Endothelial Progenitor Cells In Neovascularization Research Articles

Enumeration and functional investigation of endothelial progenitor cells in neovascularization of diabetic foot ulcer rats with a Chinese 2-herb formula.

We investigated the effect of a Chinese 2-herb formula (NF3) on the enumeration and angiogenic differentiation of endothelial progenitor cells (EPCs) in diabetic foot ulcer rats. EPCs and stromal cell-derived factor-1α (SDF-1α) were quantified by flow cytometry and ELISA, respectively. In vitro angiogenesis assays included proliferation, adhesion, migration and tube formation. Our result demonstrated that NF3 (0.98 g/kg) could significantly enhance the circulating CD34(+) /VEGFR2(+) /CD45(-) EPCs levels in diabetic foot ulcer rats by 60% (P < 0.05) through the partial elevation of SDF-1α, restoring the mobilization ability of EPCs for wound neovascularization. We successfully isolated the BM-derived EPCs to study their angiogenic potential after NF3 treatment. BM-derived EPCs significantly expressed cell surface markers of CD34, CD146 and VEGFR2 (P < 0.05 - 0.01). NF3 could significantly stimulate the proliferation and attachment ability of EPCs dose-dependently (P < 0.01-0.001). Besides, NF3 could significantly augment EPCs migration (P < 0.001) and tube formation (P < 0.01-0.001). NF3 modulated diabetic wound healing through regulation of systemic EPCs level and increase in local vascular formation.

The role of fucosylation in the promotion of endothelial progenitor cells in neovascularization and bone repair

Bone marrow-derived endothelial progenitor cells (EPCs) are being tested as a therapy to treat a variety of ischemic diseases. Poor homing to targeted tissues is one of the major factors limiting the therapeutic efficacy of EPCs. Here, we show that human cord blood-derived EPCs expressed little sialyl Lewis X (sLex) antigen that is necessary for selectin-mediated cell–cell interactions. Expression of α1,3-fucosyltransferase VI (FucT VI) in the EPCs enhanced sLex synthesis, E- and P-selectin-binding, and EPC adhesion to tumor necrosis factor-α-stimulated human umbilical vein endothelial cells in culture. In a mouse model of hind limb ischemia, in which EPCs were injected intravenously, FucT VI expression increased EPC homing, neovascularization, and blood flow in ischemic muscles. In another mouse model of femoral fracture, FucT VI-expressing EPCs were more efficient than control EPCs in targeting to peri-fracture tissues to enhance angiogenesis, blood flow and bone repair. These results indicate that fucosylated EPCs may be used to as an improved cellular source to treat ischemic diseases.

Role of vascular endothelial progenitor cells in construction of new vascular loop

Since bone marrow-derived endothelial progenitor cells (EPCs) have been detected in adult peripheral blood, the mode of vasculogenesis in the adult tissue has caught attention in field of vascularization research. To confirm the role of EPCs in construction of new vascular loop, we took the biomaterial scaffold implanted into adult rat as an experimental model to observe and examine the actions of the EPCs in neovascularization of the material by immunohistochemistry and transmission electron microscopy. Additionally, by establishing a chemotactic migration model for vascular endothelial cells (ECs) and EPCs, the migrations of ECs and EPCs were explored in simulations. The results of 20,000 simulations showed that the number of the vascular loops assisted by the EPCs was 2–5 times that of the vascular sprouts being naturally joined. Based on the results of experiments and simulations, we conclude that the EPCs are able to assist the angiogenic sprouts in joining under the condition of plenty of the EPCs being mobilized, which aggregate at sites close to sprout tips, forming a cell cord and differentiating to ECs in situ, and become vessel segments between neighboring sprouts. This suggests that there is a difference between the adult and embryo in the manner of vasculogenesis and that a small number of EPCs can play an important role to make the new blood vessels achieve rapid functionalization.

Contribution of endothelial progenitor cells to neovascularization

Endothelial progenitor cells (EPCs) are a cell population mobilized from bone marrow into the peripheral circulation and recruited into sites of vessel injury to participate in blood vessel formation in both physiological and pathological conditions. Due to the lack of unique surface markers and different isolation methods, EPCs represent heterogeneous cell populations including cells of myeloid or endothelial origin. Evidence suggests that EPCs play a critical role in postnatal blood vessel formation and vascular homeostasis and provide a promising therapy for vascular disease. However, the mechanisms by which EPCs participate in new vessel formation are still incompletely understood. We review the process of EPCs in neovascularization including EPC mobilization, migration, adhesion and effect on new vessel formation, in an attempt to better understand the underlying mechanisms and to provide potential effective management for the treatment of patients with vascular disease.

Involvement of Bone Marrow-Derived Endothelial Progenitor Cells in Neovascularization During the Corpus Luteum Formation.

Involvement of Bone Marrow-Derived Endothelial Progenitor Cells in Neovascularization During the Corpus Luteum Formation.

323 The Role of Endothelial Progenitor Cells in Neovascularization of Ischemic Retina Through Sdf-1/Cxcr4 Axis in Oxygen-Induced Retinopathy Rat Model

Retinopathy of prematurity (ROP) is a common cause of blindness in preterm infants worldwide, despite laser treatment. Animal models of oxygeninduced retinopathy (OIR) have been developed to investigate physiological events that lead to the occurrence of this disease. It is known that endothelial progenitor cells (EPCs), derived from bone-marrow, are involved in vascular repair and neovascularization. In the present study we investigate the retinal expression of the SDF-1/ CXCR4 axis, its role in the recruitment of EPCs to the hypoxic retina, and the relationship between these cells and the development of neovascularization in a 50/10 OIR rat model. Our results show increased production of SDF-1 by endothelial cells and neurons in OIR retinas, and enhanced expression of CXCR4 mainly in Muller cells. We have also found in peripheral blood of OIR rats a decreased number of colony-forming units of EPCs. Whether this is due to the presence of functionally impaired EPCs or to the inability of an exhausted bone-marrow to produce enough progenitor cells to cope with the high demands of the process of retinal neovacularization, remains unanswered. We demonstrate in this study that SDF-1/CXCR4 axis, EPCs dysfunction and probably Muller cells, are involved in retinal neovascularization in a 50/10 rat model of OIR. These results warrant further studies.

Proteases and receptors in the recruitment of endothelial progenitor cells in neovascularization

Since the initial discovery of endothelial progenitor cells (EPC), and their promise in increasing angiogenesis and vasculogenesis, a myriad of papers have highlighted their potential application in experimental and clinical neovascularization and in tissue engineering. However, promising reports are contrasted by other studies that could not find a role for EPC in neovascularization. Presently, two types of endothelial progenitor cell populations are recognized. The first population provides early-outgrowth CD34+/VEGFR-2+ cells, or colony-forming unit endothelial cells (CFU-EC), which represent myeloid cells with some endothelial properties, but no ability to form endothelial colonies. They can stimulate neovascularization by paracrine means, but are not incorporated in the endothelial lining themselves. The second population generates the late-outgrowth endothelial colony-forming cells (ECFC) from a very scant blood-derived cell population. ECFC have a very high proliferative potential, can insert into the endothelial lining of new blood vessels, and can also form endothelial tubes by themselves after stimulation with the proper angiogenic stimulus. This review surveys the mobilization of progenitor cells from the bone marrow, the homing of EPC (CFU-EC) to areas of neovascularization, and the participation of EPC (ECFC) in the endothelial lining of newly formed blood vessels. Specific emphasis has been placed on the role of proteases, which include serine proteases, including urokinase, L-cathepsin, and several ADAM- and matrix metalloproteinases. The specific properties of ECFC make them a potential source of cells for tissue engineering applications, but much has to be learned about their nature, origin and properties.

Inflammation resolution: Does the bone marrow have a say?

American Journal of HematologyVolume 83, Issue 6 p. 435-436 CommentaryFree Access Inflammation resolution: Does the bone marrow have a say?† Mario Romano, Corresponding Author Mario Romano [email protected] Department of Biological Sciences and Aging Research Center, “Gabriele D'Annunzio” University Foundation, Chieti-Pescara, ItalyDipartimento di Scienze Biomediche, Universitá “G. D'Annunzio” Chieti-Pescara, Ce.S.I. Via Colle dell'Ara, 66013 Chieti, ItalySearch for more papers by this author Mario Romano, Corresponding Author Mario Romano [email protected] Department of Biological Sciences and Aging Research Center, “Gabriele D'Annunzio” University Foundation, Chieti-Pescara, ItalyDipartimento di Scienze Biomediche, Universitá “G. D'Annunzio” Chieti-Pescara, Ce.S.I. Via Colle dell'Ara, 66013 Chieti, ItalySearch for more papers by this author First published: 10 April 2008 https://doi.org/10.1002/ajh.21202Citations: 7 † Conflict of interest: Nothing to report. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. References 1 Serhan CN,Yacoubian S,Yang R. Anti-inflammatory and proresolving lipid mediators. Annu Rev Pathol 2008; 3: 279– 312. 2 Poulsen RC,Gotlinger KH,Serhan CN, et al. Identification of inflammatory and pro-resolving lipid mediators in bone marrow and their lipidomic profiles with ovariectomy and omega-3 intake. Am J Hematol 10.1002/ajh.21170. 3 Serbina NV,Pamer EG. Monocyte emigration from bone marrow during bacterial infection requires signals mediated by chemokine receptor CCR2. Nat Immunol 2006; 7: 311– 317. 4 Tsou CL,Peters W,Si Y, et al. Critical roles for CCR2 and MCP-3 in monocyte mobilization from bone marrow and recruitment to inflammatory sites. J Clin Invest 2007; 117: 902– 909. 5 Chamberlain G,Fox J,Ashton B, et al. Concise review: Mesenchymal stem cells: their phenotype, differentiation capacity, immunological features, and potential for homing. Stem Cells 2007; 25: 2739– 2749. 6 Takahashi T,Kalka C,Masuda H, et al. Ischemia- and cytokine-induced mobilization of bone marrow-derived endothelial progenitor cells for neovascularization. Nat Med 1999; 5: 434– 438. 7 Wada K,Arita M,Nakajima A, et al. Leukotriene B4 and lipoxin A4 are regulatory signals for neural stem cell proliferation and differentiation. FASEB J 2006; 20: 1785– 1792. 8 Viswanathan A,Painter RG,Lanson NAJr, et al. Functional expression of N-formyl peptide receptors in human bone marrow-derived mesenchymal stem cells. Stem Cells 2007; 25: 1263– 1269. 9 Rhee Y,Paik MJ,Kim KR, et al. Plasma free fatty acid level patterns according to cardiovascular risk status in postmenopausal women. Clin Chim Acta, in press. 10 Murphy E,Steenbergen C. Gender-based differences in mechanisms of protection in myocardial ischemia-reperfusion injury. Cardiovasc Res 2007; 75: 478– 486. 11 Urbich C,Dimmeler S. Endothelial progenitor cells: Characterization and role in vascular biology. Circ Res 2004; 95: 343– 353. 12 Kinnaird T,Stabile E,Burnett MS, et al. Local delivery of marrow-derived stromal cells augments collateral perfusion through paracrine mechanisms. Circulation 2004; 109: 1543– 1549. 13 Werner N,Kosiol S,Schiegl T, et al. Circulating endothelial progenitor cells and cardiovascular outcomes. N Engl J Med 2005; 353: 999– 1007. 14 Fadini GP,de Kreutzenberg S,Albiero M, et al. Gender differences in endothelial progenitor cells and cardiovascular risk profile: The role of female estrogens. Arterioscler Thromb Vasc Biol, in press. 15 Iwakura A,Shastry S,Luedemann C, et al. Estradiol enhances recovery after myocardial infarction by augmenting incorporation of bone marrow-derived endothelial progenitor cells into sites of ischemia-induced neovascularization via endothelial nitric oxide synthase-mediated activation of matrix metalloproteinase-9. Circulation 2006; 113: 1605– 1614. 16 Lee JH,O'Keefe JH,Lavie CJ, et al. Omega3 fatty acids for cardioprotection. Mayo Clin Proc 2008; 83: 324– 332. 17 Packard RR,Libby P. Inflammation in atherosclerosis: From vascular biology to biomarker discovery and risk prediction. Clin Chem 2008; 54: 24– 38. Citing Literature Volume83, Issue6June 2008Pages 435-436 ReferencesRelatedInformation

Decrease and dysfunction of endothelial progenitor cells in umbilical cord blood with maternal pre‐eclampsia

The pre-eclampsia is characterized by placental defective angiogenesis and maternal vascular/endothelial dysfunction. Recently, the decrease and senescence of endothelial progenitor cells (EPC) has been observed in maternal circulation with pre-eclampsia. Given the essential involvement of EPC in neovascularization and reendothelialization, we investigate whether or not the depletion of EPC is existent in placental/fetal circulation with maternal pre-eclampsia. Samples of venous cord blood were collected during the labor of preeclamptic mothers (n = 14) and normotensive controls (n = 10). Circulating EPC were enumerated as AC133+/KDR+ cells via fluorescence-activated cell sorting (FACS) analysis. Additionally, EPC were expanded in vitro and identified by DiI-acLDL uptake and lectin staining by direct fluorescent staining under a laser scanning confocal microscope. EPC proliferation, migration and vasculogenesis activities were determined by MTT, modified Boyden chamber assay and in vitro vasculogenensis assay. The placental/fetal circulating EPC numbers were significantly decreased in the pre-eclampsia group compared with the control (median, 200; range, 100-440 cells/mL vs 390; 270-440 cells/mL, P < 0.001), and after in vitro cultivation the numbers of EPC also decreased in pre-eclampsia group (19.5; 5.0-32.0 vs 39.5; 31.2-52.0 EPC/x200 field; P < 0.001). Both circulating EPC and cultivated EPC were inversely correlated with cord blood level of soluble fms-like tyrosine kinase 1 (sFlt-1). In addition, the EPC from patients with pre-eclampsia were significantly impaired in their proliferation, migration and vasculogenesis capacities. The present study documented the decrease and dysfunction of placental/fetal circulating EPC in patients with pre-eclampsia. The alteration is probably associated with the increased sFlt-1 levels in the umbilical cord blood.

Circulating Endothelial Progenitor Cells, C-Reactive Protein and Severity of Coronary Stenosis in Chinese Patients with Coronary Artery Disease

We sought to investigate whether numbers and activity of circulating endothelial progenitor cells (EPCs) correlate with severity of coronary stenosis as well as cardiovascular risk factors in patients with stable coronary artery disease (CAD). Number of circulating EPCs was analyzed in 104 consecutive patients with proven or clinically suspected CAD. Adhesive and migratory activity was also determined. The number of EPCs was lower in patients with a single diseased coronary artery (Group II, n=35, p<0.05 vs. Group I) or multiple diseased arteries (Group III, n=25, p<0.01 vs. Group I, p<0.05 vs. Group II) compared to those with normal coronary arteries (Group I, n=44). The number of EPCs was also related with angiographic Gensini score (r=-0.355, p=0.006). In addition, concentrations of C-reactive protein (CRP) were elevated in patients with CAD, and positively correlated with Gensini score (r=0.476, p=0.001). As for the risk factors, the number of EPCs was also inversely correlated with age (p=0.001), high sensitivity-CRP (p=0.012), hypertension (p=0.042) and family history of CAD (p=0.043). Most importantly, the migratory capacity of EPCs was compromised in patients with CAD, and inversely correlated with the angiographic Gensini score (r=-0.315, p=0.021). EPCs isolated from patients with CAD also showed an impaired adhesive activity (p<0.05). In conclusion, in patients with stable CAD, reduction in the number and impairment in the function of circulating EPCs were correlated with the severity of coronary stenosis. CRP may play an important role in reducing the number of EPCs and accelerating atherosclerosis. Given the important role of EPCs in neovascularization of ischemic tissue, a decrease in the number and activity of EPCs may contribute to the impaired vascularization in patients with CAD.

Therapeutic angiogenesis and vasculogenesis for ischemic disease: part II: cell-based therapies.

### Endothelial Progenitor Cells and Postnatal Vasculogenesis: Experimental Evidence The option of performing full-scale endothelial cell transplantation to optimize local neovascularization is daunting if even feasible. An alternative, attractive strategy is designed to exploit the conceptual notion that endothelial cells and hematopoietic stem cells were ultimately derived from a common precursor, the putative hemangioblast. Hematopoietic stem cells had been shown previously to be present in circulating blood, in quantities sufficient to permit their harvesting and readministration for autologous, in lieu of bone marrow, transplantation. The related descendants, endothelial progenitor cells, can be detected in the peripheral circulation.1,2 Initially, Flk-1 and a second antigen, CD34, shared by angioblasts and hematopoietic stem cells were used to isolate putative angioblasts from the leukocyte fraction of peripheral blood.1 Meanwhile, endothelial progenitor cells were isolated from human umbilical cord blood,3 bone marrow–derived mononuclear cells,4 and CD34+ or CD133+ hematopoietic stem cells1,5 and were successfully ex vivo expanded with the use of human peripheral blood mononuclear cells.6 These cells differentiated into endothelial cells, as shown by expression of various endothelial proteins (KDR, von Willebrand factor, endothelial nitric oxide synthase, VE-cadherin, CD146) and uptake of Dil-acetylated LDL and binding of lectin.1,7 In animal models of ischemia, heterologous, homologous, and autologous endothelial progenitor cells were shown to incorporate into sites of active neovascularization in ischemic and tumor tissue. Blood flow recovery and capillary density were markedly improved, and the rate of limb loss was significantly reduced after transplantation of human peripheral blood–derived endothelial progenitor cells8,9 or bone marrow mononuclear cells.10 Likewise, infusion of peripheral blood–derived endothelial progenitor cells,11 bone marrow mononuclear cells,12 or purified CD34+ cells13 improved neovascularization and myocardial function after infarction. Isolated CD34+ cells also increased impaired blood flow in diabetic mice.14 These findings provide evidence that exogenously …

Post-natal endothelial progenitor cells for neovascularization in tissue regeneration.

The isolation of endothelial progenitor cells (EPCs) derived from bone marrow (BM) was an outstanding event in the recognition of 'de novo vessel formation' in adults occurring as physiological and pathological responses. The finding that EPCs home to sites of neovascularization and differentiate into endothelial cells (ECs) in situ is consistent with 'vasculogenesis', a critical paradigm well described for embryonic neovascularization, but proposed recently in adults in which a reservoir of stem or progenitor cells contributes to vascular organogenesis. EPCs have also been considered as therapeutic agents to supply the potent origin of neovascularization under pathological conditions. This review provides an update of EPC biology as well as highlighting their potential use for therapeutic regeneration.

Endothelial progenitor cells: mobilization, differentiation, and homing.

Postnatal bone marrow contains a subtype of progenitor cells that have the capacity to migrate to the peripheral circulation and to differentiate into mature endothelial cells. Therefore, these cells have been termed endothelial progenitor cells (EPCs). The isolation of EPCs by adherence culture or magnetic microbeads has been described. In general, EPCs are characterized by the expression of 3 markers, CD133, CD34, and the vascular endothelial growth factor receptor-2. During differentiation, EPCs obviously lose CD133 and start to express CD31, vascular endothelial cadherin, and von Willebrand factor. EPCs seem to participate in endothelial repair and neovascularization of ischemic organs. Clinical studies using EPCs for neovascularization have just been started; however, the mechanisms stimulating or inhibiting the differentiation of EPC in vivo and the signals causing their migration and homing to sites of injured endothelium or extravascular tissue are largely unknown at present. Thus, future studies will help to explore areas of potential basic research and clinical application of EPCs.

Ischemia- and cytokine-induced mobilization of bone marrow-derived endothelial progenitor cells for neovascularization.

Endothelial progenitor cells (EPCs) have been isolated from circulating mononuclear cells in human peripheral blood and shown to be incorporated into foci of neovascularization, consistent with postnatal vasculogenesis. We determined whether endogenous stimuli (tissue ischemia) and exogenous cytokine therapy (granulocyte macrophage-colony stimulating factor, GM-CSF) mobilize EPCs and thereby contribute to neovascularization of ischemic tissues. The development of regional ischemia in both mice and rabbits increased the frequency of circulating EPCs. In mice, the effect of ischemia-induced EPC mobilization was demonstrated by enhanced ocular neovascularization after cornea micropocket surgery in mice with hindlimb ischemia compared with that in non-ischemic control mice. In rabbits with hindlimb ischemia, circulating EPCs were further augmented after pretreatment with GM-CSF, with a corresponding improvement in hindlimb neovascularization. There was direct evidence that EPCs that contributed to enhanced corneal neovascularization were specifically mobilized from the bone marrow in response to ischemia and GM-CSF in mice transplanted with bone marrow from transgenic donors expressing beta-galactosidase transcriptionally regulated by the endothelial cell-specific Tie-2 promoter. These findings indicate that circulating EPCs are mobilized endogenously in response to tissue ischemia or exogenously by cytokine therapy and thereby augment neovascularization of ischemic tissues.