Expression Of Cyt-C And Caspase-9 And Apoptosis In Gingival Tissues With Chronic Periodontitis

Objective:Chronic periodontitis is a common and frequently encountered disease, which is the main reason for adult tooth loss. More than 80% people have periodontal disease in China. The etiology of chronic periodontitis is complex. With the further research on cause of chronic periodontitis, it has been discovered that the pathogenesis of chronic periodontitis is closely related with apoptosis. Therefore, their relationship has become the topic of this research. The aim of our study was to observe the cell apoptosis of gingival tissues from chronic periodontitis patients and to explore the possible mechanisms of it, thus providing theoretical basis for the treatment of chronic periodontitis.Methods:The apoptotic cells and their ultrasturcture gingival tissues both from healthy individuals and from peridontitis patients were observed by hispathological examination and transmission electron microscopy, respectively. All tissues were analyzed for expression and distribution of Cyt-C and Caspase-9 in gingival tissues using immunohistochemical SP method. Besides, the apoptotic cell cycle was determined by flow cytometry analysis.Results:1. Histopathological examination (HE staining)In periodontitis group, spikes proliferated obviously, chronic inflammatory cells infiltrated in the lamina propria, and collagen fibers arranged irregularly. Besides, "apoptosis-like cell" also existed in gingival tissues of chronic periodontitis patients. In normal group, epithelial spikes were slender and serrated, inflammatory cells in the lamina propria were less than periodontitis group, and collagen fibers were arranged in neat bundles.2. Ultrastructure of apoptotic cellsIn periodontitis group, apoptotic cells existed mainly in the epithelium, and some of them could form "apoptotic bodies". The structure of organelles in normal group was intact and morphologically normal. No "apoptotic bodies" could be formed.3. Cell cycleIn peridontitis group, the subdiploid or sub-G1 peak which represents apoptosis cells was observed before normal diploid or G0/G1 peak on a DNA histogram. No such peak was observed in normal group.4. Expression and distribution of Cyt-C and Caspase-9In periodontitis group, the positive expression of Cyt-C and Caspase-9 protein was mainly in epithelium. The average optical density and the average gray value in periodontitis group were significantly different (P<0.05) with the normal group.Conclutions:Apoptosis cells can be observed in gingival tissues of chronic periodontitis patients. Compared with the normal group, the expression of Cyt-C and Caspase-9 in chronic periodontitis group mainly in the epithelium is significantly higher (P<0.05). Therefore, apoptosis exists in gingival tissues of chronic periodontitis, which is dependent on mitochondrial pathway.