Objectives To explore the gene polymorphism of a new susceptibility gene Anoctamin 6 (ANO6) related to disease risk of Ankylosing Spondylitis (AS), and the abnormal expression of ANO6 in AS patients. And provide theoretical basis for ANO6 involved in the pathogenesis of AS.
Methods Direct sequencing was performed to explore disease-related SNP in exon and transcription regulatory region of ANO6 between 417AS patients and 541 healthy controls (HCs), and linkage disequilibrium and haplotype analysis was used with candidate SNP. RT-PCR was performed to test the difference of the expression of mRNA in peripheral blood mononuclear cells (PBMCs) between 40 AS patients and 32 HCs. Immunohistochemistry was employed to discover the difference of protein expression in tendon tissues between 9 AS patients and 5 control subjects.
Results Age and sex were not significantly different between AS cases and controls. Our study found that risk alleles of 5 SNP loci (rs79662606, rs76186361, rs17095830, rs80224086 and rs75712006)had a significant correlation with the susceptibility of AS, and strong linkage disequilibrium among each two of SNP loci. Haplotype analysis dicovered a higher proportion of GTGCG, CATGTA and ACGTA in cases (p<0.001). The expression of mRNA of peripheral blood mononuclear cells is 0.49±0.21 in AS cases and 0.86±0.38 in HCs, and the difference is significant (p<0.001). The expression of ANO6 protein went up in tendon tissues (p=0.001), and average Histoscore of IHC in 9 AS patients (182.22±30.732) was significantly higher than in 5 controls (62.00±35.637)(P=0.001).
Conclusions ANO6 is the new susceptibility gene of AS and risky haplotype is GTGCG, ATGTA and ACGTA. The risky haplotype have no relationship with phenotype of AS. The expression of mRNA of PBMCs decreased while the expression of ANO6 protein went up in tendon tissues, which suggested that ANO6 might participant in the generation and development of AS.
Disclosure of Interest None declared