Vitamin D-binding protein expression in healthy tooth and periodontium: an experimental study both in monkeys in vivo and in humans in vitro

Evaluation of serum and gingival crevicular fluid levels of Vitamin D binding protein in subjects with clinically healthy periodontium and chronic periodontitis: A clinico bio-chemical study

Background

Advances in oral and periodontal disease diagnostic research are moving towards methods wherein periodontal risk can be identified and quantified by objective measures such as bio-markers. Given the roles of vitamin D binding protein (DBP) in modulating the immune response and in the transport of vitamin D, it is hypothesised that quantitative changes of vitamin DBP are associated with periodontal disease.

Aim

The aim of the current study is to measure DBP levels in serum and gingival crevicular fluid (GCF) of patients with generalised chronic periodontitis, in comparison to healthy controls.

Materials and Methods

The present cross-sectional clinico-bio-chemical study includes 30 systemically healthy subjects with 15 periodontally healthy and 15 chronic periodontitis subjects who were recruited from the out-patient Department of Periodontics. GCF and blood samples were collected from all the patients. DBP estimation was performed in both the samples using a commercially available ELISA kit.

Results

Serum and GCF DBP levels in chronic periodontitis subjects were significantly higher when compared to the periodontally healthy group. There were no significant correlations found among serum and GCF DBP levels with gender and increasing age in both the groups. An increase in disease severity measured by the increase in probing pocket depth and clinical attachment loss did not show correlation with the GCF and serum DBP levels in the chronic periodontitis group.

Conclusion

Based on the findings of the present study, increased serum and GCF DBP levels in chronic periodontitis seem to be a probable marker for identifying ongoing periodontal destruction.

Association between Vitamin D Receptor Gene Polymorphisms and Periodontal Bacteria: A Clinical Pilot Study

Background: Periodontitis is an inflammatory disease caused by microorganisms involving the supporting tissues of the teeth. Gene variants may influence both the composition of the biofilm in the oral cavity and the host response. The objective of the study was to investigate the potential correlations between the disease susceptibility, the presence and the quantity of periodontopathogenic oral bacterial composition and the VDR gene polymorphisms. Methods: Fifty (50) unrelated periodontal patients and forty-one (41) healthy controls were selected for genomic DNA extraction. DNA concentration was measured and analyzed. The periodontopathogenic bacterial species were identified and quantified using a Real Time PCR performed with species-specific primers and probes. Results: Genotype distribution showed a different distribution between the groups for BsmI rs1544410 genotypes (p = 0.0001) with a prevalence of the G(b) allele in periodontal patients (p = 0.0003). Statistical significance was also found for VDR TaqI rs731236 (p ≤ 0.00001) with a prevalence of the T(T) allele in periodontal patients (p ≤ 0.00001). The average bacterial copy count for the periodontitis group was significantly higher than that of control group. Dividing patients into two groups based on high or low bacterial load, FokI rs2228570 T allele (f) was statistically more represented in patients with high bacterial load. Conclusions: The findings of the study suggest the involvement of the VDR gene BsmI and TaqI polymorphisms in periodontal disease, while FokI and BsmI may be involved in determining an increased presence of periodontopathogens.

Expression of vitamin D 1α-hydroxylase in human gingival fibroblasts in vivo

Background

Vitamin D 1α-hydroxylase CYP27B1 is the key factor in the vitamin D pathway. Previously, we analyzed the expression of CYP27B1 in human gingival fibroblasts in vitro. In the present study, we analyzed the gingival expression of CYP27B1 in vivo.

Methods

Forty-two patients with periodontitis Stage IV Grade C and 33 controls were recruited. All patients with periodontitis had unsalvageable teeth and part of the wall of the periodontal pocket was resected and obtained after tooth extraction. All controls needed crown-lengthening surgery, and samples of gingiva resected during surgery were also harvested. All the individuals' gingivae were used for immunohistochemistry and immunofluorescence. In addition, gingivae from seventeen subjects of the diseased group and twelve subjects of the control group were analyzed by real-time PCR.

Results

Expression of CYP27B1 was detected both in gingival epithelia and in gingival connective tissues, and the expression in connective tissues colocalized with vimentin, indicating that CYP27B1 protein is expressed in gingival fibroblasts. The expression of CYP27B1 mRNA in gingival connective tissues and the CYP27B1 staining scores in gingival fibroblasts in the diseased group were significantly higher than those in the control group.

Conclusions

Expression of CYP27B1 in human gingival tissues was detected, not only in the fibroblasts of gingival connective tissues, but also in the gingival epithelial cells, and might be positively correlated with periodontal inflammation.

Ferritin expression in the periodontal tissues of primates

Ferritin, an iron-binding protein, is composed of two subunits, ferritin heavy chain and ferritin light chain. It regulates many biological functions, such as proliferation, angiogenesis, and immunosuppression. The objective of this study was to determine the expression and distribution of ferritin in the periodontal tissues of primates. First, we assessed the expression of ferritin in primary cultured cells isolated from human periodontal tissues using the polymerase chain reaction and immunofluorescent staining in vitro. Second, we investigated the expression and distribution of ferritin in the periodontal tissues of Macaca fascicularis, human gingival tissues, and human gingival carcinoma tissues using immunohistochemistry in vivo. Both protein and mRNA of ferritin were constitutively present in human primary cultured cells, including those from the dental apical papilla, periodontal ligament, dental pulp, and gingival epithelium, as well as gingival fibroblasts. In M. fascicularis tissues, the immunohistochemical staining was particularly strong in blood vessel and mineralizing areas of the dental pulp and periodontal ligament. Ferritin heavy chain exhibited specific immunopositivity in the stratum basal of the epithelium in human gingival tissue, and strong immunostaining was found in peripheral regions of gingival carcinoma sites. Ferritin is constitutively present and widely distributed in the periodontal tissues of primates. Ferritin may play roles in epithelial proliferation, vascular angiogenesis, and mineralization in these tissues.

The relationship of 1,25-dihydroxyvitamin D and Vitamin D binding protein in periodontitis

OBJECTIVE

This study was conducted to explore the relationship between 1,25-dihydroxy vitamin D (1,25(OH)2D) and Vitamin-D binding protein (DBP) in patients with periodontitis and healthy controls.

METHODS

Seventy-five periodontitis cases were recruited from the dental OPD of Dow University of Health Sciences, Karachi. Diagnostic criteria of periodontitis were followed according to the probe pocket depth and clinical attachment loss. Seventy-five periodontal healthy controls were selected from the faculty and students of same university. Serum levels of 1,25(OH)2D and DBP were determined by ELISA.

RESULTS

Significantly low levels of 1,25(OH)2D and high levels of serum DBP were observed in periodontitis patients compared to healthy controls (p<0.05), with levels of DBP increasing significantly with the severity of periodontitis (p=0.005). Concentrations of DBP correlated positively with 1,25(OH)2D, especially in cases with periodontitis (r =0.780; p<0.001).

CONCLUSION

Within the limits of the study, we conclude that low 1,25(OH)2D levels and high DBP levels are associated with periodontitis.