Open AccessRole of Fibroblast Activation Protein Alpha in Fibroblast-like Synoviocytes of Rheumatoid Arthritis
Author(s) -
Mohammad Javad Mousavi,
Elham Farhadi,
Mohammad Vodjgani,
Jafar Karami,
Mohammad Naghi Tahmasebi,
Arash Sharafat Vaziri,
Marzieh Asgari,
Nima Rezaei,
Shayan Mostafaei,
Ahmadreza Jamshidi,
Mahdi Mahmoudi
Publication year - 2021
Publication title -
iranian journal of allergy, asthma and immunology
Language(s) - English
Resource type - Journals
eISSN - 1735-5249
pISSN - 1735-1502
DOI - 10.18502/ijaai.v20i3.6335
Subject(s) - rheumatoid arthritis , fibroblast , flow cytometry , pathogenesis , downregulation and upregulation , immunology , apoptosis , gene , medicine , chemistry , biology , cell culture , genetics
Fibroblast-like synoviocytes (FLSs) have been introduced in recent years as a key player in the pathogenesis of rheumatoid arthritis (RA), but the exact mechanisms of their transformation and intracellular pathways have not yet been determined. This study aimed to investigate the role of fibroblast activation protein-alpha (FAP-α) in the regulation of genes involved in the transformation and pathogenic activity of RA FLSs. Synovial FLSs were isolated from RA patients and non-arthritic individuals (n=10 in both groups) and characterized; using immunocytochemistry and flow cytometry analysis. FLSs were divided into un-treated and Talabostat-treated groups to evaluate the FAP-α effect on the selected genes involved in cell cycle regulation (p21, p53, CCND1), apoptosis (Bcl-2, PUMA), and inflammatory and destructive behavior of FLSs (IL-6, TGF-β1, MMP-2, MMP-9, P2RX7). Gene expression analysis was performed by quantitative real-time polymerase chain reaction (qRTPCR), and immunoblotting was carried out to evaluate FAP-α protein levels. The basal level of FAP-α protein in RA patients was significantly higher than non-arthritic control individuals. However, no differences were observed between RA and non-arthritic FLSs, at the baseline mRNA levels of all the genes. Talabostat treatment significantly reduced FAPα protein levels in both RA and non-arthritic FLSs, however, had no effect on mRNA expressions except an upregulated TGF-β1 expression in non-arthritic FLSs. A significantly higher protein level of FAP-α in FLSs of RA patients compared with that of healthy individuals may point to the pathogenic role of this protein in RA FLSs. However, more investigations are necessary to address the mechanisms mediating the FAP-α pathogenic role in RA FLSs.