scholarly journals Mesenchymal stem cell-derived exosomes inhibit the VEGF-A expression in human retinal vascular endothelial cells induced by high glucose

2021 ◽  
Vol 14 (12) ◽  
pp. 1820-1827
Author(s):  
Guang-Hui He ◽  
◽  
Meng Dong ◽  
Song Chen ◽  
Yu-Chuan Wang ◽  
...  

AIM: To determine the effect of exosomes derived from human umbilical cord blood mesenchymal stem cells (hUCMSCs) on the expression of vascular endothelial growth factor A (VEGF-A) in human retinal vascular endothelial cells (HRECs). METHODS: Exosomes were isolated from hUCMSCs using cryogenic ultracentrifugation and characterized by transmission electron microscopy, Western blotting and nanoparticle tracking analysis. HRECs were randomly divided into a normal control group (group A), a high glucose model group (group B), a high glucose group with 25 μg/mL (group C), 50 μg/mL (group D), and 100 μg/mL exosomes (group E). Twenty-four hours after coculture, the cell proliferation rate was detected using flow cytometry, and the VEGF-A level was detected using immunofluorescence. After coculture 8, 16, and 24h, the expression levels of VEGF-A in each group were detected using PCR and Western blots. RESULTS: The characteristic morphology (membrane structured vesicles) and size (diameter between 50 and 200 nm) were observed under transmission electron microscopy. The average diameter of 122.7 nm was discovered by nanoparticle tracking analysis (NTA). The exosomal markers CD9, CD63, and HSP70 were strongly detected. The proliferation rate of the cells in group B increased after 24h of coculture. Immunofluorescence analyses revealed that the upregulation of VEGF-A expression in HRECs stimulated by high glucose could be downregulated by cocultured hUCMSC-derived exosomes (F=39.03, P<0.01). The upregulation of VEGF-A protein (group C: F=7.96; group D: F=17.29; group E: F=11.89; 8h: F=9.45; 16h: F=12.86; 24h: F=42.28, P<0.05) and mRNA (group C: F=4.137; group D: F=13.64; group E: F=22.19; 8h: F=7.253; 16h: F=16.98; 24h: F=22.62, P<0.05) in HRECs stimulated by high glucose was downregulated by cocultured hUCMSC-derived exosomes (P<0.05). CONCLUSION: hUCMSC-derived exosomes downregulate VEGF-A expression in HRECs stimulated by high glucose in time and concentration dependent manner.

2021 ◽  
Vol 271 ◽  
pp. 113855
Author(s):  
Junxiao Xi ◽  
Yuezhao Rong ◽  
Zifeng Zhao ◽  
Yihai Huang ◽  
Pu Wang ◽  
...  

1978 ◽  
Vol 15 (2) ◽  
pp. 186-195 ◽  
Author(s):  
T. Landsverk ◽  
H. Gamlem ◽  
R. Svenkerud

A generalized enlargement of the lymph nodes was found in an emaciated adult ewe. Additional autopsy findings included tiny grey-white necrotic foci in the heart muscle, aspiration pneumonia and diffuse pleuritis. Light microscopy showed a generalized lymphadenopathy with Perilymphadenitis, depletion of lymphocytes and histiocytosis of the lymph node. In histiocytes and vascular endothelial cells of lymph nodes, septal capillary endothelium of lungs and capillary endothelium of myocardium, early stages of a protozoan parasite were found. In the myocardium, there were many foci of necrosis, some of which contained young cysts in the periphery. These cysts were morphologically similar to those of Sarcocystis. Electron microscopy of the early protozoan stages yielded evidence of schizogony and formation of merozoites.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
ShaoBin LI ◽  
HeQin Zou ◽  
MinMin Gong ◽  
YuQin Chen ◽  
XiaoYong Yan ◽  
...  

Objective. This study aimed to investigate the effects of Ang-1 on neovascularization of diabetic organs by subcutaneous Matrigel angiogenesis model, established in type 1 diabetic rats. Methods. Ang-1 adenoviral vector was constructed. The rat model was established by STZ and divided into four group. The Matrigel was inserted subcutaneously into the abdominal cavity of rats at 8 weeks, the treatment group was injected with Ang-1 adenovirus vector via tail vein, and the rats were sacrificed at 10 weeks. Neovascularization of Matrigel was observed with transmission electron microscopy. The marker of vascular endothelial cell and pericyte were detected by immunofluorescence. Immunohistochemical detection of the neovascular endothelial junction protein was performed. RT-PCR was used to determine protein expression of neovascular in Matrigel. Results. Vascular cavity-like structure could be seen in subcutaneous Matrigel of diabetic rats, and the cavity was filled with a lot of red blood cells. Transmission electron microscopy showed that neovascular endothelial structure of the Matrigel was incomplete, while the Ang-1 treatment group had more vascular cavity-like structures, intact vascular endothelial structure, and reduced inflammatory cell infiltration in Matrigel. Additionally, the integrity of vascularization improved, and the marker of pericyte and the cell tight junctions protein was upregulated in Ang-1 treatment group. Conclusion. Hyperglycemia could induce pathological angiogenesis in subcutaneous Matrigel of diabetic rats, and Ang-1 could upregulate the expression of intercellular junction protein in subcutaneous Matrigel of diabetic rats and promote the integrity of neovascularization in the subcutaneous Matrigel of diabetic rats.


2018 ◽  
Vol 45 (2) ◽  
pp. 558-571 ◽  
Author(s):  
Yun Yi ◽  
Yulin Shen ◽  
Qin Wu ◽  
Jingan Rao ◽  
Shu Guan ◽  
...  

Background/Aims: Diabetes mellitus (DM) has become an increasingly epidemic metabolic disease. Vascular endothelial cells play a key role in developing the cardiovascular complications of DM. The A2B receptor is expressed in vascular endothelial cells, and may help regulate the function of endothelial cells. The aim of this study was to investigate the protective effects of oxymatrine (OMT) on human umbilical vein endothelial cells (HUVECs) from high glucose-induced cytotoxicity. Methods: Homology modeling and molecular docking analysis were used to detect the binding sites between the adenosine A2B receptor and OMT. HUVECs were cultured with control (5.5 mM) or elevated glucose (22.2 mM) in the presence or absence of 3 µM OMT or A2B siRNA for 3 days. The MTS cell viability assay was used to measure the toxicity of high glucose on HUVECs and the protective effect of OMT or A2B siRNA. The expression of the adenosine A2B receptor and CCL5 in HUVECs was detected with real-time quantitative PCR (qPCR) and Western blotting methods in each group. Levels of IL-1β and TNF-α were measured using an enzyme-linked immunosorbent assay (ELISA) kit, and the concentration of NO was detected with the nitrate reductase method. Monocyte chemotactic activity in each group was detected using Transwell chambers. Furthermore, the phosphorylation of p38 and ERK1/2 in each group was observed through the Western blotting method. Results: Homology modeling and molecular docking analysis showed that OMT contains well-fitted binding sites to the A2B receptor. After chronic culture at high glucose, the rate of cell viability was significantly lower than that of the control group. After co-treatment with OMT or A2B siRNA, cell viability was significantly increased compared with the high-glucose group. The results from real-time quantitative RT-PCR (qRT-PCR) and Western blotting indicated that high glucose could increase the expression of A2B receptors in HUVECs, an effect that was inhibited by OMT. In addition, the results revealed that the expression of CCL5, IL-1β and TNF-α was increased in the high-glucose group, and that the NO produced by HUVECs decreased due to hyperglycemia; however, co-culture with OMT or A2B siRNA abolished these effects. Meanwhile, the chemotaxis activity of monocytes to HUVECs cultured in high-glucose medium was enhanced 2.59-fold compared to the control cells. However, the inflammatory reactions in HUVECs were completely relieved by co-treatment with OMT or A2B siRNA. Moreover, the phosphorylation of p38 and ERK1/2 in HUVECs in the high-glucose group was significantly higher than that of the control group; these effects were reversed after co-treatment with OMT or A2B siRNA. Conclusion: OMT may protect the HUVECs from high glucose-induced cytotoxicity through inhibitting the expression of A2B receptor and inflammatory factors as well as decreasing the phosphorylation of p38 and ERK1/2.


1981 ◽  
Author(s):  
T Kjellström ◽  
H Ahlman ◽  
F Dahlström ◽  
G Hansson ◽  
B Stenberg ◽  
...  

Previous studies have shown that 5-HT is rapidly taken up by the endothelial cells and some investigations also suggested that serotonin is metabolized within these cells. In earlier studies on rat-lungs using a fluorescence histo- chemical method according to Hillarp - Falk we demonstrated that 5-HT was accumulated within the mast cells. Using this technique we could not demonstrate any specific uptake in the pulmonary endothelial cells. It was the purpose of the present investigation to further study the 5-HT uptake by isolated pulmonary endothelial cells.Methods Cells from the vascular intima of the pulmonary artery in adult rats were grown in a growth medium containing FCS. The endothelial nature of these cells was demonstrated using transmission electron microscopy and factor VIII analysis. Confluent endothelial cells were incubated with 5-HT and the cellular uptake was studied with fluorescence microscopy according to the Hillarp - Falk procedure.Results The endothelial cells were identified by the presence of Weibel-Palade bodies using transmission electron microscopy and the immunofluorescent demonstration of cellular factor VIII antigen. Cells not exposed to serotonin had no specific 5-HT fluorescense. After incubation with 5-HT at different concentrations there was a progressive uptake of the amine within the cells.Conclusions This study confirms previous reports on the specific serotonin uptake in endothelial cells. The Hillarp-Falk procedure seems suitable for further studies of serotonin uptake in cultured endothelial cells.


2000 ◽  
Vol 68 (9) ◽  
pp. 5416-5419 ◽  
Author(s):  
Harvey A. Schenkein ◽  
Suzanne E. Barbour ◽  
C. R. Berry ◽  
Barbara Kipps ◽  
John G. Tew

ABSTRACT Strains of the periodontal pathogen Actinobacillus actinomycetemcomitans are variable with respect to display of phosphorylcholine (PC)-bearing antigens. We have examined strains ofA. actinomycetemcomitans with and without PC to assess their ability to invade endothelial cells via the receptor for platelet-activating factor (PAF). Results of antibiotic protection assays indicate that PC-bearing A. actinomycetemcomitansinvade human vascular endothelial cells by a mechanism inhibitable by CV3988, a PAF receptor antagonist, and by PAF itself. The invasive phenotype was verified by transmission electron microscopy. A PC-deficient strain of this organism was not invasive. This property, in addition to the established ability of A. actinomycetemcomitans to invade epithelial cells, may provide this organism with access to the systemic circulation. The ability of PC-bearing oral bacteria to access the circulation may also explain the elevated levels of anti-PC antibody in serum found in patients with periodontitis.


Inflammation ◽  
2012 ◽  
Vol 36 (2) ◽  
pp. 300-308 ◽  
Author(s):  
Guilin Li ◽  
Gaochun Zhu ◽  
Yun Gao ◽  
Wen Xiao ◽  
Hong Xu ◽  
...  

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