Detection of dentin sialoprotein in rat periodontium.
Cloning and sequencing of the cDNA indicates that dentin sialophosphoprotein (DSPP) is a precursor of both dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). Dentin sialophosphoprotein must be proteolytically processed to form these two extracellular matrix (ECM) proteins. Numerous studies led us to conclude that DSP (and DSPP) are exclusively expressed by odontoblasts and preameloblasts. However, recent observations suggest a wider distribution. To test this hypothesis, we conducted systematic studies on rat first molar during root formation with immunohistochemical techniques using specific anti-DSP polyclonal and monoclonal antibodies. We also performed in situ hybridization, using high-stringency RNA probes to detect DSP transcripts. Immunohistochemical studies demonstrated that DSP is not only localized in odontoblasts, dentin ECM and preameloblasts, but also in alveolar bone, cellular cementum, osteocytes, cementocytes, and their matrices. The results of in situ hybridization were consistent with those from immunohistochemistry, showing the expression of DSP transcripts in osteoblasts of alveolar bone, fibroblasts in periodontal ligament and cementoblasts in cellular cementum. Together, these observations suggest that DSP is involved in formation of the periodontium as well as tooth structures.
Baba
Otto
O
Department of Endodontics and Periodontics, The University of Texas-Houston Health Science Center Dental Branch, Houston, Texas, USA. Oto.Baba@uth.tmc.edu
Qin
Chunlin
C
Brunn
Jan C
JC
Jones
Jarrod E
JE
Wygant
James N
JN
McIntyre
Bradley W
BW
Butler
William T
WT
D000539:Alveolar Process / Q000166:cytology; D000565:Ameloblasts / Q000166:cytology; D000818:Animals; D003739:Dental Cementum / Q000166:cytology; D005109:Extracellular Matrix / Q000737:chemistry; D016326:Extracellular Matrix Proteins; D005347:Fibroblasts / Q000166:cytology; D009804:Odontoblasts / Q000166:cytology; D009805:Odontogenesis / Q000502:physiology; D010006:Osteoblasts / Q000166:cytology; D010011:Osteocytes / Q000166:cytology; D010513:Periodontal Ligament / Q000166:cytology; D010519:Periodontium / Q000166:cytology*; D010750:Phosphoproteins / Q000032:analysis; D011498:Protein Precursors / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012795:Sialoglycoproteins / Q000032:analysis*; D014092:Tooth Root / Q000166:cytology; D014158:Transcription, Genetic; D000099311:Dentin Sialophosphoprotein
D016326:Extracellular Matrix Proteins; D010750:Phosphoproteins; D011498:Protein Precursors; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein; C017630:phosphophoryn