Artificial dental pulp exposure injury up-regulates antigen-presenting cell-related molecules in rat central nervous system.
BACKGROUND
Bacterial infection and resulting inflammation of the dental pulp might not only trigger neuroimmune interactions in this tissue but also sensitize the central nervous system (CNS) such as the thalamus via nociceptive neurons. Thus, immunopathologic changes in the rat thalamus that take place after pulp inflammation were investigated.


METHODS
Pulp exposure was made in mandibular right first molars of 5-week-old Wistar rats. After 24 hours, the thalamus was retrieved and subjected to either immunohistochemistry for class II major histocompatibility complex (MHC) molecules and glial fibrillary acidic protein (GFAP) or mRNA expression analysis of antigen-presenting cell-related molecules and N-methyl-D-aspartate receptor 2D subunit (NR2D) by means of reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR.


RESULTS
At 24 hours after pulp exposure, the density of class II MHC molecule-expressing and GFAP-expressing cells was increased in the contralateral thalamus. Gene expression analysis revealed the up-regulation of class II MHC molecules, CD80, CD83, CD86, and NR2D in the contralateral thalamus, as compared with the ipsilateral thalamus.


CONCLUSIONS
These results suggest the signal of pulp inflammation induces neuronal activation in the CNS.
Kaneko
Tomoatsu
T
Pulp Biology and Endodontics, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. tomoendo@tmd.ac.jp
Kaneko
Mitsuhiro
M
Chokechanachaisakul
Uraiwan
U
Kawamura
Jun
J
Kaneko
Reika
R
Sunakawa
Mitsuhiro
M
Okiji
Takashi
T
Suda
Hideaki
H
D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology* / Q000276:immunology; D003789:Dental Pulp Exposure / Q000276:immunology* / Q000473:pathology; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008334:Mandible; D008963:Molar; D015213:Neuroimmunomodulation / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013788:Thalamus / Q000166:cytology / Q000276:immunology / Q000378:metabolism*
D005904:Glial Fibrillary Acidic Protein; D000949:Histocompatibility Antigens Class II; C533282:N-methyl D-aspartate receptor subtype 2D, rat; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate