Pressure simulation of orthodontic force in osteoblasts: a pilot study.
OBJECTIVE
To elucidate the RUNX2 gene expression induction in human osteoblasts after mechanical loading.


METHODS
Using a stringent pulse-chase protocol human osteoblasts were exposed to centrifugal pressure force for 30 and 90 min. Untreated control cells were processed in parallel. Before, and at defined times after centrifugation, total RNA was isolated. RUNX2 gene expression was measured using real-time quantitative reverse transcriptase polymerase chain reaction. The stress/control ratio was used to illustrate possible stimulatory or diminishing effects of force application.


RESULTS
Immediately after 30 min of force application the RUNX2 gene expression was induced by a factor of 1.7 +/- 0.14 as compared with the negative control. This induction decreased rapidly and reached its pre-load levels within 30 min. Longer force applications (up to 90 min) did not change the RUNX2 gene expression.


CONCLUSIONS
In mature osteoblasts centrifugal pressure force stimulates RUNX2 gene expression within a narrow time frame: loading of mature cells results in a temporary increase of RUNX2 expression and a fast downregulation back to its pre-load expression level. With this pilot study the gene expression behavior after mechanical stimuli could be determined with a simple laboratory setup.
Department of Orthodontics, Center for Craniofacial Genetics, University of Regensburg, Germany. uwe.baumert@klinik.uni-regensburg.de
U
U
Baumert
I
I
Golan
B
B
Becker
B P
BP
Hrala
M
M
Redlich
H A
HA
Roos
A
A
Palmon
E
E
Reichenberg
D
D
Müssig
D002478:Cells, Cultured; D002498:Centrifugation; D050659:Core Binding Factor Alpha 1 Subunit; D003799:Dental Stress Analysis; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D010006:Osteoblasts / Q000378:metabolism / Q000502:physiology*; D010865:Pilot Projects; D011312:Pressure; D012313:RNA / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014087:Tooth Movement Techniques; D014157:Transcription Factors / Q000096:biosynthesis*
D050659:Core Binding Factor Alpha 1 Subunit; D009363:Neoplasm Proteins; D014157:Transcription Factors; D012313:RNA