HSP25 affects the proliferation and differentiation of rat dental follicle cells.
OBJECTIVE
To detect the expression of HSP25 in rat dental follicles both in vivo and vitro, and explore the underlying mechanism of HSP25 on the proliferation and differentiation of rat dental follicle cells (DFCs).


METHODS
Immunohistochemistry was performed to detect the expression of HSP25 in mandibles of postnatal rats on days 1, 3, 5, 7, 9 and 11 in vivo. In vitro, the expression of HSP25 in DFCs was detected by an indirect immunofluorescence assay. Thiazolyl blue tetrazolium bromide (MTT) assay, flow cytometry and alkaline phosphatase (ALP) assay were used to identify the time-course effect mediated by different concentrations of recombinant murine HSP25 of 0, 1, 10, 50 and 100 ng/mL on rat DFCs.


RESULTS
Expression of HSP25 was not detected in dental follicles of the rats until day 5 after birth, but became up-regulated in a time-dependent manner till day 11. HSP25 was detected in the cytoplasm of cultured rat DFCs. No significant difference could be observed in the proliferation of DFCs after stimulation with different concentrations of HSP25 on days 1, 2 and 3 (P > 0.05). HSP25 at concentrations of 50 ng/mL and 100 ng/mL up-regulated the ALP activity of DFCs on day 9 (P < 0.05).


CONCLUSIONS
HSP25-immunoreactivity increased chronologically during the development of dental follicles. The protein had no significant effect on cell proliferation but may play a role in cementoblast/osteoblast differentiation of DFCs.
Du
Yu
Y
Department of Conservative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.
Gu
Hai-Jing
HJ
Gong
Qi-Mei
QM
Yang
Fang
F
Ling
Jun-Qi
JQ
D000469:Alkaline Phosphatase / Q000032:analysis; D000565:Ameloblasts / Q000166:cytology; D000818:Animals; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D004396:Coloring Agents; D003593:Cytoplasm / Q000648:ultrastructure; D003795:Dental Sac / Q000166:cytology* / Q000254:growth & development; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D055551:HSP27 Heat-Shock Proteins / Q000032:analysis / Q000502:physiology*; D009804:Odontoblasts / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013778:Tetrazolium Salts; D013844:Thiazoles; D014083:Tooth Germ / Q000166:cytology; D015854:Up-Regulation / Q000502:physiology
D004396:Coloring Agents; D055551:HSP27 Heat-Shock Proteins; C486114:Hspb1 protein, rat; D013778:Tetrazolium Salts; D013844:Thiazoles; D000469:Alkaline Phosphatase; C022616:thiazolyl blue