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Biomedical subjects

E J Miller

Publications and source records attributed to E J Miller.

At least 127 records · Page 7Linked to original sources
PubMed1980

Isolation of a unique collagenous fraction from limited pepsin digests of human placental tissue. Characterization of one of the constituent polypeptide chains.

Fractionation of the highly soluble collagens released during limited pepsin digestion of whole human placenta has resulted in the isolation of a unique collagenous fraction comprised exclusively of high molecular weight aggregates. On reduction and alkylation, the aggregates dissociated yielding collagen-like polypeptides with an apparent Mr = 40,000 as well as a heterogeneous mixture of much smaller noncollagenous peptides. Ion exchange chromatography of the collagen-like, 40,000-dalton subunits results in recovery of a single relatively acidic component and a mixture of at least two relatively basic components. Both the basic and acidic components contain large amounts of cysteine, hydroxylysine glycosides, and glucosamine, and exhibit compositional features indicative of the presence of collagenous and noncollagenous domains. These unusual features have been verified for the more acidic component through isolation of its major cyanogen bromide cleavage products. Characterization of the cyanogen bromide fragments further indicated that this particular subunit is characterized by alternating collagenous and noncollagenous domains as opposed to a lengthy collagenous domain which is either preceded or followed by noncollagenous sequences. The molecular organization and possible derivation of these unique pepsin-resistant collagenous components is discussed.

Amino Acids↗
PubMed1980

Collagen types synthesized in dermal fibroblast cultures from patients with early progressive systemic sclerosis.

Fibroblast cultures were established by explant culture from upper and lower dermis of 7 normal donors and 10 patients with early progressive systemic sclerosis (PSS). Antibodies against collagens containing the A and B chains, collagens which occur largely in vascular structures, were isolated and used for immunofluorescence studies. Cultures from lower PSS dermis accumulated significantly more of these collagens than fibroblast cultures from upper PSS dermis or cultures from upper or lower dermis of normal skin. These data indicate that the collagens containing the A and B chains in early PSS lesions are produced by cells of vascular origin and support the concept that alterations in vascular tissue play a prominent role in the pathogenesis of PSS.

Adult↗
PubMed1980

Chinese hamster lung cells synthesize and confine to the cellular domain a collagen composed solely of B chains.

The acid-soluble collagen extracted from cultured Chinese hamster lung (CHL) cell layers has been isolated after limited pepsin digestion and differential salt fractionation. Polyacrylamide gel electrophoresis of this material under denaturing conditions showed the presence of collagen chains with an apparent molecular mass of 120,000 daltons both before and after reduction, indicating the absence of interchain disulfide bonds in the native molecule. When chromatographed on CM-cellulose under denaturing conditions, the majority (> 90%) of the CHL cell layer collagen chains eluted as relatively basic components slightly before the human alpha 2(I) chain and coincident with the human B chain. In addition, the CM-cellulose elution profiles of the cyanogen bromide peptides derived from the human B chain and from the CHL cell layer chain were essentially identical. Examination of CHL cells in culture by using affinity-purified antibody to human B chain revealed this collagen to be localized in an extracellular matrix surrounding the cells. Furthermore, analysis of the culture medium indicated the absence of any comparable collagen chain. These data provide additional evidence for the existence of a molecular form of collagen composed solely of B chains and suggest that this molecular form of collagen has an unusual affinity for the cell layer in this system.

Animals↗
PubMed1980

Autoantibodies to basement membrane collagen: epidermolysis bullosa simplex versus bullous pemphigoid.

As judged by passive hemagglutination and hemagglutination-inhibition assays, sera from six patients in one family with dominant epidermolysis bullosa contain clearly demonstrable titers of antibodies against the collagen C chain which is derived from basement membrane structures. Moreover, the circulating antibodies observed in these patients are apparently specific for the C chain as no titers were observed when using four additional well-characterized collagen chains in the indicated assays. In contrast to the results with sera from epidermolysis bullosa patients, sera from a series of age- and sex-matched healthy controls, as well as from a group of patients with bullous pemphigoid, did not contain antibodies to any of the test antigens. These results thus clearly differentiate the autoimmune response to basement membranes observed in bullous pemphigoid from that observed in epidermolysis bullosa simplex.

Autoantibodies↗
PubMed1980

Immunohistochemical localization of Type III collagen in the dentin of patients with osteogenesis imperfecta and hereditary opalescent dentin.

The immunohistochemical localization of Type III collagen was studied in the dentin from nine patients with dominantly inherited osteogenesis imperfecta (O.I.) and six patients with hereditary opalescent dentin (H.O.D.). The most consistent localization of Type III collagen was found in patients with O.I. Among these patients an indirect relationship existed between the severity of dentinal involvement and the presence of Type III antibody localization. Although a similar but less intense staining could be observed in some cases of H.O.D., the severity of dentinal alterations in H.O.D. was not correlative to the quantitative presence of material reacting with antibodies to Type III collagen. These observations further indicate that O.I. is not only clinically, but biochemically, a heterogeneous condition.

Adolescent↗
PubMed1979

The isolation and characterization of the cyanogen bromide peptides from the B chain of human collagen.

Cleavage of the collagen B chain with cyanogen bromide yields nine peptides which have been isolated and characterized with regard to molecular weight and amino acid composition. The peptides are recovered in equimolar quantities and account for the full amino acid complement of the chain as isolated following limited pepsin digestion of human placental tissue. These data thus confirm the unique composition of the chain and further indicate that the chain has been isolated in essentially pure form. The total number of amino acid residues (1018) observed in the cyanogen bromide peptides of the B chain indicate that it is comparable in length to the previously characterized collagen alpha chains. Thus, the apparent larger size of the B chain noted in previous studies may possibly be attributed to the relatively large quantities of hydroxylysine-linked carbohydrate, but more likely to the increased numbers of large hydrophobic amino acids in the B chain. Although the cyanogen bromide peptide pattern obtained in studies on the B chain serves to differentiate this chain from other known chains, some possible homologies between the B chain peptides and peptides derived from the alpha chains of type I, II, and III collagens are noted.

Amino Acids↗
PubMed1979

Immunohistochemical demonstration of basement membrane collagen in normal human skin and in psoriasis.

Antibodies prepared against the collagen C-chain derived from human placenta specifically strain the epidermal basement membrane of normal human skin as well as the basement membrane surrounding the skin appendages and capillaries. Using the antibodies, it was observed that all basement membranes in untreated psoriatic plaques appear fragmented and separted into several layers. The results suggest that psoriatic lesions are associated with a general loss of basement membrane integrity which may play a crucial role in the pathogenesis of the disease.

Antibody Specificity↗
PubMed1978

Affinity of fibronectin to collagens of different genetic types and to fibrinogen.

Fibronectin, a fibroblast surface protein, was purified from human and chicken plasma and extracts of cultured chicken fibroblasts with affinity chromatography on gelatin coupled to Sepharose particles. A fibronectin-like protein was also isolated from the plasma of Torpedo fish. The collagen binding properties of fibronectin were studied with several genetically distinct collagens. Heat denatured types I, II, and III collagens were equal in their binding capacity and more active than the native collagens or A and B chains. Native type III collagen was more active than the other native collagens. Human and chicken fibronectins showed approximately the same pattern of specificity. Identical specificities were shown by the plasma and fibroblast forms of chicken fibronectin. Two cyanogen bromide peptides of the collagen alpha1 (II) chain, CB8 and CB12, derived from different parts of the chain, were active in fibronectin binding. A polymer of the tripeptide pro-gly-pro, and polyproline were inactive. Fibronectin also binds to fibrinogen and fibrin. Comparison of this binding to collagen binding showed that fibrinogen inhibited binding of fibronectin to collagen, but was less active than native collagen. Two other fibrous proteins, tropoelastin and keratin, did not bind fibronectin. The binding of fibronectin to fibrinogen was inhibited by collagen and incorporation of fibronectin into blood clot in the cold was inhibited by gelatin. These results suggest that the binding of fibronectin to collagen and fibrinogen depends on the same binding site in the fibronectin molecule. It is proposed that cell surface fibronectin mediates attachment of cells to the collagenous extracellular matrix and to a temporary fibrin matrix in a wound.

Animals↗
PubMed1978

Characterization of the collagen chains synthesized by cultured smooth muscle cells derived from rhesus monkey thoracic aorta.

Five different collagen chains and one smaller collagenous fragment have been isolated from the collagens found in the combined cell layer and medium of rhesus monkey aortic smooth muscle cell cultures. The collagen chains which can be identified are alpha1 (III), alpha1(I), alpha2, A and B. The smaller collagenous peptide exhibits an apparent molecular weight of 45 000 and has been designated CP45 (Mayne, R., et al. (1977), Arch. Biochem. Biophys. 181, 462). Smooth muscle cells continue to synthesize the collagens from which these components are derived for at least eight passages in culture. At each passage the alpha1 (III) chain consistently represents about one-half of the total collagen which is recovered after initial fractionation by agarose gel chromatography. The results show that smooth muscle cells derived from rhesus monkey thoracic aorta are phenotypically stable for many generations in vitro.

Animals↗
PubMed1978

Scleroderma.

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Adult↗