Global burden of periodontal disease and its relation with socioeconomic development during 1990-2019 / 浙江大学学报·医学版

To analyze the global burden of periodontal disease and its relation with socioeconomic development. Data of global disability-adjusted life year (DALY) due to periodontal disease and human development index (HDI) from 1990 to 2019 were obtained from Global Health Data Exchange (GHDx) and human development reports. The trend of the global burden of periodontal disease from 1990 to 2019 was described. The correlation between age-standardized DALY rates and HDI were examined in 2019, and between-country periodontal disease burden inequality from 1990 to 2019 was measured using health-related Gini coefficients and concentration indexes. From 1990 to 2019, the global DALY rate due to periodontal disease increased from 78.63 to 85.48, and the epidemiological burden did not increase significantly. Statistical differences were found across different HDI categories for age-standardized DALY rates of periodontal disease ( 44.315, <0.01) in 2019. Linear regression analysis also revealed a negative correlation between age-standardized DALY rate of periodontal disease and HDI ( = -0.417, <0.01) . Gini coefficients decreased from 0.361 to 0.281 and concentration indexes fell from 0.0339 to -0.0538 between 1990 and 2019. The global burden of periodontal disease did not increase between 1990 and 2019, though the socioeconomic-associated inequality still existed. The burden of periodontal disease was more concentrated in less developed countries, and the socioeconomic-associated inequality has increased since 2000.

TRAF6/ERK/p38 pathway is involved in interleukin-17-mediated autophagy to promote osteoclast precursor cell differentiation / 浙江大学学报·医学版

To investigate the effects of interleukin (IL)-17-mediated autophagy on the TNF receptor associated factor (TRAF6)/extracellular signal-regulated kinase (ERK)/p38 pathway and osteoclast differentiation. Mouse bone marrow-derived macrophages (BMM) were cultured with a medium containing 30 ng/mL macrophage colony stimulating factor and 50 ng/mL receptor activator of nuclear factor-kappa B ligard (RANKL), and IL-17 (0.01, 0.1, 1.0, 10 ng/mL) was added for intervention (IL-17 group). Tartrate-resistant acid phosphatase (TRAP) staining was used to observe TRAP positive multinucleated cells; phalloidin fluorescent staining was used to detect actin ring circumference; toluidine blue staining was used to analyze bone resorption lacuna formation. To further examine the mechanism of the effect of IL-17-mediated autophagy on the differentiation of osteoclasts, the control group used RANKL medium to culture mouse macrophage RAW264.7 cells, while the IL-17 group was treated with IL-17 (0.01, 0.1, 1.0, /mL). Western blot was used to detect the expression of autophagy-related proteins Beclin-1, microtubule-associated protein 1 light chain 3 (LC3) and osteoclast-related proteins c-fos and nuclear factor of activated T cell 1 (NFATc1) after treatment with different concentrations of IL-17. The expression of LC3, NFATc1, TRAF6/ERK/p38 signaling pathway related proteins were detected in IL-17 and autophagy inhibitor 3-MA group. The number of TRAP positive multinucleated cells, the circumference of the actin ring and the area of bone resorption lacuna in IL-17 group treated with IL-17 (0.01, 0.1, were significantly higher than those in the control group. In IL-17 treated RAW264.7 cells, the expression of c-fos, NFATc1, Beclin-1, LC3, TRAF6, p-ERK, and p-p38 was all significantly up-regulated (all 0.05). After treatment with the autophagy inhibitor 3-MA, the expression levels of LC3, NFATc1, TRAF6, p-ERK, and p-p38 all decreased significantly (all 0.05). IL-17 can promote the expression of autophagy proteins and enhance the differentiation ability of osteoclast precursor cells, and the TRAF6/ERK/p38 signaling pathway may be involved in this process.

Research progress in secreting sytokines interferon-gamma and interleukin-17 of T helper 1 and 17 cells on periodontitis / 中华口腔医学杂志

Periodontal disease (PD) is an infection-driven chronic inflammatory disease characterized by the inflammation of tooth-supporting tissues and the destruction of the associated alveolar bone. The immune response of the host to periodontal pathogens infection determines the course and progress of the disease. The effects of secreting cytokines interferon-gamma (IFN-γ) and interleukin-17 (IL-17) of T helper 1 cells (Th1) and T helper 17 cells (Th17) on the development of periodontitis has attracted much attention. IFN-γ is a potential immune-modulatory cytokine and can mediate cellular immune responses by activating various immune cells of the host such as macrophages. As one of the most potential bone physiological regulation mediators, IL-17 is closely related with alveolar bone resorption in periodontitis. This review elaborated the relationship between IFN-γ and IL-17 in the progress of periodontitis, providing new explanations into the development of periodontitis and alveolar bone destruction caused by the host immune response.

Effects of T helper 1 cells and T helper 17 cells secreting cytokines on rat models of experimental periodontitis / 中华口腔医学杂志

Objectvie@#To investigate the effects of secreting cytokines interferon-gamma (IFN-γ) and interleukin-17 (IL-17) of T helper 1 cells (Th1) and T helper 17 cells (Th17) on the peripheral blood and alveolar bone destruction, so as to provide a new explanation for cellular immunity-mediated alveolar bone destruction.@*Methods@#Eighteen eight-week-old male Sprague-Dawley rats were divided, randomly and equally, into 3 groups: lipopolysaccharide (LPS) group, ligation group and normal control group. In the LPS group, Escherichia coli LPS was injected into the alveolar mucosa on the buccalmedian site of the left upper first molar, while the right upper first molar was injected with equal volume of physiological saline as self-controls. The injections were performed every other day for four times totally. In the ligation group, the left upper first molars were ligatured with 0.2 mm orthodontic cords, while the right upper first molars were left untreated as self-controls, and supplemented with high-sugar diet to promote the periodontitis status. The rats in normal control group were fed normally. The concentrations of IFN-γ and IL-17 in peripheral blood were measured using enzyme linked immunosorbent assay (ELISA) method at the fourth week after the start of injection and at the eighth week after ligation. The histological of periodontal tissues were observed after hematoxylin-eosin (HE) staining and osteoclast count was performed under light microscope. The histological of osteoclasts were observed after tartrate-resistant acid phosphatase (TRAP) staining. Expression of IFN-γ and IL-17 were detected by immunohistochemical assay.@*Results@#The concentrations of IFN-γ in peripheral blood of LPS group [(185.0±50.7) ng/L] and ligation group [(202.9±60.4) ng/L] were significantly higher than that of normal control group [(106.3±17.2) ng/L](P<0.05). Meanwhile, histological examination showed inflammatory cells infiltration in the gingival epithelium, the height reduction of alveolar bone accompanied with absorption lacuna. There were significantly higher HE and TRAP stained osteoclasts in LPS group (9.50±1.05) and ligation group (10.83±1.17) than that in controlgroup (0.33±0.52)(P<0.05). Moreover, the expressions of IL-17 in alveolar bone absorption area of LPS group and ligation group were significantly stronger than that in control group (P<0.05).@*Conclusions@#The rat models of experimental periodontitis and alveolar bone resorption could be successfully established by means of ligationand LPS injection, respectively. The periodontal inflammatory responses were related to secreting cytokines IFN-γ and IL-17 of Th1 and Th17 cells, while Th17 cells might exert a positive effect on alveolar bone destruction.