Transient co-localization of c-Jun N-terminal kinase and c-Jun with heat shock protein 70 in pulp cells during apoptosis.
The c-Jun N-terminal kinase (JNK) pathway and heat-shock proteins (HSPs) are involved in stress-induced apoptosis. Here we examined the association of JNK, c-Jun, and anti-apoptotic HSPs with pulp apoptosis during wound healing. In normal pulp, c-Jun was activated only in a few pulp cells, but JNK was not. HSP70 was expressed in the cytoplasm of pulp cells. One day after injury, active JNK and c-Jun were detected in apoptotic pulp cells, whereas HSP70 was detected in non-apoptotic cells. We also found the translocation of HSP70 into nuclei of pulp cells, and co-localization with active JNK and c-Jun. Four days after injury, active JNK and c-Jun disappeared in pulp cells, and HSP70 was relocalized from nuclei to the cytoplasm. These results suggest that the JNK pathway may be one of the compartments inducing apoptosis in pulp cells, and that HSP70 may have an inhibitory role in the apoptosis of pulp cells during wound healing.
Kitamura
C
C
Department of Operative Dentistry and Endodontics, Kyushu Dental College, 2-6-1 Manazuru, Kokurakita, Kitakyushu 803-8580, Japan. chi-aki-k@kyu-dent.ac.jp
Ogawa
Y
Y
Nishihara
T
T
Morotomi
T
T
Terashita
M
M
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D003737:Dental Cavity Preparation / Q000009:adverse effects; D003782:Dental Pulp / Q000293:injuries / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D020287:In Situ Nick-End Labeling; D048031:JNK Mitogen-Activated Protein Kinases; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013047:Specific Pathogen-Free Organisms; D014945:Wound Healing / Q000502:physiology
D018840:HSP70 Heat-Shock Proteins; D016755:Proto-Oncogene Proteins c-jun; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases