Profiling gingival crevicular fluid from smoking and non-smoking chronic periodontitis patients

BACKGROUND

Smoking is a major risk factor for the development and progression of chronic periodontitis (CP). Gingival crevicular fluid (GCF) derived from these patients contains many proteins that could serve as important diagnostic indicators. A protein chip technology called Surface Enhanced Laser Desorption/Ionization-Time of Flight-Mass Spectrometry (SELDI-TOF-MS) has recently been developed to facilitate protein profiling of complex biological mixtures. The hypothesis to be tested was SELDI-TOF-MS could distinguish between GCF of CP patients by smoking status and pocket depth.

METHODS

GCF samples collected before treatment from sixteen CP patients (eight smokers and eight non-smokers) at both shallow and deep sites were evaluated by SELDI-TOF-MS. Spectral fingerprints were constructed for both cohorts and analyzed by a two-way ANOVA according to smoking status and pocket depth. Significance threshold was set at p < 0.05. Mean molecular weight (MW) peaks and intensities were also analyzed.

RESULTS

The spectral fingerprints were significantly different between the two cohorts when analyzed by ANOVA according to smoking status (p < 0.0001) but not pocket depth (p = 0.9876). Also, the mean intensity of many individual MW peaks were determined to be significantly different between the two cohorts. Several peaks ranging in MW from 11-14 kDa were only detected in the GCF obtained from smokers.

CONCLUSIONS

This study has demonstrated that profiling of GCF by SELDI-TOF-MS can distinguish between CP smokers and non-smokers. Moreover, over-expressed proteins in GCF from smokers may serve as biomarkers for this high risk patient population.

Regulation of cytokine production in human gingival fibroblasts following treatment with nicotine and lipopolysaccharide

BACKGROUND

Patients who smoke are at increased risk for chronic periodontitis (CP). Most studies suggest that the microbial flora in these patients is similar to that found in non-smoking CP patients. Thus, the increased risk for development of CP is not dependent on an altered microbial profile, but rather to some change in the host response to these periopathogens. There is evidence that human gingival fibroblasts (HGF) derived from diseased sites produce greater amounts of interleukin (IL)-6 and IL-8 in vitro than cells derived from healthy sites. This suggests that HGF subpopulations may be selected based upon the inflammatory milieu in which they reside. The hypothesis to be tested was that the combination of nicotine and lipopolysaccharide (LPS) could regulate HGF inflammatory mediator production.

METHODS

HGF cell cultures were established from explants derived from 10 patients with CP. HGF cell cultures were stimulated with 1 mM, 1 microM, or 1 nM nicotine +/- Escherichia coli or Porphyromonas gingivalis LPS. At 12, 24, or 48-hour time points, the cells were counted and the supernatant was collected for subsequent IL-6 and IL-8 determination in an enzyme-linked immunosorbent assay.

RESULTS

At the 24-hour time point, 1 nM nicotine stimulated IL-6 production compared to control (P=0.02). E. coli LPS alone caused a 3- to 4-fold increase in IL-6 and IL-8 production, whereas P gingivalis LPS did not augment IL-6 or IL-8. A synergistic effect upregulating IL-6 was observed with combined treatment of 1 mM nicotine and E. coli LPS or P gingivalis LPS at the 24-hour time point (P<0.0005 and P=0.002, respectively). Similar effects were seen when IL-8 production was evaluated following HGF stimulation with high doses of nicotine and E. coli LPS or P gingivalis LPS.

CONCLUSIONS

These results demonstrate that nicotine by itself can stimulate HGF IL-6 and IL-8 production. Moreover, the combination of high doses of nicotine and either E. coli or P gingivalis LPS can synergistically upregulate cytokine production. These findings support the hypothesis that a proinflammatory fibroblast phenotype may be elicited in an environment enriched with bacterial LPS and nicotine.