Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.2.2.7 (heparinase)
 1,270 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bradykinin is a potent inflammatory mediator that induces vasodilation, vascular leakage, and pain sensations. This short-lived peptide hormone is liberated from its large precursor protein high molecular weight kininogen (HK) through the contact system cascade involving coagulation factor XII and plasma kallikrein. Although bradykinin release is well established in vitro, the factors and mechanisms controlling bradykinin generation in vivo are still incompletely understood. In this study we demonstrate that binding of HK to glycosaminoglycans (GAGs) of the heparan and chondroitin sulfate type efficiently interferes with bradykinin release in plasma and on endothelial surfaces. Proteolytic bradykinin production on endothelial cells is restored following degradation of cell surface GAG through heparinase. Alternatively, application of HK fragments D3 or light chain, which compete with uncleaved HK for cell binding, promote kininogen proteolysis and bradykinin release. Intravital microscopy revealed that HK fragments increase bradykinin-mediated mesentery microvascular leakage. Topical application of D3 or light chain enhanced bradykinin generation and edema formation in the mouse skin. Our results demonstrate that bradykinin formation is controlled by HK binding to and detachment from GAGs. Separation of the precursor from cell surfaces is a prerequisite for its efficient proteolytic processing. By this means, fragments arising from HK processing propagate bradykinin generation, revealing a novel regulatory level for the kallikrein-kinin system.
J Immunol 2005 Sep 01
PMID:Local bradykinin formation is controlled by glycosaminoglycans. 1611 31

Heparanase has been previously associated with the metastatic potential, inflammation, and angiogenesis of tumor cells. Heparanase activity has been detected by means of UV absorption, radiolabeled substrates, electrophoretic migration, and heparan sulfate affinity assays. However, those methods have proven to be somewhat problematic with regards to application to actual biological samples, the accessibility of the immobilized substrates, experimental sensitivity, and the separation of degraded products. Rather than focusing on heparanase activity, then, we have developed a rapid, alternative colorimetric heparinase assay, on the basis of the recent finding that sulfated disaccharides generated from heparin by bacterial heparinase exhibit biological properties comparable to those from heparan sulfate by mammalian heparanase. In this study, the concentrations of porcine heparin and bacterial heparinase I were determined using a Sigma Diagnostics Kit. Morus alba was selected as a candidate through this assay system, and an inhibitor, resveratrol, was purified from its methanol extract. Its anti-metastatic effects on the pulmonary metastasis of murine B16 melanoma cells were also evaluated. Our findings suggest that this assay may prove useful as a diagnostic tool for heparinase inhibition, as an alternative anti-metastatic target.
Life Sci 2006 Sep 20
PMID:Colorimetric heparinase assay for alternative anti-metastatic activity. 1680 78

Burkitt's lymphoma (BL) is a B-cell malignancy associated with the Epstein-Barr virus (EBV). Mounting evidence has implicated heparan sulfate proteoglycans and heparan sulfate-like glycosaminoglycans (HSGAGs) in the initiation, severity, and progression of the malignancy. The importance of HSGAGs in regulating BL cell growth was therefore examined. Extracellular exogenous heparin inhibited cell growth >30%, while heparin internalized with poly(beta-amino ester)s promoted proliferation up to 58%. The growth-modulating effects of heparin and internalized heparin were dependent on cell surface HSGAGs, PI3K, and Erk/Mek. Treatment of cells with protamine sulfate or with heparinases potently inhibited proliferation, with the greatest effects induced by heparinase I. Cell surface HSGAGs therefore play an important role in regulating BL proliferation and may offer a potential target for therapeutic intervention.
Biochem Biophys Res Commun 2006 Sep 29
PMID:Heparin localization and fine structure regulate Burkitt's lymphoma growth. 1690 41

Herpes simplex virus type 1 (HSV-1) infection of the corneal stroma remains a major cause of blindness. Primary cultures of corneal fibroblasts (CF) were tested and found susceptible to HSV-1 entry, which was confirmed by deconvolution imaging of infected cells. Plaque assay and real-time PCR demonstrated viral replication and hence a productive infection of CF by HSV-1. A role for glycoprotein D (gD) receptors in cultured CF was determined by gD interference assay. Reverse transcription-PCR analysis indicated expression of herpesvirus entry mediator and 3-O-sulfated (3-OS) heparan sulfate (HS)-generating enzyme 3-O sulfotransferase 3 (3-OST-3) but not nectin-1 or nectin-2. Subsequently, HS isolated from these cells was found to contain two distinct disaccharides (IdoUA2S-AnMan3S and IdoUA2S-AnMan3S6S) that are representative of 3-OST-3 activity. The following lines of evidence supported the important role of 3-OS HS as the mediator of HSV-1 entry into CF. (i) Blockage of entry was observed in CF treated with heparinases. The same enzymes had significantly less effect on HeLa cells that use nectin-1 as the entry receptor. (ii) Enzymatic removal of cell surface HS also removed the major gD-binding receptor, as evident from the reduced binding of gD to cells. (iii) Spinoculation assay demonstrated that entry blockage by heparinase treatment included the membrane fusion step. (iv) HSV-1 glycoprotein-induced cell-to-cell fusion was inhibited by either prior treatment of cells with heparinases or by HS preparations enriched in 3-OS HS. Taken together, the data in this report provide novel information on the role of 3-OS HS in mediating infection of CF, a natural target cell type.
J Virol 2006 Sep
PMID:Role for 3-O-sulfated heparan sulfate as the receptor for herpes simplex virus type 1 entry into primary human corneal fibroblasts. 1694 May 9

Expression of angiogenic cytokines like vascular endothelial growth factor is enhanced by hypoxia. We tested the hypothesis that decreased oxygen levels up-regulate the angiogenic factor secretoneurin. In vivo, muscle cells of mouse ischemic hind limbs showed increased secretoneurin expression, and inhibition of secretoneurin by a neutralizing antibody impaired the angiogenic response in this ischemia model. In a mouse soft tissue model of hypoxia, secretoneurin was increased in subcutaneous muscle fibers. In vitro, secretoneurin mRNA and protein were up-regulated in L6 myoblast cells after exposure to low oxygen levels. The hypoxia-dependent regulation of secretoneurin was tissue specific and was not observed in endothelial cells, vascular smooth muscle cells, or AtT20 pituitary tumor cells. The hypoxia-dependent induction of secretoneurin in L6 myoblasts is regulated by hypoxia-inducible factor-1alpha, since inhibition of this factor using si-RNA inhibited up-regulation of secretoneurin. Induction of secretoneurin by hypoxia was dependent on basic fibroblast growth factor in vivo and in vitro, and inhibition of this regulation by heparinase suggests an involvement of low-affinity basic fibroblast growth factor binding sites. In summary, our data show that the angiogenic cytokine secretoneurin is up-regulated by hypoxia in muscle cells by hypoxia-inducible factor-1alpha- and basic fibroblast growth factor-dependent mechanisms.
FASEB J 2007 Sep
PMID:Hypoxia up-regulates the angiogenic cytokine secretoneurin via an HIF-1alpha- and basic FGF-dependent pathway in muscle cells. 1750 77

The heparan sulfate proteoglycan syndecan-1 is expressed by myeloma cells and shed into the myeloma microenvironment. High levels of shed syndecan-1 in myeloma patient sera correlate with poor prognosis and studies in animal models indicate that shed syndecan-1 is a potent stimulator of myeloma tumor growth and metastasis. Overexpression of extracellular endosulfatases, enzymes which remove 6-O sulfate groups from heparan sulfate chains, diminishes myeloma tumor growth in vivo. Together, these findings identify syndecan-1 as a potential target for myeloma therapy. Here, 3 different strategies were tested in animal models of myeloma with the following results: (1) treatment with bacterial heparinase III, an enzyme that degrades heparan sulfate chains, dramatically inhibited the growth of primary tumors in the human severe combined immunodeficient (SCID-hu) model of myeloma; (2) treatment with an inhibitor of human heparanase, an enzyme that synergizes with syndecan-1 in promoting myeloma progression, blocked the growth of myeloma in vivo; and (3) knockdown of syndecan-1 expression by RNAi diminished and delayed myeloma tumor development in vivo. These results confirm the importance of syndecan-1 in myeloma pathobiology and provide strong evidence that disruption of the normal function or amount of syndecan-1 or its heparan sulfate chains is a valid therapeutic approach for this cancer.
Blood 2007 Sep 15
PMID:The syndecan-1 heparan sulfate proteoglycan is a viable target for myeloma therapy. 1753 13

Exposure of animals to hyperoxia decreases lung VEGF mRNA expression concomitant with an acute increase in VEGF protein within the epithelial lining fluid (ELF). The VEGF concentration in ELF is in excess of that found in the plasma, leading to the hypothesis that hyperoxia stimulates the release of VEGF protein from stores within the extracellular matrix. To test this hypothesis in a cell culture system, we exposed A549 cells to 95% O(2) (Ox) for 48 h followed by recovery in room air (RA) for 24 h. We found that Ox increased VEGF protein two- to threefold within the medium at 48 h of exposure and during recovery. Heparin clearing revealed the medium to contain a 50/50 mixture of the heparin-binding (VEGF(165)) and heparin-nonbinding (VEGF(121)) proteins and that Ox increased both proteins equally. Transcriptional activation of VEGF seems unlikely to explain the increase in VEGF protein, as expression of full-length and splice variant VEGF mRNA was unchanged by hyperoxia. Analysis of cell-associated VEGF proteins found that Ox increased the expression of VEGF(121) and VEGF(165) proteins. Blocking binding sites with exogenous heparin enhanced VEGF protein in the medium from RA-grown cells, whereas heparinase digestion of bound VEGF revealed a greater reserve of VEGF protein in RA cells. Collectively these findings indicate that hyperoxia enhances the expression of VEGF(121/165) proteins and facilitates the release of VEGF(165) from cell-associated stores. Increases in VEGF in ELF may represent an adaptive response fostering cell survival and type II cell proliferation in O(2)-induced lung injury.
Free Radic Biol Med 2007 Sep 01
PMID:Hyperoxia enhances VEGF release from A549 cells via post-transcriptional processes. 1766 48

Thrombin induces Ca(2+) transients and subsequent nitric oxide (NO) production in vascular endothelial cells. Thrombin cleaves protease-activated receptors, resulting in activation of intracellular signals, but it is not clarified how the extracellular thrombin stays around the cells to exert its enzyme activities. This study aimed to investigate the possible involvement of heparin sulfate proteoglycan (HSPG) in the effects of thrombin on vascular endothelium. Heparinase III completely removed the polysaccharide chain of HSPG in bovine aortic endothelial cells (BAECs). Thrombin induced Ca(2+) transients in control BAECs, but not in heparinase III-treated BAECs. In contrast, ATP induced Ca(2+) transients both in control and heparinase III-treated BAECs. Thrombin that was pre-incubated with heparin also failed to induced Ca(2+) transients in BAECs. Furthermore, thrombin-induced NO production, as assessed with DAF-2 fluorescence, was suppressed in heparinase III-treated BAECs and by the pre-incubation of thrombin with heparin. ATP-induced NO production was, however, not affected in heparinase III-treated BAECs. These results indicate that it is essential for thrombin to bind to the polysaccharide chain of HSPG for inducing Ca(2+) transients and NO production in BAECs.
Thromb Haemost 2008 Sep
PMID:Heparan sulfate proteoglycan is essential to thrombin-induced calcium transients and nitric oxide production in aortic endothelial cells. 1876 50

Although the glycocalyx has been implicated in wall shear stress (WSS) mechanotransduction, the role of glycocalyx components in nitric oxide (NO) and reactive oxygen species (ROS) production remains unclear. Here, we tested the hypothesis that glycocalyx is implicated in both endothelial NO and O(2)(-) production. Specifically, we evaluated the role of hyaluronic acid (HA), heparan sulfate (HS), and sialic acid (SA) in NO and O(2)(-) mechanotransduction. Twenty-seven ex vivo porcine superficial femoral arteries were incubated with heparinase III, hyaluronidase, or neuraminidase, to remove HS, HA, or SA, respectively, from glycocalyx. The arteries were then subjected to steady-state flow and the effluent solution was measured for nitrites and the vessel diameter was tracked to quantify the degree of vasodilation. Our results show that removal of HA decreased both nitrites and vasodilation, and tempol treatment had no reversing effect. Degradation of HS proteoglycans decreased NO bioavailability through an increase in O(2)(-) production as indicated by fluorescent signals of dihydroethidium (DHE) and its area fraction (209+/-24% increase) and also removed extracellular O(2)(-) dismutase (ecSOD) (67+/-9% decrease). The removal of SA also increased O(2)(-) production as indicated by DHE fluorescent signals (86+/-17% increase) and the addition of tempol, a mimic O(2)(-) scavenger, restored both NO availability and vasodilation in both heparinase- and neuraminidase-treated vessels. This implies that HS and SA are not directly involved in WSS-mediated NO production. This study implicates HA in WSS-mediated NO mechanotransduction and underscores the role of HS and SA in ROS regulation in vessel walls in response to WSS stimulation.
Free Radic Biol Med 2009 Sep 01
PMID:Role of glycocalyx in flow-induced production of nitric oxide and reactive oxygen species. 1950 Jun 64

In the present study, heparin immobilized, multifunctional gold nanoparticles (AuNPs) were developed as a new class of theragnostic nanomaterials for metastatic cancer cell imaging and apoptosis. AuNPs were surface modified with fluorescent dye labeled heparin molecules to detect a metastatic stage of cancer cells that over-express heparin-degrading enzymes. The heparin immobilized AuNPs exhibited enhanced fluorescence signals by specific cleavage of heparin molecules from the surface of AuNPs by heparinase or heparanase secreted from metastatic cancer cells. In addition, heparin immobilized AuNPs that were additionally tethered with RGD peptides on the surface demonstrated highly specific apoptotic activities for selective cancer cells over-expressing RGD receptors on the membrane, revealing that internalized heparin within cells clearly triggered an apoptotic event. These results suggest that heparin immobilized AuNPs can be usefully exploited for optical imaging agents for metastatic tumors as well as therapeutic cancer treatment.
Biomaterials 2010 Sep
PMID:Heparin immobilized gold nanoparticles for targeted detection and apoptotic death of metastatic cancer cells. 2053 79


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