Unique genes induced by mechanical stress in periodontal ligament cells.
OBJECTIVE
The aim of this study is to isolate mechanical stress-induced genes (MSGens) from human periodontal ligament (PDL) cells and to analyze profiles of the mRNA expression of these genes.


BACKGROUND
Differential expression of genes in PDL cells under physiological stress such as occlusal force is thought to be orchestrated not only for the remodeling of PDL itself but also for the repair and regeneration of periodontal tissues. However, little is known about the genes expressed in PDL cells under mechanical stress.


METHODS
The cDNA from mechanical stress-applied human PDL cells was subtracted against the cDNA from static control cells. The subtracted cDNA was amplified by polymerase chain reaction (PCR) and cloned for further analysis.


RESULTS
Among 68 independent clones isolated, 15 contained DNA fragments greater than 250 bp. Reverse Northern analysis revealed a marked induction of MSGen-15 and MSGen-28 mRNA expression in the mechanical stress-applied cells. However, little difference in the magnitude of expression for the other MSGens was detected between the stress-applied cells and the control cells. After nucleotide sequencing and the analysis of homology with known genes, five clones were identified; ribosomal protein S27 (MSGen-9), MRG 15 (MSGen-15), androgen-binding protein (MSGen-18), cathepsin H (MSGen-28), and cytochrome c (MSGen-47). Interestingly, it has been reported that MRG 15 is a novel transcription factor involved in the regulation of cell growth and senescence. The remaining 10 clones, classified into six sequence types, had no significant homology with any known genes.


CONCLUSIONS
These results suggest that many known and unknown genes are expressed in response to mechanical stress in PDL cells, and that a transcription factor, MRG 15, may be responsible for molecular events in PDL cells under mechanical stress.
Myokai
Fumio
F
Department of Periodontal Science, Okayama University Graduate School of Medicine and Dentistry, Shikata-cho, Okayama, Japan.
Oyama
Masataka
M
Nishimura
Fusanori
F
Ohira
Taisuke
T
Yamamoto
Tadashi
T
Arai
Hideo
H
Takashiba
Shogo
S
Murayama
Yoji
Y
D000328:Adult; D000727:Androgen-Binding Protein / Q000235:genetics; D001732:Bite Force; D056655:Cathepsin H; D002403:Cathepsins / Q000235:genetics; D018929:Cell Culture Techniques; D003546:Cysteine Endopeptidases / Q000235:genetics; D003574:Cytochrome c Group / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D008667:Metalloproteins / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D010513:Periodontal Ligament / Q000378:metabolism* / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D013314:Stress, Mechanical; D014157:Transcription Factors / Q000235:genetics
D000727:Androgen-Binding Protein; D003574:Cytochrome c Group; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C470833:MORF4L1 protein, human; D008667:Metalloproteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C083686:RPS27 protein, human; D012269:Ribosomal Proteins; D014157:Transcription Factors; D002403:Cathepsins; D003546:Cysteine Endopeptidases; C534126:CTSH protein, human; D056655:Cathepsin H