[Effects of calcitriol on the expression of vitamin D receptor, RANKL and osteoprotegerin in human periodontal ligament cells].
OBJECTIVE
To study the effects of 1, 25-dihydroxyvitamin D(3) (VD(3)) on the expression of vitamin D receptor (VDR), receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) in human periodontal ligament cells (hPDLC) populations and to analyze the potential mechanisms.


METHODS
Twelve hPDLC populations were primarily established from 12 donors individually. Two samples of each hPDLC population of passage three were treated respectively with 10(-8) mol/L VD(3) (V D(3) group) or 0.1% absolute ethyl alcohol as controls (control group). Six days later, the mRNA expression levels of VDR, RANKL and OPG in the samples were determined with real-time quantitative RT-PCR. The DNA base sequences upstream to the transcription start site of RANKL gene were also analyzed.


RESULTS
Compared with the control group, the mRNA expression level of VDR increased significantly in the VD(3) group (P = 0.003), averagely (3.04 +/- 1.06) times of that in the control group; the mRNA expression level of RANKL was also up-regulated by VD(3) (P = 0.001), 9.82 (0.75-119.18) times of that in the control group; the OPG expression level was (94.48 +/- 39.15)% of the controls (P = 0.136); OPG/RANKL ratio was down-regulated in the VD(3) group to averagely 10.36% (1.01%-138.00%) of the controls (P = 0.003). No mutation was found in the DNA fragments upstream to the transcription start site in the RANKL gene and the genotypes of the polymorphism at -1832 (rs7984870, C/G) were not shown to be significantly related to the RANKL mRNA expression level.


CONCLUSIONS
In hPDLC, VD(3) can significantly increase the mRNA expression level of VDR; VD(3) can increase RANKL mRNA expression level to decrease OPG/RANKL ratio, but it has little effect on OPG mRNA expression. The big differences of the RANKL mRNA regulation in response to VD(3) treatment among hPDLC populations may not be associated with the DNA sequences upstream to the transcription start site in the RANKL gene.
Tang
Xiao-Lin
XL
Department of Periodontology, Peking University School and Hospital of Stomatology, Beijing, China.
Meng
Huan-Xin
HX
Zhang
Li
L
D000293:Adolescent; D002117:Calcitriol / Q000494:pharmacology*; D002478:Cells, Cultured; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008297:Male; D053244:Osteoprotegerin / Q000378:metabolism*; D010513:Periodontal Ligament / Q000187:drug effects* / Q000378:metabolism; D053245:RANK Ligand / Q000378:metabolism*; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000378:metabolism; D018167:Receptors, Calcitriol / Q000378:metabolism*; D015854:Up-Regulation; D055815:Young Adult
D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018167:Receptors, Calcitriol; C506030:TNFRSF11B protein, human; C505688:TNFSF11 protein, human; D002117:Calcitriol