Correlative Study Between The Expression Of Caspase-3,8 And Apoptosis In Gingival Tissues With Chronic Periodontitis

Objective:To study the apoptosis of the gingival tissues in chronic periodontitis and analysis the expression and the significance of the Caspase-3,8 in gingival tissues of chronic periodontitis and to investigate the relationship between the expression of them and the apoptosis. The aim is to further reveal the pathogenesis of chronic periodontitis and mechanism of its related tissue damage, which establish new diagnostic and treatment strategy as to provide a theoretical basis and experimental evidence.Methods:The occurrence of apoptosis and morphological changes were observed by HE staining using ordinary optical microscope in paraffin sections of 23 gingival tissues with chronic periodontitis and 23 healthy gingival tissues. Combine with transmission electron microscopy to observe ultrastructure of apoptotic cells and apply TUNEL method to detect apoptosis and the apoptosis index (AI) in chronic periodontitis and normal gingival tissues. Meanwhile, the expression and distribution of Caspase-3 and Caspase-8 were detected by immunohistochemical staining SP method. The experimental results used by SPSS16.0 staristical software for statistical analysis. To analysis the apoptotic index and the average optical density and the average gray value of Caspase-3 and Caspase-8. And the correlation between the Caspase-3,8 and apoptosis in chronic periodontitis gingival tissue and its relationship were evaluated.Results:1. Compared with the normal group, the occurrence of apoptosis characteristic morphological changes were found more significant in gingival tissues of chronicperiodontitis.2. Detection of apoptotic index by TUNELGingival tissue of chronic periodontitis group shows a large number of apoptotic cells, and shows occasionally a small amount of apoptotic cells in normal control group. The AI(0.419±0.09) in gingival tissue of chronic periodontitis, is significantly higher than the control group(0.058±0.05) (P<0.05).3. Detection of the espression and distribution of Caspase-3 by immunohistochemical staining SP methodOnly a small amount of Caspase-3 positive cells were expressed. The average optical density of Caspase-3 in gingival tissues of chronic periodontitis(0.56±0.06), is significantly higher than the control group(0.29±0.02)(t=19.510, P<0.05); the average gray value(75.81±10.69), is significantly lower than the control group(128.41±4.45)(t=-20.387, P<0.05). Compared with the normal group, the expression of the Caspase-3 in gingival tissues of chronic periodontitis was obviously enhanced (P<0.05).4. Detection of the espression and distribution of Caspase-8 by immunohistochemical staining SP methodOnly a small amount of Caspase-8 positive cells were expressed. The average optical density of Caspase-8 in gingival tissues of chronic periodontitis(0.36±0.02), is significantly higher than the control group(0.29±0.01)(t=16.381, P<0.05); the average gray value(110.69±4.18), is significantly lower than the control group(131.75±3.39)(t=-17.673, P<0.05). Compared with the normal group, the expression of the Caspase-8 in gingival tissues of chronic periodontitis was obviously enhanced (P<0.05).5. The relationship between the expression of Caspase-3,8 and apoptosis in gingival tissues of chronic periodontitisThe positive expression of Caspase-3,8 in gingival tissues of chronic periodontitis are correlated with AI had positive correlation, and between the groups is statistically significant(P<0.05).6. The inter-relationship between the expression of Caspase-3 and Caspase-8 in chronic periodontitisStatistical analysis shows that the positive expression of Caspase-3 and Caspase-8 is unrelated. The comparison of the average optical density is (r=0.173, p=0.479, P>0.05), and the comparison of the average gray value is(r=0.407,P=0.054, P>0.05).Conclusions:1. Apoptosis significangly increase in gingival tissues of chronic periodontitis, suggesting that abnormal apoptosis has a certain relationship with the occurrence of the chronic periodontitis.2. Apoptosis relate protein Caspase-3 and Caspase-8 in gingival tissues of chronic periodontitis are positive expressed, and positive correlation with the AI, suggesting that Caspase-3 and Caspase-8 are closely related with apoptosis of gingival tissues cells of chronic periodontitis. Both death receptor-mediated apoptosis pathway may be involved in the pathogenesis of chronic periodontitis.3. The expression of Caspase-3 and Caspase-8 is unrelated, suggesting that in the signal transduction pathway of apoptosis, in addition Caspase-8 death receptor-mediated signal transduction pathway activate Caspase-3, it may also exist other apoptosis pathway.