scholarly journals Chlamydia pneumoniae Infection of Human Endothelial Cells Induces Proliferation of Smooth Muscle Cells via an Endothelial Cell-Derived Soluble Factor(s)

1999 ◽  
Vol 67 (6) ◽  
pp. 2909-2915 ◽  
Author(s):  
Brian K. Coombes ◽  
James B. Mahony
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Endothelial Cell ◽  
Smooth Muscle Cells ◽  
Chlamydia Pneumoniae ◽  
Umbilical Vein ◽  
Muscle Cells ◽  
Cell Counting ◽  
Soluble Factor ◽  
Dose Dependent

ABSTRACT An association of Chlamydia pneumoniae with atherosclerosis and coronary heart disease has been determined epidemiologically and by the detection of C. pneumoniaeorganisms in atherosclerotic lesions in both humans and animal models of atherosclerosis. Previously, it has been shown that C. pneumoniae is capable of replicating in cell types found within atheromatous lesions, viz., endothelial cells, smooth muscle cells (SMC), and macrophages, yet the role of C. pneumoniae in the pathogenesis of atherosclerosis has not been determined. Since intimal thickening is a hallmark of atherosclerosis, we investigated whether C. pneumoniae infection of human umbilical vein endothelial cells (HUVEC) could induce the expression of a soluble factor(s) with mitogenic potential for SMC by using [3H]thymidine incorporation and direct cell counting. Conditioned medium harvested from HUVEC infected with C. pneumoniae stimulated SMC replication in a time- and dose-dependent fashion. Infection studies using various multiplicities of infection (MOIs) ranging from 0.001 to 1 demonstrated a dose-dependent production of the soluble factor(s). At an MOI of 1, SMC stimulation indices were 8.4 (P < 0.01) and 12.2 (P < 0.01) for conditioned media harvested at 24 and 48 h, respectively. To determine whether viable C. pneumoniae was required for production of the soluble factor(s), HUVEC were infected with heat-inactivated C. pneumoniae or with viable organisms in the presence of chloramphenicol. Both treatments produced stimulation indices similar to those for liveC. pneumoniae in the absence of chloramphenicol (P > 0.05), indicating that the factor(s) was produced by HUVEC and not by C. pneumoniae and that signal transduction events following chlamydia endocytosis may be important in the production of a soluble factor(s). The ability of C. pneumoniae to elicit an endothelial cell-derived soluble factor(s) that stimulates SMC proliferation may be important in the pathogenesis of atherosclerosis.

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
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Steady State ◽  
Smooth Muscle Cells ◽  
Umbilical Vein ◽  
State Level ◽  
Muscle Cells ◽  
Free Access ◽  
Steady State Level ◽  
Human Umbilical Vein

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.

Electrical activation of endothelium evokes vasodilation and hyperpolarization along hamster feed arteries

2001 ◽  
Vol 280 (1) ◽  
pp. H160-H167 ◽  
Author(s):  
Geoffrey G. Emerson ◽  
Steven S. Segal
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Endothelial Cell ◽  
Smooth Muscle Cells ◽  
Cell Damage ◽  
Muscle Cells ◽  
Sympathetic Nerves ◽  
Retractor Muscle ◽  
Receptor Interactions ◽  
Feed Arteries

Endothelial cells are considered electrically unexcitable. However, endothelium-dependent vasodilators (e.g., acetylcholine) often evoke hyperpolarization. We hypothesized that electrical stimulation of endothelial cells could evoke hyperpolarization and vasodilation. Feed artery segments (resting diameter: 63 ± 1 μm; length 3–4 mm) of the hamster retractor muscle were isolated and pressurized to 75 mmHg, and focal stimulation was performed via microelectrodes positioned across one end of the vessel. Stimulation at 16 Hz (30–50 V, 1-ms pulses, 5 s) evoked constriction (−20 ± 2 μm) that spread along the entire vessel via perivascular sympathetic nerves, as shown by inhibition with tetrodotoxin, ω-conotoxin, or phentolamine. In contrast, stimulation with direct current (30 V, 5 s) evoked vasodilation (16 ± 2 μm) and hyperpolarization (11 ± 1 mV) of endothelial and smooth muscle cells that conducted along the entire vessel. Conducted responses were insensitive to preceding treatments, atropine, or N ω-nitro-l-arginine, yet were abolished by endothelial cell damage (with air). Injection of negative current (≤1.6 nA) into a single endothelial cell reproduced vasodilator responses along the entire vessel. We conclude that, independent of ligand-receptor interactions, endothelial cell hyperpolarization evokes vasodilation that is readily conducted along the vessel wall. Moreover, electrical events originating within a single endothelial cell can drive the relaxation of smooth muscle cells throughout the entire vessel.

Effects of 2-Deoxy-d-Glucose on Proliferation of Vascular Smooth Muscle Cells and Endothelial Cells

2008 ◽  
Vol 36 (5) ◽  
pp. 986-991 ◽  
Author(s):  
HM Nef ◽  
H Möllmann ◽  
A Joseph ◽  
C Troidl ◽  
S Voss ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Inhibitory Effect ◽  
Short Term ◽  
Inhibition Of Proliferation ◽  
Aortic Endothelial Cells ◽  
Intracoronary Stenting ◽  
Dose Dependent

2-Deoxy-d-glucose (2-DG) is a glucose analogue that has been proposed for cancer therapy due to its cytostatic properties. Its effect on the proliferation of smooth muscle cells and endothelial cells has not been fully clarified. The aims of this study were to investigate the effects of 2-DG on the proliferation of porcine aortic endothelial cells (PAEC) and porcine smooth muscle cells (PSMC), to establish an overview of its dose-dependent inhibitory capacity and to examine whether the short-term incubation of cells with 2-DG has an impact on cell proliferation in culture. Our results showed a dose-dependent significant inhibitory effect on proliferation, which was more pronounced in PSMC than in PAEC. Even after short-term incubation of cells with 2-DG, relevant inhibition of proliferation was documented. The clinical application of 2-DG might be a promising concept by inhibiting cells that show a potentially rapid proliferation in response to non-malignant stimuli, such as smooth muscle cells after intracoronary stenting.

scholarly journals IL-8 reduces VCAM-1 secretion of smooth muscle cells by increasing p-ERK expression when 3-D co-cultured with vascular endothelial cells

2011 ◽  
Vol 34 (3) ◽  
pp. 138 ◽  
Author(s):  
Zhi Zhang ◽  
Guang Chu ◽  
Hong-Xian Wu ◽  
Ni Zou ◽  
Bao-Gui Sun ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Type I Collagen ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Muscle Cells ◽  
Type I ◽  
Vascular Endothelial ◽  
Culture Model

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.

scholarly journals Glycyrrhetinic derivatives inhibit hyperpolarization in endothelial cells of guinea pig and rat arteries

2002 ◽  
Vol 282 (1) ◽  
pp. H335-H341 ◽  
Author(s):  
Marianne Tare ◽  
H. A. Coleman ◽  
Helena C. Parkington
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Endothelial Cell ◽  
Guinea Pig ◽  
Smooth Muscle Cells ◽  
Time Course ◽  
Muscle Cells ◽  
Mesenteric Arteries ◽  
Resting Membrane Potential ◽  
Variable Effect

Glycyrrhetinic acid (GA) derivatives have been used to implicate gap junctions in vasorelaxation attributed to endothelium-derived hyperpolarizing factor (EDHF). The aim of this study was to assess whether GA compounds affect endothelial cell hyperpolarization. Membrane potentials were recorded from dye-identified endothelial and smooth muscle cells of guinea pig coronary and rat mesenteric arteries. GA derivatives had varied effects on the resting membrane potential: depolarization, hyperpolarization, or no effect, depending on the artery. 18α-GA (50 μM) had a small variable effect on ACh-induced hyperpolarizations in endothelial cells. 18β-GA (30 μM) and carbenoxolone (100 μM) significantly reduced ACh-induced hyperpolarizations in both endothelial and smooth muscle cells. Smooth muscle action potentials in rat tail arteries were smaller and slower in the presence of 18β-GA. Nerve-induced excitatory junction potentials were inhibited by 18β-GA and carbenoxolone, whereas the time course of their decay initially increased and then decreased. In conclusion, the GA compounds had a range of effects. Their inhibition of the EDHF hyperpolarization and relaxation in the smooth muscle may stem from the inhibition of endothelial cell hyperpolarization.

scholarly journals An endothelial cell-derived growth factor.

1980 ◽  
Vol 85 (2) ◽  
pp. 467-472 ◽  
Author(s):  
C Gajdusek ◽  
P DiCorleto ◽  
R Ross ◽  
S M Schwartz
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Platelet Derived Growth Factor ◽  
3T3 Cells ◽  
Free Plasma ◽  
Heat Instability

Cell-free plasma-derived serum (PDS) is deficient in the platelet-derived growth factor and will not support the growth of 3T3 cells, fibroblasts, or smooth muscle cells. However, when PDS-containing medium is preincubated with endothelial cells, the medium becomes modified so that it will support growth. The activity produced by the endothelial cells results from a polypeptide of 10,000 to 30,000 daltons which has several features that differ from those of the platelet-derived growth factor, including heat instability and lack of adsorption to CM Sephadex.

Intercellular calcium signaling and nitric oxide feedback during constriction of rabbit renal afferent arterioles

2007 ◽  
Vol 292 (4) ◽  
pp. F1124-F1131 ◽  
Author(s):  
T. R. Uhrenholt ◽  
J. Schjerning ◽  
P. M. Vanhoutte ◽  
B. L. Jensen ◽  
O. Skøtt
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Smooth Muscle ◽  
Endothelial Cell ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Calcium Sensitivity ◽  
No Production ◽  
Contractile Apparatus ◽  
Afferent Arterioles

Vasoconstriction and increase in the intracellular calcium concentration ([Ca2+]i) of vascular smooth muscle cells may cause an increase of endothelial cell [Ca2+]i, which, in turn, augments nitric oxide (NO) production and inhibits smooth muscle cell contraction. This hypothesis was tested in microperfused rabbit renal afferent arterioles, using fluorescence imaging microscopy with the calcium-sensitive dye fura-2 and the NO-sensitive dye 4-amino-5-methylamino-2′,7′-difluorescein. Both dyes were loaded into smooth muscle and endothelium. Depolarization with 100 mmol/l KCl led to a transient vasoconstriction which was converted into a sustained response by N-nitro-l-arginine methyl ester (l-NAME). Depolarization increased smooth muscle cell [Ca2+]ifrom 162 ± 15 nmol/l to a peak of 555 ± 70 nmol/l ( n = 7), and this response was inhibited by 80% by the l-type calcium channel blocker calciseptine. After a delay of 10 s, [Ca2+]iincreased in endothelial cells immediately adjacent to reactive smooth muscle cells, and this calcium wave spread in a nonregenerative fashion laterally into the endothelial cell layer with a velocity of 1.2 μm/s. Depolarization with 100 mmol/l KCl led to a significant increase in NO production ([NO]i) which was inhibited by l-NAME ( n = 5). Acetylcholine caused a rapid increase in endothelial [Ca2+]i, which did not transfer to the smooth muscle cells. l-NAME treatment did not affect changes in smooth muscle [Ca2+]iafter depolarization, but it did increase the calcium sensitivity of the contractile apparatus. We conclude that depolarization increases smooth muscle [Ca2+]iwhich is transferred to the endothelial cells and stimulates NO production which curtails vasoconstriction by reducing the calcium sensitivity of the contractile apparatus.

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