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Query: EC:3.4.24.3 (
collagenase
)
18,340
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
alpha-Tocopherol modulates two major signal transduction pathways centered on protein kinase C and phosphatidylinositol 3-kinase. Changes in the activity of these key kinases are associated with changes in cell proliferation, platelet aggregation, and NADPH-oxidase activation. Several genes are also regulated by tocopherols partly because of the effects of tocopherol on these two kinases, but also independently of them. These genes can be divided in five groups: Group 1. Genes that are involved in the uptake and degradation of tocopherols: alpha-tocopherol transfer protein, cytochrome P450 (CYP3A), gamma-glutamyl-cysteine synthetase heavy subunit, and glutathione-S-transferase. Group 2. Genes that are implicated with lipid uptake and atherosclerosis: CD36, SR-BI, and SR-AI/II. Group 3. Genes that are involved in the modulation of extracellular proteins: tropomyosin, collagen-alpha-1,
MMP-1
, MMP-19, and connective tissue growth factor. Group 4. Genes that are connected to adhesion and inflammation: E-selectin, ICAM-1 integrins, glycoprotein IIb, IL-2, IL-4, IL-1b, and
transforming growth factor-beta
(
TGF-beta
). Group 5. Genes implicated in cell signaling and cell cycle regulation: PPAR-gamma, cyclin D1, cyclin E, Bcl2-L1, p27, CD95 (APO-1/Fas ligand), and 5a-steroid reductase type 1. The transcription of p27, Bcl2, alpha-tocopherol transfer protein, cytochrome P450 (CYP3A), gamma-glutamyl-cysteine sythetase heavy subunit, tropomyosin, IL-2, and CTGF appears to be upregulated by one or more tocopherols. All the other listed genes are downregulated. Gene regulation by tocopherols has been associated with protein kinase C because of its deactivation by alpha-tocopherol and its contribution in the regulation of a number of transcription factors (NF-kappaB, AP1). A direct participation of the pregnane X receptor (PXR) / retinoid X receptor (RXR) has been also shown. The antioxidant-responsive element (ARE) and the
TGF-beta
-responsive element (TGF-beta-RE) appear in some cases to be implicated as well.
...
PMID:Vitamin E mediates cell signaling and regulation of gene expression. 1575 36
Although the chemopreventive and antitumorigenic activities of nonsteroidal anti-inflammatory drug (NSAID) against colorectal cancer are well established, the molecular mechanisms responsible for these properties in ovarian cancer have not been elucidated. Therefore, there is an urgent need to develop mechanism-based approaches for the management of ovarian cancer. To this end, the effect of several NSAIDs on ovarian cancer cells was investigated as assessed by the induction of NAG-1/MIC-1/GDF-15, a proapoptotic gene belonging to the
transforming growth factor-beta
superfamily. Sulindac sulfide was the most significant NSAID activated gene 1 (NAG-1) inducer and its expression was inversely associated with cell viability as determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. This growth suppression by sulindac sulfide was recovered by transfection of NAG-1 small interfering RNA. These results indicate that NAG-1 is one of the genes responsible for growth suppression by sulindac sulfide. Furthermore, we observed down-regulation of p21 WAF1/CIP1 by introduction of NAG-1 small interfering RNA into sulindac sulfide-treated cells. In addition, to elucidate other potential molecular mechanisms involved in sulindac sulfide treatment of ovarian cancer cells, we did a membrane-based microarray experiment. We found that cyclin D1,
MMP-1
, PI3KR1, and uPA were down-regulated by sulindac sulfide. In conclusion, a novel molecular mechanism is proposed to explain the experimental results and provide a rationale for the chemopreventive activity of NSAIDs in ovarian cancer.
...
PMID:The conventional nonsteroidal anti-inflammatory drug sulindac sulfide arrests ovarian cancer cell growth via the expression of NAG-1/MIC-1/GDF-15. 1576 58
Recent data demonstrate the fundamental role of endothelin in the pathogenesis of fibrosis, and the anti-fibrotic potential of dual endothelin receptor antagonists such as bosentan. Although
transforming growth factor-beta
, aldosterone and connective tissue growth factor, have already been established as contributors to the process of fibrosis, endothelin now emerges as a key player, which may have a role both in the initiation and in maintenance of fibrosis, and may mediate the pro-fibrotic effects of the other agents. Bosentan is an orally active, dual endothelin receptor antagonist, which competitively antagonizes the binding of endothelin to both endothelin receptors ETA and ETB. Bosentan prevents endothelin-induced fibroblast proliferation and extracellular matrix deposition and contraction, and reduces cardiac, hepatic, pulmonary and renal fibrosis in different disease models characterized by the activation of the endothelin system. Bosentan even reverses existing fibrosis, possibly by its effect of stimulating matrix metalloproteinase type 1 (
collagenase
) expression. The anti-fibrotic effects of bosentan extend to fibrosis induced by mediators other than endothelin such as
transforming growth factor-beta
, angiotensin II and aldosterone, indicating a central role of endothelin and endothelin receptors in fibrotic processes.
...
PMID:Role of endothelin in fibrosis and anti-fibrotic potential of bosentan. 1590 42
Liver fibrosis and cirrhosis involve multiple cellular and molecular events that lead to deposition of an excess of extracellular matrix proteins and increase the distortion of normal liver architecture. Etiologies include chronic viral hepatitis, alcohol abuse and drug toxicity. Degradation of these matrix proteins occurs predominantly as a result of a family of enzymes called metalloproteases (MMPs) that specifically degrade collagenous and non-collagenous substrates. Matrix degradation in the liver is due to the action of at least four of these enzymes:
MMP-1
, MMP-2, MMP-3 and MMP-9. In the fibrinolytic system, MMPs can be activated through proteolytic cleavage by the action of urokinase plasminogen activator; a second mechanism includes the same metalloproteases. This activity is regulated at many levels in the fibrinolytic system. The main regulator is the PAI-1. This molecule blocks the conversion of plasminogen into plasmin, and the MMP cannot be activated. At a second level, the inhibition is possible by binding to inhibitors called TIMP that can inhibit the proteolitic activity even when the MMPs had been previously activated by plasmin. During abnormal conditions, overexpression of these inhibitors is directed by the
transforming growth factor-beta
that in a fibrotic disease acts as an extremely important adverse factor.
...
PMID:[Hepatic fibrosis: role of matrix metalloproteases and TGFbeta]. 1616 29
1.--The immunomodulating agent FTY720 is a substrate for the sphingosine kinase and the phosphorylated form is able to bind to sphingosine 1-phosphate (S1P) receptors. In this study, we show that exposure of renal mesangial cells to phospho-FTY720 leads to a rapid and transient activation of several protein kinase cascades, including the mitogen- and stress-activated protein kinases. The nonphosphorylated FTY720 also increased MAPK phosphorylation, but with a reduced potency and a more delayed time course. In addition, phospho-FTY720 and FTY720 are able to increase phosphorylation of Smad proteins which are classical members of the
transforming growth factor-beta
(
TGF-beta
) signalling device, thus suggesting a crosstalk between FTY720 and
TGF-beta
signalling. 2.--Pretreatment with the S1P(3) receptor antagonist suramin inhibits FTY720 and phospho-FTY720-induced Smad phosphorylation, whereas pertussis toxin pretreatment, which blocks G(i/0) proteins, has no effect on Smad phosphorylation. 3.--Since
TGF-beta
is a potent profibrotic cytokine in mesangial cells and upregulates the connective tissue growth factor (CTGF) and collagen as important hallmarks in the fibrotic sequelae, we investigated whether FTY720 and phospho-FTY720 are able to mimic these effects of
TGF-beta
. Indeed, FTY720 and phospho-FTY720 markedly upregulate CTGF and collagen type IV protein expressions. In addition, the tissue inhibitor of
metalloproteinase-1
is transcriptionally activated by FTY720, whereas cytokine-induced matrix metalloproteinase-9 is down-regulated by FTY720. 4.--Depletion of the TGF-beta receptor type II by the siRNA transfection technique blocks not only Smad phosphorylation but also CTGF upregulation. Similarly, Smad-4 depletion by siRNA transfection also abrogates CTGF upregulation induced by FTY720 and phospho-FTY720. 5.--In summary, our data show that FTY720 and phospho-FTY720 not only activate the Smad signalling cascade in mesangial cells, but also upregulate the expression of CTGF and collagen. These findings suggest that FTY720 may have additional effects besides the established immunomodulatory action and, importantly, a profibrotic activity has to be considered in future experimental approaches.
...
PMID:The immunomodulator FTY720 and its phosphorylated derivative activate the Smad signalling cascade and upregulate connective tissue growth factor and collagen type IV expression in renal mesangial cells. 1629 53
Increased inflammatory activity is known to accompany aging. Single nucleotide polymorphisms of inflammatory mediator genes might therefore affect the aging process. Relation of eight SNPs (tumor necrosis factor-alpha [TNF-alpha] -1031 T/C, interleukin-10 [IL-10] -819 T/C, IL-1beta -511 C/T, IL-6 -634 C/G, IL-18 -607 A/C,
transforming growth factor-beta
[TGF-beta] +869 C/T,
matrix metalloproteinase-1
[
MMP-1
] -1607 1G/2G, and MMP-3 -1171 5A/6A) with age or gender was evaluated in 500 Japanese persons (mean age: 56.7 years old, range: 19-100) by the chi-square test. There was a significant association of IL-10 -819 T/C with age (p =.0026). The association remained significant after multivariate logistic regression analysis (odds ratio for an age interval for 1 year, 1.009; 95% CI, 1.002-1.016). Furthermore, the genotype distribution of IL-10 -819 T/C was completely consistent with that of -592 A/C. These data suggest that IL-10 -819 T/C and -592 A/C may be a promising candidate for an aging-related gene in a Japanese population.
...
PMID:Association of interleukin-10 promoter single nucleotide polymorphisms -819 T/C and -592 A/C with aging. 1642 84
The hypothesis was tested that bovine preantral follicles can be stimulated to grow in vitro by FSH and by the mitogens, epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF), but not by
transforming growth factor-beta
(
TGFbeta
), which generally inhibits EGF and bFGF action. Preantral follicles, 60 to 179 mum in diameter, were isolated from fetal ovaries by treatment with
collagenase
and DNase and cultured for 6 d in serum-free medium, with or without FSH and growth factors. Basic FGF (50 ng/ml), and to a lesser extent FSH (100 ng/ml) and EGF (50 ng/ml), stimulated thymidine incorporation by granulosa cells in bovine preantral follicles compared to control cultures (8-, 4- and 2.5-fold the labeling index of the controls; P < 0.05). Alone
TGFbeta
(10 ng/ml) had no effect on (3)H-thymidine incorporation, but it completely inhibited the bFGF- but not the FSH-stimulated increase in the labeling index and mean follicular diameter of preantral follicles (P < 0.05). By the end of the culture period oocytes in most treatments had degenerated, and the few surviving oocytes were in preantral follicles cultured with FSH or bFGF. Progesterone accumulation was greater (P < 0.05) in the presence of FSH (100 ng/ml) or EGF (50 ng/ml) than with bFGF,
TGFbeta
or control medium. Basic FGF strongly inhibited the effect of FSH on progesterone secretion (P < 0.05). Only FSH stimulated the conversion of exogenous testosterone to estradiol and both bFGF and
TGFbeta
markedly inhibited FSH-stimulated estradiol accumulation. These results indicate that proliferation of granulosa cells of bovine preantral follicles can be stimulated by bFGF, FSH and EGF, whereas
TGFbeta
inhibits growth, and that they are steroidogenically active in culture. Basic FGF and
TGFbeta
antagonize FSH-stimulated steroid production by granulosa cells of cultured bovine preantral follicles.
...
PMID:FSH and growth factors affect the growth and endocrine function in vitro of granulosa cells of bovine preantral follicles. 1672 44
Transparency is essential for normal corneal function. Recent studies suggest that corneal cells express high levels of so-called corneal crystallins, such as aldehyde dehydrogenase (ALDH) and transketolase (TKT) that contribute to maintaining cellular transparency. Stromal injury leads to the appearance of repair phenotype keratocytes, the corneal fibroblast and myofibroblast. Previous studies on keratocytes from species such as bovine and rabbit indicate that the transformation from the normal to repair phenotype is accompanied by a loss of corneal crystallin expression, which may be associated with loss of cellular transparency. Here we investigated if a similar loss occurs with human keratocyte repair phenotypes. Human corneal epithelial cells were collected by scraping and keratocytes were isolated by
collagenase
digestion from cadaveric corneas. The cells were either processed immediately (freshly isolated keratocytes) or were cultured in the presence of 10% fetal bovine serum or
transforming growth factor-beta
to induce transformation to the corneal fibroblast and myofibroblast phenotypes, respectively. RT-PCR, western blotting and immunolabeling were used to detect mRNA and protein expression of ALDH isozymes and TKT. ALDH enzyme activity was also quantitated and immunolabeling was performed to determine the expression of ALDH3A1 in human corneal tissue sections from normal and diseased corneas. Human corneal keratocytes isolated from three donors expressed ALDH1A1 and ALDH3A1 mRNA, and one donor also expressed ALDH2 and TKT. Corneal epithelial cells expressed ALDH1A1, ALDH2, ALDH3A1 and TKT. Compared to normal keratocytes, corneal fibroblast expression of ALDH3A1 mRNA was reduced by 27% (n=5). ALDH3A1 protein expression as detected by western blotting was markedly reduced in passage zero fibroblasts and undetectable in higher passages (n=3). TKT protein expression was reduced in fibroblasts compared to keratocytes (n=2). ALDH3A1 enzyme activity was not detectable in corneal fibroblasts (n=6) but was readily detected in corneal epithelial cells (0.29+/-0.1U/mg protein, n=4) and keratocytes (0.05+/-0.009U/mg protein, n=7). ALDH3A1 expression was also reduced in corneal fibroblasts and myofibroblasts as determined by immunolabeling of the cells in culture (n=3) and in diseased corneal tissues in situ (n=2). We conclude that expression of the crystallin ALDH3A1 is decreased in repair phenotype human keratocytes, compared to normal human keratocytes. Extrapolating from studies of bovine and rabbit, the reduced expression of ALDH3A1 may contribute to the loss of corneal transparency experienced by human patients after injury and refractive surgeries.
...
PMID:Aldehyde dehydrogenase (ALDH) 3A1 expression by the human keratocyte and its repair phenotypes. 1682 7
Alterations of human skin connective tissue structure and function are prominent features of chronological aging and solar UV irradiation-induced premature aging (photoaging). These skin connective tissue abnormalities result, in part, from reduced synthesis and elevated degradation of type I collagen, the major structural protein in skin. Here, we report that cysteine-rich 61 (CYR61/CCN1), a novel mediator of collagen homeostasis, is predominantly expressed in human skin connective tissue and is significantly elevated in fibroblasts in chronologically aged (80+ years) and photoaged human skin in vivo. In cultured human skin fibroblasts, elevated CYR61 expression substantially reduces type I procollagen and concurrently increases
matrix metalloproteinase-1
(
MMP-1
), which initiates fibrillar collagen degradation. Elevated CYR61 caused down-regulation of transforming growth factor-beta type II receptor mRNA and protein levels, thereby impairing the
transforming growth factor-beta
pathway, which reduced type I procollagen and raised
MMP-1
expression. Furthermore, elevated CYR61 induced transcription factor activator protein-1 (AP-1), which functions to stimulate
MMP-1
expression. Thus, elevated expression of CYR61 in human skin fibroblasts acts through multiple pathways to cause alterations of collagen homeostasis similar to those pathways observed in aged human skin in vivo. These data identify CYR61 as a pivotal regulator of collagen production and degradation in aged and photoaged human skin.
...
PMID:Elevated cysteine-rich 61 mediates aberrant collagen homeostasis in chronologically aged and photoaged human skin. 1687 50
Glomerulosclerosis, interstitial fibrosis, and tubular atrophy occur with end-stage kidney failure, irrespective of the primary etiology. The
transforming growth factor-beta
(
TGF-beta
) is a key factor in these alterations either directly, by stimulating synthesis of extracellular matrix components and reducing
collagenase
production, or indirectly through other profibrogenic factors such as connective tissue growth factor (CTGF).
TGF-beta
is important for the proliferation of intrarenal fibroblasts and the epithelial-mesenchymal transition through which tubular cells become fibroblasts. Although several factors induce
TGF-beta
expression in the kidney, one very interesting aspect is the link between the renin-angiotensin-aldosterone (Aldo) system (RAAS) and
TGF-beta
. Angiotensin II (ANG II) stimulates
TGF-beta
expression in the kidney by various mechanisms and upregulates receptors for
TGF-beta
. ANG II can directly phosphorylate Smads without inducing
TGF-beta
. Recent data provide compelling evidence that other components of the RAAS including ANG III, renin, and Aldo also activate the
TGF-beta
system. As direct modulation of the
TGF-beta
system is not yet feasible in humans, angiotensin-converting enzyme (ACE) inhibitors and angiotensin type 1 (AT1)-receptor blockers are currently the most potential drugs to interfere with this ANG II-mediated
TGF-beta
expression. This review highlights some current aspects of the interaction between the RAAS and the
TGF-beta
axis.
...
PMID:Renal injury due to renin-angiotensin-aldosterone system activation of the transforming growth factor-beta pathway. 1698 15
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