Association of peptidoglycan recognition protein 1 to post-myocardial infarction and periodontal inflammation: A subgroup report from the PAROKRANK (Periodontal Disease and the Relation to Myocardial Infarction) study

Probing the salivary proteome for prognostic biomarkers in response to non-surgical periodontal therapy

AIM

This prospective study investigated the salivary proteome before and after periodontal therapy.

MATERIALS AND METHODS

Ten systemically healthy, non-smoking, stage III, grade C periodontitis patients underwent non-surgical periodontal treatment. Full-mouth periodontal parameters were measured, and saliva (n = 30) collected pre- (T0), and one (T1) and six (T6) months post-treatment. The proteome was investigated by label-free quantitative proteomics. Protein expression changes were modelled over time, with significant protein regulation considered at false discovery rate <0.05.

RESULTS

Treatment significantly reduced bleeding scores, percentages of sites with pocket depth ≥5 mm, plaque and gingival indexes. One thousand seven hundred and thirteen proteins were identified and 838 proteins (human = 757, bacterial = 81) quantified (≥2 peptides). At T1, 80 (T1 vs. T0: 60↑:20↓), and at T6, 118 human proteins (T6 vs. T0: 67↑:51↓) were regulated. The salivary proteome at T6 versus T1 remained stable. Highest protein activity post- versus pre-treatment was observed for cellular movement and inflammatory response. The small proline-rich protein 3 (T1 vs. T0: 5.4-fold↑) and lymphocyte-specific protein 1 (T6 vs. T0: 4.6-fold↓) were the top regulated human proteins. Proteins from Neisseria mucosa and Treponema socranskii (T1 vs. T0: 8.0-fold↓, 4.9-fold↓) were down-regulated.

CONCLUSIONS

Periodontal treatment reduced clinical disease parameters and these changes were reflected in the salivary proteome. This underscores the potential of utilizing saliva biomarkers as prognostic tools for monitoring treatment outcomes.

Association of salivary TREM-1 and PGLYRP1 inflammatory markers with non-communicable diseases

AIM

Triggering receptor expressed on myeloid cells 1 (TREM-1) and peptidoglycan recognition protein 1 (PGLYRP1) are elevated in biofluids in the presence of various inflammatory conditions. This cross-sectional study aimed to evaluate the effect of age, sex, smoking and different oral and systemic non-communicable diseases on the levels of TREM-1 and PGLYRP1 in saliva.

MATERIALS AND METHODS

In total, 445 individuals (mean age 48.7 ± 16.9 years, female:male 51%:49%) were included. All provided self-reported information on smoking and systemic diseases and whole stimulated saliva. Periodontal and cariological parameters were recorded. Salivary levels of TREM-1, PGLYRP1 and total protein were measured using commercially available assays.

RESULTS

Salivary TREM-1 levels were significantly higher in stages III-IV periodontitis compared to other periodontal diagnoses (p < .05). Smoking, bleeding on probing (BOP), percentage of pockets ≥4 mm and the number of manifest caries were associated with TREM-1 (p < .05), while sex, BOP, number of manifest caries and muscle and joint diseases were associated with PGLYRP1 (p < .05).

CONCLUSIONS

Salivary TREM-1 is associated with periodontitis and caries, while PGLYRP1 is associated with gingival inflammation and caries. Additionally, TREM-1 levels are modified by smoking, while PGLYRP1 is modified by sex and muscle and joint diseases. TREM-1 and PGLYRP1 in saliva could serve as potential biomarkers for detecting and monitoring non-communicable diseases.

Value of gingival crevicular fluid TREM-1, PGLYRP1, and IL-1β levels during menopause

OBJECTIVE

This study aimed to investigate the association of GCF TREM-1, PGLYRP1, and IL-1β levels with periodontal health in pre- and postmenopausal women.

BACKGROUND

Triggering receptor expressed on myeloid cells 1 (TREM-1), activated through its ligand peptidoglycan recognition protein 1 (PGLYRP1), stimulates proinflammatory cytokine production, such as interleukin (IL)-1β, during periodontal inflammation. Postmenopausal changes may modulate these immune-inflammatory functions. No clinical study has yet investigated the effect of menopause on TREM-1, PGLYRP1, and IL-1β levels in gingival crevicular fluid (GCF).

METHODS

This cross-sectional study included 148 women (age range = 35-65 years), divided into postmenopausal women (PMW) (n = 76, mean age = 54 ± 5 years) and regularly menstruating premenopausal women (RMPW) (n = 72, mean age = 40 ± 4 years). Clinical periodontal parameters were recorded. TREM-1, PGLYRP1, and IL-1β levels were quantified with enzyme-linked immunosorbent assays. Pearson's Chi-squared test and Mann-Whitney-U test were used to compare categorical and numerical variables, respectively. Spearman's Rho correlation analysis was used to test the linear relationship between variables. Analyte level data were categorized based on the periodontal diagnosis and menopause status (2 × 2 nonparametric factorial ANOVA).

RESULTS

No significant differences in TREM-1, PGLYRP1, and IL-1β levels between PMW and RMPW were observed (p > .05). Mean values of periodontal indexes including probing depth did not differ significantly between PMW and RMPW groups (p = .474). TREM-1 levels were significantly higher in both PMW and RMPW with periodontitis, compared to gingivitis or health (p = .0021).

CONCLUSION

Menopause-related changes have no observable effect on GCF levels of TREM-1, PGLYRP1, and IL-1β. Higher GCF TREM-1 levels in women with periodontitis regardless of their menopausal status indicate that TREM-1 may be an indicator for periodontitis both in premenopausal and postmenopausal women.

Comparative Proteomic Analysis of Milk-Derived Extracellular Vesicles from Dairy Cows with Clinical and Subclinical Mastitis

Extracellular vesicles (EVs) are membranous vesicles found in biological fluids with essential functions. However, milk-derived EV proteins from clinical mastitis (CM) and subclinical mastitis (SM) cows have yet to be studied in detail. In this study, milk-derived EVs of CM, SM, and Healthy cows were extracted using a combination of acetic acid/ultracentrifugation and density gradient ultracentrifugation and analyzed using a shotgun proteomic by data-independent acquisition mode. A total of 1253 milk exosome proteins were identified and quantified. Differently enriched (DE) proteins were identified as given a Benjamini−Hochberg adjusted p < 0.05 and a fold change of at least 2. There were 53 and 1 DE proteins in milk-derived EVs from CM and SM cows compared with healthy cows. Protein S100-A9, Protein S100-A8, Chitinase-3-like protein 1, Haptoglobin, Integrin beta-2, and Chloride intracellular channel protein 1 were more abundant in the CM group (adjusted p < 0.05). Still, their enrichment in the SM group was not significant as in the Healthy group. The enrichment of DE proteins between CM and Healthy group was consistent with elevated GO (Gene Ontology) processes—defense response, defense response to Gram-positive bacterium, granulocyte chemotaxis also contributed to Reactome pathways—neutrophil degranulation, innate immune system, and antimicrobial peptides in the CM group. These results provide essential information on mastitis-associated proteins in milk-derived EVs and indicate the biological functions of milk-derived EVs proteins require further elucidation.