miR-200a/b relieves IL-1β-induced cell injury in knee articular chondrocytes ex-vivo by targeting fucosyltransferase 4 (FUT4)

Abstract

Background: Osteoarthritis (OA) is a common subtype of arthritis with prevalence increase with age, and is characterized by the degeneration of articular cartilage. Chondrocytes play curial role in the formation of the articular cartilage. This work aimed to figure out the effect of miR-200a/b in chondrocytes of OA, as well as the underlying molecular mechanism. Methods: Cell viability, apoptosis, pro-inflammatory factors secretion, and matrix degradation were detected with cell counting kit-8 (CCK-8), flow cytometry, enzyme-linked immunosorbent assay (ELISA), and western blotting, separately. Expression of miR-200a/b and fucosyltransferase 4 (FUT4) was measured by RT-qPCR (RNA level) and western blot (protein level). The relationship between miR-200a/b and FUT4 was verified by dual-luciferase assay and RNA immunoprecipitation (RIP) assay. Results: Interleukin 1β (IL-1β) induced OA cell model in primary chondrocytes ex-vivo, as evidenced by cell viability inhibition, apoptosis rate promotion, and IL-6 and tumor necrosis factor α (TNF-α) resection enhancement, as well as Collegen 2a1 (Col2a1) and Aggrecan expression inhibition. Expression of miR-200a/b was downregulated in knee articular cartilage of OA patients and IL-1β-induced primary chondrocytes. miR-200a/b overexpression decreased IL-1β-induced cell injuries, which was further blocked by FUT4 upregulation. Mechanically, FUT4 was negatively regulated by miR-200a/b via target binding. Conclusion: miR-200a/b could alleviate IL-1β-induced chondrocyte injuries via targeting its downstream gene FUT4, suggesting that miR-200a/b-FUT4 axis might be a potential candidate to the treatment of OA.