Marked alteration of proteoglycan metabolism in cholesterol-enriched human arterial smooth muscle cells

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.

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

AJP Cell Physiology ◽

10.1152/ajpcell.1998.275.4.c1031 ◽

1998 ◽

Vol 275 (4) ◽

pp. C1031-C1039 ◽

Cited By ~ 31

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.

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Penetration-induced hyperpolarization as evidence for Ca2+ activation of K+ conductance in isolated smooth muscle cells

AJP Cell Physiology ◽

10.1152/ajpcell.1980.239.5.c182 ◽

1980 ◽

Vol 239 (5) ◽

pp. C182-C189 ◽

Cited By ~ 32

Author(s):

J. V. Walsh ◽

J. J. Singer

Keyword(s):

Smooth Muscle ◽

Steady State ◽

Smooth Muscle Cells ◽

State Level ◽

Input Resistance ◽

Muscle Cells ◽

Enzymatic Digestion ◽

Resting Potential ◽

High Concentration ◽

State Potential

Single smooth muscle cells, freshly isolated by enzymatic digestion of the stomach muscularis of the toad Bufo marinus were studied under direct microscopic observation using standard electrophysiological techniques. Following penetration with a microelectrode, a hyperpolarization lasting many seconds occurred before the membrane depolarized to a steady-state level. The following lines of evidence indicate that the penetration-induced hyperpolarization results from an increase in K+ conductance caused by Ca2+ that enters the cell at the time of penetration: 1) The cell contracted at the time of penetration indicating that [Ca2+]i was elevated even though no action potential had occurred; the cell subsequently relaxed. 2) The input resistance was much lower during the hyperpolarization than during the steady-state resting potential. In the steady state all cells displayed outward-going rectification. 3) At constant [Ca2+]0, the amplitude of the hyperpolarization varied with log[K+]0 (1.3-56 mM) to a much greater degree than did the steady-state potential. Tetraethylammonium chloride (TEA) (18.2 mM) reduced the hyperpolarization. 4) At constant [K+]0, the amplitude of the hyperpolarization increased as the [Ca2+]0 was raised (1.8-52.1 mM). 5) With [Ca2+]0 low (less than or equal to 0.16 mM), the hyperpolarization was almost completely abolished in the presence of a high concentration of Ba2+ (80 mM) or Mn2+ (79.2 mM); this was not the case with Sr2+.

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Cholesterol metabolism in pigeon aortic smooth muscle cells lacking a functional low density lipoprotein receptor pathway.

The Journal of Lipid Research ◽

10.1016/s0022-2275(20)37728-2 ◽

1984 ◽

Vol 25 (9) ◽

pp. 903-912

Author(s):

R K Randolph ◽

B P Smith ◽

R W St Clair

Keyword(s):

Smooth Muscle ◽

Smooth Muscle Cells ◽

Cholesterol Metabolism ◽

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Muscle Cells ◽

Low Density ◽

Lipoprotein Receptor ◽

Aortic Smooth Muscle ◽

Density Lipoprotein Receptor

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Angiotensin II stimulation of rapid paxillin tyrosine phosphorylation correlates with the formation of focal adhesions in rat aortic smooth muscle cells

Journal of Cell Science ◽

10.1242/jcs.108.1.333 ◽

1995 ◽

Vol 108 (1) ◽

pp. 333-342 ◽

Cited By ~ 3

Author(s):

C.E. Turner ◽

K.M. Pietras ◽

D.S. Taylor ◽

C.J. Molloy

Keyword(s):

Smooth Muscle ◽

Angiotensin Ii ◽

Smooth Muscle Cells ◽

Tyrosine Phosphorylation ◽

Focal Adhesions ◽

Fold Increase ◽

Muscle Cells ◽

Aortic Smooth Muscle Cells ◽

Aortic Smooth Muscle ◽

Protein Kinase C Activation

Angiotensin II is a potent vasoconstrictor that has been also implicated in vascular hyperproliferative diseases, including atherosclerosis and restenosis following angioplasty. Treatment of cultured, serum-starved rat aortic smooth muscle cells with angiotensin II causes rapid protein tyrosine phosphorylation that precedes cell mitogenesis. We have identified two of the phosphoproteins as paxillin (75 kilodaltons) and the tyrosine kinase pp125Fak, both components of actin-associated focal adhesion sites. Angiotensin II stimulated a 5-fold increase in the tyrosine phosphorylation of paxillin and a smaller (1.5-fold) increase in pp125Fak tyrosine phosphorylation. Paxillin tyrosine phosphorylation was evident within 1 minute, and was maximal after 10 minutes. Similar elevated protein tyrosine phosphorylation levels of paxillin were obtained with exposure of the rat aortic smooth muscle cells to peptides endothelin-1 and alpha-thrombin that function, as angiotensin II, through binding to members of the seven transmembrane domain G protein coupled receptors. Angiotensin II treatment also stimulated the production of a well-ordered actin-containing stress fiber network and prominent paxillin-containing focal adhesions. The focal adhesions stained intensely with anti-phosphotyrosine antibody suggesting the tyrosine phosphorylation of paxillin and cytoskeletal reorganization were tightly coupled. Angiotensin II receptor occupancy has been shown previously to lead to protein kinase C activation. However, compared to angiotensin II stimulation, a smaller, delayed increase in paxillin tyrosine phosphorylation was observed following direct protein kinase C activation by the phorbol ester phorbol 12-myristate-13-acetate. Paxillin tyrosine phosphorylation was selective for certain agonists since no increase in tyrosine phosphorylation of this protein was observed following exposure to the potent mitogen PDGF. Thus, actin-based cytoskeletal changes involving sites of cell adhesion to the extracellular matrix may play an important role in normal and pathophysiologic smooth muscle cell growth regulation in response to certain angiotensin II-type vasoactive agonists.

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Sorghum Fermented by Aspergillus oryzae NK Enhances Inhibition of Vascular Inflammation in TNF-α-stimulated Human Aortic Smooth Muscle Cells

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000496 ◽

2018 ◽

Vol 88 (5-6) ◽

pp. 309-318

Author(s):

Hae Seong Song ◽

Jung-Eun Kwon ◽

Hyun Jin Baek ◽

Chang Won Kim ◽

Hyelin Jeon ◽

...

Keyword(s):

Smooth Muscle ◽

Inflammatory Response ◽

Smooth Muscle Cells ◽

Adhesion Molecule ◽

Vascular Inflammation ◽

Muscle Cells ◽

Aortic Smooth Muscle Cells ◽

Aortic Smooth Muscle ◽

Tnf Α ◽

Cox 2

Abstract. Sorghum bicolor L. Moench is widely grown all over the world for food and feed. The effects of sorghum extracts on general inflammation have been previously studied, but its anti-vascular inflammatory effects are unknown. Therefore, this study investigated the anti-vascular inflammation effects of sorghum extract (SBE) and fermented extract of sorghum (fSBE) on human aortic smooth muscle cells (HASMCs). After the cytotoxicity test of the sorghum extract, a series of experiments were conducted. The inhibition effects of SBE and fSBE on the inflammatory response and adhesion molecule expression were measured using treatment with tumor necrosis factor-α (TNF-α), a crucial promoter for the development of atherosclerotic lesions, on HASMCs. After TNF-α (10 ng/mL) treatment for 2 h, then SBE and fSBE (100 and 200 μg/mL) were applied for 12h. Western blotting analysis showed that the expression of vascular cell adhesion molecule-1 (VCAM-1) (2.4-fold) and cyclooxygenase-2 (COX-2) (6.7-fold) decreased, and heme oxygenase-1 (HO-1) (3.5-fold) increased compared to the TNF-α control when treated with 200 μg/mL fSBE (P<0.05). In addition, the fSBE significantly increased the expression of HO-1 and significantly decreased the expression of VCAM-1 and COX-2 compared to the TNF-α control in mRNA level (P<0.05). These reasons of results might be due to the increased concentrations of procyanidin B1 (about 6-fold) and C1 (about 30-fold) produced through fermentation with Aspergillus oryzae NK for 48 h, at 37 °C. Overall, the results demonstrated that fSBE enhanced the inhibition of the inflammatory response and adherent molecule expression in HASMCs.

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