Longitudinal quantification of the gingival crevicular fluid proteome during progression from gingivitis to periodontitis in a canine model

Mass spectrometry-based proteomics profiling of dogs with and without oral diseases: a systematic review

BACKGROUND

Understanding the distinct proteomics profiles in dogs' oral biofluids enhances diagnostic and therapeutic insights for canine oral diseases, fostering cross-species translational research in dentistry and medicine. This study aimed to conduct a systematic review to investigate the similarities and differences between the oral biofluids' proteomics profile of dogs with and without oral diseases.

METHODS

PubMed, Web of Science, and Scopus were searched with no restrictions on publication language or year to address the following focused question: "What is the proteome signature of healthy versus diseased (oral) dogs' biofluids?" Gene Ontology enrichment and the Kyoto Encyclopedia of Genes and Genomes pathway analyses of the most abundant proteins were performed. Moreover, protein-protein interaction analysis was conducted. The risk of bias (RoB) among the included studies was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Studies Reporting Prevalence Data.

RESULTS

In healthy dogs, the proteomic analysis identified 5,451 proteins, with 137 being the most abundant, predominantly associated with 'innate immune response'. Dogs with oral diseases displayed 6,470 proteins, with distinct associations: 'defense response to bacterium' (periodontal diseases), 'negative regulation of transcription' (dental calculus), and 'positive regulation of transcription' (oral tumors). Clustering revealed significant protein clusters in each case, emphasizing the diverse molecular profiles in health and oral diseases. Only six studies were provided to the JBI tool, as they encompassed case-control evaluations that compared healthy dogs to dogs with oral disease(s). All included studies were found to have low RoB (high quality).

CONCLUSION

Significant differences in the proteomics profiles of oral biofluids between dogs with and without oral diseases were found. The synergy of animal proteomics and bioinformatics offers a promising avenue for cross-species research, despite persistent challenges in result validation.

Proteome Analysis of Oral Biofluids in Periodontal Health and Disease Using Mass Spectrometry

Mass spectrometry-based proteomic approaches permit the high-throughput assessment of proteins from oral biofluids, therefore, allowing a deeper insight into the mechanistic study of periodontal disease. Here we describe an entire experimental design of proteomic workflow for oral biofluids, exemplified by saliva and gingival crevicular fluid collected from periodontal health or disease subjects and using a label-free quantification strategy for mass spectrometric data acquisition.

Discovery, validation, and diagnostic ability of multiple protein-based biomarkers in saliva and gingival crevicular fluid to distinguish between health and periodontal diseases

Aim

To discover and validate differential protein biomarker expression in saliva and gingival crevicular fluid (GCF) to discriminate objectively between periodontal health and plaque‐induced periodontal disease states.

Materials and Methods

One‐hundred and ninety participants were recruited from two centres (Birmingham and Newcastle upon Tyne, UK) comprising healthy, gingivitis, periodontitis, and edentulous donors. Samples from the Birmingham cohort were analysed by quantitative mass spectrometry proteomics for biomarker discovery. Shortlisted candidate proteins were then verified by enzyme‐linked immunosorbent assay in both cohorts. Leave‐one‐out cross validation logistic regression analysis was used to identify the best performing biomarker panels.

Results

Ninety‐five proteins were identified in both GCF and saliva samples, and 15 candidate proteins were selected based upon differences discovered between the donor groups. The best performing panels to distinguish between: health or gingivitis and periodontitis contained matrix metalloproteinase‐9 (MMP9), S100A8, alpha‐1‐acid glycoprotein (A1AGP), pyruvate kinase, and age (area under the curve [AUC] 0.970); health and gingivitis contained MMP9, S100A8, A1AGP, and pyruvate kinase, but not age (AUC 0.768); and mild to moderate and advanced periodontitis contained MMP9, S100A8, A1AGP, pyruvate kinase, and age (AUC 0.789).

Conclusions

Biomarker panels containing four proteins with and without age as a further parameter can distinguish between periodontal health and disease states.

Evaluation of the Use of Platelet-Rich Fibrin Xenologous Membranes Derived from Bubaline Blood in Canine Periodontal Defects

Periodontal disease is the most common oral disease in dogs. Platelet-rich fibrin (PRF) is widely utilized to facilitate soft and hard tissue healing and has been proposed in periodontal healing in small animal treatment. However, the quality and amount of autologous PRF is compromised in animals with systemic diseases. The present study aimed to evaluate the efficacy of xenologous bubaline blood-derived PRF (bPRF) on periodontal tissue healing in canine periodontal defects. Split-mouth design was employed in twenty dogs diagnosed with periodontal disease. The defects were divided randomly into two groups: the open-flap debridement (OFD)-treated group and the OFD with bPRF (OFD+bPRF) application group. Results demonstrated that gingival index and periodontal probing depth decreased significantly in the OFD+bPRF group compared with those treated with OFD alone. Application of bPRF in periodontal defects also promoted fibrous tissue formation, as confirmed by the marked increase in fibrosis score. bPRF application significantly increased COL1A1 and PDGFB mRNA levels at day 14 compared with the baseline. Taking this evidence together, bPRF provided a favorable therapeutic modality in canine periodontal defects. bPRF could be an alternative biomaterial for the treatment of periodontal defects in dogs.

Pyruvate Kinase, Inflammation and Periodontal Disease

Pyruvate kinase (PK) is the final and rate-limiting enzyme in glycolysis. It has four isoforms PKM1, PKM2, PKL and PKR. PK can form homo tetramers, dimers or monomers. The tetrameric form has the most catalytic activity; however, the dimeric form has non-canonical functions that contribute to the inflammatory response, wound healing and cellular crosstalk. This brief review explores these functions and speculates on their role in periodontal disease.

The potential impact of salivary peptides in periodontitis

Periodontitis is a complex immune-inflammatory condition characterized by the disruption of the periodontal ligament and subsequent formation of periodontal pockets, and by alveolar bone loss, often resulting in tooth loss. A myriad of factors, namely, genetic, metabolic, immunological, and inflammatory, is associated with progression of periodontitis. Periodontitis is also associated with systemic conditions such as neoplastic disorders, obesity, and diabetes. The current diagnosis of this disease relies on clinical measurements such as clinical attachment loss and probing depth, which have poor precision due to patient, operator and probe-related factors. Thus, there is a need to develop reliable, objective, and reproducible biomarkers for early diagnosis of periodontitis. In this regard, saliva, with contributions from the gingival crevicular fluid, holds great potential. However, most of the information on biomarkers of periodontium-related salivary proteins has come from studies on the molecular pathogenesis of periodontitis. In periodontitis, a more holistic approach, such as the use of -omics technologies, for biomarker discovery, is needed. Herein, we review the biomarkers proposed to date for the assessment of periodontitis, with emphasis on the role of salivary peptides in periodontitis and their assessment by high-throughput saliva proteomics. We also discuss the challenges pertaining to the identification of new periodontitis biomarkers in saliva.

Peptidomic changes of saliva after nonsurgical treatment of stage I / II generalized periodontitis

OBJECTIVE

To explore the changes of peptidome profiles of saliva, serum and gingival crevicular fluid (GCF) before and after nonsurgical periodontal treatment in patients with generalized periodontitis (stage I / II).

SUBJECTS AND METHODS

Saliva, serum and GCF samples were collected from 17 patients at baseline (T₀ ), one week after ultrasonic supragingival scaling (T₁ ) and eight weeks after subgingival scaling and root planning (T₂ ). Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) was carried out to detect changes in peptidomic profiles. Then nano-liquid chromatography-electrospray ionization-tandem mass spectrometry (nano-LC/ESI-MS/MS) was performed to identify potential peptide biomarkers.

RESULTS

Most of the peptides from the patients exhibited a decreasing trend from the time point of pre-treatment to that of post-treatment. Cluster analysis and scatter plots using these peptides indicated that salivary peptidome has an acceptable capability of reflecting the status of stage I / II generalized periodontitis. Seven of these peptides were successfully identified as α-1-antitrypsin, immunoglobulin κ variable 4-1, haptoglobin and immunoglobulin heavy constant γ2.

CONCLUSIONS

Certain peptides in saliva, serum and GCF were down-regulated after nonsurgical periodontal treatment, demonstrating the application prospects of saliva in monitoring and surveillance of periodontal diseases in both clinical settings and communities.

Host-microbe interactions: Profiles in the transcriptome, the proteome, and the metabolome

Periodontal studies using transcriptomics, proteomics, and metabolomics encompass the collection of mRNA transcripts, proteins, and small-molecule chemicals in the context of periodontal health and disease. The number of studies using these approaches has significantly increased in the last decade and they have provided new insight into the pathogenesis and host-microbe interactions that define periodontal diseases. This review provides an overview of current molecular findings using -omic approaches that underlie periodontal disease, including modulation of the host immune response, tissue homeostasis, and complex metabolic processes of the host and the oral microbiome. Integration of these -omic approaches will broaden our perspective of the molecular mechanisms involved in periodontal disease, advancing and improving the diagnosis and treatment of various stages and forms of periodontal disease.

Ability of S100 proteins and matrix metalloproteinase-9 to identify periodontitis in a ligature-induced periodontitis dog model

AIMS

The present study aimed to monitor the levels of selected salivary biomarkers during the development and treatment of periodontitis and to evaluate their ability to identify periodontitis in dogs.

MATERIALS AND METHODS

A total of 15 beagle dogs were divided into a control group (no ligature), group 1 (ligature on six teeth), and group 2 (ligature on 12 teeth). The experimental periods consisted of 8 weeks of periodontitis induction and 4 weeks of treatment. Clinical measurements and the sampling of saliva were performed every 4 weeks. The levels of S100A8, S100A9, S100A8/A9, and matrix metalloproteinase (MMP)-9 were measured by enzyme-linked immunosorbent assay.

RESULTS

All experimental animals and two control animals developed periodontitis, which was successfully treated. All salivary biomarkers were significantly increased in periodontitis with high diagnostic power (c-index ≥ 0.944) and were able to identify animals with periodontitis on a single tooth. Whereas the levels of salivary S100A8/A9 recovered to levels in health, those of S100A8, S100A9, and MMP-9 in periodontitis stability remained significantly higher than in health.

CONCLUSION

Salivary S100A8, S100A9, S100A8/A9, and MMP-9 may be used for the screening of periodontitis in dogs, but with caution of other conditions that can affect their levels in saliva.

Proteomic Investigations of In Vitro and In Vivo Models of Periodontal Disease

Proteomics has currently been a developing field in periodontal diseases to obtain protein information of certain samples. Periodontal disease is an inflammatory disorder that attacks the teeth, connective tissues, and alveolar bone within the oral cavity. Proteomics information can provide proteins that are differentially expressed in diseased or healthy samples. This review provides insight into approaches researching single species, multi species, bacteria, non-human, and human models of periodontal disease for proteomics information. The approaches that have been taken include gel electrophoresis and qualitative and quantitative mass spectrometry. This review is carried out by extracting information about in vitro and in vivo studies of proteomics in models of periodontal diseases that have been carried out in the past two decades. The research has concentrated on a relatively small but well-known group of microorganisms. A wide range of models has been reviewed and conclusions across the breadth of these studies are presented in this review.

Microbiota of periodontal pockets and root canals in induced experimental periodontal disease in dogs

AIM

To investigate the relationship between the microbiota of periodontal pockets (PP) and root canals (RC) in dogs submitted to experimental periodontal disease (ExPD).

METHODS

ExPD was induced by combining cotton and wire ligatures. After 125 days, microbiological samples were collected from PP and RC. Strains isolated from 19 teeth were submitted to DNA extraction, 16S rRNA gene amplification and gene sequencing. Pearson's χ² - and Fisher's exact tests and McNemar's test were used when appropriate.

RESULTS

The number of species in PP was greater than in RC, with prevalence of obligate anaerobes and Gram-negative bacteria. In the PP predominated Fusobacterium necrophorum, Porphyromonas gingivalis, Prevotella loescheii, Campylobacter gracilis and Veillonella parvula. In the RC samples, 9 had microbial growth, with predominance of the following genera: Staphylococcus, Streptococcus and Neisseria. Eight genera were common to both sites in the same tooth. PP presented a greater number of species than the RC. No significant difference was observed in the species found in PP and RC in the same tooth.

CONCLUSION

Microbial composition of the RC could be modulated by the presence of periodontal disease, especially in cases of severe periodontal destruction. RC microbiota was less complex and diverse than the PP.

Gingival Exudatome Dynamics Implicate Inhibition of the Alternative Complement Pathway in the Protective Action of the C3 Inhibitor Cp40 in Nonhuman Primate Periodontitis

Periodontitis is a prevalent chronic inflammatory disease associated with dysbiosis. Although complement inhibition has been successfully used to treat periodontitis in animal models, studies globally analyzing inflamed tissue proteins to glean insight into possible mechanisms of action are missing. Using quantitative shotgun proteomics, we aimed to investigate differences in composition of inflammatory gingival tissue exudate ("gingival crevicular fluid"; GCF), before and after local administration of an inhibitor of the central complement component, C3, in nonhuman primates. The C3 inhibitor, Cp40 (also known as AMY-101) was administered locally in the maxillary gingival tissue of cynomolgus monkeys with established periodontitis, either once a week (1×-treatment; n = 5 animals) or three times per week (3×-treatment; n = 10 animals), for 6 weeks followed by another 6 weeks of observation in the absence of treatment. 45 GCF samples were processed for FASP digestion and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Data were processed using the ProgenesisQI software. The statistical significance of differences between the groups was determined by RM-ANOVA, and a protein expression change was considered as a true regulation at >2-fold and p < 0.05. The human orthologues were subjected to Gene Ontology analyses using PANTHER. Data are available via ProteomeXchange with identifier PXD009502. 573 proteins with >2 peptides were longitudinally quantified. Both 3× and 1× administration of Cp40 resulted in significant down-regulation of dozens of proteins during the 6-week course of treatment as compared to baseline. Following drug withdrawal at 6 weeks, more than 50% of the down-regulated proteins showed increased levels at week 12. The top scored pathway was "complement activation, alternative pathway", and several proteins involved in this pathway were down-regulated at 6 weeks. We mapped the proteomic fingerprint changes in local tissue exudate of cynomolgus monkey periodontitis in response to C3 inhibition and identified the alternative pathway of complement activation and leukocyte degranulation as main targets, which are thus likely to play significant roles in periodontal disease pathogenesis. Label-free quantitative proteomics strategies utilizing GCF are powerful tools for the identification of treatment targets and providing insights into disease mechanisms.

The Saliva Proteome of Dogs: Variations Within and Between Breeds and Between Species

Saliva is a complex multifunctional fluid that bathes the oral cavity to assist in soft and hard tissue maintenance, lubrication, buffering, defense against microbes, and initiating digestion of foods. It has been extensively characterized in humans but its protein composition in dogs remains poorly characterized, yet saliva composition could explain (patho) physiological differences between individuals, breeds and with humans. This pilot discovery study aimed to characterize canine saliva from two breeds, Labrador retrievers and Beagles, and to compare this with human saliva using quantitative mass spectrometry. The analysis demonstrated considerable inter-individual variation and difference between breeds; however these were small in comparison to the differences between species. Functional mapping suggested roles of detected proteins similar to those found in human saliva with the exception of the initiation of digestion as salivary amylase was lacking or at very low abundance in canine saliva samples. Many potential anti-microbial proteins were detected agreeing with the notion that the oral cavity is under continuous microbial challenge.

Longitudinal quantification of the gingival crevicular fluid proteome during progression from gingivitis to periodontitis in a canine model

Aim

Inflammatory periodontal disease is widespread in dogs. This study evaluated site‐specific changes in the canine gingival crevicular fluid (GCF) proteome during longitudinal progression from very mild gingivitis to mild periodontitis. Periodontitis diagnosis in dogs requires general anaesthesia with associated risks and costs; our ultimate aim was to develop a periodontitis diagnostic for application in conscious dogs. The objective of this work was to identify potential biomarkers of periodontal disease progression in dogs.

Material and Methods

Gingival crevicular fluid was sampled from a total of 10 teeth in eight dogs at three different stages of health/disease and samples prepared for quantitative mass spectrometry (data available via ProteomeXchange; identifier PXD003337). A univariate mixed model analysis determined significantly altered proteins between health states and six were evaluated by ELISA.

Results

Four hundred and six proteins were identified with 84 present in all samples. The prevalence of 40 proteins was found to be significantly changed in periodontitis relative to gingivitis. ELISA measurements confirmed that haptoglobin was significantly increased.

Conclusions

This study demonstrates for the first time that proteins detected by mass spectrometry have potential to identify novel biomarkers for canine periodontal disease. Further work is required to validate additional biomarkers for a periodontitis diagnostic.