Human CD133 ⁺ Progenitor Cells Promote the Healing of Diabetic Ischemic Ulcers by Paracrine Stimulation of Angiogenesis and Activation of Wnt Signaling

Abstract

Abstract-We evaluated the healing potential of human fetal aorta-derived CD133ϩ progenitor cells and their conditioned medium (CD133 ϩ CCM) in a new model of ischemic diabetic ulcer. Streptozotocin-induced diabetic mice underwent bilateral limb ischemia and wounding. One wound was covered with collagen containing 2ϫ10 4 CD133 ϩ or CD133 Ϫ cells or vehicle. The contralateral wound, covered with only collagen, served as control. Fetal CD133 ϩ cells expressed high levels of wingless (Wnt) genes, which were downregulated following differentiation into CD133Ϫ cells along with upregulation of Wnt antagonists secreted frizzled-related protein (sFRP)-1, -3, and -4. CD133ϩ cells accelerated wound closure as compared with CD133Ϫ or vehicle and promoted angiogenesis through stimulation of endothelial cell proliferation, migration, and survival by paracrine effects. CD133ϩ cells secreted high levels of vascular endothelial growth factor (VEGF)-A and interleukin (IL)-8. Consistently, CD133ϩ CCM accelerated wound closure and reparative angiogenesis, with this action abrogated by coadministering the Wnt antagonist sFRP-1 or neutralizing antibodies against VEGF-A or IL-8. In vitro, these effects were recapitulated following exposure of high-glucose-primed human umbilical vein endothelial cells to CD133 ϩ CCM, resulting in stimulation of migration, angiogenesis-like network formation and induction of Wnt expression. The promigratory and proangiogenic effect of CD133 ϩ CCM was blunted by sFRP-1, as well as antibodies against VEGF-A or IL-8. Key Words: ischemia Ⅲ wound healing Ⅲ diabetes Ⅲ stem cells Ⅲ angiogenesis C hronic wounds represent a relevant clinical and socioeconomic burden, with diabetic foot ulcers alone causing costs of 300 million pounds per annum to the United Kingdom National Health System. 1 Diabetic patients with foot ulcers associated with peripheral vascular disease manifest the worst outcome, with higher amputation and mortality rates than patients carrying nonischemic ulcers. 2,3 Although the efficacy of a topical gel formulation of recombinant human platelet-derived growth factor-BB was recently demonstrated in patients with nonischemic neuropathic ulcers, 4 most ischemic ulcers are refractory to conventional treatment and growth factor (GF) therapy. 5 Therefore, new strategies for the cure of life-threatening ischemic ulcers are urgently awaited.Preliminary evidence supports the potential of adult or fetal stem/progenitor cells for the healing of skin ulcers. 6 -8 However, because of the lack of an appropriate preclinical model, no information is available regarding the effectiveness of cell therapy on ischemic diabetic foot ulcers. The healing activity of stem cells is credited to their ability to transdifferentiate into the vascular and nonvascular components of injured tissue, as well as to secretion of GFs, which may activate endogenous modulators of angiogenesis in the recipient. 9 -11 Notably, fetal stem cells show significant advantages over their adult counterparts in terms of proliferative capa...

Diabetic microangiopathy: Pathogenetic insights and novel therapeutic approaches

“…While the percentage of EPCs (defined as CD34 + /CD133 + /VEGFR2 + cells) in a healthy adult subject is only 0.01% or less of peripheral blood mononuclear cells, in diabetic patients the number of EPCs is decreased, and later restored by intensive glycemic control [13,26]. EPCs have a therapeutic impact on cardiovascular tissue repair and regeneration by playing various roles in the formation of new blood vessels, including mobilization, migration, adhesion, differentiation of vascular cells, and the production of adequate circulating levels of growth factors and chemokines, necessary for tissue repair and regeneration [27][28][29][30]. In fact, experimental and clinical studies suggest that EPCs can home to sites of a pre-existing vessel, and from there form neovessels under the influence of VEGF, chemokines and integrins, including monocyte chemoattractant protein (MCP)-1, stromal cell derived factor-1 (SDF-1), angiopoietin (Ang-1) and the α4β1 integrin [31][32][33][34][35].…”

Wound Healing Angiogenesis: Innovations and Challenges in Acute and Chronic Wound Healing

“…11 One method to circumvent this issue is the application of exogenous adult or fetal progenitor cells (FPCs) to chronic wound beds. 12 Commonly expressing the EPC surface markers CD133, CD34, and VEGF receptor-2 (KDR), these cells can differentiate into both vascular endothelial and perivascular (mural) cells. 2 In addition, CD133-positive cells generate proangiogenic TARGET ARTICLES …”

“…In a recent study, fetal CD133-positive cells (FPC133 + ), isolated from human fetal aortas and expanded as previously described, 2 were used to stimulate ischemic wound healing in diabetic mice using a collagen-based delivery system. 12 Both FPC133 + and FPC133 + -conditioned media accelerate rates of wound closure, increase EC proliferation, and promote wound revascularization. Strikingly, a minimal number of vascular-associated FPC133 + are observed in wounds at 3 days postinjury/transplantation, yet the proangiogenic effects persisted for 7 days, suggesting an indirect (paracrine) mechanism that sustains FPC functionality postinjury.…”

Isolation of endothelial progenitor cells from human adipose tissue

“…It has been noted in some previous studies that EPCs are detected, and only at low numbers, in umbilical cord blood (Finney et al, 2006;Lin et al, 2011;Moon et al, 2013;Phuc et al, 2012), bone marrow (Ii, 2010) and peripheral blood (Donndorf et al, 2015). These EPCs have been successfully applied to treat ischemia-related diseases, such as hindlimb ischemia (Flex et al, 2016;Yu et al, 2015), stroke (Bai et al, 2015;, diabetic ulcer (Barcelos et al, 2009;Tam et al, 2015), and myocardial infarction (Mehmood et al, 2015;Sheng et al, 2015).…”

“…EPCs have been used effectively to treat hindlimb ischemia (Flex et al, 2016;Yu et al, 2015), stroke (Bai et al, 2015;, diabetic ulcer (Barcelos et al, 2009;Tam et al, 2015), and myocardial infarction (Mehmood et al, 2015;Sheng et al, 2015). However, the greatest limitation of EPC-based transplantation is the scarcity of EPCs; unlike other stem cells, EPCs exist in umbilical cord blood (Finney et al, 2006;Lin et al, 2011;Moon et al, 2013;Phuc et al, 2012), bone marrow (Ii, 2010) and peripheral blood (Donndorf et al, 2015), with extremely low numbers, and have slow proliferation in vitro.…”