J. Lin

Subgingival microbiome in patients with healthy and ailing dental implants.

Dental implants are commonly used to replace missing teeth. However, the dysbiotic polymicrobial communities of peri-implant sites are responsible for peri-implant diseases, such as peri-implant mucositis and peri-implantitis. In this study, we analyzed the microbial characteristics of oral plaque from peri-implant pockets or sulci of healthy implants (n = 10), peri-implant mucositis (n = 8) and peri-implantitis (n = 6) sites using pyrosequencing of the 16S rRNA gene. An increase in microbial diversity was observed in subgingival sites of ailing implants, compared with healthy implants. Microbial co-occurrence analysis revealed that periodontal pathogens, such as Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia, were clustered into modules in the peri-implant mucositis network. Putative pathogens associated with peri-implantitis were present at a moderate relative abundance in peri-implant mucositis, suggesting that peri-implant mucositis an important early transitional phase during the development of peri-implantitis. Furthermore, the relative abundance of Eubacterium was increased at peri-implantitis locations, and co-occurrence analysis revealed that Eubacterium minutum was correlated with Prevotella intermedia in peri-implantitis sites, which suggests the association of Eubacterium with peri-implantitis. This study indicates that periodontal pathogens may play important roles in the shifting of healthy implant status to peri-implant disease.

Magnetic bead-based salivary peptidome profiling analysis during orthodontic treatment durations

Orthodontic treatment induces various biological responses, including tooth movement and remodeling of alveolar bone. Although some studies have investigated the contribution of orthodontic procedures to changes in saliva conditions, little is known about the effects of different treatment durations on the saliva proteome. To identify the discriminating protein profiles in unstimulated whole saliva of orthodontic patients with different treatment durations, we used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) combined with magnetic bead, and peptide mass fingerprints were created by scanning MS signals. Saliva samples from 40 patients (10 in each of four groups: the group without an appliance and groups under treatment for 2, 7, and 12 months) were analyzed. The results showed eight mass peaks with significant differences. Furthermore, mass peak intensities at proteins 1817.7, 2010.7, 2744 and 2710.2 Da represented a steady time-dependent increasing trend, whereas protein 4134 Da exhibited a decreasing tendency. Differential expression of the peptidome profile also occurred in the multiple comparisons, and we established a fitting model. Thus, the potential discriminating biomarkers investigated in this study reflected the complicated changes in periodontal tissues during orthodontic treatment and indicated dynamic interactions between orthodontic treatment and the saliva proteome. The results provide novel insights into alterations in salivary proteins due to different orthodontic treatment durations and may lead to the development of a therapeutic monitoring strategy for orthodontics.

Magnetic bead-based salivary peptidome profiling for periodontal-orthodontic treatment

BackgroundPatients with periodontitis seek periodontal-orthodontic treatment to address certain functional and aesthetic problems. However, little is known of the effect of periodontitis on orthodontic treatment. Thus, we compared the differences in peptide mass fingerprints of orthodontic patients with and without periodontitis by MALDI-TOF MS using a magnetic bead-based peptidome analysis of saliva samples. In this way, we aimed to identify and explore a panel of differentially-expressed specific peptides.ResultsSaliva samples from 24 patients (eight orthodontic patients without periodontitis, eight with periodontitis and another eight with periodontitis but no orthodontic treatment) were analyzed, and peptide mass fingerprints were created by scanning MS signals using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) combined with magnetic beads. Nine mass peaks showed significant differences. Orthodontic patients in the group without periodontal disease showed higher mass peaks for seven peptides of the nine, whereas the mass peaks for the other two peptides were higher in the periodontal-orthodontic patients. Besides, these differentially-expressed peptides were sequenced.ConclusionsThe elucidated candidate biomarkers indicated interactions between periodontal condition and orthodontic treatment and their contributions to the changes of saliva protein profiles. Our results provide novel insight into the altered salivary protein profile during periodontal-orthodontic treatment, and may lead to the development of a therapeutic monitoring strategy for periodontics and orthodontics.

Salivary biomarkers indicate obstructive sleep apnea patients with cardiovascular diseases

Although obstructive sleep apnea (OSA) patients are at high risk of developing cardiovascular disease (CVD), only a small proportion is currently diagnosed. To explore and identify the differentially expressed proteins/peptides of OSA patients with CVDs, a mass spectrometry-based salivary analysis was performed. In our study, eleven peaks were observed differentially expressed in saliva from the non-CVD and CVD groups. Five masses mass peaks (1594.1, 1673.7, 1196.6, 1290.5, and 1447.0 Da) showed an upregulated trend in the CVD group, whereas six mass peaks (3038.6, 2164.3, 2301.4, 3195.0, 2628.4, and 1721.9 Da) were downregulated in the CVD group. In addition, the alpha-2-HS-glycoprotein (AHSG) levels in saliva were verified to be decreased in CVD group compared to non-CVD group. Analysis of the salivary peptidome provides a promising approach to screening for novel biomarkers before further identification, and may contribute to early diagnosis of CVD patients with OSA.

Exosome Analysis: A Promising Biomarker System with Special Attention to Saliva

Today, exosome-related studies have become a focus in science and technology. Recently, three scientists won the Nobel Prize for determining the mechanisms of exosomal transport, making exosomes a promising biomarker system for disease diagnosis and treatment. This review provides a general introduction of exosomes and explores the recent progress on the function, application, isolation, and identification of exosomes as biomarkers in blood and other body fluids, especially in saliva. Detailed information of exosomal proteins and RNAs is discussed in the paper because of their ability to determine the function of exosomes. Due to their noninvasive assessment for quick and convenient diagnosis of diseases, salivary exosomes may well be promising biomarkers.

Inhibition of mechanical stress-induced NF-κB promotes bone formation.

OBJECTIVE Nuclear factor kappaB (NF-κB) plays an important role in osteogenesis. This study was performed to investigate the effects of mechanical force on NF-κB activity in osteoblast-like cells. MATERIALS AND METHODS U2OS cells were harvested at specific time points after mechanical loading. U2OS nuclear extracts were prepared for Western blot assay and electrophoretic mobility shift assay electrophoretic mobility shift assay (EMSA). Total RNA was isolated using TRIzol for real-time PCR. RESULTS P-p65 (Ser536) expression in the nucleus was significantly higher after loading force on U2OS cells. The amount of nuclear NF-κB also increased. Ammonium pyrrolidinedithiocarbamate(PDCT) inhibited compressive force-induced NF-κB activity in EMSA. Further, PDTC attenuated the transcriptional inhibition of alkaline phosphatase (ALP), RUNX-2 and Osteocalcin by down-regulating NF-κB activity. CONCLUSIONS Mechanical force enhances NF-κB activity in osteoblast-like cells, and compressive force affects the downstream bone marker genes through NF-κB.

Magnetic Bead-Based Serum Peptidome Profiling in Patients with Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a frequent medical condition during pregnancy. Early diagnosis and treatment of GDM are crucial for both the mother and the baby. In the present study, we aimed to identify specific biomarkers to assist in the early detection of GDM and give some clues to the possible causes of GDM by comparing serum peptide profile differences between GDM patients and healthy controls. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used in combination with weak cation exchange magnetic bead (WCX-MB). Levels of four peptides (4418.9, 2219.7, 2211.5, and 1533.4 Da) were significantly different. Interestingly, three of them (4418.9, 2211.5, and 1533.4 Da) were identified when GDM patients with two degrees of glucose intolerance were compared. Additionally, peptides 2211.5 and 1533.4 Da showed a decreasing trend as glucose intolerance increased, while peptide 4418.9 Da exhibited the reverse tendency. In conclusion, our study provides novel insights into the altered serum peptide profile of GDM patients. The specific candidate biomarkers may contribute to the development of GDM.

Exploring the Genomic Diversity and Cariogenic Differences of Streptococcus mutans Strains Through Pan-Genome and Comparative Genome Analysis

Pan-genome refers to the sum of genes that can be found in a given bacterial species, including the core-genome and the dispensable genome. In this study, the genomes from 183 Streptococcus mutans (S. mutans) isolates were analyzed from the pan-genome perspective. This analysis revealed that S. mutans has an “open” pan-genome, implying that there are plenty of new genes to be found as more genomes are sequenced. Additionally, S. mutans has a limited core-genome, which is composed of genes related to vital activities within the bacterium, such as metabolism and hereditary information storage or processing, occupying 35.6 and 26.6% of the core genes, respectively. We estimate the theoretical core-genome size to be about 1083 genes, which are fewer than other Streptococcus species. In addition, core genes suffer larger selection pressures in comparison to those that are less widely distributed. Not surprisingly, the distribution of putative virulence genes in S. mutans strains does not correlate with caries status, indicating that other factors are also responsible for cariogenesis. These results contribute to a more understanding of the evolutionary characteristics and dynamic changes within the genome components of the species. This also helps to form a new theoretical foundation for preventing dental caries. Furthermore, this study sets an example for analyzing large genomic datasets of pathogens from the pan-genome perspective.

Proteomic Analysis of RBP4/Vitamin A in Children with Cleft Lip and/or Palate

Cleft of the lip and/or palate (CLP) is one of the most common congenital craniofacial defects. Non-syndromic CLP (NSCLP) is a multifactorial disease influenced by the interaction of genetic and environmental factors. However, there are few studies reporting on the developmental or metabolic status of babies with NSCLP after birth. In our study, we sought to identify and evaluate the differential expression of serum protein profiles in NSCLP children and unaffected babies. Thus, a ‘shotgun proteomics’ approach was first used to analyze the plasma proteome of 13 children with NSCLP and 10 control children, aged 2 to 3.5 years. In total, more than 300 proteins were identified in the serum sample. With gene ontology (GO) analysis, we detected many differentially expressed proteins that could be related to NSCLP, including those involved in lipoprotein metabolism, insulin-like growth-factor-related processes, and so on, especially the proteins involved in retinol transport. Retinol binding protein 4 (RBP4), one protein of the retinol transport category, was significantly decreased in the NSCLP group. Thus, serum vitamin A levels were further determined by high-performance liquid chromatography (HPLC). A significant difference (p < .01) was also found in vitamin A concentrations, consistent with the trend of RBP4. Our results indicated that reduced levels of RBP4 and vitamin A were related to newborns with NSCLP and should thus receive more attention. These results also suggest that vitamin A supplementation might be necessary at an early stage.

Salivary Peptidomic Analysis -The Extension of Proteomics

Nowadays, proteomic-related studies have developed rapidly and improvement has been made in the scientific and technological fields. Besides the proteome, the peptidome with low molecular weight has apparently attracted increasing attention in recent years too. The peptidome performs a large array of vital biological functions to contribute to homeostasis in the certain tissues. However, due to the interference by high-abundance proteins in complex biological body fluids such as saliva and serum, selective enrichment of peptides with low molecular weight is the first and most important step before analyzing the peptidome. This review mainly illustrates the general concept of the peptidome, specific methods of saliva collection, advanced peptidomic technologies and the recently developed peptidomic-related reports, as well as some limitations of the application in salivary peptidome. The future prospects of the peptidome are also involved.