LncRNA-Anrel promotes the proliferation and migration of synovial fibroblasts through regulating miR-146a-mediated annexin A1 expression.

Objective: Increasing evidence demonstrates that long non-coding RNAs (lncRNAs) are closely related to multiple human autoimmune diseases, and their dysregulation is tightly linked to inflammation and disease progression. Nonetheless, little is known about the consequences of aberrant expression of lncRNAs during rheumatoid arthritis (RA) development. In this study, we screened for the expressions of lncRNAs in RA synovial fibroblasts (RA-SF) and investigated their functions in RA-SF proliferation and migration, and the relevant underlying mechanisms.

Methods: The lncRNAs expression profiles were interrogated with microarrays. The expressions of key lncRNAs were confirmed in synovial fibroblasts from RA patients and MH7A cells using qRT-PCR. Proliferations and migrations of MH7A and HFL-1 cells were evaluated using CCK-8 assay and cell migration assay kits, respectively. The expression of inflammatory cytokines (IL-6, IL-1β, and TNF-α) and cell migration related proteins (MMP-1 and MMP-3) were evaluated using qRT-PCR and western blotting. Collagen type II-induced arthritis (CIA) in mice was used as an animal model of RA.

Results: Nine lncRNAs were significantly altered in RA-SF, of which lncRNA-000239 showing the most significant upregulation. Overexpression of lncRNA-000239 significantly enhanced the proliferation and migration of human RS-SF cells (MH7A), while the opposite effect was observed with lncRNA-000239 silencing. Importantly, lncRNA-000239 enhanced annexin A1 expression by upregulating the expression of miR-146a. Moreover, locally enhanced expression of lncRNA-000239 promoted the onset of arthritis in CIA.

Conclusion: These data indicate that lncRNA-000239 upregulates annexin A1 expression via miR-146a and thus, promotes the proliferation and migration of RA-SF. This highlights a potential role of lncRNA-000239 as an inflammatory factor of RA.