Profile of Cytokine mRNA Expression in Chronic Adult Periodontitis

Abstract

Chronic inflammation induced by bacteria often leads to host-mediated destruction of tissues adjacent to the sites of microbial insult. The chronic inflammatory process of adult periodontitis results in the destruction of supporting osseous and connective tissues of the teeth. We hypothesized that virulence factors of periodontal pathogens such as lipopolysaccharide stimulate inflammatory cytokine expression by mononuclear cells of the host which contribute to disease development. In this study, to elucidate the role of these cytokines in chronic adult periodontitis, we tested whether the prevalence of mRNA for inflammatory cytokines generally associated with mononuclear phagocytes was higher in diseased than in healthy gingival tissue. Gingival mononuclear cells or whole gingival biopsies from 32 adult periodontitis patients and five healthy individuals used as controls were evaluated for inflammatory cytokine mRNA expression by reverse-transcription polymerase chain-reaction (RT-PCR) procedures. The cytokines assessed included IL-1 alpha, IL-1 beta, IL-1ra, IL-6, IL-8, IL-12, IL-13, TNF-alpha, TGF-beta, and IFN-gamma. The monocyte/macrophage lipopolysaccharide (LPS) receptor CD14 was also assessed. Results showed that TNF-alpha mRNA was present significantly more frequently in diseased than in healthy biopsies, whereas IL-1 alpha, IL-1 beta, and IL-1ra mRNA were found in most (from 80 to 100%) healthy tissues. Message for CD14 was present in both healthy and diseased tissue samples (100%). This study provides evidence for a major role of TNF-alpha in chronic adult periodontitis. Moreover, our results suggest that the mononuclear cells derived from periodontal tissues have the capacity to respond to components of periodontal pathogens and express both pro- and anti-inflammatory cytokines in these tissues.

MiR-17 Modulates Osteogenic Differentiation Through a Coherent Feed-Forward Loop in Mesenchymal Stem Cells Isolated from Periodontal Ligaments of Patients with Periodontitis

“…A thorough and deep research of the differences including the difference of genes related to inflammation between H-PDLSC and P-PDLSC is going to be one of interesting research direction. Furthermore, several studies indicated that the expression of IL-1b and TNF-a is higher in diseased periodontal tissue than in healthy periodontal tissue [24][25][26][27][28]. We also found that the expression levels of both inflammatory cytokines were significantly higher in P-PDLSCs by 6.1-and 2.3-fold, respectively, relative to H-PDLSCs (data not shown).…”

“…There are a lot of inflammatory cytokines involved in pathology of periodontitis such as IL-1b, TNF-a, IL-6, IL-8, matrix metallo proteinase, monocyte chemotactic protein-1, and so on [25,26,28]. However, for the purpose of this experiment, we have focused on two major inflammatory cytokines in microenviroment of periodontitis, IL-1b and TNF-a [40].…”

“…As a key negative regulator in osteoblast differentiation, elevated TNF-a has been shown to induce bone loss through upregulation of Smurf1 levels [58]. In microenvironments of choric periodontitis, compared to healthy sites, local TNF-a levels have been found to be significantly elevated and are associated with periodontal tissue destruction [24][25][26][27][28]40]. Consistently, excessive inflammatory cytokines levels, which are induced directly, target Smurf1 expression, indicating that osteoblast inhibitory signals are dominant over the inhibition of osteogenic differentiation potential in PDLSCs.…”

“…Several studies showed that the expression levels of two major inflammatory cytokines of periodontitis, Interleukin (IL)-1b and TNF-a, were significantly higher in periodontal diseases [24][25][26][27][28]. To confirm whether inflammatory cytokines affect miR-17 and Smurf1 expression during osteoblast differentiation, H-PDLSCs were cultured in osteoblast differentiation medium in the presence or absence of IL-1b (1 ng/ ml) or TNF-a (10 ng/ml) for 7 days.…”

Osteoblast and Gingival Fibroblast Markers in Dental Implant Studies

“…TNF-α is a potent osteoclastogenesis agent secreted by various cells, gingival fibroblasts and fibroblasts of the periodontal ligament [88][89][90] . It has been implicated in the bone loss and connective tissue destruction associated with periodontal disease 88,91,92 .…”