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)

Hyaluronidases are endo-glycosidases that degrade both hyaluronan (hyaluronic acid) (HA) and chondroitin sulfates. Deficiency of hyaluronidase activity has been predicted to result in a phenotype similar to that observed in mucopolysaccharidosis (MPS). In the present study, we surveyed a variety of patients with phenotypes similar to those observed in MPS, but without significant mucopolysacchariduria to determine if some are based on aberrations in serum hyaluronidase (Hyal-1) activity. The study included patients with well-characterized dysmorphic disorders occurring on genetic basis, as well as those of unkown etiology. The purpose of the study was to establish how wide spread were abnormalities in levels of circulating Hyal-1 activity. A simple and sensitive semi-quantitative zymographic procedure was used for the determination of activity. Levels of both beta-N-acetylglucosaminidase and beta-glucuronidase whose activities contribute to the total breakdown of hyaluronan (HA) were also measured, as well as the concentration of circulating HA. Among 48 patients with bone or connective tissue abnormalities, low levels of Hyal-1 activity were found in six patients compared to levels in 100 healthy donors (2.0-3.2 units/microL vs 6(+/- 1 SE) units/microL). These six patients exhibited a wide spectrum of clinical abnormalities, in particular shortened extremities: they included three patients with unknown causes of clinical symptoms, one patient with Sanfilippo disease, one of the seven patients with achondroplasia, and one with hypophosphotemic rickets. Normal levels of serum Hyal-1 activities were found in patients with Morquio disease, GM1 gangliosidosis, I cell-disease, 6 of the 7 patients with achondroplasia, Marfan's-syndrome and Ehlers-Danlos syndrome. No patient totally lacked serum Hyal-1 activity. Serum HA concentration was elevated in patients with Sanfilippo A and I-cell disease. Determination of serum and leukocyte Hyal-1 and serum HA may be useful to evaluate patients with metabolic and morphogenetic disorders.
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PMID:Serum hyaluronidase aberrations in metabolic and morphogenetic disorders. 1631 83

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.
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PMID:A mouse model of human mucopolysaccharidosis IX exhibits osteoarthritis. 1834 57

The metabolism of hyaluronan (HA) relies on HA synthases and hyaluronidases, among which hyaluronidase-1 (HYAL1) and -2 (HYAL2) have been proposed as key actors. Congenital HYAL1 deficiency leads to mucopolysaccharidosis IX (MPS IX), a rare lysosomal storage disorder characterized by joint abnormalities. Knowledge of HYAL2 is limited. This protein displays weak in vitro hyaluronidase activity and acts as a receptor for oncogenic ovine retroviruses. We have generated HYAL2-deficient mice through a conditional Cre-lox system. Hyal2(-/-) mice are viable and fertile. They exhibit localized congenital defects in frontonasal and vertebral bone formation and suffer from mild thrombocytopenia and chronic, possibly intravascular, hemolysis. In addition, Hyal2(-/-) mice display 10-fold increases in plasma levels of HA and 2-fold increases in plasma hyaluronidase activity. Globally, there is no HA accumulation in tissues, including bones, but liver sinusoidal cells seem overloaded with undigested HA. Taken together, these elements demonstrate for the first time that murine HYAL2 has a physiological activity in vivo that is relevant for craniovertebral bone formation, maintenance of plasma HA concentrations, and erythrocyte and platelet homeostasis. In addition, the viability of HYAL2-deficient mice raises the possibility that a similar defect, defining a new MPS disorder, exists in humans.
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PMID:Skeletal and hematological anomalies in HYAL2-deficient mice: a second type of mucopolysaccharidosis IX? 1877 48