Vitamin D inhibits the expression of interleukin-8 in human periodontal ligament cells stimulated with Porphyromonas gingivalis.
OBJECTIVE
Vitamin D has been known to be closely associated with periodontitis while the exact mechanisms remain unclear. The present study aimed to discover the effects of 1a,25-dihydroxyvitamin D3 (1,25D) on the expressions of interleukin (IL)-6 and IL-8 in human periodontal ligament cells (hPDLCs) stimulated with Porphyromonas gingivalis (P. gingivalis) W83.


METHODS
Primary cultures of hPDLCs from ten donors were established and the cells of passage four were treated with 1,25D or P. gingivalis individually or 1,25D combined with P. gingivalis. The levels of IL-6 and IL-8 protein in hPDLCs were detected with enzyme-linked immunosorbent assay (ELISA) and the mRNA levels were detected with real-time RT-PCR.


RESULTS
P. gingivalis significantly promoted the protein expressions of IL-6 and IL-8. P. gingivalis at the multiplicity of infection (MOI) 100 exerted the strongest promotion effect on the IL-6 protein expression by 5.83-fold compared with the controls (2482.88±26.53pg/ml versus 425.80±77.25pg/ml, P<0.0005) and the IL-8 protein expression by 12.39-fold (4965.81±1072.55pg/ml versus 400.75±2.27pg/ml, P=0.005) in hPDLCs at 24h. At 48h, 10(-8)mol/L 1,25D had the best inhibition on the IL-8 protein expression in hPDLCs by 2.00-fold compared with the controls (100.76±21.11pg/ml versus 201.75±18.15pg/ml, P<0.0005) and the IL-8 mRNA expression by 2.13-fold (P<0.0005). 10(-8)mol/L 1,25D combined with P. gingivalis (MOI 100) exerted the strongest inhibition effect on the IL-8 protein expression by 1.54-fold compared with P. gingivalis treatment alone (3077.33±210.04pg/ml versus 4738.24±1386.17pg/ml, P=0.018) and the IL-8 mRNA expression by 1.78-fold (P=0.012) in hPDLCs at 12h. 1,25D did not influence the expression of IL-6 in hPDLCs with or without P. gingivalis treatment.


CONCLUSIONS
Vitamin D may potentially inhibit the periodontal inflammation induced by P. gingivalis partly by decreasing the IL-8 expression in hPDLCs.
Department of Medical Genetics, China Medical University, 92 North 2nd Road, Heping District, Shenyang, Liaoning Province, China.
Xiaolin
X
Tang
Yaping
Y
Pan
Yanyan
Y
Zhao
D000293:Adolescent; D000704:Analysis of Variance; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D016209:Interleukin-8 / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010513:Periodontal Ligament / Q000166:cytology / Q000378:metabolism*; D010518:Periodontitis / Q000188:drug therapy* / Q000378:metabolism; D016966:Porphyromonas gingivalis / Q000187:drug effects*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014807:Vitamin D / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D014815:Vitamins / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D055815:Young Adult
D015850:Interleukin-6; D016209:Interleukin-8; D012333:RNA, Messenger; D014815:Vitamins; D014807:Vitamin D