Analysis of glycosaminoglycan-degrading enzymes by substrate gel electrophoresis (zymography)

Insights into the source, mechanism and biotechnological applications of hyaluronidases

It has long been found that hyaluronidases exist in a variety of organisms, playing their roles in various biological processes including infection, envenomation and metabolic regulation through degrading hyaluronan. However, exploiting them as a bioresource for specific applications had not been extensively studied until the latest decades. In recent years, new application scenarios have been developed, which extended the field of application, and emphasized the research value of hyaluronidase. This critical review comprehensively summarizes existing studies on hyaluronidase from different source, particularly in their structures, action patterns, and biological functions in human and mammals. Furthermore, we give in-depth insight into the resource mining and protein engineering process of hyaluronidase, as well as strategies for their high-level production, indicating that mixed strategies should be adopted to obtain well-performing hyaluronidase with efficiency. In addition, advances in application of hyaluronidase were summarized and discussed. Finally, prospects for future researches are proposed, highlighting the importance of further investigation into the characteristics of hyaluronidases, and the necessity of investigating their products for the development of their application value.

An Inexpensive Staining Alternative for Gelatin Zymography Gels

Zymography is a widely used electrophoretic method to determine proteolytic activities in samples from various sources. The method is based on copolymerizing a suitable protein substrate within a sodium dodecyl sulfate-polyacrylamide gel. Following electrophoretic separation of the protease containing samples and a suitable incubation period, degradation of the substrate can be visualized through staining with Coomassie blue. Sites of proteolysis become visible as white bands on a dark blue background. However, this staining protocol requires considerable amounts of ethanol and acetic acid to remove unbound dye molecules. In this report, we describe a new staining protocol using Ponceau S which offers substantial advantages in terms of assay usability and cost reduction, especially when performing large quantities of zymograms or in resource-limited settings. Fast and reproducible staining of zymograms with our protocol is demonstrated, and reliable quantitation of proteolytic activity in comparison to the standard Coomassie staining procedure is shown.

Proteoglycan-substrate gel zymography for the detection of chondroitin sulfate-degrading enzymes

Chondroitin sulfate (CS), a linear polysaccharide, is a major component of the cartilage matrix. Although CS plays various roles in several biological and pathological processes, most details regarding its metabolism are still poorly understood. Some CS-degrading enzymes have been identified in mammals, but their expression patterns and localizations remain unclear. Here we present a simple zymography procedure to detect CS-degrading enzymes using salmon nasal cartilage proteoglycans as substrates. This method should be useful to explore CS-degrading enzymes.

Biochemical and structural characterization of a protein complex containing a hyaluronidase and a CRISP-like protein isolated from the venom of the spider Acanthoscurria natalensis

Spider venoms are composed of a complex mixture of bioactive molecules. The structural and functional characterization of these molecules in the venom of the Brazilian spider Acanthoscurria natalensis, has been little explored. The venom was fractionated using reversed-phase liquid chromatography. The fraction with hyaluronidase activity was named AnHyal. The partial sequencing of AnHyal revealed the presence of a CRISP-like protein, in addition to hyaluronidase, comprising 67% coverage for hyaluronidase from Brachypelma vagans and 82% for CRISP-like protein from Grammostola rosea. 1D BN-PAGE zymogram assays of AnHyal confirmed the presence of enzymatically active 53 kDa monomer and 124 and 178 kDa oligomers. The decomposition of the complexes by 2D BN/SDS-PAGE zymogram assays showed two subunits, 53 (AnHyalH) and 44 kDa (AnHyalC), with sequence similarity to hyaluronidase and CRISP proteins, respectively. The secondary structure of AnHyal is composed by 36% of α-helix. AnHyal presented maximum activity at pH between 4.0 and 6.0 and 30 and 60 °C, showed specificity to hyaluronic acid substrate and presented a K_M of 617.9 μg/mL. Our results showed that hyaluronidase and CRISP proteins can form a complex and the CRISP protein may contribute to the enzymatic activity of AnHyalH.

Biochemical and biological characterization of Bothriechis schlegelii snake venoms from Colombia and Costa Rica

Snakebites inflicted by the arboreal viperid snake Bothriechis schlegelii in humans are characterized by pain, edema, and ecchymosis at the site of the bite, rarely with blisters, local necrosis, or defibrination. Herein, a comparative study of Bothriechis schlegelii snake venoms from Colombia (BsCo) and Costa Rica (BsCR) was carried out in order to compare their main activities and to verify the efficacy of Bothrops antivenom produced in Brazil to neutralize them. Biochemical (SDS-PAGE and zymography) and biological parameters (edematogenic, lethal, hemorrhagic, nociceptive, and phospholipase A₂ activities) induced by BsCo and BsCR snake venoms were evaluated. The presence of antibodies in Bothrops antivenom that recognize BsCo and BsCR snake venoms by enzyme-linked immunosorbent assay and Western blotting, as well as the ability of this antivenom to neutralize the toxic activities were also verified. SDS-PAGE showed differences between venoms. Distinctive caseinolytic and hyaluronidase patterns were detected by zymography. BsCo and BsCR showed similar phospholipase A₂ activity. Strong cross-reactivity between BsCo and BsCR was detected using Bothrops antivenom with many components located between 150 and 35 kDa. BsCR was more edematogenic and almost fourfold more hemorrhagic than BsCo, and both venoms induced nociception. BsCR (LD₅₀ 5.60 mg/kg) was more lethal to mice than BsCo (LD₅₀ 9.24 mg/kg). Bothrops antivenom was effective in the neutralization of lethal and hemorrhagic activities of BsCo and BsCR and was partially effective in the neutralization of edematogenic and nociceptive activities. In conclusion, geographic distribution influences the composition and activities of Bothriechis schlegelii venoms. Bothrops antivenom cross-reacted with these venoms and was partially effective in neutralizing some toxic activities of BsCo and BsCR.

Decreased hyaluronan concentration during primary rhegmatogenous retinal detachment

PURPOSE

To evaluate the concentration and molecular weight of hyaluronan (HA) polysaccharides as well as hyaluronidase activity in patients with rhegmatogenous retinal detachment (RRD).

METHODS

Twenty vitreous samples from 20 patients with RRD and 19 samples from 19 patients with idiopathic epiretinal membrane, macular hole, or vitreomacular traction syndrome were collected during surgical management with pars plana vitrectomy. The molecular weight of various HA fragments was assessed using agarose gel electrophoresis. Enzyme-linked immunosorbent assay was employed for the measurement of HA (in μg/mL). Hyaluronidase activity was evaluated using substrate (HA) sodium dodecyl sulfate polyacrylamide gel electrophoresis.

RESULTS

Agarose gel electrophoresis showed that the vitreous of the control group contained HA of high molecular mass, in contrast with the patient group. Mean HA concentration in the patient group was 50.96 μg/mL and differed significantly from that of the control group, which was 271.81 μg/mL (p<0.0005). Hyaluronidase activity was significantly higher in the vitreous of patients with RRD (p = 0.037).

CONCLUSIONS

The vitreous of patients with RRD is characterized by decreased HA concentration compared to controls of the same age and sex and shows higher hyaluronidase catalytic activity. Hyaluronan degradation could be associated with specific vitreous alterations that potentially contribute to retinal break formation and consequently detachment.

Jellyfish Bioactive Compounds: Methods for Wet-Lab Work

The study of bioactive compounds from marine animals has provided, over time, an endless source of interesting molecules. Jellyfish are commonly targets of study due to their toxic proteins. However, there is a gap in reviewing successful wet-lab methods employed in these animals, which compromises the fast progress in the detection of related biomolecules. Here, we provide a compilation of the most effective wet-lab methodologies for jellyfish venom extraction prior to proteomic analysis-separation, identification and toxicity assays. This includes SDS-PAGE, 2DE, gel chromatography, HPLC, DEAE, LC-MS, MALDI, Western blot, hemolytic assay, antimicrobial assay and protease activity assay. For a more comprehensive approach, jellyfish toxicity studies should further consider transcriptome sequencing. We reviewed such methodologies and other genomic techniques used prior to the deep sequencing of transcripts, including RNA extraction, construction of cDNA libraries and RACE. Overall, we provide an overview of the most promising methods and their successful implementation for optimizing time and effort when studying jellyfish.

Increase of glycosaminoglycans and metalloproteinases 2 and 9 in liver extracellular matrix on early stages of extrahepatic cholestasis

CONTEXT

Cholestasis produces hepatocellular injury, leukocyte infiltration, ductular cells proliferation and fibrosis of liver parenchyma by extracellular matrix replacement.

OBJECTIVE

Analyze bile duct ligation effect upon glycosaminoglycans content and matrix metalloproteinase (MMPs) activities.

METHODS

Animals (6-8 weeks; n = 40) were euthanized 2, 7 or 14 days after bile duct ligation or Sham-surgery. Disease evolution was analyzed by body and liver weight, seric direct bilirubin, globulins, gamma glutamyl transpeptidase (GGT), alkaline phosphatase (Alk-P), alanine and aspartate aminotransferases (ALT and AST), tissue myeloperoxidase and MMP-9, pro MMP-2 and MMP-2 activities, histopathology and glycosaminoglycans content.

RESULTS

Cholestasis caused cellular damage with elevation of globulins, GGT, Alk-P, ALT, AST. There was neutrophil infiltration observed by the increasing of myeloperoxidase activity on 7 (P = 0.0064) and 14 (P = 0.0002) groups which leads to the magnification of tissue injuries. Bile duct ligation increased pro-MMP-2 (P = 0.0667), MMP-2 (P = 0.0003) and MMP-9 (P<0.0001) activities on 14 days indicating matrix remodeling and establishment of inflammatory process. Bile duct ligation animals showed an increasing on dermatan sulfate and/or heparan sulfate content reflecting extracellular matrix production and growing mitosis due to parenchyma depletion.

CONCLUSIONS

Cholestasis led to many changes on rats' liver parenchyma, as so as on its extracellular matrix, with major alterations on MMPs activities and glycosaminoglycans content.

Positive correlation between disease activity index and matrix metalloproteinases activity in a rat model of colitis

CONTEXT

Inflammatory bowel disease, including ulcerative colitis and Crohn's disease, comprising a broad spectrum of diseases those have in common chronic inflammation of the gastrointestinal tract, histological alterations and an increased activity levels of certain enzymes, such as, metalloproteinases.

OBJECTIVES

Evaluate a possible correlation of disease activity index with the severity of colonic mucosal damage and increased activity of metalloproteinases in a model of ulcerative colitis induced by dextran sulfate sodium.

METHODS

Colitis was induced by oral administration of 5% dextran sulfate sodium for seven days in this group (n=10), whereas control group (n=16) received water. Effects were analyzed daily by disease activity index. In the seventh day, animals were euthanized and hematological measurements, histological changes (hematoxylin and eosin and Alcian Blue staining), myeloperoxidase and metalloproteinase activities (MMP-2 and MMP-9) were determined.

RESULTS

Dextran sulfate sodium group showed elevated disease activity index and reduced hematological parameters. Induction of colitis caused tissue injury with loss of mucin and increased myeloperoxidase (P<0.001) and MMP-9 activities (45 fold) compared to the control group.

CONCLUSIONS

In this study, we observed a disease activity index correlation with the degree of histopathological changes after induction of colitis, and this result may be related mainly to the increased activity of MMP-9 and mieloperoxidase.

Hyaluronan (HA) interacting proteins RHAMM and hyaluronidase impact prostate cancer cell behavior and invadopodia formation in 3D HA-based hydrogels

To study the individual functions of hyaluronan interacting proteins in prostate cancer (PCa) motility through connective tissues, we developed a novel three-dimensional (3D) hyaluronic acid (HA) hydrogel assay that provides a flexible, quantifiable, and physiologically relevant alternative to current methods. Invasion in this system reflects the prevalence of HA in connective tissues and its role in the promotion of cancer cell motility and tissue invasion, making the system ideal to study invasion through bone marrow or other HA-rich connective tissues. The bio-compatible cross-linking process we used allows for direct encapsulation of cancer cells within the gel where they adopt a distinct, cluster-like morphology. Metastatic PCa cells in these hydrogels develop fingerlike structures, “invadopodia”, consistent with their invasive properties. The number of invadopodia, as well as cluster size, shape, and convergence, can provide a quantifiable measure of invasive potential. Among candidate hyaluronan interacting proteins that could be responsible for the behavior we observed, we found that culture in the HA hydrogel triggers invasive PCa cells to differentially express and localize receptor for hyaluronan mediated motility (RHAMM)/CD168 which, in the absence of CD44, appears to contribute to PCa motility and invasion by interacting with the HA hydrogel components. PCa cell invasion through the HA hydrogel also was found to depend on the activity of hyaluronidases. Studies shown here reveal that while hyaluronidase activity is necessary for invadopodia and inter-connecting cluster formation, activity alone is not sufficient for acquisition of invasiveness to occur. We therefore suggest that development of invasive behavior in 3D HA-based systems requires development of additional cellular features, such as activation of motility associated pathways that regulate formation of invadopodia. Thus, we report development of a 3D system amenable to dissection of biological processes associated with cancer cell motility through HA-rich connective tissues.

Scyphozoan jellyfish venom metalloproteinases and their role in the cytotoxicity

The present study, for the first time, comparatively investigated the enzymatic activities (proteases and hyaluronidases) in the venoms of four Scyphozoan jellyfish species, including Nemopilema nomurai, Rhopilema esculenta, Cyanea nozakii, and Aurelia aurita. For this, various zymographic analyses were performed using assay specific substrates. Interestingly, all the four jellyfish venoms showed gelatinolytic, caseinolytic, and fibrinolytic activities, each of which contains a multitude of enzyme components with molecular weights between 17 and 130 kDa. These four jellyfish venoms demonstrated a huge variation in their proteolytic activities in quantitative and qualitative manner depending on the species. Most of these enzymatic activities were disappeared by the treatment of 1,10-phenanthroline, suggesting they might be belonged to metalloproteinases. Toxicological significance of these venom proteases was examined by comparing their proteolytic activity and the cytotoxicity in NIH 3T3 cells. The relative cytotoxic potency was C. nozakii > N. nomurai > A. aurita > R. esculenta. The cytotoxicity of jellyfish venom shows a positive correlation with its overall proteolytic activity. The metalloproteinases appear to play an important role in the induction of jellyfish venom toxicities. In conclusion, the present report proposes a novel finding of Scyphozoan jellyfish venom metalloproteinases and their potential role in the cytotoxicity.

Endothelial surface layer degradation by chronic hyaluronidase infusion induces proteinuria in apolipoprotein E-deficient mice

Objective

Functional studies show that disruption of endothelial surface layer (ESL) is accompanied by enhanced sensitivity of the vasculature towards atherogenic stimuli. However, relevance of ESL disruption as causal mechanism for vascular dysfunction remains to be demonstrated. We examined if loss of ESL through enzymatic degradation would affect vascular barrier properties in an atherogenic model.

Methods

Eight week old male apolipoprotein E deficient mice on Western-type diet for 10 weeks received continuous active or heat-inactivated hyaluronidase (10 U/hr, i.v.) through an osmotic minipump during 4 weeks. Blood chemistry and anatomic changes in both macrovasculature and kidneys were examined.

Results

Infusion with active hyaluronidase resulted in decreased ESL (0.32±0.22 mL) and plasma volume (1.03±0.18 mL) compared to inactivated hyaluronidase (0.52±0.29 mL and 1.28±0.08 mL, p<0.05 respectively).Active hyaluronidase increased proteinuria compared to inactive hyaluronidase (0.27±0.02 vs. 0.15±0.01 µg/µg protein/creatinin, p<0.05) without changes in glomerular morphology or development of tubulo-interstitial inflammation. Atherosclerotic lesions in the aortic branches showed increased matrix production (collagen, 32±5 vs. 18±3%; glycosaminoglycans, 11±5 vs. 0.1±0.01%, active vs. inactive hyaluronidase, p<0.05).

Conclusion

ESL degradation in apoE deficient mice contributes to reduced increased urinary protein excretion without significant changes in renal morphology. Second, the induction of compositional changes in atherogenic plaques by hyaluronidase point towards increased plaque vulnerability. These findings support further efforts to evaluate whether ESL restoration is a valuable target to prevent (micro) vascular disease progression.

Production of human hyaluronidase in a plant-derived protein expression system: plant-based transient production of active human hyaluronidase

Four types of human hyaluronidases (rHuHyal-1, -2, -3 and -4) were transiently expressed and purified from Nicotiana benthamiana, and their biochemical characteristics were analyzed. The recombinant HuHyals were expressed via agrobacteria-mediated infiltration and generated and expressed in terms of micrograms per 5 leaves of N. benthamiana. Expressed recombinant HuHyals were purified using a His(6) tagging system and Ni column chromatography, respectively, at pH 8.0, after which the purified rHuHyals were concentrated for additional biochemical analyses. The four types of rHuHyals were allowed to react with hyaluronic acids and chondroitin sulfates. The biochemical properties of rHuHyal-1 fit those of the commercially available Hyal, PH-20, which was extracted from animal testes under acidic conditions (pH 3.5). However, rHuHyal-1 evidenced activity levels 2 to 6-fold greater than the three other rHuHyals (rHuHyal-2, -3 and -4) at pH 3.5. However, only rHuHyal-4 exhibited chondroitinase activity with both 6-S-chondroitin sulfate (chondroitin sulfate C) and 4-S-chondroitin sulfate (chondroitin sulfate A) as standard substrates. The results of zymography demonstrated that recombinant HuHyal 1 was modified by glycosylation, but Escherichia coli Hyal was not. This result demonstrated that plant-based rHuHyal was functionally active and evidenced biochemical characteristics and post-translational protein modifications similar to those of animal testis-derived Hyal.

Identification, characterization, and molecular cloning of a novel hyaluronidase, a member of glycosyl hydrolase family 16, from Penicillium spp

Hyaluronidase (HAase) activity was detected in the culture supernatants of Penicillium purpurogenum and Penicillium funiculosum. The HAase from Penicillium spp. (HAase-P) was a hyaluronate 4-glycanohydrolase, which catalyzed the endolytic hydrolysis of the β-1,4 glycosidic linkage, as do vertebrate HAases. The gene encoding HAase-P was cloned and expressed in Escherichia coli. According to homology analyses of the deduced amino acid sequences, HAase-P is not classified into any of the known HAase groups, but belongs to glycoside hydrolase family 16, which includes endo-β-1,3(4)-glucanase. Regarding the substrate specificities, no chondroitinase and glucanase activities were detected. Judging from homology analyses and enzymatic properties, HAase-P seems to be a new type of HAase.

Effect of fetal size on fetal placental hyaluronan and hyaluronoglucosaminidases throughout gestation in the pig

The trophoblast-endometrial epithelial cell bilayer of porcine placenta undergoes microscopic folding during gestation, and the folded bilayer is embedded in fetal placental stroma. We hypothesized that hyaluronan was a component of fetal placental stroma, and that hyaluronoglucosaminidases played a role in bilayer folding. Gilts were unilaterally hysterectomized-ovariectomized (UHO) at 160 days of age, mated at estrus and killed on days 25, 45, 65, 85 or 105 of gestation. Fetal placental tissues were collected to evaluate hyaluronan and hyaluronoglucosaminidase content. Fetal placental hyaluronan concentration increased (P<0.01) between day 25 and 45 of gestation, remained high throughout gestation, and was greater (P<0.05) in the fetal placenta of the smallest compared to the largest fetuses on day 105 of gestation. Hyaluronan was localized to fetal placental stroma. Three cDNAs for hyaluronoglucosaminidase 1 (two 1379 and one 1552bp) and one cDNA (1421bp) for hyaluronoglucosaminidase 2 were cloned from day-85 fetal placental RNA. Gene expression analysis indicated that the 1379bp form of hyaluronoglucosaminidase 1 mRNA did not differ, the 1552bp form increased, and the 1421bp form of hyaluronoglucosaminidase 2 decreased during pregnancy. Amount of all three mRNAs was greater (P<0.05) in fetal placenta of the smallest compared to the largest fetuses. Zymography indicated 70 and 55kd protein isoforms of hyaluronoglucosaminidase in fetal placental tissue. Both forms increased with advancing gestation and were greater in fetal placenta of the smallest compared to the largest fetuses (P<0.05). These results are consistent with a role for hyaluronan and hyaluronoglucosaminidases in the development of the microscopic folds of the pig placenta during gestation.

Mammalian hyaluronidase induces ovarian granulosa cell apoptosis and is involved in follicular atresia

During ovarian folliculogenesis, the vast majority of follicles will undergo atresia by apoptosis, allowing a few dominant follicles to mature. Mammalian hyaluronidases comprise a family of six to seven enzymes sharing the same catalytic domain responsible for hyaluronan hydrolysis. Interestingly, some of these enzymes have been shown to induce apoptosis. In the ovary, expression of three hyaluronidases (Hyal-1, Hyal-2, and Hyal-3) has been documented. However, their precise cellular localization and role in ovarian regulation have not yet been defined. We herein investigated the possible involvement of these enzymes in ovarian atresia. First, we established a mouse model for ovarian atresia (gonadotropin withdrawal by anti-equine chorionic gonadotropin treatment) and showed that the mRNA levels of Hyal-1, Hyal-2, and Hyal-3 were significantly increased in apoptotic granulosa cells as well as in atretic follicles. Second, using ovaries of normally cycling mice, we demonstrated the correlation of Hyal-1 mRNA and protein expression with cleavage of caspase-3. In addition, we showed that expression of all three hyaluronidases induced apoptosis in transfected granulosa cells. Significantly, the induction of apoptosis by hyaluronidases was independent of catalytic activity, because enzymatically inactive Hyal-1 mutant (D157A/E159A) was as efficient as the wild-type enzyme in apoptosis induction. The activation of the extrinsic apoptotic signaling pathway was involved in this induction, because increased levels of cleaved caspase-8, caspase-3, and poly-ADP-ribose polymerase (PARP) were observed upon hyaluronidase ectopic expression. Our present findings provide a better understanding of the role of hyaluronidases in ovarian functions, showing for the first time their involvement in follicular atresia.

A mouse model of human mucopolysaccharidosis IX exhibits osteoarthritis

Hyaluronidases are endoglycosidases that hydrolyze hyaluronan (HA), an abundant component of the extracellular matrix of vertebrate connective tissues. Six human hyaluronidase-related genes have been identified to date. Mutations in one of these genes cause a deficiency of hyaluronidase 1 (HYAL1) resulting in a lysosomal storage disorder, mucopolysaccharidosis (MPS) IX. We have characterized a mouse model of MPS IX and compared its phenotype with the human disease. The targeted Hyal1 allele in this model had a neomycin resistance cassette in exon 2 that replaced 753 bp of the coding region containing the predicted enzyme active site. As a result, Hyal1(-/-) animals had no detectable wild-type Hyal1 transcript, protein or serum activity. Hyal1 null animals were viable, fertile and showed no gross abnormalities at 1 year and 8 months of age. Histological studies of the knee joint showed a loss of proteoglycans occurring as early as 3 months that progressed with age. An increased number of chondrocytes displaying intense pericellular and/or cytoplasmic HA staining were detected in the epiphyseal and articular cartilage of null mice, demonstrating an accumulation of HA. Elevations of HA were not detected in the serum or non-skeletal tissues, indicating that osteoarthritis is the key disease feature in a Hyal1 deficiency. Hyal3 expression was elevated in Hyal1 null mice, suggesting that Hyal3 may compensate in HA degradation in non-skeletal tissues. Overall, the murine MPS IX model displays the key features of the human disease.

Cisplatin‐incorporated hyaluronic acid nanoparticles based on ion‐complex formation

The aim of this study is to prepare cisplatin-incorporated nanoparticles based on ion complex formation between hyaluronic acid (HA) and cisplatin for antitumor drug delivery. To prepare nanoparticles using HA, bulk HA was degraded by hyaluronidases (HAses). Cisplatin-incorporated HA nanoparticles were prepared by mixing cisplatin with an aqueous solution of HA and then the nanoparticle solution was dialyzed to remove trace elements. Since glioma tumor cell lines are able to secrete HAse, extracts from U343MG and U87MG cell lines were used to test the release of cisplatin from the nanoparticles. The morphological observation of the cisplatin-incorporated nanoparticles showed that they had spherical shapes with a particle size around 100-200 nm. The loading efficiency of cisplatin in the nanoparticles was about 67-81% (w/w) and cisplatin was continuously released from the nanoparticles for 4 days. Especially, the release rate of cisplatin from the nanoparticles increased when HAse was added to the release medium. In the results of the HA zymography, the U343MG cell line secreted HAse, while the U87MG cell line did not. When the extracts from U343MG were added to the release medium, the release rate of cisplatin was slightly increased, while the extracts from U87MG did not significantly affect the release rate of cisplatin. In conclusion, cisplatin-incorporated nanoparticles have sufficiently small particle sizes to use as a drug targeting system. The release of cisplatin from the nanoparticles was responsive to the secretion of HAse. These nanoparticles are suitable vehicles for an antitumor drug targeting system.

Extracellular superoxide dismutase inhibits inflammation by preventing oxidative fragmentation of hyaluronan

Extracellular superoxide dismutase (EC-SOD) is expressed at high levels in lungs. EC-SOD has a polycationic matrix-binding domain that binds to polyanionic constituents in the matrix. Previous studies indicate that EC-SOD protects the lung in both bleomycin- and asbestos-induced models of pulmonary fibrosis. Although the mechanism of EC-SOD protection is not fully understood, these studies indicate that EC-SOD plays an important role in regulating inflammatory responses to pulmonary injury. Hyaluronan is a polyanionic high molecular mass polysaccharide found in the extracellular matrix that is sensitive to oxidant-mediated fragmentation. Recent studies found that elevated levels of low molecular mass hyaluronan are associated with inflammatory conditions. We hypothesize that EC-SOD may inhibit pulmonary inflammation in part by preventing superoxide-mediated fragmentation of hyaluronan to low molecular mass fragments. We found that EC-SOD directly binds to hyaluronan and significantly inhibits oxidant-induced degradation of this glycosaminoglycan. In vitro human polymorphic neutrophil chemotaxis studies indicate that oxidative fragmentation of hyaluronan results in polymorphic neutrophil chemotaxis and that EC-SOD can completely prevent this response. Intratracheal injection of crocidolite asbestos in mice leads to pulmonary inflammation and injury that is enhanced in EC-SOD knock-out mice. Notably, hyaluronan levels are increased in the bronchoalveolar lavage fluid after asbestos-induced pulmonary injury, and this response is markedly enhanced in EC-SOD knock-out mice. These data indicate that inhibition of oxidative hyaluronan fragmentation probably represents one mechanism by which EC-SOD inhibits inflammation in response to lung injury.

Hyaluronan-CD44-ERK1/2 regulate human aortic smooth muscle cell motility during aging

The glycosaminoglycan hyaluronan (HA) modulates cell proliferation and migration, and it is involved in several human vascular pathologies including atherosclerosis and vascular restenosis. During intima layer thickening, HA increases dramatically in the neointima extracellular matrix. Aging is one of the major risk factors for the insurgence of vascular diseases, in which smooth muscle cells (SMCs) play a role by determining neointima formation through their migration and proliferation. Therefore, we established an in vitro aging model consisting of sequential passages of human aortic smooth muscle cells (AoSMCs). Comparing young and aged cells, we found that, during the aging process in vitro,HA synthesis significantly increases, as do HA synthetic enzymes (i.e. HAS2 and HAS3), the precursor synthetic enzyme (UDP-glucose dehydrogenase), and the HA receptor CD44. In aged cells, we also observed increased CD44 signaling that consisted of higher levels of phosphorylated MAP kinase ERK1/2. Further, aged AoSMCs migrated faster than young cells, and such migration could be modulated by HA, which alters the ERK1/2 phosphorylation. HA oligosaccharides of 6.8 kDa and an anti-CD44 blocking antibody prevented ERK1/2 phosphorylation and inhibited AoSMCs migration. These results indicate that, during aging, HA can modulate cell migration involving CD44-mediated signaling through ERK1/2. These data suggest that age-related HA accumulation could promote SMC migration and intima thickening during vascular neointima formation.

The effect of hyaluronic acid incorporation on fibroblast spreading and proliferation within PEG-diacrylate based semi-interpenetrating networks

The nanometer-scale mesh size of many synthetic crosslinked hydrogel networks restricts encapsulated cells to a rounded morphology that can inhibit cellular processes such as proliferation and migration that are essential for the early stages of remodeling and tissue formation. The objective of these studies was to investigate an approach for accelerating cellular remodeling based on the creation of semi-interpenetrating networks (IPNs) composed of hydrolytically degradable poly(ethylene glycol) (PEG) diacrylate macromers and native, enzymatically degradable extracellular matrix (ECM) components (collagen, gelatin and hyaluronic acid (HA)). Among the three ECM components investigated, addition of HA at concentrations of 0.12% w/v and greater supported fibroblast spreading throughout the three-dimensional network and significantly increased proliferation relative to control hydrogels without HA. Incorporation of HA resulted in relatively small changes in hydrogel physical/chemical properties such as swelling, degradation rate, and elastic modulus. Fibroblast spreading was eliminated by the addition of hyaluronidase inhibitors, demonstrating that cell-mediated enzymatic degradation of HA is a necessary mechanism responsible for the observed increases in fibroblast activity. By accelerating early cellular remodeling and growth, these semi-IPNs may be useful vehicles for cell transplantation in a variety of tissue engineering applications.

Comparative study on extracts from the tissue covering the stingers of freshwater (Potamotrygon falkneri) and marine (Dasyatis guttata) stingrays

Stingrays are elasmobranchs found along the seacoast and in some rivers of Brazil. Pain is the most conspicuous symptom observed in patients wounded by the bilaterally retroserrate stingers located in the tail, which are covered by glandular and integument tissues. In addition, cutaneous necrosis is commonly observed in injuries caused by freshwater stingrays. The aim of this work was to characterize and compare certain properties of tissue extracts obtained from the glandular tissues covering the stinger apparatus of Potamotrygon falkneri and Dasyatis guttata stingrays. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), tissue extracts have similar bands above 80 kDa, but most differences were observed below this molecular mass. Lethal, dermonecrotic and myotoxic activities were detected only in P. falkneri tissue extract. Edematogenic activity was similar and dose dependent in both tissue extracts. Nociceptive activity was verified in both tissue extracts, but P. falkneri presented a two-fold higher activity than D. guttata tissue extract. No direct hemolysis, phospholipase A2 and coagulant activities were observed in both tissue extracts. Antigenic cross-reactivity was noticed by ELISA and Western blotting, using antisera raised in rabbits. Species-specific sera reacted with several components of both tissue extracts, noticeably above 22kDa. Both tissue extracts presented gelatinolytic, caseinolytic and fibrinogenolytic activities, which were not caused by the action of metalloproteinases. Hyaluronidase activity was detected only in P. falkneri tissue extract. Our experimental observations suggest that P. falkneri tissue extract is more toxic than D. guttata tissue extract. These results may explain why injuries caused by freshwater stingrays are more severe in human accidents.

Enzymatic and immunochemical characterization of Bothrops insularis venom and its neutralization by polyspecific Bothrops antivenom

Herein we compared the biological activities of Bothrops insularis and Bothrops jararaca venoms as well as their neutralization by polyspecific Bothrops antivenom (PBA). On account of that, we investigated their antigenic cross-reactivity and the neutralization of lethal, myotoxic and defibrinating activities by polyspecific and species-specific antivenoms. Silver-stained SDS-PAGE gels evidenced many common bands particularly above 47 kDa between B. jararaca and B. insularis venoms. However, some protein bands between 46 and 28 kDa were observed exclusively in B. jararaca venom. Both venoms presented gelatinolytic, caseinolytic, fibrinogenolytic and phospholipase A(2) activities. No hyaluronidase activity was detected in both venoms by zymography. Polyspecific and species-specific antivenoms showed similar titers to B. jararaca and B. insularis venoms by ELISA, and recognized similar components by immunoblotting. The PBA was effective in neutralizing the lethal, myotoxic and defibrinating activities of both venoms as well as to abrogate microcirculatory disturbances induced by B. insularis venom. No statistically significant difference was observed for minimal hemorrhagic doses between both venoms. Antigenic cross-reactivity was evident between both venoms. Since toxic and enzymatic activities were similar, we speculate that B. insularis venoms can induce a local damage in humans comparable to that observed in other Bothrops venoms. Besides, the PBA was effective in neutralizing the toxic activities of B. insularis venom.

Apparent suppression of MMP-9 activity by GD1a as determined by gelatin zymography

Gelatin zymography is widely used to detect and evaluate matrix metalloproteinase-9 (MMP-9) activity. MMP-9 transcription was previously shown to be negatively regulated by ganglioside GD1a [D. Hu, Z. Man, T. Xuan, P. Wang, T. Takaku, S. Hyuga, X.S. Yao, T. Sato, S. Yamagata, T. Yamagata, Ganglioside GD1a regulation of matrix metalloproteinase-9 (MMP-9) expression in mouse FBJ cell Lines: GD1a suppression of MMP-9 expression stimulated by PI3K-Akt and p38 though not by the Erk signaling pathway, 2006, submitted for publication.]. Zymography of MMP-9 of FBJ-M5 cells preincubated with GD1a indicated a greater decrease in activity than expected from mRNA suppression. Incubation of conditioned medium containing MMP-9 with GD1a caused MMP-9 activity to decrease. Examination was thus made to confirm that MMP-9 activity is actually suppressed and/or MMP-9 protein undergoes degradation by GD1a. GD1a was found to have no effect on MMP-9 activity and Western blots indicated GD1a not to diminish MMP-9 during electrophoresis under reducing conditions. GD1a appeared to mediate the binding of a portion of MMP-9 with certain molecules, with consequently greater molecular mass on the gel, to cause decrease in the activity of MMP-9 at the site where it would normally appear. Caution should be used in doing gelatin zymography since molecules other than GD1a may similarly work, causing decrease in MMP-9 activity in zymography.

Expression and cellular localization of human hyaluronidase-2 in articular chondrocytes and cultured cell lines

OBJECTIVE

There is debate whether hyaluronan (HA) can be enzymatically degraded within the extracellular matrix of cartilage and other tissues or whether its catabolism occurs strictly within the lysosomal compartment of chondrocytes and other cell types. Previous studies have suggested that one of the lysosomal hyaluronidases (hyaluronidase-2) can be expressed as a functionally-active glycosyl phosphatidylinositol-linked protein at the surface of mammalian cells. If this form of hyaluronidase expression occurs in chondrocytes, this could represent a possible mechanism for extracellular HA cleavage. Thus, which hyaluronidases are expressed and where was the objective of this study.

METHODS

mRNA for hyaluronidases was quantified by reverse transcription-polymerase chain reaction (RT-PCR) and enzymatic activity by HA zymograms. Recombinant forms of hyaluronidase-2 were generated and expressed in model cell lines. A peptide-specific polyclonal antiserum was prepared to localize endogenous human hyaluronidase-2 in human articular chondrocytes.

RESULTS

Hyaluronidase-2 is the principal mRNA transcript expressed by primary human articular chondrocytes as well as various model cell lines. Recombinant hyaluronidase-2, containing N-terminal or C-terminal epitope tags, was strictly localized intracellularly and not released by treatment with a phosphatidylinositol-specific phospholipase. Endogenous hyaluronidase-2 expressed by human chondrocytes as well as HeLa cells could only be detected following detergent permeabilization of the plasma membranes.

CONCLUSIONS

These data suggest that on chondrocytes and other cell types examined, hyaluronidase-2 is not present or functional at the external plasma membrane. Thus, local turnover of HA is dependent on receptor-mediated endocytosis and delivery to low pH intracellular organelles for its complete degradation.

Characterization of promoter elements of the human HYAL-2 gene

The regulated catabolism of hyaluronan is critical to the function of many connective tissues. In cartilage, hyaluronan catabolism occurs locally by resident chondrocytes. To determine whether the expression of lysosomal hyaluronidases contributes to this regulation, the promoter elements associated with HYAL-2 gene expression were characterized. Human articular chondrocytes were found to express all three lysosomal hyaluronidases, HYAL-1, HYAL-2, and HYAL-3. HYAL-2 was the predominant gene product. Using 5' RACE (rapid amplification of cDNA ends) analysis, multiple transcription initiation sites were identified including a novel initiation site located within intron 1 of the gene expressed by human articular chondrocytes. The presence of multiple transcriptional initiation sites is a typical feature of TATA-less promoter regions, such as those of HYAL-2. Approximately 4000 bp of 5' flanking sequence of the HYAL-2 gene was characterized. Transient transfection of C-28/I2 cells with various 5' deletion constructs indicated that the region between +959 to +1158 (within intron 1) contains the basal promoter for HYAL-2 in chondrocytes. In addition, the region +224 to +958 contained a negative modulator that could control the basal expression level of HYAL-2. Treatment of human articular chondrocytes or C-28/I2 cells with various catabolic cytokines did not alter HYAL-2 mRNA expression, luciferase promoter expression, or hyaluronidase enzymatic activity. Thus, in chondrocytes HYAL-2 appears to be constitutively expressed and not inducibly regulated by catabolic agents. As such, it appears that the expression of lysosomal hyaluronidase participates little in the overall regulation of hyaluronan catabolism.

Enzymatic characterization, antigenic cross-reactivity and neutralization of dermonecrotic activity of five Loxosceles spider venoms of medical importance in the Americas

Loxosceles spiders have a wide distribution in the temperate and tropical regions of the world. Loxoscelism is characterized by necrotic skin ulceration at the bite site and, less commonly, a systemic illness that may be fatal. The purpose of this study was to characterize and compare aspects of the major medically important Loxosceles spider venoms in a standardized manner, particularly considering their neutralization by two Brazilian antivenoms. By SDS-PAGE (12% acrylamide), Loxosceles deserta, Loxosceles gaucho, Loxosceles intermedia, Loxosceles laeta and Loxosceles reclusa venoms had similar electrophoretic profiles, with the major protein bands of 32-35 kDa. All venoms exhibited gelatinolytic, caseinolytic and fibrinogenolytic activities in vitro with a large array of proteases, mainly between 18.1 and 31.8 kDa. Most of these enzymes were metalloproteases as this activity was abolished by 1,10-phenanthroline. Hyaluronidase activity was detected in a protein band of approximately 44 kDa in all venoms. Sphingomyelinase activity was demonstrated in all five venoms. Antigenic cross-reactivity, by Western blotting, was also observed among all venoms studied using commercial equine antivenoms produced in Brazil (Institute Butantan and CPPI). These antivenoms recognized mainly components between 25 and 40 kDa in all venoms with several minor components of >89 kDa. Strong cross-reactivity was also seen among all venoms through the ELISA technique (titre range: 64,000-512,000). All venoms (5 microg doses) induced a similar local reaction when injected intradermally into the flank of rabbits, demonstrating dermonecrosis, hemorrhage, vasoconstriction, edema, and erythema. However, no reaction was observed when each venom was pre-incubated (1 h, 37 degrees C) with Brazilian commercial sera prior to injection. The antivenoms also abolished the sphingomyelinase activity in vitro, suggesting the venoms of the major medically important Loxosceles spider species have generally similar toxic and enzymatic characteristics. Thus, as Brazilian commercial antivenoms are able to neutralize the dermonecrosis induced by Loxosceles venoms of diverse geographical origin, clinical studies should be undertaken on the potential for a single global Loxosceles antivenom.

Hyaluronan content of Wharton's jelly in healthy and Down syndrome fetuses

The mechanisms by which the excess genetic material of chromosome 21 results in the dysmorphologic features of Down syndrome (DS) are largely unknown. It has been found that the extracellular matrix of nuchal skin of DS fetuses exhibits an higher content of hyaluronan (HA) compared to that of euploid fetuses. Since HA plays a central role in many morphogenetic processes during embryogenesis, an alteration in its metabolism could be involved in the pathogenesis of several structural defects of DS. The extracellular matrix of umbilical cord (UC) is the mammalian tissue with one of the highest content of HA. Therefore we sought to explore the quantitative HA modifications during gestation, tissue distribution and HA metabolism in euploid and DS UCs. Euploid UCs (n=28) and UCs from DS fetuses (n=13) were obtained after termination of pregnancy, spontaneous abortion, or at delivery. Quantitative and molecular size analysis were performed using HPLC and FPLC. Tissue distribution was visualized by immunohistochemistry. Gene expression for HA synthases (HAS) and hyaluronidases (HYAL) were quantified by real-time PCR techniques and HYAL activity was detected by zymography. In euploid UC only HA of a molecular weight of 1700 kDA was present while in DS UC an additional lower weight HA molecule of 1100 kDA was found. Immunohistochemistry showed a larger amount of Wharton's jelly HA in DS UCs than in euploid UC. Real-time PCR analysis showed that HAS 2 and HYAL 2 were expressed at significant levels in all specimens. A higher expression of HAS 2 and a lower expression of HYAL 2 was found in the Wharton's jelly of DS fetuses compared to that of euploid fetuses at 14 weeks of gestation. On the contrary, at term HYAL 2 expression was higher in DS specimens than in those from euploid fetuses. Zymographic studies showed a similar behavior with a lower HYAL activity at early gestation and a higher HYAL activity at term gestation in DS UCs compared to euploid specimens. Therefore we can conclude that HA is more represented in DS UCs than in euploid UCs. A complex alteration of the HA metabolism characterized by an increased synthesis of lower weight HA molecules is a peculiarity of DS UCs.

Chondrocytes, synoviocytes and dermal fibroblasts all express PH-20, a hyaluronidase active at neutral pH

Hyaluronan (HA), an important component of connective tissues, is highly metabolically active, but the mechanisms involved in its catabolism are still largely unknown. We hypothesized that a protein similar to sperm PH-20, the only mammalian hyaluronidase known to be active at neutral pH, could be expressed in connective tissue cells. An mRNA transcript similar to that of PH-20 was found in chondrocytes, synoviocytes, and dermal fibroblasts, and its levels were enhanced upon stimulation with IL-1. In cell layers extracted with Triton X-100 – but not with octylglucoside – and in culture media, a polyclonal antipeptide anti-PH-20 antibody identified protein bands with a molecular weight similar to that of sperm PH-20 (60 to 65 kDa) and exhibiting a hyaluronidase activity at neutral pH. Further, upon stimulation with IL-1, the amounts of the neutral-active hyaluronidase increased in both cell layers and culture media. These findings contribute potential important new insights into the biology of connective tissues. It is likely that PH-20 facilitates cell-receptor-mediated uptake of HA, while overexpression or uncontrolled expression of the enzyme can cause great havoc to connective tissues: not only does HA fragmentation compromise the structural integrity of tissues, but also the HA fragments generated are highly angiogenic and are potent inducers of proinflammatory cytokines. On the other hand, the enzyme activity may account for the progressive depletion of HA seen in osteoarthritis cartilage, a depletion that is believed to play an important role in the apparent irreversibility of this disease process.

Optical zymography for specific detection of urokinase plasminogen activator activity in biological samples

Zymography techniques are routinely used to quantify proteolytic activity. In the current study, we describe an optical zymographic procedure that specifically detects urokinase-type plasminogen activator (uPA) activity in biological samples. The method employs a synthetic polymeric uPA fluorescent probe, which is copolymerized in sodium dodecyl sulfate (SDS)-polyacrylamide gel. Following electrophoresis and renaturation, enzymatic digestions of the substrate in 50 mM of Tris buffer at pH 7.4 generates fluorescence emission at 695 nm. The enzymatic activities can be analyzed directly by conventional gel imaging systems with a detection limit of 40 pg. This protocol is fast (hours) and does not require staining and destaining steps. The procedure is independent of plasminogen and, therefore, can efficiently distinguish the active two-chain uPA from its proenzyme. Densitometry analysis demonstrated a highly correlative relationship (r2=0.999) between the amount of uPA (over the range of 0.1-8.0 ng) and the average intensity of the fluorescent band. We were able to directly measure uPA activities in different cancer cell lines. This newly developed technique could be expanded to nearly all proteases, including the ones that cannot be analyzed by traditional zymography.

Solid phase assays in glycoconjugate research: applications to the analysis of proteoglycans, glycosaminoglycans and metalloproteinases

Glycoconjugates are a class of macromolecules consisting of different constituents, one of which is sugar moieties. Glycoconjugates comprise the majority of tissue constituents, both intracellular and extracellular. Extracellular glycoconjugates (glycoproteins and proteoglycans) participate in a wide variety of interactions, through which they maintain tissue integrity. Therefore, their analysis or the study of their possible interactions would give evidence for the state of tissues. Since the amounts of some of the extracellular glycoconjugates are usually low or the amounts of tissue to be examined come from biopsies, specific analytical systems are developed for their study, the most familiar being solid phase assays, which have the advantages of analysis of multiple samples on the same time, cheap instrumentation and high specificity.

Freshwater stingrays: study of epidemiologic, clinic and therapeutic aspects based on 84 envenomings in humans and some enzymatic activities of the venom

Freshwater stingrays are very common in the Paraná, Paraguay, Araguaia, and Tocantins Rivers and tributaries in Brazil. This study presents the clinical aspects of 84 patients injured by freshwater stingrays. Intense pain was the most conspicuous symptom. Skin necrosis was observed in a high percentage of the victims, mostly fishermen and bathers. The initial therapeutic procedures, like immersion of the affected member in hot water were effective in the initial phases of the envenoming, especially in the control of the acute pain; however, they did not prevent skin necrosis. By SDS-PAGE, the freshwater stingray (Potamotrygon falkneri) venom extract presented a major band of approximately 12 kDa. Several other components distributed between 15 and 130 kDa were detected in the venom extract. Many components with molecular mass above 80 and 100 kDa have gelatinolytic and caseinolytic activities, respectively. Hyaluronidase activity was detected only in a component around 84 kDa in P. falkneri venom extract. Our results demonstrated that the presence of these enzymes could explain partially the local clinical pictures presented by patients wounded by freshwater stingray.

Quantitative bead assay for hyaluronidase and heparinase I

A novel, simple, and sensitive assay was developed to monitor, quantitatively, the hyaluronidase and heparinase I-catalyzed cleavage of fluoresceinamine-labeled hyaluronic acid and heparin, respectively. The fluoresceinamine-labeled substrates were hydrophobically absorbed onto 4-microm polystyrene beads. In the presence of enzyme, the change in fluorescence output of the substrate-absorbed beads was monitored in a noncontinuous manner using a flow cytometer. Our results show that hyaluronidase and heparinase I can cleave their respective substrates on the beads in a concentration- and time-dependent manner. The assay is suitable for detecting the presence of these glycosaminoglycan-degrading enzymes in cell lysates, extracts, or purified fractions, for quantifying their amounts, and for investigating the activity of potential inhibitors.

Microanalysis of hyaluronan oligosaccharides by polyacrylamide gel electrophoresis and its application to assay of hyaluronidase activity

We established a rapid, sensitive polyacrylamide gel electrophoresis (PAGE) method for the analysis of hyaluronan (HA) oligosaccharides. Using mini-slab gels, but not large-slab gels so far reported, HA oligosaccharides of 5 to more than 50 repeating disaccharide units could be separated into discrete ladder-like bands in a short electrophoresis time of 45 min. Using a combined Alcian blue and silver staining protocol, the detection limit was less than 1 ng per band for 11 repeating disaccharide units, indicating 50 times higher sensitivity than that of an earlier-described sensitivity-enhanced PAGE method. Our PAGE method was applicable to the assay of hyaluronidase activity. When a total of multiple band intensities for 18-24 repeating disaccharide units was used as a measure of activity, as little as 3 x 10(-4) NFU of bovine testicular hyaluronidase was detectable on a 1-h incubation. This sensitivity permitted rapid measurements of human and rabbit serum hyaluronidases, the latter of which having never been detected even by a sensitive enzyme-linked immunosorbent assay (ELISA). Since this PAGE assay does not require specialized reagents and instruments and since it provides information on both the activity and the enzymatic HA degradation pattern, there may be many potential applications.

Use of a quartz crystal impedance technique to monitor the degradation of chondroitin sulfate by hyaluronidase

A new quartz crystal impedance hyaluronidase sensing technique, which is based on the changes in viscosity and density during the enzymatic hydrolysis of chondroitin sulfate (CS) by hyaluronidase (HAse), is established in this paper. The variations of equivalent circuit parameters of the piezoelectric quartz crystal (PQC) during the enzymatic degradation are discussed. The initial hydrolysis rate of CS by HAse is obtained from the changes in viscosity and density with incubation time. Kinetic parameters (the Michaelis constant K(m) and the maximum hydrolysis rate V(max)) of the degradation process are estimated by using a linear method of Lineweaver-Burk plot. K(m) is 2.73 +/- 0.20 mg.ml(-1) and V(max) is -(5.43 +/- 0.38) x 10(-4) kg.m(-2).s(-1/2).min(-1.)

Comparison of enzymatic activity from three species of necrotising arachnids in Australia: Loxosceles rufescens, Badumna insignis and Lampona cylindrata

Necrotising arachnidism, or skin ulceration due to spider bite, is an unresolved clinical problem in Australia, with both the spiders responsible and disease pathogenesis remaining unclear. We have examined and compared enzymic activity from three species of Australian spiders capable of causing ulceration in humans; the recluse spider (Loxosceles rufescens), the black window spider (Badumna insignis) and the white-tailed spider (Lampona cylindrata). Enzymes which could contribute to skin ulceration, namely hyaluronidase and proteases, were detected in venom extracts of all the three spiders. Significant sphingomyelinase activity was detected in L. rufescens venom and in abdominal extracts from the three spider species, while significantly lower levels of sphingomyelinase activity were detected in abdominal extracts from the non-necrosing red-back spider (Latrodectus hasselti). These results suggest that both venom and gastric enzymes may contribute to the dermonecrotic effects of these spiders bites.

Changes in protein composition and hydrolytic enzyme activity of Escherichia coli and Hafnia alvei grown in human fluids

Growing of Escherichia coli and Hafnia alvei cells in several cell-free human fluids, such as normal serum, serum from diabetic patients, pleural, ascitic and spinal fluid, revealed that various biochemical changes occurred. Protein profile on SDS-PAGE as well as acid and alkaline phosphohydrolytic enzymes on native gels of cell extracts were affected after culturing of bacteria in the above fluids. Gelatinolytic and hyaluronolytic activity was of interest because both of them are histolytic enzymes. Although there was a potential appearance of gelatinolytic bands on gelatin-SDS-PAGE in cells starved in seawater, none of these activities were expressed in cells grown in human fluids. A hyaluronolytic activity of approximately 45 KDa was present in cells cultured in Mueller Hinton broth. This enzyme was decreased either in cells starved in seawater or in cells grown in human fluids to an almost invisible band on hyaluronan-SDS-PAGE.

Mutations in HYAL1, a member of a tandemly distributed multigene family encoding disparate hyaluronidase activities, cause a newly described lysosomal disorder, mucopolysaccharidosis IX

Hyaluronan (HA), a large glycosaminoglycan abundant in the extracellular matrix, is important in cell migration during embryonic development, cellular proliferation, and differentiation and has a structural role in connective tissues. The turnover of HA requires endoglycosidic breakdown by lysosomal hyaluronidase, and a congenital deficiency of hyaluronidase has been thought to be incompatible with life. However, a patient with a deficiency of serum hyaluronidase, now designated as mucopolysaccharidosis IX, was recently described. This patient had a surprisingly mild clinical phenotype, including notable periarticular soft tissue masses, mild short stature, an absence of neurological or visceral involvement, and histological and ultrastructural evidence of a lysosomal storage disease. To determine the molecular basis of mucopolysaccharidosis IX, we analyzed two candidate genes tandemly distributed on human chromosome 3p21.3 and encoding proteins with homology to a sperm protein with hyaluronidase activity. These genes, HYAL1 and HYAL2, encode two distinct lysosomal hyaluronidases with different substrate specificities. We identified two mutations in the HYAL1 alleles of the patient, a 1412G --> A mutation that introduces a nonconservative amino acid substitution (Glu268Lys) in a putative active site residue and a complex intragenic rearrangement, 1361del37ins14, that results in a premature termination codon. We further show that these two hyaluronidase genes, as well as a third recently discovered adjacent hyaluronidase gene, HYAL3, have markedly different tissue expression patterns, consistent with differing roles in HA metabolism. These data provide an explanation for the unexpectedly mild phenotype in mucopolysaccharidosis IX and predict the existence of other hyaluronidase deficiency disorders.

Quantitation of hyaluronidases by the Morgan-Elson reaction: comparison of the enzyme activities in the plasma of tumor patients and healthy volunteers

The Morgan-Elson reaction, a method for the determination of hyaluronidase activity, was optimized for the quantitation of the enzyme in biological material. Based on HPLC and spectrometric (UV-Vis, LC-MS) studies, the structure of the red-colored product (mesomeric forms of N3-protonated 3-acetylimino-2-(4-dimethylaminophenyl)methylidene-5-(1,2-++ +dihydroxyethyl)furane) formed by condensation of chromogen III with p-dimethylaminobenzaldehyde is proposed. Activities corresponding to > or = 0.1 IU of endogenous and therapeutically administered hyaluronidase can be detected in 50 microl samples. Application of the method for the determination of the enzyme in plasma of tumor patients revealed no difference in activity levels, interindividual variability and pH profile compared to healthy volunteers.

Activity of hyaluronidase in placental tissues from cows with and without retained fetal membranes

Hyaluronidase, a proteoglycan-degrading enzyme, may have an influence on collagenolysis in bovine placenta and take part in the separation processes of the placenta in cows. There was, however, no evidence concerning the activity of this enzyme in those tissues. The experiment was performed on cows divided into two groups as follows: A, placenta not retained (n = 16); and B, placenta retained (n = 9). The activity of the enzyme was measured using a spectrophotometric method and zymography. The results showed statistically significant higher activity of hyaluronidase in the maternal and fetal parts of the placenta in cows with a retention of fetal membranes. Further experiments require substrate specificity studies and the presence of regulatory factors of this enzyme in bovine placental tissues.

Hyaluronic acid-specific regulation of cytokines by human uterine fibroblasts

The physiological inflammatory response can provide an effective mechanism for delivering the baby at the time of parturition. We characterized the mechanisms by which hyaluronic acid (HA) regulates interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and interleukin-8 (IL-8) production in human uterine fibroblasts. A dose-dependent increase in cytokine release was observed over an HA concentration range of 10 microg/ml to 1 mg/ml. The action of HA on the cytokine production is mediated by CD44. Under serum-free conditions, HA-induced cytokine generation was significantly less compared with production in the presence of serum, suggesting involvement of serum proteins. Addition of inter-alpha-trypsin inhibitor (ITI) under serum-free conditions enhanced the HA-induced synthesis of TNF-alpha, which stimulated the temporary release of IL-8. In addition, HA and IL-1beta stimulated the release of hyaluronidase by the fibroblasts. These results indicate that cytokine production in human uterine fibroblasts is regulated in a CD44-HA-ITI-specific fashion. HA may be involved in the regulation of delivery in part through the selective release of cytokines that contribute to uterine cervical ripening.

Electrophoretic analysis of hydrolytic enzymes of Escherichia coli cells starved in seawater and drinking water: comparison of gelatinolytic, caseinolytic, phosphohydrolytic and hyaluronolytic activities

Starvation of four Escherichia coli clinical strains in seawater and drinking water for nine days revealed that various changes of hydrolytic enzymes were induced. Several gelatinolytic and caseinolytic activities differing in mol mass were detected both in seawater and drinking water starved cells by substrate gel electrophoresis. The major activities of gelatinase migrated with mol masses of approximately 170 kDa and approximately 45 kDa. On the contrary, hyaluronolytic activities were detected only in cells cultured in Mueller Hinton broth with average mol masses of 36 kDa and 45 kDa. Acid and alkaline phosphohydrolytic activities were detected by native electrophoresis. Both activities were decreased in number of bands in E. coli cells starved either in seawater or drinking water.