemic cardiomyopathy (ICMP) remains unknown.
Methods: We derived BOECs from 60-mL whole blood from 37 ICMP (LVEF≤45%) and 35 healthy subjects (CON) and analysed Dil-AcLDL uptake and BOEC-specific surface markers using flow cytometry. We studied neovascularisation potential in vitro using tube formation capacity on matrigel, measured secreted angiogenic factors by ELISA and quantified senescence by SA-β-GAL. We studied neovascularisation in the ischemic hind limb of nude mice after IM BOEC-injections (250,000 cells/mouse) or vehicle control (PBS) using high-resolution microcomputed tomography (μ-CT).
Results: An average of 3.4±0.5 BOEC-colony forming units (CFUs)/100x10^6 mononuclear cells (MNCs) was obtained in ICMP (age: 66±2y, LVEF: 31±2%, LVEDD: 56±1 mm) vs 2.5±0.4 CFUs/100x10^6 MNCs in CON (age: 36±2y) (P=0.12). In patients, BOEC-outgrowth did not correlate with the extent of LV systolic dysfunction or remodeling, and was not affected by cardiovascular risk factors. Endothelial lineage (VEGR2+/CD31+/CD146+) and progenitor (CD34+/CD133-) markers were comparable in ICMP and CON, whereas the panleukocyte marker CD45 was absent in all. Uptake of Dil-AcLDL was ≥94% in all clones from ICMP and CON, and in vitro tube length and number of intersections in ICMP and CON were comparable (n=15 vs 13, resp). Secretome analysis showed comparable levels of pro-angiogenic growth factor release for Angiopoietin-2, PLGF, FGF-2 and PDGFbb. The percentage of senescent BOECs was comparable in ICMP and CON (6±2%, n=16 vs 9±3%, n=13). Finally, μ-CT analysis confirmed improved neovascularisation after targeted IM injections of BOECs from CON and ICMP over PBS (n=5 mice/group).
Conclusions: BOECs can be successfully and consistently isolated and culture-expanded from patients with ICMP. In contrast to the impaired functionality of mononuclear bone marrow cells derived from ICMP, BOECs retain a robust pro-angiogenic profile in vitro and in vivo and hold promise for autologous cell therapy in advanced ischemic heart disease.
- Ischemic heart disease
- Heart failure
- Regenerative medicine stem cells
- Endothelial progenitor cell
- © 2013 by American Heart Association, Inc.