scholarly journals Establishment of Tube Formation Assay of Bone Marrow-Derived Endothelial Progenitor Cells

2013 ◽  
Vol 19 (7) ◽  
pp. 533-535 ◽  
Author(s):  
Ji-Kuai Chen ◽  
Ya-Ping Deng ◽  
Guo-Jun Jiang ◽  
Yun-Zi Liu ◽  
Ting Zhao ◽  
...  
2013 ◽  
Vol 45 (21) ◽  
pp. 1021-1034 ◽  
Author(s):  
Brian R. Hoffmann ◽  
Jordan R. Wagner ◽  
Anthony R. Prisco ◽  
Agnieszka Janiak ◽  
Andrew S. Greene

Bone marrow-derived endothelial progenitor cells (BM-EPCs) are stimulated by vascular endothelial growth factor-A (VEGF-A) and other potent proangiogenic factors. During angiogenesis, an increase in VEGF-A expression stimulates BM-EPCs to enhance endothelial tube formation and contribute to an increase in microvessel density. Hypoxia is known to produce an enhanced angiogenic response and heightened levels of VEGF-A have been seen in oxygen deprived epithelial and endothelial cells, yet the pathways for VEGF-A signaling in BM-EPCs have not been described. This study explores the influence of hypoxia on VEGF-A signaling in rat BM-EPCs utilizing a novel proteomic strategy to directly identify interacting downstream components of the combined VEGF receptor(s) signaling pathways, gene expression analysis, and functional phenotyping. VEGF-A signaling network analysis following liquid chromatographic separation and tandem mass spectrometry revealed proteins related to inositol/calcium signaling, nitric oxide signaling, cell survival, cell migration, and inflammatory responses. Alterations in BM-EPC expression of common angiogenic genes and tube formation in response to VEGF-A during hypoxia were measured and combined with the proteomic analysis to enhance and support the signaling pathways detected. BM-EPC tube formation assays in response to VEGF-A exhibited little tube formation; however, a cell projection/migratory phenotype supported the signaling data. Additionally, a novel assay measuring BM-EPC incorporation into preformed endothelial cell tubes indicated a significant increase of incorporated BM-EPCs after pretreatment with VEGF-A during hypoxia. This study verifies known VEGF-A pathway components and reveals several unidentified mechanisms of VEGF-A signaling in BM-EPCs during hypoxia that may be important for migration to sites of vascular regeneration.


2021 ◽  
pp. 1-12
Author(s):  
Ling Chen ◽  
Luping Dai ◽  
Dewen Yan ◽  
Boya Zhou ◽  
Wei Zheng ◽  
...  

<b><i>Objective:</i></b> This study investigates the synergistic effects of Gleevec (imatinib) and rapamycin on the proliferative and angiogenic properties of mouse bone marrow-derived endothelial progenitor cells (EPCs). <b><i>Materials and Methods:</i></b> EPCs were isolated from mouse bone marrow and treated with different concentrations of Gleevec or rapamycin individually or in combination. The cell viability and proliferation were examined using the MTT assay. An analysis of cell cycle and apoptosis was performed using flow cytometry. Formation of capillary-like tubes was examined in vitro, and the protein expression of cell differentiation markers was determined using Western blot analysis. <b><i>Results:</i></b> Gleevec significantly reduced cell viability, cell proliferation, and induced cell apoptosis in EPCs. Rapamycin had similar effects on EPCs, but it did not induce cell apoptosis. The combination of Gleevec and rapamycin reduced the cell proliferation but increased cell apoptosis. Although rapamycin had no demonstratable effect on tube formation, the combined therapy of Gleevec and rapamycin significantly reduced tube formation when compared with Gleevec alone. Mechanistically, Gleevec, but not rapamycin, induced a significant elevation in caspase-3 activity in EPCs, and it attenuated the expression of the endothelial protein marker platelet-derived growth factor receptor α. Functionally, rapamycin, but not Gleevec, significantly enhanced the expression of endothelial differentiation marker proteins, while attenuating the expression of mammalian target of rapamycin signaling-related proteins. <b><i>Conclusions:</i></b> Gleevec and rapamycin synergistically suppress cell proliferation and tube formation of EPCs by inducing cell apoptosis and endothelial differentiation. Mechanistically, it is likely that rapamycin enhances the proapoptotic and antiangiogenic effects of Gleevec by promoting the endothelial differentiation of EPCs. Given that EPCs are involved in the pathogenesis of some cardiovascular diseases and critical to angiogenesis, pharmacological inhibition of EPC proliferation by combined Gleevec and rapamycin therapy may be a promising approach for suppressing cardiovascular disease pathologies associated with angiogenesis.


2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Charan T Gurrala ◽  
Venkata Garikipati ◽  
Zhongjian Cheng ◽  
Vandana Mallaredy ◽  
Maria Cimini ◽  
...  

Introduction: Estrogen or estrogen receptor-dependent mechanisms in enhancing the cardioprotective efficacy of bone marrow endothelial progenitor cells (BM-EPC) is well-established in preclinical studies. However, the efficacy of estrogen does not reflect in the data from randomized cardiovascular clinical trials, suggesting an estrogen-independent role of female BM-EPC in eliciting enhanced cardiac protection compared to males. Hypothesis: Epigenetic mechanisms may contribute to the sex-specific dimorphism of Sca-1 + /CD31 + BM-EPC in regulating cell-homing, pro-angiogenic and anti-inflammatory functions in the ischemic myocardium leading to enhanced reparative function of female progenitor cells. Methods & Results: Transplantation of GFP-BM-mononuclear cells from male and female GFP transgenic mice into the BM of lethally irradiated recipient male C57BL/6 mice resulted in the enhanced mobilization of female Sca-1 + CD31 + /GFP + BM-EPC into circulation post-MI. A higher number of female BM-EPC homed to the ischemic myocardium and significantly improved LV functions and capillary density post-MI compared to male BM-EPC. Female BM-EPC showed increased expression of bFGF, VEGFR2, SDF-1α, and IL-10 genes, thereby efficiently promoted endothelial tube formation in vitro compared to male BM-EPC. Transplantation of female BM-EPC and their exosomes into post-MI male mice improved LV cardiac function, reduced scar size, and improved capillary density compared to male BM-EPC and exosomes. Male BM-EPC showed an increased expression of G9a/Ehmt2, an H3K9me3 methyltransferase, and Dnmt3a DNA methyltransferase compared to female BM-EPC. In contrast, Kdm6b/JMJD3, H3K27me3 demethylase was highly expressed in female BM-EPC compared to males. Treatment of BM-EPC of both sexes with 17-β-estradiol did not alter the expression of Kdm6b/JMJD3. Male BM-EPC highly expressed repressive gene marks, H3K9me3, and H3K27me3 compared to females. Compared to the male, BM-EPC from female and ovariectomized (OXV) female mice showed equally high expression of angiogenic genes ANGPT-1, MDK, PLAU, Tie-2, and VEGFR2 and lower levels of inflammatory cytokines, TNFα, IFNγ, IL-1β, and CCL3. Conditioned medium from female and OVX BM-EPC equally promoted enhanced migration and tube formation of HUVEC in vitro, compared to male BM-EPC. Conclusions: An estrogen-independent epigenetic mechanism likely governs the enhanced cardiac reparative properties of female BM-EPC.


2009 ◽  
Vol 182 (4S) ◽  
pp. 1898-1905 ◽  
Author(s):  
Arun K. Sharma ◽  
Natalie J. Fuller ◽  
Ryan R. Sullivan ◽  
Noreen Fulton ◽  
Partha V. Hota ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Richard Longeras ◽  
Krysten Farjo ◽  
Michael Ihnat ◽  
Jian-Xing Ma

Proliferative diabetic retinopathy is characterized by pathological retinal neovascularization, mediated by both angiogenesis (involving mature endothelial cells) and vasculogenesis (involving bone marrow-derived circulating endothelial progenitor cells (EPCs)). Pigment epithelium-derived factor (PEDF) contains an N-terminal 34-amino acid peptide (PEDF-34) that has antiangiogenic properties. Herein, we present a novel finding that PEDF-34 also possesses antivasculogenic activity. In the oxygen-induced retinopathy (OIR) model using transgenic mice that have Tie2 promoter-driven GFP expression, we quantified Tie2GFP+cells in bone marrow and peripheral blood by fluorescence-activated cell sorting (FACS). OIR significantly increased the number of circulating Tie2-GFP+at P16, correlating with the peak progression of neovascularization. Daily intraperitoneal injections of PEDF-34 into OIR mice decreased the number of Tie2-GFP+cells in the circulation at P16 by 65% but did not affect the number of Tie2-GFP+cells in the bone marrow. These studies suggest that PEDF-34 attenuates EPC mobilization from the bone marrow into the blood circulation during retinal neovascularization.


2008 ◽  
Vol 215 (1) ◽  
pp. 234-242 ◽  
Author(s):  
Tomoyuki Matsumoto ◽  
Yutaka Mifune ◽  
Atsuhiko Kawamoto ◽  
Ryosuke Kuroda ◽  
Taro Shoji ◽  
...  

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