Endothelial cell-derived pro-fibrotic factors increase TGF-β1 expression by smooth muscle cells in response to cycles of hypoxia-hyperoxia

2022 ◽  
Vol 1868 (1) ◽  
pp. 166278
Author(s):  
Ahmed Ismaeel ◽  
Dimitrios Miserlis ◽  
Evlampia Papoutsi ◽  
Gleb Haynatzki ◽  
William T. Bohannon ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Endothelial Cell ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Tgf Β1

IGFBP-3 activates TGF-β receptors and directly inhibits growth in human intestinal smooth muscle cells

2004 ◽  
Vol 287 (4) ◽  
pp. G795-G802 ◽  
Author(s):  
John F. Kuemmerle ◽  
Karnam S. Murthy ◽  
Jennifer G. Bowers
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Nuclear Translocation ◽  
Thymidine Incorporation ◽  
Muscle Cells ◽  
Serine Phosphorylation ◽  
Intestinal Smooth Muscle ◽  
Igf I ◽  
Tgf Β1 ◽  
Igfbp 3

We have shown that human intestinal smooth muscle cells produce IGF-I and IGF binding protein-3 (IGFBP-3). Endogenous IGF-I acts in autocrine fashion to stimulate growth of these cells. IGFBP-3 inhibits the binding of IGF-I to its receptor and thereby inhibits IGF-I-stimulated growth. In several carcinoma cell lines and some normal cells, IGFBP-3 regulates growth independently of IGF-I. Two mechanisms for this effect have been identified: IGFBP-3 can directly activate transforming growth factor-β (TGF-β) receptors or it can undergo direct nuclear translocation. The aim of the present study was to determine whether IGFBP-3 acts independently of IGF-I and to characterize the mechanisms mediating this effect in human intestinal smooth muscle cells. The direct effects of IGFBP-3 were determined in the presence of an IGF-I receptor antagonist to eliminate its IGF-I-dependent effects. Affinity labeling of TGF-β receptors (TGF-βRI, TGF-βRII, and TGF-βRV) with 125I-labeled TGF-β1 showed that IGFBP-3 displaced binding to TGF-βRII and TGF-βRV in a concentration-dependent fashion. IGFBP-3 stimulated TGF-βRII-dependent serine phosphorylation (activation) of both TGF-βRI and of its primary substrate, Smad2(Ser465/467). IGFBP-3 also caused IGF-I-independent inhibition of basal [3H]thymidine incorporation. The effects of IGFBP-3 on Smad2 phosphorylation and on smooth muscle cell proliferation were independent of TGF-β1 and were abolished by transfection of Smad2 siRNA. Immunoneutralization of IGFBP-3 increased basal [3H]thymidine incorporation, implying that endogenous IGFBP-3 inhibits proliferation. We conclude that endogenous IGFBP-3 directly inhibits proliferation of human intestinal smooth muscle cells by activation of TGF-βRI and Smad2, an effect that is independent of its effect on IGF-I-stimulated growth.

The Role of Endothelial Cell Injury and Platelet Response in Atherogenesis

1977 ◽  
Author(s):  
L. A. Harker ◽  
R. Ross ◽  
J. Glomset
Keyword(s):  
Smooth Muscle ◽  
Endothelial Cell ◽  
Connective Tissue ◽  
Smooth Muscle Cells ◽  
Lipid Accumulation ◽  
Blood Platelets ◽  
Muscle Cells ◽  
Endothelial Injury ◽  
Intimal Proliferation ◽  
Flowing Blood

Endothelium forms a resistant barrier between flowing blood and vessel wall structures. Endothelial thromboresistance is maintained in part by the synthesis of prostacyclin, a potent prostaglandin inhibitor of platelet function. Loss of endothelial cells, mediated by physical, chemical, infectious or immune mechanisms, exposes the sub endothelium to flowing blood. Platelets react to the subendothelial connective tissue structures, undergoing adhesion and release of intracellular constituents, including a factor that is mitogenic to smooth muscle cells. This growth factor is a heat stable, basic protein (IP 7.4–9.4) of 20,000 Daltons and appears to be responsible for the intimal proliferation of smooth muscle cells that follows endothelial cell desquamation. After a single injury event the intimal lesion regresses over several months. Repeated or continuous endothelial cell loss results in progressive intimal proliferation of smooth muscle cells, their secretion of connective tissue matrix components (collagen, elastin and proteoglycans) and accumulation of lipid when animals are on a hypercholesterolemic diet to form early atherosclerotic intimal lesions. Discontinuance of endothelial injury and restoration of the endothelium appear to be followed by lesion regression except when lipid accumulation is extensive. Possible approaches to atherosclerosis prevention include: 1) protection of the endothelium by interruption or avoidance of endothelial injury factors, and perhaps by pharmacologic protection; 2) inhibition of platelet reactivity; 3) modification of SMC proliferation, secretion or lipid accumulation.

PDGF-BB-induced DNA synthesis is delayed by angiotensin II in vascular smooth muscle cells

1998 ◽  
Vol 274 (5) ◽  
pp. H1742-H1748 ◽  
Author(s):  
Gunilla Dahlfors ◽  
Yun Chen ◽  
Maria Wasteson ◽  
Hans J. Arnqvist
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Dna Synthesis ◽  
Receptor Antagonist ◽  
Muscle Cells ◽  
Inhibitory Effect ◽  
Ang Ii ◽  
Β Receptor ◽  
Tgf Β1

The interaction of ANG II with platelet-derived growth factor (PDGF)-BB-induced DNA synthesis was studied in cultured rat aortic smooth muscle cells. PDGF-BB-induced DNA synthesis was delayed (∼6–8 h) by ANG II as shown by a time-course experiment. Losartan, an AT1-receptor antagonist, blocked the transient inhibitory effect of ANG II, whereas the AT2-receptor antagonist PD-123319 had no effect. Autocrine- or paracrine-acting transforming growth factor-β1 (TGF-β1), believed to be a mediator of ANG II-induced inhibitory effects, was not responsible for the delay of PDGF-BB-induced DNA synthesis, because a potent TGF-β1 neutralizing antibody could not reverse this effect of ANG II, nor was the delay of the PDGF-BB effect caused by inhibition of PDGF-β-receptor phosphorylation as shown by Western blot analysis of immunoprecipitated PDGF-β receptor. In conclusion, our results show that ANG II can exert a transient inhibitory effect on PDGF-BB-induced proliferation via the AT1 receptor.

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.

Various cells release a stable small molecule that inhibits endothelium-dependent relaxation

1995 ◽  
Vol 269 (4) ◽  
pp. H1303-H1311
Author(s):  
J. J. Liu ◽  
B. Xie ◽  
P. J. Thurlow ◽  
J. S. Wiley ◽  
J. R. Chen
Keyword(s):  
Smooth Muscle ◽  
Endothelial Cell ◽  
Tumor Cell ◽  
Smooth Muscle Cells ◽  
Cell Line ◽  
Tumor Cell Line ◽  
Muscle Cells ◽  
Cardiac Cells ◽  
Endothelial Cell Line ◽  
Endothelium Dependent Relaxation

Previous studies have shown that neutrophils release a stable factor that inhibits endothelium-dependent relaxation. In the present studies, the effects of supernatants derived from various cells on endothelium-dependent relaxation were studied. Cells were obtained from seven sources: human hematopoietic cells including mononuclear leukocytes (MONO), polymorphonuclear leukocytes (PMNs), and chronic lymphocytic leukemia (CLL) cells; cells of the cardiovascular system including human endothelial cell line ECV304, human smooth muscle cells, and rat myocardial cells; and the tumor cell line HPB. These isolated or cultured cells were incubated for 1 h in Krebs solution to release the factor. The results showed that the supernatants from 10(5) cells/ml of all cells except the tumor cell line HPB produced a potent inhibitory effect on endothelium-dependent relaxation of rat aortic rings in response to acetylcholine and Ca2+ ionophores A23187 and ionomycin but not on endothelium-independent relaxation to nitroprusside and glyceryl trinitrate. When the concentration increased to 10(6) cell/ml, the supernatants from the tumor cell line HPB also slightly but significantly inhibited endothelium-dependent relaxation. The potency order was PMNs = MONO = CLL cells > cardiac cells > smooth muscle cells > the endothelial cell line ECV304 > the tumor cell line HPB. It seems that the hematopoietic cells and the cardiac cells are more active in release of the factor. The effect of this factor was rapid in onset and hard to wash out. A cyclooxygenase inhibitor or a thromboxane A2-prostaglandin H2 receptor antagonist partially but significantly reduced the effect of the factor.(ABSTRACT TRUNCATED AT 250 WORDS)

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