Keratan sulfate

About: Keratan sulfate is a research topic. Over the lifetime, 1253 publications have been published within this topic receiving 57984 citations. The topic is also known as: keratan sulfate & KS.

Topographical distribution of sulfated glycosaminoglycans in the surface layers of the human temporomandibular joint. A histochemical study of an autopsy material.

Abstract: . The right temporomandibular joint (TMJ) was removed at autopsy from 18 individuals and the articular surfaces were scored for macroscopic lesions. Soft tissue specimens were cut out of the medial, lateral and posterior parts of the temporal and condylar components and frozen. The sections were stained with toluidine blue (1-N HC1 solution) and with alcian blue (CEC method) for sulfated glycosaminoglycans. The sections were examined for inter- and pericellular metachromasia and alcian blue staining. Macroscopic surface lesions were found in 14 of the joints. The highest score of inter-and pericellular metachromasia was found in the anterior parts of the joints and a negative correlation was found between the score of surface lesions and that of intercellular metachromasia. Pericellular metachromasia was found mainly in the mineralized cartilage and cartilage layers of the articular surface. Although the CEC values of pericellular staining commonly reached a level indicating the presence of keratan sulfate, the majority of the CEC values found corresponded to those of chondroitin-dermatan sulfate. It was concluded that sulfated GAG are localized mainly to the anterior part of the TMJ and that macroscopic TMJ surface lesions are associated with a reduction of sulfated glycosaminoglycans.

Experimental induction of anterior disk displacement of the rabbit craniomandibular joint: an immuno-electron microscopic study of collagen and proteoglycan occurrence in the condylar cartilage.

Abstract: Background: Results from our previous studies suggest that surgical induction of anterior disk displacement (ADD) in the rabbit craniomandibular joint (CMJ) leads to histopathological alterations consistent with osteoarthritis. In addition, molecular changes in collagens and glycosaminoglycans (GAGs) were observed using immunohistochemistry. The purpose of the present study was to further characterize those molecular changes in collagens and GAGs using immuno-electron microscopy. Methods: The right joint of 15 rabbits was exposed surgically and all discal attachments were cut except for the posterior attachment (the bilaminar zone). The disc was then repositioned anteriorly and sutured to the zygomatic arch. The left joint was used as a sham-operated control. Ten additional joints were used as non-operated controls. Mandibular condyles were removed 2 weeks following surgery and processed for light and immuno-electron microscopy using colloidal gold-labeled antibodies against collagen type I, II, VI and IX and against keratan sulfate, chondroitin-4 and -6-sulfate, and link protein. Results: Light microscopic results showed osteoarthritic changes. Immuno-electron microscopy of osteoarthritic cartilage demonstrated a decline in type II collagen, the abnormal presence of type I collagen and loss of type VI and IX collagens. Quantitative colloidal gold immuno-electron microscopy confirmed the depletion of keratan sulfate, chondroitin-4 and -6-sulfate, and link protein in osteoarthritic cartilage. Conclusion : Anterior disk displacement leads to molecular alterations in both the collagen and the proteoglycans of rabbit condylar cartilage characteristic of osteoarthritis in other synovial joints. These alterations are consistent with loss of the shock absorber function of the cartilage and injury of the underlying bone.

Structure and biological functions of keratan sulfate proteoglycans.

Abstract: The skeletal and corneal keratan sulfate proteoglycans show a different metabolic and structural heterogeneity. The domain structure of the carbohydrate chain has been shown to be different in various animal species. There are two major types of skeletal keratan sulfate proteoglycans with and without fucose. The protein cores of the corneal chicken keratan sulfate proteoglycan (lumican) and those of another small keratan sulfate proteoglycan (fibromodulin) have been sequenced. Keratan sulfate oligosaccharides belong to the members of an antigen family of the poly-N-acetyllactosamine series. Monoclonal antibodies and immunoassay procedures for keratan sulfate proteoglycans have been prepared. In osteoarthritis, no significant specific increase of keratan sulfate has been found. Keratan sulfate is a functional substitute for chondroitin sulfate in O2-deficient tissues.

The proteinpolysaccharides of human costal cartilage

Abstract: Water-soluble proteinpolysaccharides, called PPL, can be extracted from bovine nucleus pulposus in yields of 45%, and from bovine nasal cartilage in yields of 37% of the dry tissue weight. From human costal cartilage only 7% can be extracted. The method used to separate PPL from each of the first two tissues into four distinct fractions separates the PPL of human costal cartilage into four fractions called PPL 3, PPL 4, PPL 5, and PPL 6, which show an increase in protein content, a decrease in chondroitin sulfate content, a nearly constant keratan sulfate content, and an increase in ease of sedimentability and molecular weight. From each of the three tissues mentioned. PPL 3 has a similar amino acid profile and so does PPL 5, but PPL 5 differs from PPL 3 in having a lower content of serine and higher contents of aspartic acid, tyrosine, and arginine. A more extensive effort to characterize these products has been made by analytical ultracentrifugation, and this has led to a further fractionation of PPL 5. Treatment of the cartilage residue or the water-insoluble protein polysaccharide called PPH, with neutral NH(2)OH solution releases water-soluble protein polysaccharides which in composition resemble PPL 4. The water-insoluble residue left after NH(2)OH treatment, when treated with collagenase, yields two soluble products, one resembling PPL 5 in composition, the other with a much lower chondroitin sulfate and much higher keratan sulfate content. The possibility is suggested that in human costal cartilage, binding of some forms of PPL to collagen may occur.

The Role of Lumican in Ocular Disease

Abstract: Lumican is keratan sulfate proteoglycan of the small leucine rich proteoglycan family. Through studies in animal models lumican has been found to be critical in maintaining corneal clarity. It maintains ordered collagen fibrils which are vital in keeping the cornea transparent. It may also be important in primary open angle glaucoma influencing aqueous outflow. Lumican deficiency in mice results in increased axial length with fibromodulin deficiency and thinner sclerae. There is evidence suggesting that this characteristic may be pertinent in humans and lumican gene polymorphisms could be related to high myopia. Lumican plays a fundamental role in inflammation and wound healing. It localises macrophages to the site of corneal injury and recruits neutrophils in lipopolysaccharide-induced keratitis in mice. It has also been shown to bind lipopolysaccharide which may be critical in inflammatory diseases such as uveitis. Lumican is also important in wound healing revealing decreased synthesis in scar tissue and mediating Fas-Fas ligand interactions. It is present in human placenta and amniotic membrane suggesting that it may ensure viable amniotic membrane grafts. Lumican may also be involved in the formation of posterior capsular opacification following cataract surgery. Research into the pivotal role of lumican in the pathogenesis of ocular disease has resulted in greater understanding of the key role which proteoglycans play in human disease.