Upregulation of miR-107 suppresses Wnt3a/β-catenin signaling in degenerated intervertebral disc cells following hyperbaric oxygen treatment—in vitro and in vivo study
التفاصيل البيبلوغرافية
العنوان:
Upregulation of miR-107 suppresses Wnt3a/β-catenin signaling in degenerated intervertebral disc cells following hyperbaric oxygen treatment—in vitro and in vivo study
Background: MicroRNA (miRNA) 107 expression is downregulated but Wnt3a protein and β-catenin are upregulated in degenerated intervertebral disc (IVD). We investigated mir-107/Wnt3a-β-catenin signaling in degenerated nucleus pulposus cells (NPCs) following hyperbaric oxygen (HBO) treatment. Methods: MiRNA profiling was accomplished via microarray and real-time PCR. MiRNA targets were identified using bioinformatics and a luciferase reporter assay. After HBO treatment, the changes in Wnt3a, phosphorylated LRP6, β-catenin, cyclinD1, metalloproteinases (MMPs) were evaluated. In addition, the translocation of β-catenin was detected, the TOP flash and FOP flash activity and the secreted MMPs were quantified. Subsequently, we investigated the effects of HBO on Wnt3a /β-catenin expression and serum keratan sulfate (KS) levels in a rabbit degenerated IVD model. Results: Our results showed ninety-six miRNAs were upregulated and 66 downregulated following HBO intervention. The 3′ untranslated region (UTR) of the Wnt3a mRNA contained the “seed-matched-sequence” for miR-107. MiR-107 was induced by HBO and a marked suppression of Wnt3a was observed simultaneously in degenerated NPCs. Knockdown of miR-107 upregulated Wnt3a expression in hyperoxic cells. HBO downregulated the protein expression of Wnt3a, phosphorylated LRP6, and cyclin D1. There was decreased TOP flash activity following HBO stimulation, whereas the FOP flash activity was not affected. HBO decreased the nuclear translocation of β-catenin and decreased the secretion of MMP 3 and 9. Moreover, rabbit serum KS levels and the area stained positive for Wnt3a and β-catenin tended to be lower in the HBO group. Conclusions: HBO inhibits Wnt3a/β-catenin signaling related pathways by upregulating miR-107 expression in degenerated NPCs. HBO may play a protective role against IVD degeneration and could be used as a future therapeutic treatment
