MicroRNA-155 suppresses autophagy in chondrocytes by modulating expression of autophagy proteins.
MicroRNA-155 suppresses autophagy in chondrocytes by modulating expression of autophagy proteins.
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DOI：
10.1016/j.joca.2016.01.005
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发表时间：
2016-06
影响因子：
7
通讯作者：
Lotz MK
中科院分区：
文献类型：
--
作者：
D'Adamo S;Alvarez-Garcia O;Muramatsu Y;Flamigni F;Lotz MK
自噬功能障碍已在骨关节炎（OA）软骨中报道。本研究的目的是研究microRNA-155（miR-155），这是过度表达的OA，在人类软骨细胞自噬的调节作用。雷帕霉素（50 nM）和2-脱氧葡萄糖（2-DG）（5 mM）用于刺激原代人关节软骨细胞和T/C28 a2人软骨细胞系中的自噬。用LNA GapmeR或对miR-155特异的模拟物转染细胞，并通过LC 3蛋白质印迹和通过自噬空泡中的Cyto-ID®染料定量来评估自噬通量。通过实时PCR和蛋白质印迹分析自噬途径中预测的miR-155靶标的表达。在T/C28 a2细胞和人原代软骨细胞中，miR-155 LNA显著增加了由雷帕霉素和2-DG诱导的自噬通量，并且在miR-155模拟物转染后显著降低。miR-155对自噬的这些作用与抑制关键自噬调节因子的基因和蛋白表达有关，包括Ulk 1、FoxO 3、Atg 14、Atg 5、Atg 3、Gabarapl 1和Map 1 lc 3。MiR-155是软骨细胞中自噬的抑制剂，并有助于OA的发病机制。
Autophagy dysfunction has been reported in osteoarthritis (OA) cartilage. The objective of this study was to investigate the role of microRNA-155 (miR-155), which is overexpressed in OA, in the regulation of autophagy in human chondrocytes. Rapamycin (50nM) and 2-deoxyglucose (2-DG) (5mM) were used to stimulate autophagy in primary human articular chondrocytes and in the T/C28a2 human chondrocyte cell line. Cells were transfected with LNA GapmeR or mimic specific for miR-155 and autophagy flux was assessed by LC3 western blotting and by Cyto-ID® dye quantification in autophagic vacuoles. Expression of predicted miR-155 targets in the autophagy pathway were analyzed by real-time PCR and western blotting. Autophagy flux induced by rapamycin and 2-DG was significantly increased by miR-155 LNA, and significantly decreased after miR-155 mimic transfection in T/C28a2 cells and in human primary chondrocytes. These effects of miR-155 on autophagy were related to suppression of gene and protein expression of key autophagy regulators including Ulk1, FoxO3, Atg14, Atg5, Atg3, Gabarapl1, and Map1lc3. MiR-155 is an inhibitor of autophagy in chondrocytes and contributes to the pathogenesis of OA.