The active role of gingival proteoglycans in periodontal disease

The quantitatively major extracellular non-fibrous macromolecules of human gingivae are the proteoglycans. This class of macromolecules have been considered to be paramount in maintaining many tissue functions and are therefore presumably of prime importance in regulating the physiology of the gingivae which in turn regulates its structural integrity. Such an active role for the proteoglycans has been hitherto widely ignored in the standard dental texts, which assume the intercellular material of gingivae to be "inert" and "amorphous". We pose a question: "Is it possible that the intercellular proteoglycans of gingival epithelium and connective tissue play a major role in the regulation of the initiation and sequelae of periodontal disease?" Consequently, we hypothesize that, in gingivae affected by the destructive inflammatory processes seen in periodontal disease, the status of the extracellular proteoglycans of the gingival epithelium specifically determines the rate of diffusion of extraneous inflammagens or tissue destructive enzymes from the oral cavity. By analogy, the response of the underlying connective tissue to these solutes diffusing into it will be regulated by the state of its extracellular proteoglycan and indeed, may in turn, effect the maintenance of the closely apposed epithelial integrity.