Porphyromonas gingivalis (P. gingivalis) is one of the main periodontal bacteria. This pathogen was reported to enhance monocyte migration and adhesion to endothelial cells in atherosclerosis. The scavenger receptor lectin-like oxidized lowdensity lipoprotein receptor-1 (LOX-1) plays a pivotal role in atherogenesis. The aim of this study was to investigate whether LOX-1 modulates P. gingivalis-mediated monocyte migration and adhesion to endothelial cells and how it works. The results showed that the migration and adhesion of monocytic THP-1 cells to human umbilical vein endothelial cells (HUVECs) were significantly enhanced when HUVECs or THP-1 cells were challenged with P. gingivalis. Meanwhile, the expression level of LOX-1 in both HUVECs and THP-1 cells were also significantly increased by P. gingivalis stimulation. It is well known that ligand/receptor pairs monocyte chemoattractant protein-1 (MCP-1)/CC chemokine receptor 2 (CCR2), selectins/Integrins, and cell adhesion molecules (CAMs)/Integrins mediate monocyte migration and adhesion to endothelial cells. In this study, LOX-1 was demonstrated to be crucially involved in P. gingivalis-induced THP-1 cell migration and adhesion to HUVECs, by regulating expression of ligands MCP-1, intercellular adhesion molecule-1 (ICAM-1) and E-selectin in HUVECs and that of their receptors CCR2 and Integrin αMβ2 in THP-1 cells. The nuclear factor-kappa B (NF-κB) signaling pathway was proved to be involved in this process. In conclusion, LOX-1 plays a crucial role in P. gingivalis-induced monocyte migration and adhesion to endothelial cells. This result implies LOX-1 may act as a bridge in linking periodontitis to atherosclerosis.

24Several studies have documented the diversity and potential pathogenic associations of 25 organisms in the human oral cavity. Although much progress has been made in 26 understanding the complex bacterial community inhabiting the human oral cavity, our 27 understanding of some microorganisms is less resolved due to a variety of reasons. One 28 such little-understood group is the candidate phyla radiation (CPR), which is a recently 29 identified, but highly abundant group of ultrasmall bacteria with reduced genomes and 30 unusual ribosomes. Here, we present a computational protocol for the detection of CPR 31 organisms from metagenomic data. Our approach relies on a self-constructed dataset 32 comprising published CPR genomic sequences as a filter to identify CPR sequences from 33 metagenomic sequencing data. After assembly and functional prediction, the taxonomic 34 affiliation of CPR contigs can be identified through phylogenetic analysis with publically 35 available 16S rRNA gene and ribosomal proteins, in addition to sequence similarity 36 analyses (e.g., average nucleotide identity calculations and contig mapping). Using this 37 protocol, we reconstructed two draft genomes of organisms within the TM7 superphylum, 38 that had genome sizes of 0.594 Mb and 0.678 Mb. Among the predicted functional genes 39 of the constructed genomes, a high percentage were related to signal transduction, cell 40 motility, and cell envelope biogenesis, which could contribute to cellular morphological 41 changes in response to environmental cues.42 3 Importance 43 Candidate phyla radiation (CPR) bacterial group is a recently identified, but highly 44 diverse and abundant group of ultrasmall bacteria exhibiting reduced genomes and 45 limited metabolic capacities. A number of studies have reported their potential pathogenic 46 associations in multiple mucosal diseases including periodontitis, halitosis, and 47 inflammatory bowel disease. However, CPR organisms are difficult to cultivate and are 48 difficult to detect with PCR-based methods due to divergent genetic sequences. Thus, our 49 understanding of CPR has lagged behind that of other bacterial component. Here, we 50 used metagenomic approaches to overcome these previous barriers to CPR identification, 51 and established a computational protocol for detection of CPR organisms from 52 metagenomic samples. The protocol describe herein holds great promise for better 53 understanding the potential biological functioning of CPR. Moreover, the pipeline could 54 be applied to other organisms that are difficult to cultivate. 55 56 Keywords: candidate phyla radiation (CPR), metagenomics, bioinformatics, 57 computational protocol 58 59 60 61 62 63 4 Introduction 64The human oral cavity is one of the five primary microbial microecosystems within 65 humans, and has been used as a model system for microbiome research (1). Dysbiosis of 66 the oral microbial community has been observed in relation to some common systemic 67 diseases including rheumatoid arthritis (2) and type 2 diab...

IntroductionPlaque control plays a critical role in the prevention and treatment of periodontitis. Antibacterial mouthwash is one of the most important tools for plaque control. Pudilan, including extracts of Scutellaria baicalensis root, Taraxacum mongolicum, Bunge corydalis herb and Isatis indigotica, was reported playing the role of anti-inflammatory and anti-bacterial. However, its effect on dental plaque and periodontal inflammation remains unknown. We aimed to assess the efficacy of Pudilan Keyanning antibacterial mouthwash which contains the active essence of Pudilan and 0.03%–0.06% cetylpyridinium chloride, as well as Pudilan active essence for plaque control and gingival anti-inflammation in patients during periodontal maintenance phase.Methods and analysisIn this double-blind, randomised, placebo-controlled clinical trial, a total of 120 participants during periodontal maintenance phase will be enrolled. After supragingival scaling, they will be randomly assigned into three groups in a 1:1:1 ratio: the Pudilan Keyanning antibacterial mouthwash group, a chlorhexidine acetate mouthwash (0.12%) group or a placebo group with mouthwash containing the same components as the Pudilan Keyanning mouthwash except for Pudilan active ingredients. They will rinse with mouthwash, respectively, two times per day for 6 weeks. Clinical parameters (such as plaque index, bleeding index) and the level of volatile sulfide in the breath will be measured and analysed. The subgingival plaque will be collected and analysed microbiologically. Questionnaire feedback will be analysed.Ethics and disseminationThe study protocol (V.4) was reviewed and approved by the Medical Ethical Committee of Peking University School and Hospital of Stomatology (Ethics Approval No. PKUSSIRB-201950153b). All participants signed a written consent form.Trial registration numberChiCTR2000041253.

Background In periodontitis, noncoding RNAs may play a regulatory role in the immune microenvironment through competitive endogenous RNA. We aimed to profile noncoding RNA expression and construct immune-related ceRNA network in periodontitis. Methods Five inflamed periodontal tissue and five healthy gingivae were collected for whole-transcriptome sequencing. Differential gene, functional enrichment, and protein–protein interaction network analysis were performed to explore the function of differentially expressed genes. CIBERSORTx was used to analyze level of immune cell infiltration in the periodontal tissue. An immune-related competitive endogenous RNA network was constructed and expression of key regulators in the network was validated. Results Compared with healthy gingiva, 200 mRNAs, 90 long noncoding RNAs, 65 microRNAs, and 518 circular RNAs were differentially expressed, and cell chemotaxis was significantly enhanced in inflamed periodontal tissue. Immune cell infiltration analysis showed that neutrophils, macrophages M1, T follicular helper cells, and naive B cells were significantly increased in periodontitis. Key regulators including JUN, FOS, THBS1, KLF2, WIF1, were identified and their expression was then validated. Conclusion We constructed an immune-related competitive endogenous RNA network in periodontal tissue, which provided new insights into immune homeostasis in periodontitis and laid a foundation for further study of noncoding RNAs. Key regulators in this network may be promising targets for future periodontitis treatment.