Quantum dots on cell imaging and safety issues

Author(s):  
Quan Xu ◽  
Jiajia Gao ◽  
Siyang Wang ◽  
Yi Wang ◽  
Dong Liu ◽  
...  

When quantum dots are used as fluorescent probes or drug tracers for in vivo imaging, the quantum dots in the blood will come into direct contact with vascular endothelial cells....

1996 ◽  
Vol 316 (3) ◽  
pp. 703-707 ◽  
Author(s):  
Ralf BIRKENHÄGER ◽  
Bernard SCHNEPPE ◽  
Wolfgang RÖCKL ◽  
Jörg WILTING ◽  
Herbert A. WEICH ◽  
...  

Vascular endothilial growth factor (VEGF) and placenta growth factor (PIGF) are members of a dimeric-growth-factor family with angiogenic properties. VEGF is a highly potent and specific mitogen for endothelial cells, playing a vital role in angiogenesis in vivo. The role of PIGF is less clear. We expressed the monomeric splice forms VEGF-165, VEGF-121, PIGF-1 and PlGF-2 as unfused genes in Escherichia coli using the pCYTEXP expression system. In vitro dimerization experiments revealed that both homo- and hetero-dimers can be formed from these monomeric proteins. The dimers were tested for their ability to promote capillary growth in vivo and stimulate DNA synthesis in cultured human vascular endothelial cells. Heterodimers comprising different VEGF splice forms, or combinations of VEGF/PlGF splice forms, showed mitogenic activity. The results demonstrate that four different heterodimeric growth factors are likely to have as yet uncharacterized functions in vivo.


1983 ◽  
Vol 60 (1) ◽  
pp. 89-102
Author(s):  
D de Bono ◽  
C. Green

The interactions between human or bovine vascular endothelial cells and fibroblast-like vascular intimal spindle-shaped cells have been studied in vitro, using species-specific antibodies to identify the different components in mixed cultures. Pure cultures of endothelial cells grow as uniform, nonoverlapping monolayers, but this growth pattern is lost after the addition of spindle cells, probably because the extracellular matrix secreted by the latter causes the endothelial cells to modify the way they are attached to the substrate. The result is a network of tubular aggregates of endothelial cells in a three-dimensional ‘polylayer’ of spindle-shaped cells. On the other hand, endothelial cells added to growth-inhibited cultures of spindle-shaped cells will grow in sheets over the surface of the culture. Human endothelial cells grown in contact with spindle-shaped cells have a reduced requirement for a brain-derived endothelial growth factor. The interactions of endothelial cells and other connective tissue cells in vitro may be relevant to the mechanisms of endothelial growth and blood vessel formation in vivo, and emphasize the potential importance of extracellular matrix in controlling endothelial cell behaviour.


2002 ◽  
Vol 87 (06) ◽  
pp. 1069-1074 ◽  
Author(s):  
Hiroyuki Matsuno ◽  
Mikio Hayashi ◽  
Koji Horibuchi ◽  
Kiyotaka Okada ◽  
Hideharu Fukao ◽  
...  

SummaryThe effect of monosodium[2-(6-hydroxynaphthalen-2-yl)-6-methylpyrimidin-4-yloxy]acetate dihydrate (JTV-926) on fibrinolysis was investigated in vitro and in vivo. JTV-926 released tissue-type plasminogen activator (t-PA) from human vascular endothelial cells in a dose-dependent manner. The thrombolytic effect of JTV-926 was studied using three animal thrombosis models; a photo-irradiation-induced mouse carotid artery thrombosis model, a photo-irradiation-induced rat femoral artery thrombosis model and a thrombin-induced rat venous thrombosis model. In the mouse thrombosis model, t-PA deficient mice (t-PA−/−mice) and their wild-type (t-PA+/+) were used. JTV-926 was injected as a bolus 30 min after the interruption of blood flow by an occlusion thrombi. Blood flow was continuously monitored for 180 min after intravenous administration of JTV-926 (1 mg/kg). Although the recanalization rate of the occluded artery was 37.5% in t-PA +/+ mice with the vehicle control, it increased to 75% in t-PA+/+ mice after JTV-926 administration. However, when JTV-926 was administrated in t-PA−/−mice, vascular recanalization was not observed in any arteries. In the photo-irradiation-induced rat femoral artery thrombosis model, intra-duodenal administration of JTV-926 induced thrombolysis. Moreover, in the thrombin-induced rat venous thrombosis model, the dose-dependent thrombolysis was also observed by oral administration of JTV-926. It was suggested that JTV-926 revealed a sufficient thrombolytic effect through the absorption from the intestine. Thus, a newly synthesized compound, JTV-926 induced t-PA release from vascular endothelial cells and effective thrombolysis in vivo.


Blood ◽  
2010 ◽  
Vol 115 (20) ◽  
pp. 4130-4137 ◽  
Author(s):  
Jinmin Gao ◽  
Lei Sun ◽  
Lihong Huo ◽  
Min Liu ◽  
Dengwen Li ◽  
...  

Cylindromatosis (CYLD) is a deubiquitinase that was initially identified as a tumor suppressor and has recently been implicated in diverse normal physiologic processes. In this study, we have investigated the involvement of CYLD in angiogenesis, the formation of new blood vessels from preexisting ones. We find that knockdown of CYLD expression significantly impairs angiogenesis in vitro in both matrigel-based tube formation assay and collagen-based 3-dimensional capillary sprouting assay. Disruption of CYLD also remarkably inhibits angiogenic response in vivo, as evidenced by diminished blood vessel growth into the angioreactors implanted in mice. Mechanistic studies show that CYLD regulates angiogenesis by mediating the spreading and migration of vascular endothelial cells. Silencing of CYLD dramatically decreases microtubule dynamics in endothelial cells and inhibits endothelial cell migration by blocking the polarization process. Furthermore, we identify Rac1 activation as an important factor contributing to the action of CYLD in regulating endothelial cell migration and angiogenesis. Our findings thus uncover a previously unrecognized role for CYLD in the angiogenic process and provide a novel mechanism for Rac1 activation during endothelial cell migration and angiogenesis.


2001 ◽  
Vol 173 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Itaru Nishizuka ◽  
Yasushi Ichikawa ◽  
Takashi Ishikawa ◽  
Masako Kamiyama ◽  
Satoshi Hasegawa ◽  
...  

2012 ◽  
Vol 26 (1) ◽  
pp. 95-109 ◽  
Author(s):  
Kazuhito Tawaramoto ◽  
Ko Kotani ◽  
Mitsuru Hashiramoto ◽  
Yukiko Kanda ◽  
Tomoki Nagare ◽  
...  

Abstract The phosphatidylinositol 3-kinase signaling pathway in vascular endothelial cells is important for systemic angiogenesis and glucose metabolism. In this study, we addressed the precise role of the 3-phosphoinositide-dependent protein kinase 1 (PDK1)-regulated signaling network in endothelial cells in vivo, using vascular endothelial PDK1 knockout (VEPDK1KO) mice. Surprisingly, VEPDK1KO mice manifested enhanced glucose tolerance and whole-body insulin sensitivity due to suppression of their hepatic glucose production with no change in either peripheral glucose disposal or even impaired vascular endothelial function at 6 months of age. When mice were fed a standard diet at 6 months of age and a high-fat diet at 3 months of age, hypertrophy of epididymal adipose tissues was inhibited, adiponectin mRNA was significantly increased, and mRNA of MCP1, leptin, and TNFα was decreased in the white adipose tissue of VEPDK1KO mice in comparison with controls. Consequently, both the circulating adiponectin levels and the activity of hepatic AMP-activated protein kinase were significantly increased, subsequently enhancing whole-body insulin sensitivity and energy expenditure with increased hepatic fatty acid oxidation in VEPDK1KO mice. These results provide the first in vivo evidence that lowered angiogenesis through the deletion of PDK1 signaling not only interferes with the growth of adipose tissue but also induces increased energy expenditure due to amelioration of the adipocytokine profile. This demonstrates an unexpected role of PDK1 signaling in endothelial cells on the maintenance of proper glucose homeostasis through the regulation of adipocyte development.


2015 ◽  
Vol 31 (2) ◽  
pp. 33-40 ◽  
Author(s):  
Hyosoo Kim ◽  
Keun Ho Yang ◽  
Hyunjin Cho ◽  
Geumhee Gwak ◽  
Sun Cheol Park ◽  
...  

Author(s):  
LeShana SaintJean ◽  
H.S. Baldwin

The endocardium represents a distinct population of endothelial cells that arises during the initiation of heart development. Endocardial cells can easily be distinguished from most of the other cardiac cell types. However, endocardial and vascular endothelial cells contain a similar genetic profile that limits the ability to study each group independently. Despite these limitations, tremendous progress has been made in identifying the different roles of endocardial cells throughout heart development. Initial studies focused on the origin of endocardial cells and their role in valvulogenesis, trabeculation, and formation of the ventricular and atrial septum. With the advancement of microscopy and the availability of endocardial specific reporter models (in vitro and in vivo) we have obtained more insight into the molecular, structural, and functional complexity of the endocardium. Additional studies have demonstrated how the endocardium is also involved in the development of coronary vessels within the compact myocardium and in heart regeneration.


1990 ◽  
Vol 4 (9) ◽  
pp. 2665-2670 ◽  
Author(s):  
Shelly C. Bernstein ◽  
Marek J. Skoskiewicz ◽  
Rosemary Jones ◽  
Warren M. Zapol ◽  
Paul S. Russell

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