scholarly journals The Ionophoric Activity of a Pro-Apoptotic VEGF165 Fragment on HUVEC Cells

2020 ◽  
Vol 21 (8) ◽  
pp. 2866
Author(s):  
Stefania Zimbone ◽  
Anna M. Santoro ◽  
Diego La Mendola ◽  
Chiara Giacomelli ◽  
Maria L. Trincavelli ◽  
...  

Copper plays an important role as a regulator in many pathologies involving the angiogenesis process. In cancerogenesis, tumor progression, and angiogenic diseases, copper homeostasis is altered. Although many details in the pathways involved are still unknown, some copper-specific ligands have been successfully used as therapeutic agents. Copper-binding peptides able to modulate angiogenesis represent a possible way to value new drugs. We previously reported that a fragment (VEGF73-101) of vascular endothelial growth factor (VEGF165), a potent angiogenic, induced an apoptotic effect on human umbilical vein endothelial cells. The aim of this study was to investigate the putative copper ionophoric activity of VEGF73-101, as well as establish a relationship between the structure of the peptide fragment and the cytotoxic activity in the presence of copper(II) ions. Here, we studied the stoichiometry and the conformation of the VEGF73-101/Cu(II) complexes and some of its mutated peptides by electrospray ionization mass spectrometry and circular dichroism spectroscopy. Furthermore, we evaluated the effect of all peptides in the absence and presence of copper ions by cell viability and cytofuorimetric assays. The obtained results suggest that VEGF73-101 could be considered an interesting candidate in the development of new molecules with ionophoric properties as agents in antiangiogenic therapeutic approaches.

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Tyler Bammert ◽  
Jamie Hijmans ◽  
Whitney Reiakvam ◽  
Ma’ayan Levy ◽  
Kelly Stockelman ◽  
...  

Clinical interest in endothelial cell-derived microparticles (EMPs) has increased due to their role in the pathogenesis of vascular disease. Although released by the endothelium, EMPs have autocrine properties that can significantly impact endovascular health. Hyperglycemic conditions, such as diabetes, are known to stimulate EMP release; however, the effects of these glucose-related microparticles on endothelial cell function are not well understood. High glucose concentrations induce endothelial cell apoptosis through a caspase-3-dependent mechanism. The aim of this study was to determine the effect of EMPs derived from a hyperglycemic condition on endothelial cell susceptibility to apoptosis. Human umbilical vein endothelial cells (HUVECs) were cultured (3 rd passage) and plated in 6-well plates at a density of 5.0 x 10 5 cell/condition. Cells were incubated with RPMI 1640 media containing 25mM D-glucose (concentration representing a diabetic glycemic state) or 5mM D-glucose (control, normoglycemic, condition) for 48 h to generate EMPs. EMPs derived from both conditions were pelleted by centrifugation and resuspended in culture media. EMP identification (CD144 + expression) and number was determined by flow cytometry. HUVECs (2 x10 6 cells/condition) were treated with EMPs (2:1 ratio) generated from either the hyperglycemic or normoglycemic conditions for 24 h. Thereafter, cells were treated with staurosporine (1μmol/L) for 3 h at 37°C and biotin-ZVKD-fmk inhibitor for 1 h at 37°C. Intracellular concentration of active caspase-3 was determined by enzyme immune assay. Cellular expression of miR-Let7a, an anti-apoptotic microRNA, was determined by RT-PCR using the ΔΔCT normalized to RNU6. Hyperglycemic EMPs resulted in significant increase in basal (1.5 + 0.1 vs 1.0 + 0.1 ng/mL) and staurosporine-stimulated (2.2 + 0.2 vs 1.4 + 0.1 ng/mL) caspase-3 activity compared with normoglycemic EMPs. Additional, the expression of miR-Let7a was markedly reduced (~140%) in response to hyperglycemic EMPs (0.43 + 0.17 fold vs control). These results demonstrate that hyperglycemic-induced EMPs increase endothelial cell apoptotic susceptibility. This apoptotic effect may be mediated, at least in part, by a reduction in miR-Let7a expression.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tao Feng ◽  
Si Zeng ◽  
Jie Ding ◽  
Gong Chen ◽  
Bin Wang ◽  
...  

Abstract Background Angiogenesis, the formation of blood vessel from pre-existing ones, plays an important role in many pathophysiological diseases, such as cancer. Opioids are often used in clinic for the management of chronic pain in cancer patients at terminal phases. Here, we investigated and compared the effects and mechanisms of four opioids on angiogenesis. Methods We performed angiogenesis assays on human umbilical vein endothelial cells (HUVEC) that represent an in vitro model to assess the toxicity of drugs to endothelium. Results Morphine and oxycodone at 0.1 μM to 100 μM dose-dependently increased endothelial cell tube formation and proliferation. We observed the same in endothelial cells exposed to fentanyl at 0.1 μM to 10 μM but there was a gradual loss of stimulation by fentanyl at 100 μM and 1000 μM. Morphine and fentanyl reduced endothelial cell apoptosis-induced by serum withdrawal whereas oxycodone did not display anti-apoptotic effect, via decreasing Bax level. Oxycodone at the same concentrations was less potent than morphine and fentanyl. Different from other three opioids, codeine at all tested concentrations did not affect endothelial cell tube formation, proliferation and survival. Mechanism studies demonstrated that opioids acted on endothelial cells via μ-opioid receptor-independent pathway. Although we observed the increased phosphorylation of mitogen-activated protein kinase (MAPK) in cells exposed to morphine, fentanyl and oxycodone, the rescue studies demonstrated that the stimulatory effects of morphine but not fentanyl nor oxycodone were reversed by a specific MAPK inhibitor. Conclusion Our work demonstrates the differential effects and mechanisms of opioids on angiogenesis.


Author(s):  
D.J.P. Ferguson ◽  
A.R. Berendt ◽  
J. Tansey ◽  
K. Marsh ◽  
C.I. Newbold

In human malaria, the most serious clinical manifestation is cerebral malaria (CM) due to infection with Plasmodium falciparum. The pathology of CM is thought to relate to the fact that red blood cells containing mature forms of the parasite (PRBC) cytoadhere or sequester to post capillary venules of various tissues including the brain. This in vivo phenomenon has been studied in vitro by examining the cytoadherence of PRBCs to various cell types and purified proteins. To date, three Ijiost receptor molecules have been identified; CD36, ICAM-1 and thrombospondin. The specific changes in the PRBC membrane which mediate cytoadherence are less well understood, but they include the sub-membranous deposition of electron-dense material resulting in surface deformations called knobs. Knobs were thought to be essential for cytoadherence, lput recent work has shown that certain knob-negative (K-) lines can cytoadhere. In the present study, we have used electron microscopy to re-examine the interactions between K+ PRBCs and both C32 amelanotic melanoma cells and human umbilical vein endothelial cells (HUVEC).We confirm previous data demonstrating that C32 cells possess numerous microvilli which adhere to the PRBC, mainly via the knobs (Fig. 1). In contrast, the HUVEC were relatively smooth and the PRBCs appeared partially flattened onto the cell surface (Fig. 2). Furthermore, many of the PRBCs exhibited an invagination of the limiting membrane in the attachment zone, often containing a cytoplasmic process from the endothelial cell (Fig. 2).


2019 ◽  
Vol 476 (24) ◽  
pp. 3687-3704 ◽  
Author(s):  
Aphrodite T. Choumessi ◽  
Manuel Johanns ◽  
Claire Beaufay ◽  
Marie-France Herent ◽  
Vincent Stroobant ◽  
...  

Root extracts of a Cameroon medicinal plant, Dorstenia psilurus, were purified by screening for AMP-activated protein kinase (AMPK) activation in incubated mouse embryo fibroblasts (MEFs). Two isoprenylated flavones that activated AMPK were isolated. Compound 1 was identified as artelasticin by high-resolution electrospray ionization mass spectrometry and 2D-NMR while its structural isomer, compound 2, was isolated for the first time and differed only by the position of one double bond on one isoprenyl substituent. Treatment of MEFs with purified compound 1 or compound 2 led to rapid and robust AMPK activation at low micromolar concentrations and increased the intracellular AMP:ATP ratio. In oxygen consumption experiments on isolated rat liver mitochondria, compound 1 and compound 2 inhibited complex II of the electron transport chain and in freeze–thawed mitochondria succinate dehydrogenase was inhibited. In incubated rat skeletal muscles, both compounds activated AMPK and stimulated glucose uptake. Moreover, these effects were lost in muscles pre-incubated with AMPK inhibitor SBI-0206965, suggesting AMPK dependency. Incubation of mouse hepatocytes with compound 1 or compound 2 led to AMPK activation, but glucose production was decreased in hepatocytes from both wild-type and AMPKβ1−/− mice, suggesting that this effect was not AMPK-dependent. However, when administered intraperitoneally to high-fat diet-induced insulin-resistant mice, compound 1 and compound 2 had blood glucose-lowering effects. In addition, compound 1 and compound 2 reduced the viability of several human cancer cells in culture. The flavonoids we have identified could be a starting point for the development of new drugs to treat type 2 diabetes.


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