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)

We have detected the presence of nuclear 3,5,3'-triiodothyronine (T3) receptors in primary cultures of chick embryo hepatocytes and neurons. Hepatocytes were isolated from livers of embryos of 12, 16 and 19 days by treatment with 0.2% collagenase and hyaluronidase. They were plated at a density of 3-4 x 10(5)/35-mm petri dish in Ham's F-10 medium containing fetal calf serum, tryptose phosphate, and antibiotics. Cells were used for the binding assay at Day 3 of culture. Neurons from 8-day-old embryo brains were cultured in a serum-free medium at a density of 1.2 x 10(6) cells/35-mm petri dish and used for the binding assay after 7 days of culture. Biological activity of hepatocytes was determined by measuring insulin binding, inositol phosphate formation, and 5'-monodeiodinase activity. Neurons or glial cells in culture were identified by immunostaining with anti-neurofilaments and anti-glial fibrillary acidic protein antisera. Binding assay was performed with isolated nuclei and 0.4 M NaCl nuclear extracts. With the latter preparation, the Scatchard analysis showed, in both cells, a single, high-affinity, low-capacity T3 receptor. In the hepatocytes of 12-, 16-, and 19-day-old embryos association constants (Ka) were, respectively, 0.93 +/- 0.02, 0.74 +/- 0.03, and 0.56 +/- 0.04 nM-1, whereas the maximal binding capacities (MBC) were 2.26 +/- 0.2, 2.72 +/- 0.33, and 1.83 +/- 0.19 fmol/microgram DNA (mean +/- SE, n = 3). In neurons Ka was 1.25 +/- 0.53 nM-1 and MBC 0.59 +/- 0.14 fmol/microgram DNA (n = 3). The receptor had a sedimentation coefficient of 3.4 S, an estimated Mr of 59 kDa, and the following relative affinity for thyroid hormone analogues: TRIAC greater than L-T3 greater than L-T4. These data indicate that cultured hepatocytes and neurons of chick embryo contained T3 receptors with properties similar to those described in intact tissues from this and other species. Only the MBC of neurons was 50% lower than that observed in whole brain of embryo, but was comparable to values observed in cultured neurons from other species.
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PMID:Characterization of 3,5,3'-triiodothyronine receptors in primary cultures of hepatocytes and neurons from chick embryo. 160 Dec 52

Because the dermis of myxedematous humans is known to accumulate increased amounts of glycosaminoglycan (GAG), we were prompted to study the effects of thyroid hormone depletion in vitro. Human skin fibroblasts were grown to confluence in medium containing 10% fetal calf serum (FCS). Some cultures were shifted to a medium containing FCS depleted of thyroid hormone (D-FCS) or to a D-FCS medium to which 10(-7) M triiodothyronine (T3) was added (D-FCS + T3). Cultures were then labeled for 16 h with [3H]-acetate, harvested and combined with the media. After pronase digestion, the non-trichloroacetic acid precipitable, non-dialysable material was digested with streptomyces hyaluronidase followed by chondroitinase ABC. Digestable material was separated by G-50 Sephadex column chromatography. The cultures incubated in media containing D-FCS accumulated 2.8-fold more hyaluronic acid and 2.1-fold more chondroitin sulfate than did sister cultures incubated in the presence of D-FCS + T3. The addition of T3 to the D-FCS reduced the amounts of GAG accumulated nearly to the levels observed in cultures grown in FCS. The data indicate that thyroid hormone exerts an inhibitory effect on GAG accumulation in human skin fibroblasts. This model offers the opportunity to study thyroid hormone action in vitro using an easily accessible human tissue.
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PMID:The effect of thyroid hormone on glycosaminoglycan accumulation in human skin fibroblasts. 722 12

A case of dermal mucinosis and musculoskeletal symptoms simulating polymyositis as a presenting sign of hypothyroidism is presented. The patient presented muscle weakness and edema of the face including the eyelids. Laboratory examination revealed elevated creatinine phosphokinase, decreased free-T4, decreased free-T3, elevated TSH, positive anti-microsome antibody and positive anti-TSH receptor antibody. The skin biopsy specimen revealed swelling of the collagen bundles with the bundles splitting up into individual fibers, with some blue threads and granules of mucin interspersed. Alucian blue stain demonstrated vast amounts of mucin throughout the whole dermis, which was completely removed on incubation with Streptomyces hyaluronidase. The patient was diagnosed as having hypothyroidism due to Hashimoto's disease with possible polymyositis complications. After two months of thyroid hormone replacement therapy, she was euthyroidic and discharged. These results indicate that our case was a rare case of severe generalized myxoedema due to hypothyroidism of Hashimoto's disease simulating the musculoskeletal symptoms of polymyositis.
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PMID:Dermal mucinosis and musculoskeletal symptoms simulating polymyositis as a presenting sign of hypothyroidism. 1021 Jul 91

In this study, the effect of thyroid hormone (triiodothyronine, T(3)) on the secretion of mitogenic growth factors in astrocytes and C6 glioma cells was examined. The proliferating activity of T(3) could be due, at least in part, to the astrocyte secretion of acidic and basic fibroblast growth factor (aFGF and bFGF), tumor necrosis factor-beta, and transforming growth factor-beta. In contrast, the conditioned medium (CM) of T(3)-treated C6 cells was mitogenic to this cell line only after hyaluronidase digestion, suggesting the impairment of growth factor mitogenic activity by hyaluronic acid. Furthermore, the presence of bFGF was significantly greater in the CM of both T(3)-treated astrocytes and T(3)-treated C6 cells than in the corresponding control CM. These data show that T(3) induces cerebellar astrocytes to secrete mitogenic growth factors, predominantly bFGF, that could influence astrocyte and neuronal proliferation via autocrine and paracrine pathways.
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PMID:Thyroid hormone induces cerebellar astrocytes and C6 glioma cells to secrete mitogenic growth factors. 1159 67