Intravenous Administration of Endothelial Colony-Forming Cells Overexpressing Integrin β1 Augments Angiogenesis in Ischemic Legs

Abstract

When injected directly into ischemic tissue in patients with peripheral artery disease, the reparative capacity of endothelial progenitor cells (EPCs) appears to be limited by their poor survival. We, therefore, attempted to improve the survival of transplanted EPCs through intravenous injection and gene modification. We anticipated that overexpression of integrin b 1 will enable injected EPCs to home to ischemic tissue, which abundantly express extracellular matrix proteins, the ligands for integrins. In addition, integrin b 1 has an independent angiogenesis-stimulating function. Human endothelial colony-forming cells (ECFCs; late-outgrowth EPCs) were transduced using a lentiviral vector encoding integrin b 1 (ITGB1) or enhanced green fluorescent protein (GFP). We then locally or systemically injected phosphate-buffered saline or the genetically modified ECFCs (GFP-ECFCs or ITGB1-ECFCs; 1 3 10 5 cells each) into NOD/Shi-scid, IL-2Rgnull mice whose right femoral arteries had been occluded 24 hours earlier. Upregulation of extracellular matrix proteins, including fibronectin, was apparent in the ischemic legs. Four weeks later, blood perfusion of the ischemic limb was significantly augmented only in the ITGB1-ECFC group. Scanning electron microscopy of vascular casts revealed increases in the perfused blood vessels in the ischemic legs of mice in the ITGB1-ECFC group and significant increases in the density of both capillaries and arterioles. Transplanted ECFC-derived vessels accounted for 28% 6 4.2% of the vessels in the ITGB1-ECFC group, with no cell fusion. Intravenous administration of ECFCs engineered to home to ischemic tissue appears to efficiently mediate therapeutic angiogenesis in a mouse model of peripheral artery disease. STEM CELLS TRANSLATIONAL MEDICINE 2016;5:218-226 SIGNIFICANCEThe intravenous administration of endothelial colony-forming cells (ECFCs) genetically modified to overexpress integrin b 1 effectively stimulated angiogenesis in ischemic mouse hindlimbs. Transplanted ECFCs were observed in the ischemic leg tissue, even at the chronic stage. Moreover, the cells appeared functional, as evidenced by the improved blood flow. The cell type used (ECFCs), the route of administration (intravenous, not directly injected into the affected area), and the use of ligand-receptor interactions (extracellular matrix and integrins) for homing represent substantial advantages over previously reported cell therapies for the treatment of peripheral artery disease.

Therapeutic Potential of Endothelial Colony-Forming Cells in Ischemic Disease: Strategies to Improve their Regenerative Efficacy

“…However, lentiviral vector gene delivery of a constitutively active Akt1 mutant was able to rescue the pro-angiogenic activity of SA men-derived ECFCs by recruiting eNOS, thereby restoring their therapeutic outcome in vivo [ 229 ]. A slightly different approach consisted in forcing ECFCs to overexpress integrin β1 [ 230 ], which promotes ECFC binding to extracellular matrix proteins in ischemic tissues [ 231 ] and further exerts independent angiogenic effects [ 232 ]. ECFCs were engineered with a lentivirus encoding for murine integrin β1 and injected, either locally or intravenously, in a murine model of hindlimb ischemia [ 230 ].…”

TRPC3‐mediated Ca2+ signals as a promising strategy to boost therapeutic angiogenesis in failing hearts: The role of autologous endothelial colony forming cells

“…ECFCs are emerging as suitable candidates for cell‐based therapy of ischemic diseases by virtue of their ability to paracrinally stimulate local angiogenesis and preserve cardiomyocyte viability and to physically engraft within nascent vasculature (Watt et al, ; Yoder, ). Accordingly, both PB‐ and UCB‐derived ECFCs may cause de novo vessel formation and functional recovery of blood flow in several rodent models of hindlimb ischemia (Flex et al, ; Goto et al, ; Kang, Coggins, Xiao, Rosenzweig, & Bischoff, ; Patel et al, ). A recent study further showed that VEGFR‐2 (KDR/Flk‐1), the receptor isoform that mediates the pro‐angiogenic effects of VEGF on EPCs (Moccia, Dragoni, et al, ; Rabbany, Heissig, Hattori, & Rafii, ), is also key to ECFCs‐dependent revascularization (Joo et al, ).…”

MFSD2A Promotes Endothelial Generation of Inflammation-Resolving Lipid Mediators and Reduces Colitis in Mice

“…For this reason, to establish whether MFSD2A overexpression on endothelial cells could promote in vivo the resolution of intestinal inflammation, we choose the Dextran Sodium Sulfate (DSS)-induced model of acute colitis. Moreover, we took advantage of the capability of human endothelial colony-forming cells (ECFCs), to be recruited to ischemic or inflamed tissues 27 , where they remodel the vascular compartment 28 . We transduced mCherry-tagged human ECFCs with MFSD2A-GFP-carrying lentiviral particles (ECFCs-MFSD2A) or GFP-expressing ECFCs (ECFCs-GFP), as control.…”