Korean J Anat.  2007 Mar;40(1):27-35.

Thioredoxin Peroxidases are Differentially Expressed in Developing Tooth Germs in Rats

• Kim HJ
• Kang JH
• Jeon SK
• Jung SW
• Kim MS
• Kim WJ
• Oh WM
• Lee EJ
• Jung JY
• Bae CS
• Kim SH

Abstract

Thioredoxin peroxidase (prdx)is an antioxidant defense enzyme and is involved in cell differentiation.We elucidated the localization and expression of prdx in the rat tooth germ,which undergoes dynamic morphological changes during development.Immunohistochemical localization was performed using anti-prdx type I-VI anti bodies,and their expression levels were determined at a transcriptional level.The six types of prdx showed varied immunoreactivities according to cellular stages in the developing tooth germ.Cells of the inner enamel epithelium and dental papilla showed relatively weak immunoreactivity,while ameloblasts and odontoblasts demonstrated strong reactivities to all six types of the enzyme.Of particular note,preameloblasts and preodontoblasts undergoing differentiation in the future cuspforming region of the molar tooth (where the dentin first forms),showed stronger staining than those of the inner enamel epithelium and dental papilla cells in the same tooth germ of the bell stage.The expressions of types I,III and VI prdxs were not changed at the transcription level during tooth development,while those of types II,IV and V p increased in the hard tissue formation stage of tooth germs,compared with the cap or early bell stage.These results suggest that dental hard tissue cells might express prdx enzymes promiscuously and that production of these enzyme isoforms may be implicated in cell signaling between preameloblasts and preodontoblasts,besides serving as antioxidants.

Keyword

Prdx; Developing tooth; Oxidants; Odontoblasts; Ameloblasts

MeSH Terms

Ameloblasts
Animals
Antioxidants
Dental Enamel
Dental Papilla
Dentin
Epithelium
Molar
Odontoblasts
Oxidants
Peroxidases*
Peroxiredoxins
Protein Isoforms
Rats*
Thioredoxins*
Tooth Germ*
Tooth*
Antioxidants
Oxidants
Peroxidases
Peroxiredoxins
Protein Isoforms
Thioredoxins