AB0145 Regulation of osteoblasts by alkaline phosphatase in ankylosing spondylitis. (12th June 2018)

• Record Type: Journal Article
• Authors: Jo, S.; Han, J.; Lee, Y.L.; Kim, T.-H.
• Is Part Of: Annals of the rheumatic diseases. Volume 77(2018)Supplement 2
• Page Start: 1264
• Page End: 1264
• Publication Date: 2018-06-12
• Subjects: Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/annrheumdis-2018-eular.6048
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : Background: Ankylosing spondylitis (AS) is characterized by excessive spinal ankylosis and bone formation. Alkaline phosphatase (ALP) activity is reported to be high in AS, but little is known about the molecular relationship between ALP and AS. Objectives: The aims of this study were to investigate the relevance of ALP to AS and the role of ALP in the regulation of osteoblast differentiation in AS. Methods: The high-throughput data were downloaded from Gene Expression Omnibus with accession numbers GSE73754 and GSE41038. We retrospectively collected the ALP levels of male patients with AS, to compare with those of gender and age-matched healthy controls (HC) and rheumatoid arthritis (RA) patients. Total ALP and ALP activity in patient's sera were measured in AS and RA groups. ALP gene expression and intracellular ALP activity were analyzed in microarray data of primary bone-derived cells (BdCs) and in In Vitro experiments. Furthermore, the effect of ALP knockdown and inhibitor were performed in primary BdCs and human osteoblasts cells, respectively. Results: ALP level was increased in AS compared with RA and HC. Increased ALP level in AS was associated with radiograph progression. ALP expression was also enriched in bone tissue of AS patients. Furthermore, AS BdCs exhibited elevated ALP activity, leading to accelerating osteoblastic activity and differentiation. Intriguingly, suppression of ALP expression and activity inhibited expression of osteoblastic genes, which are critical for osteogenic differentiation. Conclusions: A multifaceted analysis showed ALP was highly expressed in AS patients. ALP may be involved in the ankylosis of AS and a therapeutic target for preventing ankylosis. Disclosure of Interest: None declared