Ankylosing spondylitis monocyte-derived macrophages express increased level of A2A adenosine receptor and decreased level of ectonucleoside triphosphate diphosphohydrolase-1 (CD39), A1 and A2B adenosine receptors.

Abstract

Macrophages play an important role in the ankylosing spondylitis (AS) auto-inflammatory responses and fibrocartilage destruction. Adenosine is a key modulator of inflammatory conditions. The various effects of adenosine are mediated by its interaction with adenosine receptors (AR). In this study, we investigated the mRNA expression of A1, A2A, A2B, and A3 adenosine receptors, ectonucleoside triphosphate diphosphohydrolase-1 (CD39), and ecto-5'-nucleotidase (CD73) in the monocyte-derived macrophages from AS patients in comparison to healthy controls. We also explored the correlation between analyzed gene expression and patients' clinical manifestations. Whole blood-separated monocytes from 23 healthy controls and 23 active AS patients were stimulated by macrophage colony-stimulating factor (M-CSF) for 7days and differentiated to macrophages. Monocyte and macrophage markers were analyzed by flow cytometry. Analysis of adenosine receptors (ADORA1، ADORA2A، ADORA2B، ADORA3), CD39 and CD73 gene expression was performed by SYBR green real-time PCR. Our results demonstrated monocyte-derived macrophages from AS patients expressed increased level of A2AAR and reduced level of A1, A2BAR, and CD39 mRNA compared to healthy controls. We found an inverse correlation between A2AAR mRNA expression and Bath Ankylosing Spondylitis Functional Index (BASFI) score in AS patients. According to our results, altered expression level of adenosine-relying system would be involved in AS macrophage dysfunction and inflammation and correlated with functional status in AS patients.