Ascorbate and glutathione homeostasis in vascular smooth muscle cells: cooperation with endothelial cells

1998 ◽  
Vol 275 (4) ◽  
pp. C1031-C1039 ◽  
Author(s):  
Ilia Voskoboinik ◽  
Karin Söderholm ◽  
Ian A. Cotgreave

Human umbilical vein smooth muscle cells (HUVSMCs) utilize extracellular cystine, glutathione (GSH), and N-acetylcysteine (NAC) to synthesize cellular GSH. Extracellular cystine was effective from 5 μM, whereas GSH and NAC were required at 100 μM for comparable effects. The efficacy of extracellular GSH was dependent on de novo GSH synthesis, indicating a dependence on cellular γ-glutamyltransferase (glutamyl transpeptidase). Coculture of syngenetic HUVSMCs and corresponding human umbilical vein endothelial cells (HUVECs) on porous supports restricted cystine- or GSH-stimulated synthesis of HUVSMC GSH when supplied on the “luminal” endothelial side. Thus HUVSMC GSH rapidly attained a steady-state level below that achieved in the absence of interposed HUVECs. HUVSMCs also readily utilize both reduced ascorbate (AA) and oxidized dehydroascorbate (DHAA) over the range 50–500 μM. Phloretin effectively blocked both AA- and DHAA-stimulated assimilation of intracellular AA, indicating a role for a glucose transporter in their transport. Uptake of extracellular AA was also sensitive to extracellular, but not intracellular, thiol depletion. When AA was applied to the endothelial side of the coculture model, assimilation of intracellular AA in HUVSMCs was restricted to a steady-state level below that achieved by free access.

1996 ◽  
Vol 315 (3) ◽  
pp. 995-1000 ◽  
Author(s):  
Parakat VIJAYAGOPAL ◽  
Julio E. FIGUEROA ◽  
Qi GUO ◽  
Jason D. FONTENOT ◽  
Zhuo TAO

To elucidate the correlation between vascular cholesterol metabolism and proteoglycan (PrGl) biosynthesis, we investigated PrGl synthesis in human aortic smooth muscle cells (SMCs) after cholesterol enrichment with cationized low-density lipoproteins (LDL). Compared with normal SMCs, total PrGl synthesis by cholesterol-enriched cells decreased 2.4-fold (11874±530 d.p.m. per 105 cells compared with 4890±385 d.p.m. per 105 cells). This was the net result of a 6.9-fold reduction in medium PrGl (11000±490 d.p.m. per 105 cells compared with 1580± 246 d.p.m. per 105 cells) and a 3.8-fold increase in cellular PrGl over controls (874±27 d.p.m. per 105 cells compared with 3310±193 d.p.m. per 105 cells). Prior incubation of SMCs with native LDL had no effect on PrGl synthesis by these cells. The decrease in PrGl synthesis in cholesterol-enriched cells correlated with a 90% and 20% reduction in the steady-state level of mRNA for biglycan and decorin respectively, and a virtual elimination of the steady-state level of mRNA for versican over controls. Despite the down-regulation of PrGl synthesis, cholesterol-loaded cells produced a 2-fold increase in a PrGl subfraction with high affinity for LDL. Compared with the corresponding PrGl subfraction from normal cells, that from the cholesterol-enriched cells exhibited increased charge density and a higher molecular mass and contained relatively larger proportions of chondroitin 6-sulphate and dermatan sulphate. These results show that PrGl metabolism is dramatically altered in cholesterol-enriched human SMCs.


1998 ◽  
Vol 60 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Roland Walter ◽  
Philippe Linscheid ◽  
Nenad Blau ◽  
Lucja Kierat ◽  
Andreas Schaffner ◽  
...  

2011 ◽  
Vol 34 (3) ◽  
pp. 138 ◽  
Author(s):  
Zhi Zhang ◽  
Guang Chu ◽  
Hong-Xian Wu ◽  
Ni Zou ◽  
Bao-Gui Sun ◽  
...  

Objective: The goal of this study was to investigate the crosstalk between vascular endothelial cells (ECs) and smooth muscle cells (SMCs) using a three-dimensional (3-D) co-culture model. In addition, the role of IL-8 in this crosstalk was investigated. Methods: A 3-D co-culture model was constructed using a Transwell chamber system and type I collagen gel. Human umbilical artery smooth muscle cells (HUASMCs) were suspended in the gel and added to the upper compartment of the Transwell. Human umbilical vein endothelial cells (HUVECs) were then grown on the surface of the gel. The growth of HUASMCs was tested with a CFDA SE cell proliferation kit. IL-8 and other bioactive substances were investigated by ELISA and real-time PCR. The alteration of p-ERK expression related to the change in IL-8 levels was also examined by Western blot analysis. Results: The proliferation rate of HUASMCs in the 3-D co-culture model was 0.679 ± 0.057. Secretion and transcription of VEGF, t-PA, NO and VCAM-1 in the 3-D co-culture model were different than in single (2-D) culture. When 3-D co-cultured, IL-8 released by HUVECs was significantly increased (2.35 ± 0.16 fold) (P﹤0.05) and the expression of VCAM-1 from HUASMCs was reduced accordingly (0.55±0.09 fold). In addition, increasing or decreasing the level of IL-8 changed the level of p-ERK and VCAM-1 expression. The reduction of VCAM-1, resulting from increased IL-8, could be blocked by the MEK inhibitor, PD98059. Conclusion: Crosstalk between HUVECs and HUASMCs occurred and was probably mediated by IL-8 in this 3-D co-culture model.


1996 ◽  
Vol 76 (04) ◽  
pp. 603-609 ◽  
Author(s):  
Rose-Marie Catalioto ◽  
Paola Cucchi ◽  
Anna Rita Renzetti ◽  
Marco Criscuoli ◽  
Alessandro Subissi

SummaryThe aim of the present work was to study how human umbilical vein smooth muscle cells (HUVSMC) can initiate the coagulation process and to investigate the responses of these cells to thrombin. Exposure of HUVSMC to recalcified human plasma led to a time-dependent production of thrombin, measured both as amidolytic activity and as release of fibrinopeptide A. Thrombin activity was dose-dependently reduced by an anti-human tissue factor antibody (76 ± 3% at 10 Μg/ml) and by inhibitors like heparin, rec-hirudin, hirulog-1, Napap and hiru-norm, a novel hirudin-like thrombin inhibitor (IC50 = 2 ± 0.4, 8 ± 1, 130 ± 22, 199 ± 29 and 68 ± 8nM, respectively). The release of fibrinopeptide A was similarly prevented (IC50 = 14 ± 1,132 ± 25 and 50 ± 8 nM for rec-hirudin, Napap and hirunorm, respectively). Exogenously added thrombin increased thymidine incorporation into HUVSMC to 240 ± 30% of basal (EC50 = 0.49 ± 0.09 nM) and thrombin inhibitors blocked this effect (IC50 = 10 ± 3, 37 ± 17, 343 ± 165 and 1402 ± 758 nM for rec-hirudin, hirunorm, Napap and hirulog-1, respectively). Also recalcified human plasma was mitogenic for HUVSMC and its effect was mainly due to endogenously generated thrombin, as shown by the use of thrombin inhibitors. In conclusion, HUVSMC are capable of initiating the extrinsic coagulation cascade, leading to the formation of thrombin which promotes clotting and stimulates DNA synthesis. Thrombin inhibitors prevent both coagula-tive and cellular effects of thrombin.


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