Nicotine improves the functional activity of late endothelial progenitor cells via nicotinic acetylcholine receptors

2011 ◽  
Vol 89 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Min Yu ◽  
Qian Liu ◽  
Jing Sun ◽  
Kaihong Yi ◽  
Libiao Wu ◽  
...  

The aim of this study is to investigate whether nicotinic acetylcholine receptors (nAChRs) are involved in the modulation of functional activity of late endothelial progenitor cells (EPCs) induced by nicotine. Total mononuclear cells (MNCs) were isolated from human umbilical cord blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture plates. Late EPCs were positive for 1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine-labeled acetylated low-density lipoprotein (DiI-acLDL) uptake and fluorescein-isothiocyanate-conjugated Ulex europaeus agglutinin lectin (UEA-1) binding. Expression of von Willbrand factor (vWF), kinase insert domain receptor (KDR), and α7 nAChR was detected by indirect immunofluorescence staining. Late EPCs of 3–5 passages were treated for 32 h with either vehicle or nicotine with or without pre-incubation of nAChR antagonism, mecamylamine, or α-bungarotoxin. The viability, migration, and in vitro vasculogenesis activity of late EPCs were assayed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, modified Boyden chamber assay, and in vitro angiogenesis assay, respectively. Late EPCs adhesion assay was performed by replating cells on fibronectin-coated plates, and then adherent cells were counted. Incubation with 10 nmol/L nicotine enhanced viable, migratory, adhesive, and in vitro vasculogenesis capacity of late EPCs. The effect of nicotine on late EPCs can be attenuated by mecamylamine or α-bungarotoxin. In conclusion, nicotine improves the functional activity of late EPCs via nAChRs.

2004 ◽  
Vol 107 (3) ◽  
pp. 273-280 ◽  
Author(s):  
Jun Zhu CHEN ◽  
Fu Rong ZHANG ◽  
Qian Min TAO ◽  
Xing Xiang WANG ◽  
Jian Hua ZHU ◽  
...  

Hypercholesterolaemia contributes to atherosclerosis and coronary artery diseases by inducing endothelial cell injury and dysfunction. Recent studies have provided increasing evidence that EPCs (endothelial progenitor cells) participate in ongoing endothelial repair and postnatal neovascularization. However, the changes in EPCs in patients with hypercholesterolaemia have not been elucidated to date. Therefore we investigated the number and functional activity of EPCs in patients with hypercholesterolemia. Total MNCs (mononuclear cells) were isolated from 20 patients with hypercholesterolaemia and 20 matched control subjects. EPCs were characterized as adherent cells double-positive for DiI-LDL (1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanide percholate-labelled low-density lipoprotein) uptake and lectin binding by direct fluorescent staining under a laser scanning confocal microscope, and were characterized further by demonstrating the expression of KDR (kinase insert domain-containing receptor), CD34 and AC133 by flow cytometry. Proliferation, migration and in vitro vasculogenesis activity of EPCs were assayed using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay, modified Boyden chamber assay and an in vitro vasculogenesis kit respectively. EPC adhesion assay was performed by replating cells on fibronectin-coated dishes and then counting the adherent cells. As a result, the number of EPCs was significantly reduced in patients with hypercholes-terolaemia compared with that in control subjects (41.8±8.7 compared with 64.5±16.6 EPCs/×200 field respectively; P<0.05). The number of EPCs was inversely correlated with total cholesterol (r=−0.659, P<0.001) and LDL-cholesterol (r=−0.611, P<0.001) levels. In addition, the functional activities of isolated EPCs, such as proliferative, migratory, adhesive and in vitro vasculogenesis capacity, were also impaired. In conclusion, the results of the present study may state a novel pathophysiological mechanism of hypercholesterolaemia: the reduction of EPCs with decreased functional activity.


2014 ◽  
Vol 1 (1-4) ◽  
pp. 10-16 ◽  

Vascular tissue engineering attempts to grow blood vessels through the use of different scaffolds that allows vascular cells such as endothelial cells to form networks and organized in vascular tissue. Various biomaterials are used to produce scaffolds that allow growth and differentiation of stem cells; depending on the cell type and applications some materials are more suitable than other. The aim of this study was to evaluate the cytocompatibility of collagen based scaffolds and to assess the capacity of endothelial progenitor cells (EPC) isolated from human umbilical cord to form vascular networks on these scaffolds. Our results show that after 5 days in culture with collagen scaffolds, the EPC remained viable, a sign of biocompatibility with the 3D scaffolds. Scanning electron microscopy showed that in the collagen scaffolds EPC organize within networks and presents an abundant extracellular matrix that strengthen the links between them. When EPC were cultured on collagenchitosan scaffolds, they are more adherent to the scaffolds compared with collagen, exibiting a good capacity to form networks. This study shows that the collagen and collagen-chitosan scaffolds are not cytotoxic for EPC and they provide the possibility of being used in vascular tissue engineering to help creating blood vessels.


2007 ◽  
Vol 30 (4) ◽  
pp. 96
Author(s):  
Michael R. Ward ◽  
Qiuwang Zhang ◽  
Duncan J. Stewart ◽  
Michael J.B. Kutryk

Autologous endothelial progenitor cells (EPCs) have been used extensively in the development of cell-based therapy for acute MI. However, EPCs isolated from patients with CAD and/or CAD risk factors have reduced regenerative activity compared to cells from healthy subjects. As in endothelial cells, endothelial NO synthase (eNOS) expression and subsequent NO production are believed to be critical determinants of EPC function. Recently, the ability of EPCs to migrate in vitro in response to chemotactic stimuli has been shown to predict their regenerative capacity in clinical studies. Therefore, we hypothesized that the regenerative function of EPCs from patients with or at high risk for CAD will be enhanced by overexpression of eNOS, as assessed by migratory capacity. Methods: EPCs were isolated from the blood of human subjects with CAD risk factors (>15% Framingham risk score; FRS) (± CAD) by Ficoll gradient separation and differential culture. Following 3 days in culture, cells were transduced using lentivirus vectors containing either eNOS or GFP (sham) at an MOI of 3. The cells were cultured for an additional 5 days before being used in functional assays. Cell migration and chemotaxis in response to VEGF (50 ng/mL) and SDF-1 (100 ng/mL) were assessed using a modified Boyden Chamber assay. Results: Transduction at an MOI of 3 led to a ~90-100-fold increase in eNOS mRNA expression and a 5-6 fold increase in eNOS protein expression, as assessed by qRT-PCR and Western Blotting. Moreover, there was a significant improvement in the migration of EPCs following eNOS transduction compared to sham-transduced EPCs in response to both VEGF (44.3 ± 8.4 vs. 31.1 ± 4.6 cells/high power field; n=10, p < 0.05) and SDF-1 (51.9 ± 11.1 vs. 34.5 ± 3.3 cells/HPF; n=10, p < 0.05). Conclusions: These data show that the reduced migration capacity of EPCs isolated from patients with CAD and/or CAD risk factors can be significantly improved through eNOS overexpression in these cells. Thus, eNOS transduction of autologous EPCs may enhance their ability to restore myocardial perfusion and function following acute MI. We intend to further explore the regenerative potential of eNOS-transduced EPCs using various in vitro and in vivo models.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1152
Author(s):  
Alberto Polo-Montalvo ◽  
Laura Casarrubios ◽  
María Concepción Serrano ◽  
Adrián Sanvicente ◽  
María José Feito ◽  
...  

Due to their specific mesoporous structure and large surface area, mesoporous bioactive glasses (MBGs) possess both drug-delivery ability and effective ionic release to promote bone regeneration by stimulating osteogenesis and angiogenesis. Macrophages secrete mediators that can affect both processes, depending on their phenotype. In this work, the action of ion release from MBG-75S, with a molar composition of 75SiO2-20CaO-5P2O5, on osteogenesis and angiogenesis and the modulatory role of macrophages have been assessed in vitro with MC3T3-E1 pre-osteoblasts and endothelial progenitor cells (EPCs) in monoculture and in coculture with RAW 264.7 macrophages. Ca2+, phosphorous, and silicon ions released from MBG-75S were measured in the culture medium during both differentiation processes. Alkaline phosphatase activity and matrix mineralization were quantified as the key markers of osteogenic differentiation in MC3T3-E1 cells. The expression of CD31, CD34, VEGFR2, eNOS, and vWF was evaluated to characterize the EPC differentiation into mature endothelial cells. Other cellular parameters analyzed included the cell size and complexity, intracellular calcium, and intracellular content of the reactive oxygen species. The results obtained indicate that the ions released by MBG-75S promote osteogenesis and angiogenesis in vitro, evidencing a macrophage inhibitory role in these processes and demonstrating the high potential of MBG-75S for the preparation of implants for bone regeneration.


2011 ◽  
Vol 286 (12) ◽  
pp. 10618-10627 ◽  
Author(s):  
Ekaterina N. Lyukmanova ◽  
Zakhar O. Shenkarev ◽  
Mikhail A. Shulepko ◽  
Konstantin S. Mineev ◽  
Dieter D'Hoedt ◽  
...  

Discovery of proteins expressed in the central nervous system sharing the three-finger structure with snake α-neurotoxins provoked much interest to their role in brain functions. Prototoxin LYNX1, having homology both to Ly6 proteins and three-finger neurotoxins, is the first identified member of this family membrane-tethered by a GPI anchor, which considerably complicates in vitro studies. We report for the first time the NMR spatial structure for the water-soluble domain of human LYNX1 lacking a GPI anchor (ws-LYNX1) and its concentration-dependent activity on nicotinic acetylcholine receptors (nAChRs). At 5–30 μm, ws-LYNX1 competed with 125I-α-bungarotoxin for binding to the acetylcholine-binding proteins (AChBPs) and to Torpedo nAChR. Exposure of Xenopus oocytes expressing α7 nAChRs to 1 μm ws-LYNX1 enhanced the response to acetylcholine, but no effect was detected on α4β2 and α3β2 nAChRs. Increasing ws-LYNX1 concentration to 10 μm caused a modest inhibition of these three nAChR subtypes. A common feature for ws-LYNX1 and LYNX1 is a decrease of nAChR sensitivity to high concentrations of acetylcholine. NMR and functional analysis both demonstrate that ws-LYNX1 is an appropriate model to shed light on the mechanism of LYNX1 action. Computer modeling, based on ws-LYNX1 NMR structure and AChBP x-ray structure, revealed a possible mode of ws-LYNX1 binding.


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