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Results for “Collagen Type V”

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At least 19 recordsLinked to original sources
PubMed1979

The covalent structure of calf skin type III collagen. V. The amino acid sequence of the cyanogen bromide peptide alpha 1(III)CB9A (position 789 to 927).

The cyanogen bromide peptide alpha 1(III)CB9A is 139 amino acid residues in length and occupies positions 789--927 along the alpha 1(III) chain. Peptides necessary for the complete sequence analysis were obtained after fragmentation of alpha 1(III)CB9B with trypsin, protease from Staphylococcus aureus V8, hydroxylamine and chymotrypsin. They were separated mainly by chromatography on Sephadex G-50 and phosphocellulose and subsequently sequenced using the automated Edman degradation procedure.

Amino Acid Sequence↗
PubMed1979

Preferential digestion of basement membrane collagen by an enzyme derived from a metastatic murine tumor.

The specificity of human skin collagenase and of an enzyme from an invasive tumor were studied by using types I, II, III, IV, and V (AB) collagen as substrates. Human skin collagenase degraded types I, II, and III collagen, producing the characteristic 3/4 and 1/4 cleavage products, but failed to degrade type IV or V collagen. Collagenase prepared from the invasive tumors showed maximal activity after trypsin treatment. The tumor enzyme degraded type IV (basement membrane) collagen, producing fragments consistent with a single cleavage site but did not attack types I, II, III, and V collagen. Because type IV collagen prepared by pepsinization of placenta was also digested, it is likely that cleavage of type IV collagen by the tumor collagenase occurs within a largely helical domain. A type IV collagenase could play a significant role in tumor metastases and in normal tissues where basement membrane turnover takes place.

Animals↗
PubMed2025

COL5A1 in the tumor microenvironment predicts the prognosis of head and neck cancer.

ObjectivesThis study aims to investigate the significance of tumor microenvironment (TME)-related genes and signal transduction pathways in head and neck cancer (HNC).MethodsGene expression and clinical data of HNC patients were obtained from the Cancer Genome Atlas (TCGA) database. Differentially expressed genes (DEGs) were screened through a multi-step filtration approach to obtain candidate predictors. The biological role of COL5A1 in HNC was verified through rigorous bioinformatic analysis, experimental validation using quantitative real-time PCR (qRT-PCR), immunohistochemical (IHC) analysis from HNC samples, and IHC data from the Human Protein Atlas (HPA) database.ResultsCOL5A1 was significantly upregulated in HNC tissues and cell lines. High COL5A1 expression was significantly associated with advanced tumor grade (P&#x2009;<&#x2009;.05) and shorter survival (TCGA: P&#x2009;<&#x2009;.001; GSE42743: P&#x2009;=&#x2009;.004). COL5A1 was an independent prognostic indicator (univariate analysis: HR&#x2009;=&#x2009;1.324, P&#x2009;=&#x2009;.001; Multivariate analysis: HR&#x2009;=&#x2009;1.326, P&#x2009;=&#x2009;.005). It was enriched in pathways related to tumor invasion and immune responses, and its expression was associated with decreased levels of CD8+ T cells and increased levels of macrophages and neutrophils. Spatial distribution analysis revealed higher expression at the tumor's leading edge (vs. tumor core: P&#x2009;<&#x2009;.001). COL5A1 expression is associated with tumor stage, with more pronounced expression in advanced-stage tumors.ConclusionCOL5A1 represented a novel potential prognostic indicator and therapeutic target in an HNC database sample, as its expression is closely linked to tumor progression, immune cell infiltration, and adverse clinical outcomes. These findings, primarily derived from squamous cell carcinoma-dominated cohorts, warrant further functional validation.

Humans↗
PubMed1979

Platelet-reactivity of isolated constituents of the blood vessel wall.

Collagens I and III, in fibrillar form, bound platelets equally well; both readily induced platelet aggregation. In contrast, collagens IV and V, although pretreated as collagens I and III to induce fibrillogenesis, failed to produce aggregation. No binding of platelets was detected. Lens capsule, containing collagen type IV in situ, was also inactive. Inactivity appears due to the lack of an appropriate quaternary structure since segment-long-spacing (SLS) aggregates of collagens IV and V, as of type I, induced aggregation. Elastin and its associated microfibrillar element did not aggregate platelets; some binding of platelets to elastin only was observed.

Animals↗
PubMed1976

Defects in the biochemistry of collagen in diseases of connective tissue.

The collagens are the major structural glycoproteins of connective tissues. A unique primary structure and a multiplicity of post-translational modification reactions are required for normal fibrillogenesis. The post-translational modifications include hydroxylation of prolyl and lysyl residues, glycosylation, folding of the molecule into triple-helical conformation, proteolytic conversion of precursor procollagen to collagen, and oxidative deamination of certain lysyl and hydroxylysyl residues. Any defect in the normal mechanisms responsible for the synthesis and secretion of collagen molecules or the deposition of these molecules into extracellular fibers could result in abnormal fibrillogenesis; such defects could result in a connective tissue disease. Recently, defects in the regulation of the types of collagen synthesized and in the enzymes involved in the post-translational modifications have been found in heritable diseases of connective tissue. Thus far, the primary heritable disorders of collagen metabolism in man include lysyl hydroxylase deficiency in Ehlers-Danlos syndrome type VI, p-collagen peptidase deficency in Ehlers-Danlos syndrome type VII, decreased synthesis of type III collagen in Ehlers-Danlos syndrome type IV, lysyl oxidase deficency in S-linked cutis laxa and Ehlers-Danlos syndrome type V, and decreased synthesis of type I collagen in osteogenesis imperfecta.

Aortic Diseases↗
PubMed1976

Interaction between proteoglycan subunit and type II collagen from bovine nasal cartilage, and the preferential binding of proteoglycan subunit to type I collagen.

We studied the interaction of proteoglycan subunit with both types I and II collagen. All three molecular species were isolated from the ox. Type II collagen, prepared from papain-digested bovine nasal cartilage, was characterized by gel electrophoresis, amino acid analysis and CM-cellulose chromatography. By comparison of type I collagen, prepared from papain-digested calf skin, with native calf skin acid-soluble tropocollagen, we concluded that the papain treatment left the collagen molecules intact. Interactions were carried out at 4 degrees C in 0.06 M-sodium acetate, pH 4.8, and the results were studied by two slightly different methods involving CM-cellulose chromatography and polyacrylamide-gel electrophoresis. It was demonstrated that proteoglycan subunit, from bovine nasal cartilage, bound to cartilage collagen. Competitive-interaction experiments showed that, in the presence of equal amounts of calf skin acid-soluble tropocollagen (type I) and bovine nasal cartilage collagen (type II), proteoglycan subunit bound preferentially to the type I collagen. We suggest from these results that, although not measured under physiological conditions, it is unlikely that the binding in vivo between type II collagen and proteoglycan is appreciably stronger than that between type I collagen and proteoglycan.

Amino Acids↗
PubMed1975

Gel electrophoretic studies on proteoglycans and collagen of abnormal human growth cartilage: proteoglycan abnormalities in pseudoachondroplasia and in Kniest's disease.

The microchemical study of growth cartilage biopsies may improve the classification and the genetic advice of some types of growth disturbances and contribute to the understanding of biochemical defects. Small tibial growth cartilage biopsies were performed during orthopedic surgery in cases with achondroplasia, pseudoachondroplasis (three cases), Kniest's disease (two cases), diastrophic dwarfism (two cases), parastrematic dwarfism, pycnodysos tosis, mucolipidosis type III, Blount's disease, and in three normal growing children. Five human fetal cartilages were also studied. The proteoglycans were extracted with 4 M guanidinium chloride. After dialysis against 8 M urea at pH 7, the proteoglycans were obtained by ion chromatography in urea on DEAE-cellulose and submitted to gel electrophoresis on polyacrylamide-agarose gels. The gel electrophoresis of the proteoglycans of growth cartilage of normal growing children gave two metachromatic bands situated close one to another. The proteoglycans extracted from fetal growth cartilage gave a single band with a slightly slower migration. An abnormal gel electrophoretic pattern was found in pseudoachondroplasia and in Kniest's disease. In pseudoachondroplasia a single wide band was found; in overcharged tubes several thin, more rapid bands appeared in addition to the main band. In Kniest's disease three bands were found. In all of the other syndromes studied two normally or almost normally situated bands were present. Small differences in the width and intensity of the bands observed in several cases were difficult to assess. In all cases except mucolipidosis III and Kniest's disease the collagen was extracted by using limited cleavage and solubilization with pepsin, purified and analyzed by polyacrylamide gel electrophoresis. A type of collagen with a single alpha band was found.

Achondroplasia↗
PubMed1978

Action of 5-bromodeoxyuridine on tooth germs "in vitro". II. - Effects on collagen synthesis.

The first lower molar tooth germs removed from 16-day-old mouse embryos were cultured for 2 days on a standard medium and then for 24 hours on the same medium containing BrdU (treated tooth germs) or not (controls). We attempted to study the effects of 5-Bromodeoxyuridine on the type I and type III collagen synthesis 24 (stage 16 + 4) and 72 (stage 16 + 6) hours after the incorporation of this thymidine analogue. At stage 16 + 4, type I and type III collagen were synthesized both in control and BrdU-treated tooth germs. However BrdU induced quantitative modifications in the type I collagen synthesis which might be explained by modifications in the turnover of this type of collagen. At stage 16 + 6, the BrdU treatment resulted in the inhibition of the terminal differentiation of odontoblasts. Consequently, the normal amplification of collagen type I synthesis could not occur. However, both control and BrdU-treated tooth germs synthesized type I and type III collagen. Quantitatively, the synthesis of type III collagen was slightly affected by BrdU treatment.

Animals↗
PubMed1976

Action of human hyperlipemic sera on the biosynthesis of intercellular matrix macromolecules in aorta organ cultures.

Explants from rabbit aortic media were incubated in MEM medium supplemented with 14C-lysine and with 10 p. 100 hyperlipemic (type IV and V) or normal human serum respectively. The incubated fragments were extracted at increasing ionic strength. The insoluble collagen and elastin were hydrolysed with collagenase and alcoholic potassium hydroxyde respectively. The radioactivity was determined in the extracts and the radioactive labelling profile of proteins was investigated on polyacrylamide gel electrophoresis in SDS. With the exception of the collagenase extract (polymeric collagen) the incorporation of the radioactivity into insoluble collagen is not altered or increases. These the incubation was carried out in the presence of hyperlipemic serum. Incorporation of the radioactivity into insoluble collagen seems not to be altered. These results show a decreased protein synthesis with a relative increase in the biosynthesis of polymeric insoluble collagen in the aortic media incubated in the presence of hyperlipemic serum.

Adult↗
PubMed1978

[Ultrastructural organization of the basic substance of human dermis].

The data on ultrastructural organization of the ground substance in the human dermis obtained electron histochemically are represented. Five types of ruthenium positive structures of polysaccharide origin are detected: retinal structure (I), amorfous substance (II), membranes of collagen fibrils (III) and elastic fibres (V), fine ruthenium positive streakness of collagen fibrils (IV). These structures, except fine streakness, form a united polysaccharide system of the dermis participating in maintenance of structural-functional integrity of the connective tissue (collagen-elastic) carcass of the dermis. Two mechanisms, interconnected and oppositely directed, perform this function: the buffer mechanism preventing the connective tissue fibers and collagen fibrils to approach each other, and the binding mechanism preventing the fibrils and fibers to dissociate. The reticular structure performs mainly this function at the level of fibers, and the amorphous substance does it at the level of fibrils.

Collagen↗