E-Selectin Mediated Adhesion and Migration of Endothelial Colony Forming Cells Is Enhanced by SDF-1α/CXCR4

Abstract

ObjectiveEndothelial-colony forming cells (ECFCs) can be readily expanded from human umbilical cord blood and can facilitate repair of endothelial injury. E-selectin and SDF-1α are produced following endothelial injury and can regulate endothelial progenitor homing. Mechanisms of vascular repair specific to the mode of injury have not been well described in homogenous cell populations such as ECFCs and are needed for development of more effective vascular repair strategies.Methods and ResultsLipopolysaccharide (LPS)-induced endotoxic injury to mature human umbilical vein endothelial cells (HUVEC) was compared with hypoxic and radiation injury. E-selectin expression in HUVEC cells is markedly increased (208-fold) following LPS-induced injury and facilitates increased ECFC adhesion and migration function in vitro. SDF-1α expression remains unchanged in LPS-treated HUVEC cells but increases more than 2 fold in fibroblasts undergoing similar endotoxic injury. SDF-1α induces expression of E-selectin ligands on ECFCs and facilitates greater E-selectin-mediated adhesion and migration of ECFCs in a CXCR4-dependent manner. Induction of E-selectin expression in HUVECs following hypoxic or radiation injury is negligible, however, while SDF-1α is increased markedly following hypoxia, highlighting injury-specific synergism between mediators of vascular repair.ConclusionE-selectin mediates adhesion and migration of ECFCs following endotoxic endothelial injury. SDF-1α augments E-selectin mediated ECFC adhesion and migration in a CXCR4-dependent manner.

Human Endothelial Colony-Forming Cells Protect against Acute Kidney Injury

“…18 After isolation, ECFCs were cultured in EBM-2 Q8 medium supplemented with SingleQuot supplements (Lonza, Basel, Switzerland), 10% (v/v) fetal bovine serum, and 1% (v/v) 10,000 U/mL penicillin/ 10,000 mg/mL streptomycin/25 mg/mL amphotericin, as described. 18 Cells were seeded onto tissue culture plates precoated with gelatin at 37 C, 5% CO 2 , in a humidified incubator. Before injection, cells (passage 3 to 4) were detached using trypsin-EDTA, washed twice in 1Â phosphate-buffered saline (PBS), and resuspended in 1Â PBS at a final concentration of 10 7 cells/mL.…”

“…By flow cytometry, ECFCs (passage 4, n Z 4) expressed high levels of CD31 (82.5% AE 5.7% positive) and vascular endothelial growth factor receptor 2 (88.5% AE 2.4%), but lacked significant CD45 (0.5% AE 0.2%), CD14 (0.9% AE 0.3%), and CD133 (0.8% AE 0.3%) expression, consistent with our previous report. 18 The effects of human ECFCs were studied in NOD-SCID mice subjected to 30 minutes of bilateral kidney I/R. Compared with sham-operated on mice, I/R increased plasma creatinine levels at 24 and 72 hours after reperfusion (Figure 1 ½F1 ½F1 , A and B).…”

Regenerative Therapy and Immune Modulation Using Umbilical Cord Blood–Derived Cells

“…We recently demonstrated that endothelial cells produced increased levels of stromal cellederived factor (SDF)-1a injury compared with hypoxic or radiationassociated injury. The migration of ECFCs, likewise, was mediated via distinct mechanisms with increased expression of E-selectin ligands on ECFCs induced by SDF-1a binding to CXCR4 after LPS-induced injury of endothelial cells [43]. The extent to which specific angiogenic cells or EPCs are mobilized into the peripheral circulation may provide a useful prognostic biomarker, with specific subsets of circulating CD34-positive angiogenic cells correlating with cardiovascular risk and the number of endothelial cluster-forming cells Q 5 correlating with Framingham risk scores [44,45].…”

The Role of Synthetic Extracellular Matrices in Endothelial Progenitor Cell Homing for Treatment of Vascular Disease

“…Herein, certain matrix effectors, cytokines, and chemokines may be delivered to shift the balance towards promoting EPC homing to the target tissue. 73,81 Direct and indirect interactions between such factors and components of the ECM dictate how they are presented to and subsequently stimulate the surrounding cells. 67 Therefore, control over the spatiotemporal presentation of factors is crucial for the intended biological effect to be achieved.…”

“…31,46 EPC mobilization and homing is a multi-step process involving detachment from their steady state bone marrow (BM) niches, entry into circulation, rolling along vessel endothelium, transmigration, and adhesion to denuded extracellular matrix (ECM) where they may participate in neovessel formation. 45,73 All of these processes are under the tight regulation of chemokines and their receptors. However, these mechanisms are often interrupted in pathological conditions partly due to matrix modulation and an imbalance in factor presentation at the tissue level.…”