scholarly journals Role of mosquito saliva in blood vessel location

1984 ◽  
Vol 108 (1) ◽  
pp. 1-7 ◽  
Author(s):  
J. M. Ribeiro ◽  
P. A. Rossignol ◽  
A. Spielman
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Blood Feeding ◽  
Mosquito Saliva ◽  
Feeding Function ◽  
Aggregation Of Platelets ◽  
Biting Behaviour

In order to ascribe a blood feeding function to the saliva of mosquitoes, we determined whether this secretion may limit the initial probing phase of biting behaviour. The probing of hosts was indeed prolonged when the salivary ducts were severed, but this prolongation was absent when mosquitoes were fed on an artificial meal contained beneath a membrane. In vitro, turbidometric assays demonstrated that saliva inhibits the ADP- and collagen-mediated aggregation of platelets. ATP and ADP were hydrolysed by saliva, and this apyrase activity explains, in part, the observed effect upon platelets. We conclude that the saliva of mosquitoes functions by facilitating location of blood vessels.

Bioengineered in vitro Vascular Models for Applications in Interventional Radiology

2019 ◽  
Vol 24 (45) ◽  
pp. 5367-5374 ◽  
Author(s):  
Xiaoyun Li ◽  
Seyed M. Moosavi-Basri ◽  
Rahul Sheth ◽  
Xiaoying Wang ◽  
Yu S. Zhang
Keyword(s):  
Interventional Radiology ◽  
Animal Models ◽  
Blood Vessels ◽  
In Vitro Models ◽  
The Past ◽  
Endovascular Interventions ◽  
Conventional Animal ◽  
Vascular Structures

The role of endovascular interventions has progressed rapidly over the past several decades. While animal models have long-served as the mainstay for the advancement of this field, the use of in vitro models has become increasingly widely adopted with recent advances in engineering technologies. Here, we review the strategies, mainly including bioprinting and microfabrication, which allow for fabrication of biomimetic vascular models that will potentially serve to supplement the conventional animal models for convenient investigations of endovascular interventions. Besides normal blood vessels, those in diseased states, such as thrombosis, may also be modeled by integrating cues that simulate the microenvironment of vascular disorders. These novel engineering strategies for the development of biomimetic in vitro vascular structures will possibly enable unconventional means of studying complex endovascular intervention problems that are otherwise hard to address using existing models.

Abstract 237: PRMT1-p53-Slug Axis Regulates Epicardial EMT and Ventricular Development

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Olan Jackson-Weaver ◽  
Jian Wu ◽  
Yongchao Gou ◽  
Yibu Chen ◽  
Meng Li ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Heart Development ◽  
Cultured Cells ◽  
Migration And Invasion ◽  
P53 Expression ◽  
Epicardial Cells ◽  
Coronary Blood Vessels

Rationale: Epicardial epithelial-to-mesenchymal trasition (EMT) is a vital process in embryonic heart development. During EMT, epicardial cells acquire migratory and invasive properties, and differentiate into new cell types, including cardiac fibroblasts and coronary smooth muscle cells. Non-histone protein methylation is an emerging modulator of cell signaling. We have recently established a role for protein arginine methyltransferase-1 (PRMT1) in TGF-β-induced EMT in cultured cells. Objective: To determine the role of PRMT1 in epicardial EMT. Methods and Results: We investigated the role of PRMT1 in epicardial EMT in mouse epicardial cells. Embryonic day 9.5 (E9.5) tamoxifen administration of WT1-Cre ERT ;PRMT1 fl/fl ;ROSA-YFP fl/fl mouse embryos was used to delete PRMT1 in the epicardium. Epicardial PRMT1 deletion led to reduced epicardial migration into the myocardium, a thinner compact myocardial layer, and dilated coronary blood vessels at E15.5. Using the epicardial cell line MEC1, we found that PRMT1 siRNA prevented the increase in mesenchymal proteins Slug and Fibronectin and the decrease in epithelial protein E-Cadherin during TGF-β treatment-induced EMT. PRMT1 siRNA also reduced the migration and invasion of MEC1 cells. We further identified that PRMT1 siRNA also increased the expression of p53, a key regulator of the Slug degradation pathway. PRMT1 siRNA increases p53 expression by decreasing p53 degradation, and shifted p53 localization to the cytoplasm. In vitro methylation assays further demonstrated that PRMT1 methylates p53. Knockdown of p53 increased Slug levels and enhanced EMT, establishing p53 as a regulator of epicardial EMT through controlling Slug expression. Furthermore, RNAseq experiments in MEC1 cells demonstrated that 40% (545/1,351) of TGF-β-induced transcriptional changes were prevented by PRMT1 siRNA. Furthermore, when p53 and PRMT1 were simultaneously knocked down, TGF-β induced transcriptional control of 37% (201/545) of these PRMT1-dependent genes was restored. Conclusions: The PRMT1-p53-Slug pathway is necessary for epicardial EMT in cultured MEC1 cells as well as in the epicardium in vivo . Epicardial PRMT1 is required for the development of compact myocardium and coronary blood vessels.

Microfibrils (MF) Platelet Interaction: Requirement Of Von Willebrand Factor In Platelet Adhesion To A Placenta Microfibrillar Component (PMC)

1981 ◽  
Author(s):  
F Fauvel ◽  
Y J Legrand ◽  
N Gutman ◽  
J P Muh ◽  
G Tobelem ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Human Platelets ◽  
Human Artery ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Adhesion Of Platelets ◽  
Aggregation Of Platelets

It has been shown that collagenase resistant arterial microfibrils (MF) are able to interact with platelets and therefore represents, besides collagen, a second thrombogenic structure in the vessel wall. In vitro observation using a PMC purified from the villosities of human placenta by a mechanical non denaturing procedure confirm this interaction between platelets and MF. PMC was homogenous under electron microscope (feltwork of MF with a mean diameter of 120 – 130 A) and was glycoproteic in nature. PMC were able to induce an aggregation of human platelets only if the platelets were in plasma. The role of Von Willebrand factor (F VIII/WF) as a cofactor of the aggregation of platelets by MF has been postulated from the fact that twice washed platelets from normal subject resuspended in PPP obtained from a severe Von Willebrand deficient patient were not aggregated by the PMC. Furthermore, aggregation was restored after resuspension of the same platelets in the PPP of the same patient 30 and 120 minutes after perfusion of cryoprecipitate (40 units F VIII/RA per kg).F VIII/WF mediates platelet adhesion after binding to subendothelium of human artery. Our observation strongly supports the idea that MF are the subendothelial components to which F VIII/WF binds, thus promoting an adhesion of platelets.

scholarly journals Ontology groups representing angiogenesis and blood vessels development are highly up-regulated during porcine oviductal epithelial cells long-term real-time proliferation – a primary cell culture approach

2018 ◽  
Vol 6 (4) ◽  
pp. 186-194 ◽  
Author(s):  
Mariusz J. Nawrocki ◽  
Piotr Celichowski ◽  
Maurycy Jankowski ◽  
Wiesława Kranc ◽  
Artur Bryja ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Blood Vessel ◽  
Blood Vessels ◽  
Culture Conditions ◽  
Cellular Interactions ◽  
Biochemical Modification ◽  
Blood Vessel Development ◽  
Development Processes ◽  
Vessel Development

AbstractThe morphological and biochemical modification of oviductal epithelial cells (OECs) belongs to the group of compound processes responsible for proper oocyte transport and successful fertilization. The cellular interactions between cumulus-oocyte complexes (COCs) and oviductal epithelial cells (OECs) are crucial for this unique mechanism. In the present study we have analyzed angiogenesis and blood vessel development processes at transcript levels. By employing microarrays, four ontological groups associated with these mechanisms have been described. Differentially expressed genes belonging to the “angiogenesis”, “blood circulation”, “blood vessel development” and “blood vessel morphogenesis” GO BP terms were investigated as a potential markers for the creation of new blood vessels in cells under in vitro primary culture conditions.

The Role of Prostaglandins in the ADP-Induced Aggregation of Rabbit Platelets Shown by the Use of 15-Hydroxyprostaglandin Dehydrogenase

1978 ◽  
Vol 39 (03) ◽  
pp. 725-732 ◽  
Author(s):  
Robert B Wallis
Keyword(s):  
Platelet Rich Plasma ◽  
Shape Change ◽  
Rabbit Platelet ◽  
Direct Role ◽  
Initial Shape ◽  
Rabbit Platelets ◽  
Induced Aggregation ◽  
Aggregation Of Platelets

SummaryThe initial shape change and subsequent aggregation of platelets in citrated rabbit platelet-rich plasma caused by ADP in vitro was inhibited by 15-hydroxyprostaglandin dehydrogenase. This inhibition was NAD-dependent and was also seen when shape change and aggregation were initiated by sodium arachidonate or by collagen. The aggregation of gel-filtered rabbit platelets by thrombin was not, however, affected by removal of 15-hydroxyprostaglandins.Indomethacin was found to inhibit ADP-induced aggregation but at a concentration (250 μM) much higher than that required to inhibit collagen-induced aggregation. Moreover the platelet release reaction had not taken place 3 min after ADP stimulation. The direct role 15-hydroxyprostaglandin production in ADP-induced aggregation of rabbit platelets is proposed. The involvement of 15-hydroxyprostaglandins in platelet aggregation caused by other inducers is also discussed.

Artery-on-a-chip platform for automated, multimodal assessment of cerebral blood vessel structure and function

Lab on a Chip ◽  
2015 ◽  
Vol 15 (12) ◽  
pp. 2660-2669 ◽  
Author(s):  
Sanjesh Yasotharan ◽  
Sascha Pinto ◽  
John G. Sled ◽  
Steffen-Sebastian Bolz ◽  
Axel Günther
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Structure And Function ◽  
Microfluidic Platform ◽  
Cerebral Blood Vessel ◽  
Multimodal Assessment ◽  
Vessel Structure ◽  
And Function

We present a compact microfluidic platform for the automated, multimodal assessment of intact small blood vesselsin vitro.

Kallistatin is a new inhibitor of angiogenesis and tumor growth

Blood ◽  
2002 ◽  
Vol 100 (9) ◽  
pp. 3245-3252 ◽  
Author(s):  
Robert Q. Miao ◽  
Jun Agata ◽  
Lee Chao ◽  
Julie Chao
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Gene Delivery ◽  
Tumor Growth ◽  
Blood Vessels ◽  
Vascular Function ◽  
Hind Limb ◽  
Heparin Binding

Abstract Kallistatin is a unique serine proteinase inhibitor (serpin) and a heparin-binding protein. It has been localized in vascular smooth muscle cells and endothelial cells of human blood vessels, suggesting that kallistatin may be involved in the regulation of vascular function. Our previous study showed that kallistatin plays a role in neointima hyperplasia. In this study, we investigated the potential role of kallistatin in angiogenesis in vitro and in vivo. Purified human kallistatin significantly inhibited vascular endothelial growth factor (VEGF)– or basic fibroblast growth factor (bFGF)–induced proliferation, migration, and adhesion of cultured endothelial cells. Kallistatin attenuated VEGF- or bFGF-induced capillary density and hemoglobin content in subcutaneously implanted Matrigel plugs in mice. To further investigate the role of kallistatin in angiogenesis, we prepared adenovirus carrying the human kallistatin cDNA (Ad.HKBP) and evaluated the effect of kallistatin gene delivery on spontaneous angiogenesis in a rat model of hind-limb ischemia. Local kallistatin gene delivery significantly reduced capillary formation and regional blood perfusion recovery in the ischemic hind limb after removal of the femoral artery. Furthermore, a single intratumoral injection of Ad.HKBP into pre-established human breast tumor xenografts grown in athymic mice resulted in significant inhibition of tumor growth. CD31 immunostaining of tumor sections showed a decreased number of blood vessels in the kallistatin-treated group as compared to the control. These results demonstrate a novel role of kallistatin in the inhibition of angiogenesis and tumor growth.

VE-cadherin is not required for the formation of nascent blood vessels but acts to prevent their disassembly

Blood ◽  
2005 ◽  
Vol 105 (7) ◽  
pp. 2771-2776 ◽  
Author(s):  
Christopher V. Crosby ◽  
Paul A. Fleming ◽  
W. Scott Argraves ◽  
Monica Corada ◽  
Lucia Zanetta ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Cell Adhesion Molecule ◽  
De Novo ◽  
Temporal Correlation ◽  
Vascular Endothelial ◽  
Cell Clusters ◽  
Platelet Endothelial Cell Adhesion ◽  
Specific Step

Abstract We investigated the role of vascular endothelial (VE)–cadherin in blood vessel morphogenesis and established a temporal correlation linking the failure in vessel morphogenesis in VE-cadherin null embryos to a specific step in vasculogenesis. We showed that the sequence in which blood vessels failed followed the order in which they had formed (ie, those forming first—yolk sac, allantoic and endocardial vessels—were the first to display morphologic abnormalities). We next showed that in place of normal reticulated networks of blood vessels, clusters of platelet endothelial cell adhesion molecule–positive (PECAM+) cells formed within cultured allantois explants from VE-cadherin null embryos. Similarly, a function-blocking VE-cadherin antibody, BV13, caused PECAM+ cell clusters to form in cultured allantois explants from normal mice. Finally, we demonstrated that formation of PECAM+ cell clusters in response to BV13 was not due to a disruption in the formation of nascent vessels but was due to the actual disassembly of nascent vessels. Based on these findings, we conclude that the events of de novo blood vessel formation up to the point at which a vascular epithelium forms (ie, nascent vessels with lumens) are not dependent on VE-cadherin and that VE-cadherin, whose expression is up-regulated following vascular epithelialization, is required to prevent the disassembly of nascent blood vessels.

scholarly journals Silencing VEGFR-2 Hampers Odontoblastic Differentiation of Dental Pulp Stem Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Kajohnkiart Janebodin ◽  
Rakchanok Chavanachat ◽  
Aislinn Hays ◽  
Morayma Reyes Gil
Keyword(s):  
Stem Cells ◽  
Blood Vessels ◽  
Dental Pulp ◽  
Alizarin Red ◽  
Odontoblast Differentiation ◽  
Dentin Matrix ◽  
Dentin Regeneration

Dental pulp stem cells (DPSCs) are a source of postnatal stem cells essential for maintenance and regeneration of dentin and pulp tissues. Previous in vivo transplantation studies have shown that DPSCs are able to give rise to odontoblast-like cells, form dentin/pulp-like structures, and induce blood vessel formation. Importantly, dentin formation is closely associated to blood vessels. We have previously demonstrated that DPSC-induced angiogenesis is VEGFR-2-dependent. VEGFR-2 may play an important role in odontoblast differentiation of DPSCs, tooth formation and regeneration. Nevertheless, the role of VEGFR-2 signaling in odontoblast differentiation of DPSCs is still not well understood. Thus, in this study we aimed to determine the role of VEGFR-2 in odontoblast differentiation of DPSCs by knocking down the expression of VEGFR-2 in DPSCs and studying their odontoblast differentiation capacity in vitro and in vivo. Isolation and characterization of murine DPSCs was performed as previously described. DPSCs were induced by VEGFR-2 shRNA viral vectors transfection (MOI = 10:1) to silence the expression of VEGFR-2. The GFP+ expression in CopGFP DPSCs was used as a surrogate to measure the efficiency of transfection and verification that the viral vector does not affect the expression of VEGFR-2. The efficiency of viral transfection was shown by significant reduction in the levels of VEGFR-2 based on the Q-RT-PCR and immunofluorescence in VEGFR-2 knockdown DPSCs, compared to normal DPSCs. VEGFR-2 shRNA DPSCs expressed not only very low level of VEGFR-2, but also that of its ligand, VEGF-A, compared to CopGFP DPSCs in both transcriptional and translational levels. In vitro differentiation of DPSCs in osteo-odontogenic media supplemented with BMP-2 (100 ng/ml) for 21 days demonstrated that CopGFP DPSCs, but not VEGFR-2 shRNA DPSCs, were positive for alkaline phosphatase (ALP) staining and formed mineralized nodules demonstrated by positive Alizarin Red S staining. The expression levels of dentin matrix proteins, dentin matrix protein-1 (Dmp1), dentin sialoprotein (Dspp), and bone sialoprotein (Bsp), were also up-regulated in differentiated CopGFP DPSCs, compared to those in VEGFR-2 shRNA DPSCs, suggesting an impairment of odontoblast differentiation in VEGFR-2 shRNA DPSCs. In vivo subcutaneous transplantation of DPSCs with hydroxyapatite (HAp/TCP) for 5 weeks demonstrated that CopGFP DPSCs were able to differentiate into elongated and polarized odontoblast-like cells forming loose connective tissue resembling pulp-like structures with abundant blood vessels, as demonstrated by H&E, Alizarin Red S, and dentin matrix staining. On the other hand, in VEGFR-2 shRNA DPSC transplants, odontoblast-like cells were not observed. Collagen fibers were seen in replacement of dentin/pulp-like structures. These results indicate that VEGFR-2 may play an important role in dentin regeneration and highlight the potential of VEGFR-2 modulation to enhance dentin regeneration and tissue engineering as a promising clinical application.

scholarly journals Redistribution of surface anionic sites on the luminal front of blood vessel endothelium after interaction with polycationic ligand.

1976 ◽  
Vol 71 (1) ◽  
pp. 232-241 ◽  
Author(s):  
E Skutelsky ◽  
D Danon
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Binding Capacity ◽  
Luminal Surface ◽  
Lateral Migration ◽  
Anionic Sites ◽  
In Vitro Interaction ◽  
Anionic Groups

The ability of anionic groups on the luminal surface of blood vessels to redistribute by lateral migration under the influence of multivalent ligands was analyzed by electron microscopy, using cationized ferritin (CF). In vitro interaction of blood vessel segments with CF results in rapid aggregation of most anionic sites on the luminal fromt of the endothelium, followed by internalization or detachment of the CF patches, leaving most of the luminal surface devoid of anionic sites. Further incubation of such endothelial cells without CF results in regeneration of binding capacity for the polycationic label. Transport of CF, but not of native ferritin, across the endothelium by vesicle transport, followed by exocytosis of the interiorized CF clusters on the tissue front of the endothelium, was also observed. The possibility that such activities in the blood vessels in vivo may be associated with local changes in the normal distribution of the surface anionic sites as well as in accumulation of debris in the subendothelial layers of the vessels is suggested.

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