Immunohistochemical expression of biglycan and decorin in the pulp tissue of human primary teeth during resorption

Abstract

Primary teeth are interesting models that can be used to study physiological and pathological processes involving cells and extracellular matrices in hard and soft tissues. This study investigated the expression and distribution of biglycan and decorin-the non-collagenous components of the extracellular matrix-in primary teeth tissue, during physiological root resorption. Thirty healthy human primary teeth were grouped together according to root length: Group I -two-thirds root length, Group II -one-third root length, and Group III -teeth with no root. The streptavidin-biotin-peroxidase immunohistochemical method was used with antibodies against the previously named antigens. The proteoglycans studied were found in the pulp and dentin extracellular matrix in all groups without any differences in the proteins, among the groups. Biglycan was observed mainly in predentin and in pulp connective tissue in the resorption area. In addition, decorin was observed mainly in pulp connective tissue, but near the resorption area. Biglycan and decorin were distributed differentially in the dental tissues. The present immunohistocytochemical data, combined with previously reported data, suggest that these proteoglycans could be involved in regulating the physiological resorption process in healthy primary teeth.

Biglycan in the Skeleton

“…[111][112][113][114] Biglycan is a major constituent of unmineralized dentin (predentin), where it restricts collagen fibrillogenesis and promotes dentin formation and mineralization. [115][116][117] In dental tissues of 5-day to 2-month old rats, the expression of Biglycan remains stable in predentin and in the pulp space, 118 whereas the expression of other SLRPs (Decorin, Fibromodulin and Lumican) have only been identified during dentin and cementum mineralization. 119 Deletion of either Bgn and/or Dcn in mice leads to hypomineralized dentin formation.…”

“…17 During physiological root resorption of healthy human primary teeth, there is an upregulation in Biglycan expression in predentin and in pulp connective tissue, pointing to its involvement in regulating the resorption process. 117 Considering the prominent expression of Biglycan in many craniofacial tissues, it is not surprising that mutations in the human BGN gene cause varying degrees of craniofacial asymmetry and macrocephaly, as well as gingival hypertrophy. 125 The temporomandibular joint (TMJ) is a unique articulating joint in the craniofacial complex that is essential for proper mastication and speech.…”