Expression of Toll­like receptor 4 on mast cells in gingival tissues of human chronic periodontitis.

The purpose of the present study was to examine the expression of Toll­like receptor 4 (TLR4) on mast cells in gingival tissues of human chronic periodontitis. A total of 68 donors, including 23 with mild chronic periodontitis, 25 with advanced chronic periodontitis and 20 healthy controls, were included in the present study. Gingival specimens from the donors were fixed in 4% neutral formalin, stained with hematoxylin and eosin for histologic observation, stained for immunohistochemical identification of TLR4 in gingival tissues, and stained with double immunofluorescence for the identification of TLR4 on mast cells in gingival tissues. The results revealed that the expression of TLR4 in the gingival tissues and on mast cells in the gingival tissues of patients with chronic periodontitis were significantly higher, compared with those of the normal control group (P<0.05). The expression levels of TLR4 in the gingival tissues and on mast cells in patients with advanced chronic periodontitis were significantly higher, compared with those in patients with mild chronic periodontitis (P<0.05). In conclusion, the expression of TLR4 in gingival tissues and on mast cells increased with the severity of chronic periodontitis, suggesting that TLR4, particularly mast cell TLR4, may be important in the disease process of human chronic periodontitis.

Tryptase and TIM-1 double-positive mast cells in different stages of human chronic periodontitis.

BACKGROUND/PURPOSE: Mast cells (MCs) play a critical role in the pathogenesis of allergic reactions and inflammatory conditions through the release of inflammatory mediators. T cell immunoglobulin mucin domain (TIM-1) has been reported to express in MCs. The aim of the present study was to examine the expression and analyze the quantification of TIM-1 on tryptase-positive MCs in different stages of human chronic periodontitis using double-immunofluorescence staining. MATERIALS AND METHODS: Individuals who participated in this study were divided into three groups: healthy control gingivae (n = 27), chronic slight periodontitis (n = 34), and chronic severe periodontitis (n = 31). Their gingival specimens were taken and fixed in 10% buffered formalin, stained with hematoxylin and eosin (HE) for histopathology, and stained with double-immunofluorescence (DIF) for identification of tryptase-TIM-1 double-positive MCs in gingival tissues. RESULTS: Compared with healthy controls, the densities (cells/mm2) of tryptase-TIM-1 double-positive MCs were significantly increased in both the chronic slight periodontitis (P < 0.05) and severe periodontitis groups (P < 0.01). However, compared with the chronic slight periodontitis group, both the score of gingival tissue inflammation and the density of tryptase-TIM-1 double-positive MCs in gingival tissue were significantly increased in the severe periodontitis groups (P < 0.05). Conclusion: By incorporating HE with double-immunofluorescence staining in human chronic periodontitis, the significantly increased number of tryptase-TIM-1 double-positive MCs had the similar tendency as the severity of periodontitis inflammation. Based on our results, we suggest that tryptase-TIM-1 double-positive MCs may play an important role in human chronic periodontitis.

Expression of matrix metalloproteinase-8 and matrix metalloproteinase-13 in mast cells of human periapical lesions.

OBJECTIVE: This study aimed to detect the expression of matrix metalloproteinase-8 (MMP-8) and MMP-13 in mast cells (MCs) of human periapical lesions and to discuss the pathogenic role of MCs in periapical lesions. METHODS: Ninety samples were divided into three groups: (1) periapical granuloma group (n=30); (2) periapical cyst group (n=30); (3) normal periodontal membrane group (n=30). The samples were fixed in 10% neutral formalin for over 48 h and made into serial sections. After H&E staining, histological changes were observed under the optical microscope. Moreover, double immunofluorescence (DIF) staining was performed to detect expression of MMP-8 and MMP-13 in MCs of periapical lesions under the fluorescence microscope. RESULTS: Compared with the normal control group, the number of MMP-8 and MMP-13 double positive MCs in the periapical lesions increased significantly (P<0.01). There was no significant difference in the density of MMP-8 and MMP-13 double positive MCs in the periapical cyst group and periapical granuloma group (P>0.05). CONCLUSION: The number of MCs increased significantly in periapical lesions and there was a considerable increase in the density of MMP-8 and MMP-13 double positive MCs. These results indicate that MCs positive for MMP-8 and MMP-13 might contribute to the pathogenesis of chronic apical periodontitis.

Immunomodulatory activity of interleukin-27 in human chronic periapical diseases.

This study aims to observe expression of IL-27 on different cells in periapical tissues of different types of human chronic periapical diseases. Periapical tissue specimens of 60 donors, including healthy control (n=20), periapical granuloma group (n=20) and radicular cysts group (n=20), were fixed in 10% buffered formalin, stained with hematoxylin and eosin for histopathology. Then specimens were stained with double- immuno-fluorescence assay for identification of IL-27-tryptase (mast cells, MCs), IL-27-CD14 (mononuclear phagocyte cells, MPs) and IL-27-CD31 (endothelial cells, ECs) double-positive cells in periapical tissues. The results indicated that compared with healthy control, the densities (cells/mm2) of IL-27-tryptase, IL-27-CD14 and IL-27-CD31 double-positive cells were significantly increased in human chronic periapical diseases (periapical granuloma group and radicular cysts group) (P<0.001). The density of IL-27-tryptase double positive cells in radicular cysts group was significantly higher than those in periapical granuloma group (P<0.001). Densities of IL-27-CD14 and IL-27-CD31 double-positive cells in periapical granuloma group had no significant difference with those in radicular cysts group (P=0.170 and 0.138, respectively). IL-27-CD14 double positive cells density achieved to peak among three cell groups in radicular cysts groups. In conclusion, IL-27 expressed in MCs, MPs and ECs of human chronic periapical diseases with different degrees. IL-27-tryptase double-positive cells may participate in pathogenic mechanism of chronic periapical diseases, especially for formation of fibrous in periapical cysts. IL-27-CD14 and IL-27-CD31 double-positive cells may participate in immunologic response to resist periapical infection, and they may play an dual role in pathogenesis and localization of periapical diseases.

Expression of transforming growth factor-ß in mast cells in human chronic periapical diseases.

This study was undertaken to investigate the distribution of mast cells (MCs) and the expression of transforming growth factor-ß (TGF-ß) on tryptase positive MCs in different types of human periapical diseases. Periapical tissues of 78 participates were used in this study, including healthy control (n=28), periapical cyst (n=25), and periapical granuloma (n=25). The tissue samples were fixed in 10% formalin for at least 48 h, followed by staining with hematoxylin and eosin (HE) for histopathological examination. Then, they were stained with toluidine blue for MCs and MCs degranulation examination, or stained with double immunofluorescence for identification of tryptase-TGF-ß double positive MCs. The results showed that the density of tryptase-TGF-ß double positive MCs in periapical lesions was significantly higher than that of healthy control (P<0.01). The number of TGF-ß positive MCs in the periapical cyst was potently higher than that in the periapical granuloma (P<0.01). In addition, compared with toluidine blue staining, the number of MCs with double immunofluorescence staining was significantly increased (P<0.01). The TGF-ß positive MCs may play an important role in the pathogenesis of human chronic periapical diseases, particularly in the formation of fibrous tissues in periapical cyst. Double immunofluorescence staining is more sensitive than the traditional toluidine blue staining for identifying MCs.

[Mechanical periodontal treatment combined with tetracycline for aggressive periodontitis].

OBJECTIVE: To evaluate the effect of mechanical periodontal treatment combined with tetracycline on periodontal attachment, distances of cementum-enamel junction (CEJ) to the bone defect bottom and to the alveolar crest, and avidity of serum IgG against Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS) in patients with aggressive periodontitis. METHODS: Twenty-six patients with aggressive periodontitis were divided equally into two groups to receive mechanical periodontal treatment combined with tetracycline or exclusive mechanical periodontal treatment, with another 20 periodontally healthy subjects serving as the control group. In the two patient groups, routine clinical examination of the subjects was performed to record periodontal attachment level and distances of CEJ to the bottom of the bone defects and to the alveolar crest before and 3 and 6 months after the treatment. The avidity of serum IgG against Pg LPS was measured by ELISA with thiocyanate elution before and after periodontal treatment. RESULTS: Compared with patients with exclusive mechanical periodontal treatment, patients with combined treatments showed significant improvement in periodontal attachment level and the distance of CEJ to the bone defect bottom after the treatment (P<0.01 and P<0.05, respectively) with also significantly reduced avidity of serum IgG against Pg LPS (P<0.01). CONCLUSION: Mechanical periodontal treatment combined with tetracycline produces favorable effects in patients with aggressive periodontitis.