Gene/Protein Disease Symptom Drug Enzyme Compound
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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)

Purkinje cells from false tendons of young rabbits, pigs and fetal lambs were dispersed by the action of collagenase and elastase and grown in culture for up to 14 days. Immunofluorescent staining with fluorescein-labelled antibodies to cardiac myosin and tropomyosin demonstrated cross-banding and/or a diffuse positive stain in Purkinje cells between 3 and 7 days in culture. Electron microscopy of cultured Purkinje cells at 3 days and 7 days revealed some disorganization of the myofilament system, in particular loss of Z-band material, as well as many thickened Z-bands, 120 nm to 240 nm in width. Gap junctions remained but desmosomes and fasciae adherentes were fewer in number. Organelles such as ribosomes, glycogen and mitochondria did not alter. Some Purkinje cells were spontaneously contractile in culture for up to seven days. Dominguez and Fozzard [7] propose that buckling of the Purkinje fibre and the production of sarcolemmal folds on the cell surface affect conduction of electrical impulses. We suggest that Purkinje cell contraction may play a major part in producing these geometric changes affecting conduction.
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PMID:Cardiac Purkinje cells in culture. 668 23

During the past decade, strains of Bacteroides fragilis that produce an enterotoxin have been implicated in diarrheal disease in animals and humans. The extracellular enterotoxin has been purified and characterized as a single polypeptide (M(r), approximately 20,000). Single specific primer-PCR was used to clone a portion of the B. fragilis enterotoxin gene. The recombinant protein expressed by the cloned gene fragment reacted with monospecific antibodies to B. fragilis enterotoxin by enzyme-linked immunosorbent assay and immunoblot analysis. The deduced amino acid sequence revealed a signature zinc-binding consensus motif (HEXXHXXGXXH/Met-turn) characteristic of metalloproteases termed metzincins. Sequence comparisons showed close identity to matrix metalloproteases (e.g., human fibroblast collagenase) within the zinc-binding and Met-turn region. Purified enterotoxin contained 1 g-atom of Zn2+ per molecule and hydrolyzed gelatin, azocoll, actin, tropomyosin, and fibrinogen. The enterotoxin also underwent autodigestion. The N-terminal amino acid sequences of two autodigestion products were identical to the deduced amino acid sequence of the recombinant enterotoxin and revealed cleavage at Cys-Leu and Ser-Leu peptide bonds. Gelatinase (type IV collagenase) activity comigrated with the toxin when analyzed by gel fractionation and zymography, indicating that protease activity is due to the enterotoxin and not to a contaminating protease(s). Optimal proteolytic activity occurred at 37 degrees C and pH 6.5. Primary proteolytic cleavage sites in actin were identified, revealing cleavage at Gly-Met and Thr-Leu peptide bonds. Enzymatic activity was inhibited by metal chelators but not by inhibitors of other classes of proteases. Additionally, cytotoxic activity of the enterotoxin on human carcinoma HT-29 cells was inhibited by acetoxymethyl ester EDTA. The metalloprotease activity of the enterotoxin suggests a possible mechanism for enterotoxicity and may have additional implications in the study of disease caused by B. fragilis.
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PMID:The enterotoxin of Bacteroides fragilis is a metalloprotease. 780 55

We have identified, by differential cDNA library screening, 15 serum inducible genes in the human diploid fibroblast cell line WI-38. The genes fall into two classes that are distinguished by their dependence on protein synthesis for the induction by serum, i.e., primary and secondary genes. While 11 of these genes encode known proteins, 4 other genes have not been described to date. The former genes encode proteins of diverse functions, including the monocyte-derived neutrophil chemotactic factor (MONAP), calmodulin, tropomyosin, tenascin, collagenase, plasminogen activator inhibitor-2a, the 'sperm-specific' cleavage signal-1 protein, metallothionein IIa and the mitochondrial chaperonin hsp-60. Interestingly, one of the unknown genes contains a large open reading frame for a polypeptide that is highly homologous to a previously unidentified long open reading frame in the opposite strand of the gene coding for the transcription factor HTF-4. We also studied the regulation of these serum-induced genes during cell cycle progression in normally cycling WI-38 and HL-60 cells separated by counterflow elutriation as well as in serum-stimulated HL-60 cells. Our results clearly show that, in contrast to the prevailing opinion, the expression of most genes induced after mitogen stimulation is not subject to a significant regulation in normally proliferating cells. This supports the hypothesis that the progression into S from either G0 or G1 are distinct processes with specific patterns of gene expression.
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PMID:Identification of serum-inducible genes: different patterns of gene regulation during G0-->S and G1-->S progression. 800 57

Single smooth muscle cells isolated from guinea pig ileum using collagenase and papain produce contractile response to muscarinic agents, while the cultured cells do not. Using fluo-3/AM and a confocal laser scanning fluorescence microscope, it was observed that carbachol, a muscarinic agent, caused an increase in the intracellular Ca2+ of both single and cultured cells. SDS-PAGE and Western Blot analyses revealed the expression of myosin heavy chain isoforms of SM1 (204 kDa) and SM2 (200 kDa) in single smooth muscle cells, and non muscle isoform (196 kDa) of myosin heavy chain only in the cultured cells. With respect to actin isoforms, alpha-actin was predominant in single cells and beta-actin was major in the cultured cells. Two types of tropomyosin monomer, 39 kDa and 41 kDa, were detected in single cells, while the 41 kDa monomer was lost in cultured cells. These differences in contractile protein profiles between single and cultured cells were collaborated with the observation of cells using immunofluorescence microscope with responsible antibodies to isoforms of myosin heavy chain, actin and tropomyosin. These results suggest that the loss of contractility in cultured smooth muscle cells is profoundly related to changes in contractile protein profiles from smooth muscle type to non muscle type.
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PMID:Contractile protein isoforms of single and cultured smooth muscle cells from guinea pig ileum. 1037 28

Single smooth muscle cells (SMCs) isolated from guinea pig ileum using collagenase and papain were cultured on laminin-coated dishes in MEM containing fetal calf serum. Temporal changes in intracellular calcium ion concentration in response to carbachol and to ATP were investigated using fluo-3/AM and fluorescence microscopy. It was observed that carbachol caused an increased intracellular calcium ion in freshly isolated single SMCs but a reduced or negative response of cultured SMCs before confluence. On the other hand, ATP was observed to cause an increase in the calcium ion content of SMCs throughout the culture. SDS-PAGE and Western blot analyses revealed changes in the expression of contractile proteins as follows. l-Caldesmon and non-muscle type myosin heavy chain (NMHC) (considered to be marker molecules for dedifferentiation in smooth muscle cells) and non-muscle type tropomyosin were not observed in freshly isolated single SMCs. l-Caldesmon and NMHC appeared in the cultured SMCs within 2 days and the tropomyosin isoform was observed 6 days following seeding. Simultaneously, smooth muscle type myosin heavy chain (SMHC) decreased strikingly and the 41 kDa tropomyosin monomer was lost. The content of alpha-actin decreased gradually to a minimum on day 6 when non-muscle type tropomyosin appeared, and the cells began to proliferate rapidly. These results suggest that the loss of contractility in cultured smooth muscle cells is more closely related to changes in contractile protein profiles than to receptor-mediated signal transduction and that in addition to NMHC and l-caldesmon, non-muscle type tropomyosin may be useful as a marker molecule for de-differentiation of smooth muscle cells.
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PMID:Changes in Ca2+ signaling and contractile protein isoforms in smooth muscle cells from guinea pig ileum during culture. 1159 84

Several genes are regulated by tocopherols which can be categorized, based on their function, into five groups: genes that are involved in the uptake and degradation of tocopherols (Group 1) include alpha-tocopherol transfer protein (alpha-TTP) and cytochrome P450 (CYP3A); genes that are associated with lipid uptake and atherosclerosis (Group 2) include CD36, SR-BI and SR-AI/II. Genes that modulate the expression of extracellular proteins (Group 3) include tropomyosin, collagen(alpha1), MMP-1, MMP-19 and connective tissue growth factor (CTGF). Genes that are related to inflammation, cell adhesion and platelet aggregation (Group 4) include E-selectin, ICAM-1, integrins, glycoprotein IIb, II-2, IL-4 and IL-beta. Group 5 comprises genes coding for proteins involved in cell signaling and cell cycle regulation and consists of PPAR-gamma, cyclin D1, cyclin E, Bcl2-L1, p27 and CD95 (Apo-1/Fas ligand). The expression of P27, Bcl2, alpha-TTP, CYP3A, tropomyosin, II-2, PPAR-gamma, and CTGF appears to be up-regulated by one or more tocopherols whereas all other listed genes are down-regulated. Several mechanisms may underlie tocopherol-dependent gene regulation. In some cases protein kinase C has been implicated due to its deactivation by alpha-tocopherol and its participation in the regulation of a number of transcription factors (NF-kappaB, AP-1). In other cases a direct involvement of PXR/RXR has been documented. The antioxidant responsive element (ARE) appears in some cases to be involved as well as the transforming growth factor beta responsive element (TGF-beta-RE). This heterogeneity of mediators of tocopherol action suggests the need of a common element that could be a receptor or a co-receptor, able to interact with tocopherol and with transcription factors directed toward specific regions of promoter sequences of sensitive genes. Here we review recent results of the search for molecular mechanisms underpinning the central signaling mechanism.
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PMID:Regulation of gene expression by alpha-tocopherol. 1531 6

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.
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PMID:Vitamin E mediates cell signaling and regulation of gene expression. 1575 36