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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cells from the cysts of patients with autosomal dominant polycystic kidney disease (PKD) were grown in vitro under standard conditions without the aid of collagen-pretreated surfaces, and both the synthesis and composition of the extracellular matrix were investigated. At confluence, PKD cells presented the typical features of epithelial cells, but showed a different collagen composition from fibroblasts. Compared with normal tubular epithelia (NTE), PKD monolayers produced an excess of extracellular matrix, which accounted for 30% of the total incorporation of [3H] proline, although this value was considerably lower (by a factor of 10) in the case of NTE. Immunohistochemical and electrophoretic techniques revealed a complex collagen composition in the extracellular matrix which included [alpha (III)]3 and collagen IV. However, part of the collagen components remained unidentified in spite of the fact that they exhibited a typical M(r) of alpha 1(I) and alpha 2(I) in the presence of urea. Immunoprecipitation with monospecific antibodies and Northern blotting with specific probes failed to recognize alpha 1(I) and alpha 2(I), but demonstrated their presence in fibroblasts. Purification and cyanogen bromide digestion demonstrated a strong interhomology in fingerprint peptide composition among the uncharacterized collagens synthesized by PKD cells, thus suggesting a common identity. These observations document a markedly augmented production of extracellular matrix by PKD cultured cells in vitro, and show the presence of collagens which do not share homologies with the major collagen molecules. A better characterization of extracellular matrix composition is central to any comprehension of the cytogenetic mechanisms in vivo.
Virchows Arch B Cell Pathol Incl Mol Pathol 1992
PMID:Extracellular matrix formation by epithelial cells from human polycystic kidney cysts in culture. 136 16

Pulmonary fibrosis is a well-known toxic response to bleomycin treatment. Here we demonstrate the direct effects of bleomycin on lung fibroblasts that resulted in a marked increase of collagen synthesis as compared with total noncollagen protein synthesis. Bleomycin treatment of rat lung fibroblast cultures resulted in an increase of total cellular transforming growth factor-beta (TGF-beta) mRNA and increased secretion of TGF-beta protein into the conditioned media. beta 2-Microglobulin was measured as an mRNA that did not increase with bleomycin treatment. The bleomycin-induced increase of TGF-beta mRNA was decreased by cells cultured in the presence of either cycloheximide, an inhibitor of protein synthesis, or 2-mercapto-1-(beta-4-pyridethyl) benzimidazole, an inhibitor of RNA synthesis. To assess the mechanism underlying increased steady-state mRNA levels, the nuclear fraction was isolated from bleomycin-treated cells and the TGF-beta transcripts were determined. Transcription of TGF-beta mRNA was increased 12 h after bleomycin treatment, whereas the transcription of type I procollagen, type III procollagen, and beta-actin mRNAs were increased after 48 h of bleomycin treatment. beta 2-Microglobulin mRNA synthesis was not increased within this time frame. These results suggest bleomycin regulation of TGF-beta at both the mRNA and protein levels. Rats lung fibroblasts were separated by cell sorting into two subpopulations. One population of fibroblasts demonstrated increased procollagen type I mRNAs, whereas fibroblasts in the other population had increased procollagen type III mRNA. Following bleomycin treatment, TGF-beta mRNA was shown to be located more prominently in those fibroblasts that contain primarily collagen type I mRNAs.
Am J Respir Cell Mol Biol 1992 Feb
PMID:Bleomycin regulation of transforming growth factor-beta mRNA in rat lung fibroblasts. 137 88

Two monoclonal antibodies, designated 1F8 (IgG1) and 5B10 (IgG1), have been produced in mice against native human type III collagen. These antibodies were highly type and species specific, recognizing the triple helical domain of type III as tested by ELISA. Immunofluorescence studies using each of these antibodies resulted in a fibrous staining pattern in human skin dermis. Immunogold electron microscopy resulted in a periodic distribution of gold particulates along banded collagen fibrils. Assuming that the total contour length of pepsin digested type III collagen is 300 nm, measurements of antibody-antigen complexes visualized by rotary shadowing revealed that each antibody bound at the same two sites: one approximately at the middle of the helix (153 nm from the N-terminus), the other at a site one-quarter the triple helical length from the N-terminus (75 nm). That the one-quarter binding site was closest to the N-terminus was determined by antibody incubation following tadpole collagenase treatment, which results in a larger, N-terminus containing fragment (binding antibody) and a smaller C-terminus containing fragment (not binding antibody). Located at each antibody binding epitope is a sequence of 10 amino acids: Gly-Ala-Hyp-Gly-Leu-Arg-Gly-Gly-Ala-Gly. Renatured cyanogen bromide-cleaved(CB)-peptides, CB4 and CB8, containing these repeated sequences reacted with each antibody, whereas other renatured type III CB-peptides were unreactive as determined by Western blotting analysis and ELISA. This was further confirmed by inhibition tests using a 10 residue synthetic peptide of identical sequence, which yielded 20-30% inhibition of antibody binding to native type III collagen at 4 degrees C. However, no inhibition was noted at higher temperature. These results indicate that both monoclonal antibodies recognize a specific helical conformation of 10 or slightly fewer residues in the three identical polypeptide chains comprising type III collagen.
Mol Immunol 1992 Jun
PMID:Repeated helical epitopes of defined amino acid sequence in human type III collagen identified by monoclonal antibodies. 137 14

RHP was purified from normal serum by sequential euglobin precipitation, ion exchange chromatography on DEAE-Sephacel and gel filtration using Sephacryl S-300. RHP reacted with anti-Factor H antibodies in ELISA assays and in Western blots, suggesting that it is antigenically related to Factor H. It bound to intact C1q but not to the collagen-like N-terminal half of the molecule. C1q-specific monoclonal antibody BUS-1, which blocks the binding of C1q to immune complexes, did not block the binding of RHP to C1q. This implies that the binding sites on C1q for IgG and RHP do not overlap.
Mol Immunol 1992 Oct
PMID:RHP is antigenically related to factor H and binds to the globular heads of C1q. 138 44

Changes in the temporal and spatial patterns of expression of mRNA encoding uterine extracellular matrix (ECM) proteins were determined during the peri-implantation period. Northern blot hybridization of cDNAs corresponding to laminin (LM) B1, LM B2, entactin, fibronectin, collagen (CL) type IV alpha 1, and CL IV alpha 2 was performed on RNA extracted from either whole mouse uteri or endometrial explants between Day 4, i.e., the day of implantation, and Day 7 of pregnancy, when the decidual response is well established. These analyses revealed a dramatic increase in LM B2, CL IV alpha 1, and CL IV alpha 2 mRNA expression by Day 7 of pregnancy. Relative levels of the mRNA encoding other ECM components, including LM B1, were not altered when compared to changes in the relative level of expression of glyceraldehyde-3-phosphate dehydrogenase mRNA. The differential expression of the B chains of LM appeared to be limited to the stromal cells of the endometrium. In situ hybridization of uterine sections with cRNA probes corresponding to LM B1, LM B2, and CL IV alpha 1 demonstrated that LM B1 was expressed temporally in high amounts in the primary decidual zones (PDZ) and persisted throughout PDZ degeneration. LM B2 mRNA was expressed in both primary and secondary decidual zones and persisted through Day 8 of pregnancy. CL IV alpha 1 mRNA expression mimicked that of LM B2. Oviduct ligation on Day 2 of pregnancy was used to prevent embryo transport to one uterine horn, whereas decidualization and embryo implantation were permitted in the contralateral horn. This experiment demonstrated that the increases in uterine ECM mRNA expression were not due solely to the changing hormonal milieu of the uterus. ECM components, including CL IV, have been shown to bind growth factors such as transforming growth factor-beta (TGF-beta) in an insoluble but biologically active form. The remarkable similarity between the pattern of CL IV and LM B2 expression and previously reported TGF-beta deposition (Tamada et al., Mol Endocrinol 1990; 4:965-972) prompted examination of the effects of this growth factor on blastocyst development in vitro. TGF-beta 1 was tested for its ability to alter embryo outgrowth on LM-coated tissue culture surfaces; however, significant differences in the rate or extent of outgrowth in the presence of TGF-beta were not detected.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential temporal and spatial expression of mRNA encoding extracellular matrix components in decidua during the peri-implantation period. 139 7

Fetal skin fibroblasts produce a soluble "migration stimulating factor" (MSF) which is not made by their normal adult counterparts. MSF stimulates the migration of adult skin fibroblasts into 3D collagen gels, thus providing the basis of a convenient bioassay for its presence. We have previously reported that MSF stimulates hyaluronic acid (HA) synthesis by adult skin fibroblasts and that this effect on matrix deposition appears to be responsible for the observed increase in cell motility. In the present study, wound fluid samples were collected from 18 patients undergoing surgery for various nonmalignant conditions and these were then fractionated according to the protocol used to isolate MSF from fetal fibroblast-conditioned medium. Detectable levels of migration stimulating activity were present in 17/18 (94%) of these samples. Paired serum samples obtained both pre- and postoperatively from five patients with positive wound fluid samples were also analyzed for MSF activity; such activity was found in only 1/5 (20%) of the preoperative and 0/5 (0%) of the postoperative serum samples. These data suggest that the MSF present in wound fluid is not derived from a plasma transudate or from platelet degranulation, but may reflect the transient and localized reinitiation of MSF production by adult fibroblasts in response to wounding. Taken together with previous observations regarding the effect of MSF on fibroblast migration and HA synthesis, our data suggest a possible physiological function of MSF in the wound healing response. Previous studies have revealed that MSF is produced by a subpopulation of apparently persistent fetal-like skin fibroblasts obtained from breast cancer patients and is also found in the serum of these individuals. Wound fluid and serum samples were accordingly collected from patients undergoing surgery for various types of malignant conditions or with a previous history of cancer; detectable levels of MSF activity were found in 8/10 (80%) of these wound fluid samples, 2/3 (66.6%) of the preoperative, and 3/3 (100%) of the postoperative paired serum samples. These findings suggest that the presence of detectable serum levels of MSF is not restricted to breast cancer and may be a general feature of malignant disease.
Exp Mol Pathol 1992 Aug
PMID:Detection of migration stimulating activity in wound fluid. 139 94

Collagen is the most important component of the extracellular matrix of the myocardium; it supports the myocytes and maintains the architecture of the heart. Collagen also participates in the myocardial response to various forms of pressure overload. Increased tissue collagen content occurs as a result of spontaneous or experimental overload-induced myocardial hypertrophy. In order to determine the mechanisms responsible for the increased collagen deposition in experimental cardiac hypertrophy, we established monolayer cultures of fibroblasts isolated from normal adult rat myocardium and studied their growth and biosynthetic characteristics. These cells have a doubling time of about 20h and synthesize and secrete several collagenous and non-collagenous proteins. We found that type I collagen was the major collagenous product of these cells representing 80% of total newly synthesized collagen. Most of the newly synthesized collagen was secreted into the culture medium as intact and partially cleaved procollagens. About 20% of the total collagen synthesized was type III collagen which was also secreted into the medium as a procollagen. A small proportion of type V collagen (less than 5%) was also synthesized by these cultures. Fibronectin which was identified by its mobility in SDS gel electrophoresis was quantified by immunoprecipitation with specific antisera and was the most abundant non-collagenous protein synthesized by these cells. Northern blot hybridization analysis demonstrated that these cells expressed transcripts for alpha 1 chains of types I and III collagen and for fibronectin.
J Mol Cell Cardiol 1992 Jul
PMID:Growth properties and biochemical characterization of collagens synthesized by adult rat heart fibroblasts in culture. 140 9

The present study examined the effect of cerium on collagen synthesis in cultured cardiac fibroblasts and explants. At 100 nM, a concentration comparable with that found in the cardiac tissue of patients with endomyocardial fibrosis, the element was found to enhance the incorporation of tritiated proline into collagen and non-collagen proteins while at 10 microM, it had an inhibitory effect. Cerium was found to have no effect on rates of DNA synthesis in fibroblasts at 100 nM. However, at this concentration, the element markedly enhanced the incorporation of tritiated uridine into RNA, suggesting that cerium may act at the level of transcription to stimulate collagen and non-collagen protein syntheses. The stimulatory action of very low levels of cerium on collagen synthesis may contribute to the accumulation of collagen seen in endomyocardial fibrosis.
J Mol Cell Cardiol 1992 Jul
PMID:Paradoxical effect of cerium on collagen synthesis in cardiac fibroblasts. 140 12

Although transformation of rodent fibroblasts can lead to dramatic changes in expression of extracellular matrix genes, the molecular basis and physiological significance of these changes remain poorly understood. In this study, we have investigated the mechanism(s) by which ras affects expression of the genes encoding type I collagen. Levels of both alpha 1(I) and alpha 2(I) collagen mRNAs were markedly reduced in Rat 1 fibroblasts overexpressing either the N-rasLys-61 or the Ha-rasVal-12 oncogene. In fibroblasts conditionally transformed with N-rasLys-61, alpha 1(I) transcript levels began to decline within 8 h of ras induction and reached 1 to 5% of control levels after 96 h. In contrast, overexpression of normal ras p21 had no effect on alpha 1(I) or alpha 2(I) mRNA levels. Nuclear run-on experiments demonstrated that the transcription rates of both the alpha 1(I) and alpha 2(I) genes were significantly reduced in ras-transformed cells compared with those in parental cells. In addition, the alpha 1(I) transcript was less stable in transformed cells. Chimeric plasmids containing up to 3.6 kb of alpha 1(I) 5'-flanking DNA and up to 2.3 kb of the 3'-flanking region were expressed at equivalent levels in both normal and ras-transformed fibroblasts. However, a cosmid clone containing the entire mouse alpha 1(I) gene, including 3.7 kb of 5'- and 4 kb of 3'-flanking DNA, was expressed at reduced levels in fibroblasts overexpressing oncogenic ras. We conclude that oncogenic ras regulates the type I collagen genes at both transcriptional and posttranscriptional levels and that this effect, at least for the alpha 1(I) gene, may be mediated by sequences located either within the body of the gene itself or in the distal 3'-flanking region.
Mol Cell Biol 1992 Oct
PMID:Regulation of collagen I gene expression by ras. 140 56

Platelet-activating factor (PAF) is a phospholipid with a wide spectrum of pro-inflammatory properties. In the lung, PAF induces airway hyperresponsiveness, neutrophil sequestration, and increased vascular permeability. The alveolar macrophage and the bronchial epithelium are tissues that are exposed to inhaled ozone (O3). We studied the effect of an in vitro O3 exposure on PAF production in a macrophage-like HL60 human cell line (dHL60), a human bronchial epithelial cell line (BEAS S6), and also in primary human bronchial epithelial cells. PAF was quantified by thin-layer chromatographic separation of lipid extracts from cells radiolabeled with [3H]lysoPAF and by radioimmunoassay. In vitro exposure of dHL60 cells to 0.05 to 1.0 ppm O3 for 15 to 120 min was found to significantly increase PAF levels above air control values at all exposure levels and time points (average increase of 92%). Similarly, BEAS S6 cells grown on collagen-coated filter supports and exposed to 0.05 to 1.0 ppm O3 for 60 min released an average increase in PAF of 626% above control values. Primary human bronchial epithelial cells also demonstrated significant increases in [3H]PAF release (average increase of 289% after exposure to 1.0 ppm O3 for 60 min) compared with paired air controls. These findings suggest that some of the effects of O3 inhalation may be mediated by PAF.
Am J Respir Cell Mol Biol 1992 Nov
PMID:Effect of ozone on platelet-activating factor production in phorbol-differentiated HL60 cells, a human bronchial epithelial cell line (BEAS S6), and primary human bronchial epithelial cells. 141 27


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