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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)
Fetal skin fibroblasts migrate into 3D collagen gels to a significantly greater extent than do adult cells. This enhanced motility of fetal fibroblasts appears to result from the production of a "migration stimulating factor" (MSF) which is not made by their normal adult counterparts. Adult skin fibroblasts retain responsiveness to MSF and cells exposed to this factor achieve the elevated levels of migration characteristic of fetal cells. MSF has been purified to homogeneity, has an apparent molecular mass of 70 kD and has been further characterized in terms of a number of biochemical parameters. Studies concerned with the mechanism of action of MSF indicate that it stimulates the production of a high molecular weight class of hyaluronic acid (HA). Concurrent exposure of cells to Streptomyces
hyaluronidase
blocks the stimulation of adult fibroblast migration by MSF. In a related series of experiments, we have shown that
TGF-beta
inhibits the effects of MSF on both cell migration and HA production. Taken together, these data suggest that the stimulation of fibroblast migration by MSF is dependent upon (and may directly result from) a primary induction of HA synthesis. We have previously reported that skin fibroblasts obtained from patients with sporadic and familial breast cancer, as well as the unaffected first-degree relatives of familial breast cancer patients, commonly display a fetal-like migratory phenotype. Subsequent work has indicated that (a) these fetal-like cells also produce MSF, and (b) detectable levels of MSF are present in the serum of sporadic breast cancer patients both prior to and following surgical resection of the primary tumor mass. On the basis of these and related observations, we have put forward an hypothesis suggesting that the disruption in normal epithelial-mesenchymal interactions caused by the persistent production of MSF by fibroblasts in the adult may contribute directly to the pathogenesis of an epithelial cancer. The demonstration of aberrant fibroblasts in sporadic cancer patients (both in our own and independent studies) is not consistent with the "germ-line genetic lesion" model commonly invoked to account for the presence of such cells in patients with hereditary cancer syndromes.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Heterogeneity amongst fibroblasts in the production of migration stimulating factor (MSF): implications for cancer pathogenesis. 183 26
A polyclonal antibody (CL-B1/29) raised against a synthetic peptide with an amino acid sequence identical to the first 29 N-terminal residues of bovine bone-derived transforming growth factor-beta 2 (
TGF-beta
2) was characterized and used for immunolocalization of
TGF-beta
2 in adult mice. Reduced staining of immunoblots and tissue after absorption of the antiserum with the immunizing peptide or with
TGF-beta
2 but not with purified
TGF-beta
1 demonstrated that the reagent is specific for
TGF-beta
2, with little or no crossreactivity with
TGF-beta
1. The immunolocalization of
TGF-beta
2 was investigated in formalin-fixed, paraffin-embedded cultured cells and murine tissue. Specimens pre-digested with testicular
hyaluronidase
demonstrated immunostaining predominantly of extracellular connective tissue matrix, whereas specimens pre-digested with pronase E demonstrated primarily cytoplasmic staining. Immunoreactivity was widely distributed in connective tissue, muscle, adsorptive and secretory epithelia, especially of endocrine tissue, and neural tissue of adult mice.
...
PMID:A novel polyclonal antibody (CL-B1/29) for immunolocalization of transforming growth factor-beta 2 (TGF-beta 2) in adult mouse. 225 47
Both
hyaluronidase
and transforming growth factor (TGF)-beta 1 play a significant role in the development of prostate cancer. In this study, the regulation of tumor necrosis factor (TNF)-mediated cell death by
hyaluronidase
and
TGF-beta
1 was investigated. Preexposure of L929 fibroblasts, prostate LNCaP cells, and epithelial Mv 1 Lu cells to
hyaluronidase
for a minimum of 12 h resulted in significant enhancement of cell death by TNF. Phosphorylation of p42 and p44 mitogen-activated-protein (MAP) kinases was found by stimulation of L929 cells with
hyaluronidase
for 30 min, indicating that the Raf/MAP kinase-extracellular signal-regulating protein kinase (MEK)/ MAP kinase pathway was activated. However, blocking the activation of upstream MAP kinase kinase (MEK 1 and 2 kinase) by PD-98059 failed to inhibit the
hyaluronidase
-enhanced TNF killing of cells, suggesting that
hyaluronidase
-mediated degradation of extracellular matrix and membrane components may elicit multiple signaling pathways. As a potent stimulator of extracellular matrix protein synthesis,
TGF-beta
1 blocked the
hyaluronidase
-enhanced death of L929 and LNCaP cells mediated by TNF.
TGF-beta
1 activated protein-tyrosine kinases in L929 cells, in which the tyrosine kinase inhibitors lavendustin A and tyrphostin blocked the activation as well as the
TGF-beta
1 inhibition of
hyaluronidase
effects. Functional antagonism was also observed between
hyaluronidase
and
TGF-beta
1 in cell growth regulation. For example,
TGF-beta
1-mediated suppression of epithelial Mv 1 Lu cell growth was abolished by
hyaluronidase
. Overall, it is demonstrated in this study that
hyaluronidase
reciprocally antagonized
TGF-beta
1 in the modulation of cell proliferation and TNF-mediated death.
...
PMID:Hyaluronidase enhancement of TNF-mediated cell death is reversed by TGF-beta 1. 943 5
Mitf encodes a basic helix-loop-helix-leucine-zipper (bHLHzip) protein that is known to function in the development of melanocytes, pigmented epithelial cells (PECs), osteoclasts, and mast cells. In this paper, we report on the isolation, expression, and overexpression of the chicken Mitf and discuss the role of its protein product in the differentiation and transdifferentiation of PECs. Northern blotting showed that chicken Mitf is predominantly expressed in embryonic retinal pigmented epithelium (PE), but is expressed at low levels in other tissues. A 5' RACE analysis revealed differences in the 5' region Mitf nRNA in PE and other tissues. Immunological analysis revealed that Mitf, the protein encoded by Mitf, is first detected in the nuclei of the optic vesicle cells at embryonic stage 13 in a restricted region covered with mesenchymal cells. From stage 14 to 24, the specific staining is observable in the PE and precursor of the PE, the outer layer of the optic cup. In embryos at stages later than stage 29 the signals for Mitf in the future iris, ciliary body, and posterior retinal regions become faint. These results show that expression of Mitf starts at the optic vesicle stage at which no other marker genes for PECs such as mmp115 and tyrosinase are expressed. Dedifferentiation of cultured retinal PECs (rPECs) was induced by phenylthiourea and testicular
hyaluronidase
, bFGF, or
TGF-beta
. Mitf expression was inhibited by these factors and reactivated during redifferentiation of the dedifferentiated cells into rPECs, showing the correlation between Mitf expression and rPEC differentiation. Retrovirus-mediated overexpression of Mtif inhibited bFGF-induced dedifferentiation and transdifferentiation of rPECs to both lens and neural cells. These findings showed that downregulation of Mitf expression is essential for the transdifferentiation of rPEC. Mitf overexpression caused hyperpigmentation in cultured rPECs and suppressed the changes in gene expression induced by bFGF. Mitf overexpression promoted expression of mmp115 and tyrosinase in bFGF-treated rPECs suggesting a critical role for Mitf in rPEC differentiation. Mitf overexpression, however, did not promote expression of another rPEC-specific gene, pP344, in bFGF-treated rPECs. This result suggests the presence of other regulatory genes promoting rPEC differentiation. The expression patterns of pax6 and Mitf are complementary both in vivo in vitro. Overexpression of Mitf inhibited expression of pax6 in cultured rPECs. These observations suggest that Mitf regulates pax6 expression negatively.
...
PMID:Role of Mitf in differentiation and transdifferentiation of chicken pigmented epithelial cell. 946 87
We have recently demonstrated that the three principal mammalian isoforms of transforming growth factor beta (TGF-beta) exert distinct effects upon: (1) the migration of confluent adult fibroblasts into 3D gels of native type I collagen fibres (i.e.
TGF-beta-1
and -2 had no apparent motogenic activity, whilst TGF-beta-3 induced a dose-dependent stimulation of cell migration); and (2) the synthesis of hyaluronan (HA) by these cells is also affected by the TGF-beta isoforms in a manner which parallels their effect on cell migration. The objective of the present study is to elucidate the manner in which this differential activity of the
TGF-beta-1
, -2 and -3 may be modulated by experimental parameters. Data presented in this communication indicate that cytokine bioactivity is determined by a combination of cell density and the nature of the macromolecular substratum. Thus, we now report that all three TGF-beta isoforms inhibit the migration of subconfluent cells in the collagen gel assay. Our data confirm that the migration of confluent cells is stimulated by TGF-beta-3 and further indicate that this motogenic activity is completely abrogated by either
TGF-beta-1
or -2 when these are co-incubated with TGF-beta-3. In contrast to these results obtained using a native type I collagen substratum, all three isoforms stimulated adult fibroblast migration in the transmembrane assay (in which cells are adherent to a 2-D porous polycarbonate substratum). The precise effect of TGF-beta isoforms on HA synthesis was also affected by cell density and the nature of the substratum in a manner which paralleled their diverse effects on cell migration (i.e. stimulation, inhibition or no effect). Streptomyces
hyaluronidase
completely neutralized the TGF-beta-3-induced stimulation of confluent fibroblast migration, thus suggesting a mechanistic link between the cytokine-induced cell migration and HA synthesis under these conditions. Taken together, these data indicate that: (1) the bioactivity of
TGF-beta-1
, -2 and -3 are determined by cell density, the macromolecular substratum and the presence of other cytokines; and (2) it is therefore necessary to define cytokine bioactivity within the context of a larger 'tissue response unit' which more fully defines the activity state of the target cell and its microenvironment.
...
PMID:Motogenic and biosynthetic response of adult skin fibroblasts to TGF-beta isoforms (-1, -2 and -3) determined by 'tissue response unit': role of cell density and substratum. 1072 70
Our previous study reported that
TGF-beta
may be isolated from human Wharton's jelly (WJ) in a form of soluble, high molecular complex(es). We decided to study the effect of extracellular matrix degradation and reduction of disulphide bridges reduction on the release of
TGF-beta
from WJ. The WJ prepared from the umbilical cords of newborns delivered at term by healthy mothers was homogenised and treated with
hyaluronidase
, collagenase, heparinase, chondroitinase and beta-mercaptoethanol, the resulting extracts were then submitted to
TGF-beta
immunoassay and SDS/PAGE followed by Western immunoblotting. The effect of metalloproteinase activation on
TGF-beta
was also studied. Pre-treatment of WJ homogenates with
hyaluronidase
or collagenase markedly increased the extractability of
TGF-beta
, but did not dissociate the complexes. In contrast, the action of beta-mercaptoethanol resulted in the release of free
TGF-beta
; but activation of metalloproteinases resulted in the disappearance of this factor. We conclude that TGF-beta1 is bound through disulphide bonds to an extracellular matrix component of WJ. The large amount of collagen fibrils and hyaluronate molecules which surround the cells scattered in WJ may prevent the access of extracting solution to
TGF-beta
causing a low extractability of this factor. Although hyaluronate and collagen do not bind
TGF-beta
directly, they may present a barrier that prevents the diffusion of
TGF-beta
in WJ and results in its concentration around the cells thereby facilitating its interaction with membrane receptors and subsequent stimulation of cell division and synthesis of extracellular matrix components.
...
PMID:TGF-beta binding in human Wharton's jelly. 1821 41