Association of interleukin-4 and interleukin-17F polymorphisms in periodontitis in Dravidian ethnicity

BACKGROUND:

Complex network of pro and anti-inflammatory cytokines are known to act in inflamed periodontal tissue. This study explores the distribution of interleukin (IL)-4 (+33 C/T) and IL-17F (7383A/G, 7488A/G) gene polymorphism in chronic and aggressive periodontitis subjects of Dravidian ethnicity.

MATERIALS AND METHODS:

This case control study consisted of 124 periodontitis individuals comprising of 63 chronic and 61 aggressive periodontitis subjects as cases, and control group consisted of 101 healthy subjects. All subjects were genotyped for IL-4 + 33C/T, IL-17F 7383A/G, 7488A/G by polymerase chain reaction amplification followed by TaqMan assay for IL-4 + 33C/T, restriction enzyme digestion and gel electrophoresis for IL-17F 7383A/G and sequencing for IL-17F 7488A/G.

RESULTS:

IL-4 + 33C/T was significantly associated with periodontitis (P < 0.05) at both allelic and genotypic level. In subgroup analysis also significant difference (P < 0.05) in allelic distribution between aggressive periodontitis and control group for loci IL-4 + 33C/T was noted. However, there was a lack of association between IL-17F 7383A/G and IL-17F 7488A/G with periodontitis and its sub-groups at both allelic and genotypic levels.

CONCLUSIONS:

In Malayalam speaking Dravidian population IL-4 + 33C/T loci appears to be an important risk factor for periodontal disease with a leaning towards aggressive periodontitis. The association between IL-17F at 7383A/G and 7488A/G loci with either chronic or an aggressive periodontitis could not be ascertained.     

Protective effects of crocin on biochemistry and histopathology of experimental periodontitis in rats

ABSTRACT

We investigated the effectiveness of crocin for preventing oxidative damage in experimentally produced periodontitis. We used three groups of 10 female Wistar rats divided into: control (C); experimental periodontitis (EP), experimental periodontitis + crocin (Cr-EP). Malondialdehyde (MDA), glutathione (GSH), total antioxidant status (TAS), total oxidant status (TOS) and superoxide dismutase (SOD) and catalase (CAT) enzyme activities were measured. We examined histopathology and inflammatory cell infiltration in gingiva and periodontal ligament. MDA and TOS levels, and SOD and CAT activities increased significantly in rats with induced periodontitis compared to the control group, while GSH and TAS levels were decreased significantly compared to the control group. Histopathologic examination revealed inflammatory cell infiltration in gingiva epithelium and subepithelial connective tissue in the EP group. Histological damage was reduced significantly after crocin treatment compared to the EP group. Crocin supplementation may help reduce oxidative damage to periodontal tissues.     

Porphyromonas gingivalis infection and cell death in human aortic endothelial cells

Porphyromonas gingivalis is a periodontal pathogen that promotes a proatherogenic response in endothelial cells. Cell death responses of human aortic endothelial cells to P. gingivalis at various multiplicities of infection (MOI) were investigated by assessment of cell detachment, histone-associated DNA fragmentation, lactate dehydrogenase release and ADP:ATP ratio. Porphyromonas gingivalis at MOI 1:10-1:100 did not have a cytotoxic effect, but induced apoptotic cell death at MOI 1:500 and 1:1000. Monocyte chemoattractant protein-1 production was significantly enhanced by P. gingivalis at MOI 1:100. At higher MOI, at least in vitro, P. gingivalis mediates endothelial apoptosis, thereby potentially amplifying proatherogenic mechanisms in the perturbed vasculature.     

不同根管冲洗方法在瘘管型根尖周炎治疗中的疗效分析

目的:比较普通冲洗和超声冲洗方法对瘘管型慢性根尖周炎一次性根管治疗疗效的影响,以期为超声冲洗方法在慢性根尖周炎临床治疗中的应用提供指导。方法:将2010年6月-2012年6月来我科就诊的166名瘘管型慢性根尖周炎患者随机分为2组,超声冲洗组和普通冲洗组,根据分组分别在一次性根管治疗术中的根管清理过程采用超声根管冲洗方法和普通注射器冲洗方法,术后1周和半年时复诊记录患者一次性根管治疗效果,通过以患者术后1周内的主观"疼痛程度"作为短期评价指标和术后半年治疗效果作为长期评价指标进行比较,采用X2检验进行统计分析。结果:与普通注射器冲洗方法相比,超声冲洗方法可以明显减低一次性根管治疗后短期不适症状的发生率(P0.05),特别是重度反应的发生(P0.05);而术后出现的轻度和中度疼痛反应无明显差异。同时,超声冲洗方法可以明显增加一次性根管治疗术的长期成功率(P0.05)。结论:一次性根管治疗术中使用超声冲洗方法替代常规注射器冲洗方法,能够明显减轻患者短期术后以"疼痛"为主要表现的不适症状,提高一次性根管治疗术在瘘管型根尖周治疗中的长期成功率,是一种较为理想的根管治疗冲洗方法。     

CSF1 gene associated with aggressive periodontitis in the Japanese population

Aggressive periodontitis (AgP) is characterized by the early onset of the rapid and progressive destruction of the alveolar bone. We investigated the correlation of single nucleotide polymorphisms (SNPs) in candidate genes with AgP in the Japanese population in order to determine the genetic risk factors for this complex disease. Among 11 genes related to bone formation and resorption, 43 known SNPs were tested in 98 case and 88 control samples for association with AgP by using SNP genotyping techniques. Among these, three polymorphisms located in the colony stimulating factor 1 (CSF1) gene showed a positive association with AgP. This is the first case of an association between a CSF1 polymorphism and a human disease.     

Vitapex糊剂在根管治疗乳牙慢性根尖周炎中的效果分析

目的:探讨Vitapex糊剂在根管治疗乳牙慢性根尖周炎中的效果。方法:选取200例慢性根尖周炎患儿并随机分为两组,观察组(108例)给予Vitapex糊剂充填,对照组(92例)给予氧化锌碘仿糊剂充填,比较两组治疗后1个月的充填质量、治疗前后的VAS评分及治疗后6个月的远期疗效。结果:治疗后1个月,两组患者的根管充填质量构成比比较有统计学差异(P0.05),观察组根管适充率高于对照组;治疗前两组VAS评分相比,无统计学差异(P0.05);治疗后1周、1个月,两组痛觉减轻且观察组痛觉感受更轻微(P0.05)。治疗后随访6个月,观察组治疗成功104例,成功率96.3%;对照组治疗成功80例,成功率87.0%,观察组治疗成功率高于对照组(P0.05)。结论:Vitapex糊剂填充过程简易,易于填充,对乳牙根尖周炎具有较好的治疗效果,能减轻患儿牙痛,远期疗效较佳。     

Immunohistochemical localization of TLR2 and CD14 in gingival tissue of healthy individuals and patients with chronic periodontitis

We used immunohistochemistry to quantify and compare the expression of Toll-like receptor 2 (TLR2) and cluster of differentiation 14 (CD14) in gingival tissues of both healthy individuals and patients with chronic periodontitis. We also correlated the expression of TLR2 and CD14 with the histological grades of chronic periodontitis. We examined 30 gingival specimens from chronic periodontitis patients and 10 from healthy individuals. Tissues from both groups were immunostained with antibodies against TLR2 and CD14. TLR2 and CD14 were expressed by endothelial cells, fibroblasts, lymphocytes and plasma cells. The immunohistochemical expression of TLR2 and CD14 was significantly greater in inflammatory cells of the chronic periodontitis group than in healthy individuals. Expression of these molecules was greater in the inflammatory cells of connective tissue adjacent to pocket epithelium in both groups. The expression of TLR2 and CD14 was greatest in the periodontitis group that was classified as severe grade, followed by moderate and mild grades, which suggests a role of TLR2 and CD14 in the pathogenesis of chronic periodontitis. The positive correlation of TLR2 and CD14 expression levels with the severity grades of chronic periodontitis suggests that they are correlated also with disease severity; therefore, they may be useful for predicting disease progression. Our findings are consistent with the possibility that CD14 acts as a co-receptor for TLR2.     

Effects of IL-13 on TGF-β and MMP-1 in periodontitis

Periodontitis is an inflammatory disease of the supporting tissues of the teeth. Interleukin (IL)-13 is a multifunctional T-helper type2 (Th2) cytokine that can diminish inflammatory responses. I investigated using ELISA the effects of IL-13 on transforming growth factor-beta (TGF-β) and matrix metalloproteinase-1 (MMP-1). MMP-1 was detected using immunohistochemistry. Gingival fibroblasts were stimulated with IL-13 or together with tumor necrosis factor-α (TNF-α). I found that macrophage-like cells, fibroblast-like cells, vascular endothelial cells and gingival epithelial cells were stained more intensely for MMP-1 and were observed more frequently in the periodontitis affected group than in the control group. The cultured gingival fibroblasts with IL-13 produced more TGF-β than unstimulated cells. After stimulation with additional TNF-α, MMP-1 production was diminished. IL-13 may play a role in regulating collagen homeostasis in gingival fibroblasts. IL-13 induces both up-regulation of TGF-β, a cytokine known to stimulate production of collagen, and down-regulation of collagen-destroying MMP-1 production. This effect may be strong during periodontitis when Th2 cells assist T cells.     

Structure of the lysine specific protease Kgp from Porphyromonas gingivalis,a target for improved oral health

The oral pathogen Porphyromonas gingivalis is a keystone pathogen in the development of chronic periodontitis. Gingipains, the principle virulence factors of P. gingivalis are multidomain, cell‐surface proteins containing a cysteine protease domain. The lysine specific gingipain, Kgp, is a critical virulence factor of P. gingivalis. We have determined the X‐ray crystal structure of the lysine‐specific protease domain of Kgp to 1.6 Å resolution. The structure provides insights into the mechanism of substrate specificity and catalysis.     

Circ_0062491 alleviates LPS-induced apoptosis and inflammation in periodontitis by regulating miR-498/SOCS6 axis

Periodontitis is a prevalent chronic inflammatory disease. Circular RNAs (circRNAs) have been revealed to play roles in the inflammatory response. Hence, this work aimed to explore the role and mechanism of circ_0062491 in periodontitis progression. Human periodontal ligament cells (PDLCs) were isolated from the periodontal ligament (PDL) of the healthy teeth with orthodontic requirement after tooth extraction. In vitro experiments were conducted by cell counting Kit-8 (CCK-8) assay, flow cytometry, Western blot, and ELISA to determine cell viability, apoptosis, and inflammatory response. The binding between miR-498 and circ_0062491 or SOCS6 was confirmed using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Circ_0062491 expression was decreased in periodontitis and LPS-induced PDLCs. Restoration of circ_0062491 attenuated LPS-induced apoptosis and inflammation in PDLCs in vitro. Mechanistically, circ_0062491 functioned as a sponge for miR-498, and miR-498 directly targeted SOCS6. Rescue experiments showed that miR-498 up-regulation reversed the protective action of circ_0062491 on PDLCs under LPS treatment. Moreover, silencing of miR-498 protected PDLCs from LPS-induced apoptosis and inflammation, which were abolished by SOCS6 knockdown. Circ_0062491 protected PDLCs from LPS-induced apoptosis and inflammation, suggesting a new target for the amelioration of periodontitis patients.