[Expression and biological roles of heat shock protein 25 in rat dental follicle cells].
OBJECTIVE
To examine the expression of heat shock protein 25 (HSP-25) in dental rat follicles in vivo and in vitro in order to investigate the possible effect of HSP-25 on cell proliferation and alkaline phosphatase (ALP) activity.


METHODS
The expression of HSP-25 in mandibles of postnatal rats from day 1, 3, 5, 7, 9, 11 was examined by immunohistochemistry in vitro, the expression of HSP-25 in the dental follicle cells was detected by the indirect immunofluorescence method. Methyl thiazolyl tetrazolium (MTT) assay, flowcytometry and ALP assay were used to detect the effect of HSP-25 on rat dental follicles.


RESULTS
HSP-25 expression was absent or weak in rat dental follicle cells at early postnatal stage and present from day 5 till day 11. HSP-25 was detected in the cytoplasm of cultured dental follicle cells. MTT results showed no effect could be detected on dental follicle cell proliferation after stimulation of different concentrations of HSP-25 on day 1, 2, 3. Flowcytometry results also exhibited no difference in cell cycles after stimulation of HSP-25 at 0 microg/L and 100 microg/L. HSP-25 at a concentration of 50 microg/L and 100 microg/L could up-regulate the ALP activity on day 9.


CONCLUSIONS
Expression of HSP-25 increases chronologically in the rat dental follicle cells. HSP-25 locates in the cytoplasm of cultured rat dental follicle cells. HSP-25 has no effect on the proliferation of dental follicle cells, however it can up-regulate the ALP activity.
Du
Yu
Y
Department of Operative Dentistry and Endodontics, Guanghua School and Hospital of Stomatology & Institute of Stomatological Research, Sun Yat-sen University, Guangzhou 510055, China.
Ling
Jun-Qi
JQ
Gu
Hai-Jing
HJ
Gong
Qi-Mei
QM
Xie
Nan
N
D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D003795:Dental Sac / Q000378:metabolism*; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D055551:HSP27 Heat-Shock Proteins / Q000502:physiology*; D007150:Immunohistochemistry; D051381:Rats; D013778:Tetrazolium Salts; D013844:Thiazoles; D015854:Up-Regulation
D055551:HSP27 Heat-Shock Proteins; C486114:Hspb1 protein, rat; D013778:Tetrazolium Salts; D013844:Thiazoles; D000469:Alkaline Phosphatase; C022616:thiazolyl blue