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

The localization of hyaluronic acid (HA), glial hyaluronate-binding protein (GHAP), and chondroitin sulfate (CS) proteoglycan was compared in cryostat sections of rat spinal cord. HA, GHAP, and CS proteoglycan were similarly distributed in white matter where they surrounded myelinated axons. In gray matter, large motoneurons were surrounded by a rim of reaction product in sections stained for HA and CS proteoglycan. GHAP immunoreactivity as well as HA had disappeared in hyaluronidase-digested sections, while CS proteoglycan immunoreactivity was not abolished under these conditions.
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PMID:The extracellular matrix of rat spinal cord: a comparative study on the localization of hyaluronic acid, glial hyaluronate-binding protein, and chondroitin sulfate proteoglycan. 137 37

A large proteoglycan (365 kDa), identified with monoclonal antibodies raised against chondroitin sulfate, was isolated from human brain. The isolation required anion-exchange chromatography followed by gel filtration through a Sephacryl S-500 column. The proteoglycan bound specifically to [3H]hyaluronate (HA). The binding was not reduced by high salt concentrations (up to 4 M) and was inhibited at low pH (< 4.0). The binding was inhibited by the octamer and decamer (but not the hexamer) oligosaccharides of HA. Limited proteolysis of the proteoglycan gave rise to a relatively stable polypeptide (80 kDa). The amino-terminal sequence of the 80-kDa polypeptide was identical to the cDNA-derived amino-terminal sequence of versican, a large human fibroblast proteoglycan. A monoclonal antibody raised against bovine proteoglycans and recognizing the versican core protein reacted by immunoblotting with the proteoglycan isolated from human brain. The antibody was used to localize the proteoglycan in acetone-fixed cryostat sections of bovine spinal cord. The localization of the proteoglycan in the central nervous system was identical to that previously reported for glial hyaluronate-binding protein (GHAP), a 60-kDa glycoprotein of the brain extracellular matrix (ECM). However, a major difference was observed with respect to the sensitivity of the two antigens to hyaluronidase. As previously reported, GHAP was released from the tissue by hyaluronidase digestion, whereas the proteoglycan persisted under these conditions. We conclude that the protein-hyaluronate aggregates in brain ECM contain both GHAP and versican, that GHAP is only retained in the ECM by its interaction with hyaluronate, and that the proteoglycan is anchored in some other manner and probably connects cell surfaces with the ECM since it was not released by hyaluronidase digestion.
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PMID:Isolation of a large aggregating proteoglycan from human brain. 142 26

Monoclonal antibodies were raised against human glial hyaluronate-binding protein (GHAP), a major CNS-specific glycoprotein known to bind hyaluronate in vitro. Frozen sections of dog and human spinal cord were digested with Streptomyces hyaluronidase in order to ascertain whether GHAP is bound to hyaluronate in vivo. Digestion with hyaluronidase, prior to staining of the sections by conventional indirect immunofluorescence, led to a drastic reduction in the intensity of the staining reaction. Chondroitinase ABC (protease-free) was also effective in bringing about the release of GHAP from tissue sections. This enzyme also degrades hyaluronate. The effects of the chondroitinase were completely reversed by the addition of 1 mM Zn2+, a known inhibitor of this enzyme. The intact protein was released into the soluble fraction of human brain homogenates by testicular hyaluronidase. An immunoreactive species of 70 kD was released into the soluble fraction of dog spinal cord homogenates by Streptomyces hyaluronidase. Dog GHAP was isolated from spinal cord by means of ion exchange and affinity chromatography. This protein bound efficiently to hyaluronate in vitro. Dog and human GHAP had identical isoelectric points and similar peptide maps but different molecular weights. Dog GHAP (70 kD) was larger than its human counterpart (60 kD). These findings imply that GHAP exists in association with hyaluronate in CNS white matter. Immunoelectron microscopy revealed that GHAP fills the space between myelin sheaths in dog spinal cord white matter. One is led to conclude therefore that an hyaluronate based extracellular matrix exists in CNS white matter.
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PMID:Extracellular matrix of central nervous system white matter: demonstration of an hyaluronate-protein complex. 171 74

In the rat, intracerebral injection of bacterial hyaluronidase resulted in the almost complete disappearance of hyaluronic acid (HA) and glial hyaluronate-binding protein (GHAP) from cerebral hemispheres, brain stem, and cerebellum (but not from optic nerves and chiasm) starting 2-3 hr after the injection. HA and GHAP reappeared throughout the brain in characteristic patches 2-3 days after the injection. The patches gradually became confluent and after 12 days the brain appeared virtually normal. In normal rat optic nerve, staining for HA and GHAP ceased abruptly in the region of the lamina cribrosa. The retina was completely negative. HA and GHAP disappeared from hyaluronidase-injected optic nerve, chiasm, and contralateral optic nerve. In hyaluronidase-injected crushed optic nerves, regenerated axons were able to grow for short distances (about 500 microns) into the distal stump undergoing Wallerian degeneration. No such growth was observed in saline-injected controls.
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PMID:Effect of hyaluronidase on brain extracellular matrix in vivo and optic nerve regeneration. 750 41

Hyaluronic acid (HA) plays the main structural role in the formation of brain extracellular matrix (ECM). The extracellular space appears empty by electron microscopy because HA is readily dissolved during the preparation of tissues for ultrastructural studies. The HA-binding proteins so far identified in brain ECM are versican, aggrecan and the glial HA-binding protein. Versican is a large fibroblast proteoglycan preferentially expressed in embryonic cartilage at the time of mesenchymal condensation. Glial HA-binding protein (GHAP) is probably a proteolytic product of versican corresponding to its HA-binding amino-terminal domain. It is mainly a white-matter protein, suggesting that the proteinase responsible for its cleavage from versican is normally activated in this location. Versican is found in both white matter and gray matter, where it forms pericellular coats around large neurons. Aggrecan, the aggregating proteoglycan of mature cartilage, co-localizes with versican in this location. In white matter, the localization of GHAP and versican is identical to that of the glial fibrillary acid protein, suggesting that both proteins are produced by astrocytes. An important difference between GHAP and versican is that GHAP but not versican is released from the tissues by hyaluronidase digestion, which suggests that versican is anchored to the cell membranes lining the extracellular space. GHAP was localized at the ultrastructural level in the granule cell layer of rat cerebellum, the only region of gray matter that is positive for GHAP in this species. Rats were perfused with aqueous fixatives containing cetylpyridinium chloride or tannic acid to prevent the solubilization of HA. GHAP is found throughout the extracellular space, the synaptic clefts being a notable exception. GHAP appears late in development, and the same is true for versican, the characteristic perineuronal coats first becoming apparent in the third postnatal week. It is suggested that a marked change occurs in the structure of brain ECM when HA-binding proteins first appear, and that the change is similar to that observed in prechondrogenic mesenchyme, i.e., reduction of the extracellular space and cell aggregation.
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PMID:Hyaluronic acid and hyaluronic acid-binding proteins in brain extracellular matrix. 750 95

Unlike many tissues, the adult central nervous system extracellular matrix (ECM) has few known components. Previously, we characterized a large chondroitin sulfate proteoglycan, pgT1, from adult rat brain which has the properties of a general brain ECM component and is immunologically distinct from aggrecan and versican (Iwata, M., and Carlson, S.S. (1993) J. Neurosci. 13, 195-207). In this study we demonstrate that pgT1 binds hyaluronan with relatively high affinity. The pgT1 preparation isolated from rat brain aggregates in non-denaturing conditions. This aggregation is abolished by incubation of pgT1 with Streptomyces hyaluronidase. Examination of these aggregates by electron microscope reveals a structure in which an average of 18 subunits arise laterally from opposite sides of an elongated 350-nm filament. These pgT1 aggregates resemble the proteoglycan aggregates in cartilage which are composed of aggrecan and hyaluronan. Using affinity coelectrophoresis, we measure a dissociation constant (Kd) of 0.9 +/- 0.2 nM for the interaction of pgT1 and hyaluronan. These new findings, combined with the general distribution of pgT1 in brain, suggest that pgT1/hyaluronan aggregates are an extended general structure of the brain extracellular matrix network.
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PMID:A brain extracellular matrix proteoglycan forms aggregates with hyaluronan. 832 82

In the preovulatory follicle, the oocyte is surrounded by approximately 1000 closely associated cumulus cells forming the compact form of the cumulus cell-oocyte complex (COC). In response to the gonadotropin surge, the COC in a follicle destined for ovulation undergoes expansion when the cumulus cells synthesize and organize an extensive extracellular matrix enriched in hyaluronan. Successful expansion of the COC appears to be essential for ovulation and ultimately for fertilization. We studied this process in vitro by isolating compact COCs from preovulatory mouse follicles and incubating them under conditions which promote COC expansion by retention of newly synthesized hyaluronan (HA in the extracellular matrix around the cells. [3H]-Leucine and [35S]sulfate were used as precursors to label macromolecules synthesized by the cells that may be necessary for organizing the HA in this matrix. After labeling, expanded COCs were washed to remove medium and any labeled molecules that were not associated with the matrix. Macromolecules selectively associated with the matrix were then solubilized by digesting the expanded COCs briefly with Streptomyces hyaluronidase, an enzyme that specifically cleaves HA. Cells were removed by centrifugation, and the digest supernate was analyzed by molecular sieve chromatography and SDS-PAGE. A dermatan sulfate proteoglycan of large hydrodynamic size ( > 1 million Da) and a approximately 46-kDa protein were the predominant labeled species identified. The proteoglycan has properties similar to proteoglycans such as aggrecan and versican which interact specifically with HA. The approximately 46-kDa protein has the same molecular size as the link protein which interacts with HA and HA-binding proteoglycans to form stable ternary complexes in a variety of extracellular matrices. We propose that the dermatan sulfate proteoglycan and the approximately 46-kDa protein synthesized by the cumulus cells form similar ternary complexes that are necessary for retaining HA in the COC matrix and hence are required for successful COC expansion.
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PMID:Proteoglycans and proteins in the extracellular matrix of mouse cumulus cell-oocyte complexes. 856 97

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

Chondroitin sulfate proteoglycan (CS-PG) expression is increased in response to CNS injury and limits the capacity for axonal regeneration. Previously we have shown that neurocan is one of the CS-PGs that is upregulated (Asher et al., 2000). Here we show that another member of the aggrecan family, versican, is also upregulated in response to CNS injury. Labeling of frozen sections 7 d after a unilateral knife lesion to the cerebral cortex revealed a clear increase in versican immunoreactivity around the lesion. Western blot analysis of extracts prepared from injured and uninjured tissue also revealed considerably more versican in the injured tissue extract. In vitro studies revealed versican to be a product of oligodendrocyte lineage cells (OLCs). Labeling was seen between the late A2B5-positive stage and the O1-positive pre-oligodendrocyte stage. Neither immature, bipolar A2B5-positive cells, nor differentiated, myelin-forming oligodendrocytes were labeled. The amount of versican in conditioned medium increased as these cells differentiated. Versican and tenascin-R colocalized in OLCs, and coimmunoprecipitation indicated that the two exist as a complex in oligodendrocyte-conditioned medium. Treatment of pre-oligodendrocytes with hyaluronidase led to the release of versican, indicating that its retention at the cell surface is dependent on hyaluronate (HA). In rat brain, approximately half of the versican is bound to hyaluronate. We also provide evidence of a role for CS-PGs in the axon growth-inhibitory properties of oligodendrocytes. Because large numbers of OLCs are recruited to CNS lesions, these results suggest that OLC-derived versican contributes to the inhospitable environment of the injured CNS.
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PMID:Versican is upregulated in CNS injury and is a product of oligodendrocyte lineage cells. 1189 62

Many chondroitin sulfate proteoglycans (CSPGs) have been shown to influence CNS axon growth in vitro and in vivo. These interactions can be mediated through the core protein or through the chondroitin sulfate (CS) glycosaminoglycan (GAG) side chains. We have shown previously that degrading CS GAG side chains using chondroitinase ABC enhances dopaminergic nigrostriatal axon regeneration in vivo. We test the hypothesis that interfering with complete CSPGs also limit axon growth in vivo. Neurocan, versican, aggrecan, and brevican CSPGs may be anchored within extracellular matrix through binding to hyaluronan glycosaminoglycan. We examine whether degradation of hyaluronan using hyaluronidase might release these inhibitory CSPGs from the extracellular matrix and thereby enhance regeneration of cut nigrostriatal axons. Anesthetized adult rats were given knife cut lesions of the right hemisphere nigrostriatal tract and cannulae were secured transcranially thereby allowing repeated perilesional infusion of saline or saline containing hyaluronidase once daily for 10 days post-axotomy. Eleven days post-transection brains from animals under terminal anesthesia were recovered for histological evaluation. Effective delivery of substance was inferred from the observed reduction in perilesional immunoreactivity for neurocan and versican after treatment with hyaluronidase (relative to saline). Immunolabeling using antibodies against tyrosine hydroxylase was used to examine the response of cut dopaminergic nigral neurons. After transection and treatment with saline, dopaminergic nigral neurons sprouted in a region lacking astrocytes, neurocan and versican. Axons did not regenerate into the lesion surround that contained astrocytes and abundant neurocan and versican. After transection and treatment with hyaluronidase, there was a significant increase in the number of cut dopaminergic nigral axons growing up to 800 microm anterior to the site of transection. However, cut dopaminergic nigral axons still did not regenerate into the lesion surround that contained reduced (albeit residual) neurocan and versican immunoreactivity. Thus, partial degradation of hyaluronan and chondroitin sulfate and depletion of hyaluronan-binding CSPGs enhances local sprouting of cut CNS axons, but long-distance regeneration fails in regions containing residual hyaluronan-binding CSPGs. Hyaluronan, chondroitin sulfate and hyaluronan-binding CSPGs therefore likely contribute toward the failure of spontaneous axon regeneration in the injured adult mammalian brain and spinal cord.
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PMID:Limited growth of severed CNS axons after treatment of adult rat brain with hyaluronidase. 1247 11


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