scholarly journals Novel Evidence That By Employing a Two-Step Differentiation Protocol in the Presence of UM171 and Nicotinamide Acid Human Very Small Embryonic like Stem Cells (VSELs) Differentiate into Functional Endothelial Cells (ECs)

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2070-2070
Author(s):  
Alison Domingues ◽  
Elisa Rossi ◽  
Kamila Bujko ◽  
Grégoire Detriche ◽  
Janina Ratajczak ◽  
...  

Abstract Background . Human Very small embryonic-like stem cells (VSELs) are CD133 + CD34 + small dormant stem cells with properties of self-renewal and multipotential ability to differentiate in the three-germ layers (Circulation Research 2019; 124: 208-210) and currently, more than 40 independent groups worldwide who have carefully followed the multicolor-staining cell-sorting strategy described by us (Current Protocols in Cytometry 2010 , 9.29.1-9.29.15). We have previously reported that human bone marrow (BM)-derived VSELs are able to give rise to vessel formation and endothelial differentiation (Thrombosis and Haemostasis 2015 ; 113 : 1084-1094) and several independent groups confirmed our data with human, mouse, or rat VSELs. Thus, VSELs are a promising source in regenerative medicine for the treatment of vascular diseases. Aim of the study. We aimed to develop an in vitro expansion and differentiation protocol of VSELs into endothelial cells (EC-VSELs) that will provide a clinically relevant cell therapy product without ethical problems and undesirable side effects. Materials and Methods. Highly purified by FACS from umbilical cord blood (UCB), VSELs were sorted as very small lineage-negative, CD45 -, CD34 + cells and then cultured and expanded into EC-VSELs in pro-angiogenic medium supplemented with mesodermal differentiation factors followed by stimulation by endothelial differentiation factors in the presence of UM171 and nicotinamide acid. In parallel, for comparison we expanded ECFCs from MNCs isolated from the same UCB units. The endothelial nature of the expanded VSEL-derived ECs (EC-VSELs) was tested by the expression of typical EC markers as well as by in vitro and in vivo functional angiogenic assays. Results. We report here for the first time a multistep differentiation strategy of highly purified UCB-derived VSELsThese cells after isolation by FACS were small and round, then in the presence of GSK3b inhibitor and BMP4 inducing mesodermal differentiation and high VEGF concentration to induce endothelial differentiation, VSELs enlarged and displayed extended morphology and acquired a characteristic cobblestone morphology. Finally, we have obtained a high number of cells with typical morphology of endothelial cells (EC-VSELs). By inhibiting potential mesodermal transition using TGFb inhibitor, EC-VSELs had a comparable morphology to primary human ECFCs and were characterized by tight junctions, caveolae, and Weibel-Palade Bodies, as demonstrated by transmission electron microscopy analysis of cell cultures conducted on fibrin network on the top of pericardial membranes. ECFCs differentiation was confirmed by analyzing the expression of endothelial markers by flow cytometry, and EC-VSELs were positive for PECAM1, VE-cadherin, VEGFR2, and endoglin. EC-VSELs as compared to ECFCs presented the same levels of expression of all these endothelial markers. What is important at the same time, EC-VSELs, as well as ECFCs, were negative for mesodermal marker Thy-1, confirming their endothelial phenotype. Migration properties of EC-VSELs were studied in basal conditions or in pro-angiogenic conditions using two in vitro models: wound healing assay and Trans well migration assay, and in both models EC-VSELs migration properties were similar to those of ECFCs. Next, we compared paracrine activity by evaluating growth factor and cytokine secretion profile of EC-VSELs, and noticed that the cytokine secretion by expanded VSELs was comparable to that of ECFCs. Moreover, the formation of pseudo-tubes was similar with both conditioned media. Finally, we have assessed the angiogenic capacity of EC-VSELs with a 3D in vitro sprouting assay and in vivo Matrigel plug assay. EC-VSELs display angiogenic properties but with lower potential in comparison with ECFCs which could be explained by their more primitive potential and most likely they need more time to be fully specified into the endothelial lineage. Conclusions. Based on our novel intriguing data, showing that highly purified VSELs expand efficient by employing a two-step differentiation protocol in the presence of UM171 and nicotinamide to EC-VSELs and acquire the same endothelial morphology, phenotype, and secretory potential as ECFCs as well as form functional vessels in in vitro and in vivo angiogenic assays, they could become an alternative source of ECFCs to treat vascular diseases. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4882-4882
Author(s):  
Alison Domingues ◽  
Kamila Bujko ◽  
Magdalena Kucia ◽  
Janina Ratajczak ◽  
Mariusz Z Ratajczak

Background . There is an ongoing search for multipotent stem cells from umbilical cord blood (UCB) with trans-germ layer differentiation potential that can be employed in repairing damaged organs and also expanded into transplantable hematopoietic stem cells (HSCs) and endothelial progenitor cells (EPCs). The existence of such cells in postnatal life could also revive the concept of hemangioblasts or hemangioblast-like cells in adult hematopoietic organs. Our group was the first to isolate a population of small CD34+CD133+lin-CD45- early-development stem cells from human hematopoietic tissues, including UCB. Based on the validated expression of early-development markers, these cells were named "very small embryonic-like stem cells" (VSELs, Circulation Res 2019; 124:208-210). Currently, more than 25 independent groups worldwide who have carefully followed the multicolor-staining cell-sorting strategy described by us (Current Protocols in Cytometry 2010, 9.29.1-9.29.15) have successfully isolated these cells and demonstrated their in vivo contribution to all three germ layer lineages. Thus, VSELs could be very useful in regenerative medicine in the field of angiogenesis, and UCB is an attractive source, with easy accessibility and tolerance to allogenic grafts. However, the low number of these cells in UCB and their quiescence are limiting factors. Therefore, in vitro differentiation of VSELs into endothelial progenitor cells (EPCs) would allow improvement in the ability to expand endothelial cells and could represent a clinically relevant alternative to embryonic stem cells (ESCs) and induced pluripotent stem cells (iPS) for cell therapy without ethical problems and undesirable side effects. Hypothesis. We hypothesized that UCB-purified, very small, early-developmentCD34+lin-CD45-stem cells can be ex vivo expanded into functional EPCs. Materials and Methods. VSELs highly purified by FACS were expanded into EPCs in pro-angiogenic medium supplemented with mesodermic differentiation factors and then endothelial differentiation factors in the presence of nicotinamide and UM171. In parallel, we expanded EPCs from MNCs isolated from the same UCB units by employing a classical protocol (Methods in Enzymology 2008, 445:303-29). The EPC nature of the expanded VSEL-derived cells was confirmed by the expression of typical EPC markers as well as by in vitro angiogenic assays. Results. Our differentiation cocktail allowed us to differentiate and expand VSELs into EPCs. In our expansion medium (Figure 1), the very small, round VSELs smaller than 6 mm in diameter proliferated and differentaited over time into larger and extended cells with a cobblestone morphology similar to the EPC control cells, and we confirmed their endothelial characteristics by cytometry analysis. Like EPCs, VSEL-derived EPCs were positive for CD31, CD144, KDR, and CD105 and negative for mesenchymal surface markers, such as CD90. They also performed similarly to EPCs in classical vasculogenic tests, including adhesion, proliferation, migration, and tubulogenesis assays. Conclusions. This work shows, for the first time, efficient VSEL differentiation into functional endothelial cells with vasculogenic properties without the help of co-culture over feeder-layers or viral vectors in medium supplemented with nicotinamide and UM171. These findings allow us to propose these cells as an interesting cell therapy product. These results also reopen the question of the existence of hemangioblast-like cells in postnatal tissues. We are currently testing these cells in vivo in model of hind limb ischemia. Figure 1 Disclosures No relevant conflicts of interest to declare.


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Sangho Lee ◽  
Min Kyung Lee ◽  
Hyunjoon Kong ◽  
Young-sup Yoon

Various hydrogels are used to create vascular structure in vitro or to improve cell engraftment to overcome low cell survival in vivo, a main hurdle for bare cell therapy Recently we developed a modified alginate hydrogel within which microchannels are aligned to guide the direction and spatial organization of loaded cells. We investigated whether these cell constructs in which HUVECs and human mesenchymal stem cells (hMSCs) are co-loaded in this novel microchanneled hydrogel facilitate formation of vessels in vitro and in vivo, and enhance recovery of hindlimb ischemia. We crafted a modified alginate hydrogel which has microchannels, incorporates a cell adhesion peptide RGD, and was encapsulated with VEGF. We then compared vascular structure formation between the HUVEC only (2 x 105 cells) group and the HUVEC plus hMSC group. In the HUVEC+hMSC group, we mixed HUVECs and hMSCs at the ratio of 3:1. For cell tracking, we labeled HUVECs with DiO, a green fluorescence dye. After loading cells into the microchannels of the hydrogel, these constructs were cultured for seven days and were examined by confocal microscopy. In the HUVEC only group, HUVECs stands as round shaped cells without forming tubular structures within the hydrogel. However, in the HUVEC+hMSC group, HUVECs were stretched out and connected with each other, and formed vessel-like structure following pre-designed microchannels. These results suggested that hMSCs play a critical role for vessel formation by HUVECs. We next determined their in vivo effects using a mouse hindlimb ischemia model. We found that engineered HUVEC+hMSC group showed significantly higher perfusion over 4 weeks compared to the engineered HUVEC only group or bare cell (HUVEC) group. Confocal microscopic analysis of harvested tissues showed more robust vessel formation within and outside of the cell constructs and longer term cell survival in HUVEC+hMSC group compared to the other groups. In conclusion, this novel microchanneled alginate hydrogel facilitates aligned vessel formation of endothelial cells when combined with MSCs. This vessel-embedded hydrogel constructs consisting of HUVECs and MSCs contribute to perfusable vessel formation, prolong cell survival in vivo, and are effective for recovering limb ischemia.


2019 ◽  
Vol 8 (11) ◽  
pp. 1782 ◽  
Author(s):  
Antonio Palladino ◽  
Isabella Mavaro ◽  
Carmela Pizzoleo ◽  
Elena De Felice ◽  
Carla Lucini ◽  
...  

Tissue engineering (TE) pursues the ambitious goal to heal damaged tissues. One of the most successful TE approaches relies on the use of scaffolds specifically designed and fabricated to promote tissue growth. During regeneration the guidance of biological events may be essential to sustain vasculature neoformation inside the engineered scaffold. In this context, one of the most effective strategies includes the incorporation of vasculature forming cells, namely endothelial cells (EC), into engineered constructs. However, the most common EC sources currently available, intended as primary cells, are affected by several limitations that make them inappropriate to personalized medicine. Human induced Pluripotent Stem Cells (hiPSC), since the time of their discovery, represent an unprecedented opportunity for regenerative medicine applications. Unfortunately, human induced Pluripotent Stem Cells-Endothelial Cells (hiPSC-ECs) still display significant safety issues. In this work, we reviewed the most effective protocols to induce pluripotency, to generate cells displaying the endothelial phenotype and to perform an efficient and safe cell selection. We also provide noteworthy examples of both in vitro and in vivo applications of hiPSC-ECs in order to highlight their ability to form functional blood vessels. In conclusion, we propose hiPSC-ECs as the preferred source of endothelial cells currently available in the field of personalized regenerative medicine.


2021 ◽  
Author(s):  
Qingjie Wang ◽  
Le Zhang ◽  
Zhiqin Sun ◽  
Boyu Chi ◽  
Ailin Zou ◽  
...  

Abstract Aims Naturally secreted extracellular vesicles (EVs) play important roles in stem-mediated cardioprotection. This study aimed to investigate the cardioprotective function and underlying mechanisms of EVs derived from HIF-1a engineered mesenchymal stem cells (MSCs) in a rat model of AMI.Methods and Results EVs isolated from HIF-1a engineered MSCs (HIF-1a-EVs) and control MSCs (MSCs-EVs) were prepared. In in vitro experiments, the EVs were incubated with cardiomyocytes and endothelial cells exposed to hypoxia and serum deprivation (H/SD); in in vivo experiments, the EVs were injected in the acutely infarcted hearts of Sprague-Dawley rats. Compared with MSCs-EVs, HIF-1a-EVs significantly inhibited the apoptosis of cardiomyocytes and enhanced angiogenesis of endothelial cells; meanwhile, HIF-1a-EVs also significantly shrunk fibrotic area and strengthened cardiac function in infarcted rats. After treatment with EVs/RGD-biotin hydrogels, we observed longer retention, higher stability in HIF-1a-EVs, and stronger cardiac function in the rats. Quantitative real-time PCR (qRT-PCR) displayed that miRNA-221-3p was highly expressed in HIF-1a-EVs. After miR-221-3p was inhibited in HIF-1a-EVs, the biological effects of HIF-1a EVs on apoptosis and angiogenesis were attenuated.Conclusion EVs released by MSCs with HIF-1a overexpression can promote the angiogenesis of endothelial cells and the apoptosis of cardiomyocytes via upregulating the expression of miR-221-3p. RGD hydrogels can enhance the therapeutic efficacy of HIF-1a engineered MSC-derived EVs.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ionela Movileanu ◽  
Marius Harpa ◽  
Hussam Al Hussein ◽  
Lucian Harceaga ◽  
Alexandru Chertes ◽  
...  

Introduction: Pediatric patients with cardiac congenital diseases require heart valve implants that can grow with their natural somatic increase in size. Current artificial valves perform poorly in children and cannot grow; thus, living-tissue-engineered valves capable of sustaining matrix homeostasis could overcome the current drawbacks of artificial prostheses and minimize the need for repeat surgeries.Materials and Methods: To prepare living-tissue-engineered valves, we produced completely acellular ovine pulmonary valves by perfusion. We then collected autologous adipose tissue, isolated stem cells, and differentiated them into fibroblasts and separately into endothelial cells. We seeded the fibroblasts in the cusp interstitium and onto the root adventitia and the endothelial cells inside the lumen, conditioned the living valves in dedicated pulmonary heart valve bioreactors, and pursued orthotopic implantation of autologous cell-seeded valves with 6 months follow-up. Unseeded valves served as controls.Results: Perfusion decellularization yielded acellular pulmonary valves that were stable, no degradable in vivo, cell friendly and biocompatible, had excellent hemodynamics, were not immunogenic or inflammatory, non thrombogenic, did not calcify in juvenile sheep, and served as substrates for cell repopulation. Autologous adipose-derived stem cells were easy to isolate and differentiate into fibroblasts and endothelial-like cells. Cell-seeded valves exhibited preserved viability after progressive bioreactor conditioning and functioned well in vivo for 6 months. At explantation, the implants and anastomoses were intact, and the valve root was well integrated into host tissues; valve leaflets were unchanged in size, non fibrotic, supple, and functional. Numerous cells positive for a-smooth muscle cell actin were found mostly in the sinus, base, and the fibrosa of the leaflets, and most surfaces were covered by endothelial cells, indicating a strong potential for repopulation of the scaffold.Conclusions: Tissue-engineered living valves can be generated in vitro using the approach described here. The technology is not trivial and can provide numerous challenges and opportunities, which are discussed in detail in this paper. Overall, we concluded that cell seeding did not negatively affect tissue-engineered heart valve (TEHV) performance as they exhibited as good hemodynamic performance as acellular valves in this model. Further understanding of cell fate after implantation and the timeline of repopulation of acellular scaffolds will help us evaluate the translational potential of this technology.


Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4265
Author(s):  
Huey-Shan Hung ◽  
Yi-Chin Yang ◽  
Wei-Chien Kao ◽  
Chun-An Yeh ◽  
Kai-Bo Chang ◽  
...  

Cardiovascular Diseases (CVDs) such as atherosclerosis, where inflammation occurs in the blood vessel wall, are one of the major causes of death worldwide. Mesenchymal Stem Cells (MSCs)-based treatment coupled with nanoparticles is considered to be a potential and promising therapeutic strategy for vascular regeneration. Thus, angiogenesis enhanced by nanoparticles is of critical concern. In this study, Polyethylene Glycol (PEG) incorporated with 43.5 ppm of gold (Au) nanoparticles was prepared for the evaluation of biological effects through in vitro and in vivo assessments. The physicochemical properties of PEG and PEG–Au nanocomposites were first characterized by UV-Vis spectrophotometry (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), and Atomic Force Microscopy (AFMs). Furthermore, the reactive oxygen species scavenger ability as well as the hydrophilic property of the nanocomposites were also investigated. Afterwards, the biocompatibility and biological functions of the PEG–Au nanocomposites were evaluated through in vitro assays. The thin coating of PEG containing 43.5 ppm of Au nanoparticles induced the least platelet and monocyte activation. Additionally, the cell behavior of MSCs on PEG–Au 43.5 ppm coating demonstrated better cell proliferation, low ROS generation, and enhancement of cell migration, as well as protein expression of the endothelialization marker CD31, which is associated with angiogenesis capacity. Furthermore, anti-inflammatory and endothelial differentiation ability were both evaluated through in vivo assessments. The evidence demonstrated that PEG–Au 43.5 ppm implantation inhibited capsule formation and facilitated the expression of CD31 in rat models. TUNEL assay also indicated that PEG–Au nanocomposites would not induce significant cell apoptosis. The above results elucidate that the surface modification of PEG–Au nanomaterials may enable them to serve as efficient tools for vascular regeneration grafts.


2021 ◽  
Vol 8 ◽  
Author(s):  
Crystal C. Kennedy ◽  
Erin E. Brown ◽  
Nadia O. Abutaleb ◽  
George A. Truskey

The vascular endothelium is present in all organs and blood vessels, facilitates the exchange of nutrients and waste throughout different organ systems in the body, and sets the tone for healthy vessel function. Mechanosensitive in nature, the endothelium responds to the magnitude and temporal waveform of shear stress in the vessels. Endothelial dysfunction can lead to atherosclerosis and other diseases. Modeling endothelial function and dysfunction in organ systems in vitro, such as the blood–brain barrier and tissue-engineered blood vessels, requires sourcing endothelial cells (ECs) for these biomedical engineering applications. It can be difficult to source primary, easily renewable ECs that possess the function or dysfunction in question. In contrast, human pluripotent stem cells (hPSCs) can be sourced from donors of interest and renewed almost indefinitely. In this review, we highlight how knowledge of vascular EC development in vivo is used to differentiate induced pluripotent stem cells (iPSC) into ECs. We then describe how iPSC-derived ECs are being used currently in in vitro models of organ function and disease and in vivo applications.


Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1614
Author(s):  
Paulina Podkalicka ◽  
Jacek Stępniewski ◽  
Olga Mucha ◽  
Neli Kachamakova-Trojanowska ◽  
Józef Dulak ◽  
...  

Inadequate supply of oxygen (O2) is a hallmark of many diseases, in particular those related to the cardiovascular system. On the other hand, tissue hypoxia is an important factor regulating (normal) embryogenesis and differentiation of stem cells at the early stages of embryonic development. In culture, hypoxic conditions may facilitate the derivation of embryonic stem cells (ESCs) and the generation of induced pluripotent stem cells (iPSCs), which may serve as a valuable tool for disease modeling. Endothelial cells (ECs), multifunctional components of vascular structures, may be obtained from iPSCs and subsequently used in various (hypoxia-related) disease models to investigate vascular dysfunctions. Although iPSC-ECs demonstrated functionality in vitro and in vivo, ongoing studies are conducted to increase the efficiency of differentiation and to establish the most productive protocols for the application of patient-derived cells in clinics. In this review, we highlight recent discoveries on the role of hypoxia in the derivation of ESCs and the generation of iPSCs. We also summarize the existing protocols of hypoxia-driven differentiation of iPSCs toward ECs and discuss their possible applications in disease modeling and treatment of hypoxia-related disorders.


2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Cong Li ◽  
Jinxian Huang ◽  
Huasu Zhu ◽  
Qing Shi ◽  
Dong Li ◽  
...  

Adipose-derived mesenchymal stem cells (A-MSCs) are promising cellular therapies for the treatment of immune-mediated diseases. Non-gene editing technologies can improve the immune regulatory function of A-MSCs. Our preliminary experiments revealed that an active form of vitamin B6—pyridoxal-5′-phosphate (PLP)—plays an important role in regulating gene expression and cytokine secretion in A-MSCs in vivo. To further clarify the effect of PLP on receptors and cytokines related to the immune regulatory function of A-MSCs, a series of experiments were designed to verify the relationships between PLP and A-MSCs in vitro. Initially, A-MSCs were obtained, and cytokine secretion and the expression of IDO1, NF-κB, and Toll-like receptors in PLP-stimulated A-MSCs were evaluated. In addition, coculture was used to detect A-MSCs-mediated apoptosis of CD3+CD8+ T lymphocytes. These results showed that A-MSCs stimulated with PLP were highly proliferative, consistent with their pluripotent capacity. Further, the surface receptors TLR3, TLR4, IDO1, and NF-κB were upregulated, while TLR6 was downregulated. Concurrently, A-MSCs preconditioned with PLP had the greatest inhibitory effect on CD3+CD8+ T lymphocyte proliferation, indicating that PLP altered the immune regulatory function of A-MSCs through the regulation of TLRs and IDO1 expression.


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