Relationship between Gingival Crevicular Fluid Microbiota and Cytokine Profile in Periodontal Host Homeostasis.

As potential biomarkers in periodontitis, microbiome, and cytokines have recently been extensively investigated, but combined analyses of the variations between the microbial structure and cytokine composition are rare. The present study aimed to investigate whether there are differences in the combined profile of microbiome and cytokines in individuals with or without periodontitis. The microbiome and cytokine composition in gingival crevicular fluid (GCF) from 16 patients and 15 controls from Jishi Shan (Gansu, China) were analyzed using 454 pyrosequencing and RayBio Quantibody Arrays. The results showed that a higher co-occurrence of genera in periodontitis group compared with the healthy group, as evaluated by Schoener's abundance-based co-occurrence index. C-reactive protein (CRP) was significantly (P < 0.05) higher in the GCF of the periodontitis group while interleukin (IL)-8 was significantly (P < 0.01) higher in the GCF of the healthy group. The Mantel test revealed a significant concordance between cytokines and microbiota, in the healthy group (Mantel statistic r = 0.36, P ≤ 0.05) but not in the periodontitis group (Mantel statistic r = 0.013, P = 0.434). The results were further confirmed by the Procrustes test. Matrix metalloproteinase (MMP)-9, osteoactivin, IL-8, and macrophage inflammatory protein (MIP)-1a were significantly associated with bacterial composition at the phylum, class, order, family, and genus levels. CRP was also associated with bacterial composition at the species level. In conclusion, alterations in the polymicrobial community structure leads to disruption in the healthy correlation between cytokines and microbiomes. This dysbiosis between the microbiota and the immune response could be one of the major etiological mechanisms underlying periodontitis.

Exploration of Human Salivary Microbiomes--Insights into the Novel Characteristics of Microbial Community Structure in Caries and Caries-Free Subjects.

Recently, high-throughput sequencing has improved the understanding of the microbiological etiology of caries, but the characteristics of the microbial community structure in the human oral cavity with and without caries are not completely clear. To better understand these characteristics, Illumina MiSeq high-throughput sequencing was utilized to analyze 20 salivary samples (10 caries-free and 10 caries) from subjects from the same town in Dongxiang, Gansu, China. A total of 5,113 OTUs (Operational Taxonomic Units, 97% cutoff) were characterized in all of the salivary samples obtained from the 20 subjects. A comparison of the two groups revealed that (i) the predominant phyla were constant between the two groups; (ii) the relative abundance of the genera Veillonella, Bifidobacterium, Selenomonas, Olsenella, Parascardovia, Scardovia, Chryseobacterium, Terrimonas, Burkholderia and Sporobacter was significantly higher in the group with caries (P < 0.05); and (iii) four genera with low relative abundance (< 0.01% on average), including two characteristic genera in caries (Chryseobacterium and Scardovia), significantly influenced the microbial community structure at the genus and OTU levels. Moreover, via co-occurrence and principal component analyses, the co-prevalence of the pathogenic genera was detected in the caries samples, but in the caries-free samples, the function of clustered genera was more random. This result suggests that a synergistic effect may be influencing the assembly of the caries microbial community, whereas competition may play a more dominant role in governing the microbial community in the caries-free group. Our findings regarding the characteristics of the microbial communities of the groups with and without caries might improve the understanding of the microbiological etiology of caries and might improve the prevention and cure of caries in the future.

[Microbial Community Structure on the Root Surface of Patients with Periodontitis.]

OBJECTIVES: To study the microbial community structure on the root surface of patients with periodontitis. METHODS: Bacterial plaque and tissues from the root neck (RN group),root middle (RM group) and root tine (RT group) of six teeth with mobility 3 in one patient with periodontitis were sampled.The V3V4 region of 16S rRNA was sequenced on the Illumina MiSeq platform.The microbial community structure was analyzed by Mothur,Qiime and SPSS software. RESULTS: The principal component analysis (PCoA) results indicated that the RM samples had a similar microbial community structure as that of the RT samples,which was significant different from that of the RN samples.Thirteen phyla were detected in the three groups of samples,which included 7 dominant phyla.29 dominant genera were detected in 184 genera.The abundance of Bacteroidetes_[G-6] and Peptostre ptococcaceae_[XI][G-4] had a positive correlation with the depth of the collection site of samples (P<0.05),while the abundance of Prevotella,Selenomonas,Corynebacterium and Olsenella had a negative correlation with the depth of the collection site of samples (P<0.05). CONCLUSIONS: There is region-specificity of microbial community structure on the root surface of patients with periodontitis.

[Effect of emodin on proliferation and cell cycle of human oral squamous carcinoma Tca8113 cells in vitro].

OBJECTIVE: To investigate the effect of emodin on proliferation and cell cycle distribution of human oral squamous carcinoma cells in vitro. METHODS: Cultured human oral squamous carcinoma Tca8113 cells were treated with 2.5, 5, 10, 20, 40, 60 and 80 µmol/L emodin for 24, 48 or 72 h, with the cells treated with 0.1% DMSO as control. MTT assay and flow cytometry were used to evaluate the changes in cell proliferation and cell cycle distribution, respectively. Western blotting was employed to analyze the changes in the expression levels of the cell cycle-related proteins CDK2, cyclin E and P21 after emodin treatment. RESULTS: Emodin significantly inhibited the growth and proliferation of Tca8113 cells within 72 h in a time- and dose-dependent manner, and caused cell cycle arrest in G0-G1 phase. Western blotting revealed that emodin treatment significantly lowered the expression levels of CDK2, cyclin E and P21 proteins in Tca8113 cells (P<0.05). CONCLUSION: Emodin can inhibit the proliferation of Tca8113 cells and affect their cell cycle distribution possibly by inhibiting the signaling pathways of cell cycle regulation.

Bcl-xL overexpression and its association with the progress of tongue carcinoma.

Apoptosis-related protein B-cell lymphoma-extra large (Bcl-xL) has a crucial role in the control of cell death through its inhibition of apoptosis. This study was designed to investigate the expression of Bcl-xL in relation to the development of tongue carcinoma and whether it has potential as a marker for the clinical diagnosis of tongue carcinoma and as a therapeutic target to evaluate the dynamic of tongue carcinoma progression. A statistical analysis of 100 cases oral tongue carcinoma tissue specimens were performed using pathological grading and clinical TNM staging, and 14 cases corresponding non-tumor tissues as control. The changes in Bcl-xL mRNA expression between different pathological grades and clinical TNM stages of tissue were analyzed by RT-PCR. Additionally, immunohistochemical SP method and Western blot assays were employed to detect changes in Bcl-xL protein expression in different tongue carcinoma tissues. The results showed the expression of Bcl-xL was significantly higher in tongue carcinoma tissues than in normal tongue tissues and was positively associated with the degree of differentiation and the clinical TNM staging, but negatively correlated with the degree of malignancy of the tumor. There was higher expression of Bcl-xL in oral tongue squamous cell carcinoma (OTSCC) tissues compared with oral tongue adenocarcinoma (OTA) tissues, but Bcl-xL expression in tissue with lymph node metastasis was significantly higher than that without lymph node metastasis. Thus, Bcl-xL overexpression may be closely related to the dynamic of the pathogenesis and development of tongue carcinoma. It may be a useful marker for clinical diagnosis and an aid to evaluating the efficacy of therapeutics in tongue carcinoma.