Comparative salivary proteomics of cleft palate patients

Starch treatment improves the salivary proteome for subject identification purposes

Identification of subjects, including perpetrators, is one of the most crucial goals of forensic science. Saliva is among the most common biological fluids found at crime scenes, containing identifiable components. DNA has been the most prominent identifier to date, but its analysis can be complex due to low DNA yields and issues preserving its integrity at the crime scene. Proteins are emerging as viable candidates for subject identification. Previous work has shown that the salivary proteome of the least-abundant proteins may be helpful for subject identification, but more optimized techniques are needed. Among them is removing the most abundant proteins, such as salivary α-amylase. Starch treatment of saliva samples elicited the removal of this enzyme and that of glycosylated, low-molecular-weight proteins, proteases, and immunoglobulins, resulting in a saliva proteome profile enriched with a subset of proteins, allowing a more reliable and nuanced subject identification.

Salivary proteome of aphthous stomatitis reveals the participation of vitamin metabolism, nutrients, and bacteria

There are currently no preventative options for recurrent aphthous stomatitis, and the only available treatments are palliative. This is partly due to a poor understanding of its etiopathogenesis. In this case-control study, we characterized the salivary proteome of patients with recurrent aphthous stomatitis in the presence and absence of lesions. Through mass spectrometry-based proteomics and bioinformatics tools, we identified that the presence of oral ulcers is associated with several specific biological processes, including the metabolic pathways of vitamin B9, B12, nitrogen, selenium, and the bacterium Neisseria meningitidis. These changes occurred only in the presence of clinically visible lesions, and there were no relevant differences between patients in anatomical regions unaffected by ulcers. Additionally, using western blot and ELISA assays, we verified that carbonic anhydrase 1 (CA1) and hemoglobin subunit beta (HBB) proteins are highly expressed during the ulcerative and remission phases of recurrent aphthous stomatitis. Our results cumulatively support saliva as an indicator of the pathophysiological changes, which occur during the clinical course of lesions. From a clinical perspective, we suggest that recurrent aphthous stomatitis is a condition triggered by temporary biological changes in people with lesions.

The Densitometric Analysis of Protein Pattern in Cleft Lip and Palate Patients

Objectives

Cleft lip and palate (CLP) belongs to the congenital anomaly that is clinically seen as cleft in lip, alveolar bone, palate, and nasal septum. The patients suffer from esthetic and various functional defects. CLP is resulted from impaired palatogenesis during the embryonic phase. The etiology of CLP is influenced by genetic, environmental, and combination of both. According to the literature, CLP is highly associated with defect in interferon regulatory factor 6 (IRF6) and poliovirus receptor-like (PVRL1) genes. The present study aimed to investigate the total protein profile and to identify protein IRF6 and PVRL1 in plasma of CLP patients.

Materials and Methods

Dot-Blot analysis was performed to identify protein target of IRF6 and PVRL1. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was performed in gel concentration 12% using plasma of CLP patients, their parents, and control population. The gels were stained by Coomassie blue afterward. Gels were analyzed through ImageLab 5.2.1 software.

Results

The intensity of major bands in CLP patients was darker than control group, but remains similar to the parents group. The target protein IRF6 and PVRL1 were positively identified through Dot-Blot. Retardation factor value was significantly different in major bands of CLP patients compared to control group.

Conclusion

There pattern of protein profile in CLP patients was different compared to non-CLP.

Role of Salivary Biomarkers in Oral Cancer Detection

Oral cancers are the sixth most frequent cancer with a high mortality rate. Oral squamous cell carcinoma accounts for more than 90% of all oral cancers. Standard methods used to detect oral cancers remain comprehensive clinical examination, expensive biochemical investigations, and invasive biopsy. The identification of biomarkers from biological fluids (blood, urine, saliva) has the potential of early diagnosis. The use of saliva for early cancer detection in the search for new clinical markers is a promising approach because of its noninvasive sampling and easy collection methods. Human whole-mouth saliva contains proteins, peptides, electrolytes, organic, and inorganic salts secreted by salivary glands and complimentary contributions from gingival crevicular fluids and mucosal transudates. This diagnostic modality in the field of molecular biology has led to the discovery and potential of salivary biomarkers for the detection of oral cancers. Biomarkers are the molecular signatures and indicators of normal biological, pathological process, and pharmacological response to treatment hence may provide useful information for detection, diagnosis, and prognosis of the disease. Saliva's direct contact with oral cancer lesions makes it more specific and potentially sensitive screening tool, whereas more than 100 salivary biomarkers (DNA, RNA, mRNA, protein markers) have already been identified, including cytokines (IL-8, IL-1b, TNF-α), defensin-1, P53, Cyfra 21-1, tissue polypeptide-specific antigen, dual specificity phosphatase, spermidine/spermineN1-acetyltransferase , profilin, cofilin-1, transferrin, and many more. However, further research is still required for the reliability and validation of salivary biomarkers for clinical applications. This chapter provides the latest up-to-date list of known and emerging potential salivary biomarkers for early diagnosis of oral premalignant and cancerous lesions and monitoring of disease activity.

Massively Increased Caries Susceptibility in an Irf6 Cleft Lip/Palate Model

Patients with cleft lip/palate (CLP) have been reported, in some studies, to exhibit an increased prevalence of caries, although the underlying cause for this increase is unknown. In genetically defined mouse models, studies of postnatal sequelae associated with CLP have been hampered by neonatal lethality. Using a conditional targeting approach, we ablated the major CLP gene Irf6 only in the late embryonic oral epithelium ( Irf6 cKO), bypassing the role of the gene in lip and palate morphogenesis and thus ensuring survival to adulthood. We report that Irf6 cKO mice present with 1) dysplastic salivary glands due to disruptions of epithelial junctional complexes, likely secondary to elevated activation of RHO GTPases, and 2) increased salivary cell proliferation. These changes result in significantly reduced saliva flow rate and buffering capacity and increased mucus acidity. A marked decrease in expression of CCL27, one of the major mucosal and skin cytokines, was found that correlated with increased bacterial colonization of the oral cavity with the cariogenic pathogen Streptococcus mutans and other bacteria. When placed on a high-sugar diet, Irf6 cKO mice show a 35-fold increase in presentation and severity of dental caries as compared with wild-type control mice. Strikingly, within the 8-wk test period, many molars extensively dissolved, and there was progressive loss of the alveolar bone, likely as a result of increased colonization of periodontal pathogens. These data provide the first mechanistic insight into the heightened caries susceptibility associated with CLP and indicate a direct role for the major CLP gene Irf6 in salivary gland development and a significant role in regulating oral immunity. Our data suggest that careful evaluation of salivary gland function and the implementation of early oral health preventive strategies are warranted to reduce the burden of dental care in this at-risk population.

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

Background

Patients 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.

Results

Saliva 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.

Conclusions

The 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.