Drug Design, Development and Therapy (Jun 2019)
TMF inhibits miR-29a/Wnt/β-catenin signaling through upregulating Foxo3a activity in osteoarthritis chondrocytes
Abstract
Xianhua Huang*, Zhixi Chen*, Weimei Shi, Rui Zhang, Linfu Li, Hai Liu, Longhuo WuCollege of Pharmacy, Gannan Medical University, Ganzhou, People’s Republic of China*These authors contributed equally to this work Background: miR-29a, a downstream factor of Wnt/β-catenin signaling, promotes the activity of the Wnt/β-catenin signaling in a positive feedback loop. Our previous work showed that 5,7,3ʹ,4ʹ-tetramethoxyflavone (TMF), a major constituent from Murraya exotica L., exhibited chondroprotective activity by inhibiting the activity of Wnt/β-catenin signaling.Purpose: To investigate whether TMF showed the inhibitory effects on miR-29a/β-catenin signaling by up regulation of Foxo3a expression.Methods: Rat knee OA models were duplicated by using Hulth’s method. TMF (5 μg/mL and 20 μg/mL) was used for administration to cultured cells, which were isolated from the rat cartilages. Analysis of chondrocytes apoptosis, gene expression, and protein expression were conducted. In addition, miR-29a mimics and pcDNA3.1(+)-Foxo3a vector were used for transfection, luciferase reporter assay for detecting the activity of Wnt/β-catenin signaling, and co-immunoprecipitation for determining proteins interaction.Results: TMF down regulated miR-29a/β-catenin signaling activity and cleaved caspase-3 expression and up regulated Foxo3a expression in OA rat cartilages. In vitro, miR-29a mimics down regulated the expression of Foxo3a and up regulated the activity of Wnt/β-catenin signaling and cleaved caspase-3 expression. TMF ameliorated miR-29a/β-catenin-induced chondrocytes apoptosis by up regulation of Foxo3a expression.Conclusion: TMF exhibited chondroprotective activity by up regulating Foxo3a expression and subsequently inhibiting miR-29a/Wnt/β-catenin signaling activity. Keywords: osteoarthritis, chondrocytes apoptosis, miR-29a, Wnt/β-catenin, Foxo3a, TMF
