Targeted proteomics in a population-based study identifies serum PECAM-1 and TRIM21 as inflammation markers for periodontitis.

OBJECTIVES: Periodontitis (PD) can cause systematic inflammation and is associated with various metabolic processes in the body. However, robust serum markers for these relationships are still lacking. This study aims to identify novel circulating inflammation-related proteins associated with PD using targeted proteomics. MATERIALS AND METHODS: We used population-based, cross-sectional data from 619 participants of the Polish Longitudinal University Study (Bialystok PLUS). Mean pocket probing depth (mPPD) and proportion of bleeding on probing (pBOP) served as exposure variables. Fifty-two inflammation-related proteins were measured using the Olink Target 96 Cardiovascular III and the Olink Target 96 Immune Response panels. Associations between periodontal measures and proteins were tested using covariate-adjusted linear regression models. RESULTS: At a false discovery rate of < 0.05, we identified associations of mPPD and pBOP with platelet-endothelial cell adhesion molecule-1 (PECAM-1) and tripartite motif-containing protein 21 (TRIM21). CONCLUSION: This study revealed novel associations between PD and serum levels of PECAM-1 and TRIM21. Our results suggest that these proteins might be affected by molecular processes that take place in the inflamed periodontium. CLINICAL RELEVANCE: Novel associations of PECAM-1 and TRIM21 with PD indicate promising serum markers for understanding the disease's pathophysiological processes and call for further biomedical investigations.

Links between ectopic and abdominal fat and systemic inflammation: New insights from the SHIP-Trend study.

BACKGROUND: Excessive fat accumulation in adipose tissue depots and organs such as the pancreas and the liver is associated with systemic low-grade chronic inflammation. AIMS: To investigate the association between abdominal, hepatic, and pancreatic fat and the circulating level of inflammatory biomarkers. METHODS: We used data from a subsample of the Study of Health in Pomerania (SHIP-Trend, n = 469). The plasma concentration of 37 inflammatory biomarkers was measured using the Bio-Plex-Pro™-Human-Inflammation-Panel-1. Subcutaneous and visceral adipose tissue (SAT and VAT), as well as hepatic and pancreatic fat, were determined by magnetic resonance imaging. We assessed the associations between fat content and inflammatory biomarkers using multiple linear regression. RESULTS: Hepatic fat was associated with MMP-2 (ß -0.11), PTX3 (ß -0.14), and TNFSF12 (ß -0.06). Pancreatic fat was associated with sTNFR1 (ß 0.15), sTNFR2 (ß 0.11), and sCD163 (ß 0.13). VAT and SAT were associated with sCD163 (ßVAT 0.20, ßSAT 0.16), MMP-2 (ßVAT -0.12, ßSAT -0.10), OSTCN (ßVAT -0.16, ßSAT -0.10), sTNFR1 (ßVAT 0.13, ßSAT 0.13), sTNFR2 (ßVAT 0.13, ßSA 0.12), TNFSF12 (ßVAT -0.11, ßSAT -0.08), and TNFSF14 (ßVAT 0.21, ßSAT 0.20). VAT was additionally associated with TNFSF13B (ß 0.08) and CHI3L1 (ß 0.07). CONCLUSIONS: Our findings provide new insights into the involvement of hepatic and pancreatic fat on systemic inflammation.

Novel associations between inflammation-related proteins and adiposity: A targeted proteomics approach across four population-based studies.

Chronic low-grade inflammation has been proposed as a linking mechanism between obesity and the development of inflammation-related conditions such as insulin resistance and cardiovascular disease. Despite major advances in the last 2 decades, the complex relationship between inflammation and obesity remains poorly understood. Therefore, we aimed to identify novel inflammation-related proteins associated with adiposity. We investigated the association between BMI and waist circumference and 72 circulating inflammation-related proteins, measured using the Proximity Extension Assay (Olink Proteomics), in 3,308 participants of four independent European population-based studies (KORA-Fit, BVSII, ESTHER, and Bialystok PLUS). In addition, we used body fat mass measurements obtained by Dual-energy X-ray absorptiometry (DXA) in the Bialystok PLUS study to further validate our results and to explore the relationship between inflammation-related proteins and body fat distribution. We found 14 proteins associated with at least one measure of adiposity across all four studies, including four proteins for which the association is novel: DNER, SLAMF1, RANKL, and CSF-1. We confirmed previously reported associations with CCL19, CCL28, FGF-21, HGF, IL-10RB, IL-18, IL-18R1, IL-6, SCF, and VEGF-A. The majority of the identified inflammation-related proteins were associated with visceral fat as well as with the accumulation of adipose tissue in the abdomen and the trunk. In conclusion, our study provides new insights into the immune dysregulation observed in obesity that might help uncover pathophysiological mechanisms of disease development.