Shanghai Jiading Nanxiang Hospital, Shanghai, China.
Eur Rev Med Pharmacol Sci. 2018 Mar;22(6):1580-1587. doi: 10.26355/eurrev_201803_14562.
Wnt/β-catenin signaling pathway plays a role in upregulating expression of osteoblast (OB) specific transcriptional factor Osterix and promoting OB differentiation. It was shown that the elevation of the miR-132 level was associated with sclerotizing inhibition. Bioinformatics analysis revealed the complementary binding site between miR-132 and 3'-UTR of β-catenin. This study investigated the influence of miR-214 in regulating β-catenin expression and differentiation of umbilical cord mesenchymal stem cells (UC-MSCs) into OB.
UC-MSCs were induced to differentiate to OB. The expressions of miR-132, β-catenin, Osterix, and ALP, together with ALP activity were detected on day 0, 5, 10, and 15. The regulatory relationship between miR-132 and β-catenin was confirmed by dual luciferase reporter gene assay. UC-MSCs were divided into five groups, including agomir-control, miR-132 agomir, pGPH1-NC, pGPH1-β-catenin, and miR-132 agomir + pGPH1-β-catenin groups. β-catenin, Osterix, and ALP expressions, together with ALP activity were tested after induction for 15 days.
MiR-132 was downregulated, while β-catenin Osterix and ALP expressions, together with ALP activity were enhanced in the process of UC-MSCs differentiating into OBs. MiR-132 agomir and/or pGPH1-β-catenin transfection significantly reduced β-catenin expression, downregulated Wnt/β-catenin signaling pathway activity, declined Osterix level, weakened ALP expression and activity, and attenuated OB differentiation of UC-MSCs.
The level of β-catenin was enhanced, while the miR-132 level was decreased in the process of UC-MSCs differentiating into OBs. Upregulation of miR-132 inhibited the differentiation of UC-MSCs through suppressing β-catenin expression, attenuating Wnt/β-catenin signaling pathway activity, and downregulating Osterix level.
Wnt/β-连环蛋白信号通路在上调成骨细胞（OB）特异性转录因子骨形成蛋白 2（Osterix）的表达和促进 OB 分化中发挥作用。有研究表明，miR-132 水平的升高与硬化抑制有关。生物信息学分析显示，miR-132 与 β-连环蛋白 3'-UTR 之间存在互补结合位点。本研究探讨了 miR-214 对调节β-连环蛋白表达以及脐带间充质干细胞（UC-MSCs）向 OB 分化的影响。
诱导 UC-MSCs 向 OB 分化。分别在第 0、5、10 和 15 天检测 miR-132、β-连环蛋白、Osterix 和碱性磷酸酶（ALP）的表达以及 ALP 活性。通过双荧光素酶报告基因检测证实 miR-132 与 β-连环蛋白之间的调控关系。将 UC-MSCs 分为 5 组，包括 agomir-control、miR-132 agomir、pGPH1-NC、pGPH1-β-catenin 和 miR-132 agomir+pGPH1-β-catenin 组。诱导 15 天后检测各组β-连环蛋白、Osterix 和 ALP 的表达以及 ALP 活性。
UC-MSCs 向 OB 分化过程中，miR-132 表达下调，β-连环蛋白、Osterix 和 ALP 的表达以及 ALP 活性增强。miR-132 agomir 和/或 pGPH1-β-catenin 转染后，β-连环蛋白表达显著降低，Wnt/β-连环蛋白信号通路活性下降，Osterix 水平降低，ALP 表达和活性减弱，UC-MSCs 向 OB 的分化受到抑制。
UC-MSCs 向 OB 分化过程中，β-连环蛋白水平升高，miR-132 水平降低。上调 miR-132 通过抑制β-连环蛋白表达、减弱 Wnt/β-连环蛋白信号通路活性以及下调 Osterix 水平，抑制 UC-MSCs 的分化。
