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J S Perlish

Publications and source records attributed to J S Perlish.

At least 37 records · Page 2Linked to original sources
PubMed1988

Procollagen intermediates during tendon fibrillogenesis.

The purpose of this study was to correlate ultrastructural features of tendon collagen fibrils at various stages of development with the presence of procollagen, pN-collagen, pC-collagen, and the free amino propeptides and carboxyl propeptide of type I procollagen. Tendons from 10-, 14-, and 18-day chicken embryos reveal small, well-defined intercellular compartments containing collagen fibrils with diameters showing a unimodal distribution. At 21 days (hatching) and 9 days (post hatching) and at 5 weeks (post hatching), the compartments are larger, less well-defined, and there is multimodal distribution of tendon fibril diameters. Procollagen and the intermediates pN-collagen and pC-collagen are present in tendons up to 18 days. Thereafter there is a marked reduction in procollagen, whereas the intermediates persist throughout all stages of development. Similarly, free amino propeptides and carboxyl propeptides of type I procollagen were found at all stages. The amino propeptide of type III procollagen was restricted to the peritendineum until 7 weeks post hatching. At that time, a network of fibrils containing the amino propeptide of type III procollagen was seen delineating well-circumscribed compartments of collagen fibrils throughout the entire tendon. This study supports the notion that pN- and pC-collagen have an extracellular role and participate in collagen fibrillogenesis.

Animals↗
PubMed1987

Amino and carboxyl propeptides in bone collagen fibrils during embryogenesis.

Collagen fibrillogenesis was studied in tibiae of chick embryos, 9, 11, and 14 days old. Specimens were incubated with antibodies against the amino and the carboxyl propeptides of type-I collagen and subjected to ferritin-labelling immuno-electron microscopy. The amino propeptide was found in thin fibrils, 20-40 nm in diameter, distributed at 60-nm periodicity. The carboxyl propeptide antibody labelled a wide spectrum of fibrils, although the majority were in the range of 40-100 nm, distinctly larger than those labelled with the amino propeptide antibody. The presence of pN (amino propeptide plus collagen) and pC (carboxyl propeptide plus collagen) collagen was also demonstrated by Western blotting in all specimens. This study suggests that the sequence of propeptide removal may regulate collagen fibril diameter.

Animals↗
PubMed1987

The carboxylpropeptide of type I procollagen in skin fibrillogenesis.

Previous studies suggested that the aminopropeptide of type I procollagen may initiate fibril formation. The purpose of this investigation was to study the location of the carboxylpropeptide of type I procollagen during collagen fibrillogenesis. Chick embryonic and posthatching skin specimens were studied by immunofluorescence and immunoelectron microscopy and by immunoblotting with antibodies against the amino and carboxylpropeptide of type I procollagen. The carboxylpropeptide was demonstrated at the surface of collagen fibrils, 20-40 nm in diameter (10-day embryos) and in fibrils, 40-65 nm (21-day embryos). In addition, the carboxylpropeptide was found at the cell surface and free in the ground substance. The aminopropeptide was only seen in fibrils, 20-30 nm in diameter, as previously reported. Ratios of pN-collagen/pC-collagen increased from 16 days embryonic to 3 and 9 days postembryonic skins. This study suggests that both pN-collagen (aminopropeptide plus collagen) and pC-collagen (carboxylpropeptide plus collagen) participate in fibrillogenesis.

Animals↗
PubMed1985

Collagen synthesis regulation by the aminopropeptide of procollagen I in normal and scleroderma fibroblasts.

The effect of the aminopropeptide of type I procollagen, Col 1(I), on collagen synthesis by normal and scleroderma fibroblasts was investigated. Collagen synthesis was inhibited by about 42% when normal fibroblasts were labeled with 3H-proline in the presence of 4 microM Col 1(I). In contrast, collagen synthesis by scleroderma fibroblasts was inhibited to a lesser degree, about 19%. Furthermore, scleroderma fibroblasts with elevated rates of collagen synthesis (2.5-5 times normal) were inhibited by only about 10%. The data suggest that the increased accumulation of collagen in the skin of scleroderma patients may be related to a defect in the regulation of collagen synthesis by the aminopropeptide.

Adult↗
PubMed1985

Collagen synthesis in scleroderma: selection of fibroblast populations during subcultures.

In progressive systemic scleroderma, excessive deposition of collagen leads to fibrosis of several tissues including the skin. It has been found that different populations of fibroblasts are present in scleroderma skin; these can be obtained by establishing cell cultures from different layers of the involved skin. Excessive overproduction of collagen was noted in primary cultures of cells obtained from deeper layers of the skin of patients in an early stage of the disease, whereas control fibroblasts did not manifest significant variations dependent on the layers of skin used to initiate the cultures. The synthesis of type-I and -III collagen was found to be altered concomitantly. The production of collagen and collagenous proteins was then followed during subcultivations of overproducing fibroblasts. In many cell strains, increased synthesis of collagen and/or non-collagenous proteins had already been lost after the first subcultivation, whereas overproduction was stable in others. However, after five passages, most of the cultures showed normal collagen synthesis, which probably indicates a loss of phenotype due to successive subcultures or overgrowth by another population of fibroblasts.

Adult↗
PubMed1984

Lymphokine/monokine inhibition of fibroblast proliferation and collagen production: role in progressive systemic sclerosis (PSS).

A normal fibrotic response to inflammatory stimuli appears to be dependent on the balanced production of a number of stimulatory and inhibitory fibroblast-regulatory mediators by activated mononuclear cells (MNL). To investigate whether altered mediator production contributes to the fibrosis observed in progressive systemic sclerosis (PSS), we stimulated human peripheral blood MNL with concanavalin A (Con A) and lipopolysaccharide (LPS) to produce macromolecular mediators that inhibit the proliferation and the collagen production of cultured normal human fibroblasts. The two Con A-induced mediators were lymphokines (LK) as they were exclusively produced by activated T cells and they coeluted from a Sephacryl S-200 column with a Mr of 50,000. In contrast, the two LPS-induced mediators were monokines (MK) as they were exclusively produced by activated monocytes, and they coeluted in the Mr 20,000 range. Each pair of inhibitory LK and MK may also be distinct as inhibition of collagen production still occurred in proliferatively quiescent cultures. A quantitative comparison of the levels of fibroblast-inhibitory LK/MK produced by normal volunteers and long-term PSS patients revealed that although PSS MNL produced normal levels of both collagen production inhibitory mediators, they were aberrant producers of both proliferation inhibitory mediators, being hypo-producers (-49%) of the LK and hyper-producers (+196%) of the MK. These results suggest that reduced production of proliferation inhibitory LK may allow stimulatory mediators to induce the unrestricted fibroblast proliferation observed in early active PSS, which then may be stabilized in long-term PSS by the increased production of proliferation inhibitory MK.

Adult↗
PubMed1983

Collagen synthesis in generalized morphea.

Synthesis of collagen and non-collagenous proteins was measured in fibroblast cultures derived from different layers of the dermis from a patient with an early stage of localized scleroderma. Increased synthesis of collagen was found in fibroblasts grown from the subcutaneous fat of this patient, whereas cells obtained from the papillary dermis revealed normal metabolism. These data agree with the results obtained in previous experiments with cells derived from patients with progressive systemic sclerosis in primary culture, thus indicating that the two diseases have a common pathomechanism. Several subcultures of the activated fibroblast populations were also studied. Normal collagen synthesis in these cultures was observed after the fifth passage, probably indicating selection of cell populations or loss of the previous phenotype.

Adipose Tissue↗
PubMed1983

Collagen fibril formation during embryogenesis.

Chicken embryo skin of different ages and adult skin were labeled with antibodies against the amino propeptide and carboxyl propeptide of type I collagen and processed for indirect immunoelectron microscopy by the ferritin technique. The results indicate that the formation of thin collagen fibrils involves polymerization of pN-collagen. Fibrils that are thicker than 35-40 nm do not appear to contain the amino propeptide. How fibrils increase in size is not clear, but growth may involve mechanisms such as lateral aggregation of subfibril structures or fusion of thin fibrils. Carboxyl propeptides were localized near or in contact with thin collagen fibrils, but they did not appear to be arranged in a periodic manner along the fibrils. In experiments using antibodies against the amino propeptides of type III collagen, fibrils 20-40 nm in diameter were also labeled in a periodic fashion. pN-Collagen chains were extracted from embryonic skin and identified by NaDodSO4/polyacrylamide gel electrophoresis and by immunoblotting. The presence of significant amounts of pN-collagen in skin from 10- and 12-day chicken embryos agreed well with the labeling of amino propeptides by immunoelectron microscopy. This study provides evidence for the role of the amino propeptide in collagen fibrillogenesis in embryonic skin.

Animals↗
PubMed1983

Increased procollagen mRNA levels in scleroderma skin fibroblasts.

Procollagen messenger RNA activity in scleroderma and normal skin fibroblasts was measured using a cell-free translation assay. Radioactive translation products were fractionated by electrophoresis and the ratio of procollagen to total incorporation was determined from densitometric scans of gel fluorograms. In 4 scleroderma cell lines 1.78% (+/- 0.10) of incorporated [35S]-methionine was in procollagen, compared to 1.00% (+/- 0.20) in 5 normal controls. These values are consistent with previously reported increases in the rates of collagen synthesis obtained with intact cells and show that most if not all of the increase can be explained on the basis of elevated translatable procollagen messenger RNA in scleroderma fibroblasts.

Adult↗
PubMed1981

Ultrastructural identification of extension aminopropeptides of type I and III collagens in human skin.

Human skin was labeled with purified antibodies against type II and III collagens and against their extension aminopropeptides by using the ferritin technique. Both aminopropeptides were visualized mainly along thin collagenous fibrils (diameter, 20-40 nm) and rarely in nonfibrillar regions of the skin. The labeling showed a periodicity of 60-65 nm resembling the D (67 nm) stagger of collagen molecules. Blocking of antibodies with aminopropeptides and treatment of tissues with procollagen NH2-terminal protease abolished labeling. Antibodies against type I collagen uniformly labeled approximately equal to 80% of the fibrils (diameter, 20-80 nm), while reaction with antibodies against type III collagen was restricted to thin fibrils. It is currently thought that the aminopropeptides of procollagen molecules are cleaved after they are released from the cell and before fibril formation. Our data indicate that aminopropeptides are removed at the fibrillar level and that fibril growth can be regulated by extracellular procollagen processing.

Amino Acid Sequence↗
PubMed1981

Variability in collagen and fibronectin synthesis by scleroderma fibroblasts in primary culture.

Primary cultures of fibroblasts obtained from the papillary, reticular and subcutaneous layer of scleroderma skin were analyzed for protein synthesis by metabolic labeling and radioimmunoassays. Several of these cultures showed a 10- to 20-fold increase in the production of total protein and collagen as well as of fibronectin and type III procollagen as compared to cells from unaffected individuals. Most of the increases were noted in the reticular and subcutaneous layers. With cells from other patients increased synthesis was found in some of the explants or for only some of the products. The heterogeneity observed here could represent heterogeneity in the disease, in the cells studied or in the state of the disease at the time the cells were obtained.

Adult↗
PubMed1980

Capillary alterations in scleroderma.

Electron microscopy of capillaries was performed in scleroderma skin. The main alterations were (1) gaps, vacuolization and eventual destruction of endothelial cells, (2) reduplication of the basal lamina, (3) perivascular cellular infiltrates consisting of lymphocytes, plasma cells, macrophages, or monocytes, and (4) fibroblasts and pericytes with enlarged, rough endoplasmic reticulum (RER) accompanied by perivascular fibrosis. Perivascular cellular infiltrates and endothelial cell damage appear to precede the stage of fibrosis.

Adult↗
PubMed1980

Immunoelectron microscopy of type III collagen in normal and scleroderma skin.

Normal and scleroderma skin was studied by indirect immuno-electron microscopy with specific antibodies against Type III collagen. Fine collagen fibrils, 200-400 A in diameter were labeled with antitype III collagen antibodies. These antibodies attached to the collagen fibril forming rings with a 650 A periodicity. Fibrils with more than 600 A in diameter were only labeled with antitype I collagen antibodies. Type III collagen was found around small blood vessels, adipocytes and smooth muscle cells, thus, corresponding to the distribution of reticulin.

Antibodies↗