© 2001 American Heart Association, Inc.
Integrative Physiology |
Vascular Trauma Induces Rapid but Transient Mobilization of VEGFR2+AC133+ Endothelial Precursor Cells
From the Division of Hematology and Oncology (M.G., S.D., K.H., M.L.R., S.R.), Cornell University Medical College; W Randolph Burn Center (R.Y., H.H.) and Division of Cardiothoracic Surgery (L.G.), New York Presbyterian Hospital; and Imclone Systems Incorporated (D.H., L.W.), New York, NY.
Correspondence to Shahin Rafii, MD, Division of Hematology/Oncology, Cornell University Medical College, 1300 York Ave, Room C-606, New York, NY 10021. E-mail srafii{at}mail.med.cornell.edu
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Abstract—Bone marrow (BM)–derived circulating endothelial precursor cells (CEPs) are thought to play a role in postnatal angiogenesis. Emerging evidence suggests that angiogenic stress of vascular trauma may induce mobilization of CEPs to the peripheral circulation. In this regard, we studied the kinetics of CEP mobilization in two groups of patients who experienced acute vascular insult secondary to burns or coronary artery bypass grafting (CABG). In both burn and CABG patients, there was a consistent, rapid increase in the number of CEPs, determined by their surface expression pattern of vascular endothelial growth factor receptor 2 (VEGFR2), vascular endothelial cadherin (VE-cadherin), and AC133. Within the first 6 to 12 hours after injury, the percentage of CEPs in the peripheral blood of burn or CABG patients increased almost 50-fold, returning to basal levels within 48 to 72 hours. Mobilized cells also formed late-outgrowth endothelial colonies (CFU-ECs) in culture, indicating that a small, but significant, number of circulating endothelial cells were BM-derived CEPs. In parallel to the mobilization of CEPs, there was also a rapid elevation of VEGF plasma levels. Maximum VEGF levels were detected within 6 to 12 hours of vascular trauma and decreased to baseline levels after 48 to 72 hours. Acute elevation of VEGF in the mice plasma resulted in a similar kinetics of mobilization of VEGFR2+ cells. On the basis of these results, we propose that vascular trauma may induce release of chemokines, such as VEGF, that promotes rapid mobilization of CEPs to the peripheral circulation. Strategies to improve the mobilization and incorporation of CEPs may contribute to the acceleration of vascularization of the injured vascular tissue.
Key Words: circulating endothelial precursor cells\b • mobilization • vascular endothelial growth factor \b • vascular endothelial growth factor receptor 2 • AC133
|
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Vascular trauma, induced by burn or by mechanical disruption, such as during surgical procedures, leads to a cascade of events that result in the chemoattraction of inflammatory cells and other cell types to the site of injury.1 Production and release of proangiogenic factors such as VEGF and basic fibroblast growth factor 2 (FGF-2) may potentiate the recruitment of inflammatory cells including monocytes,2 as well as other nonhematopoietic cell types such as circulating endothelial precursor cells (CEPs),3 4 to the site of injured vascular tissue, accelerating vascular healing.
Vascular healing is a complex process and may require rapid endothelialization to prevent fatal complications such as thrombosis or bleeding. Two possible sources of endothelialization are (1) migration and co-option of preexisting vascular wall endothelial cells (ECs) or (2) recruitment of CEPs from the stem-cell reservoirs such as bone marrow (BM). CEPs may reflect the phenotype of embryonic angioblasts, which are migratory ECs with the capacity to circulate, proliferate, and differentiate into mature ECs but have neither acquired characteristic markers of mature ECs nor formed lumina.
We have shown that allogeneic sex-mismatched BM transplantation resulted in the transfer of CEPs to recipient dogs.5 In humans, evidence for CEPs originates from patients implanted with a left ventricular assist device (LVAD), where the surface of the titanium housing of LVADs is colonized with BM-derived circulating CD34+ EC-like cells.6 However, because BM contains both mature ECs as well as BM-derived CEPs, these studies did not conclusively demonstrate the existence of a phenotypically and functionally distinct population of CEPs. Moreover, discrimination between CEPs and mature ECs or hematopoietic cells is complicated by the fact that subsets of hematopoietic cells express markers similar to those of ECs.
In search of a BM-derived, CEP-specific marker, we have found that AC133, a novel hematopoietic stem-cell marker, is also expressed on subsets of CD34+ cells.7 AC133+ CEPs express vascular endothelial growth factor receptor 2 (VEGFR2) and are dependent on VEGF for survival and in vitro expansion. AC133+VEGFR2+ CEPs isolated from cord blood, BM, or fetal liver proliferate in vitro in an anchorage-independent manner and can be induced to undergo migration or differentiate into mature adherent AC133- mature ECs.7
Several studies have capitalized on the in vitro growth capacity and differentiation profile of CEPs to distinguish between mature fallout vessel-derived endothelium and BM-derived CEPs. Using fluorescent in situ hybridization analysis to detect the Y chromosome in blood samples from BM transplant recipients who received gender-mismatched stem cells, Lin et al8 could distinguish between vessel wall and BM-derived endothelial cells. They show that in vitro–derived ECs form adherent colonies during early phases of culture (9 days after plating) and undergo 6-fold expansion and are derived predominantly from the recipient vessel wall, whereas ECs derived from late-outgrowth endothelial colonies (CFU-ECs, 30 days after culture) undergo 98-fold expansion and mostly generate from transplanted donor BM cells. In this regard, the potential of forming late-outgrowth colonies and expression of AC133 provide for surrogate markers to identify and quantify the numbers of human BM-derived CEPs.
Because rapid endothelialization of denuded injured vessels is essential to avoid fatal complications, we hypothesized that elevation of plasma VEGF levels immediately after vascular trauma may promote CEP mobilization into the peripheral circulation. In the present study, we demonstrate that in burn patients and those who undergo coronary artery bypass grafting (CABG), there is a rapid elevation of VEGF levels followed by immediate mobilization, within 6 to 12 hours of vascular trauma, of VEGFR2+AC133+ cells into the peripheral circulation. Given that a significant number of VEGFR2+ cells have the capacity to form late-outgrowth colonies and also express the stem-cell marker AC133, they can be considered as BM-derived CEPs. These data suggest that CEPs may act as first-aid angiogenic modules rapidly mobilized to enhance the endothelialization of denuded prothrombotic injured vasculature. Isolation and ex vivo expansion of these cells may facilitate the development of strategies to augment and accelerate vascular healing in patients with profound vascular insufficiencies.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Collection of Peripheral Blood Samples and Isolation of Mononuclear Cells
Permission to perform these studies was approved by the investigational review board at Cornell University Medical College. Samples were taken from patients who had >15% burn injury (n=8). Peripheral blood (4 to 5 mL) was taken at 12, 24, 48, and 72 hours and on the 7th and 14th days. Blood (4 to 5 mL) was also taken from patients (n=7) who underwent CABG. Samples were taken preoperatively at 6, 12, 24, 48, and 72 hours and on the 4th day.
The blood samples from burn and CABG patients were collected in heparinized tubes. Blood (5 mL) was diluted with HBSS (Life Technologies) and overlaid on top of a Ficoll preparation (Accue Prep Lymphocytes, Accurate Chemical & Scientific Corp). The buffy coat, containing the peripheral blood mononuclear cells (PBMNCs), was isolated and washed twice in HBSS at 1800g for 10 minutes. Finally, the PBMNCs were resuspended in serum-free medium (X-vivo 20, BioWhittaker). These cells were studied for the expression of endothelial-specific markers and formation of late-outgrowth endothelial colonies.
Flow Cytometry Studies
PBMNCs, cultured in serum-free medium X-vivo 20, were
incubated with 1.5 µL FITC (green fluorescence) labeled high-affinity
nonneutralizing monoclonal antibody (MoAb) to VEGFR2 (clone
6.64, Imclone Systems Inc) and 1.5 µL phycoerythrin (PE; red
fluorescence) labeled anti-CD15 antibody (Sigma), for 20 minutes at
4°C. Nonviable cells were excluded by propidium iodide (PI; 30
µmol/L, Becton Dickinson). The number of positive cells was compared
with IgG isotype control (FITC, PE; Immunotech) and quantified using a
Coulter Elite flow cytometer (Coulter). Other endothelial markers
studied were vascular endothelial cadherin (VE-cadherin) (BV9 clone,
Imclone Systems Inc) and AC133 (Miltenyi Biotech). For analysis in burn
patients, samples taken from normal age and gender-matched subjects
were used as control, and preoperative samples were used as control in
the CABG patients.
Reverse Transcriptase–Polymerase Chain
Reaction (RT-PCR) Analysis of PBMNCs
Total RNA from PBMNCs of burn and CABG patients at
different time points was obtained using Tri-Zol (Life Technologies),
according to the manufacturer’s instructions. The first-strand cDNA
was synthesized using the T-Primed First Strand Kit (Amersham Pharmacia
Biotech Inc), amplified by Taq DNA polymerase (Advantage cDNA
Polymerase Mix, Clontech) in a 25-µL reaction mixture, including 10
mmol/L dNTP (MBI Fermentas Inc) and 10 µmol/L of each primer
(Genelink). PCR was performed using a PCR thermal cycler (MWG Biotech).
The PCR program used to amplify VEGFR2, VE-cadherin, and ß-actin had
the following parameters: 5 minutes initial denaturation at 94°C,
annealing at 60°C for 1 minute, and 30 seconds of elongation at
72°C. This initial cycle was followed by 35 cycles of denaturation at
94°C for 45 seconds, annealing at 60°C for 45 seconds, and 2
minutes of elongation at 72°C, followed by 7 minutes of extension at
72°C. Subsequently, PCR products were visualized in 1.5% ethidium
bromide–stained agarose gels. Human umbilical vein endothelial cell
(HUVEC) cDNA was used as a positive control. RNA from normal donors for
the burn patients and preoperative samples from the CABG patients were
used as a control for baseline mRNA expression.
Primers
ß-actin: ß-actin primer sequence (513
bp): sense: TCA TGT TTG AGA CCT TCA A; antisense: GTC TTT GCG GAT GTC CAC G
VEGFR2: VEGFR2 primer sequence (790 bp): sense: CTG GCA TGG TCT TCT GTG AAG CA; antisense: AAT ACC AGT GGA TGT GAT GCG G
VE-cadherin: VE-cadherin primer sequence (596 bp): sense: ACG GGA TGA CCA AGT ACA GC; antisense: ACA CAC TTT GGG CTG GTA GG
Late-Outgrowth Endothelial Colony Assay
To evaluate the potential of mobilized PBMNCs as
CEPs, we used a protocol developed by Lin et
al,8 with minor
modifications. Freshly isolated PBMNCs, obtained 12 hours after trauma,
were cultured in endothelial growth medium (M199, Gibco BRL)
supplemented with 20% FBS (HyClone), endothelial cell growth
factor (30 µg/mL), FGF (5 ng/mL, human recombinant basic FGF
[Sigma]), heparin (5 U/mL), penicillin (100 U/mL), streptomycin (100
µg/mL), and fungizone (0.25 µg/mL). These cells were placed on
12-well plates and coated with 0.2% gelatin. The plates were incubated
at 37°C in a humidified environment with 5%
CO2. This process resulted in attachment of
cells consisting mostly of monocytes or mature endothelial colonies on
the well plates. Nonadherent cells were transferred after 4 to 5 days
to other wells coated with 0.2% gelatin and grown in endothelial
growth medium. Each week, for up to 2 weeks, the nonadherent cells were
transferred to fresh plates to assess for the formation of
late-outgrowth colonies.
Endothelial colonies were identified by metabolic uptake of DiI-acetylated-LDL (DiI-Ac-LDL) by incubating the cells with 1 µg/mL of human DiI-Ac-LDL (PerImmune Inc) at 37°C for 5 hours and visualizing by fluorescence microscopy. For von Willebrand factor (vWF) staining, cells were rinsed with HBSS and fixed immediately with 4% paraformaldehyde for 10 minutes. A primary mouse antibody against human vWF (Dako) was used at 1:250 dilution. Biotinylated rat anti-mouse IgG (Vector Laboratories Inc) was used at 1:200 dilution. Streptavidin linked to FITC (Jackson ImmunoResearch Laboratories Inc) was used at a dilution of 1:200. Cells were visualized by fluorescence microscopy. HUVECs were used as positive control for DiI-Ac-LDL uptake and vWF staining. Adherent colonies incorporating DiI-Ac-LDL and coexpressing vWF, representing early outgrowths, were quantified every week. DiI-Ac-LDL+vWF+ colonies derived from passaged nonadherent cells, which formed between 6 to 8 weeks, were considered as late-outgrowth colonies (CFU-ECs). Samples from the healthy donors were used as control in the burn patients and preoperative samples were used as control in the CABG patients.
VEGF Plasma Determination
Quantitative determination of VEGF in the plasma of
patients or AdVEGF165-injected mice was
determined by a specific human or murine VEGF ELISA using the
Quantikine VEGF-ELISA kit (R&D Systems Inc), according to the
manufacturer’s instructions. Peripheral blood plasma samples were
obtained at different time points from the burn and CABG patients.
Plasma samples from healthy donors were used to determine the baseline
VEGF levels for the burn patients, whereas in CABG patients, this was
determined by analyzing the preoperative plasma levels of the patients.
Plasma of mice injected with AdNull was used as control. Both assays
have a sensitivity limit of 7 pg/mL. Samples were analyzed in
triplicate.
In Vivo Adenoviral Delivery of
VEGF
Immunocompetent mice (on BALB/C background), aged 8
weeks (>20 g) and sex-matched, were purchased from the Jackson
Laboratory (Bar Harber, Maine) and maintained in germ-free conditions.
Mice (n=6) received AdVEGF165
(1.5x108 pfu) or AdNull
(1.5x108 pfu) in a volume of 100 µL by
single intravenous administration on day 0.
AdVEGF165 is an Ad5-derived, E1a-, E3-deficient
(E1a–E3–E4+)
vector with an expression cassette in the E1a region containing the
mouse AdVEGF165 cDNA and driven by the
cytomegalovirus major immediate/early promoter/enhancer. The control
vector, AdNull, is similar in design, except that it contains no
transgene in the expression cassette.
Flow Cytometry Studies on Mouse
PBMNCs
Cells were costained with 1.5 µL of FITC-labeled
high-affinity MoAb to VEGFR2 (clone DC101, Imclone Systems Inc) and 1
µL of PE (red fluorescence) labeled anti-CD11b antibody (Pharmingen)
for 20 minutes at 4°C. The number of positive cells was compared with
IgG isotype control (FITC, PE; Pharmingen). PI (30 µmol/L) was used
to exclude the nonviable cells. The cells were analyzed by using the
Coulter Elite flow cytometer.
Statistical Analysis
A standard Student’s
t test was used to determine
statistical differences.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
VEGF Plasma Levels Increase After Vascular Trauma
VEGF plasma levels from both burn and CABG patients increased immediately after vascular trauma, which peaked between 6 to 12 hours after injury, and then decreased gradually over a 2-day period (Figures 1A
and 1B). VEGF levels were lower after 3 to 4 days
of injury. These results suggest that vascular trauma induces a rapid
but transient increase in plasma VEGF levels after
trauma.
|
Vascular Trauma Induces Mobilization
of PBMNCs Expressing mRNA for VEGFR2 and VE-Cadherin
We investigated whether the rapid increase in VEGF
levels correlated with an increase in the number of circulating
VEGFR2+ PBMNCs. Peripheral blood samples
from burn and CABG patients demonstrated VEGFR2 and VE-cadherin
expression at the mRNA level, as determined by RT-PCR
(Figures 2A and 2B). VEGFR2 and VE-cadherin mRNA were present
in the PBMNCs between 6 and 12 hours and then gradually decreased over
time. Control samples for burn and CABG patients had virtually
undetectable mRNA levels for any of these
markers.
|
Characterization of Mobilized
CEPs
The RT-PCR analysis of PBMNCs from burn and CABG
patients suggested that after vascular trauma, a population of cells
expressing VEGFR2 and VE-cadherin may be rapidly mobilized into the
peripheral circulation. These results were subsequently confirmed by
analysis of surface expression using flow cytometry (FACS).
Given that monocytes express Fc receptors and may give
rise to false-positive results, the PBMNCs were also costained with
CD15 to exclude mobilized cells of myeloid-monocytic lineage.
Confirming the RT-PCR results, FACS analysis of PBMNCs obtained from
burn and CABG patients showed a rapid increase in circulating
VEGFR2+ cells after 6 to 12 hours
(Figures 3 and 4). These cells were negative for the myeloid
marker CD15 (see
Figures 3A and 3B for a typical FACS profile). Samples from
burn patients showed an average of 20 655±4077
VEGFR2+CD15-
cells (5.1±1.04% of the total PBMNCs) mobilized 12 hours after burn
injury
(Figure 4A) and decreasing after 72 hours. On the other hand,
healthy donors had 0.10%±0.01 (535±127 cells) circulating
VEGFR2+CD15-
cells (P<0.05).
Similarly, in CABG patients, although the preoperative samples showed
915±107 (0.02±0.02% of the total PBMNCs)
VEGFR2+CD15-
cells, there was an average of 34 843±13 515 (8.4±3.2% of the
total PBMNCs)
VEGFR2+CD15-
cells mobilized 6 hours after surgery
(Figure 4B). In these patients, at 12 and 24 hours after
surgery, there was a sustained elevation of
VEGFR2+CD15-
cells with an average of 17 800±5823 (4.5±1.45% of the total
PBMNCs) and 11 467±4097 (2.8±1% of the total PBMNCs) cells
(Figure 4B), respectively. The number of
VEGFR2+CD15-
cells gradually decreased over a 3- to 4-day period, in both groups of
patients. The last peripheral blood sample from burn patients was taken
14 days after injury and had 664±257 (0.20±0.03% of the total
PBMNCs)
VEGFR2+CD15-
cells
(Figure 4A). Similarly, the last sample from CABG patients
was taken on the fourth day after surgery and showed 1329±408
(0.3±0.06% of the total PBMNCs)
VEGFR2+CD15-
cells
(Figure 4B). These results demonstrate the presence of a
small, but distinct, population of
VEGFR2+CD15-
cells within the PBMNC population of vascular trauma patients, which
rapidly gets mobilized within 6 to 12 hours after injury and then
decreases gradually over a period of days.
|
|
Phenotypic Analysis of the
VEGFR2+CD15-
Cells
The peripheral blood samples from burn and CABG
patients were further analyzed for the presence of other hematopoietic
and endothelial markers by flow cytometry. The 12-hour time point was
chosen, because it consistently showed, in both groups of patients, the
highest number of mobilized CEPs. Twelve hours after injury, in both
burn and CABG patients, there was a maximum increase in cells
expressing VE-cadherin and AC133
(Table),
which accompanied the maximum increase in VEGFR2 expression. There was
a mean increase of 15 987±4555 (5.1±1.04% of the total PBMNCs) and
15 544±3390 (4.5±1.45% of the total PBMNCs)
VE-cadherin+ cells at 12 hours, in burn and
CABG patients, respectively
(Table).
Similarly, the increase in AC133+ cells in
burn and CABG patients was 8769±2019 (2.2±0.5% of the total PBMNCs)
and 8342±2109 (2.1±0.51% of the total PBMNCs), respectively
(Table).
Furthermore, as shown for VEGFR2, expression of these markers in the
PBMNC population gradually decreased over a 2- to 3-day period (data
not shown). These results suggest that the cell population mobilized
after vascular trauma consists of VEGFR2+
cells expressing VE-cadherin and AC133.
|
BM-Derived CEPs Are Present in a Significant
Number of Mobilized PBMNCs
Emerging data suggest that late-outgrowth endothelial
cells differentiating from the nonadherent population of plated PBMNCs
represent a population of BM-derived anchorage-independent BM-derived
CEPs characterized by high proliferative potential.
To assess the number of mobilized PBMNCs with the
capacity of generating late-outgrowth colonies, PBMNCs mobilized from
burn and CABG patients 12 hours after trauma were grown in vitro in
conditions defined to support the formation of late-outgrowth
colonies.8 Typical
endothelial colonies, with cobblestone morphology, appeared after 7 to
10 days of culture
(Figures 5A and 5B) and showed both the metabolic
incorporation of DiI-Ac-LDL as well as vWF staining
(Figure 5C). These were the early-outgrowth endothelial
colonies, which are presumably derived form mature fallout circulating
ECs. Few endothelial colonies formed between 10 and 14 days of culture
(Figures 5A and 5B) and were positive for both DiI-Ac-LDL and
vWF
(Figure 5C). These were also scored as the early outgrowths.
On day 15, the nonadherent population was passed for a third time. The
colonies formed between 6 and 8 weeks
(Figures 5A and 5B) from this passaged nonadherent population
were referred to as the late-outgrowth endothelial colonies (CFU-ECs).
These late-outgrowth colonies were quantified based on their capacity
to metabolically incorporate DiI-Ac-LDL and stain positively with vWF
(Figure 5C). PBMNCs derived from control samples were able to
form the early outgrowths but not the late outgrowths. We and
others7 9 have
shown that purified populations of AC133 have the capacity to form
late-outgrowth colonies with a plating efficiency of 5%. On the basis
of these results, we estimated that close to 12% of the mobilized
AC133 cells were capable of forming late CFU-ECs. Collectively, these
data show that a small, but significant, number of the mobilized
circulating endothelial cells from burn and CABG patients, 12 hours
after trauma, were BM-derived CEPs.
|
Elevation of VEGF Plasma Levels in Mice
Resulted in Increased Number of Rapidly Mobilized
VEGFR2+CD11b-
PBMNCs
Intravenous administration of Ad vectors expressing
soluble VEGF165
(AdVEGF165) (1.5x108
pfu) induced a rapid (24 hour) mobilization of
VEGFR2+CD11b-
(14.7±0.57%) PBMNCs
(Figures 6A and 6B). CD11b/CD18 (Mac-1) is primarily expressed
on the myeloid-monocytic cells. In
AdVEGF165-inoculated mice, there was a maximum
increase in VEGF plasma levels at 24 hours
(Figure 7), which correlated with the number of rapidly
mobilized
VEGFR2+CD11b-
cells. VEGF levels gradually decreased over the next 2 weeks
(Figure 7). AdNull vector (no transgene), which was used as a
control, did not induce significant mobilization of
VEGFR2+CD11b-
(1.9±0.28%) cells
(Figures 6A and 6B). Circulating
VEGFR2+CD11b-
cells were still abundant (2.1±0.28%) in the
AdVEGF165-injected mice after 7 days compared
with control (AdNull-treated) mice (0.6±0.14%)
(Figure 6B). Doses above 1.5x108
pfu were toxic and resulted in the demise of the treated mice (data not
shown). There were no signs of toxicity in mice treated with AdNull
vectors at doses of up to 109 pfu. These
data suggest that elevation of VEGF plasma levels induce a rapid
mobilization of
VEGFR2+CD11b-
cells in mice within a similar time frame to that seen for the
mobilization of
VEGFR2+CD15-
cells in burn and CABG patients. Plasma VEGF levels remained low in
AdNull-injected mice
(Figure 7). These results suggest that, similar to burn or
CABG patients, an acute but transient increase in mouse plasma VEGF
levels promotes a rapid mobilization of
VEGFR2+CD11b-
cells into the peripheral circulation.
|
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Postnatal neovascularization is the process of new blood vessel formation from preexisting endothelial cells.10 However, the origin of endothelial cells incorporated into the newly formed blood vessels has been the subject of intensive scrutiny. Emerging data have suggested that a subpopulation of BM-derived CEPs may contribute to new blood vessel formation.5 11 12 13 It has been shown that CEPs have the capacity of being recruited into ischemic tissues or growing tumors.4 13 14 15 In the present study, we have extended these observations by demonstrating that vascular trauma induces a very rapid but transient mobilization of a significant number of BM-derived VEGFR2+AC133+ cells.
Given the rapid entry of the CEPs into the peripheral circulation, it has been suggested that the chemocytokines released as a result of the vascular injury may induce mobilization of CEPs. Among the known chemocytokines, VEGF has been shown to be effective in mobilizing CEPs into the peripheral circulation.3 Indeed, patients undergoing CABG or those who have suffered extensive burns, have elevated VEGF plasma levels, peaking 6 to 12 hours after vascular insult and gradually decreasing to baseline after 3 to 4 days. Elevated VEGF levels have also been measured in burn patients in a previous study.16 However, it remained unclear whether this increase in circulating VEGF levels had any physiological significance. In this report, we demonstrate that a rise in circulating VEGF levels is accompanied by an increase in PBMNCs comprised of a significant number of BM-derived CEPs. There was a 50-fold increase, compared with preoperative level, in the number of circulating cells 6 to 12 hours after surgery in CABG patients, and a similar result was seen in those patients suffering from extensive burns. Similarly, we demonstrate that acute elevation of plasma VEGF in vivo in mice leads to increased circulation of VEGFR2+ cells. Mice inoculated with adenoviral vectors encoding the VEGF165 transgene showed a rapid but transient increase in circulating VEGFR2+CD11b- PBMNCs. These data suggest that, similar to the murine VEGF-induced mobilization of CEPs, acute elevation of VEGF levels in vascular trauma patients may be the primary factor inducing mobilization of CEPs. However, because vascular trauma also promotes the release of numerous known or as-yet unrecognized chemocytokines, other factors in addition to VEGF may also contribute to the mobilization of CEPs.
Vascular trauma may also result in the nonspecific introduction of mature vascular wall–derived ECs into the circulation. We have used the expression pattern of AC133 and the potential of late-outgrowth CFU-EC colony formation to estimate the number of BM-derived CEPs. We demonstrate that, on average, close to 40% of the mobilized VEGFR2+ cells express AC133. In addition, we estimated that close to 12% of mobilized AC133+ cells form late-outgrowth CFU-ECs. Collectively, these data suggest that a small, but significant, number of the mobilized PBMNCs are BM-derived CEPs. It is intriguing that only the mobilized PBMNCs from earlier phases after the trauma were AC133+ or formed late-outgrowth colonies, suggesting that the rapid increase in circulating BM-derived CEPs is the result of a chemokinetic process, rather than differentiation or maturation of a population of stem cells. Furthermore, the rapid increase in PBMNCs with endothelial precursor potential suggests that the number of CEPs in the adult BM may be greater than expected. Taken together, these results suggest that the rapid mobilization of CEPs, in response to a rise in circulating VEGF levels after trauma, may contribute to the revascularization of the injured tissues.
Strategies to enhance mobilization and incorporation of CEPs into impaired vascular beds may have important therapeutic implications. However, it remains to be demonstrated to what extent these mobilized CEPs contribute to the compromised vascular tissue and whether acceleration of their mobilization and homing may promote the vascular healing process. Nevertheless, as shown in the present study, therapies aimed at blocking mobilization of CEPs and other BM-derived cells into the peripheral circulation and subsequently into neovascularized tissues may have undesirable clinical complications. Finally, VEGF-induced mobilization of VEGFR2+AC133+ cells may facilitate the isolation of an enriched population of CEPs from the peripheral circulation, which may ultimately be used for gene therapy or ex vivo expansion.
|
Acknowledgments |
|---|
S. Rafii is supported by National Heart, Lung, and Blood Institute (NHLBI) Grants R01 HL-58707, R01 HL-61849, P01-HL 66592 (project 2), an American Heart Association Grant-in-Aid, the Dorothy Rodbell Foundation for Sarcoma Research, and the Rich Foundation.
|
Footnotes |
|---|
Original received October 3, 2000; resubmission received November 16, 2000; revised resubmission received December 21, 2000; accepted December 21, 2000.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
1. Nissen NN, Polverini PJ, Koch AE, Volin MV, Gamelli RL, Di Pietro LA. Vascular endothelial growth factor mediates angiogenic activity during the proliferative phase of wound healing. Am J Pathol. 1998;152:1445–1452.[Abstract]
2.
Barleon B, Sozzani
S, Zhou D, Weich HA, Mantovani A, Marme D. Migration of human monocytes
in response to vascular endothelial growth factor (VEGF) is mediated
via the VEGF receptor flt-1.
Blood. 1996;87:3336–3343.
3. Asahara T, Takahashi T, Masuda H, Kalka C, Chen D, Iwaguro H, Inai Y, Silver M, Isner JM. VEGF contributes to postnatal neovascularization by mobilizing bone marrow-derived endothelial progenitor cells. EMBO J. 1999;18:3964–3972.[Medline] [Order article via Infotrieve]
4. Takahashi T, Kalka C, Masuda H, Chen D, Silver M, Kearney M, Magner M, Isner JM, Asahara T. Ischemia- and cytokine-induced mobilization of bone marrow-derived endothelial progenitor cells for neovascularization. Nat Med. 1999;5:434–438.[Medline] [Order article via Infotrieve]
5.
Shi Q, Rafii S, Wu
MH, Wijelath ES, Yu C, Ishida A, Fujita Y, Kothari S, Mohle R, Sauvage
LR, Moore MA, Storb RF, Hammond WP. Evidence for circulating bone
marrow-derived endothelial cells.
Blood. 1998;92:362–367.
6.
Rafii S, Oz MC,
Seldomridge JA, Ferris B, Asch AS, Nachman RL, Shapiro F, Rose EA,
Levin HR. Characterization of hematopoietic cells arising on the
textured surface of left ventricular assist devices.
Ann Thorac Surg. 1995;60:1627–1632.
7.
Peichev M, Naiyer
AJ, Pereira D, Zhu Z, Lane WJ, Williams M, Oz MC, Hicklin DJ, Witte L,
Moore MA, Rafii S. Expression of VEGFR-2 and AC133 by circulating human
CD34+ cells identifies a population of
functional endothelial precursors.
Blood. 2000;95:952–958.
8. Lin Y, Weisdorf DJ, Solovey A, Hebbel RP. Origins of circulating endothelial cells and endothelial outgrowth from. J Clin Invest. 2000;105:71–77.[Medline] [Order article via Infotrieve]
9.
Gehling UM, Ergun
S, Schumacher U, Wagener C, Pantel K, Otte M, Schuch G, Schafhausen P,
Mende T, Kilic N, Kluge K, Schafer B, Hossfeld DK, Fiedler W. In vitro
differentiation of endothelial cells from AC133-positive.
Blood. 2000;95:3106–3112.
10.
Folkman J, Shing
Y. Angiogenesis. J Biol
Chem. 1992;267:10931–10934.
11. Shi Q, Wu MH, Onuki Y, Ghali R, Hunter GC, Johansen KH, Sauvage LR. Endothelium on the flow surface of human aortic Dacron vascular grafts. J Vasc Surg. 1997;25:736–742.[Medline] [Order article via Infotrieve]
12.
Asahara T,
Murohara T, Sullivan A, Silver M, van der Zee R, Li T, Witzenbichler B,
Schatteman G, Isner JM. Isolation of putative progenitor endothelial
cells for angiogenesis.
Science. 1997;275:964–967.
13.
Asahara T, Masuda
H, Takahashi T, Kalka C, Pastore C, Silver M, Kearne M, Magner M, Isner
JM. Bone marrow origin of endothelial progenitor cells responsible for
postnatal vasculogenesis in physiological and pathological
neovascularization. Circ Res. 1999;85:221–228.
14.
Vale PR, Losordo
DW, Milliken CE, Maysky M, Esakof DD, Symes JF, Isner JM. Left
ventricular electromechanical mapping to assess efficacy of
phVEGF165 gene transfer for therapeutic
angiogenesis in chronic myocardial ischemia.
Circulation. 2000;102:965–974.
15.
Kalka C, Masuda
H, Takahashi T, Gordon R, Tepper O, Gravereaux E, Pieczek A, Iwaguro H,
Hayashi SI, Isner JM, Asahara T. Vascular endothelial growth
factor165 gene transfer augments circulating
endothelial progenitor cells in human subjects.
Circ Res. 2000;86:1198–1202.
16. Grad S, Ertel W, Keel M, Infanger M, Vonderschmitt DJ, Maly FE. Strongly enhanced serum levels of vascular endothelial growth factor. Clin Chem Lab Med. 1998;36:379–383.[Medline] [Order article via Infotrieve]
This article has been cited by other articles:
 |
|
 |
|
  U. Ravens Atrial fibrillation and circulating endothelial progenitor cells Europace, February 6, 2010; (2010) euq010v1. [Full Text] [PDF]
|
|
|
|
 |
|
 B. Wegiel, D. J. Gallo, K. G. Raman, J. M. Karlsson, B. Ozanich, B. Y. Chin, E. Tzeng, S. Ahmad, A. Ahmed, C. J. Baty, et al. Nitric Oxide-Dependent Bone Marrow Progenitor Mobilization by Carbon Monoxide Enhances Endothelial Repair After Vascular Injury Circulation, February 2, 2010; 121(4): 537 - 548. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Ueno, H. Koyama, S. Fukumoto, S. Tanaka, T. Shoji, T. Shoji, M. Emoto, H. Tahara, Y. Tsujimoto, T. Tabata, et al. Dialysis modality is independently associated with circulating endothelial progenitor cells in end-stage renal disease patients Nephrol. Dial. Transplant., February 1, 2010; 25(2): 581 - 586. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. H. Bahlmann, T. Speer, and D. Fliser Endothelial progenitor cells in chronic kidney disease Nephrol. Dial. Transplant., February 1, 2010; 25(2): 341 - 346. [Full Text] [PDF]
|
|
|
|
 |
|
 N L Mills, O Tura, G J Padfield, C Millar, N N Lang, D Stirling, C Ludlam, M L Turner, G R Barclay, and D E Newby Dissociation of phenotypic and functional endothelial progenitor cells in patients undergoing percutaneous coronary intervention Heart, December 15, 2009; 95(24): 2003 - 2008. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. D. Bhatwadekar, J. V. Glenn, T. M. Curtis, M. B. Grant, A. W. Stitt, and T. A. Gardiner Retinal Endothelial Cell Apoptosis Stimulates Recruitment of Endothelial Progenitor Cells Invest. Ophthalmol. Vis. Sci., October 1, 2009; 50(10): 4967 - 4973. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Lucchinetti, S. M. Zeisberger, I. Baruscotti, J. Wacker, J. Feng, K. Zaugg, R. Dubey, A. H. Zisch, and M. Zaugg Stem Cell-Like Human Endothelial Progenitors Show Enhanced Colony-Forming Capacity After Brief Sevoflurane Exposure: Preconditioning of Angiogenic Cells by Volatile Anesthetics Anesth. Analg., October 1, 2009; 109(4): 1117 - 1126. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 O. Dotsenko and M. Jahangiri Endogenous stem cells in patients undergoing coronary artery bypass graft surgery Eur. J. Cardiothorac. Surg., September 1, 2009; 36(3): 563 - 571. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Kim, H.-N. Pak, J. H. Park, J. I. Choi, M.-H. Nam, Y. Jo, and Y.-H. Kim Non-ischaemic titrated cardiac injury caused by radiofrequency catheter ablation of atrial fibrillation mobilizes CD34-positive mononuclear cells by non-stromal cell-derived factor-1{alpha} mechanism Europace, August 1, 2009; 11(8): 1024 - 1031. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B-C Lee, H-C Hsu, W-Y I Tseng, M-Y M Su, S-Y Chen, Y-W Wu, K-L Chien, and M-F Chen Effect of cardiac rehabilitation on angiogenic cytokines in postinfarction patients Heart, June 15, 2009; 95(12): 1012 - 1018. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Tian, P. H. Liang, and L.-Y. Li Inhibition of endothelial progenitor cell differentiation by VEGI Blood, May 21, 2009; 113(21): 5352 - 5360. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H E Thomas, P J Avery, J M Ahmed, R Edwards, I Purcell, A G Zaman, H M Arthur, and B D Keavney Local vessel injury following percutaneous coronary intervention does not promote early mobilisation of endothelial progenitor cells in the absence of myocardial necrosis Heart, April 1, 2009; 95(7): 555 - 558. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Nakamura, M. Kimura, C. Goto, K. Noma, M. Yoshizumi, K. Chayama, Y. Kihara, and Y. Higashi Cigarette Smoking Abolishes Ischemic Preconditioning-Induced Augmentation of Endothelium-Dependent Vasodilation Hypertension, April 1, 2009; 53(4): 674 - 681. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. S. Bonder, W. Y. Sun, T. Matthews, C. Cassano, X. Li, H. S. Ramshaw, S. M. Pitson, A. F. Lopez, P. T. Coates, R. L. Proia, et al. Sphingosine kinase regulates the rate of endothelial progenitor cell differentiation Blood, February 26, 2009; 113(9): 2108 - 2117. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Yamahara and H. Itoh Potential use of endothelial progenitor cells for regeneration of the vasculature Therapeutic Advances in Cardiovascular Disease, February 1, 2009; 3(1): 17 - 27. [Abstract] [PDF]
|
|
|
|
|
|
C. Conrad, H. Niess, R. Huss, S. Huber, I. von Luettichau, P. J. Nelson, H. C. Ott, K.-W. Jauch, and C. J. Bruns Multipotent Mesenchymal Stem Cells Acquire a Lymphendothelial Phenotype and Enhance Lymphatic Regeneration In Vivo Circulation, January 20, 2009; 119(2): 281 - 289. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Desai, A. Glaser, D. Liu, N. Raghavachari, A. Blum, G. Zalos, M. Lippincott, J. P. McCoy, P. J. Munson, M. A. Solomon, et al. Microarray-Based Characterization of a Colony Assay Used to Investigate Endothelial Progenitor Cells and Relevance to Endothelial Function in Humans Arterioscler Thromb Vasc Biol, January 1, 2009; 29(1): 121 - 127. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y.-S. Maeng, H.-J. Choi, J.-Y. Kwon, Y.-W. Park, K.-S. Choi, J.-K. Min, Y.-H. Kim, P.-G. Suh, K.-S. Kang, M.-H. Won, et al. Endothelial progenitor cell homing: prominent role of the IGF2-IGF2R-PLC{beta}2 axis Blood, January 1, 2009; 113(1): 233 - 243. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M.-C. Kuo, D. Patschan, S. Patschan, L. Cohen-Gould, H.-C. Park, J. Ni, F. Addabbo, and M. S. Goligorsky Ischemia-Induced Exocytosis of Weibel-Palade Bodies Mobilizes Stem Cells J. Am. Soc. Nephrol., December 1, 2008; 19(12): 2321 - 2330. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Murasawa and T. Asahara Review: Cardiogenic potential of endothelial progenitor cells Therapeutic Advances in Cardiovascular Disease, October 1, 2008; 2(5): 341 - 348. [Abstract] [PDF]
|
|
|
|
 |
|
 J. Grisar, C. W. Steiner, M. Bonelli, T. Karonitsch, I. Schwarzinger, G. Weigel, G. Steiner, and J. S. Smolen Systemic lupus erythematosus patients exhibit functional deficiencies of endothelial progenitor cells Rheumatology, October 1, 2008; 47(10): 1476 - 1483. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. S. Arbab, B. Janic, R. A. Knight, S. A. Anderson, E. Pawelczyk, A. M. Rad, E. J. Read, S. D. Pandit, and J. A. Frank Detection of migration of locally implanted AC133+ stem cells by cellular magnetic resonance imaging with histological findings FASEB J, September 1, 2008; 22(9): 3234 - 3246. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Suriano, D. Chaudhuri, R. S. Johnson, E. Lambers, B. T. Ashok, R. Kishore, and R. K. Tiwari 17{beta}-Estradiol Mobilizes Bone Marrow-Derived Endothelial Progenitor Cells to Tumors Cancer Res., August 1, 2008; 68(15): 6038 - 6042. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Thill, N. V. Strunnikova, M. J. Berna, N. Gordiyenko, K. Schmid, S. W. Cousins, D. J. S. Thompson, and K. G. Csaky Late Outgrowth Endothelial Progenitor Cells in Patients with Age-Related Macular Degeneration Invest. Ophthalmol. Vis. Sci., June 1, 2008; 49(6): 2696 - 2708. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Smart and P. R. Riley The Stem Cell Movement Circ. Res., May 23, 2008; 102(10): 1155 - 1168. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Chu, K.-H. Jung, S.-T. Lee, H.-K. Park, D.-I. Sinn, J.-M. Kim, D.-H. Kim, J.-H. Kim, S.-J. Kim, E.-C. Song, et al. Circulating Endothelial Progenitor Cells as a New Marker of Endothelial Dysfunction or Repair in Acute Stroke * Supplemental Methods Stroke, May 1, 2008; 39(5): 1441 - 1447. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. -T. Lee, K. Chu, K. -H. Jung, D. -H. Kim, E. -H. Kim, V. N. Choe, J. -H. Kim, W. -S. Im, L. Kang, J. -E. Park, et al. Decreased number and function of endothelial progenitor cells in patients with migraine Neurology, April 22, 2008; 70(17): 1510 - 1517. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Stein, G. Wessling, I. Deisenhofer, G. Busch, B. Steppich, H. Estner, B. Zrenner, C. Schmitt, S. Braun, A. Schomig, et al. Systemic inflammatory changes after pulmonary vein radiofrequency ablation do not alter stem cell mobilization Europace, April 1, 2008; 10(4): 444 - 449. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. E. Thomas, R. Redgrave, M. S. Cunnington, P. Avery, B. D. Keavney, and H. M. Arthur Circulating Endothelial Progenitor Cells Exhibit Diurnal Variation Arterioscler Thromb Vasc Biol, March 1, 2008; 28(3): e21 - e22. [Full Text] [PDF]
|
|
|
|
 |
|
 S. Brunner, H. D. Theiss, A. Murr, T. Negele, and W.-M. Franz Primary hyperparathyroidism is associated with increased circulating bone marrow-derived progenitor cells Am J Physiol Endocrinol Metab, December 1, 2007; 293(6): E1670 - E1675. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Diez, J. A. Barbera, E. Ferrer, R. Fernandez-Lloris, S. Pizarro, J. Roca, and V. I. Peinado Plasticity of CD133+ cells: Role in pulmonary vascular remodeling Cardiovasc Res, December 1, 2007; 76(3): 517 - 527. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Kanayasu-Toyoda, A. Ishii-Watabe, T. Suzuki, T. Oshizawa, and T. Yamaguchi A New Role of Thrombopoietin Enhancing ex Vivo Expansion of Endothelial Precursor Cells Derived from AC133-positive Cells J. Biol. Chem., November 16, 2007; 282(46): 33507 - 33514. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Roura, F. Planas, C. Prat-Vidal, R. Leta, C. Soler-Botija, F. Carreras, A. Llach, L. Hove-Madsen, G. P. Llado, J. Farre, et al. Idiopathic dilated cardiomyopathy exhibits defective vascularization and vessel formation Eur J Heart Fail, October 1, 2007; 9(10): 995 - 1002. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Michowitz, E. Goldstein, D. Wexler, D. Sheps, G. Keren, and J. George Circulating endothelial progenitor cells and clinical outcome in patients with congestive heart failure Heart, September 1, 2007; 93(9): 1046 - 1050. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Wang, Y. Zheng, W. Zhang, H. Yu, K. Lou, Y. Zhang, Q. Qin, B. Zhao, Y. Yang, and R. Hui Polymorphisms of KDR Gene Are Associated With Coronary Heart Disease J. Am. Coll. Cardiol., August 21, 2007; 50(8): 760 - 767. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. L.T. Ballard and J. M. Edelberg Stem Cells and the Regeneration of the Aging Cardiovascular System Circ. Res., April 27, 2007; 100(8): 1116 - 1127. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X.-X. Wang, F.-R. Zhang, Y.-P. Shang, J.-H. Zhu, X.-D. Xie, Q.-M. Tao, J.-H. Zhu, and J.-Z. Chen Transplantation of Autologous Endothelial Progenitor Cells May Be Beneficial in Patients With Idiopathic Pulmonary Arterial Hypertension: A Pilot Randomized Controlled Trial J. Am. Coll. Cardiol., April 10, 2007; 49(14): 1566 - 1571. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Igreja, M. Courinha, A. S. Cachaco, T. Pereira, J. Cabecadas, M. G. da Silva, and S. Dias Characterization and clinical relevance of circulating and biopsy-derived endothelial progenitor cells in lymphoma patients Haematologica, April 1, 2007; 92(4): 469 - 477. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Shantsila, T. Watson, and G. Y.H. Lip Endothelial Progenitor Cells in Cardiovascular Disorders J. Am. Coll. Cardiol., February 20, 2007; 49(7): 741 - 752. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Roberts, Q. Xiao, G. Weir, Q. Xu, and M. Jahangiri Endothelial Progenitor Cells are Mobilized After Cardiac Surgery Ann. Thorac. Surg., February 1, 2007; 83(2): 598 - 605. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. O Robb, N. L Mills, D. E Newby, and F. C Denison Endothelial progenitor cells in pregnancy Reproduction, January 1, 2007; 133(1): 1 - 9. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. C. Schatteman, M. Dunnwald, and C. Jiao Biology of bone marrow-derived endothelial cell precursors Am J Physiol Heart Circ Physiol, January 1, 2007; 292(1): H1 - H18. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Pirro, G. Schillaci, R. Paltriccia, F. Bagaglia, C. Menecali, M. R. Mannarino, M. Capanni, A. Velardi, and E. Mannarino Increased Ratio of CD31+/CD42- Microparticles to Endothelial Progenitors as a Novel Marker of Atherosclerosis in Hypercholesterolemia Arterioscler Thromb Vasc Biol, November 1, 2006; 26(11): 2530 - 2535. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. J. Capoccia, R. M. Shepherd, and D. C. Link G-CSF and AMD3100 mobilize monocytes into the blood that stimulate angiogenesis in vivo through a paracrine mechanism Blood, October 1, 2006; 108(7): 2438 - 2445. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Li, E. E. Sharpe, A. B. Maupin, A. A. Teleron, A. L. Pyle, P. Carmeliet, and P. P. Young VEGF and PlGF promote adult vasculogenesis by enhancing EPC recruitment and vessel formation at the site of tumor neovascularization FASEB J, July 1, 2006; 20(9): 1495 - 1497. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Atluri, G. P. Liao, C. M. Panlilio, V. M. Hsu, M. J. Leskowitz, K. J. Morine, J. E. Cohen, M. F. Berry, E. E. Suarez, D. A. Murphy, et al. Neovasculogenic therapy to augment perfusion and preserve viability in ischemic cardiomyopathy. Ann. Thorac. Surg., May 1, 2006; 81(5): 1728 - 1736. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Schomig, G. Busch, B. Steppich, D. Sepp, J. Kaufmann, A. Stein, A. Schomig, and I. Ott Interleukin-8 is associated with circulating CD133+ progenitor cells in acute myocardial infarction Eur. Heart J., May 1, 2006; 27(9): 1032 - 1037. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Post and J. Waltenberger ACE inhibitors and statins for bone marrow failure following myocardial infarction? Cardiovasc Res, April 1, 2006; 70(1): 1 - 2. [Full Text] [PDF]
|
|
|
|
|
|
T. Yoshioka, M. Takahashi, Y. Shiba, C. Suzuki, H. Morimoto, A. Izawa, H. Ise, and U. Ikeda Granulocyte colony-stimulating factor (G-CSF) accelerates reendothelialization and reduces neointimal formation after vascular injury in mice Cardiovasc Res, April 1, 2006; 70(1): 61 - 69. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. I. Peinado, J. Ramirez, J. Roca, R. Rodriguez-Roisin, and J. A. Barbera Identification of Vascular Progenitor Cells in Pulmonary Arteries of Patients with Chronic Obstructive Pulmonary Disease Am. J. Respir. Cell Mol. Biol., March 1, 2006; 34(3): 257 - 263. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Goette, K. Jentsch-Ullrich, M. Hammwohner, S. Trautmann, A. Franke, H. U. Klein, and A. Auricchio Cardiac uptake of progenitor cells in patients with moderate-to-severe left ventricular failure scheduled for cardiac resynchronization therapy. Europace, March 1, 2006; 8(3): 157 - 160. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Hess, L. Wirthlin, T. P. Craft, P. E. Herrbrich, S. A. Hohm, R. Lahey, W. C. Eades, M. H. Creer, and J. A. Nolta Selection based on CD133 and high aldehyde dehydrogenase activity isolates long-term reconstituting human hematopoietic stem cells Blood, March 1, 2006; 107(5): 2162 - 2169. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Langer, A. E. May, K. Daub, U. Heinzmann, P. Lang, M. Schumm, D. Vestweber, S. Massberg, T. Schonberger, I. Pfisterer, et al. Adherent Platelets Recruit and Induce Differentiation of Murine Embryonic Endothelial Progenitor Cells to Mature Endothelial Cells In Vitro Circ. Res., February 3, 2006; 98(2): e2 - e10. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Werner and G. Nickenig Influence of Cardiovascular Risk Factors on Endothelial Progenitor Cells: Limitations for Therapy? Arterioscler Thromb Vasc Biol, February 1, 2006; 26(2): 257 - 266. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Skowasch, S. Schrempf, N. Wernert, M. Steinmetz, A. Jabs, I. Tuleta, U. Welsch, C. J. Preusse, J. A. Likungu, A. Welz, et al. Cells of primarily extravalvular origin in degenerative aortic valves and bioprostheses Eur. Heart J., December 1, 2005; 26(23): 2576 - 2580. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Werner, S. Kosiol, T. Schiegl, P. Ahlers, K. Walenta, A. Link, M. Bohm, and G. Nickenig Circulating Endothelial Progenitor Cells and Cardiovascular Outcomes N. Engl. J. Med., September 8, 2005; 353(10): 999 - 1007. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Lenk, V. Adams, P. Lurz, S. Erbs, A. Linke, S. Gielen, A. Schmidt, D. Scheinert, G. Biamino, F. Emmrich, et al. Therapeutical potential of blood-derived progenitor cells in patients with peripheral arterial occlusive disease and critical limb ischaemia Eur. Heart J., September 2, 2005; 26(18): 1903 - 1909. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Ruel, E. J. Suuronen, J. Song, V. Kapila, D. Gunning, G. Waghray, F. D. Rubens, and T. G. Mesana Effects of off-pump versus on-pump coronary artery bypass grafting on function and viability of circulating endothelial progenitor cells J. Thorac. Cardiovasc. Surg., September 1, 2005; 130(3): 633 - 639. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Massa, V. Rosti, I. Ramajoli, R. Campanelli, A. Pecci, G. Viarengo, V. Meli, M. Marchetti, R. Hoffman, and G. Barosi Circulating CD34+, CD133+, and Vascular Endothelial Growth Factor Receptor 2-Positive Endothelial Progenitor Cells in Myelofibrosis With Myeloid Metaplasia J. Clin. Oncol., August 20, 2005; 23(24): 5688 - 5695. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H.-G. Kopp, S. T. Avecilla, A. T. Hooper, S. V. Shmelkov, C. A. Ramos, F. Zhang, and S. Rafii Tie2 activation contributes to hemangiogenic regeneration after myelosuppression Blood, July 15, 2005; 106(2): 505 - 513. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. M. Bauer, R. J. Bauer, and O. C. Velazquez Angiogenesis, Vasculogenesis, and Induction of Healing in Chronic Wounds Vascular and Endovascular Surgery, July 1, 2005; 39(4): 293 - 306. [Abstract] [PDF]
|
|
|
|
|
|
B. Guleng, K. Tateishi, M. Ohta, F. Kanai, A. Jazag, H. Ijichi, Y. Tanaka, M. Washida, K. Morikane, Y. Fukushima, et al. Blockade of the Stromal Cell-Derived Factor-1/CXCR4 Axis Attenuates In vivo Tumor Growth by Inhibiting Angiogenesis in a Vascular Endothelial Growth Factor-Independent Manner Cancer Res., July 1, 2005; 65(13): 5864 - 5871. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. J. Dzau, M. Gnecchi, A. S. Pachori, F. Morello, and L. G. Melo Therapeutic Potential of Endothelial Progenitor Cells in Cardiovascular Diseases Hypertension, July 1, 2005; 46(1): 7 - 18. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Loeffler, J. A. Kruger, and R. A. Reisfeld Immunostimulatory Effects of Low-Dose Cyclophosphamide Are Controlled by Inducible Nitric Oxide Synthase Cancer Res., June 15, 2005; 65(12): 5027 - 5030. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Nagaya, H. Mori, S. Murakami, K. Kangawa, and S. Kitamura Adrenomedullin: angiogenesis and gene therapy Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2005; 288(6): R1432 - R1437. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. K. Haider and M. Ashraf Bone marrow stem cell transplantation for cardiac repair Am J Physiol Heart Circ Physiol, June 1, 2005; 288(6): H2557 - H2567. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Madeddu Therapeutic angiogenesis and vasculogenesis for tissue regeneration Exp Physiol, May 1, 2005; 90(3): 315 - 326. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Voskas, N. Jones, P. Van Slyke, C. Sturk, W. Chang, A. Haninec, Y. O. Babichev, J. Tran, Z. Master, S. Chen, et al. A Cyclosporine-Sensitive Psoriasis-Like Disease Produced in Tie2 Transgenic Mice Am. J. Pathol., March 1, 2005; 166(3): 843 - 855. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Podar and K. C. Anderson The pathophysiologic role of VEGF in hematologic malignancies: therapeutic implications Blood, February 15, 2005; 105(4): 1383 - 1395. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Schatteman Are Circulating CD133+ Cells Biomarkers of Vascular Disease? Arterioscler Thromb Vasc Biol, February 1, 2005; 25(2): 270 - 271. [Full Text] [PDF]
|
|
|
|
|
|
J. Grisar, D. Aletaha, C. W. Steiner, T. Kapral, S. Steiner, D. Seidinger, G. Weigel, I. Schwarzinger, W. Wolozcszuk, G. Steiner, et al. Depletion of Endothelial Progenitor Cells in the Peripheral Blood of Patients With Rheumatoid Arthritis Circulation, January 18, 2005; 111(2): 204 - 211. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Sengupta, S. Caballero, R. N. Mames, A. M. Timmers, D. Saban, and M. B. Grant Preventing Stem Cell Incorporation into Choroidal Neovascularization by Targeting Homing and Attachment Factors Invest. Ophthalmol. Vis. Sci., January 1, 2005; 46(1): 343 - 348. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Massa, V. Rosti, M. Ferrario, R. Campanelli, I. Ramajoli, R. Rosso, G. M. De Ferrari, M. Ferlini, L. Goffredo, A. Bertoletti, et al. Increased circulating hematopoietic and endothelial progenitor cells in the early phase of acute myocardial infarction Blood, January 1, 2005; 105(1): 199 - 206. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M-H Gaugler A unifying system: does the vascular endothelium have a role to play in multi-organ failure following radiation exposure? Br. J. Radiol., January 1, 2005; Supplement 27(1): 100 - 105. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. De Falco, D. Porcelli, A. R. Torella, S. Straino, M. G. Iachininoto, A. Orlandi, S. Truffa, P. Biglioli, M. Napolitano, M. C. Capogrossi, et al. SDF-1 involvement in endothelial phenotype and ischemia-induced recruitment of bone marrow progenitor cells Blood, December 1, 2004; 104(12): 3472 - 3482. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. D. Abbott, Y. Huang, D. Liu, R. Hickey, D. S. Krause, and F. J. Giordano Stromal Cell-Derived Factor-1{alpha} Plays a Critical Role in Stem Cell Recruitment to the Heart After Myocardial Infarction but Is Not Sufficient to Induce Homing in the Absence of Injury Circulation, November 23, 2004; 110(21): 3300 - 3305. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Hristov, W. Erl, S. Linder, and P. C. Weber Apoptotic bodies from endothelial cells enhance the number and initiate the differentiation of human endothelial progenitor cells in vitro Blood, November 1, 2004; 104(9): 2761 - 2766. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Rajantie, M. Ilmonen, A. Alminaite, U. Ozerdem, K. Alitalo, and P. Salven Adult bone marrow-derived cells recruited during angiogenesis comprise precursors for periendothelial vascular mural cells Blood, October 1, 2004; 104(7): 2084 - 2086. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Valgimigli, G. M. Rigolin, A. Fucili, M. D. Porta, O. Soukhomovskaia, P. Malagutti, A. M. Bugli, L. Z. Bragotti, G. Francolini, E. Mauro, et al. CD34+ and Endothelial Progenitor Cells in Patients With Various Degrees of Congestive Heart Failure Circulation, September 7, 2004; 110(10): 1209 - 1212. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Asahara and A. Kawamoto Endothelial progenitor cells for postnatal vasculogenesis Am J Physiol Cell Physiol, September 1, 2004; 287(3): C572 - C579. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Urbich and S. Dimmeler Endothelial Progenitor Cells: Characterization and Role in Vascular Biology Circ. Res., August 20, 2004; 95(4): 343 - 353. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Kondo, M. Hayashi, K. Takeshita, Y. Numaguchi, K. Kobayashi, S. Iino, Y. Inden, and T. Murohara Smoking Cessation Rapidly Increases Circulating Progenitor Cells in Peripheral Blood in Chronic Smokers Arterioscler Thromb Vasc Biol, August 1, 2004; 24(8): 1442 - 1447. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J.-H. Choi, K. L. Kim, W. Huh, B. Kim, J. Byun, W. Suh, J. Sung, E.-S. Jeon, H.-Y. Oh, and D.-K. Kim Decreased Number and Impaired Angiogenic Function of Endothelial Progenitor Cells in Patients With Chronic Renal Failure Arterioscler Thromb Vasc Biol, July 1, 2004; 24(7): 1246 - 1252. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Rehman, J. Li, L. Parvathaneni, G. Karlsson, V. R. Panchal, C. J. Temm, J. Mahenthiran, and K. L. March Exercise acutely increases circulating endothelial progenitor cells and monocyte-/macrophage-derived angiogenic cells J. Am. Coll. Cardiol., June 16, 2004; 43(12): 2314 - 2318. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. W. Losordo and S. Dimmeler Therapeutic Angiogenesis and Vasculogenesis for Ischemic Disease: Part II: Cell-Based Therapies Circulation, June 8, 2004; 109(22): 2692 - 2697. [Full Text] [PDF]
|
|
|
|
|
|
S Francis Endothelial progenitor cells and coronary artery disease Heart, June 1, 2004; 90(6): 591 - 592. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. D. Galiano, O. M. Tepper, C. R. Pelo, K. A. Bhatt, M. Callaghan, N. Bastidas, S. Bunting, H. G. Steinmetz, and G. C. Gurtner Topical Vascular Endothelial Growth Factor Accelerates Diabetic Wound Healing through Increased Angiogenesis and by Mobilizing and Recruiting Bone Marrow-Derived Cells Am. J. Pathol., June 1, 2004; 164(6): 1935 - 1947. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. J. Rabelink, H. C. de Boer, E. J.P. de Koning, and A.-J. van Zonneveld Endothelial Progenitor Cells: More Than an Inflammatory Response? Arterioscler Thromb Vasc Biol, May 1, 2004; 24(5): 834 - 838. [Abstract] [Full Text]
|
|
|
|
|
|
J. Matsui, T. Wakabayashi, M. Asada, K. Yoshimatsu, and M. Okada Stem Cell Factor/c-kit Signaling Promotes the Survival, Migration, and Capillary Tube Formation of Human Umbilical Vein Endothelial Cells J. Biol. Chem., April 30, 2004; 279(18): 18600 - 18607. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. Adams, K. Lenk, A. Linke, D. Lenz, S. Erbs, M. Sandri, A. Tarnok, S. Gielen, F. Emmrich, G. Schuler, et al. Increase of Circulating Endothelial Progenitor Cells in Patients with Coronary Artery Disease After Exercise-Induced Ischemia Arterioscler Thromb Vasc Biol, April 1, 2004; 24(4): 684 - 690. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C.-H. Wang, N. Ciliberti, S.-H. Li, P. E. Szmitko, R. D. Weisel, P. W.M. Fedak, M. Al-Omran, W.-J. Cherng, R.-K. Li, W. L. Stanford, et al. Rosiglitazone Facilitates Angiogenic Progenitor Cell Differentiation Toward Endothelial Lineage: A New Paradigm in Glitazone Pleiotropy Circulation, March 23, 2004; 109(11): 1392 - 1400. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. V. Beerepoot, N. Mehra, J. S. P. Vermaat, B. A. Zonnenberg, M. F. G. B. Gebbink, and E. E. Voest Increased levels of viable circulating endothelial cells are an indicator of progressive disease in cancer patients Ann. Onc., January 1, 2004; 15(1): 139 - 145. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||