title: The Ca(2+)-binding protein calretinin is selectively enriched in a subpopulation of the epithelial rests of Malassez.
abstract: During tooth development, the inner and outer enamel epithelia fuse by mitotic activity to produce a bilayered epithelial sheath termed Hertwig's epithelial root sheath (HERS). The epithelial rests of Malassez (ERM) are the developmental residues of HERS and remain in the adult periodontal ligament (PDL). Although the cellular regulation of the Ca(2+)-binding proteins parvalbumin, calbindin-D28k, and calretinin has been reported in the inner and outer enamel epithelia during tooth development, an involvement of Ca(2+)-binding proteins in the ERM has not so far been characterized. Among the three Ca(2+)-binding proteins tested (calbindin D28k, parvalbumin, calretinin), we have only been able to detect calretinin in a subpopulation of adult rat molar ERM, by using quantitative immunohistochemical and confocal immunofluorescence techniques. TrkA (a marker for ERM) is present in numerous epithelial cell clusters, whereas calretinin has been localized in the cytosol and perinuclear region of a subpopulation of TrkA-positive cells. We conclude that, in inner and outer enamel epithelial cells, Ca(2+) is regulated by calbindin, parvalbumin, and calretinin during tooth development, whereas in the ERM of adult PDL, Ca(2+) is regulated only by calretinin. The expression of Ca(2+)-binding proteins is restricted in a developmental manner in the ERM.
authors.affiliation: Department of Operative Dentistry, Periodontics and Endodontics, Heinrich Heine University, Moorenstrasse 5, 40225 Düsseldorf, Germany. yueksel.korkmaz@uni-duesseldorf.de
authors.forename: Yüksel
authors.initials: Y
authors.lastname: Korkmaz
authors.forename: Franz-Josef
authors.initials: FJ
authors.lastname: Klinz
authors.forename: Thomas
authors.initials: T
authors.lastname: Beikler
authors.forename: Thorsten
authors.initials: T
authors.lastname: Blauhut
authors.forename: Kurt
authors.initials: K
authors.lastname: Schneider
authors.forename: Klaus
authors.initials: K
authors.lastname: Addicks
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Bloch
authors.forename: Wolfgang H-M
authors.initials: WH
authors.lastname: Raab
mesh_terms: D000565:Ameloblasts / Q000378:metabolism; D000818:Animals; D015415:Biomarkers; D064092:Calbindin 1; D064032:Calbindin 2; D064026:Calbindins; D002454:Cell Differentiation; D004658:Enamel Organ / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D008297:Male; D018613:Microscopy, Confocal; D009412:Nerve Fibers / Q000378:metabolism; D009805:Odontogenesis; D010320:Parvalbumins / Q000378:metabolism; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D014070:Tooth / Q000033:anatomy & histology / Q000378:metabolism
chemical_list: D015415:Biomarkers; C576500:Calb1 protein, rat; C576512:Calb2 protein, rat; D064092:Calbindin 1; D064032:Calbindin 2; D064026:Calbindins; D010320:Parvalbumins; D064030:S100 Calcium Binding Protein G