CCL18 INDUCES HEALTHY FIBROBLAST-LIKE SYNOVIOCYTES MIGRATION POTENTIALLY VIA ACTIVATION OF TOLL-LIKE-RECEPTOR PATHWAY AND NF-KAPPA-B PATHWAY SIMILAR IN RHEUMATOID ARTHRITIS PATIENTS
- Yuebin Tan, United States of America
Abstract
Background and Aims
Chemokine ligand 18 (CCL18) is wieldy found elevated in synovial fluid (500ng/mL) in rheumatoid arthritis (RA) patients. Enriched CCL18 promotes fibroblast-like-synoviocytes in RA (RA-FLS) migration and facilities RA progression. To explore mechanism of CCL18 regulatory role in synoviocyte migration and associated pathway in RA-FLS would be benefit to RA disease investigation.
Methods
RA-FLS were obtained from Parker-Pearson needle biopsy of RA-patients. Primary normal fibroblast-like synoviocytes (HFLS) were purchased from CellApplications Inc. Total RNA was isolated from HFLS treated with CCL18 (500ng/mL) or vehicle, and five clinical RA-FLS cases. RNA-Sequencing and DESeq2 were implemented to extract differentiation expression genes (DEGs). Kyoto Encyclopedia of Genes and Genomes Gene Set Enrichment Analysis (KEGG-GSEA) on DEGs identified significant pathway involvement. In vitro Oris migration assay confirmed CCL18-stimulated HFLS migration.
Results
at 60h posted stopper-removal in Oris migration assay, the stopper-removal areas were filled with more migrated cells in the HFLS treated with CCL18 than with vehicle (p<0.001) (Fig 1A). Multiple pathways were activated in HFLS treated with CCL18 by KEGG-GSEA (p<0.05) (Fig 1B) and in RA-FLS (data not-shown). Toll-like receptor signaling pathway and NF-kappa B signaling pathway were activated in both HFLS+CCL18 and RA-FLS when compared with HFLS. In GSEA, these two pathways shared similar leading-edge subset with upregulated genes (Fig 1C and Fig 1D). Most upregulated genes shared in both HFLS+CCL18 and RA-FLS were characterized as RA-associated inflammation and pathogenesis factors, such as TRL4, TRL5, NFKB1 and RELA.
Conclusions
CCL18 increase synoviocyte migration by activation of NF-kappa-B and Toll-like-receptor signaling pathways similar in rheumatoid arthritis pathogenesis.