Analysis of circular RNA expression profile of pathological bone formation in ankylosing spondylitis

To screen and analyze the function of specific CircRNAs involved in pathological bone formation in patients with ankylosing spondylitis (AS).From September 2019 to October 2020, hip capsule tissues obtained from 3 patients with AS developed hip joint fusion and 3 patients with femoral neck fracture (FNF) were obtained. The circular RNA expressions of hip capsule were analyzed by Arraystar CircRNA chip. qRT-PCR analysis wan performed to identify the expression patterns of differentially expression CircRNAs.Our findings showed that there were 25 up-regulated and 39 down-regulated differential CircRNAs. Among these CircRNAs, we screened 10 highest up-regulatedCircRNAs and 13 lowest down-regulated CircRNAs (Fold Change≥2,P<0.05). In further verification analysis, hsa_circ_0067103, hsa_circ_0004496, and hsa_circ_0002649, ACTG1 were significantly upregulated, while hsa_circ_0020273, hsa_circ_0005699, and hsa_circ_0048764 were markly downregulated in AS tissue than FNF controls.The expression of CircRNAs involved of pathological bone formation in AS were significantly different from those of control group. These differentially expressed Circular RNAs may be closely related to the occurrence and development of pathological bone formation in AS.