Immunohistochemical Changes of Heat Shock Protein 27 Expression in the Mouse Periodontal Tissues Exposed to Orthodontic Mechanical Stress

Abstract

Orthodontic mechanical stress was exposed on mouse molars and histopathological changes as well as the expressions of HSP27 and p-HSP27 in the periodontal tissues were examined after removal of mechanical stress. The increased in mechanical stress up to 3 hours led to pathological changes that caused a space in between stretched periodontal ligament fibrous bundles and fibroblasts as well as narrowing of the periodontal ligament space. Degenerative changes were also occurred in the pressure side. Pathological changes did not only occur due to mechanical stress but also at the time of the release of mechanical stress exposure which increased over time. In the control group, both HSP27 and p-HSP27 were negative in the pressure side after mechanical stress was released 3 hours later. On the other hand, the tension side showed a strong positive reaction. The proteins were also expressed after 20 min, 1 hour, 3 hours and 9 hours. The strongest expression was observed 24 hours. A decreased in the intensity of expression was observed 3 days and 1 week later. The results suggest that HSP27 plays an important role in the recovery of injured cells in the periodontal tissues.

HSP47 as a Possible Molecular Chaperone for the Collagen Synthesis in the Mouse Periodontal Ligament Cells due to Orthodontic Force

“…In the past, we carried out animal experiments to establish an immunohistological basis for orthodontic treatment. We investigated various proteins expressed in the mouse periodontal tissue after application of mechanical stress simulating orthodontic treatment [2][3][4][5][6][7][8][9][10][11]. However, cellular responses related to repair of the injurious effects of mechanical stress on PDL fibroblasts during corrective treatment have barely been investigated.…”

“…In orthodontic treatment, remodeling of the periodontal tissue is brought about by mechanical stress due to a correction device and, because of tissue responses to this mechanical stress, the tooth moves [1]. The periodontal tissue responds to different types of stimulus such as mechanical stress and inflammation, to maintain homeostasis, and expresses various proteins to bring about active remodeling of the periodontal tissue [2][3][4][5][6][7][8][9][10][11]. It is important to grasp the kinetics of various factors expressed in the periodontal tissue during orthodontic treatment, as a biochemical basis.…”

“…HSPs are involved in the defense and repair of injured cells and are thought to contribute to the control of cellular function [19,20]. However, while HSPs are involved in regulatory cellular responses to injurious stimuli, there are few reports regarding their expression state in periodontal ligament (PDL) tissue accompanying orthodontic tooth movement or their roles [2,11,16]. The principal constituent of the extracellular matrix of the PDL is collagen, which acts to alleviate mechanical stresses such as occlusal forces and mechanical corrective forces.…”

Immunohistochemical Expression of Osterix Appearing in the Mouse Orthodontic Periodontal Tension Sides

“…Furthermore, the osteogenesis related factors were also examined using immunohistochemical analysis, such as Runx2, Msx2 5-7) , BMP-2, BMP-4, Smad, p-Smad 8,9) and ALP. Furtheremore, HSPs and p-HSPs [10][11][12][13] were also examined on the orthodontic periodontal tension side.…”

“…Thus, some researchers have examined the immunohistochemical profile change of experimental orthodontic periodontal tissues using animal model. Examined data have been published regarding Runx2 and Msx2 [5][6][7] , BMPs and Smad 8,9) and HSPs [10][11][12][13] .…”