Increased and correlated expression of connective tissue growth factor and transforming growth factor beta 1 in surgically removed periodontal tissues with chronic periodontitis.

BACKGROUND AND OBJECTIVE: Both gingival tissue destruction and regeneration are associated with chronic periodontitis, although the former overwhelms the latter. Studies have shown that transforming growth factor beta 1 (TGF-ß1), a growth factor largely involved in tissue regeneration and remodeling, is upregulated in chronic periodontitis. However, the gingival expression of connective tissue growth factor (CTGF or CCN2), a TGF-ß1-upregulated gene, in patients with periodontitis remains undetermined. Although both CTGF/CCN2 and TGF-b1 increase the production of extracellular matrix, they have many different biological functions. Therefore, it is important to delineate the impact of periodontitis on gingival CTGF/CCN2 expression. MATERIAL AND METHODS: Periodontal tissue specimens were collected from seven individuals without periodontitis (group 1) and from 14 with periodontitis (group 2). The expression of CTGF and TGFß1 mRNAs were quantified using real-time PCR. RESULTS: Analysis using the nonparametric Mann-Whitney U-test showed that the levels of expression of both CTGF/CCN2 and TGFß1 mRNAs were significantly increased in individuals with periodontitis compared with individuals without periodontitis. Furthermore, analysis using a nonparametric correlation (Spearman r) test showed a positive correlation between TGFß1 and CTGF/CCN2 mRNAs. CONCLUSION: The gingival expression levels of CTGF/CCN2 and TGFß1 mRNAs in individuals with periodontitis are upregulated and correlated.

A trend of increase in periodontal interleukin-6 expression across patients with neither diabetes nor periodontal disease, patients with periodontal disease alone, and patients with both diseases.

BACKGROUND AND OBJECTIVE: Epidemiological studies have established that patients with diabetes have increased prevalence and severity of periodontal disease. However, the periodontal expression of inflammatory cytokines and matrix metalloproteinases (MMPs) in diabetic patients has not been well characterized. The objective of this study was to determine the difference in the periodontal expression of MMP-1, MMP-8, interleukin-6, tumor necrosis factor-alpha and interleukin-1beta between diabetic and nondiabetic patients. MATERIAL AND METHODS: Periodontal tissue specimens were collected from nine nondiabetic patients without periodontal disease (group 1), from 11 nondiabetic patients with periodontal disease (group 2) and from seven diabetic patients with periodontal disease (group 3). The expression of MMP-1, MMP-8, interleukin-6, tumor necrosis factor-alpha and interleukin-1beta was quantified using real-time polymerase chain reaction. RESULTS: The nonparametric Kruskal-Wallis test showed that the difference in interleukin-6 expression among the groups was statistically significant (p = 0.04). Furthermore, the generalized Kruskal-Wallis nonparametric linear-by-linear association test showed a statistically significant trend of increase in the expression of interleukin-6 from group 1 to group 2 to group 3 (p = 0.02) and a suggestion of such a trend for MMP-1 (p = 0.05). No increase in MMP-8 expression was observed in patients in group 3 compared to patients in groups 1 and 2. Although the average expression levels of MMP-1, interleukin-1beta and tumor necrosis factor-alpha were increased from group 1 to group 3, the differences were not statistically significant. CONCLUSION: A trend of increased interleukin-6 expression in periodontal tissues was observed across patients with neither diabetes nor periodontal disease, patients with periodontal disease alone, and patients with both diseases.