S100, bcl2 and myeloperoxid protein expirations during periodontal inflammation

Bacterial infections are the most important etiologic agents involved in acute and chronic periodontitis, it is multifactorial disease that leads to the destruction of the bone periodontium [1]. Inflammatory cells infiltration has been resulted from periodontal plasma cells: neutrophil, T- & B- lymphocytes and macrophages [2]. Periodontal lesions have been characterized by a persistence of infiltrating inflammatory cells, which may be responsible for the bone collagens resorcinol. Research by Baelum V. & Lopez R. [3] demonstrated that periodontal disease affects between 10 % and 15 % of the world’s population, being the greatest cause of tooth loss.

Inflammatory cells (plasma cells) have expressed in myeloperoxidase. Polymorphonuclear neutrophils are largely expressed the myeloperoxidase in plasma cells [4]. The myeloperoxidase gene is located on chromosome 17 (17q23.1) [5].

Myeloperoxidase (MPO) have catalyzed the synthesis of microbicidal hypochlorous acid enabling the defence against bacteria [6]. Furthermore, plasma cells synthesize hypochlorous acid from H₂O₂ and NaCl. Hydroxyl radical (−OH) is mostly active in damaging important molecules such as DNA proteins and lipids [7]. Hydrogen peroxide (H₂O₂) being a potent agent of oxygen species, is capable of crossing the nuclear membrane and damaging the DNA. [8] There is growing support for the claim that inflammation induces DNA damage which leads to apoptosis in periodontal cells [9] Furthermore, the apoptotic stimuli can trigger apoptosis via different mechanisms, including specific cell death receptors and ligands, such as cd95 [10], stress signals, inducing molecules directly or indirectly in apoptosis, via p53. Bcl2 is a member of anti-apoptotic family proteins that can prevent or reduce cell death induced by a variety of stimuli [11]. The BCL-2 gene was identified in the chromosome human t(14;18) [12]. The intrinsic death pathway is initiated by the mitochondrial release of cytochrome c, a process that is inhibited by anti-apoptotic bcl2 proteins [13].

S100 proteins have expressed in the neutrophils cytosol, monocytes, activated macrophages, and keratinocytes and released during activation or death of these cells. The S100 gene family includes at least 13 members that locate as a cluster on chromosome 1q21 [14]. s100 proteins also known as L1 antigens, calgranulin A and B, macrophage migration inhibitory, factor-related protein (MRP) and cystic fibrosis antigen, have several functions in inflammatory reactions [15].

The results by Sun-Hee Heo et. al. [16] have shown the expression patterns of S100A2 in gingival tissues during bacterial lipopolysaccharide stimulation. S100A2 expression was upregulated by bacterial lipopolysaccharide.

We have hypothesis states that there is the relationship between the s100, bcl2 and myeloperoxidase in gingival tissues (MPO does affect the level of s100, bcl2).

The aim of this study is to compare the expression levels of s100, bcl2 and MPO in gingival tissues on different stages of periodontal disease and compared to the giant-cell epulis.

The groups 1 and 2 of men and women consisted mostly age range 30- to 70-years. Group 1 giant cells occurred in the lower jaw (55 %) more frequently than in the upper jaw. In the group 2 the patients have been divided into 13 with acute and 17 with chronic inflammations.

In Fig. 1a A we observed low-size cell infiltration in acute inflammation. Significant cell infiltration and proliferating epithelium (Fig. 1b) appeared to be more intensive in the chronic inflammation. Acute and chronic inflammatory cells are circulating leukocytes, plasma cells and tissue macrophages.

Peripheral giant cell epulis is shown in Fig. 1c Microscopic examination has revealed the tissue with the abundance of giant-cells (Fig. 1c F), fibrous connective tissue, areas of haemorrhages (Fig. 1c E) and few capillaries. There was no sign of malignancy. Chronic inflammation when the macrophages fail to disintegrated various particles, fuse together and form multinucleated giant cells. Besides, morphologically distinct giant cells also appear in some tumours also.

S100, Bcl2 and MPO expressed in giant-cells. S100 expression, bcl2 expression and myeloperoxidase expression in giant-cells epulis are shown in Fig. 2. By immunohistochemistry, 100 % of giant-cells appeared to be positive for myeloperoxidase, whereas only 75,31 % of giant-cells were positive for Bcl 2 (P < 0.05). By the fact s100 protein has expressed in 10,72 % of giant-cells. Myeloperoxidase has physiologically expressed in plasmatic cells of epulis 87,69 %. s100 and bcl 2 have expressed in plasmatic cells 24,34 % (P < 0.05) and 11,28 % respectively, bcl 2 and myeloperoxidase expression being weak or absent in the connective tissue.

The immunoexpression of s100, bcl2 end MPO (Group 2) have been confirmed by the presence of brown stained cytoplasm in cell infiltration. In general, s100 staining was more intensive in the plasmatic cells. In acute inflamation S100 (Fig. 2) only 36,2 ± 5,3 % of the cells appeared to be positive. The cell infiltration, showed bcl2 immunoreactivity figured 76,1 ± 3,3 % (P < 0.05) in acute process (Fig. 2). Myeloperoxidase has expressed in 98,2 ± 5,9 % (P < 0.01) positive cells in acute inflammation.

Figure 2 shows the results of the s100, bcl2 and MPO expression in chronic process.

Myeloperoxidase 82,28 ± 2,5 % P < 0.01 was expressed in chronic plasmatic cell infiltration during inflammation. Bcl 2 was expressed in chronic plasmatic cells infiltration 55,67 ± 6,1 % P < 0.05. Тhe immunoexpression of S100 in cell infiltration has shown the result of 95,0 ± 0.31 % positive cells.

Тhe immunoexpression of s100, bcl2 and MPO in epithelial layers (acute process) have shown the result of 100 %, 82,2 ± 2.93 % and 100 % respectively. In chronic process of inflammation the positive cells have demonstratrd s100 - 100 %, bcl2 – 78,25 ± 4,23 % and myeloperoxidase - 100 % respectively.

This study has claimed that MPO was able to stimulate higher of bcl2 expression in inflammation cells during chronic and acute process. Myeloperoxidase activity expressed in neutrophils recruited to the gingiva after chemical or immunological insults contributes to tissue destruction. Meloperoxidase might influence the extent and/or the severity of periodontal diseases [17].

High level of the MPO have been observed in giant cells. Elevated bcl2 expression levels can prevent cellular apoptosis, thereby inducing inflammatory cells to remain locally in the periodontal tissue, causing consequent excessive cytokine secretion which leads to the progressive destruction of periodontal tissues [1]. Myeloperoxidase can be liberated from activated neutrophils by degranulation only in moderate levels [18], and bcl2 availability protects regions. Cytolysis of neutrophils in the course of inflammation formation could provide a release mechanism [18, 19] and explain the high levels of myeloperoxidase and S100. Activity of S100A12 and C-reactive protein can be markers of inflammatory activity in chronic periodontitis [20]. Previous studies have suggested that apoptosis is involved in the pathogenesis of inflammatory periodontal disease [21]. It has also been demonstrated that the higher frequency of Bcl-2 expression results in progressive periodontal destruction [22].

Gamonall et all. [23] has not found statistical difference in varions amount of bcl2 in healthy gingiva and in gingiva of patients with periodontal disease. Our studies have confirmed the view of Pandilova [24] and Ellis et all. [25] that chronic progression of inflammation decrease expresses bcl-2. In human gingival fibroblasts with inflammation activation of bcl2 has not been observed in different stages of the infection and giant-cell epulis. Sule Bulut et all. [26] results indicate that the pathogenesis of cyclosporin A induced gingival overgrowth might involve inhibition of apoptosis and overexpression of bcl-2 in the setting of high serum cyclosporin A. Our study has demonstrated a high level of bcl2 expression and inhibition of apoptosis in cells of gingival epithelium. We believe this is due to the epithelium protective functions. In gingival epithelium s100 is also related to the differentiation stage [27]. These positive cells are known to activate macrophages or neutrophils [28]. Research by Saito et al. [29] demonstrated numerous bcl-2-positive epithelial cells in gingival biopsies from patients who were taking nifedipine and phenytoin, indicating that this protein might be involved in the development of nifedipine-induced gingival hyperplasia. We believe that the presence of Bcl-2 protein is not an indicator of giant cell epulis favorable courses.

S100 plays a important part in the immune response related to periodontitis. s100 binds 2 Ca2+ and 2 Zn2+ ions. If Zn2+ binds to S100 it decreases its Ca2+ affinity. S100 also interacts with p53 in a Ca2 + −dependent manner, which affects stability of S100-p53 interaction [30] Aforesaid s100-p53 interaction leads to inhibition of apoptosis during inflammation. The Bcl-2 protein is a potent inhibitor of cell death, whereas the wild-type p53 protein activates the apoptotic pathway [5].

Mutated p53 loses this function and allows the proliferation of neoplastic cells. Bcl-2 also modulates the function of p53 and triggers cell proliferation and transformation [31].

Thr expression of S100 have been detected as proinflammatory phagocytes cells at sites of intestinal inflammation [32, 33]. Systemic autoimmune diseases (dermatomyositis, systemic lupus erythematosus, Kawasaki disease etc.) have clear association with S100 expression in macrophages infiltraton with degeneration of tissue [34, 35].

Investigations on bcl2 marker in gingival cells during periodontal inflammation we suggestion that periodontium tissues, continuously exposed to bacterial infections may contain cells with high level of myeloperoxidase results that damage DNA by product of catalysis.

The highest levels of s100 activity have been found at sites with chronic inflammation. Our results suggest that low s100 expression may play an important role in the activity of giant cells in giant cell epulis. That is considered to be the most significant factors of prognosis in giant cell granuloma. As a result of our research we created a diagram Fig. 3.