The proteoglycans of human cementum: immunohistochemical localization in healthy, periodontally involved and ageing teeth

Abstract

Cementum is believed to play a regulatory role in periodontal regeneration through a variety of macromolecules present in its extracellular matrix (ECM), among which are the proteoglycans (PG). The PG of human cementum have not been fully characterized. This study has used a standard indirect immunoperoxidase technique to investigate the presence and distribution of PG species within the ECM of human cementum. Freshly extracted human permanent teeth were separated into 8 age groups; each group was subdivided to include healthy and periodontally involved teeth, which were then fixed, demineralized and wax-embedded. Sections were incubated with polyclonal antibodies recognizing protein core epitopes in the large chondroitin sulphate PG versican and the small interstitial PG decorin, biglycan, fibromodulin and lumican. Immunoreactivity to versican, decorin, biglycan and lumican was evident at the borders and lumina of a proportion of lacunae and canaliculi surrounding cementocytes in cellular cementum, as well as on inserted periodontal ligament (PDL) fibres. Biglycan was also present along incremental lines in cellular cementum, whereas staining for fibromodulin was negative. In acellular cementum, no immunoreactivity was evident with any of the antibodies used except on inserted PDL fibres. These results indicate that versican, decorin, biglycan and lumican are components of the ECM of cellular, but not of acellular cementum. Neither age nor periodontal diseases appear to qualitatively influence the PG population of cementum. The distribution of PG epitopes around a proportion of cementocytes suggests the existence of different cementocyte subpopulations, or a differential response of these cells to yet undefined stimuli.

Immunohistochemical and biochemical assay of versican in human sound predentine/dentine matrix

“…Similar PGs have been found in other connective tissues (Zimmermann et al, 1989;Shinomura et al, 1990;Zimmermann et al, 1994;Landolt et al,1995) and recent studies have shown that, within the dental tissues, versican has been localised in gingival fibroblasts culture, dental pulp complex (Yamauchi et al, 1997;Bartold et al, 1995;Shibata et al, 2000;Shibata et al, 2002;Robey et al, 1993;Ababneh et al, 1999;Cheng et al, 1999), dentine (Waddington et al, 2003), cementum (Ababneh et al, 1999;Cheng et al, 1999) and periodontal ligament (Sato et al, 2002).…”

“…In fact, versican is a member of an important pool of PGs that led to the initial formation of the extracellular matrix (Zimmermann et al, 1989) by capturing a temporal space for succeeding tissues/cells embryonic (Shinomura et al, 1990;Landolt et al, 1995). Despite versican localisation as been demonstrated in dental pulp (Shibata et al 2000(Shibata et al , 2002Robey et al, 1993), periodontal ligament (Sato et al, 2002;Shibata et al, 1999), dentine (Waddinghton et al, 2003) and cementum (Ababneh et al, 1999;Cheng et al, 1999), its function and precise distribution within the sound dentine are still unclear.…”

Fibromodulin and Biglycan Modulate Periodontium through TGFβ/BMP Signaling

“…With the loss of Fmod and Bgn, PDL tissues exhibited more spaces between and within collagen fibril bundles, possibly because of the decreased quality and quantity of cross-links formed by SLRPs. In WT mice, Fmod and Bgn were expressed more intensely in the insertion region of the collagen fibrils into the cementum (data not shown), an observation consistent across species (Ababneh et al, 1999;Matias et al, 2003), suggesting that SLRPs play a role in PDL-cementum attachment. SLRP-mediated collagen cross-linking not only holds fibrils tighter, but also protects collagens from enzyme degradation (Geng et al, 2006).…”

Incremental distribution of strontium and zinc in great ape and fossil hominin cementum using synchrotron X-ray fluorescence mapping

“…Demineralised and stained thin sections of cementum [see figures 11.2 and 11.13 in 7] demonstrate that even the unmineralised organic cementum matrix contains incremental markings visible within it. Biglycan is associated with incremental markings in cellular cementum and along with other glycosaminoglycans (decorin, lumican, and versican) is associated with cellular but not acellular cementum growth [9,16]. Cementoblasts forming acellular cementum exert much stricter regulation of local inorganic pyrophosphate levels than cementoblasts forming cellular cementum, which has a profound influence on rates of mineralisation [5].…”