Ultrastructural localization of glycosaminoglycans in human gingival connective tissue using Cupromeronic blue

Abstract

Human gingiva was stained with cupromeronic blue according to Scott's critical electrolyte concentration technique in order to localize glycosaminoglycans (GAG) in the electron microscope. Identification was performed by digestion with chondroitinase AC, ABC and heparinase. The GAG were localized in three compartments of the connective tissue: the supra-alveolar fiber apparatus, the loose connective tissue and the basement membranes. In the supra-alveolar fiber apparatus, consisting mainly of densely packed parallel collagen fibrils, dermatan sulfate GAG are regularly attached to the d-band of the collagen fibrils. The precipitates (6-7 nm in diameter) aggregate to thicker precipitates (up to 16 nm), thus possibly providing stability to the fiber system. In the loose connective tissue with sparse collagen fibrils dermatan and chondroitin sulfate GAG form very large precipitates (up to 30 nm in diameter and 400 nm length) which interconnect the few collagen fibrils. The basement membranes of the epithelium and capillary endothelium contain heparan sulfate GAG as fine precipitates (4-6 nm in diameter) which form a meshwork. These findings are consistent with the Scott model (1) for the interactions among glycans and glycans and collagen fibrils in connective tissues.

Molecular and cell biology of the gingiva

“…Dermatan sulfate appears to be localized closely associated with collagen fibers and is particularly evident at the epithelial connective tissue interface. In contrast, heparan sulfate is localized primarily in the basement membranes of epithelium and capillary endothelium (57). Specific proteoglycans have also been identified by immunohistochemistry within the gingival tissues and include decorin, biglycan, versican, syndecan, CD-44 and perlecan (71,152).…”

Enhanced propagation of Granulicatella adiacens from human oral microbiota by hyaluronan

“…Hyaluronan (hyaluronic acid, HA), composed of glucuronate and N -acetyl glucosamine (GlcNAc), a highly abundant component in ECM, is a unique nonsulfated GAG, not covalently attached to the proteins 11 , 14 , 15 . Several GAGs are frequently detected in the oral environment, such as saliva 14 and gingiva 16 .…”