Apigenin inhibits endothelial-cell proliferation in G2/M phase whereas it stimulates smooth-muscle cells by inhibiting P21 and P27 expression

Author(s):  
V�ronique Trochon ◽  
Emmanuel Blot ◽  
Florence Cymbalista ◽  
Carsten Engelmann ◽  
Ruo-Ping Tang ◽  
...  
1987 ◽  
Vol 165 (3) ◽  
pp. 908-913 ◽  
Author(s):  
D P Hajjar ◽  
D B Boyd ◽  
P C Harpel ◽  
R L Nachman

Histidine-rich glycoprotein (HRGP), an alpha-glycoprotein in human plasma that is also present in platelets and macrophages, binds heparin with high affinity and neutralizes its anticoagulant activity. We now report that HRGP specifically inhibits the antiproliferative effect of heparin on arterial smooth muscle cells while other heparinoid-binding proteins do not influence mitogenesis. The multicellular inflammatory response to endothelial injury characterized, in part, by the influx of platelets and macrophages, may be associated with HRGP release into the arterial microenvironment. This release of HRGP may allow smooth muscle cell proliferation and atherogenesis by inhibiting the action of endothelial cell-derived heparinoid substances.


1990 ◽  
Vol 63 (02) ◽  
pp. 291-297 ◽  
Author(s):  
Herm-Jan M Brinkman ◽  
Marijke F van Buul-Worteiboer ◽  
Jan A van Mourik

SummaryWe observed that the growth of human umbilical arterysmooth muscle cells was inhibited by the phospholipase A2 inhibitors p-bromophenacylbromide and mepacrine. Thesefindings suggest that fatty acid metabolism might be integrated in the control mechanism of vascular smooth muscle cell proliferation. To identify eicosanoids possibly involved in this process, we studied both the metabolism of arachidonic acid of these cells in more detail and the effect of certain arachidonic acid metabolites on smooth muscle cells growth. We found no evidence for the conversion of arachidonic acid via the lipoxygenase pathway. In contrast, arachidonic acid was rapidly converted via the cyclooxy-genase pathway. The following metabolites were identified: prostaglandin E2 (PGE2), 6-keto-prostaglandin F1α (6-k-PGF1α), prostaglandin F2α (PGF2α), 12-hydroxyheptadecatrienoic acid (12-HHT) and 11-hydroxyeicosatetetraenoic acid (11-HETE). PGE2 was the major metabolite detected. Arachidonic acid metabolites were only found in the culture medium, not in the cell. After synthesis, 11-HETE was cleared from the culture medium. We have previously reported that PGE2 inhibits the serum-induced [3H]-thymidine incorporation of growth-arrested human umbilical artery smooth muscle cells. Here we show that also 11-HETEexerts this inhibitory property. Thus, our data suggeststhat human umbilical artery smooth muscle cells convert arachidonic acid only via the cyclooxygenase pathway. Certain metabolites produced by this pathway, including PGE2 and 11-HETE, may inhibit vascular smooth muscle cell proliferation.


2000 ◽  
Vol 279 (1) ◽  
pp. C248-C256 ◽  
Author(s):  
Liu Hua Wei ◽  
Aaron T. Jacobs ◽  
Sidney M. Morris ◽  
Louis J. Ignarro

The objectives of this study were to determine whether rat aortic smooth muscle cells (RASMC) express arginase and to elucidate the possible mechanisms involved in the regulation of arginase expression. The results show that RASMC contain basal arginase I (AI) activity, which is significantly enhanced by stimulating the cells with either interleukin (IL)-4 or IL-13, but arginase II (AII) expression was not detected under any condition studied here. We further investigated the signal transduction pathways responsible for AI induction. AI mRNA and protein levels were enhanced by addition of forskolin (1 μM) and inhibited by H-89 (30 μM), suggesting positive regulation of AI by a protein kinase A pathway. Genistein (10 μg/ml) and sodium orthovanadate (Na3VO4; 10 μM) were used to investigate the role of tyrosine phosphorylation in the control of AI expression. Genistein inhibited, whereas Na3VO4enhanced the induction of AI by IL-4 or IL-13. Along with immunoprecipitation and immunoblot analyses, these data implicate the JAK/STAT6 pathway in AI regulation. Dexamethasone (Dex) and interferon (IFN)-γ were investigated for their effects on AI induction. Dex (1 μM) and IFN-γ (100 U/ml) alone had no effect on basal AI expression in RASMC, but both reduced AI induction by IL-4 and IL-13. In combination, Dex and IFN-γ abolished AI induction by IL-4 and IL-13. Finally, both IL-4 and IL-13 significantly increased RASMC DNA synthesis as monitored by [3H]thymidine incorporation, demonstrating that upregulation of AI is correlated with an increase in cell proliferation. Blockade of AI induction by IFN-γ, H-89, or genistein also blocked the increase in cell proliferation. These observations are consistent with the possibility that upregulation of AI might play an important role in the pathophysiology of vascular disorders characterized by excessive smooth muscle growth.


2021 ◽  
pp. 204589402110461
Author(s):  
Yanting Zhu ◽  
Qianqian Zhang ◽  
Xin Yan ◽  
Lu Liu ◽  
Cui Zhai ◽  
...  

Pulmonary arterial hypertension (PAH) is a devastating pulmonary vascular disease, in which the pathogenesis is complicated and unclear. Pulmonary arterial smooth muscle cells (PASMCs) proliferation is a key pathological feature of PAH. It has been shown that ubiquitin-specific protease 7 (USP7) is involved in cancer cell proliferation via deubiquitinating and stabilizing E3 ubiquitin ligase mouse double minute 2 (MDM2). However, the effect of USP7 and MDM2 on platelet derived growth factor (PDGF) -induced PASMCs proliferation is uncertain. This study aims to explore this issue. Our results indicated that PDGF up-regulated USP7 protein expression and stimulated PASMCs proliferation; this was accompanied with the increase of MDM2, forkhead box O4 (FoxO4) reduction and elevation of CyclinD1. While prior transfection of USP7 siRNA blocked PDGF-induced MDM2 up-regulation, FoxO4 down-regulation, increase of CyclinD1 and cell proliferation. Pre-depletion of MDM2 by siRNA transfection reversed PDGF-induced reduction of FoxO4, up-regulation of CyclinD1 and PASMCs proliferation. Furthermore, pre-treatment of cells with proteasome inhibitor MG-132 also abolished PDGF-induced FoxO4 reduction, CyclinD1 elevation and cell proliferation. Our study suggests that USP7 up-regulates MDM2, which facilitates FoxO4 ubiquitinated degradation, and subsequently increases the expression of CyclinD1 to mediate PDGF-induced PASMCs proliferation.


2003 ◽  
Vol 94 (4) ◽  
pp. 1403-1409 ◽  
Author(s):  
A. Cogo ◽  
G. Napolitano ◽  
M. C. Michoud ◽  
D. Ramos Barbon ◽  
M. Ward ◽  
...  

Although it is well known that hypoxemia induces pulmonary vasoconstriction and vascular remodeling, due to the proliferation of both vascular smooth muscle cells and fibroblasts, the effects of hypoxemia on airway smooth muscle cells are not well characterized. The present study was designed to assess the in vitro effects of hypoxia (1 or 3% O2) on rat airway smooth muscle cell growth and response to mitogens (PDGF and 5-HT). Cell growth was assessed by cell counting and cell cycle analysis. Compared with normoxia (21% O2), there was a 42.2% increase in the rate of proliferation of cells exposed to 3% O2 (72 h, P = 0.006), as well as an enhanced response to PDGF (13.9% increase; P = 0.023) and to 5-HT (17.2% increase; P = 0.039). Exposure to 1% O2 (72 h) decreased cell proliferation by 21.0% ( P = 0.017) and reduced the increase in cell proliferation induced by PGDF and 5-HT by 16.2 and 15.7%, respectively ( P = 0.019 and P = 0.011). A significant inhibition in hypoxia-induced cell proliferation was observed after the administration of bisindolylmaleimide GF-109203X (a specific PKC inhibitor) or downregulation of PKC with PMA. Pretreatment with GF-109203X decreased proliferation by 21.5% ( P = 0.004) and PMA by 31.5% ( P = 0.005). These results show that hypoxia induces airway smooth muscle cell proliferation, which is at least partially dependent on PKC activation. They suggest that hypoxia could contribute to airway remodeling in patients suffering from chronic, severe respiratory diseases.


1999 ◽  
Vol 128 (3) ◽  
pp. 673-683 ◽  
Author(s):  
Michiko Asano ◽  
Toshiaki Nakajima ◽  
Kuniaki Iwasawa ◽  
Toshihiro Morita ◽  
Fumitaka Nakamura ◽  
...  

1977 ◽  
Author(s):  
L. A. Harker ◽  
R. Ross ◽  
J. Glomset

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.


1993 ◽  
Vol 61 ◽  
pp. 119
Author(s):  
Megumi Kawanishi ◽  
Hisayuki Ohata ◽  
Kazutaka Momose ◽  
Chikako Uneyama ◽  
Michihito Takahashi ◽  
...  

2001 ◽  
Vol 280 (1) ◽  
pp. H160-H167 ◽  
Author(s):  
Geoffrey G. Emerson ◽  
Steven S. Segal

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.


Sign in / Sign up

Export Citation Format

Share Document