Umbilical Cord Blood CD133+ Stem Cells Exhibit Vasculogenic Capacity In Vitro and Augment Neovasculogenesis In Vivo in a Murine Model of Vascular Ischemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1790-1790
Author(s):  
M.R. Finney ◽  
L.R. Fanning ◽  
P.J. Vincent ◽  
D.G. Winter ◽  
M.A. Hoffman ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Blood Flow ◽  
Cord Blood ◽  
Umbilical Cord Blood ◽  
Hind Limb ◽  
Capillary Density ◽  
Functional Assays

Abstract Recent reports have utilized a variety of cell types for cellular therapy in mediating therapeutic angiogenesis in response to ischemia. We sought to assess the vasculogeneic potential of selected CD133+ hematopoietic stem cells (HSC) from umbilical cord blood (UCB) utilizing in vitro functional assays and an in vivo murine hind-limb ischemia model. Methods & Results: Mononuclear cells (MNC) from UCB or bone marrow (BM) were incubated with CD133+ conjugated magnetic beads, followed by automated sorting through magnetic columns (Miltenyi). Routine yield of CD133+ cells was 0.5±0.2% of UCB MNC and 0.7±0.3% of BM MNC, with a purity of 79±2% (UCB, n=30) and 84±5% (BM, n=12). Surface expression in the UCB CD133+ population was 3.6±1.5% KDR(VEGFR2), 8.7± 3.8% CXCR4 and 22.7±2.8% CD105 compared to 9.2±1.8% KDR, 14.4±1.3% CXCR4 and 23.7±2.3% CD105 in the BM CD133+ population. We measured chemotactic migration of cells towards SDF-1 (100ng/mL) compared to control wells containing media alone. The fold increase over control was 4.9±2.9 UCB MNC, 1.8±0.7 UCB CD133+ and 8.3±1.7 BM CD133+ (n=3). Angiogenic protein assays of CD133+ cells demonstrated elevated levels of IL-8 production as compared to MNC (103+/−380 pg/mL greater in CD133+ than MNC from the same UCB unit) when cultured for 24h in basal media. NOD/SCID mice underwent ligation of the right femoral artery and were given cells or vehicle control via intracardiac injection immediately following injury. Mice were given 1 x 106 MNC or 0.5 x 106 CD133+ cells. Laser Doppler flow measurements were obtained from both limbs each week for 6 weeks and the ratio of perfusion in the ischemic/healthy limb was calculated. At 28 days, perfusion ratios were statistically higher in study groups receiving UCB CD133+ cells, 0.55±0.06 (n=9), BM CD133+ cells 0.47±0.07 (n=8), BM MNC 0.48±0.8 (n=6) compared to cytokine controls 0.37±0.03 (n=12, p<0.05). Mice receiving UCB MNC did not show statistically significant improvement in measured blood flow over control animals 0.42±0.05 (n=8, p=0.34). At sacrifice, bone marrow was harvested to assess engraftment of human cells by flow cytometric analysis. Mice injected with UCB CD133+ cells showed 19±4.9% positive huCD45 cells compared to 2.5±0.6% for UCB MNC, 1.6±0.4% for BM CD133+ cells and 2.3±0.3% for BM MNC (n=3). Histological studies from day 42 tissue samples of muscle distal to arterial ligation were evaluated for capillary density. Control animals had capillary density of 131±6.9 cells/mm2. Capillary density was statistically higher that controls in animals receiving UCB CD133+ (320±18; p<0.0001), BM CD133++ (183±9.3; p<0.0001), and UCB MNC (164±10.5; p=0.011). Mice treated with BM MNC (135±9.4) did not have a statistically significant increase in capillary density from controls (p=0.73). In addition, animals treated with either UCB or BM-derived CD133+ cells had statistically higher capillary density than unselected MNC (p=<0.0001 and p=0.0004, respectively). Conclusions: In vitro functional assays showed that UCB-derived CD133+ HSC demonstrate enhanced homing capability (migration) as well as the potential for cellular recruitment (via IL-8 production) for angiogenesis in response to ischemia. Furthermore, UCB derived CD133+ HSC mediate significantly improved blood flow in an in vivo murine hind-limb injury model of ischemia, indicating the greater vasculogenic potential of selected CD133+ cells from of this stem cell source.

Outgrowing Endothelial Cells That Are Derived from Human Umbilical Cord Blood Improve Neovascularization in Hind-Limb Ischemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3697-3697
Author(s):  
Eun-Sun Yoo ◽  
KiHwan Kwon ◽  
Jee-Young Ahn ◽  
Soo-Ah Oh ◽  
Hye-Jung Chang ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cord Blood ◽  
Umbilical Cord Blood ◽  
Hind Limb ◽  
Limb Ischemia ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Hind Limb Ischemia

Abstract Backgroud: Human umbilical cord blood (UCB) contains a high number of endothelial progenitor cells (EPCs) and may be useful for the treatment of ischemic disease. Recently, we have isolated EPCs from UCB having different biologic properties for angiogenic capabilities in vitro. In this present study, the aim is to examine the usefulness of OECs in hind-limb ischemia. Methods: Mononuclear cells from UCB cultured using EGM-2 medium with VEGF, IGF-1 and FGF for 21 days. Early spindle-shaped cells (early OECs), which were grown during the first week of culture and late cobblestone shaped cells (late OECs), which were in peak growth during the third week of culture were found. The hind-limb ischemia was established as follows: Athymic nude mice (BALB/C-nu) 18–22 g in weight were anesthetized with pentobarbital (60 mg/kg) and their left femoral arteries and main extension arteries were operatively resected. To examine the effect of the vasculogenesis of the two types of OECs, the mice were divided into three groups (PBS, early and late OECs). Twenty-four hours after operative excision 5 × 105 OECs in 200 μl and an equal volume of PBS were administered by intramuscular injection into the mice on hind-limb ischemia. To compare the effect of OECs on neovascularization in vivo, the analysis of blood flow of ischemic and healthy hind limbs was performed on days 1 and 21 after surgery using near-infrared (NIR) imaging with incocyanne Green (ICG). Results: Late OECs expressed a high level of mRNA on endothelial marker genes and formed capillary tubes in Matrigel plates. The early spindle cells excreted more angiogenic cytokines and had more migratory ability. We divided the mice into two groups according to the degree of perfusion; good (22.5–50%/min) and poor (0–22.5%) perfusion. OECs improved the blood flow of the ischemic hind-limb in the ’good’ perfusion group but not in the ’poor’ perfusion group. Early OECs led to a more significant improvement in blood flow than that of the late OECs. Conclusion: The different types of OECs from UCB have different biologic properties in vitro and different vasculogenic potential in vivo as well. The results might have potential application for the treatment of hind-limb ischemia.

In Vitro Characterization of Umbilical Cord Blood CD133+ and In Vivo Functionality in Response to Ischemia in a Murine Hind-Limb Injury Model.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3693-3693
Author(s):  
Marcie R. Finney ◽  
Nicholas G. Greco ◽  
Matthew E. Joseph ◽  
Daniel G. Winter ◽  
Shyam Bhakta ◽  
...  
Keyword(s):  
Cord Blood ◽  
Umbilical Cord ◽  
Umbilical Cord Blood ◽  
Hind Limb ◽  
Study Groups ◽  
Chemotactic Migration ◽  
Limb Injury ◽  
Injury Model

Abstract Previous reports have demonstrated efficacy of cellular therapy in mediating therapeutic angiogenesis in response to ischemia. We sought to determine the potential efficacy of adult umbilical cord blood (UCB) derived selected CD133+ cells in the murine hind limb ischemia model and to characterize these cells by surface phenotype and functionality prior to injection. Methods and Results: Mononuclear cells (MNC) from UCB were labeled with CD133+ conjugated magnetic beads, followed by automated sorting through magnetic columns (Miltenyi). Routine yield of CD133+ cells was 0.51 ± 0.2% of MNC, with a purity of 78.7 ± 2.4% (n=30). Surface expression in the UCB CD133+ population was 3.59 ± 1.49% KDR(VEGFR2), 8.66 ± 3.79% CXCR4 and 22.74 ± 2.84% CD105 compared to 7.14 ± 2.15% KDR, 28.54 ± 5.81% CXCR4 and 6.74 ± 2.07% CD105 in the UCB MNC population. Transwell plates with 5μm collagen coated filters (Costar) were used to observe chemotactic migration of MNC or CD133+ cells towards SDF-1 (100ng/mL) compared to control wells containing media alone. Following a 3 hour incubation, the cells migrating to the bottom wells were counted by flow cytometry with TruCOUNT™ tubes (BD Biosciences). MNC and CD133+ cells migration to SDF showed a 4.9 ± 2.9 and 1.8 ± 0.7 fold increase over the negative control respectively. To test vasculogenic functionality of these selected cell populations, NOD/SCID mice underwent ligation of the right femoral artery and were randomized into 3 study groups: control (endothelial media with cytokines), non-selected MNC (1 x 106 cells/mouse) or CD133+ (0.5 x 106 cells/mouse) given via intracardiac injection immediately after injury. Doppler flow measurements were taken on both limbs each week for 4 weeks and the ratio of perfusion in the ischemic/healthy limb was calculated. At 28 days, perfusion ratios were statistically higher in study groups receiving CD133+ cells from UCB, 0.55 ± 0.07 (n=8) compared to cytokine controls 0.39 ± 0.02 (n=10, p=0.019). Mice receiving MNC did not show statistically significant improvement over control animals 0.42 ± 0.06 (n=7, p=0.27). Conclusion: Surface phenotyping was notable for increased expression of the receptor for SDF-1, CXCR4 on MNC when compared to CD133+ cells. In vitro functional assays showed that CD133+ and MNC exhibited increased chemotactic migration to SDF-1. In vivo studies showed that injection of UCB CD133+ cells improved blood flow compared with cytokines alone in the murine hind limb injury model, highlighting the vasculogenic potential of CD133+ cells from UCB.

Humanized Sc(Fv)2 Minibody against C-Mpl Successfully Increased Platelet Number in Monkey and Increased Engraftment of Human Umbilical Cord Blood Cells in NOD/SCID Mouse.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2322-2322
Author(s):  
Takashi Yoshikubo ◽  
Yoshihiro Matsumoto ◽  
Masahiko Nanami ◽  
Takayuki Sakurai ◽  
Hiroyuki Tsunoda ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cord Blood ◽  
Progenitor Cells ◽  
Umbilical Cord ◽  
Umbilical Cord Blood ◽  
Platelet Recovery ◽  
Cynomolgus Monkeys ◽  
Cd34 Cells

Abstract Thrombopoietin (TPO, the ligand for c-mpl) is a key factor for megakaryopoiesis. Several clinical trials of TPO have been conducted for thrombocytopenia without much success due to, in part, the production of neutralized antibodies against endogenous TPO, which causes thrombocytopenia. To overcome this problem, we previously demonstrated that mouse type minibody against c-mpl, with an amino acid sequence totally different from TPO, showed megakaryopoiesis and increased platelet numbers in monkey. This time, using CDR grafting, we generated a humanized sc(Fv)2VB22B minibody (huVB22B) against c-mpl for therapeutic use. The new minibody showed almost the same activity in vitro as TPO and the mouse type minibody, confirmed by both a human megakaryocyte cell (CD41+) differentiation assay and a proliferation assay with TPO-dependent cell line, M-07e. Single sc or iv administration of huVB22B to cynomolgus monkeys showed a dose-dependent increase in platelet numbers. Pharmacokinetic analysis showed that the plasma half-life (T1/2) of huVB22B at iv and sc administration to cynomolgus monkeys was 7–8 h and 11–16 h, respectively. After administration of huVB22B, the platelets of these monkeys increased and showed functional aggregation in response to ADP in vitro. Repeated administration of huVB22B (0.2, 2 and 20mg/kg/week) revealed that the increase in platelet level in cynomolgus monkeys was maintained for a month. Very slight reticular fibers in bone marrow were detected in a high dose group (20mg/ kg). No overt changes were detected by toxicity evaluations including clinical pathology and histopathology in 0.2 and 2mg/kg groups. No neutralized activities in plasma were observed during these experiments. Next, we examined the activities of huVB22B on human bone marrow-derived CD34-positive cells (BM-CD34+) and umbilical cord blood-derived CD34-positive cells (UCB-CD34+) in vitro. BM-CD34+ and UCB-CD34+ cells were cultured with huVB22B in serum free medium. HuVB22B induced differentiation of CD41+ cells from BM-CD34+ or UCB-CD34+ cells in a similar dose-dependent manner. However, UCB-CD34+ cells showed greater proliferation in response to huVB22B compared to BM-CD34+ cells. We then examined the in vivo activities of huVB22B on UCB CD34+ cells by treating NOD/SCID mice transplanted with human UCB-CD34+ cells with huVB22B and examining the bone marrow cells of the mice. The results showed that, compared with the control, administration of huVB22B showed an increase in the number of human hematopoietic progenitor cells (CD34+), lymphoid lineage cells (CD19+), and myeloid lineage cells (CD33+) in addition to human CFU-Meg cells (CD41+). These results suggest that c-mpl stimulation in vivo after transplantation might increase engraftment of progenitor cells in the bone marrow microenvironment and subsequently induce differentiation to multilineage cells. Umbilical cord blood transplantation faces frequent complications including a low-level stem/progenitor cell engraftment and delayed platelet recovery. Our results suggest that c-mpl stimulation might be used to increase the engraftment of UCB stem/progenitor cells and shorten the time of platelet recovery following UCB transplantation.

CD45−/ALDHlow/SSEA-4+/Oct-4+/CD133+/CXCR4+/Lin− Very Small Embryonic-Like (VSEL) Stem Cells Isolated from Umbilical Cord Blood as Potential Long Term Repopulating Hematopoietic Stem Cells

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2444-2444
Author(s):  
Ewa K Zuba-Surma ◽  
Magdalena Kucia ◽  
Rui Liu ◽  
Mariusz Z Ratajczak ◽  
Janina Ratajczak
Keyword(s):  
Stem Cells ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Umbilical Cord Blood ◽  
Mononuclear Cells ◽  
Hematopoietic Stem ◽  
Hematopoietic Activity

Abstract Recently, we identified a population of very small embryonic-like (VSEL) stem cells in umbilical cord blood (CB) (Leukemia2007;21:297–303) These VSELs are: smaller than erythrocytes; SSEA-4+/Oct-4+/CD133+/CXCR4+/Lin−/CD45−; responsive to SDF-1 gradient; and iv) possessing large nuclei that contain unorganized chromatin (euchromatin). Data obtained in a murine model indicate that a similar cell population isolated from bone marrow (BM) does not reveal hematopoietic activity after isolation. However, in appropriate models (i.e., in vitro co-culture over OP-9 cells or in vivo after intra bone injection), these cells contribute to hematopoiesis and thus possesses potential of long term repopulating hematopoietic stem cells (LT-HSCs). To investigate the hematopoietic activity of CB-derived, CD45 negative VSELs, we employed staining with Aldefluor detecting aldehyde dehydrogenase (ALDH), the enzyme expressed in primitive hematopoietic cells. We sorted CD133+/CD45−/ALDHhigh and CD133+/CD45−/ALDHlow sub-fractions of VSELs from CB samples and established that both freshly sorted CB-derived populations did not grow hematopoietic colonies in vitro. However, when activated/expanded over OP-9 stroma cells, they exhibit hematopoietic potential and initiate hematopoietic colonies composed of CD45+ cells when replated into methylcellulose cultures. Furthermore, while CD133+/CD45−/ALDHhigh VSELs gave raise to hematopoietic colonies after the first replating, the formation of colonies by CD133+/CD45−/ALDHlow VSELs was delayed. The data indicate that both populations of CD45− cells may acquire hematopoietic potential; however hematopoietic specification is delayed for CD133+/CD45−/ALDHlow cells (Fig. 1A). In parallel, real time PCR analysis revealed that freshly isolated CD133+/CD45−/ALDHhigh VSELs express more hematopoietic transcripts (e.g., c-myb, 80.2±27.4 fold difference) while CD133+/CD45−/ALDHlow exhibit higher levels of pluripotent stem cell markers (e.g., Oct-4, 119.5±15.5 fold difference) as compared to total CB mononuclear cells (Fig. B). Furthermore and somewhat unexpectedly, we found that because of their unusually small size, these important cells may be partially depleted (in 42.5±12.6%) during standard preparation strategies of CB units for storage that employ volume reduction. In conclusion, our data suggest very small CB mononuclear cells expressing VSEL markers that are CD133+/CD45−/ALDHlow are highly enriched for the most primitive population of LT-HSCs. These cells may be responsible for long term CB engraftment and be a population of cells from which HSCs should be expanded. We are currently testing this in an in vivo model by performing heterotransplants of CD45− ALDHlow VSELs into immunodeficient mice. It is important to stress that currently employed, routine CB processing strategies may lead up to ~50% loss of these small cells that are endowed with such remarkable hematopoietic activity. Figure Figure

In Vitro and In Vivo Evidence That Umbilical Cord Blood (UCB)-Derived CD45-/SSEA-4+/OCT-4+/CD133+/CXCR4+/Lin- Very Small Embryonic/Epiblast Like Stem Cells (VSELs) Do Not Contain Clonogenic Hematopoietic Progenitors but Are Highly Enriched in More Primitive Stem Cells - Novel View On Hierarchy of UCB Stem Cell Compartment.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 35-35 ◽  
Author(s):  
Ewa K. Zuba-Surma ◽  
Izabela Klich ◽  
Marcin Wysoczynski ◽  
Nicholas J Greco ◽  
Mary J. Laughlin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hematopoietic Stem Cells ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Umbilical Cord Blood ◽  
Hematopoietic Stem ◽  
Hematopoietic Activity

Abstract Abstract 35 Recently, we identified in umbilical cord blood (UCB) a population of very small embryonic/epiblast-like (VSEL) stem cells (Leukemia 2007;21:297–303) that are i) smaller than erythrocytes, ii) SSEA-4+/Oct-4+/CD133+/CXCR4+/Lin−/CD45−, iii) respond to SDF-1 gradient and iv) possess large nuclei containing primitive euchromatin. We have demonstrated in vitro that UCB-derived VSELs did not reveal hematopoietic activity freshly after isolation, but grow hematopoietic colonies following co-culture/activation over OP-9 cells. To investigate the hierarchy of UCB-derived, CD45 negative VSELs, we employed staining with Aldefluor - detecting aldehyde dehydrogenase (ALDH), the enzyme expressed in primitive hematopoietic cells. Subsequently, we sorted CD45−/CD133+/ALDHhigh and CD45−/CD133+/ALDHlow sub-fractions of VSELs from UCB samples and established that freshly sorted from UCB VSELs in contrast to sorted CD45+/ CD133+/ALDHhigh and CD45+/CD133+/ALDHlow hematopoietic stem cells (HSC) did not grow colonies in vitro. However, when CD45− VSELs were activated/expanded over OP-9 stroma cells, they exhibit hematopoietic potential and grew in routine methylcellulose cultures hematopoietic colonies composed of CD45+ cells. Interestingly, while CD45−/CD133+/ALDHhigh VSELs gave raise to hematopoietic colonies after the first replating, the formation of colonies by CD45−/CD133+/ALDHlow VSELs was somehow delayed, what suggest that they needed more time to acquire hematopoietic commitment. Thus our in vitro data indicate that both populations of CD45− cells may acquire hematopoietic potential; however hematopoietic specification is delayed for CD45−/CD133+/ALDHlow cells, suggesting their more primitive nature. In parallel, real time PCR analysis confirmed that while freshly isolated CD45−/CD133+/ALDHhigh VSELs express more hematopoietic transcripts (e.g., c-myb, 80.2±27.4 fold difference), CD45−/CD133+/ALDHlow exhibit higher levels of pluripotent stem cell markers (e.g., Oct-4, 119.5±15.5 fold difference as compared to total UCB mononuclear cells) (Figure 1 panel A). Next hematopoietic potential of UCB-derived VSELs was tested in vivo after transplantation into NOD/SCID mice (Figure 1 panel B and C). We noticed that both CD45−/CD133+/ALDHhigh and CD45−/CD133+/ALDHlow VSELs, give rise to human lympho-hematopoietic chimerism in lethally irradiated NOD/SCID mice as assayed 4–6 weeks after transplantation. The level of human hematopoietic CD45+ cells in murine peripheral blood (PB), bone marrow (BM) and spleen (SP) were comparable for both transplanted UCB-VSELs fractions - 7.1±2.9% (PB), 23.2±0.2% (SP) and 25.2±1.0% (BM). In conclusion, our data suggest that freshly isolated very small CD45 negative UCB-VSELs are depleted from clonogeneic progenitors, however they are highly enriched for primitive HSC. Based on our in vitro and in vivo data we postulate following hierarchy of hematopoietic stem cells in UCB (from most primitive to more differentiated) i) CD45−/CD133+/ALDHlow, ii) CD45−/CD133+/ALDHhigh , iii) CD45+/CD133+/ALDHlow and iv) CD45−/CD133+/ALDHhigh. We also postulate that as we have already shown for murine BM-derived VSELs, human UCB-derived CD45 negative VSELs correspond to a population of most primitive long term repopulating HSC (LT-HSC). Of note, we also found that currently employed, routine UCB processing strategies may lead up to ∼50% unwanted loss of these small cells that are endowed with such remarkable hematopoietic activity! Disclosures: No relevant conflicts of interest to declare.

Late Adherent Subpopulation in Umbilical Cord Blood Has the Same Characteristics and Hematopoiesis-Supporting Capacity As Mesenchymal Stromal/Stem Cells

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3384-3384
Author(s):  
Satoshi Yoshioka ◽  
Yasuo Miura ◽  
Masaki Iwasa ◽  
Aya Fujishiro ◽  
Noriko Sugino ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Umbilical Cord Blood ◽  
Research Funding ◽  
The Other ◽  
Adherent Cells ◽  
A Cell ◽  
Stromal Stem Cells

Abstract Mesenchymal stromal/stem cells (MSCs) are a major source of cell for cell therapy. MSCs derived from bone marrow (BMMSCs) have been mostly used in clinical applications. BMMSCs can be easily isolated as a cell population that adheres to plastic culture dishes within 1 week of culture. A recent report has demonstrated that cells that remain in suspension and fail to form adherent colonies contain a fraction of late adherent cells that resembles BMMSCs (Biomed Res Int, 2013; 2013: 790842). Umbilical cord blood (UCB) is as accessible as bone marrow for the isolation of MSCs. In this study, we identified a late adherent subpopulation in UCB and determined its hematopoiesis-supporting activity. Forty-five UCB units, which were not matched to the eligibility criterion defined in the Japan UCB donation program, were collected after delivery of placenta. Written informed consent was obtained before delivery from all pregnant women who participated in the study. The study protocol was approved by the ethics committee of the Kyoto University Graduate School of Medicine. Mononuclear cells were isolated from UCB by the density gradient centrifugation method with (n = 19) and without (n = 18) subsequent separation of CD34 negative cells using anti-CD34 immunomagnetic microbeads (Miltenyi Biotec, Bergisch Gladbach, Germany). Nucleated cells were separated by the hydroxyethyl starch sedimentation method from the other eight UCB units. The cells were then seeded into a culture flask and cultured in alpha minimal essential medium supplemented with 15% FBS (Culture 1; C1). After 1 week of culture, non-adherent cells in C1 supernatant were collected and re-seeded into a new flask (C2). The attached cells in C1 were cultured until adherent colonies emerged, after which they were detached using trypsin/EDTA and twice passaged to obtain a sufficient number of cells (C1 cells). In the same way, after 1 week of culture, non-adherent cells in C2 supernatant were collected and re-seeded into a new flask (C3). The attached cells in C2 were cultured to obtain C2 cells. Afterwards, re-seeding and culture (C4, C5c) were repeated until no new colonies were formed. Collected cells were cryopreserved and thawed when required in experiments. BMMSCs were isolated from human bone marrow cells purchased from AllCells (Emeryville, CA). C1 cells, the so-called UCBMSCs, were successfully isolated from 18 units (40 %). Adherent cells isolated from C2 and later were defined as elate adherent cellsf and, were obtained from 9 units: these cells were referred to as C2 cells (from 9 units), C3 cells (from 9 units), C4 cells (from 6 units) and C5 cells (from 2 units). The interval from seeding to the first colony formation in C1 was shorter in these 9 units than that in the other 9 units that contained only C1 cells: 10.8 } 1.4 vs 15.9 } 4.5 days, p < 0.01. The volume of the former 9 units tended to be large compared to the latter 9 units: 49.6 } 10.5 vs 33.7 } 21.0 mL, p = 0.07. These findings indicated that UCB containing late adherent cells was suitable for a cell source of MSCs. Next, we examined whether these late adherent cells (C2 and C3 cells) had properties consistent with those of MSCs. Both C2 and C3 cells showed spindle-shaped fibroblast-like morphology and the same immunophenotype as C1 cells: positive for CD73, CD90 and CD105, and negative for CD34, CD45 and HLA-DR. They had osteogenic, adipogenic and chondrogenic differentiation potentials in vitro. These findings are the minimal criteria for MSCs (Cytotherapy, 2006; 8:315). Finally, we evaluated the hematopoiesis-supporting activity of these cells in vitro and in vivo. CD45-positive hematopoietic cells were expanded when co-cultured of CD34-positive hematopoietic progenitor cells (6 ~ 102 cells) with C2 or C3 cells (2 ~ 104 cells) in vitro as much as when co-cultured with C1 cells (Figure A). In vivo analysis was conducted by using subcutaneous transplantation of MSCs on NOD/SCID mice (Int J Hematol, 2015; 102: 218). C2 cells induced trabecular bone formation and bone marrow hematopoiesis as well as C1 cells, however, C3 cells did not induce hematopoiesis (Figure B). In conclusion, we demonstrated that UCB contains a late adherent cell subpopulation with the same characteristics and hematopoiesis-supporting activity as those of UCBMSCs isolated using the conventional method. The continuance of cell culture without discarding suspension cells could improve the efficiency of isolation of MSCs from UCB. Disclosures Hirai: Kyowa Hakko Kirin: Research Funding; Novartis Pharma: Research Funding. Maekawa:Bristol-Myers K.K.: Research Funding.

Assessment of the Impact of Enforced Expression of Platelet Derived Growth Factor Beta in Human Mesenchymal Stem Cells and Contribution to Blood Flow Restoration.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3568-3568
Author(s):  
Claus Sondergaard ◽  
Fernando Antonio Fierro ◽  
Jeannine McGee ◽  
Jan A. Nolta
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Blood Flow ◽  
Mesenchymal Stem Cells ◽  
Hind Limb ◽  
Limb Ischemia ◽  
Platelet Derived Growth Factor ◽  
Growth Factor Beta ◽  
Ligation Site

Abstract Abstract 3568 Poster Board III-505 Both mesenchymal stem cells (MSC) and platelet derived growth factor beta (PDGFB) have been shown to promote angiogenesis in vivo and are therefore interesting therapeutic agents for the restoration of blood flow to ischemic tissues encountered in peripheral artery disease and critical limb ischemia. Careful evaluation of the mechanisms responsible for neovessel formation in stem cell-based therapeutic angiogenesis is critical for developing efficient treatment strategies. Previous studies have shown that MSCs correspond to pericytes, which are lost in PDGFB-null mice, suggesting that MSCs strongly rely on PDGFB signaling in vivo. Our major aim was to establish a highly sensitive method to assess whether overexpression of PDGFB in MSCs could modulate expression of pro-angiogenic cytokines and improve the restoration of bloodflow in an established murine xenograft model of hind limb ischemia. Human bone marrow derived MSCs (passage 2-5) were transduced with either a lentiviral vector containing the coding sequence of PDGFB or the same vector without PDGFB (control). As expected, overexpression of PDGFB strongly enhanced the proliferation of MSCs, reducing the doubling time from 51 to 20 hours (n=4, p<0.05). This effect correlated with a shift of 15% of cells from the G0/G1 to the S/G2/M phase, as compared to controls, when measured by flow cytometry of propidium iodide stained cells. Next, we induced a unilateral hind limb ischemia in NODSCIDbeta2null mice by excision of the femoral artery and performed intravenous transplantation of 2.5×10e5 MSCs (control MSC vs. PDGFB-MSC) the day following surgery. Recovery of blood flow to the affected limb was assessed at days 0 ((before transplantation), n=11), 4 (n=11), 7 (n=9), 10 (n=6), and 14 (n=6) by laser doppler imaging and values were normalized to the non-ischemic contralateral leg. Treated animals of both groups (control and PDGFB overexpressing MSC) exhibited a steadily progressive recovery in blood flow in the region proximal to the primary ligation site, reaching near normal levels by day 10. Surprisingly, no significant difference was seen in the blood flow recovery in animals receiving the PDGF over expressing MSCs. Donor MSCs (control and PDGFB) homed to the site of injury, as assessed by immunofluorescent staining of the ischemic muscle in the regions proximal and distal to the primary ligation site at days 4 and 7. However, the rapid recovery in blood flow did not appear to be attributed to a direct differentiation or integration of MSC into the vasculature, but rather through the expression of paracrine angiogenic factors. Interestingly, overexpression of PDGF reduced FGF2 mRNA expression levels in MSC (n=4, p=0.056), suggesting that high levels of PDGFB may indeed lead to a reduction of other key angiogenic factors, explaining the mild effect of PDGFB in vivo. Our results show that, although overexpression of PDGFB in bone marrow-derived MSCs enhanced the proliferation of MSC in vitro, it did not impact the speed or magnitude of blood flow recovery to the ischemic hind limb as compared to native MSCs, likely due to down modulation of other key angiogenic signals including FGF2. Disclosures: No relevant conflicts of interest to declare.

Novel Evidence for the Presence of Potent, Paracrine, Pro-Angiopoietic Effects of Purified Human Umbilical Cord Blood-Derived CD133+ Cells - Implications for Adult Stem Cell Therapies in Regenerative Medicine

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4740-4740
Author(s):  
Kasia Mierzejewska ◽  
Magdalena Kucia ◽  
Janina Ratajczak ◽  
Mariusz Z Ratajczak
Keyword(s):  
Stem Cells ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Umbilical Cord Blood ◽  
Adult Stem Cell ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Cell Therapies

Abstract Abstract 4740 Background. As populations of CD34+, CD34+CXCR4+, or CD133+ cells that are enriched in stem cells, adult stem and progenitor cells purified from bone marrow (BM), mobilized peripheral blood (mPB), and umbilical cord blood (UCB) are currently employed in the clinic to treat damaged organs (e.g., heart after myocardial infarction [AMI] or injured spinal cord or liver). The cell populations expressing these phenotypes are highly enriched primarily for hematopoietic stem/progenitor cells (HSPCs) and small numbers of endothelial progenitors, and for many years it has been wrongly supposed that they can trans-dedifferentiate into tissue-specific cells. However, even when improvement of organ function is observed after employing them in therapy, the lack of a convincing demonstration for the presence of donor-recipient chimerism in treated tissues in most of the studies performed so far indicates that mechanisms other than trans-dedifferentiation of the HSPCs delivered to the damaged organs into tissue-specific cells play a significant role in some positive clinical outcomes. In support of this conclusion, evidence has accumulated that stem cells secrete a variety of growth factors, cytokines, chemokines, and bioactive lipids that interact with the surrounding microenvironment and, when used in therapy, improve cell viability in damaged organs. In particular, more attention is currently being paid to microvesicles (MVs), which are shed from the cell surface or derived from the intracellular membrane compartment as mediators in cell-to-cell communication. Hypothesis. We hypothesized that these positive outcomes in adult stem cell therapies (e.g., by employing CD133+ cells) can be explained by the paracrine effects of these cells, involving both soluble factors as well as cell membrane-derived MVs. Experimental strategies. CD133+ cells were purified from UCB by employing immunomagnetic beads (> 95% purity as checked by FACS) and incubated for 24 hours in RPMI at 37°C in a small volume of medium supplemented with 0.5% albumin. Subsequently, we harvested conditioned media (CM) from these cells and isolated CD133+ cell-shed microvesicles (MVs) by high speed centrifugation. We employed sensitive ELISA assays to measure the concentration of important pro-angiopoietic and anti-apoptotic factors in CD133+ cell-derived CM and isolated mRNA from both CD133+ cells and CD133+ cell-derived MVs for RQ-PCR analysis of gene expression. Subsequently, the chemotactic activity of CD133+ cell-derived CM and MVs was tested against human umbilical cord blood endothelial cells (HUVECs), and, in parallel, we tested whether CD133+ cell-derived CM and MVs induce major signaling pathways in HUVECs. Finally, in in vitro functional assays, we tested the ability of CD133+ cell-derived CM and MVs to induce tube formation by HUVECs and the ability of in vivo Matrigel assay implants to induce angiogenesis. Results. We observed that highly purified UCB-derived CD133+ cells express mRNAs and secrete proteins for several pro-angiopoietic factors (e.g. VEGF, KL, FGF-2, and IGF-1) into CM and shed microvesicles (MVs) from the cell surface and endosomal compartment that are enriched for mRNAs encoding VEGF, KL, FGF-2, and IGF-1. Both CD133+ cell-derived CM and MVs possessed anti-apoptotic properties, increased the in vitro cell survival of endothelial cells, stimulated phosphorylation of MAPKp42/44 and AKT in HUVECs, induced chemotactic migration, proliferation and tube formation in vitro in HUVECs, as well as stimulated in vivo angiogenesis in Matrigel implants. Conclusions. These observations suggesting an important role for CD133+ cell-derived paracrine signals should be considered when evaluating clinical outcomes using purified CD133+ cells in regenerative medicine. Overall, these cell-derived paracrine signals may explain the therapeutic benefits of adult stem cells employed in regeneration of, for example, heart AMI. Finally, we will discuss several possibilities for enhancing secretion and modulating the composition of these paracrine signals that could be explored in the clinic. Disclosures: No relevant conflicts of interest to declare.

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