scholarly journals An in vitro Chondro-osteo-vascular Triphasic Model of the Osteochondral Complex

2020 ◽  
Author(s):  
Alessandro Pirosa ◽  
Riccardo Gottardi ◽  
Peter G. Alexander ◽  
Dario Puppi ◽  
Federica Chiellini ◽  
...  

AbstractThe generation of engineered models of the osteochondral complex to study its pathologies and develop possible treatments is hindered by the distinctly different properties of articular cartilage and subchondral bone, with the latter characterized by vascularization. In vitro models of the osteochondral complex have been mainly engineered as biphasic constructs containing just cartilage and bone cells, a condition very dissimilar from the in vivo environment. The different cellular components of the osteochondral complex are governed by interacting biochemical signaling; hence, to study the crosstalk among chondrocytes, osteoblasts, and endothelial cells, we have developed a novel triphasic model of the osteochondral tissue interface. Wet-spun poly(ε-caprolactone) (PCL) and PCL/hydroxyapatite (HA) scaffolds in combination with a methacrylated gelatin (gelMA) hydrogel were used as the polymeric backbone of the constructs. The scaffold components were engineered with human bone marrow derived mesenchymal stem cells (hMSCs) and human umbilical vein endothelial cells (HUVECs), and differentiated using a dual chamber microphysiological system (MPS) bioreactor that allows the simultaneous, separate flow of media of different compositions for induced differentiation of each compartment towards a cartilaginous or osseous lineage. Within the engineered Microphysiological Vascularized Osteochondral System (microVOCS), hMSCs showed spatially distinct chondrogenic and osteogenic markers in terms of histology and gene expression. HUVECs formed a stable capillary-like network in the engineered bone compartment and enhanced both chondrogenic and osteogenic differentiation of hMSCs, resulting in the generation of an in vitro system that mimics a vascularized osteochondral interface tissue.

Author(s):  
Susan Gallogly ◽  
Takeshi Fujisawa ◽  
John D. Hung ◽  
Mairi Brittan ◽  
Elizabeth M. Skinner ◽  
...  

Abstract Purpose Endothelial dysfunction is central to the pathogenesis of acute coronary syndrome. The study of diseased endothelium is very challenging due to inherent difficulties in isolating endothelial cells from the coronary vascular bed. We sought to isolate and characterise coronary endothelial cells from patients undergoing thrombectomy for myocardial infarction to develop a patient-specific in vitro model of endothelial dysfunction. Methods In a prospective cohort study, 49 patients underwent percutaneous coronary intervention with thrombus aspiration. Specimens were cultured, and coronary endothelial outgrowth (CEO) cells were isolated. CEO cells, endothelial cells isolated from peripheral blood, explanted coronary arteries, and umbilical veins were phenotyped and assessed functionally in vitro and in vivo. Results CEO cells were obtained from 27/37 (73%) atherothrombotic specimens and gave rise to cells with cobblestone morphology expressing CD146 (94 ± 6%), CD31 (87 ± 14%), and von Willebrand factor (100 ± 1%). Proliferation of CEO cells was impaired compared to both coronary artery and umbilical vein endothelial cells (population doubling time, 2.5 ± 1.0 versus 1.6 ± 0.3 and 1.2 ± 0.3 days, respectively). Cell migration was also reduced compared to umbilical vein endothelial cells (29 ± 20% versus 85±19%). Importantly, unlike control endothelial cells, dysfunctional CEO cells did not incorporate into new vessels or promote angiogenesis in vivo. Conclusions CEO cells can be reliably isolated and cultured from thrombectomy specimens in patients with acute coronary syndrome. Compared to controls, patient-derived coronary endothelial cells had impaired capacity to proliferate, migrate, and contribute to angiogenesis. CEO cells could be used to identify novel therapeutic targets to enhance endothelial function and prevent acute coronary syndromes.


RSC Advances ◽  
2019 ◽  
Vol 9 (40) ◽  
pp. 22921-22930 ◽  
Author(s):  
Kongpeng Lv ◽  
Qin Ren ◽  
Xingyan Zhang ◽  
Keda Zhang ◽  
Jia Fei ◽  
...  

Pro-angiogenic activity of astilbin on endothelial cells in vitro and zebrafish in vivo.


Blood ◽  
2003 ◽  
Vol 102 (1) ◽  
pp. 146-151 ◽  
Author(s):  
Arne Slungaard ◽  
Jose A. Fernandez ◽  
John H. Griffin ◽  
Nigel S. Key ◽  
Janel R. Long ◽  
...  

Abstract Platelet factor 4 (PF4), an abundant platelet α-granule protein, accelerates in vitro generation of activated protein C (APC) by soluble thrombin/thrombomodulin (TM) complexes up to 25-fold. To test the hypothesis that PF4 similarly stimulates endothelium-associated TM, we assessed the influence of human PF4 on thrombin-dependent APC generation by cultured endothelial monolayers. APC generated in the presence of 1 to 100 μg PF4 was up to 5-fold higher than baseline for human umbilical vein endothelial cells, 10-fold higher for microvascular endothelial cells, and unaltered for blood outgrowth endothelial cells. In an in vivo model, cynomolgus monkeys (n = 6, each serving as its own control) were infused with either PF4 (7.5 mg/kg) or vehicle buffer, then with human thrombin (1.0 μg/kg/min) for 10 minutes. Circulating APC levels (baseline 3 ng/mL) peaked at 10 minutes, when PF4-treated and vehicle-treated animals had APC levels of 67 ± 5 ng/mL and 39 ± 2 ng/mL, respectively (P < .001). The activated partial thromboplastin time (APTT; baseline, 28 seconds) increased maximally by 27 ± 6 seconds in PF4-treated animals and by 9 ± 1 seconds in control animals at 30 minutes (P < .001). PF4-dependent increases in circulating APC and APTT persisted more than 2-fold greater than that of control's from 10 through 120 minutes (P ≤ .04). All APTT prolongations were essentially reversed by monoclonal antibody C3, which blocks APC activity. Thus, physiologically relevant concentrations of PF4 stimulate thrombin-dependent APC generation both in vitro by cultured endothelial cells and in vivo in a primate thrombin infusion model. These findings suggest that PF4 may play a previously unsuspected physiologic role in enhancing APC generation. (Blood. 2003;102:146-151)


1994 ◽  
Vol 267 (3) ◽  
pp. H874-H879 ◽  
Author(s):  
A. Pietersma ◽  
N. De Jong ◽  
J. F. Koster ◽  
W. Sluiter

The objective of this study was to investigate the effect of hypoxia on the adhesiveness of endothelial cells for granulocytes. Human umbilical vein endothelial cells (HUVEC) were exposed to a PO2 of 7.5 mmHg (1.0 kPa), and the adherence of granulocytes was assessed under continuous hypoxia by means of a hypoxic incubator room. After 2 h of hypoxia the adherence of granulocytes decreased to 50% of the normoxic control, which was not due to a decreased viability of the endothelial cells nor to an increased generation of the antiadhesive factors nitric oxide, prostacyclin, and adenosine. Hypoxia also had no effect on the expression of intercellular adhesion molecule (ICAM)-1 or ICAM-2 on the endothelium. Although the mechanism of the action of hypoxia on the adhesiveness of endothelial cells remains unclear as yet, our data suggest that HUVEC possess a protective mechanism that prevents granulocyte adherence to endothelial cells under extreme hypoxic conditions. The decreased adherence seems paradoxical to the in vivo situation for which the increased margination of granulocytes within the vascular compartment of the ischemic tissue has been observed. However, hypoxia did not impair the potential adhesiveness of HUVEC, since stimulation of endothelial cells under hypoxic conditions with calcium ionophore or lipopolysaccharide increased the adherence of granulocytes in a similar fashion as under normoxic conditions. We therefore conclude that the increased margination of granulocytes during ischemia may be accomplished by the additional stimulation of hypoxic endothelial cells.


2004 ◽  
Vol 10 (24) ◽  
pp. 8250-8265 ◽  
Author(s):  
Florence Lefranc ◽  
Tatjana Mijatovic ◽  
Véronique Mathieu ◽  
Sandrine Rorive ◽  
Christine Decaestecker ◽  
...  

Author(s):  
Yuanyuan Li ◽  
Ying Shen ◽  
Yudan Zheng ◽  
Shundong Ji ◽  
Mengru Wang ◽  
...  

We previously demonstrated the immunostimulatory efficacy of Pseudomonas aeruginosa flagellar hook protein FlgE on epithelial cells, presumably via ectopic ATP synthases or subunits ATP5B on cell membranes. Here, by using recombinant wild-type FlgE, mutant FlgE (FlgEM; bearing mutations on two postulated critical epitopes B and F), and a FlgE analog in pull-down assay, Western blotting, flow cytometry, and ELISA, actual bindings of FlgE proteins or epitope B/F peptides with ATP5B were all confirmed. Upon treatment with FlgE proteins, human umbilical vein endothelial cells (HUVECs) and SV40-immortalized murine vascular endothelial cells manifested decreased proliferation, migration, tube formation, and surface ATP production and increased apoptosis. FlgE proteins increased the permeability of HUVEC monolayers to soluble large molecules like dextran as well as to neutrophils. Immunofluorescence showed that FlgE induced clustering and conjugation of F-actin in HUVECs. In Balb/c-nude mice bearing transplanted solid tumors, FlgE proteins induced a microvascular hyperpermeability in pinna, lungs, tumor mass, and abdominal cavity. All effects observed in FlgE proteins were partially or completely impaired in FlgEM proteins or blocked by pretreatment with anti-ATP5B antibodies. Upon coculture of bacteria with HUVECs, FlgE was detectable in the membrane and cytosol of HUVECs. It was concluded that FlgE posed a pathogenic ligand of ectopic ATP5B that, upon FlgE–ATP5B coupling on endothelial cells, modulated properties and increased permeability of endothelial layers both in vitro and in vivo. The FlgE-ectopic ATP5B duo might contribute to the pathogenesis of disorders associated with bacterial infection or ectopic ATP5B-positive cells.


Blood ◽  
2002 ◽  
Vol 99 (3) ◽  
pp. 912-922 ◽  
Author(s):  
Rainer Wiewrodt ◽  
Anu P. Thomas ◽  
Luca Cipelletti ◽  
Melpo Christofidou-Solomidou ◽  
David A. Weitz ◽  
...  

Abstract Cell-selective intracellular targeting is a key element of more specific and safe enzyme, toxin, and gene therapies. Endothelium poorly internalizes certain candidate carriers for vascular immunotargeting, such as antibodies to platelet endothelial cell adhesion molecule 1 (PECAM–1). Conjugation of poorly internalizable antibodies with streptavidin (SA) facilitates the intracellular uptake. Although both small and large (100-nm versus 1000-nm diameter) anti-PECAM/SA–beta galactosidase (SA–β-gal) conjugates bound selectively to PECAM-expressing cells, only small conjugates showed intracellular accumulation of active β-gal. To study whether size of the conjugates controls the uptake, a series of anti-PECAM/SA and anti-PECAM/bead conjugates ranging from 80 nm to 5 μm in diameter were produced. Human umbilical vein endothelial cells and PECAM-transfected mesothelioma cells internalized 80- to 350-nm anti-PECAM conjugates, but not conjugates larger than 500 nm. Further, size controls intracellular targeting of active therapeutic cargoes in vitro and in vivo. Small anti-PECAM/DNA conjugates transfected target cells in culture 5-fold more effectively than their large counterpart (350- versus 4200-nm diameter). To evaluate the practical significance of the size-controlled subcellular addressing, we coupled glucose oxidase (GOX) to anti-PECAM and antithrombomodulin. Both types of conjugates had equally high pulmonary uptake after intravenous injection in mice, yet only small (200- to 250-nm), not large (600- to 700-nm), GOX conjugates caused profound oxidative vascular injury in the lungs, presumably owing to intracellular generation of H2O2. Thus, engineering of affinity carriers of specific size permits intracellular delivery of active cargoes to endothelium in vitro and in vivo, a paradigm useful for the targeting of drugs, genes, and toxins.


2018 ◽  
Vol 32 (8) ◽  
pp. 1063-1070 ◽  
Author(s):  
Liancheng Xu ◽  
Yibing Guo ◽  
Yan Huang ◽  
Yicheng Xiong ◽  
Yang Xu ◽  
...  

Pancreas transplantation is considered as a promising therapeutic option with the potential to cure diabetes. However, efficacy of current clinical transplantation is limited by the donor organ. With regard to creating a functional pancreas-tissue equivalent for transplantation, vascularization remains a large obstacle. To enhance the angiogenic properties of pancreatic decellularized scaffold, surface modification of the vasculature was used to promote endothelialization efficiency. In this study, an endothelialized pancreatic decellularized scaffold was obtained through heparin modification under mild conditions. The immobilization of heparin was performed through 1-ethyl-3–(3-dimethylaminopropyl)-carbodiimide and N-Hydroxysuccinimide. The morphology, ultra-structure and porosity of the heparinized scaffold were characterized by toluidine blue staining, scanning electron microscope and infrared spectrum. The adhesion, proliferation and angiogenesis of human umbilical vein endothelial cells on heparin-pancreatic decellularized scaffold were also researched in vitro. In vivo transplantation was also performed to observe the location of human umbilical vein endothelial cells and the formation of new blood vessel, which exhibited significant differences with pancreatic decellularized scaffold group (p<0.05). These findings indicated that the endothelialized heparin-pancreatic decellularized scaffold may be used to solve the problem of blood supply and to support the function of insulin-secreting cells better after in vivo transplantation, and therefore, would be a potential candidate for pancreatic tissue engineering.


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