Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The preparation of a proteoglycan (PG) from human aortic intima-media is described. The PG was obtained from intima-media homogenates by differential centrifugation, exclusion chromatography and preparative agarose electrophoresis. Crude or purified preparations of the proteoglycan are capable of forming specific insoluble complexes with LDL, purified or in serum. This product has been labelled lipoprotein-complexing proteoglycan (LCP-3). On agarose and cellulose acetate electrophoresis LCP-3 appears as a single band. However, its glycosaminoglycan (GAG) moiety shows a composition and chromatographic behaviour compatible with hybrid or mixed chains of chondroitin-6-so4, dermatan sulfate and heparin and/or heparan sulfate. The specificity of LCP-3 for LDL disappears when it is treated with testicular hyaluronidase or proteolytic enzymes. Ionic strength, pH, Ca++ and Mg++ modulate the amount of LDL insolubilized. The amino acid composition of the protein from LCP-3 is that of a basic protein(s), perhaps bound covalently through xylose--serine residues to the GAG's. The estimated molecular weight of LCP-3 is 1 to 5 x 10(6) daltons. The presence of LCP-3 to intima-media and its specificity for interacting with LDL at conditions near to physiological ones are suggestive of the role that this type of structure may play in the association of the atherogenic lipoproteins with components of the arterial intima-media.
Atherosclerosis 1980 Mar
PMID:Characterization and properties of a lipoprotein-complexing proteoglycan from human aorta. 736 2

The aim of our study was to investigate the production of hyaluronan (HA) by the intima-media during the sclerotic response to aortic injury with a catheter balloon in the rat. In addition we analyzed, for the first time in this model, the production of a glycoprotein (hyaluronectin, HN) which binds specifically to HA. HA and HN were analyzed in control (D0), 14 (D14) and 28 (D28) days after injury using biochemical and immunohistochemical techniques. Intima-media DNA content and wet weight increased significantly on D14 and declined on D28 (but remained significantly increased in comparison to controls). HA content (median in D0 = 448 ng) increased significantly on D14 (2P < 0.04) and on D28 (2P < 0.02). HN content (median in D0 = 920 ng) increased significantly on D14 (2P < 0.05) but decreased on D28 to return to the control level. On D0 the amount of HN was about 3 times higher than that of HA (median ratio HA/HN = 0.34). The ratio remained unchanged on D14 but significantly increased on D28 (2P < 0.02). HPLC and Western blotting showed no difference between HN extracted from normal aorta and HN extracted from injured aorta at D14. Different isoforms of HN were present in both cases, ranging from 400 to 45 kDa. The HA increase on D14 and D28 was not related to a change in hyaluronidase activity of aortic tissue. Immunohistochemical analysis showed at D0 a small amount of HA around arterial smooth muscle cells (ASMC) in media, at D14 more HA was localized around and between ASMC in media and neointima but at D28 it was localized mainly near the vessel lumen. HN formed all the time (D0, D14 and D28) a continuous layer localized near the vessel lumen. In vitro studies showed that production of HA and HN was stimulated when ASMC proliferate and HA at high concentrations (1-100 micrograms/ml) reduced, in a dose dependent manner, ASMC growth. In conclusion our results show that both neointima formation in vivo and ASMC proliferation in vitro correlated with increased HA and HN production. This suggests that HA and HN are probably involved in the formation of neointima. On the other hand, the finding that HA continued to increase in the aorta when neointima decreased and that high concentrations of HA reduce ASMC proliferation in culture suggest that HA might be involved in the regression of neointima.
Atherosclerosis 1996 Sep 06
PMID:Hyaluronan and hyaluronectin production in injured rat thoracic aorta. 884 51

The formation of atherosclerotic lesions is characterized by invasion of vascular smooth muscle cells (VSMC) into the tunica intima of the arterial wall and subsequently by increased proliferation of VSMC, a process apparently restricted to the intimal layer of blood vessels. Both events are preceded by the pathological overexpression of several growth factors, such as platelet-derived growth factor (PDGF) which is a potent mitogen for VSMC and can induce their chemotaxis. PDGF is generally not expressed in the normal artery but it is upregulated in atherosclerotic lesions. We have previously shown that PDGF-BB specifically stimulates proliferating VSMC to secrete a 340 kDa hyaluronic acid (HA-340). Here, we present evidence regarding the biological functions of this glycan. We observed that HA-340 inhibited the PDGF-induced proliferation of human VSMC in a dose-dependent manner and enhanced the PDGF-dependent invasion of VSMC through a basement membrane barrier. These effects were abolished following treatment of HA-340 with hyaluronidase. The effect of HA-340 on the PDGF-dependent invasion of VSMC coincided with increased secretion of the 72-kDa type IV collagenase by VSMC and was completely blocked by GM6001, a hydroxamic acid inhibitor of matrix metalloproteinases. HA-340 did not exert any chemotactic potency, nor did it affect chemotaxis of VSMC along a PDGF gradient. In human atheromatic aortas, we found that HA-340 is expressed with a negative concentration gradient from the tunica media to the tunica intima and the atheromatic plaque. Our findings suggest that HA-340 may be linked to the pathogenesis of atherosclerosis, by modulating VSMC proliferation and invasion.
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PMID:A 340 kDa hyaluronic acid secreted by human vascular smooth muscle cells regulates their proliferation and migration. 963 43

Few studies have examined the effect of aging on arterial wall response to injury, and the results are discordant. Moreover, the effect of aging on hyaluronan synthesis in injured vessels is unknown. The aim of this present study was to determine the effect of aging on neointima formation and hyaluronan (HA), hyaluronidase and hyaluronectin production in injured rat aorta. Aorta was analysed in sham-operated rats (group D0) and 14 (D14) and 28 (D28) days after injury using biochemical and immunohistochemical techniques. Uninjured aorta of old rats was more thickened than that of young rats; it showed a decreased number of arterial smooth muscle cells (ASMC) and was characterized by HA accumulation in the intima and increased hyaluronidase activity. Intima-media wet weight was significantly increased in young rats at D14 and D28 but remained unchanged in old rats. DNA content was significantly enhanced at D14 in both young and old rats. DNA decreased slightly in young rats at D28 but significantly in old rats to return to control level. HA content and hyaluronidase activity in the intima-media were markedly increased in young rats at D14 (+148% and +116% respectively) but slightly in old rats (+23% and +15% respectively). Both HA and hyaluronidase activity continued to increase at D28, but remained more produced in young rats. The immunohistochemical analysis showed the formation of a thickened neointima in young rats, which was associated with strong expression of HA and HN. Neointima of old rats was reduced; it also showed strong expression of HA and HN but their distributions were different from those observed in neointima of young rats. In conclusion, aorta of old rats showed an increased amount of HA in the intima and elevated activity of hyaluronidase. Injury induced formation of a significant neointima in young rats but not in old rats. This was correlated with more HA and hyaluronidase production in injured aorta of young rats. As HA is considered to increase extracellular matrix space and to promote ASMC proliferation and migration, our findings suggest that HA may be implicated in intima thickening with age and after injury.
Atherosclerosis 1998 May
PMID:Effect of aging on neointima formation and hyaluronan, hyaluronidase and hyaluronectin production in injured rat aorta. 967 71

The accumulation of hyaluronan (HA) and the HA-binding proteoglycan versican around smooth muscle cells in lesions of atherosclerosis suggests that together these molecules play an important role in the events of atherogenesis. In this study we have examined the formation of HA- and versican-rich pericellular matrices by human aortic smooth muscle cells in vitro, using a particle-exclusion assay, and the role of the pericellular matrix in cell proliferation and migration. The structural dependence of the pericellular matrix on HA can be demonstrated by the complete removal of the matrix with Streptomyces hyaluronidase. The presence of versican in the pericellular matrix was confirmed immunocytochemically. By electron microscopy, the cell coat was seen as a tangled network of hyaluronidase-sensitive filaments decorated with ruthenium red-positive proteoglycan granules. Ninety percent of migrating cells in wounded cultures, and virtually all mitotic cells, displayed abundant HA- and versican-rich coats. Time-lapse video imaging revealed that HA- and versican-rich pericellular matrix formation is dynamic and rapid, and coordinated specifically with cell detachment and mitotic cell rounding. HA oligosaccharides, which inhibit the binding of HA to the cell surface and prevent pericellular matrix formation, significantly reduced proliferation and migration in response to platelet-derived growth factor, whereas larger HA fragments and high molecular weight HA had no effect. Treatment with HA oligosaccharides also led to changes in cell shape from a typical fusiform morphology to a more spread and flattened appearance. These data suggest that organization of HA- and versican-rich pericellular matrices may facilitate migration and mitosis by diminishing cell surface adhesivity and affecting cell shape through steric exclusion and the viscous properties of HA proteoglycan gels.
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PMID:Formation of hyaluronan- and versican-rich pericellular matrix is required for proliferation and migration of vascular smooth muscle cells. 1019 29

Hyaluronan (HA) is a glycosaminoglycan found in greatest amounts in the extra-cellular matrix of loose connective tissue. HA has been shown to be closely involved in arterial smooth muscle cell (ASMC) proliferation and migration. No studies have examined the degradation of HA in the vessel wall during proliferation of ASMC. The aim of our study was to determine whether HA degradation was modulated in the injured rat aorta with a catheter balloon. To evaluate HA degradation we quantified the activity of the enzyme which degrades HA (hyaluronidase) and determined HA molecular mass in the aorta. Aorta was analyzed in sham operated aorta (D0) and 14 (D14) days after injury. Intima-media wet weight and DNA content, a parameters reflecting ASMC response to injury, were significantly increased at D14 (+35.5 and +40.8%). HA increased at D14 (+87%) and was mainly expressed in the neointima. Hyaluronidase activity also increased in the aorta at D14 (+25.5%). In the normal aorta, HA was mainly present in a high molecular mass form (2000 kDa). Two low molecular mass HA were also detected (29 and <20 kDa). At D14, the form of 2000 kDa was dramatically increased in comparison to that in normal aorta. In addition, the injured aorta contained a large number of low molecular mass form of HA. To know whether hyaluronidase production in the injured aorta was associated with appearance of new isoforms, we determined the molecular mass of this enzyme. Only one form of hyaluronidase (78 kDa) was present in both groups (D0 and D14). In conclusion, the proliferative response of ASMC to injury in the rat was found to be associated with increased HA degradation.
Atherosclerosis 2001 Aug
PMID:The fibroproliferative response of arterial smooth muscle cells to balloon catheter injury is associated with increased hyaluronidase production and hyaluronan degradation. 1147 28

It has been demonstrated previously that administration of high levels of high molecular mass hyaluronan (hyaluronic acid, HA) to rats was able to reduce in a significant way neointima formation in the injured arteries. In the present study, our aim was to verify whether small forms of HA (4-16 saccharides) are still able to reduce the proliferative response of ASMC to aortic injury. Treated rats received a total of 8 injections of a fixed dose of HA fragments (27 mg/kg rat contained in a volume of 550 microl). Two injections were given on the day of balloon catheter injury (BCI): one, intravenous, 10 min before BCI and one, subcutaneous, immediately after the BCI. The others injections (subcutaneous) were at 2, 4, 6, 8, 10 and 12 days after BCI. Control rats received an equivalent volume of the dissolving buffer containing only hyaluronidase, which has been destroyed before injection to rats. Neointima formation was analysed 14 days after the BCI. Intima-media wet weight and DNA content were significantly reduced in rats receiving HA fragments in comparison to controls (2P=0.01 for wet weight and 0.03 for DNA). This finding was confirmed by the histomorphometric study which showed that both neointima area and the ratio neointima/neointima+media were significantly decreased in treated rats (2P=0.03 for intima area and 0.049 for the ratio). Our data showed thus and for the first time that administration of HA fragments with a very low molecular mass (4-16 saccharides) reduces the proliferative reaction of aorta to injury in vivo. In conclusion, HA fragments, which are components with an excellent safety profile, may offer hope for the prevention of restenosis after angioplasty.
Atherosclerosis 2003 Nov
PMID:Inhibition of arterial cells proliferation in vivo in injured arteries by hyaluronan fragments. 1464 1

Inflammation and increased capillary permeability is a significant aspect of the pathogenesis of many diseases including atherosclerosis. L-type calcium channel blockers (CCB) are commonly used as cardiovascular drugs. Amlodipine, lacidipine, and nicardipine were evaluated for anti-inflammatory activity on the paw oedema produced by carrageenan. The effect of these drugs was compared with the activity of indomethacin. Their effects on vascular permeability were also tested by hyaluronidase-induced capillary permeability. In our animal experiments, amlodipine decreased the carrageenan-induced paw oedema at doses of 1, 3, and 6 mg kg(-1) by 27.3%, 43.7%, and 67.3% four hour after carrageenan administration; the same doses of lacidipine and nicardipine decreased paw oedema by 37.1%, 55.6%, 76.4%, 11.2%, 31.0%, 91%; and indomethacin decreased oedema by 38.2% at a dose of 6 mg kg(-1). Lacidipine significantly inhibited the hyaluronidase-induced increase in capillary permeability at doses of 1, 3, and 6 mg kg(-1) compared with the control group. However, amlodipine and nicardipine significantly inhibited the hyaluronidase-induced increase in capillary permeability at 3 and 6 mg kg(-1) doses. A 6 mg kg(-1) dose of indomethacin significantly decreased the capillary permeability which was increased by hyaluronidase. These results suggest that CCBs can be efficient anti-inflammatories, and can also significantly decrease capillary permeability.
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PMID:Effects of calcium channel blockers on hyaluronidase-induced capillary vascular permeability. 1870 32

Changes in the extracellular matrix organization within vascular walls are critical events in the process of atherosclerosis including diabetic macroangiopathy. Here, we examined whether glucose can directly modulate connective tissue reorganization by human vascular smooth muscle cells (VSMCs). Using a collagen gel contraction (CGC) assay, we demonstrated that in comparison with normal glucose concentration (5 mM), high glucose concentration (25 mM) inhibits the efficacy of VSMCs to contract collagen gels. With human genome microarrays, we showed a significant increase in the expression of hyaluronan synthase 2 (HAS2) by VSMCs in hyperglycemic conditions. The finding was verified with quantitative real-time polymerase chain reaction, which also revealed that the expression of the other hyaluronan synthesizing enzymes, HAS1 and HAS3, was stimulated concomitantly. A corresponding increase was observed in hyaluronan (HA) production. Treatment of VSMCs either with hyaluronidase or with 4-methylumbelliferone, an inhibitor of HA synthesis, partially restored the diminished CGC efficacy of VSMCs in hyperglycemic conditions. In conclusion, high glucose concentration stimulated HA synthesis by VSMCs and modulated their ability to reorganize collagen-rich matrix. Because HA is known to enhance the development of atherosclerosis and restenosis after percutaneous coronary interventions, our study provides a new potential mechanism whereby hyperglycemia leads to disturbed vascular remodeling in diabetic patients through stimulation of HA synthesis.
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PMID:Hyperglycemic conditions modulate connective tissue reorganization by human vascular smooth muscle cells through stimulation of hyaluronan synthesis. 2048 39

Vascular integrity or the maintenance of blood vessel continuity is a fundamental process regulated, in part, by the endothelial glycocalyx and cell-cell junctions. Defects in endothelial barrier function are an initiating factor in several disease processes including atherosclerosis, ischemia/reperfusion, tumor angiogenesis, cancer metastasis, diabetes, sepsis and acute lung injury. The glycosaminoglycan, hyaluronan (HA), maintains vascular integrity through endothelial glycocalyx modulation, caveolin-enriched microdomain regulation and interaction with endothelial HA binding proteins. Certain disease states increase hyaluronidase activity and reactive oxygen species (ROS) generation which break down high molecular weight HA to low molecular weight fragments causing damage to the endothelial glycocalyx. Further, these HA fragments can activate specific HA binding proteins upregulated in vascular disease to promote actin cytoskeletal reorganization and inhibition of endothelial cell-cell contacts. This review focuses on the crucial role of HA in vascular integrity and how HA degradation promotes vascular barrier disruption.
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PMID:Hyaluronan regulation of vascular integrity. 2225 99


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