S100 protein and tryptophan metabolites in rheumatoid arthritis

Abstract

Introduction. To date, many links in the pathogenesis of rheumatoid arthritis remain unclear, which leads to unsatisfactory results in its therapy. The aim of the research. Study of S100 protein changes and tryptophan metabolites in rheumatoid arthritis. Мethods. Experiments were performed on 40 WISTAR rats. At baseline, an intraperitoneal injection of type 2 collagen solution (Chondrex, Inc., USA) in Freund's incomplete adjuvant was performed on each animal of the experimental groups. The tissues were tryptophan, kynurenine, 3-hydroxenurinine, L-5-hydrotryptophan by HPLC with fluorimetric and spectrophotometric detection. The S100 protein was determined by streptavidin-biotin-peroxidase. Chemokine concentrations of C-X-C motif chemokine ligand 1 (CXCL1) and chemokine (C-C motif) ligand 2 (CCL2) were determined using Rat Inflammation Panel V02 multiplex assay kits (Biolegend, USA). using a Cytomics FC500 flow cytofluorimeter (Beckman Coulter, USA). Statistical analysis was performed using Jamovi version 2.3. Results. It was found that the content of CXCL1 increases sharply in the early stages of experimental rheumatoid arthritis, the concentration of CCL2 was high throughout the experiment. The level of S100 protein was consistently high in this pathology. With experimental rheumatoid arthritis, the content of tryptophan metabolites along the kynurenine pathway increases and the concentration of metabolites along the serotonin pathway decreases. Direct positive correlations of the S100 protein with the content of tryptophan metabolites along the kynurenine pathway and negative ones along the serotonin pathway were established. Conclusions. S100 protein, chemokines, and tryptophan metabolites play important roles in the pathogenesis of rheumatoid arthritis.