Differential Effects of Sodium Spirulan on the Secretion of Fibrinolytic Proteins from Vascular Endothelial Cells: Enhancement of Plasminogen Activator Activity

Biological & Pharmaceutical Bulletin

Shimada

Fujiwara

et al. 2005

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Proteoglycans (PGs) are macromolecules that are composed of a core protein and one or more glycosaminoglycan (GAGs) side chains in a common feature. 1) In the vascular tissue, PGs are involved in the regulation of vascular properties such as permeability, lipid metabolism, hemostasis, thrombosis, and extracellular matrix assembly. [2][3][4][5] In addition, PGs influence the regulation of vascular endothelial and smooth muscle cell function mediated by growth factors 6) and cytokines. 7) There are two types of PGs classified by the structure of GAG chains: one is heparan sulfate PGs (HSPGs) and the other is chondroitin/dermatan sulfate PGs (CS/DS PGs). Vascular endothelial cells predominantly synthesize and secrete a large HSPG, perlecan,8) and a small CS/DS PG, biglycan. 9)Perlecan exhibits antithrombin activity through the activation of antithrombin III 10) by heparin-like sequences in the heparan sulfate chains.11) On the other hand, the antithrombin activity of biglycan is achieved by the activation of heparin cofactor II by the dermatan sulfate chains.12) It is therefore suggested that PGs synthesized and secreted by vascular endothelial cells contribute to local anticoagulant activity on the endothelium.Sodium spirulan (Na-SP) is a sulfated polysaccharide isolated as an antiviral agent from a hot water extract of the blue-green alga Spirulina platensis. 13,14) On the other hand, Na-SP exhibits antithrombin activity in vitro in a fashion different from heparin, 15) suggesting that Na-SP may be an agent that can control anticoagulant activity in the blood. In addition, we found that Na-SP enhances the fibrinolytic activity of the cells through inhibition of plasminogen activator inhibitor-1 secretion.16) This indicates that Na-SP can modulate the anticoagulant and fibrinolytic properties of vascular endothelial cells. We hypothesized that Na-SP may influence the metabolism of endothelial PGs, since heparin has a stimulatory effect on the release of PGs from vascular endothelial cells.17) It was shown that Na-SP stimulates the endothelial PG release as does heparin 18) ; the stimulatory effect requires both the sulfate group and a sodium ion. 19) However, the type(s) of endothelial PGs whose release is stimulated by Na-SP has not been identified yet. In the present study, we suggest that Na-SP-releasable PGs in vascular endothelial cells are both perlecan and biglycan with the intact structure, although the core proteins may be partially degraded. MATERIALS AND METHODSMaterials Vascular endothelial cells derived from bovine aorta were purchased from Dainippon Pharmaceutical (Osaka, Japan). Na-SP was purified as described previously.1,2) Dulbecco's modified Eagle's medium and fetal bovine serum were from Nissui Pharmaceutical (Tokyo, Japan) and Equitech-Bio (Kerrville, TX, U.S.A.), respectively. ASF 301 medium was from Ajinomoto (Tokyo, Japan); tissue culture dishes and plates were from Asahi Technoglass (Chiba, Japan Sodium spirulan (Na-SP) is a sulfated polysaccharide isolated from the blue-green alga Spiruli...

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 96%

Proteoglycans Released from Cultured Bovine Aortic Endothelial Cell Layers by Sodium Spirulan Are Both Perlecan and Biglycan

Biological & Pharmaceutical Bulletin

Shimada

Fujiwara

et al. 2005

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“…11) In addition, the effects of Na-SP on vascular endothelial cell functions, including inhibition of the proliferation, 24) inhibition of the secretion of plasminogen activator inhibitor type 1 12) and stimulation of the release of proteoglycans, 13) disappear after desulfation. It has been shown that several biological activities of SCA also require the sulfate group.…”

Section: Discussionmentioning

confidence: 99%

“…11) In vascular endothelial cells, Na-SP elevates the fibrinolytic activity of vascular endothelial cells through inhibition of the secretion of plasminogen activator inhibitor type 1. 12) In addition, Na-SP promotes the secretion of anticoagulant proteoglycans 13) such as perlecan and biglycan, 14) as well as exhibiting an antithrombin activity through activation of heparin cofactor II. 15,16) We hypothesized that CA or SCA may inhibits the proliferation of vascular smooth muscle cell proliferation, as does natural or semi-synthetic polysaccharides, including Na-SP, heparin, 17) pentosan polysulfate 18) and fucoidan.…”

mentioning

confidence: 99%

Inhibition of Cultured Bovine Aortic Smooth Muscle Cell Proliferation by Colominic Acid

Biological & Pharmaceutical Bulletin

Yamaguchi²,

Hayashi

et al. 2005

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Colominic acid (CA) is an a2,8-linked polymer of sialic acid, originally isolated from capsular Escherichia coli K1. 2) have several biological activities including antiviral activities, [3][4][5] inhibition of the cytotoxic action of bee and snake venom, 6) inhibition of P-selectin-dependent macrophage infiltration in the glomeruli in experimental rat crescentic glomerulonephritis 7) and inhibition of fertilization of mouse gametes. 8)Atherosclerosis is the principal vascular lesion in the pathogenesis of myocardial and cerebral infarction, which is initiated by vascular endothelial cell damage followed by an intimal hyperplasia of vascular smooth muscle cells. 9) Although the pathogenesis of atherosclerosis is not simple, inhibition of arterial smooth muscle cell proliferation is one of the effective strategies to prevent atherosclerosis.We have investigated the effects of sodium spirulan (Na-SP), a sulfated polysaccharide isolated from the blue-green alga Spirulina platensis 10) on vascular endothelial and smooth muscle cell functions, and found that the polysaccharide potently inhibits the proliferation of vascular smooth muscle cells.11) In vascular endothelial cells, Na-SP elevates the fibrinolytic activity of vascular endothelial cells through inhibition of the secretion of plasminogen activator inhibitor type 1.12) In addition, Na-SP promotes the secretion of anticoagulant proteoglycans 13) such as perlecan and biglycan, 14) as well as exhibiting an antithrombin activity through activation of heparin cofactor II. 15,16) We hypothesized that CA or SCA may inhibits the proliferation of vascular smooth muscle cell proliferation, as does natural or semi-synthetic polysaccharides, including Na-SP, heparin, 17) pentosan polysulfate 18) and fucoidan.19) The present study was undertaken to examine this hypothesis using a culture system of bovine aortic smooth muscle cells. It was found that both CA and SCA moderately inhibit the proliferation of the cells without nonspecific cell damage. MATERIALS AND METHODS MaterialsVascular smooth muscle cells obtained from bovine aorta were a gift from Professor Yasuo Suda (Graduate School of Science and Engineering, Kagoshima University, Kagoshima, Japan). Dulbecco's modified Eagle's medium (DMEM) and fetal bovine serum were from Nissui Pharmaceutical (Tokyo, Japan) and MP Biomedicals (Irvine, CA, U.S.A.), respectively. Tissue culture plates and dishes were obtained from Iwaki (Chiba, Japan). H]thymidine (3.3 TBq/mmol) was from Parkin Elmer Life Sciences (Boston, MA, U.S.A.). Lactate dehydrogenase kit was from Wako Pure Chemical (Osaka, Japan). CA 20) (M r ca. 17000) and SCA 2) (M r ca. 22000) containing sulfur of 13.4% were isolated from capsular Escherichia coli K1 as sodium salt of an a2,8-linked homopolymer of N-acetylneuraminic acid with or without sulfation. Na-SP and Ca-SP were isolated and purified from the blue-green alga Spirulina platensis as described previously. 10,21,22) Heparin derived from porcine intestine (M r ca. 10000) was purchased from Sigma (St Louis...

“…4) Na-SP enhances the fibrinolytic activity in the liquid phase of cultured human coronary endothelial cells through inhibition of plasminogen activator inhibitor type 1 secretion. 5) Recent study has shown that Na-SP is a potent inhibitor of cultured vascular smooth muscle cell proliferation. 6) Those results indicate that Na-SP has anticoagulant, fibrinolytic, and antiatherogenic properties in vitro.…”

Section: Introductionmentioning

confidence: 99%

Stimulation of Proteoglycan Release from Cultured Vascular Endothelial Cell Layers by Sodium Spirulan

Kaji

Shimada

JOURNAL OF HEALTH SCIENCE

et al. 2004

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Our previous study suggested that sodium spirulan (Na-SP) stimulated the release of proteoglycans from cultured vascular endothelial cell layers. In the present study, we characterized the stimulatory effect of Na-SP on endothelial proteoglycan release from the viewpoint of the Na-SP structure. The following results were obtained: Na-SP is a potent stimulator of endothelial proteoglycan release. The stimulatory effect of Na-SP disappears with desulfation or removal of sodium ion. Depolymerized Na-SPs (M r ~14700 or greater) also exhibits stimulatory effects as does Na-SP (M r ~220000). The stimulation occurs more potently in endothelial cells than in vascular smooth muscle cells. Therefore it is suggested that the stimulatory effect of Na-SP on proteoglycan release requires both the sulfate group and sodium ion, and the effect is achieved by an active structure in the molecule which interacts particularly with the endothelial cell extracellular matrix.