Regulation of Salivary Peptidoglycan Recognition Protein 1 in Adolescents

Abstract

Introduction: Peptidoglycan recognition protein 1 (PGLYRP1), a member of peptidoglycan recognition proteins, is known to be involved in the proinflammatory response toward bacterial infections. Recently, PGLYRP1 was identified as a ligand for triggering receptor expressed on myeloid cells 1 (TREM-1). Although PGLYRP1 is involved in immune and inflammatory responses, its levels in initial stages of periodontal disease in adolescents are currently unknown. Objectives: We aimed to investigate salivary levels of PGLYRP1 and its correlation with TREM-1, polymorphonuclear leukocyte elastase (PMN elastase), and an active matrix metalloproteinase 8 (aMMP-8) in adolescents. Methods: Whole saliva samples (n = 537) were collected from 15- to 16-y-old adolescents at Kotka Health Center, Finland, prior to periodontal examination, including measurement of periodontal pocket depth (PPD), visible plaque index (VPI), and bleeding on probing (BOP). Adolescents, clustered as periodontally healthy, gingivitis, or subclinical periodontitis, were tested for salivary levels of TREM-1, PGLYRP1, and PMN elastase by enzyme-linked immunosorbent assay and aMMP-8 by a time-resolved immunofluorometric assay (IFMA). Results: Salivary levels of PGLYRP1 and aMMP-8 were significantly higher in adolescents with subclinical periodontitis and gingivitis compared to individuals with healthy periodontium. TREM-1 and PMN elastase levels were higher in adolescents with subclinical periodontitis compared to healthy individuals but did not reach significance. PGLYRP1 correlated positively with BOP, PPD, VPI, aMMP-8, and TREM-1. Conclusions: Elevated PGLYRP1 levels in adolescents with gingivitis and subclinical periodontitis and its positive correlation with TREM-1 and aMMP-8 may indicate an association of PGLYRP1 with initial stages of periodontal disease. Sex and poor oral hygiene but not smoking are also associated with higher levels of PGLYRP1. However, PGLYRP1 has a lower discriminating capacity and is therefore a less reliable marker alone in the diagnosis of initial stages of periodontal disease in adolescents. Knowledge Transfer Statement: PGLYRP1, a member of peptidoglycan recognition proteins, is a ligand for TREM-1. Elevated PGLYRP1 levels in adolescents with gingivitis and subclinical periodontitis and its positive correlation with TREM-1 and aMMP-8 may indicate an association of PGLYRP1 with initial stages of periodontal disease. However, it has a lower discriminating capacity and is therefore a less reliable marker alone in the diagnosis of periodontal disease in adolescents.

Oral health and emotional well-being in premenopausal and postmenopausal women: a cross-sectional cohort study

“…Although alterations in sex hormone levels affect periodontal tissues and lead to poorer periodontal health [ 1 , 5 , 33 , 34 ], the present study did not identify significant differences regarding periodontal parameters between the two studied groups. There was also no association between osteoporosis scores and increased risk of periodontitis in postmenopausal women [ 35 , 36 ].…”

Elevated serum TREM-1 is associated with periodontitis and disease activity in rheumatoid arthritis

“…TREM-1 and PGLYRP1 levels in various biofluids are elevated in periodontitis patients compared to periodontally-healthy controls [24][25][26][27][28][29] . A recent study investigating 92 inflammatory biomarkers in serum of RA patients with and without periodontitis, identified 17 markers which were significantly elevated in serum of RA patients with periodontitis compared to periodontally-healthy RA patients 53 .…”

“…Several studies have investigated TREM-1 and PGLYRP1 in the context of periodontal disease and recently TREM-1 has been suggested as a candidate marker for new treatment strategies against periodontal diseases 22,23 . Elevated TREM-1 levels were observed in saliva, serum and gingival crevicular fluids (GCF) in patients with periodontitis, and TREM-1 serum and saliva levels correlated positively [24][25][26][27] . PGLYRP1 levels were elevated in saliva and GCF of patients with periodontitis, and initial periodontal therapy decreased PGLYRP1 levels in these patients with a stronger effect in non-smokers [27][28][29] .…”

“…Elevated TREM-1 levels were observed in saliva, serum and gingival crevicular fluids (GCF) in patients with periodontitis, and TREM-1 serum and saliva levels correlated positively [24][25][26][27] . PGLYRP1 levels were elevated in saliva and GCF of patients with periodontitis, and initial periodontal therapy decreased PGLYRP1 levels in these patients with a stronger effect in non-smokers [27][28][29] . Furthermore, TREM-1 and PGLYRP1 have been investigated in the context of the periodontal and systemic disease link 28,[30][31][32] .…”

Blood and Salivary Inflammatory Biomarkers Profile in Patients with Chronic Kidney Disease and Periodontal Disease: A Systematic Review

“…HD complications were related to Staphylococcus aureus and, consequently, with high levels of peptidoglycan recognition protein 1 (PGLYRP1) [ 6 ], showing a possible relationship between HD complications and oral infection. PGLYRP1 functions as a ligand that activates TREM-1 during illness, so the high values of this biomarker indicate that the patient is probably suffering from systematic inflammation due to periodontitis [ 71 , 72 , 73 , 74 ]. Higher values of this biomarker may lead to, or worsen, the prognosis of several diseases, such as rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease, type 1 diabetes, psoriasis cystic fibrosis, sepsis, and even atherosclerotic complications, the latter being one of the leading causes of mortality in patients with CKD [ 71 , 72 , 75 ].…”