The ultrastructural organization of proteoglycans and collagen in human and rabbit scleral matrix

1985 ◽  
Vol 74 (1) ◽  
pp. 95-104
Author(s):  
R.D. Young
Keyword(s):  
Electron Microscopy ◽  
Articular Cartilage ◽  
Collagen Fibrils ◽  
Ultrastructural Organization ◽  
Connective Tissues ◽  
Collagen Organization ◽  
Band Position ◽  
Cuprolinic Blue ◽  
Relationship Of ◽  
Fibril Diameter

The distribution of proteoglycans and their association with collagen fibrils were studied in human and rabbit sclera following fixation of tissue in glutaraldehyde containing Cuprolinic Blue, a specific stain for proteoglycans when used in the presence of critical concentrations of electrolytes. Proteoglycans were visualized by electron microscopy as fine filaments, approximately 54 nm in length and 5 nm in diameter, associated with the d band in the gap zone of the periodic collagen banding pattern. Filaments were present in three orientations: (1) radiating from the d band to associate with corresponding sites on adjacent collagen fibrils; (2) encircling the collagen fibril at the d band position; and (3) lying along the fibril axis, often linking consecutive d bands. No difference was apparent between the proteoglycan-collagen organization in human and rabbit sclera. A similar arrangement of proteoglycan filaments in association with the d band was also evident throughout all levels of the sclera in spite of considerable variations in fibril diameter from inner to outer stroma. Furthermore, the specific relationship of proteoglycans with the collagen fibrils in sclera closely resembled that previously described in tendon and in articular cartilage, lending support to the view that the association of proteoglycans with collagen may be consistent in a majority of connective tissues, irrespective of their diverse functional specializations.

scholarly journals An immunoelectron microscope study of the organization of proteoglycan monomer, link protein, and collagen in the matrix of articular cartilage.

1982 ◽  
Vol 93 (3) ◽  
pp. 921-937 ◽  
Author(s):  
A R Poole ◽  
I Pidoux ◽  
A Reiner ◽  
L Rosenberg
Keyword(s):  
Electron Microscopy ◽  
Hyaluronic Acid ◽  
Articular Cartilage ◽  
Guanidine Hydrochloride ◽  
Collagen Fibrils ◽  
Ultrastructural Organization ◽  
Deep Zone ◽  
Superficial Zone ◽  
Bovine Articular Cartilage ◽  
Link Protein

Monospecific antibodies to bovine cartilage proteoglycan monomer (PG) and link protein (LP) have been used with immunoperoxidase electron microscopy to study the distribution and organization of these molecules in bovine articular cartilage. The following observations were made: (a) The interterritorial matrix of the deep zone contained discrete interfibrillar particulate staining for PG and LP. This particulate staining, which was linked by faint bands of staining (for PG) or filaments (for LP), was spaced at 75- to 80-nm intervals. On collagen fibrils PG was also detected as particulate staining spaced at regular intervals (72 nm), corresponding to the periodicity of collagen cross-banding. The interfibrillar PG staining was often linked to the fibrillar PG staining by the same bands or filaments. The latter were cleaved by a proteinase-free Streptomyces hyaluronidase with the removal of much of the interfibrillar lattice. Since this enzyme has a specificity for hyaluronic acid, the observations indicate that the lattice contains a backbone of hyaluronic acid (which appeared as banded or filamentous staining) to which is attached LP and PG, the latter collapsing when the tissue is fixed, reacted with antibodies, and prepared for electron microscopy. Thishyaluronic acid is anchored to collagen fibrils at regular intervals where PG is detected on collagen. PG and LP detected by antibody in the interterritorial zones are essentially fully extractible with 4 M guanidine hydrochloride. These observations indicated that interfibrillar PG and LP is aggregated with HA in this zone. (b) The remainder of the cartilage matrix had a completely different organization of PG and LP. There was no evidence of a similar latticework based on hyaluronic acid. Instead, smaller more closely packed particulate staining for PG was seen everywhere irregularly distributed over and close to collagen fibrils. LP was almost undetectable in the territorial matrix of the deep zone, as observed previously. In the middle and superficial zones, stronger semiparticulate staining for LP was distributed over collagen fibrils. (c) In the superficial zone, reaction product for PG was distributed evenly on collagen fibrils as diffuse staining and also irregularly as particulate staining. LP was observed as semiparticulate staining over collagen fibrils. The diffuse staining for PG remained after extraction with 4 M guanidine hydrochloride. (d) In pericellular matrix, most clearly identified in middle and deep zones, the nature and organization of reaction product for PG and LP were similar to those observed in the territorial matrix, except that LP and PG were more strongly stained and amorphous staining for both components was also observed. (e) This study demonstrates striking regional variations of ultrastructural organization of PG and LP in articular cartilage...

scholarly journals Submicroscopic structure of canine articular cartilage

2012 ◽  
Vol 49 (No. 6) ◽  
pp. 207-216 ◽  
Author(s):  
D. Horky ◽  
F. Tichy
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Articular Cartilage ◽  
Collagen Fibrils ◽  
Granular Endoplasmic Reticulum ◽  
Pericellular Matrix ◽  
Submicroscopic Structure ◽  
Intercellular Matrix ◽  
Cartilage Layer ◽  
Transport Vesicles

Canine articular cartilage was studied in male dogs at age 1, 4, 5 and 8 years. Samples collected from four hip joints and two humeral joints in each age category were processed by standard methods to be examined by scanning and transmission electron microscopy. The cartilage of both joints was similar in structure. In the superficial cartilage layer of one-year-old animals, individual spindle-shaped chondrocytes in the extracellular matrix were, together with associated collagen fibrils, located parallel to the surface. When viewed by scanning electron microscopy, they were distinctly prominent above the surrounding surface. Changes in the thickness and arrangement of both the chondrosynovial membrane and intercellular matrix were apparent in the 4-, 5- and 8-year-old animals, indicating the onset or progression of an osteoarthritic process. The middle cartilage layer in young animals showed elliptical chondrocytes occurring in pairs. The voluminous cytoplasm contained a great amount of granular endoplasmic reticulum, a large Golgi complex and numerous transport vesicles. The pericellular matrix, up to 1 µm thick, was composed of aperiodic fibrils. In the old animals the pericellular matrix was absent and was replaced by thick collagen fibrils with a marked periodicity. The deep cartilage layer in young dogs included groups of three to four chondrocytes situated in a common territory. The cytoplasm contained distinct bundles of intermediary filaments. The pericellular matrix occasionally formed septa between adjoining cells. The intracellular matrix included bundles of collagen fibrils arranged in a matted structure. In the old animals aggregation of chondrocytes into groups almost disappeared. The cytoplasm showed only short cisternae of granular endoplasmic reticulum, small numbers of mitochondria and transport vesicles, frequent lipid droplets and small glycogen deposits. The intercellular matrix consisted of only short collagen fibrils with no distinct periodicity.

scholarly journals Collagen Fibril Ultrastructure in Mice Lacking Discoidin Domain Receptor 1

2016 ◽  
Vol 22 (3) ◽  
pp. 599-611 ◽  
Author(s):  
Jeffrey R. Tonniges ◽  
Benjamin Albert ◽  
Edward P. Calomeni ◽  
Shuvro Roy ◽  
Joan Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Collagen Fibril ◽  
Collagen Fibrils ◽  
Collagen Deposition ◽  
Knock Out ◽  
Discoidin Domain Receptor ◽  
Transmission Electron ◽  
Fibril Diameter ◽  
Discoidin Domain Receptor 1

AbstractThe quantity and quality of collagen fibrils in the extracellular matrix (ECM) have a pivotal role in dictating biological processes. Several collagen-binding proteins (CBPs) are known to modulate collagen deposition and fibril diameter. However, limited studies exist on alterations in the fibril ultrastructure by CBPs. In this study, we elucidate how the collagen receptor, discoidin domain receptor 1 (DDR1) regulates the collagen content and ultrastructure in the adventitia of DDR1 knock-out (KO) mice. DDR1 KO mice exhibit increased collagen deposition as observed using Masson’s trichrome. Collagen ultrastructure was evaluated in situ using transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. Although the mean fibril diameter was not significantly different, DDR1 KO mice had a higher percentage of fibrils with larger diameter compared with their wild-type littermates. No significant differences were observed in the length of D-periods. In addition, collagen fibrils from DDR1 KO mice exhibited a small, but statistically significant, increase in the depth of the fibril D-periods. Consistent with these observations, a reduction in the depth of D-periods was observed in collagen fibrils reconstituted with recombinant DDR1-Fc. Our results elucidate how DDR1 modulates collagen fibril ultrastructure in vivo, which may have important consequences in the functional role(s) of the underlying ECM.

scholarly journals The synovial surface of the articular cartilage

2020 ◽  
Vol 64 (3) ◽  
Author(s):  
Petra Rita Basso ◽  
Elena Carava' ◽  
Marina Protasoni ◽  
Marcella Reguzzoni ◽  
Mario Raspanti
Keyword(s):  
Electron Microscopy ◽  
Articular Cartilage ◽  
Articular Surface ◽  
Collagen Fibrils ◽  
Huge Amount ◽  
Thin Sections ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
The Subject

The articular cartilage has been the subject of a huge amount of research carried out with a wide array of different techniques. Most of the existing morphological and ultrastructural data on the this tissue, however, were obtained either by light microscopy or by transmission electron microscopy. Both techniques rely on thin sections and neither allows a direct, face-on visualization of the free cartilage surface (synovial surface), which is the only portion subject to frictional as well as compressive forces. In the present research, high resolution visualization by scanning electron microscopy and by atomic force microscopy revealed that the collagen fibrils of the articular surface are exclusively represented by thin, uniform, parallel fibrils evocative of the heterotypic type IX-type II fibrils reported by other authors, immersed in an abundant matrix of glycoconjugates, in part regularly arranged in phase with the D-period of collagen. Electrophoresis of fluorophore-labeled saccharides confirmed that the superficial and the deeper layers are quite different in their glycoconjugate content as well, the deeper ones containing more sulfated, more acidic small proteoglycans bound to thicker, more heterogenous collagen fibrils. The differences found between the synovial surface and the deeper layers are consistent with the different mechanical stresses they must withstand.

scholarly journals Method to extract minimally damaged collagen fibrils from tendon

2016 ◽  
Vol 3 (4) ◽  
pp. e54
Author(s):  
Yehe Liu ◽  
Nelly Andarawis-Puri ◽  
Steven J. Eppell
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sea Cucumber ◽  
Dark Field ◽  
Collagen Fibrils ◽  
New Method ◽  
Tendon Tissue ◽  
Fibril Diameter ◽  
Rat Tail ◽  
Scanning Electron

 A new method is presented to extract collagen fibrils from mammalian tendon tissue. Mammalian tendons are treated with a trypsin-based extraction medium and gently separated with tweezers in an aqueous solution. Collagen fibrils released in the solution are imaged using both dark-field light microscopy and scanning electron microscopy. The method successfully extracts isolated fibrils from rat tail and patellar tendons. To examine whether the method is likely to damage fibrils during extraction, sea cucumber dermis fibril lengths are compared against those obtained using only distilled water. The two methods produce fibrils of similar lengths. This is contrasted with fibrils being shortened when extracted using a tissue homogenizer. Scanning electron microscopy shows the new method preserves D-banding features on fibril surfaces and that fibril diameter does not vary substantially compared with water extracted fibrils. 

A comparison of the size distribution of collagen fibrils in connective tissues as a function of age and a possible relation between fibril size distribution and mechanical properties

1978 ◽  
Vol 203 (1152) ◽  
pp. 305-321 ◽  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Size Distribution ◽  
Collagen Fibril ◽  
Average Diameter ◽  
Collagen Fibrils ◽  
Diameter Distribution ◽  
Connective Tissues ◽  
Fibril Diameter ◽  
Covalent Crosslinks

Data on the distribution of collagen fibril diameters in various connective tissues have been collected and analysed for common features. The diameter distributions of the collagen fibrils at birth and in the foetal stages of development are unimodal, whereas at maturity the mass-average diameter of the collagen fibrils is generally larger than at birth and the distributions of fibril sizes may be either unimodal or bimodal depending on the tissue. At senescence, few data are available but in most instances both the mean and mass-average diameters of the collagen fibrils are smaller than those at maturity and the fibril distributions are mainly bimodal. The division between tissues showing unimodal or bimodal fibril distributions at maturity does not simply relate to the type I collagen/type II collagen classification, to the distinction between orientated and unorientated material or indeed directly to the levels of stress and strain encountered by the tissue. However, there may prove to be a relation between a bimodal fibril diameter distribution at maturity and the maintenance over long periods of time of either high stress in stretched tissues or low stress in compressed tissues. It has also been noted that the width of the collagen fibril diameter distribution at birth differs between altricious and precocious animals. The ultimate tensile strength of a connective tissue and the mass-average diameter of the constituent collagen fibrils have been shown to have a positive correlation. Further, the form of the collagen fibril diameter distribution can be directly related to the mechanical properties of the tissue. In particular, it is postulated that the size distribution of the collagen fibrils is largely determined by two factors. First, if the tissue is primarily designed to have high tensile strength, then an increase in the diameter of the collagen fibrils will parallel an increase in the potential density of intrafibrillar covalent crosslinks. Consequently large collagen fibrils are predicted to have a greater tensile strength than small fibrils. Secondly, if the tissue is designed to be elastic and hence withstand creep, then a reduction in the diameter of the collagen fibrils will effectively increase the surface area per unit mass of the fibrils thus enhancing the probability of interfibrillar non-covalent crosslinks between the collagen fibrils and the components of the matrix. The idealized description given may indicate how the mechanical properties of a tissue may be interpreted in terms of the collagen fibril diameter distribution.

scholarly journals Ultrastructure Organization of Collagen Fibrils and Proteoglycans of Stingray and Shark Corneal Stroma

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Saud A. Alanazi ◽  
Turki Almubrad ◽  
Ahmad I. A. AlIbrahim ◽  
Adnan A. Khan ◽  
Saeed Akhtar
Keyword(s):  
Electron Microscopy ◽  
Chondroitin Sulfate ◽  
Dermatan Sulfate ◽  
Corneal Stroma ◽  
Collagen Fibrils ◽  
Ultrastructural Organization ◽  
The Mean

We report here the ultrastructural organization of collagen fibrils (CF) and proteoglycans (PGs) of the corneal stroma of both the stingray and the shark. Three corneas from three stingrays and three corneas from three sharks were processed for electron microscopy. Tissues were embedded in TAAB 031 resin. The corneal stroma of both the stingray and shark consisted of parallel running lamellae of CFs which were decorated with PGs. In the stingray, the mean area of PGs in the posterior stroma was significantly larger than the PGs of the anterior and middle stroma, whereas, in the shark, the mean area of PGs was similar throughout the stroma. The mean area of PGs of the stingray was significantly larger compared to the PGs, mean area of the shark corneal stroma. The CF diameter of the stingray was significantly smaller compared to the CF diameter in the shark. The ultrastructural features of the corneal stroma of both the stingray and the shark were similar to each other except for the CFs and PGs. The PGs in the stingray and shark might be composed of chondroitin sulfate (CS)/dermatan sulfate (DS) PGs and these PGs with sutures might contribute to the nonswelling properties of the cornea of the stingray and shark.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

Banded Structures in the Connective Tissue of Meningioma

1976 ◽  
Vol 34 ◽  
pp. 234-235
Author(s):  
C. N. Sun ◽  
H. J. White
Keyword(s):  
Connective Tissue ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Collagen Fibrils ◽  
Lead Citrate ◽  
Connective Tissues ◽  
Native Collagen ◽  
Routine Procedures

Previously, we have reported on extracellular cross-striated banded structures in human connective tissues of a variety of organs (1). Since then, more material has been examined and other techniques applied. Recently, we studied a fibrocytic meningioma of the falx. After the specimen was fixed in 4% buffered glutaraldehyde and post-fixed in 1% buffered osmium tetroxide, other routine procedures were followed for embedding in Epon 812. Sections were stained with uranyl acetate and lead citrate. There were numerous cross striated banded structures in aggregated bundle forms found in the connecfive tissue of the tumor. The banded material has a periodicity of about 450 Å and where it assumes a filamentous arrangement, appears to be about 800 Å in diameter. In comparison with the vicinal native collagen fibrils, the banded material Is sometimes about twice the diameter of native collagen.

scholarly journals DNA AND THE FINE STRUCTURE OF SYNAPTIC CHROMOSOMES IN THE DOMESTIC ROOSTER (GALLUS DOMESTICUS)

1964 ◽  
Vol 23 (1) ◽  
pp. 63-78 ◽  
Author(s):  
James R. Coleman ◽  
Montrose J. Moses
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Fine Structure ◽  
Electron Microscope ◽  
Meiotic Prophase ◽  
Gallus Domesticus ◽  
Feulgen Staining ◽  
Synaptinemal Complex ◽  
Relationship Of ◽  
The Relationship

The indium trichloride method of Watson and Aldridge (38) for staining nucleic acids for electron microscopy was employed to study the relationship of DNA to the structure of the synaptinemal complex in meiotic prophase chromosomes of the domestic rooster. The selectivity of the method was demonstrated in untreated and DNase-digested testis material by comparing the distribution of indium staining in the electron microscope to Feulgen staining and ultraviolet absorption in thicker sections seen with the light microscope. Following staining by indium, DNA was found mainly in the microfibril component of the synaptinemal complex. When DNA was known to have been removed from aldehyde-fixed material by digestion with DNase, indium stainability was also lost. However, staining of the digested material with non-selective heavy metal techniques demonstrated the presence of material other than DNA in the microfibrils and showed that little alteration in appearance of the chromosome resulted from DNA removal. The two dense lateral axial elements of the synaptinemal complex, but not the central one to any extent, also contained DNA, together with non-DNA material.

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