title: Immunohistochemical expression of heat shock proteins in the mouse periodontal tissues due to orthodontic mechanical stress.
abstract: The histopathology of periodontal ligament of the mouse subjected to mechanical stress was studied. Immunohistochemical expressions of HSP27 and p-HSP27 were examined. Experimental animals using the maxillary molars of ddY mouse by Waldo method were used in the study. A separator was inserted to induce mechanical stress. After 10 minutes, 20 minutes, 1 hour, 3 hours, 9 hours and 24 hours, the regional tissues were extracted, fixed in 4% paraformaldehyde and 0.05M phosphate-buffered fixative solution. Paraffin sections were made for immunohistochemistry using HSP27 and p-HSP27. In the control group, the periodontal ligament fibroblasts expressed low HSP27 and p-HSP27. However, in the experimental group, periodontal ligament fibroblasts expressed HSP27 10 minutes after mechanical load application in the tension side. The strongest expression was detected 9 hours after inducing mechanical load. p-HSP27 was also expressed in a time-dependent manner though weaker than HSP27. The findings suggest that HSP27 and p-HSP27 were expressed for the maintenance of homeostasis of periodontal ligament by the activation of periodontal ligament fibroblasts on the tension side. It also suggests that these proteins act as molecular chaperones for osteoblast activation and maintenance of homeostasis.
authors.affiliation: Hard Tissue Pathology Unit, Matsumoto Dental University, Graduate School of Oral Medicine, 1780 Hirooka-Gobara, Shiojiri, 399-0781 Japan. mura@po.mdu.ac.jp
authors.forename: R
authors.initials: R
authors.lastname: Muraoka
authors.forename: K
authors.initials: K
authors.lastname: Nakano
authors.forename: S
authors.initials: S
authors.lastname: Kurihara
authors.forename: K
authors.initials: K
authors.lastname: Yamada
authors.forename: T
authors.initials: T
authors.lastname: Kawakami
mesh_terms: D000818:Animals; D055551:HSP27 Heat-Shock Proteins / Q000032:analysis* / Q000502:physiology; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D010513:Periodontal Ligament / Q000737:chemistry* / Q000473:pathology; D010766:Phosphorylation; D013314:Stress, Mechanical; D014087:Tooth Movement Techniques
chemical_list: D055551:HSP27 Heat-Shock Proteins; C486699:Hspb2 protein, mouse