Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Procollagen”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed1998

An RNA oligonucleotide corresponding to the polypyrimidine region of the rat alpha 1(I) procollagen promoter forms a stable triplex and inhibits transcription.

In this report we demonstrate formation of a triplex structure by an antiparallel RNA oligonucleotide corresponding to the 21 bp polypurine-pyrimidine stretch from -141 to -162 of the rat alpha 1(I) procollagen promoter with a Kd of 0.1-0.2 microM. The formation of triplexes by the triplex forming oligoribonucleotide (ORN) was also observed under physiological conditions. In vitro transcription run-off experiments showed that triplex formation results in inhibited transcription from the rat alpha 1(I) procollagen gene. Our results demonstrate a novel approach for down-regulation of procollagen gene transcription in vivo.

Animals↗
PubMed1988

Type I procollagen in the severe non-lethal form of osteogenesis imperfecta. Defective pro-alpha 1(I) chains in a patient with abnormal proteoglycan metabolism and mineral deposits in the dermis.

We have screened type I procollagen synthesized in vitro by skin fibroblasts from several patients with the severe non-lethal form of osteogenesis imperfecta. Cells from one patient synthesized and secreted both normal and a larger amount of abnormal type I procollagen. The abnormal alpha chains are larger in size due to post-translational overmodifications involving the whole triple helical domain. Abnormal collagen heterotrimers had a melting temperature 2.5 degrees-3 degrees C lower than normal ones or from controls. Chemical analysis of collagen in the medium showed a greater degree of both lysyl hydroxylation and hydroxylysyl glycosylation, the major increase in molecular mass of overmodified alpha chains being due to the higher hydroxylysine-bound hexose content. The proband's cells modify proteoglycan metabolism and mineral crystals form in the dermis, possibly a response to abnormal collagen-proteoglycan interactions. These findings can be explained by a small defect in the product of one allele for pro-alpha 1(I) chains: three-quarters of the synthesized type I procollagen molecules are composed of trimers containing one or two chains defective near the C-terminus of the triple helix or in the C-propeptide. The data obtained for this patient confirmed that the severity of clinical manifestations in osteogenesis imperfecta strongly depends on the location and nature of the mutations, and that the phenotype could be a consequence of a collagen defect(s) and its influence on collagen-collagen interactions and collagen interactions with other connective tissue components.

Cells, Cultured↗
PubMed1986

Ultrastructural localization of the major proteoglycan and type II procollagen in organelles and extracellular matrix of cultured chondroblasts.

The mechanisms of synthesis and intracellular routing of the various cartilage matrix macromolecules are still unclear. We have studied this problem in cultured chondroblasts at the ultrastructural level using monospecific antibodies against the core protein of the keratan sulfate/chondroitin sulfate-rich cartilage proteoglycan (KS:CS-PG) or Type II procollagen, and cuprolinic blue, a cationic dye that binds to the glycosaminoglycan chains of proteoglycans. Intracellularly, the proteoglycan antibodies localized KS:CS-PG and its precursors primarily in the Golgi complex and secretory vesicles. In contrast, the bulk of Type II procollagen was found within the rough endoplasmic reticulum (ER). While devoid of collagen, the extracellular matrix was rich in KS:CS-PG molecules some of which studded the chondroblast plasmalemma. Cuprolinic blue staining indicated that the proteoglycans present in the Golgi complex fell into a predominant class of large proteoglycans, probably representing KS:CS-PG, and a minor class of smaller proteoglycans. Groups of these divergent proteoglycans often occupied distinct Golgi subcompartments; moreover, single large proteoglycans appeared to align along the luminal surface of Golgi cisternae and secretory vesicles. These results suggest that in cultured chondroblasts KS:CS-PG and Type II procollagen are differentially distributed both in organelles and in the extracellular matrix, and that different proteoglycan types may occupy distinct subcompartments in trans Golgi.

Animals↗
PubMed1986

Immunolocalization of type III collagen and procollagen in cirrhotic human liver using monoclonal antibodies.

Immunolocalization of type III collagen and procollagen in cirrhotic human liver was studied using monoclonal antibody specific for the helical determinant of type III collagen extracted from human placenta. Deparaffinized, trypsin-treated cirrhotic liver sections from 8 autopsy cases were examined by the unlabeled peroxidase-antiperoxidase and immunofluorescence techniques. These techniques revealed the localization of this epitope shared by type III collagen and procollagen not only in the extracellular matrix of hepatocytes and sinusoidal cells but also in the cytoplasm. In hepatocellular carcinoma concurrent with cirrhosis, neoplastic cells were shown to react with this antibody as well. These results are consistent with data obtained using antiserum specific for bovine type III procollagen aminopeptide which appeared in our previous report.

Aged↗
PubMed1987

The extracellular matrix in oral Kaposi sarcoma (AIDS): the immunohistochemical distribution of collagens type IV, V, VI, of procollagens type I and III, of laminin and of undulin.

Twelve oral AIDS-associated Kaposi sarcomas (KS) were studied for the distribution of extracellular matrix components using indirect immunofluorescence. Staining for basement membrane (BM) components revealed two distinct patterns of distribution: a delicate and partly fragmented lining of BMs around sinusoid-like vascular spaces or an occasional diffuse interstitial fluorescence in the tumour stroma; or an irregular broad rim of fluorescence in walls of larger blood vessels. These findings support a vascular cell origin of the endothelial- and spindle cell component in KS. The tumour stroma was almost completely negative for collagen type V and undulin, whereas an intensive fluorescence was noted for procollagens type I, III and collagen type VI. In areas adjacent to KS a loss of procollagens type I and III, collagens type V, VI and undulin was noted. An intimal sheath of collagen type V was usually absent from blood vessels of the tumour or the peritumourous connective tissue. Immunohistochemical findings indicate that the preexisting interstitial connective tissue matrix is destroyed during tumour invasion and that subsequently procollagens type I, III and collagen type VI are synthesized de novo by cells of the tumour stroma.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Effect of polyethylene on osteocalcin, alkaline phosphatase and procollagen secretion by human osteoblastic cells.

We have studied the direct effects of polyethylene particles on osteoblastic function in primary human bone cell cultures. The cells were obtained from trabecular bone fragments of patients undergoing knee reconstructive surgery. When the cells reached confluency, they were subcultured into two flasks, one untreated (control culture) and the other treated with polyethylene particles, and incubated until confluency. Osteoblastic function was evaluated by assaying osteocalcin, alkaline phosphatase, and C-terminal procollagen type I, with and without 1,25(OH)2D stimulation, in the cell-conditioned medium. We found that addition of polyethylene to these osteoblastic cell cultures induced higher levels of secreted osteocalcin after 1, 25(OH)2D stimulation. Alkaline phosphatase levels increased whereas C-terminal procollagen type I levels decreased in the cell conditioned medium after polyethylene was added to the cultures. Treatment of the control cultures with 1,25(OH)2D stimulated alkaline phosphatase levels and decreased C-terminal procollagen type I. However, these osteoblastic markers in 1,25(OH)2D-treated cells did not change in cultures with polyethylene. This study demonstrates that polyethylene particles have a direct effect on osteoblastic markers in human bone cells in culture.

Aged↗
PubMed1985

Bleomycin selectively elevates mRNA levels for procollagen and fibronectin following acute lung injury.

We employed the technique of dot blot hydridization of radiolabeled cDNA probes to examine the role of specific mRNA content in the control of extracellular matrix turnover in the remodeling rat lung. Following bleomycin instillation, total RNA content gradually doubled during the first 5 days following the initial lung injury, then rose much more rapidly during the ensuing 9 days. Individual mRNAs for procollagens I and III and for fibronectin were selectively enriched 2- to 4-fold above total RNA during the first week after bleomycin instillation. No comparable increases were observed in specific RNAs from liver, indicating that the response observed in the lung was not generalized to other organs. Moreover, the increases in mRNA species for procollagen types I or III in the lung could not be related to the influx of inflammatory cells which migrate into the lungs during acute injury, as cells obtained by alveolar lavage contained no mRNAs for procollagens.

Animals↗
PubMed1987

Presence of different types of procollagen messenger RNAs in human hepatoma cell lines.

Human hepatoma cell lines were shown for the first time to contain various types of procollagen mRNAs. The amounts and types of procollagen mRNAs differed depending on the cell lines. Pro alpha 1 (III) and pro alpha 1 (IV) collagen mRNAs were present in PLC/PRF/5, a hepatocellular carcinoma cell line, whereas pro alpha 1 (I), pro alpha 2 (I), pro alpha 1 (IV) and pro alpha 2 (V) collagen genes contrast, HepG2 cells derived from hepatoblastoma contained little, if any, mRNAs for these types of procollagens we had examined.

Actins↗
PubMed1987

Serum concentration of N-terminal procollagen peptide of collagen type III in schistosomal liver fibrosis.

The major cause of mortality in human schistosomiasis is the chronic granulomatous reaction of the liver tissue to Schistosoma mansoni eggs. Liver biopsy still provides the best evaluation of the degree of liver damage. However, liver biopsy does not provide an image of the dynamic process of fibrogenesis. Variations of concentrations of procollagen type III peptide in sera have been proposed to be significant markers of liver fibrosis. Thus, liver function tests in relation to histopathological diagnosis and procollagen type III peptide concentrations were studied in patients with schistosomiasis and revealed a high correlation between the serum procollagen type III peptide and the degree of fibrosis in liver tissue.

Adult↗
PubMed1985

Coated vesicles purified from chick tendon fibroblasts contain newly synthesized type I procollagen.

Coated vesicles were purified from embryonic chick tendon fibroblasts pulsed with [3H]proline. They were morphologically and biochemically similar to coated vesicles purified from other sources. Furthermore, they contained newly synthesized Type I procollagen which was protected from bacterial collagenase digestion unless detergent was present. The procollagen remained associated with coated vesicles during immune precipitation and agarose gel electrophoresis. Data from pulse-chase experiments demonstrated that the specific activity of the coated vesicle preparations was approx. 5-fold higher at the 10 min chase point than at either the 0 or 40 min chase points. These data are consistent with the hypothesis that coated vesicles are intermediates in the intracellular transport of newly synthesized Type I procollagen in chick tendon fibroblasts.

Animals↗
PubMed1987

Disulfide bonding as a determinant of the molecular composition of types I, II and III procollagen.

Procollagen molecules have amino-terminal and carboxy-terminal propeptides at the respective ends of the collagenous triple helix. The carboxy-terminal propeptides enhance and direct the association of pro alpha-chains into procollagen molecules, but the mechanism of this registration function is still obscure. A hypothesis concerning the function of disulfide bonding in the assembly of types I, II and III procollagen is put forward here.

Isomerases↗
PubMed1976

Preparation and use in immunohistology of antibodies specific for type I and type III collagen and procollagen.

Antibodies to bovine type I and type III collagen and their precursor form procollagen were produced in rabbits and rendered specific for the immunizing antigen by immunoadsorption. These purified antibodies showed distinct immunofluorescence staining on frozen sections of both bovine and human connective tissue at concentrations as low as 1-10 mug/ml. Antibodies to type III collagen and procollagen reacted with reticulin in liver and spleen, with fascicles around tendons and with the upper portion of the dermis. Antibodies to type I collagen and procollagen reacted with skin and fiber bundles in tendon but did not stain reticulin. No reaction was observed with cartilage collagen or with kidney glomerular basement membrane.

Animals↗
PubMed1987

Surface-induced aggregation of type I procollagen.

We have examined the state of aggregation of type I procollagen in the concentration range 5 to 800 micrograms/ml. Electron microscopy typically indicates a high proportion of aggregated material (greater than 50%), when a range of preparative techniques are used. Aggregates of in-register molecules (segment-long-spacing-like aggregates) are frequently observed, often with units of in-register molecules connected via the C-terminal propeptides. In contrast, studies using gel-filtration chromatography and density-gradient ultracentrifugation demonstrate only limited aggregation in solution (less than 5%) even at 800 micrograms/ml. The aggregated material is mainly dimeric and probably not segment-long-spacing-like. We conclude that aggregation of procollagen is strongly favoured by adsorption to a surface when samples are prepared for electron microscopy. The possible relevance of these observations to the fate of procollagen secreted by cells in vivo is discussed.

Animals↗
PubMed1985

Generalized inhibition of cell-free translation by the amino-terminal propeptide of chick type I procollagen.

Fragments of the amino-terminal propeptide of procollagen have been shown to inhibit the synthesis of procollagen in cultured cells and in a reticulocyte lysate cell-free system (for review see Timpl, R. and Glanville, R.W. (1981) Clin. Orth. Rel. Res. 158, 224-242). In this report, we show that the full-length amino-terminal propeptide of chick pro alpha1(I) chains inhibits the translation of chick tendon mRNA and rat brain mRNA in a reticulocyte lysate cell-free system. The synthesis of procollagen and non-collagenous proteins was equally affected. Inhibition was dose-dependent up to 10 microM. A similar pattern of inhibition was observed for the collagenase-resistant fragment, col 1(I).

Animals↗
PubMed1982

Reiteration frequency of procollagen genes in the guinea pig genome. Collagen genes are not amplified during granuloma fibroblasts differentiation.

Procollagen mRNA was purified from collagen synthesizing polysomes obtained from an experimental guinea pig granuloma, and iodinated in vitro. The procollagen 125I-labelled mRNA was hibridized with granuloma and liver guinea pig DNA in vast DNA excess conditions. A Cot 1/2 800-900 mol . s . 1-1 for both tissues was obtained from the hybridization curves. With these results, we could suggest the existence of 11-13 procollagen genes per haploid genome. By the analysis of the hybridization data it was possible to infer that there is no genomic amplification in tissues highly specialized in the synthesis of collagen such as granuloma.

Animals↗
PubMed1981

Thrombin affects fibronectin and procollagen in the pericellular matrix of cultured human fibroblasts.

We have studied the effects of human thrombin on the isolated pericellular matrix of cultured human lung fibroblasts. Cell-free matrices were prepared from confluent cultures of cells by extraction with sodium deoxycholate and hypotonic buffer after radiolabeling the cultures with [14C]glycine. After the extraction, only a few radiolabeled polypeptides were retained on the culture dishes. These were identified as fibronectin, procollagens, and as yet unidentified polypeptides with molecular weights of 180 000, 140 000, 66 000 and 43 000. The matrices were exposed to thrombin in serum-free medium and the changes in the matrix-associated proteins were studied in autoradiograms of polyacrylamide gels. As a result of the treatment, there was massive release of both fibronectin and procollagen from the matrices into the medium. In addition , thrombin cleaved the 66 000 dalton polypeptide to a 62 000 dalton form that remained in the matrix. Collagenase treatment did not bring about the release of fibronectin or affect the 66 000 dalton protein. Some procollagen was also cleaved by thrombin; when high concentrations of thrombin were used cleavage of fibronectin took place. These effects of thrombin may operate in wounded areas in vivo.

Cell-Free System↗
PubMed1986

Diabetes stimulates procollagen degradation in rat tendon in vitro.

To identify the mechanisms responsible for the paucity of recently synthesized collagen in connective tissues during diabetes, in vitro procollagen metabolism was studied in non-diabetic (control) and diabetic rats. Achilles tendons from the two groups were incubated for 1-8 h (35 degrees C) in medium containing [14C]proline and the radiolabeled collagen in the tissue, and that released into the media, were examined by SDS-polyacrylamide gel electrophoresis and fluorography. The bulk of the radiolabeled collagen in tendon from the diabetics was recovered as degradation products; these, but also procollagen and collagen components, were prominent in the control tissues. Moreover, the collagenous components synthesized by the diabetic rat tendons were more readily digested in vitro by trypsin than those produced by control tissues. We conclude that diabetes reduces collagen accretion in connective tissues in part due to increased intracellular degradation of procollagen.

Animals↗
PubMed2004

The relation between myocardial cyclic variation of integrated backscatter and serum concentrations of procollagen propeptides in hypertensive patients.

Cyclic variation of integrated backscatter (IBS), or CVIBS, provides a noninvasive method to measure myocardial collagen deposition and ischemia in hypertensive patients. We hypothesized that serum procollagen propeptides can offer additional values to CVIBS for evaluating cardiac changes related to fibrosis or ischemia. A total of 21 patients were enrolled in this study and were divided into three groups according to the presence of hypertension and serum carboxyterminal propeptide of type I procollagen (PICP) concentration; these were: 7 hypertensive patients with PICP > or = 127 microg/L (group 1), 7 hypertensive patients with PICP < 127 microg/L (group 2), 7 normotensive subjects with PICP < 127 microg/L (group 3). In addition to PICP, serum aminoterminal propeptide of type III procollagen (PIIINP), stress 201thalium scintigraphy and CVIBS were examined. Phase-compensated amplitudes of CVIBS at mid posterior and mid anteroseptal segments were significantly lower in group 1 (p < 0.05). Patients with fixed 201thallium perfusion defects had lower phase-compensated amplitudes of CVIBS at mid anteroseptal segment and higher PIIINP concentrations (p < 0.05). In conclusions, decrease of myocardial phase-compensated amplitude accompanied with increase of serum PICP concentration may be indicative of the underlying fibrotic process of hypertensive myocardium. Decrease of this CVIBS parameter with increase of serum PIIINP implies concomitant myocardial ischemia.

Biomarkers↗