Distribution Of Sulfated Glycosaminoglycans Research Articles

A highly porous type II collagen containing scaffold for the treatment of cartilage defects enhances MSC chondrogenesis and early cartilaginous matrix deposition.

A major challenge in cartilage tissue engineering (TE) is the development of instructive and biomimetic scaffolds capable of driving effective mesenchymal stem cell (MSC) chondrogenic differentiation and robust de novo matrix formation. Type I collagen-based scaffolds are one of the most commonly selected materials given collagen's intrinsic ability to act as an instructive and active biomaterial. However, the chondrogenic potential of these scaffolds does not offer significant improvement over traditional treatments. We propose that taking a biomimetic approach to scaffold development might lead to an improved outcome for enhanced cartilage repair. Therefore, this study aimed to develop innovative type II collagen (CII)-containing scaffolds for enhanced cartilage repair, by incorporating CII and/or hyaluronic acid (HyA) into a type I collagen (CI) framework. Moreover, focus was placed on understanding the potential synergistic effects played by CII in combination with HyA, in terms of MSC chondrogenesis and cartilage-like formation, when both molecules are incorporated into scaffold biomaterials. The newly developed CII-containing scaffold exhibited a highly porous interconnected structure with 99% porosity and similar mechanical properties to previously optimised collagen-based scaffolds. Although all scaffold variants sustained early cartilaginous matrix deposition, the CII-containing scaffolds in the presence of HyA performed best, offering enhanced deposition and distribution of sulphated glycosaminoglycans (sGAG) in vitro by day 28. Taken together, the combination of CII and HyA resulted in the development of a biomimetic scaffold with improved chondrogenic benefits. These simple "off-the-shelf" implants hold great promise to direct enhanced tissue regeneration for the treatment of focal cartilage defects.

Sulphated glycosaminoglycans and proteoglycans in the developing vertebral column of juvenile Atlantic salmon (Salmo salar).

In the present study, the distribution of sulphated glycosaminoglycans (GAGs) in the developing vertebral column of Atlantic salmon (Salmo salar) at 700, 900, 1100 and 1400 d° was examined by light microscopy. The mineralization pattern was outlined by Alizarin red S and soft structures by Alcian blue. The temporal and spatial distribution patterns of different types of GAGs: chondroitin-4-sulphate/dermatan sulphate, chondroitin-6-sulphate, chondroitin-0-sulphate and keratan sulphate were addressed by immunohistochemistry using monoclonal antibodies against the different GAGs. The specific pattern obtained with the different antibodies suggests a unique role of the different GAG types in pattern formation and mineralization. In addition, the distribution of the different GAG types in normal and malformed vertebral columns from 15 g salmon was compared. A changed expression pattern of GAGs was found in the malformed vertebrae, indicating the involvement of these molecules during the pathogenesis. The molecular size of proteoglycans (PGs) in the vertebrae carrying GAGs was analysed with western blotting, and mRNA transcription of the PGs aggrecan, decorin, biglycan, fibromodulin and lumican by real-time qPCR. Our study reveals the importance of GAGs in development of vertebral column also in Atlantic salmon and indicates that a more comprehensive approach is necessary to completely understand the processes involved.

Localization and characterization of sulfated glycosaminoglycans in the body of the earthworm Eisenia andrei (Oligochaeta, Annelida)

The aim of this study was to characterize the compartmental distribution of sulfated glycosaminoglycans (S-GAGs) in adults and their occurrence during the development of the earthworm Eisenia andrei. S-GAGs were extracted from the body of earthworms to identify their composition and the time of their appearance and disappearance in embryonic, newborn, juvenile, and adult earthworms. S-GAGs were also analyzed in earthworm tissue using histochemical metachromatic staining. Purified S-GAGs obtained from the whole body of adult earthworms were composed of chondroitin sulfate (CS) and heparan sulfate (HS). In addition, an unknown, highly sulfated polysaccharide (HSP) was detected. In order to characterize specifically the S-GAG composition in the integument, earthworms were dissected and as much as possible of their viscera was removed. HS and CS were the predominant sulfated polysaccharides in the dissected integument, whereas in viscera, CS, HS and the HSP were found in proportions similar to those identified in the body. The qualitative S-GAG composition in juveniles was similar to that obtained from adult earthworms. CS was the predominant S-GAG in newborn earthworms, accompanied by lesser amounts of HS and by tiny amounts of the HSP. This study provides a detailed descriptive account of the pattern of S-GAG synthesis during development, and also the characterization of the tissue distribution of these compounds in the body of earthworms.

Histochemical characterization of the interphotoreceptor matrix in the retina of Octopus bimaculoides

Proteoglycans, located in the interphotoreceptor matrix (IPM) of vertebrate retinas, mediate interactions between the photoreceptors and retinal pigment epithelium. Molluscan retinas also have an IPM located between apposing rhabdomeres. Like the cone matrix sheath of the vertebrate IPM, the octopus IPM is labeled by peanut agglutinin (PNA) and contains retinoid-binding-like proteins. In this study we demonstrate further similarities of the vertebrate/invertebrate IPM and identify specific molecular components in this extracellular compartment of the octopus retina. For light microscopy, paraffin-embedded sections of octopus retinas were stained with dyes specific for acid mucopolysacharides including Alcian blue and colloidal iron. In addition, sections were digested with enzymes specific for hyaluronan, chondroitin sulfate, and sialoglycoconjugates. Digestion of sections with these enzymes and subsequent staining with Alcian blue or colloidal iron demonstrated the presence of chondroitin sulfate and sialoglycoconjugates in the octopus IPM as well as other retinal layers and cells. At the electron-microscope level we treated retinal tissue with Cuprolinic Blue and observed the distribution of sulfated glycosaminoglycans along the rhabdomere edges facing the IPM and in a more central area of the IPM where microvillous processes of supportive cells are located. The octopus IPM may have importance in retinal structure and may be a scaffolding on which molecular components of the IPM are located.

Changes in the synthesis and distribution of sulphated glycosaminoglycans in human skin fibroblasts upon ascorbate feeding

Changes in the synthesis and distribution of sulphated glycosaminoglycans in human skin fibroblasts upon ascorbate feeding

Distribution of heparin and other sulfated glycosaminoglycans in vertebrates

1. 1. A comparative study on the distribution of sulfated glycosaminoglycans in several tissues of six specimens of different vertebrate classes is reported. 2. 2. Each tissue has a characteristic composition differing from each other regarding the relative amount, type and molecular size of chondroitin 4, 6-sulfate, dermatan sulfate and heparan sulfate. 3. 3. The same tissue from different vertebrates has, in general, the same types of sulfated glycosaminoglycans, but with different molecular weights. 4. 4. Exception to this rule was observed for the distribution of heparin which was present only in a few tissues of the 6 vertebrates studied. 5. 5. The possible involvement of the sulfated glycosaminoglycans in cell recognition and/or adhesiveness is discussed in view of this characteristic distribution.