Characterization of procollagen synthesized by matrix-free cells isolated from chick embryo tendons

Biochemistry ◽  
1976 ◽  
Vol 15 (22) ◽  
pp. 4935-4942 ◽  
Author(s):  
Jouni Uitto ◽  
Jack R. Lichtenstein ◽  
Eugene A. Bauer
Keyword(s):  
Chick Embryo ◽  
Free Cells ◽  
Matrix Free

scholarly journals Underhydroxylated minor cartilage collagen precursors cannot form stable triple helices

1988 ◽  
Vol 250 (1) ◽  
pp. 65-70 ◽  
Author(s):  
C C Clark ◽  
C F Richards
Keyword(s):  
Chick Embryo ◽  
Triple Helix ◽  
Iron Chelator ◽  
Prolyl Hydroxylase ◽  
Type Ii ◽  
Native Structure ◽  
Lysyl Hydroxylase ◽  
Free Cells ◽  
Triple Helices ◽  
Matrix Free

Matrix-free cells from chick-embryo sterna were incubated with various concentrations of 2,2′-bipyridyl, an iron chelator that inhibits prolyl hydroxylase and lysyl hydroxylase. At concentrations in the region of 0.1 mM, significant effects on cartilage collagen hydroxylation and secretion were observed. When the underhydroxylated collagens were subsequently digested with chymotrypsin or chymotrypsin plus trypsin at 4 degrees C for 15 min, the minor cartilage collagen precursors (namely types IX and XI) were extensively degraded; type II procollagen was only partially susceptible and was converted into underhydroxylated collagen. The results demonstrate that there were significant differences in triple-helix stability among cartilage collagens such that the underhydroxylated minor collagen precursors were unable to attain a native structure under conditions where type II procollagen was successful.

vitreal cells and specialized phagocytes in the chick embryo retina: A TEM and SEM study

1990 ◽  
Vol 48 (3) ◽  
pp. 330-331
Author(s):  
M.A. Cuadros ◽  
M.J. Martinez-Guerrero ◽  
A. Rios
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Acid Phosphatase ◽  
Chick Embryo ◽  
Basement Membrane ◽  
Sem Images ◽  
Intimate Contact ◽  
Cellular Processes ◽  
Sem Study ◽  
Free Cells

In the chick embryo retina (days 3-4 of incubation), coinciding with an increase in cell death, specialized phagocytes characterized by intense acid phosphatase activity have been described. In these preparations, all free cells in the vitreal humor (vitreal cells) were strongly labeled. Conventional TEM and SEM techniques were used to characterize them and attempt to determine their relationship with retinal phagocytes.Two types of vitreal cells were distinguished. The first are located at some distance from the basement membrane of the neuroepithelium, and are rounded, with numerous vacuoles and thin cytoplasmic prolongations. Images of exo- and or endocytosis were frequent; the cells showed a well-developed Golgi apparatus (Fig. 1) In SEM images, the cells was covered with short cellular processes (Fig. 3). Cells lying parallel to or alongside the basement membrane are elongated. The plasma membrane is frequently in intimate contact with the basement membrane. These cells have generally a large cytoplasmic expansion (Fig. 5).

Cartilage associated protein (CASP) is a novel developmentally regulated chick embryo protein

1997 ◽  
Vol 110 (12) ◽  
pp. 1351-1359
Author(s):  
P. Castagnola ◽  
M. Gennari ◽  
R. Morello ◽  
L. Tonachini ◽  
O. Marin ◽  
...  
Keyword(s):  
Chick Embryo ◽  
Developmentally Regulated ◽  
Reading Frame ◽  
Amino Terminal ◽  
Nuclear Antigens ◽  
Cartilage Extracellular Matrix ◽  
Low Levels ◽  
Specific Rabbit ◽  
Chicken Protein

A subtracted cDNA library was generated to identify cDNAs specific for chondrocyte mRNAs preferentially expressed at the hypertrophic stage with respect to early differentiation stages. The characterization of a cDNA isolated from this library that hybridizes with a 1.8 kb mRNA is described here. This mRNA is expressed at extremely low levels in dedifferentiated chondrocytes cultured in adherent conditions, at very low levels in differentiating chondrocytes and at very high levels in hypertrophic chondrocytes cultured in suspension conditions. In the developing chick embryo this mRNA is detectable in RNAs extracted from several other tissues besides cartilage. The described cDNA contains a complete open reading frame coding for a polypeptide of about 33 kDa. Homology searches with known cDNA and protein sequences have revealed that the chicken protein is related to the amino-terminal half of two mammalian nuclear antigens. By immunohistochemistry with specific rabbit antisera a strong signal was detected in the cartilage extracellular matrix of selected regions of the developing skeleton. Because of this localization of the antigen we named this protein cartilage associated protein (hereafter referred to as CASP).

scholarly journals Post-translational alterations in newly synthesized cartilage proteoglycans induced by the glutamine analogue 6-diazo-5-oxo-l-norleucine. Time course of inhibition and recovery

1991 ◽  
Vol 273 (2) ◽  
pp. 283-288 ◽  
Author(s):  
C C Clark ◽  
C F Richards ◽  
R V Iozzo
Keyword(s):  
Time Course ◽  
Chondroitin Sulphate ◽  
Time Dependent ◽  
Dependent Manner ◽  
Cartilage Proteoglycan ◽  
Chondroitin Sulphate Proteoglycan ◽  
Cartilage Proteoglycans ◽  
Matrix Free ◽  
Subsequent Addition

Incorporation of [35S]sulphate by cultures of matrix-free cells from chick embryo sterna in the presence of the glutamine analogue 6-diazo-5-oxo-L-norleucine (0.58 mM) was inhibited in a time-dependent manner to less than 15% of that in control cultures after 2 h. Characterization of the major cartilage proteoglycan synthesized under these conditions showed that it contained few, if any, normal-sized chondroitin sulphate chains and only about half of the normal complement of substituted serine residues. Subsequent addition of D-glucosamine hydrochloride (final concn. 2 mM) resulted in a time-dependent recovery of [35S]sulphate incorporation to 90% of control cultures after 2 h, but restored the chondroitin sulphate chains to normal size within 15 min. On the basis of these results, it is concluded that a 2 h preincubation is necessary to deplete the chondrocytes of the endogenous supply of UDP-N-acetyl-D-glucosamine required for optimal glycoconjugate synthesis, and that this situation results in the synthesis of a chondroitin sulphate proteoglycan with significantly altered properties, owing to the paucity of glycosaminoglycan chains; however, this condition is completely reversible if the D-glucosamine pool is repleted.

scholarly journals Characterization of phospholipids accumulated in pulmonary-surfactant compartments of rats intratracheally exposed to silica

1989 ◽  
Vol 262 (3) ◽  
pp. 781-786 ◽  
Author(s):  
H Adachi ◽  
H Hayashi ◽  
H Sato ◽  
K Dempo ◽  
T Akino
Keyword(s):  
Molecular Species ◽  
Pulmonary Surfactant ◽  
Lamellar Bodies ◽  
Compositional Change ◽  
Substrate Specificities ◽  
Free Cells ◽  
Acidic Phospholipids ◽  
Silica Treatment ◽  
Intratracheal Injection

Phospholipids in the lung fractions, i.e. alveolar free cells, extracellular pulmonary surfactant, intracellular pulmonary surfactant (lamellar bodies) and microsomal fractions, of rats were examined 28 days after intratracheal injection of silica (40 mg/kg). Significant accumulations of phospholipids were observed in the extracellular- and intracellular-surfactant fractions of rats exposed to silica. The prominent phospholipid accumulated was phosphatidylcholine (PC), consisting mainly of the dipalmitoyl species. However, a compositional change in acidic phospholipids of surfactant fractions was produced by the silica treatment. The percentage of phosphatidylglycerol (PG) was significantly decreased; in contrast, that of phosphatidylinositol (PI) was increased. Thus the ratio PG/PI in the surfactant fractions was markedly decreased in response to silica. This compositional change in both acidic phospholipids occurred even in the early stages, i.e. before appreciable accumulations of alveolar phospholipids were noticed. The molecular-species profiles of both acidic phospholipids in the surfactant fractions were distinctly different from each other. The dipalmitoyl species accounted for more than 30% of PG and less than 6% of PI, respectively. These species patterns of PG and PI were similar in control and silica-treated rats. These findings suggest two possibilities that (1) PG and PI destined for pulmonary surfactant are synthesized from each specific CDP-diacylglycerol (DG) pool having different molecular species in the lung, or (2) individual enzymes responsible for synthesis of surfactant PG and PI have substrate specificities for molecular species of CDP-DG, thereby producing PG and PI having different molecular species in surfactant compartments.

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